The determination of hydroxyproline in tissue and protein samples containing small proportions of this imino acid

Tailoring extracellular matrix niches: Impact of glycosaminoglycan content on multiple differentiation of human mesenchymal stem cells

Glycosaminoglycan (GAG) represents an important extracellular matrix (ECM), particularly in GAG-rich tissues such as nucleus pulposus and cartilage. The ratio of GAGs/hydroxyproline (HYP) is an indicator of the relative abundance of the space-filling GAG matrix to the fibrous collagen matrix in a particular tissue. Here, we hypothesize that ECM niche with different GAG/HYP ratios will affect the outcomes of multiple differentiation of human mesenchymal stem cells (hMSCs). Specifically, we fabricated collagen-based biomaterials with different GAG/HYP ratios, and differentiate hMSCs in these materials towards osteogenic, chondrogenic and discogenic lineages. In osteogenic differentiation, Collagen without GAG (GAG/HYP ratio 0) showed higher calcium (Ca) and phosphorus (P) deposition and Ca/P ratio, more biomimetic ultrastructure, and better osteogenic phenotypic expression. For chondrogenic differentiation, aminated collagen (aCol-GAG) with intermediate GAG content (GAG/HYP ratio 5.0:1) showed higher GAG deposition, more biomimetic ultrastructure, and better chondrogenic phenotype. In discogenic differentiation, aminated collagen-aminated hyaluronic acid (aHA)-GAG (aCol-aHA-GAG) with the highest GAG content (GAG/HYP ratio 19.8:1), showed intensive GAG deposition, biomimetic ultrastructure, and higher phenotypic marker expression. This study contributes to developing collagen-based biomimetic materials with different GAG/HYP ratios and suggests the use of tissue-specific GAG/HYP ratio as a scaffold design parameter for hMSCs-based musculoskeletal tissue engineering. (198 words).

Development of hepatic steatosis in normal and veinous livers of overfed female mule ducks

Following the various recent avian influenza crises, the shortage of male mule ducklings has led to the use of females, although these are not normally used mainly because of defects in the presentation of the final product. The aim of this study was to examine the evolution of hepatic steatosis induced by overfeeding in female mule ducks with or without a visible network of veins on the surface of lean or fatty livers. The overall evolution of hepatic steatosis (weight gain, gross biochemical composition) was strikingly similar in both types of liver. Histological observations confirm that in both types of livers, there is a steady increase in the accumulation of lipid droplets in hepatocytes throughout the period of overfeeding. At the same time, other parameters (fibrogenesis, measured by the accumulation of hydroxyproline; oxidative status, measured by the activities of the enzymes superoxide dismutase and catalase; contents of reduced and oxidised glutathione and level of hypoxia, measured with Hypoxia 1 and 2 Induced Factors) are also altered similarly in all samples. Nor did the overall activities of genes belonging to different metabolic pathways reveal any major differences when normal and veinous livers were compared. In conclusion, hepatic steatosis induced by overfeeding developed under very similar conditions in the normal and veinous livers of female mule ducks. However, these visible anatomical differences degrade the visual quality of the final product and make veinous livers less attractive to processors and consumers.

Performance, muscle metabolites, and beef quality of Nellore cull cows subjected to different finishing feeding durations

This study evaluated the performance, muscle metabolites, and beef quality of Nellore cull cows subjected to different finishing feeding durations. Twenty Nellore cows (initial body weight of 477.4 ± 49.6 kg) were randomly assigned to the three treatments: six as the control group (D0), seven finishing-fed for 28 d (D28), and seven finishing-fed for 56 d (D56). Parameters including dry matter intake, shrunk body weight, empty body weight (EBW), hot carcass weight (HCW), carcass shrinkage, muscle metabolites, and meat quality parameters in different aging times (0AT, 7AT, and 14AT) were assessed. Cull cows subjected to D28 and D56 treatments had greater EBW (P < 0.001) than D0. However, greater HCW (P = 0.004) and back fat thickness (P = 0.005) were detected in only D56 treatment compared to D0 and D28 treatments. As a result, the carcass pH was lower in the D56 treatment (P = 0.002) compared to D0 and D28 treatments. The Longissimus lumborum muscle of cull cows finished for 28 and 56 d showed a higher concentration of sugars (glucose-6-phosphate and fructose-6-phosphate), glycerol, and amino acids (leucine, alanine, isoleucine, valine, and aspartate). In conclusion, as the finishing period and aging time increased, there was a corresponding improvement in fat content and meat tenderness, respectively.

Synergistic healing: harnessing snail mucus enriched with carob extract for anti-inflammatory and antioxidant therapy in ulcerative colitis

BACKGROUND

Inflammatory bowel diseases (IBD), including ulcerative colitis, are characterized by chronic inflammation and oxidative stress, necessitating novel therapeutic approaches. This study explores the therapeutic potential of snail mucus derived from snails fed different concentrations of carob (SSCS) and compares its efficacy to aqueous carob extracts (AECS). Both SSCS and AECS are rich in bioactive compounds with potential anti-inflammatory, antioxidant and tissue-regenerative effects.

RESULTS

Snail mucus was found to be rich in collagen and allantoin, which are crucial for tissue repair and cell regeneration, whereas carob extracts contained high levels of phenolics, tannins and flavonoids, contributing to their antioxidant properties. In a rat model of acetic acid-induced ulcerative colitis, pretreatment with SSCS, AECS or sulfasalazine significantly alleviated colonic damage. The SSCS30% group exhibited the strongest protective effects, comparable to sulfasalazine, in reducing mucosal injury, inflammation and immune activation. Biochemical analyses demonstrated that SSCS30% effectively decreased systemic inflammation markers (CRP), pancreatic stress indicators (amylase) and liver enzyme levels (AST, ALT, ALP), while enhancing antioxidant defenses and preserving colonic sulfhydryl content.

CONCLUSION

These findings underscore the therapeutic potential of snail mucus, particularly from snails fed a 30% carob-enriched diet, as a promising natural therapy for IBD. Its potent anti-inflammatory, antioxidant and tissue-regenerative properties suggest that the use of SSCS30% could serve as an innovative approach for managing ulcerative colitis and other inflammatory disorders. These findings suggest that carob-enriched snail mucus could serve as a complementary therapy for ulcerative colitis patients, though clinical validation remains necessary. While these preclinical results are promising, further clinical studies are needed to validate the therapeutic potential of this natural combination in human ulcerative colitis. © 2025 Society of Chemical Industry.

The protective effects of melatonin against electromagnetic waves of cell phones in animal models: A systematic review

BACKGROUND

Due to the widespread use of cell phone devices today, numerous research studies have focused on the adverse effects of electromagnetic radiation on human neuropsychological and reproductive systems. In most studies, oxidative stress has been identified as the primary pathophysiological mechanism underlying the harmful effects of electromagnetic waves. This paper aims to provide a holistic review of the protective effects of melatonin against cell phone-induced electromagnetic waves on various organs.

METHODS

This study is a systematic review of articles chosen by searching Google Scholar, PubMed, Embase, Scopus, Web of Science, and Science Direct using the keywords 'melatonin', 'cell phone radiation', and 'animal model'. The search focused on articles written in English, which were reviewed and evaluated. The PRISMA process was used to review the articles chosen for the study, and the JBI checklist was used to check the quality of the reviewed articles.

RESULTS

In the final review of 11 valid quality-checked articles, the effects of melatonin in the intervention group, the effects of electromagnetic waves in the case group, and the amount of melatonin in the chosen organ, i.e. brain, skin, eyes, testis and the kidney were thoroughly examined. The review showed that electromagnetic waves increase cellular anti-oxidative activity in different tissues such as the brain, the skin, the eyes, the testis, and the kidneys. Melatonin can considerably augment the anti-oxidative system of cells and protect tissues; these measurements were significantly increased in control groups. Electromagnetic waves can induce tissue atrophy and cell death in various organs including the brain and the skin and this effect was highly decreased by melatonin.

CONCLUSION

Our review confirms that melatonin effectively protects the organs of animal models against electromagnetic waves. In light of this conclusion and the current world-wide use of melatonin, future studies should advance to the stages of human clinical trials. We also recommend that more research in the field of melatonin physiology is conducted in order to protect exposed cells from dying and that melatonin should be considered as a pharmaceutical option for treating the complications resulting from electromagnetic waves in humans.

Cutaneous Wound-Healing Activity of Quercetin-Functionalized Bimetallic Nanoparticles

Quercetin, a natural flavonol, is reported to have significant antioxidant and anti-inflammatory activity, which further aids in its good wound-healing properties via acting on acute as well as chronic inflammatory phases. The current study is focused on understanding the potential of the green-synthesized iron and zinc oxide bimetallic (i.e., zinc ferrite) nanoparticles of quercetin (ZFQNP) on wound healing by an in vivo study model. Bimetallic quercetin nanoparticles were prepared by the co-precipitation method and characterized by UV-visible spectroscopy, scanning electron microscopy (SEM), and dynamic light scattering (DLS) analyses. Synthesized ZFQNP was utilized to prepare the ointment for topical application, and wound-healing activity was evaluated by using the excisional wound method in Wistar rats. The binding affinity of quercetin was ascertained against various wound-healing protein targets by molecular docking. Characterization data confirmed the synthesis of bimetallic ZFQNP of an irregular shape. Molecular docking studies showed satisfactory binding potential of quercetin with selected molecular targets. The study results of various parameters corroborated the significant wound-healing properties of ZFQNP, possibly attributed to the promising binding potential of quercetin with vital wound-healing targets. The study demonstrated that the quercetin bimetallic nanoparticles could provide a promising wound-healing effect.

Differential Expression of Splicing Factor Gene by Estrogen Receptor Activation Factor

The functional role of estrogen receptor activation factor (E-RAF), a 66 kDa protein in mediating the biological actions of estrogen and progesterone in goat uterus, has been highlighted in this work. Here we report that E-RAF stimulates the expression of splicing factor gene, arginine/serine rich in goat uterine nuclei (GenBank Accession No. MT473439). cDNA subtractive hybridization method using nuclear run-on transcription assay was used to identify the differentially expressed genes. The upregulation of the splicing factor gene was demonstrated further using a PCR-based nuclear run-on transcription system. Confocal microscopic analysis has confirmed the endoplasmic reticulum as the primary site of intracellular location of E-RAF. The effect of estrogen and progesterone on the intracellular distribution of E-RAF and the molecular mechanisms that underlie the transport of E-RAF to nucleus in the presence of progesterone has been studied. Our results offer a new perspective in steroid hormone action in uterus.

Measurement of advanced glycation end products (AGEs) accumulated in dentin collagen

OBJECTIVE

In the Maillard reaction, reducing sugars bind to proteins in a non-enzymatic manner, and the final products are collectively named, advanced glycation end products (AGEs). AGEs accumulate in the human body with age and cause various disorders in tissues and cells. In this study, pentosidine, an AGE that can be stably measured, was used to investigate the differences in pentosidine accumulation within dentin, and whether the results can indicate age.

METHODS

High-performance liquid chromatography was used to measure pentosidine, an AGE that accumulates in dentin collagen, in extracted teeth with no caries and a clear history.

RESULTS

The dentin pentosidine concentration increased with age, with a higher pentosidine concentration observed at the enamel-dentin junction aspect than at the pulp cavity aspect. A close correlation was observed between the dentin pentosidine level and age.

CONCLUSIONS

These findings suggest the utility of measuring accumulation of AGEs in dentin collagen as an indicator of age.

Hippophae rhamnoides L. leaf extract augments dermal wound healing in streptozocin-induced diabetic rats

OBJECTIVE

The present investigation was undertaken to determine the healing efficacy of Hippophae rhamnoides L. (sea buckthorn (SBT)) leaf aqueous lyophilised extract (SBTL-ALE) on a diabetic wound model in rats. The effect of SBTL-ALE was also evaluated on human epithelial cell lines (A431) by using in vitro wound closure and transwell migration assays.

METHOD

A total of four full-thickness excision-type wounds were created on the dorsal surface of streptozocin-induced diabetic rats. The animals were divided into two groups: control rats treated with soft white petroleum jelly and experimental rats treated with SBTL-ALE (5.0%, weight/weight) ointment applied topically, twice daily for seven days.

RESULTS

SBTL-ALE significantly (p<0.05) accelerated the migration of epithelial cells in in vitro wound closure and transwell migration assays. Further, SBTL-ALE augmented the healing process by significantly (p<0.05) enhanced wound area contraction, faster complete epithelial closure, increased hydroxyproline (collagen) and hexosamine levels in diabetic rats. Histopathological findings confirmed the healing potential of SBTL-ALE. Immunohistochemical analyses showed increased expression of transforming growth factor (TGF)-β and α-smooth muscle actin in SBTL-ALE-treated wounds of diabetic rats. Superoxide dismutase, catalase and reduced glutathione levels increased, whereas reactive oxygen levels were decreased significantly (p<0.05) in SBTL-ALE-treated wounds compared to diabetic controls, which conferred redox homeostasis.

CONCLUSION

Our results suggest that SBTL-ALE accelerated transdermal wound healing in diabetic rats by increasing the rate of wound contraction, enhancing levels of collagen, hexosamine and endogenous antioxidants, and reducing oxidative stress.

Salvia hispanica L. (chia) seed have beneficial effects upon visceral adipose tissues extracellular matrix disorders and inflammation developed in a sucrose-rich diet-induced adiposity rodent model

We have previously demonstrated that dietary Salvia hispanica L. (chia) seed, rich in α-linolenic acid (ALA), was able to reduce visceral adiposity and improves insulin sensitivity in a rodent experimental model of adiposity induced by the administration of a sucrose-rich diet (SRD). The evidence suggests that the pathological expansion of visceral adipose tissue (VAT) is accompanied by changes in the extracellular matrix (ECM) components, which can lead to fibrosis, and/or a greater expression of pro-inflammatory adipokines. The aim of the present work was to evaluate the effect of chia seed administration upon key components and modulators of ECM remodeling and inflammation in different white adipose tissues (WAT) (epididymal-eWAT- and retroperitoneal-rWAT-) in a SRD-induced adiposity rodent model. The results showed that chia seed reduced the increased hydroxyproline levels observed in SRD-fed group and this was accompanied by changes in the activity/expression of matrix metalloproteinases MMP-2 and MMP-9. No changes were observed in transforming growth factor β (TGF-β) expression levels. In addition, this nutritional intervention was able to reduce the levels of PAI-1 and MCP-1, and to increase the levels of adiponectin in both VAT. An increase in the ratio of n-3/n-6 polyunsaturated fatty acids in the membrane phospholipids of both VAT was also observed. The present study demonstrated that chia seed have anti-fibrotic and anti-inflammatory actions in the VAT which could play a key role in the amelioration of visceral adiposity and whole-body insulin insensitivity developed in SRD-fed rats.

Optimising compensatory growth in pastoral beef production systems: insights into feed efficiency, body composition, carcass characteristics and meat quality attributes

Exploitation of compensatory growth (CG) is a widely practised management strategy in beef production, especially under pastoral conditions due to its potential to reduce feed costs. The aim of this experiment was to evaluate the effect of nutritional restriction during backgrounding in Angus steers slaughtered at either similar age and/or similar BW on feed efficiency, body composition, carcass characteristics and meat quality attributes under either a forage or feedlot-based finishing diet. Eighty steers (BW: 444 ± 39 kg, age: 18 ± 1 months) were blocked and randomly assigned within block to either an optimal (0.6-0.7 kg/day) or suboptimal (0.3-0.4 kg/day) growth rate, during 97 days of backgrounding. Following, half of the steers in each group were finished on a forage diet while the other half were finished on feedlot-based diet. Half of the steers in each treatment were then slaughtered at similar age (24 months), whilst all remaining steers were slaughtered at similar BW (∼620 kg). Two extra slaughters were done with other representative steers on day 0 and day 97, to provide baseline parameters for carcass and non-carcass measurements. During the backgrounding period, optimal steers gained more than suboptimal (P < 0.01), resulting in higher BW and hot carcass weight (HCW; P < 0.01). During the finishing period, the suboptimal group increased BW gain (P < 0.01) and displayed an improved feed conversion ratio (FCR; P < 0.01). Differences (P < 0.01) in BW and HCW remained between the treatments when slaughtered at a similar age. When the steers were slaughtered at similar BW, after additional days of finishing for the suboptimal groups, no differences (P > 0.05) in backgrounding treatment on HCW, carcass grading, body composition or FCR for the entire period (backgrounding and finishing) were apparent. Indeed, no differences (P > 0.05) by backgrounding growth strategy were observed for any meat quality variables assessed using instrumental or sensory evaluations. During the finishing period, feedlot steers had increased (P < 0.01) BW and HCW gains, improved (P < 0.05) FCR and carcass grading, and had higher (P < 0.05) HCW compared to forage finished steers. However, no differences (P > 0.05) were observed for any meat quality variables assessed by finishing system. Overall, exploiting CG within pasture-based beef cattle production systems improves growth rate and FCR in both forage and feedlot finishing. Suboptimal backgrounded steers required additional days on feed to achieve similar BW to their contemporaries. Nevertheless, at similar BW, there were no residual differences in body composition, FCR during the entire period, meat tenderness or overall meat liking because of the backgrounding conditions.

Sambucus nigra-Lyophilized Fruit Extract Attenuated Acute Redox-Homeostatic Imbalance via Mutagenic and Oxidative Stress Modulation in Mice Model on Gentamicin-Induced Nephrotoxicity

Background: Gentamicin (GM) administration is associated with decreased metabolism, increased oxidative stress, and induction of nephrotoxicity. Sambucus nigra L., containing flavonoids, anthocyanins, and phytosterols, possesses antioxidant and anti-inflammatory potential. Objectives: The present study aimed to investigate the nephroprotective and anti-inflammatory potential of lyophilized Sambucus nigra fruit extract (S. nigra extract) to reduce acute oxidative stress and residual toxicity of GM in a 7-day experimental model in Balb/c rodents. Methods: The S. nigra extract was lyophilized (300 rpm; 10 min; -45 °C) to improve pharmacological properties. Balb/c mice were divided into four (n = 6) groups: controls; S. nigra extract per os (120 mg kg-1 day-1 bw); GM (200 mg kg-1 day-1 bw) (4); and GM + S. nigra therapy. The activities of antioxidant and renal enzymes, cytokines, and levels of oxidative stress biomarkers-Hydroxiproline, CysC, GST, KIM-1, PGC-1α, MDA, GSPx-were analyzed by ELISA tests. The ROS and RNS levels, as well as 5-MSL-protein oxidation, were measured by EPR spectroscopy. Results: The antioxidant-protective effect of S. nigra extract (120 mg kg-1) was demonstrated by reduced MDA, ROS, and RNS and increased activation of endogenous enzymes. Furthermore, S. nigra extract significantly reduced the expression of IL-1β, IL-6, IL-10, TNF-α, IFN-γ, and KIM-1 and regulated collagen/protein (PGC-1α and albumin) deposition in renal tissues. Conclusions: Histological evaluation confirmed that S. nigra (120 mg kg-1) attenuated renal dysfunction and structural damage by modulating oxidative stress and acute inflammation and could be used as an anti-fibrotic alternative in GM nephrotoxicity.

Hydrolyzed collagen as a partial fat substitute in chicken burgers produced with white striping meat

White striping (WS) is an anomaly characterized by the appearance of white striations in the Pectoralis major muscles. This study aimed to evaluate the effect of animal fat replacement (chicken skin) with hydrolyzed collagen (HC, 0, 50 and 75%) on the characteristics of burgers with normal chicken breast fillets (FN) and WS. The samples were subjected to physical-chemical characterization, oxidative stability (TBARS), texture, and sensory profile. The utilization of WS meat increased the pH values, lipid content, and oxidation throughout storage, but it did not impair the sensory acceptance and sensory profile of the products. Adding HC reduced the pH in the formulations, changed the chemical composition (lower moisture and lipid content and higher protein and collagen content), and increased the texture parameters (hardness and chewiness). The formulations with 50% fat replacement showed similar sensory acceptance and purchase intention to the control products and were characterized by the typical texture and mild aroma and flavor. The results suggest that WS chicken meat and HC can be used to produce hamburgers with 50% replacement of animal fat without compromising the quality of the products.

Amino Acid Uptake Limitations during Human Mesenchymal Stem Cell-Based Chondrogenesis

A mino acids are the essential building blocks for collagen and proteoglycan, which are the main constituents for cartilage extracellular matrix (ECM). Synthesis of ECM proteins requires the uptake of various essential/nonessential amino acids. Analyzing amino acid metabolism during chondrogenesis can help to relate tissue quality to amino acid metabolism under different conditions. In our study, we studied amino acid uptake/secretion using human mesenchymal stem cell (hMSC)-based aggregate chondrogenesis in a serum-free induction medium with a defined chemical formulation. The initial glucose level and medium-change frequency were varied. Our results showed that essential amino acid uptake increased with time during hMSCs chondrogenesis for all initial glucose levels and medium-change frequencies. Essential amino acid uptake rates were initial glucose-level independent. The DNA-normalized glycosaminoglycans and hydroxyproline content of chondrogenic aggregates correlated with cumulative uptake of leucine, valine, and tryptophan regardless of initial glucose levels and medium-change frequencies. Collectively, our results show that amino acid uptake rates during in vitro chondrogenesis were insufficient to produce a tissue with an ECM content similar to that of human neonatal cartilage or adult cartilage. Furthermore, this deficiency was likely related to the downregulation of some key amino acid transporters in the cells. Such deficiency could be partially improved by increasing the amino acid availability in the chondrogenic medium by changing culture conditions.

COX-2 targeted therapy for diabetic foot ulcers using T7-enhanced CS-PVA membranes

Diabetic foot ulcers can lead to severe complications, including infection, gangrene, and even amputation, significantly impacting patients' quality of life. The application of anti-inflammatory compounds loaded into chitosan membranes offers targeted therapeutic effects, reducing inflammation and promoting tissue regeneration. This study evaluates the therapeutic efficacy of T7, a selective COX-2 inhibitor, incorporated into chitosan-polyvinylalcohol (CS-PVA) membranes for diabetic wound treatment. Cytotoxicity analysis showed high cell viability across various T7 concentrations, indicating minimal cytotoxicity. In silico pharmacology identified 98 potential inflammation-related targets for T7, further supported by GO and KEGG enrichment analyses. Developmental toxicity tests on zebrafish embryos indicated no significant toxicity up to 100 µM concentration. SEM and FTIR analyses confirmed the successful incorporation of T7 into the CS-PVA membrane, while XRD analysis indicated structural stability. The drug release assay demonstrated a sustained release profile, crucial for prolonged therapeutic efficacy. Antibacterial activity assays revealed significant inhibition of common pathogens. In vivo wound healing assays showed accelerated wound closure and enhanced collagen deposition, with histological and immunohistochemistry analyses supporting improved tissue architecture and reduced inflammation. Gene expression analysis confirmed reduced inflammatory markers. These findings suggest that T7-loaded CS-PVA membranes offer a promising, multifaceted approach to diabetic wound treatment, combining anti-inflammatory, antimicrobial, and collagen-promoting properties for effective wound healing.

Harnessing the Power of Saussurea obvallata Zinc Oxide Nanoparticles for Accelerated Wound Healing and Antimicrobial Action

Introduction

Zinc oxide nanoparticles (ZnONPs) have been the subject of substantial research by virtue of their utility across extensive downstream applications. Moreover, the ZnONPs are inexpensive, reliable, and easy to produce. Green synthesis employing biological systems, particularly plant extracts, has arisen as a subject of study in nanotechnology and is gaining importance due to its multiple applications in biology, chemistry, physics, and medicine.

Methods

Aqueous extract of S. obvallata was prepared and ZnONPs were synthesised using zinc acetate as a substrate. UV-Vis spectrophotometric measurement confirmed the production of ZnONPs. The ZnONPs were characterized by employing SEM, EDS, XRD, and FTIR. The ZnONPs were screened for its antimicrobial and wound healing potential.

Results

The peak of absorbance for UV-Vis was observed at 370 nm. The average dimension of the particles was found to be 22.58 nm. The antibacterial activity of ZnONPs was efficient in countering a broad spectrum of bacteria and the fungi C. albicans. The results of in vitro and in vivo wound healing assays indicate that the ZnONPs possess potent wound healing potential. In the cell migration assay, the percentage of wound closure was observed to be 84.70% (p < 0.001) for ZnONPs compared to the untreated group (8.12%). In the excision wound healing rat model, the animals treated with ZnONPs and Povidone-Iodine showed a significant (p < 0.01) wound contraction in comparison to the untreated animals.

Discussion

The ZnONPs promoted wound healing processes and showed promise as a therapeutic agent. However, further research is needed to understand the mechanisms of action and evaluate the long-term safety and effectiveness of ZnONPs in wound healing applications. By using renewable biological materials, the green synthesis of ZnONPs minimizes the need for synthetic reagents and lowers the total carbon footprint related to the production of nanoparticles.

Mechanistic insights on stabilization and destabilization effect of ionic liquids on type I collagen fibrils

Tuned assembly of collagen has tremendous applications in the field of biomedical and tissue engineering owing to its targeted biological functionalities. In this study, ionic liquids choline dihydrogen citrate (CDHC) and diethyl methyl ammonium methane sulfonate (AMS) have been used to regulate the self-assembly of collagen at its physiological pH by probing the assembled systems at certain concentration ratios of ionic liquids and the systems were studied using various characterization methods. Due to interaction with collagen, choline dihydrogen citrate causes delay in the collagen fibrillisation process showing no binding interactions with collagen. In contrast, diethyl methyl ammonium methane sulfonate shows crosslinking effect on collagen fibrillisation due to the electrostatic interaction with the tetrahedral hydration shell of collagen moieties. From rheological studies it was observed that the AMS treated collagen fibril at 1:1 % (w/v) has highest linear viscoelastic range, this can bear the stress under high strain compare to native collagen fibril as well as all CDHC composites. For a sustainable biomaterial or bio-scaffold, mechanical property plays pivotal role on it and from our experimental analysis we found certain composites of ionic liquid treated collagen fibrillar assembly which may act as a sustainable biomaterial or bio-scaffold. It was also evolved that, how the structure-function relationship of ionic force modulated fibrillar assembly controlling the mechanical properties of the tuned system. This self-assembled, ionic-liquid treated collagen-fibrillar system would accelerate various force modulated fibrillar network study, for mimicking the ECM and tissue engineering application.

Quality and stability of meat products prepared with chicken fillets affected by white striping myopathy

This study aimed to evaluate the quality and oxidative stability of chicken burger and mortadella prepared with fillets affected by white striping (WS) myopathy as compared with products prepared with normal fillets (control). There were no differences in pH, L*, or b* between treatments (WS vs. control); however, water holding capacity was higher in control burgers and mortadellas. In burgers, the use of WS fillet led to an increase in lipid content and a reduction in moisture content. Mortadella formulations were similar in terms of proximate composition. Addition of WS fillets did not influenced water activity in any of the products. Differences (p < 0.05) were observed for texture profile: WS burgers had 35% lower firmness and 32% lower chewiness than control burgers, and WS mortadellas had lower resilience. Cooking yield and shrinkage were similar between WS and control burgers. As for lipid oxidation, it was found that WS burgers were more stable than control formulations. Mortadella formulations showed a similar behavior of lipid oxidation during storage, with higher values observed after 65 days of storage in both treatments. Utilization of WS fillets for the preparation of burgers and mortadellas is a viable alternative that does not compromise product quality or oxidative stability.

Characterization of pediatric porcine pulmonary valves as a model for tissue engineered heart valves

Heart valve tissue engineering holds the potential to transform the surgical management of congenital heart defects affecting the pediatric pulmonary valve (PV) by offering a viable valve replacement. While aiming to recapitulate the native valve, the minimum requirement for tissue engineered heart valves (TEHVs) has historically been adequate mechanical function at implantation. However, long-term in situ functionality of TEHVs remains elusive, suggesting that a closer approximation of the native valve is required. The realization of biomimetic engineered pediatric PV is impeded by insufficient characterization of healthy pediatric tissue. In this study, we comprehensively characterized the planar biaxial tensile behaviour, extracellular matrix (ECM) composition and organization, and valvular interstitial cell (VIC) phenotypes of PVs from piglets to provide benchmarks for TEHVs. The piglet PV possessed an anisotropic and non-linear tension-strain profile from which material constants for a predictive constitutive model were derived. The ECM of the piglet PV possessed a trilayer organization populated by collagen, glycosaminoglycans, and elastin. Biochemical quantification of ECM content normalized to wet weight and DNA content of PV tissue revealed homogeneous distribution across sampled regions of the leaflet. Finally, VICs in the piglet PV were primarily quiescent vimentin-expressing fibroblasts, with a small proportion of activated α-smooth muscle actin-expressing myofibroblasts. Overall, piglet PV properties were consistent with those reported anecdotally for pediatric human PVs and distinct from those of adult porcine and human PVs, supporting the utility of the properties determined here to inform the design of tissue engineered pediatric PVs. STATEMENT OF SIGNIFICANCE: Heart valve tissue engineering has the potential to transform treatment for children born with defective pulmonary valves by providing living replacement tissue that can grow with the child. The design of tissue engineered heart valves is best informed by native valve properties, but native pediatric pulmonary valves have not been fully described to date. Here, we provide comprehensive characterization of the planar biaxial tensile behaviour, extracellular matrix composition and organization, and valvular interstitial cell phenotypes of pulmonary valves from piglets as a model for the native human pediatric valve. Together, these findings provide standards that inform engineered heart valve design towards generation of biomimetic pediatric pulmonary valves.

Preparation and Characterization of Hydroxylated Recombinant Collagen by Incorporating Proline and Hydroxyproline in Proline-Deficient Escherichia coli

Collagen possesses distinctive chemical properties and biological functions due to its unique triple helix structure. However, recombinant collagen expressed in Escherichia coli without post-translational modifications such as hydroxylation lacks full function since hydroxylation is considered to be critical to the stability of the collagen triple-helix at body temperature. Here, a proline-deficient E. coli strain was constructed and employed to prepare hydroxylated recombinant collagens by incorporating proline (Pro) and hydroxyproline (Hyp) from the culture medium. By controlling the ratio of Pro to Hyp in the culture medium, collagen with different degrees of hydroxylation (0-88%) can be obtained. When the ratio of Pro and Hyp was adjusted to 12:8 mM, the proline hydroxylation rate of recombinant human collagen (rhCol, 55 kDa) ranged from 40-50%, which was also the degree of natural collagen. After proline hydroxylation, both the thermal stability and cell binding of rhCol were significantly enhanced. Notably, when the hydroxylation rate approached that of native human collagen (40-50%), the improvements were most pronounced. Moreover, the cell binding of rhCol with a hydroxylation rate of 43% increased by 29%, and the melting temperature (Tm) rose by 5 °C compared to the non-hydroxylated rhCol. The system achieved a yield of 1.186 g/L of rhCol by batch-fed in a 7 L fermenter. This innovative technology is expected to drive the development and application of collagen-related biomaterials with significant application value in the fields of tissue engineering, regenerative medicine, and biopharmaceuticals.

Wound healing potential of silver nanoparticles from Hybanthus enneaspermus on rats

In this study, we green synthesized silver nanoparticles (Ag Nps) from Hybanthus enneaspermus leaves (HE-Ag NPs) and evaluated their antimicrobial and wound-healing properties. The synthesized HE-Ag NPs were characterized using various techniques, revealing face-centered polygonal structures, a well-dispersed appearance, and an average particle size of 42-51 nm. The antimicrobial effects of HE-Ag NPs and their embedded cotton fabrics were tested against several pathogens, showing effective inhibition of growth. The cytotoxicity and anti-inflammatory properties of HE-Ag NPs were assessed using MTT assays on L929 and RAW 264.7 cells and by measuring inflammatory cytokine levels in LPS-treated RAW 264.7 cells. HE-Ag NPs did not affect the viability of L929 and RAW 264.7 cells and significantly reduced inflammatory cytokine levels. In vivo studies using an excision wound model demonstrated that HE-Ag NPs-loaded ointment significantly increased hydroxyproline, total protein, and antioxidant levels and enhanced the wound contraction rate. These findings suggest that HE-Ag NPs have potent antimicrobial properties and promote wound healing, indicating their potential for use in topical ointments for wound care.

13C Metabolic Flux Analysis in Chondrocytes Reveals a Novel Switch in Metabolic Phenotype

Chondrocytes are typically known for their anaerobic metabolism both in vivo and under culture conditions in vitro. However, chondrocytes have been shown to display greater biosynthetic activity when subjected to conditions that elicit aerobic metabolism. We have previously shown that tissue formation by chondrocytes can be upregulated by controlling nutrient availability and that this response arises from changes in glucose metabolism. The aim of the present study was to further characterize these changes through 13C-metabolic flux analysis (13C-MFA), as well as to determine the most optimal response. Primary bovine chondrocytes were grown in scaffold-free high-density tissue culture. [U-13C] glucose labeling experiments were combined with a tissue-specific metabolic network model to carry out 13C-MFA under varying levels of nutrient availability. 13C-MFA results demonstrated that when subjected to increasing nutrient availability, chondrocytes switch from a predominately anaerobic to a mixed aerobic-anaerobic phenotype. This metabolic switch was attributed to the saturation of the lactate fermentation pathway and metabolite overflow toward the tricarboxylic acid cycle. This effect appears to be similar to, but the inverse of, the Crabtree effect ("inverse Crabtree effect"). The relationships between metabolic flux and nutrient availability were then utilized to identify culture conditions that promote enhanced tissue formation. This novel metabolic effect presents a simple but effective approach for enhancing the biosynthetic response of chondrocytes-a key requirement to develop functional engineered cartilaginous tissue for joint resurfacing.

Green synthesis of zinc oxide nanoparticles from Wodyetia bifurcata fruit peel extract: multifaceted potential in wound healing, antimicrobial, antioxidant, and anticancer applications

This study focuses on the synthesis, characterization, and use of zinc oxide nanoparticles (ZnONPs) derived from W. bifurcata fruit peel extract. ZnONPs are frequently synthesized utilizing a green technique that is both cost-effective and ecologically friendly. ZnONPs were characterized utilizing analytical techniques. Ultra Violet visible (UV-Vis) spectra showed peaks at 364 nm, confirming the production of ZnONPs. Scanning Electron Microscope analysis indicated that the nanoparticles generated were spherical/agglomerated, with diameters ranging from 11 to 25 nm. FTIR spectroscopy was used to identify the particular functional groups responsible for the nanoparticles' reduction, stabilization, and capping. Phytochemical analysis of the extract revealed that flavonoids, saponins, steroids, triterpenoids, and resins were present. The antibacterial activity of W. bifurcata synthesised nanoparticles was evaluated against pathogenic bacteria. The ZnONPs antioxidant activity was assessed using DPPH assay. The in vitro cytotoxicity was assessed against prostate cancer PC3 cells. The wound healing potential was assessed by employing in vitro scratch assay and in vivo excision model in Wistar rats. Because of its environmentally benign production, low toxicity, and biocompatibility, ZnONPs exhibited potential antibacterial, antioxidant, anticancer, and wound healing activities, indicating that they could be used in cancer treatment and wound management. Further study is required to examine the fundamental mechanisms and evaluate the safety and effectiveness of the test sample in clinical situations.

IBPA a mutual prodrug of ibuprofen and acetaminophen alleviates inflammation, immune dysregulation and fibrosis in preclinical models of systemic sclerosis

Systemic sclerosis (SSc) is a devastating autoimmune illness with a wide range of clinical symptoms, including vascular abnormalities, inflammation, and persistent and progressive fibrosis. The disease's complicated pathophysiology makes it difficult to develop effective therapies, necessitating research into novel therapeutic options. Molecular hybridization is a strategy that can be used to develop new drugs that act on two or multiple targets and represents an interesting option to be explored for the treatment of complex diseases. We aimed to evaluate the effects of a hybrid mutual prodrug of ibuprofen and acetaminophen (IBPA) in peripheral blood mononuclear cells (PBMC) isolated from SSc patients, and in an in vivo model of SSc induced in BALB/c mice by intradermal injections of hypochlorous acid (HOCl) for 6 weeks. The mice were treated at the same time with daily intraperitoneal injections of IBPA (40 mg/kg). Pulmonary and skin fibrosis as well as immune responses were evaluated. IBPA significantly decreased the release of cytokines in PBMC culture supernatants from SSc patients after stimulation with phytohemagglutinin-M (IL-2, IL-4, IL-6, IL-10, IL-13, IL-17A, TNF and IFN-γ).In HOCl-induced SSc, IBPA treatment prevented dermal and pulmonary fibrosis, in addition to reducing CD4 + T and B cells activation and reversing the M2 polarization of macrophages in spleen cells, and inhibiting IFN-γ secretion in splenocyte cultures. These results show the anti-inflammatory and antifibrotic effects of IBPA in SSc and highlight the therapeutic potential of this mutual prodrug, providing support for future studies.

Roles of collagen cross-links and osteon collagen/lamellar morphotypes in equine third metacarpals in tension and compression tests

Many bones experience bending, placing one side in net compression and the other in net tension. Because bone mechanical properties are relatively reduced in tension compared with compression, adaptations are needed to reduce fracture risk. Several toughening mechanisms exist in bone, yet little is known of the influences of secondary osteon collagen/lamellar 'morphotypes' and potential interplay with intermolecular collagen cross-links (CCLs) in prevalent/predominant tension- and compression-loaded regions. Paired third metacarpals (MC3s) from 10 adult horses were prepared for mechanical testing. From one MC3/pair, 5 mm cubes were tested in compression at several mid-shaft locations. From contralateral bones, dumbbell-shaped specimens were tested in tension. Hence, habitual/natural tension- and compression-loaded regions were tested in both modes. Data included: elastic modulus, yield and ultimate strength, and energy absorption (toughness). Fragments of tested specimens were examined for predominant collagen fiber orientation (CFO; representing osteonal and non-osteonal bone), osteon morphotype score (MTS, representing osteonal CFO), mineralization, porosity and other histological characteristics. As a consequence of insufficient material from tension-tested specimens, CCLs were only examined in compression-tested specimens (HP, hydroxylysylpyridinoline; LP, lysylpyridinoline; PE, pentosidine). Among CCLs, only LP and HP/LP correlated significantly with mechanical parameters: LP with energy absorption, HP/LP with elastic modulus (both r=0.4). HP/LP showed a trend with energy absorption (r=-0.3, P=0.08). HP/LP more strongly correlated with osteon density and mineralization than CFO or MTS. Predominant CFO more strongly correlated with energy absorption than MTS in both testing modes. In general, CFO was found to be relatively prominent in affecting regional toughness in these equine MC3s in compression and tension.

Alpha-cyperone mitigates renal ischemic injury via modulation of HDAC-2 expression in diabetes: Insights from molecular dynamics simulations and experimental evaluation

Chronic diabetes mellitus is reported to be associated with acute kidney injury. The enzyme histone deacetylase-2 (HDAC-2) was found to be upregulated in diabetes-related kidney damage. Alpha-cyperone (α-CYP) is one of the active ingredients of Cyperus rotundus that possesses antioxidant and anti-inflammatory effects. We evaluated the effect of α-CYP on improving oxidative stress and tissue inflammation following renal ischemia/reperfusion (I/R) injury in diabetic rats. The effect of α-CYP on HDAC-2 expression in renal homogenates and in the NRK-52 E cell line was evaluated following renal I/R injury and high glucose conditions, respectively. Molecular docking was used to investigate the binding of α-CYP with the HDAC-2 active site. Both renal function and oxidative stress were shown to be impaired in diabetic rats due to renal I/R injury. Significant improvements in kidney/body weight ratio, creatinine clearance, serum creatinine, blood urea nitrogen (BUN), and uric acid were observed in diabetic rats treated with α-CYP (50 mg/kg) two weeks prior to renal I/R injury. α-CYP treatment also improved histological alterations in renal tissue and lowered levels of malondialdehyde, myeloperoxidase, and hydroxyproline. Treatment with α-CYP suppressed the increased HDAC-2 expression in the renal tissue of diabetic rats and in the NRK-52 E cell line. The molecular docking reveals that α-CYP binds to HDAC-2 with good affinity, ascertained by molecular dynamics simulations and binding free energy analysis. Overall, our data suggest that α-CYP can effectively prevent renal injury in diabetic rats by regulating oxidative stress, tissue inflammation, fibrosis and inhibiting HDAC-2 activity.

Effect of 'Procumbenase' a serine protease from Tridax procumbens aqueous extract on wound healing: A scar free healing of full thickness wounds

Wound healing involves several cellular and molecular pathways. Tridax procumbens activates genetic pathways with antibacterial, antioxidant, anticancer, and anti-inflammatory properties, aiding wound healing. This study purified Procumbenase, a serine protease from T. procumbens extract, using gel filtration (Sephadex G-75) and ion exchange (CM-Sephadex C-50) chromatography. Characterization involved analyses of protease activity, RP-HPLC, SDS-PAGE, gelatin zymogram, PAS staining, mass spectrometry, and circular dichroism. Optimal pH and temperature were determined. Protease type was identified using inhibitors. Wound-healing potential was evaluated through tensile strength, wound models, hydroxyproline estimation, and NIH 3T3 cell scratch analysis. In incision wound rat models, Procumbenase increased tensile strength on day 14 more than saline and Povidone‑iodine. It increased wound contraction by 89 % after 10 days in excision wound models, attaining full contraction by day 15 and closure by day 21. Scarless wound healing was enhanced by 18 days of epithelialization against 22 and 21 days for saline and povidone‑iodine. Procumbenase increased hydroxyproline concentration 2.53-fold (59.93 ± 2.89 mg/g) compared to saline (23.67 ± 1.86 mg/g). In NIH 3 T3 cell scratch assay, Procumbenase increased migration by 60.93 % (50 μg) and 60.57 % (150 μg) after 48 h. Thus, Procumbenase is the primary bioactive molecule in T. procumbens, demonstrates scar-free wound healing properties.

Chondrogenic potential of superficial versus cartilage layer cells of the temporomandibular joint condyle in photopolymerizable gelatin-based hydrogels

The objectives of this study were to compare the chondrogenic potential of cells derived from different layers of Mandibular condyle cartilage and to gain further understanding of the impact of chondrogenic cues when embedded into a novel hydrogel scaffold (PGH, a polymer blend of poly (ethylene glycol), gelatin, and heparin) compared to a gelatin hydrogel scaffold (GEL). Cartilage layer cells (CLCs) and fibroblastic superficial layer cells (SLCs) were harvested from the mandibular condyle of boer goats obtained from a local abattoir. After expansion, cells were seeded into PGH and GEL hydrogels and cultured in chondrogenic media for 3 weeks. Scaffolds were harvested at 0, 1, and 3 week(s) and processed for gross appearance, histochemical, biochemical, and mechanical assays. In terms of chondrogenesis, major differences were observed between scaffold materials, but not cell types. Glycosaminoglycan (GAG) staining showed GEL scaffolds deposited GAG during the 3 week period, which was also confirmed with the biochemical testing. Moreover, GEL scaffolds had significantly higher compressive modulus and peak stress than PGH scaffolds at all time points with the largest difference seen in week 3. It can be concluded that GEL outperformed PGH in chondrogenesis. It can also be concluded that materials play a more important role in the process of chondrogenesis than the tested cell populations. Fibroblastic SLCs were shown to have similar chondrogenic potential as CLCs cells, suggesting a rich pool of progenitor cells in the superficial fibroblastic layer capable of undergoing chondrogenesis given appropriate physical and chemical cues.

Development of hepatic steatosis in male and female mule ducks after respective force-feeding programs

Male and female mule ducks were subjected to a force-feeding diet to induce liver steatosis as it is generally done only with male ducks for the production of foie gras. The different biochemical measurements indicated that the course of hepatic steatosis development was present in both sexes and associated with a huge increase in liver weight mainly due to the synthesis and accumulation of lipids in hepatocytes. In livers of male and female ducks, this lipid accumulation was associated with oxidative stress and hypoxia. However, certain specific modifications (kinetics of lipid droplet development and hepatic inflammation) indicate that female ducks may tolerate force-feeding less well, at least at the hepatic level. This is in contradiction with what is generally reported concerning hepatic steatosis induced by dietary disturbances in mammals but could be explained by the very specific conditions imposed by force-feeding. Despite this, force-feeding female ducks seems entirely feasible, provided that the final quality of the product is as good as that of the male ducks, which will remain to be demonstrated in future studies.

Evaluation of Aloe Vera Gel Combined with Cinnamon Oil with Antibacterial Activity for Wound Healing Application

Treatment of chronic wounds has been shifted to traditional approaches due to surge in antibiotic resistance. Wounds that fail to heal satisfactorily may result in the amputation of the organ. In this research work, cinnamon oil (CO) and aloe vera (AV) that have been traditionally used as antibacterial agents are combined in a unique gel (COVA) and its antibacterial activity has been evaluated through in vitro and in vivo studies. Antibacterial activity was measured through disk diffusion and agar dilution method against Pseudomonas aeruginosa and Staphylococcus aureus. To check antibacterial and wound healing activity, diabetic excision wound healing rat model was used. Wound closure, wound contraction, tissue hydroxyproline content, antioxidant capacity (TAC), and malondialdehyde (MDA) level were monitored. The minimum inhibitory concentrations of CO + AV for bacterium P. aeruginosa and S. aureus were 100 and 200 µg/ml, respectively. After 14 days, the wounds covered with COVA therapy reached to nearly full wound closure (79% wound contraction) compared to control. The collagen content and level of TAC increased significantly (P < 0.05) in treated groups; therefore, 25% fast healing was observed in wounds treated with CO and AV gel combined. Reduced levels of tissue MDA were observed in all treated groups and specially wound covered with COVA (0.43 mM/mg in control vs 0.25 mM/mg in COVA). Histopathological examination also supported the outcomes. Significantly elevated increase in the level of hydroxyproline was found in rats of COVA treatment group (37.1 ± 0.44). Combination of CO and AV can be potentially used to prevent infection in wound; as these herbal agents not only inhibit the growth of pathogenic bacteria but also accelerate tissue repair.

Collagen/polyester-polyurethane porous scaffolds for use in meniscal repair

Focusing on the regeneration of damaged knee meniscus, we propose a hybrid scaffold made of poly(ester-urethane) (PEU) and collagen that combines suitable mechanical properties with enhanced biological integration. To ensure biocompatibility and degradability, the degradable PEU was prepared from a poly(ε-caprolactone), L-lysine diisocyanate prepolymer (PCL di-NCO) and poly(lactic-co-glycolic acid) diol (PLGA). The resulting PEU (Mn = 52 000 g mol-1) was used to prepare porous scaffolds using the solvent casting (SC)/particle leaching (PL) method at an optimized salt/PEU weight ratio of 5 : 1. The morphology, pore size and porosity of the scaffolds were evaluated by SEM showing interconnected pores with a uniform size of around 170 μm. Mechanical properties were found to be close to those of the human meniscus (Ey ∼ 0.6 MPa at 37 °C). To enhance the biological properties, incorporation of collagen type 1 (Col) was then performed via soaking, injection or forced infiltration. The latter yielded the best results as shown by SEM-EDX and X-ray tomography analyses that confirmed the morphology and highlighted the efficient pore Col-coating with an average of 0.3 wt% Col in the scaffolds. Finally, in vitro L929 cell assays confirmed higher cell proliferation and an improved cellular affinity towards the proposed scaffolds compared to culture plates and a gold standard commercial meniscal implant.

Elucidation of the Role of TRPV1, VEGF-A, TXA2, Redox Homeostasis, and Inflammatory Cascades in Protection against Cold Injuries by Herbosomal-Loaded PEG-Poloxamer Topical Formulation

High-altitude regions, cold deserts, permafrost regions, and the polar region have some of the severest cold conditions on earth and pose immense perils of cold injuries to exposed individuals. Accidental and unintended exposures to severe cold, either unintentionally or due to occupational risks, can greatly increase the risk of serious conditions including hypothermia, trench foot, and cold injuries like frostbite. Cold-induced vasoconstriction and intracellular/intravascular ice crystal formation lead to hypoxic conditions at the cellular level. The condition is exacerbated in individuals having inadequate and proper covering and layering, particularly when large area of the body are exposed to extremely cold environments. There is a paucity of preventive and therapeutic pharmacological modalities that have been explored for managing and treating cold injuries. Given this, an efficient modality that can potentiate the healing of frostbite was investigated by studying various complex pathophysiological changes that occur during severe cold injuries. In the current research, we report the effectiveness and healing properties of a standardized formulation, i.e., a herbosomal-loaded PEG-poloxamer topical formulation (n-HPTF), on frostbite. The intricate mechanistic pathways modulated by the novel formulation have been elucidated by studying the pathophysiological sequelae that occur following severe cold exposures leading to frostbite. The results indicate that n-HPTF ameliorates the outcome of frostbite, as it activates positive sensory nerves widely distributed in the epidermis transient receptor potential vanilloid 1 (TRPV1), significantly (p < 0.05) upregulates cytokeratin-14, promotes angiogenesis (VEGF-A), prominently represses the expression of thromboxane formation (TXA2), and significantly (p < 0.05) restores levels of enzymatic (glutathione reductase, superoxide dismutase, and catalase) and nonenzymatic antioxidants (glutathione). Additionally, n-HPTF attenuates oxidative stress and the expression of inflammatory proteins PGF-2α, NFκB-p65, TNF-α, IL-6, IL-1β, malondialdehyde (MDA), advanced oxidative protein products (AOPP), and protein carbonylation (PCO). Masson's Trichrome staining showed that n-HPTF stimulates cellular proliferation, and increases collagen fiber deposition, which significantly (p < 0.05) promotes the healing of frostbitten tissue, as compared to control. We conclude that protection against severe cold injuries by n-HPTF is mediated via modulation of pathways involving TRPV1, VEGF-A, TXA2, redox homeostasis, and inflammatory cascades. The study is likely to have widespread implications for the prophylaxis and management of moderate-to-severe frostbite conditions.

Ninety Sixth-Hour Impact of Scalding Burns on End Organ Damage, Systemic Oxidative Stress, and Wound Healing in Rats Treated With Three Different Types of Dressings

In this study, we investigated the effects of 3 different burn dressing treatments, including experimental, silver, and modern dressing materials, on systemic oxidative stress in rats with severe scald burns within the first 96 h. The rats were divided into five groups: a burn group (n = 10), a polylactic membrane group (n = 10), a silver sulfadiazine group (n = 10), a curcumin group (n = 10), and a control group (n = 10), consisting of equal numbers of female and male rats. In the first 4 groups, 30% of the rats' total body surface area was scalded at 95°C. The burn group was not treated. Each group was treated with group-name dressing material. The control group was neither treated nor burned. The rats were sacrificed, and blood and tissue samples were obtained at the 96th hour when severe effects of oxidative stress developed postburns. Systemic inflammatory biomarkers and oxidative stress parameters were examined. In addition, apoptosis and organ damage in liver, kidney, lung, and skin tissues were evaluated biochemically and histopathologically. When the parameters were statistically analyzed, we found that the systemic levels of oxidative stress and inflammatory damage to liver, kidney, and lung tissues were lower in the 3 treated groups than in the burn group. We believe that the dressing material's efficacy in the treatment of severe burns may be dependent on its ability to combat oxidative stress and inflammation.

Investigation of the effects of white tea on liver fibrosis: An experimental animal model

Liver fibrosis is a common, progressive disease that affects millions of patients worldwide. In this study, it was aimed at investigating the effect of white tea on liver fibrosis in an in-vivo environment by creating an experimental liver fibrosis model on rats. In this study, an experimental liver fibrosis model was created with carbon tetrachloride (CCl4) in Sprague-Dawley rats to investigate the effect of white tea on liver fibrosis. Rats are treated with CCl4 (1 mL/kg) to constitute the liver fibrosis model. White tea was given ad libitum with drinking water. As a result of the study, liver tissue hydroxyproline levels were found to be significantly lower (p = .001) in the white tea group. Histopathologically, it was found that the liver tissue histopathological damage score (LHDS) and fibrosis scoring were significantly lower (p < .001) in the white tea group. However, although it was not statistically significant in the group given white tea, compared with the fibrosis group, it was found that the malondialdehyde (MDA) level in the liver tissues was lower, the glutathione (GSH) level was higher, and the serum alanine aminotransferase (ALT) levels were lower. The study explained the effect of white tea on liver fibrosis and suggested that white tea might be beneficial in reducing the progression of liver fibrosis.

Preliminary evaluation of fish cartilage as a promising biomaterial in cartilage tissue engineering

Fish cartilage is known as a valuable source of natural biomaterials due to its unique composition and properties. It contains a variety of bioactive components that contribute to its potential applications in different domains such as tissue engineering. The present work aimed to consider the properties of backbone cartilage from fish with a cartilaginous skeleton, including elasmobranch (reticulate whipray: Himantura uarnak and milk shark: Rhizoprionodon acutus) and sturgeon (beluga: Huso huso). The histomorphometric findings showed that the number of chondrocytes was significantly higher in reticulate whipray and milk shark compared to beluga (p < 0.05). The highest GAGs content was recorded in reticulate whipray cartilage compared to the other two species (p < 0.05). The cartilage from reticulate whipray and beluga showed higher collagen content than milk shark cartilage (p < 0.05), and the immunohistochemical assay for type II collagen (Col II) showed higher amounts of this component in reticulate whipray compared to the other two species. Young's modulus of the cartilage from reticulate whipray was significantly higher than that of milk shark and beluga (p < 0.05), while no significant difference was recorded between Young's modulus of the cartilage from milk shark and beluga. The gene expression of ACAN, Col II, and Sox9 showed that the cartilage-ECM from three species was able to induce chondrocyte differentiation from human adipose tissue-derived stem cells (hASCs). From these results, it can be concluded that the cartilage from three species, especially reticulate whipray, enjoys the appropriate biological properties and provides a basis for promoting its applications in the field of cartilage tissue engineering.

Structural and mechanical behavior of type-I collagen fibrils in presence of induced electrostatic interactions through ionic liquids

Tuning the self-assembly of collagen has broad applications in the biomedical field owing to their desired biological performance as collagenous materials with tunable functionalities can further determine cellular responses. In this work, an attempt has been made to tune the self-assembly of collagen using ionic liquids, viz., imidazolium chloride (IC) and choline dihydrogen phosphate (CDHP) at its physiological pH, followed by probing assembled systems using various characterization methods. Turbidity measurements of fibrillar networks were performed to ascertain the rate of fibril formation in addition of imidazolium chloride and choline dihydrogen phosphate to collagen at physiological pH. Morphological changes were examined using Scanning Electron Microscope (SEM), binding affinities were measured by Microscale Thermophoresis (MST), in addition to, changes in the shear viscosity, mechanical strength of collagen fibrils when interacted with imidazolium and choline based ILs were carried out using rotational rheometer and Quartz Crystal Microbalance (QCM) measurements. Experimental result depicts that CDHP imparts better crosslinking as well as mechanical strength compare to IC, which is already known for destabilizing the triple helix structure is inhibiting the fibril formation. This self-assembled, ionic-liquid treated collagen-fibrillar system would accelerate various force modulated fibrillar network study, for mimicking the ECM and tissue engineering application.

The Potential of Twendee X® as a Safe Antioxidant Treatment for Systemic Sclerosis

Systemic sclerosis (SSc) is an autoimmune disease characterized by systemic skin hardening, which combines Raynaud's phenomenon and other vascular disorders, skin and internal organ fibrosis, immune disorders, and a variety of other abnormalities. Symptoms vary widely among individuals, and personalized treatment is sought for each patient. Since there is no fundamental cure for SSc, it is designated as an intractable disease with patients receiving government subsidies for medical expenses in Japan. Oxidative stress (OS) has been reported to play an important role in the cause and symptoms of SSc. HOCl-induced SSc mouse models are known to exhibit skin and visceral fibrosis, vascular damage, and autoimmune-like symptoms observed in human SSc. The antioxidant combination Twendee X® (TwX) is a dietary supplement consisting of vitamins, amino acids, and CoQ10. TwX has been proven to prevent dementia in humans with mild cognitive impairment and significantly improve cognitive impairment in an Alzheimer's disease mouse model by regulating OS through a strong antioxidant capacity that cannot be achieved with a single antioxidant ingredient. We evaluated the effectiveness of TwX on various symptoms of HOCl-induced SSc mice. TwX-treated HOCl-induced SSc mice showed significantly reduced lung and skin fibrosis compared to untreated HOCl-induced SSc mice. TwX also significantly reduced highly oxidized protein products (AOPP) in serum and suppressed Col-1 gene expression and activation of B cells involved in autoimmunity. These findings suggest that TwX has the potential to be a new antioxidant treatment for SSc without side effects.

Assessment of wound healing activity in diabetic mice treated with a novel therapeutic combination of selenium nanoparticles and platelets rich plasma

Diabetic wound healing is sluggish, often ending in amputations. This study tested a novel, two-punch therapy in mice-Selenium nanoparticles (Se NPs) and platelet-rich plasma (PRP)-to boost healing. First, a mouse model of diabetes was created. Then, Se NPs were crafted for their impressive antioxidant and antimicrobial powers. PRP, packed with growth factors, was extracted from the mice's blood. Wound healing was tracked for 28 days through photos, scoring tools, and tissue analysis. Se NPs alone spurred healing, and PRP added extra fuel. Furthermore, when used in combination with PRP, the healing process was accelerated due to the higher concentration of growth factors in PRP. Notably, the combination of Se NPs and PRP exhibited a synergistic effect, significantly enhancing wound healing in diabetic mice. These findings hold promise for the treatment of diabetic wounds and have the potential to reduce the need for lower limb amputations associated with diabetic foot ulcers. The innovative combination therapy using Se NPs and PRP shows great potential in expediting the healing process and addressing the challenges of impaired wound healing in individuals with diabetes. This exciting finding suggests this therapy could change diabetic wound management, potentially saving limbs and improving lives.

S100A4-neutralizing monoclonal antibody 6B12 counteracts the established experimental skin fibrosis induced by bleomycin

OBJECTIVES

Our previous studies have demonstrated that the Damage Associated Molecular Pattern (DAMP) protein, S100A4, is overexpressed in the involved skin and peripheral blood of patients with SSc. It is associated with skin and lung involvement, and disease activity. By contrast, lack of S100A4 prevented the development of experimental dermal fibrosis. Herein we aimed to evaluate the effect of murine anti-S100A4 mAb 6B12 in the treatment of preestablished experimental dermal fibrosis.

METHODS

The effects of 6B12 were assessed at therapeutic dosages in a modified bleomycin-induced dermal fibrosis mouse model by evaluating fibrotic (dermal thickness, proliferation of myofibroblasts, hydroxyproline content, phosphorylated Smad3-positive cell count) and inflammatory (leukocytes infiltrating the lesional skin, systemic levels of selected cytokines and chemokines) outcomes, and transcriptional profiling (RNA sequencing).

RESULTS

Treatment with 7.5 mg/kg 6B12 attenuated and might even reduce pre-existing dermal fibrosis induced by bleomycin as evidenced by reduction in dermal thickness, myofibroblast count and collagen content. These antifibrotic effects were mediated by the downregulation of TGF-β/Smad signalling and partially by reducing the number of leukocytes infiltrating the lesional skin and decrease in the systemic levels of IL-1α, eotaxin, CCL2 and CCL5. Moreover, transcriptional profiling demonstrated that 7.5 mg/kg 6B12 also modulated several profibrotic and proinflammatory processes relevant to the pathogenesis of SSc.

CONCLUSION

Targeting S100A4 by the 6B12 mAb demonstrated potent antifibrotic and anti-inflammatory effects on bleomycin-induced dermal fibrosis and provided further evidence for the vital role of S100A4 in the pathophysiology of SSc.

Ac-SDKP attenuates ER stress-stimulated collagen production in cardiac fibroblasts by inhibiting CHOP-mediated NF-κB expression

Inflammation and cardiac fibrosis are prevalent pathophysiologic conditions associated with hypertension, cardiac remodeling, and heart failure. Endoplasmic reticulum (ER) stress triggers the cells to activate unfolded protein responses (UPRs) and upregulate the ER stress chaperon, enzymes, and downstream transcription factors to restore normal ER function. The mechanisms that link ER stress-induced UPRs upregulation and NF-κB activation that results in cardiac inflammation and collagen production remain elusive. N-Acetyl-Ser-Asp-Lys-Pro (Ac-SDKP), a natural tetrapeptide that negatively regulates inflammation and fibrosis, has been reported. Whether it can inhibit ER stress-induced collagen production in cardiac fibroblasts remains unclear. Thus, we hypothesized that Ac-SDKP attenuates ER stress-stimulated collagen production in cardiac fibroblasts by inhibiting CHOP-mediated NF-κB expression. We aimed to study whether Ac-SDKP inhibits tunicamycin (TM)-induced ER stress signaling, NF-κB signaling, the release of inflammatory cytokine interleukin-6, and collagen production in human cardiac fibroblasts (HCFs). HCFs were pre-treated with Ac-SDKP (10 nM) and then stimulated with TM (0.25 μg/mL). We found that Ac-SDKP inhibits TM-induced collagen production by attenuating ER stress-induced UPRs upregulation and CHOP/NF-κB transcriptional signaling pathways. CHOP deletion by specific shRNA maintains the inhibitory effect of Ac-SDKP on NF-κB and type-1 collagen (Col-1) expression at both protein and mRNA levels. Attenuating ER stress-induced UPR sensor signaling by Ac-SDKP seems a promising therapeutic strategy to combat detrimental cardiac inflammation and fibrosis.

Non-enzymatic glycation reduces glucose transport in the human cartilage endplate independently of matrix porosity or proteoglycan content

Background

Intervertebral disc degeneration is associated with low back pain, which is a leading cause of disability. While the precise causes of disc degeneration are unknown, inadequate nutrient and metabolite transport through the cartilage endplate (CEP) may be one important factor. Prior work shows that CEP transport properties depend on the porosity of the CEP matrix, but little is known about the role of CEP characteristics that could influence transport properties independently from porosity. Here, we show that CEP transport properties depend on the extent of non-enzymatic glycation of the CEP matrix.

Methods and Results

Using in vitro ribosylation to induce non-enzymatic glycation and promote the formation of advanced glycation end products, we found that ribosylation reduced glucose partition coefficients in human cadaveric lumbar CEP tissues by 10.7%, on average, compared with donor- and site-matched CEP tissues that did not undergo ribosylation (p = 0.04). These reductions in glucose uptake were observed in the absence of differences in CEP porosity (p = 0.89) or in the amounts of sulfated glycosaminoglycans (sGAGs, p = 0.47) or collagen (p = 0.61). To investigate whether ribosylation altered electrostatic interactions between fixed charges on the sGAG molecules and the mobile free ions, we measured the charge density in the CEP matrix using equilibrium partitioning of a cationic contrast agent using micro-computed tomography. After contrast enhancement, mean X-ray attenuation was 11.9% lower in the CEP tissues that had undergone ribosylation (p = 0.02), implying the CEP matrix was less negatively charged.

Conclusions

Taken together, these findings indicate that non-enzymatic glycation negatively impacts glucose transport in the CEP independent of matrix porosity or sGAG content and that the effects may be mediated by alterations to matrix charge density.

Inulin-like polysaccharide ABWW may impede CCl4 induced hepatic stellate cell activation through mediating the FAK/PI3K/AKT signaling pathway in vitro & in vivo

Studies have shown that terrestrial acidic polysaccharides containing carboxyl groups and seaweed sulfated polysaccharides have strong potential in anti-liver fibrosis. However, there is no investigation on the anti-liver fibrosis of fructan, a ubiquitous natural polysaccharide. The present study aimed to understand the effect of fructan in ameliorating carbon tetrachloride (CCl4)-induced liver fibrosis in mice. Here, an inulin-like fructan ABWW from Achyranthes bidentata Bl. was characterized by fructose enzymatic hydrolysis, methylation analysis, ESI-MS, and NMR. It was composed of →2)-β-d-Fruf-(1→ and →2)-β-d-Fruf-(1, 6→, terminated with →1)-α-d-Glcp and →2)-β-d-Fruf residues. The biological studies showed that ABWW could improve liver damage and liver fibrosis induced by CCl4in vivo and inhibit hepatic stellate cell (HSC) activation and migration in vitro. We further demonstrated that ABWW inhibited LX2 activation via suppressing the FAK/PI3K/AKT signaling pathway. Hence, ABWW might be a potential novel active compound for anti-fibrosis new drug development.

Fabrication of bioinspired keratin/sodium alginate based biopolymeric mat loaded with herbal drug and green synthesized zinc oxide nanoparticles as a dual drug antimicrobial wound dressing

Dual drug antibacterial wound dressings with biological materials possess crucial wound healing characteristics including biocompatibility, non-toxicity, degradability, mechanical strength and antibacterial properties. The study focusses on fabricating keratin (K)‑sodium alginate (A) based wound dressings by loading green synthesized zinc oxide nanoparticles (ZnO NPs) using C. roseus (leaf extract) and M. recutita (Chamomile flower part) herbal drug (CH) as a bioactive dual antibacterial wound dressing for the first time. The optimized ZnO NPs and CH exhibits strong physiochemical and electrostatic interactions (FT-IR, XRD and SEM) on the fabricated K-A-CH-ZnO biopolymeric mats. Moreover, the tiny porous network of the biopolymeric mat enhances thermal stability, hydrophilicity, mechanical strength and explores the water vapor transmission (2538.07 g/m2/day) and oxygen permeability (7.38 ± 0.31 g/m2) to maintain moist environment and cell-material interactions. During enzymatic degradation studies, ZnO NPs and CH of biopolymeric mat not only retains structural integrity but also increases the characteristic of swelling with sustained drug release (57 %) in 144 h which accelerates wound healing process. Also, K-A-CH-ZnO mat exhibited excellent antibacterial effects against B. subtilis and E. coli. Furthermore, NIH 3T3 fibroblast cell behavior using MTT assay and in vivo evaluations of biopolymeric mat depicted enhanced biocompatibility with increased collagen deposition at the wound site as a prominent dual drug medicated antimicrobial wound dressing.

Nrf2 activation by hydroxytyrosol and dimethyl fumarate ameliorates skin tissue repair in high-fat diet-fed mice by promoting M2 macrophage polarization and normalizing inflammatory response and oxidative damage

Hydroxytyrosol (HT) or dimethyl fumarate (DMF), activators of nuclear factor erythroid 2-related factor 2 (Nrf2), may reduce obesity in high-fat diet (HFD)-fed animals; nevertheless, the role of these activators on skin tissue repair of HFD-fed animals was not reported. This study investigated whether HT or DMF could improve skin wound healing of HFD-fed obese animals. Mice were fed with an HFD, treated with HT or DMF, and full-thickness skin wounds were created. Macrophages isolated from control and obese animals were treated in vitro with HT. DMF, but not HT, reduced the body weight of HFD-fed mice. Collagen deposition and wound closure were improved by HT or DMF in HFD-fed animals. HT or DMF increased anti-inflammatory macrophage phenotype and protein Nrf2 levels in wounds of HFD-fed mice. Lipid peroxidation and protein tumor necrosis factor-α levels were reduced by HT or DMF in wounds of HFD-fed animals. In in vitro, HT stimulated Nrf2 activation in mouse macrophages isolated from obese animals. In conclusion, HT or DMF improves skin wound healing of HFD-fed mice by reducing oxidative damage and inflammatory response. HT or DMF may be used as a therapeutic strategy to improve the skin healing process in individuals with obesity.

PPARγ partial agonist LPSF/GQ-16 prevents dermal and pulmonary fibrosis in HOCl-induced systemic sclerosis (SSc) and modulates cytokine production in PBMC of SSc patients

Thiazolidinediones (TZD) are synthetic molecules that have a range of biological effects, including antifibrotic and anti-inflammatory, and they may represent a promising therapeutic strategy for systemic sclerosis (SSc). The aim of this study was to investigate the immunomodulatory and antifibrotic properties of LPSF/GQ-16, a TZD derivative, in peripheral blood mononuclear cells (PBMC) from SSc patients and in a murine model of SSc HOCl-induced. The PBMC of 20 SSc patients were stimulated with phytohemagglutinin (PHA) and treated with LPSF/GQ-16 for 48 h, later cytokines in the culture supernatants were quantified by sandwich enzyme-linked immunosorbent assay (ELISA) or cytometric bead array (CBA). Experimental SSc was induced by intradermal injections of hypochlorous acid (HOCl) for 6 weeks. HOCl-induced SSc mice received daily treatment with LPSF/GQ-16 (30 mg/kg) through intraperitoneal injections during the same period. Immunological parameters were evaluated by flow cytometry and ELISA, and dermal and pulmonary fibrosis were evaluated by RT-qPCR, hydroxyproline dosage and histopathological analysis. In PBMC cultures, it was possible to observe that LPSF/GQ-16 modulated the secretion of cytokines IL-2 (p < 0.001), IL-4 (p < 0.001), IL-6 (p < 0.001), IL-17A (p = 0.006), TNF (p < 0.001) and IFN-γ (p < 0.001). In addition, treatment with LPSF/GQ-16 in HOCl-induced SSc mice promoted a significant reduction in dermal thickening (p < 0.001), in the accumulation of collagen in the skin (p < 0.001), down-regulated the expression of fibrosis markers in the skin (Col1a1, α-Sma and Tgfβ1, p < 0.001 for all) and lungs (Il4 and Il13, p < 0.001 for both), as well as reduced activation of CD4 + T cells (p < 0.001), B cells (p < 0.001) and M2 macrophages (p < 0.001). In conclusion, LPSF/GQ-16 showed immunomodulatory and antifibrotic properties, demonstrating the therapeutic potential of this molecule for SSc.

Characterization of an in vitro engineered ligament model

In vivo tendon and ligament research can be limited by the difficultly of obtaining tissue samples that can be biochemically analyzed. In this study, we characterize the most widely used in vitro engineered ligament model. Despite previous works suggesting multiple passages change gene expression in 2D primary tenocytes, we found no relationship between passage number and expression of classical tendon fibroblast markers across different biological donors. When engineered into 3D ligaments, there was an increase in maximal tensile load between 7 and 14 days in culture, that corresponded with an increase in collagen content. By contrast, percent collagen increased logarithmically from Day 7 to Day 14, and this was similar to the increase in the modulus of the tissue. Importantly, there was no relationship between passage number and mechanical function or collagen content in the two independent donors tested. These results suggest that the model develops quickly and is reliable across differing passage numbers. This provides the field with the ability to 1) consistently determine functional changes of interventions out to passage number 10; and 2) to time interventions to the appropriate developmental stage: developing/regenerating (Day 7) or mature (Day 14) tissue.

Modification of bismuth film and poly(L-hydroxyproline) onto a screen-printed graphene electrode: A step towards a non-enzymatic platform for determining L-hydroxyproline in human urine samples

A novel sensing material for L-hydroxyproline (Hyp) detection was developed by synthesizing a bismuth film (BiF) and poly(L-hydroxyproline) (Poly(Hyp)) on a screen-printed graphene electrode (SPGE). Initially, the BiF electrodeposition was produced on the SPGE surface, followed by the Poly(Hyp) electropolymerization, resulting in the obtained Poly(Hyp)/BiF/SPGE. The morphology of a sponge-like thin film of Poly(Hyp)/BiF on SPGE had uniform nanometer-sized cavities on the graphene surface, offering a large electroactive area for interaction with the target substance. Cyclic and differential pulse voltammetry was used to examine the sensing performance of the proposed sensor, which revealed that the Poly(Hyp)/BiF/SPGE had the highest response toward Hyp detection. This was attributed to BiF and Poly(Hyp) can facilitate the transfer of electrons at an electrode/solution interface, resulting in an effective sensor for the detection of Hyp. Under the optimal conditions, the quantification of the proposed sensor was found to be linearly related to Hyp concentrations in the range of 0.01-5.0 mM with a limit of detection of 9.2 μM. Moreover, the interference of other substances detected in biological fluids showed no effect based on the ±5% error, indicating good selectivity for Hyp detection. In real applications, the proposed assay successfully analyzed Hyp in human urine samples, yielding satisfactory results with recoveries in the acceptable range of 98%-102%. Therefore, this facilely synthesized approach could be a suitable candidate to obtain a material to fabricate a new sensor for the measurement of Hyp, an important biomarker in the human body.

Impact of SiO2 nanoparticles on the structure and property of type I collagen in three different forms

Silica-based nanoparticles have found application in the development of biocomposites involving reconstituted collagen in tissue engineering and wound healing, and leather modification, specifically targeting collagen fibers. However, a comprehensive investigation into the interaction between collagen-silica nanoparticles and different forms of collagen using biophysical methods remains unexplored. In this study, we examined the interaction between silica (SiO2) nanoparticles and collagen in its fiber, microfibril, and monomer forms through high-resolution scanning electron microscopy, circular dichroism, Fourier-transform infrared spectroscopy, fluorescence analysis, zeta potential measurements, and turbidity assays. Our results reveal that SiO2 nanoparticles exhibited a non-specific attraction towards collagen fibers without disrupting their structural integrity. Interestingly, SiO2 nanoparticles influenced the process of microfibrillation, resulting in heterogeneous fibril diameters while maintaining the natural D-periodicity. This finding is significant, as fibril size variations can impact the properties of collagen composites. Notably, the triple helical structure of collagen in its monomer form remained unaffected in the presence of SiO2 nanoparticles, indicating that the nanoparticles did not disrupt the electrostatic interactions that stabilize the triple helix. Additionally, the increased stability of SiO2 nanoparticles in the presence of collagen confirmed their interaction. These findings provide a promising avenue for the development of SiO2-based nanoparticles to enhance the stability of collagen fibers and control fiber sizes for biomaterial preparation. Moreover, this study advances the potential application of SiO2-based nanoparticles in leather tanning, an emerging field where nanoparticles can play a crucial role.

Production of dehairing protease by Bacillus cereus VITSN04: a model cradle-to-cradle approach for sustainable greener production of leathers

Despite several attempts over decades, process scalability and sustainability remain a challenge to produce an environmental-friendly enzyme to gain industrial attention. In the present study, microbial degradation of chrome shavings (chromium-collagen leather waste) and the resulting collagen hydrolysate for producing the dehairing protease by Bacillus cereus VITSN04 were investigated in a lab-scale fermentor. Scale-up degradation of shavings resulted in higher recovery of collagen hydrolysate (76%) within 72 h compared to shake flasks (68% in 120 h). Earlier achieved medium composition of collagen hydrolysate (12 g L-1) and molasses (15 g L-1) appeared to induce amylase at the high rate, despite the maximal production of protease (203.8 ± 0.18 U mL-1), which was analysed by ANS fluorescence spectroscopy. Optimization of the media containing collagen hydrolysate (12 g L-1) and molasses (5 g L-1) was effective in producing protease (170.6 ± 0.1 U mL-1) and reduced the co-synthesis of amylase (48.2 ± 0.09 U mL-1). The controlled fermentation process by feeding molasses during the exponential growth phase had enhanced the dehairing protease production (∼2.96 fold). The produced protease then partitioned through the biphasic system and showed significant dehairing of goat skins on the pilot scale. Thus, the scalability of the process to produce dehairing enzymes using waste, generated at the site of its use, offers hope for sustainable greener production of leathers.

Local fractal dimension of collagen detects increased spatial complexity in fibrosis

Increase of collagen content and reorganization characterizes fibrosis but quantifying the latter remains challenging. Spatially complex structures are often analyzed via the fractal dimension; however, established methods for calculating this quantity either provide a single dimension for an entire object or a spatially distributed dimension that only considers binary images. These neglect valuable information related to collagen density in images of fibrotic tissue. We sought to develop a fractal analysis that can be applied to 3-dimensional (3D) images of fibrotic tissue. A fractal dimension map for each image was calculated by determining a single fractal dimension for a small area surrounding each image pixel, using fiber thickness as the third dimension. We found that this local fractal dimension increased with age and with progression of fibrosis regardless of collagen content. Our new method of distributed 3D fractal analysis can thus distinguish between changes in collagen content and organization induced by fibrosis.