Fungal mycelia as the source of chitin and polysaccharides and their applications as skin substitutes

Innovative chitin-glucan based material obtained from mycelium of wood decay fungal strains

Fungi are an alternative source to animal-based chitin. In fungi, chitin fibrils are strongly interconnected and bound with glucans that justify the unique matrix. The present study aimed to extract chitin and glucans from the mycelium of several wood decay fungal strains in order to obtain flexible materials and to check correlations between chitin content and the mechanical properties of these materials. Five strains were chosen in consideration of their different cell wall chemical composition (high content of α-glucans, β-glucans or chitin) to evaluate how these differences could influence the mechanical and chemical characteristics of the material. The fungal strains were cultivated in liquid-submerged dynamic fermentation (both flasks and bioreactor). Chitin and glucans were crosslinked with acetic acid and plasticized with glycerol to obtain flexible sheets. Abortiporus biennis, Fomitopsis iberica and Stereum hirsutum strains were found to adapt to produce material with adequate flexibility. The obtained materials were characterized by Thermogravimetric analysis (TGA) for the understanding of the material composition. The material obtained from each species was mechanically tested in terms of tear strength, elongation at break, and Young's modulus.

Perspectives of nanofibrous wound dressings based on glucans and galactans - A review

Wound healing is a complex and dynamic process that needs an appropriate environment to overcome infection and inflammation to progress well. Wounds lead to morbidity, mortality, and a significant economic burden, often due to the non-availability of suitable treatments. Hence, this field has lured the attention of researchers and pharmaceutical industries for decades. As a result, the global wound care market is expected to be 27.8 billion USD by 2026 from 19.3 billion USD in 2021, at a compound annual growth rate (CAGR) of 7.6 %. Wound dressings have emerged as an effective treatment to maintain moisture, protect from pathogens, and impede wound healing. However, synthetic polymer-based dressings fail to comprehensively address optimal and quick regeneration requirements. Natural polymers like glucan and galactan-based carbohydrate dressings have received much attention due to their inherent biocompatibility, biodegradability, inexpensiveness, and natural abundance. Also, nanofibrous mesh supports better proliferation and migration of fibroblasts because of their large surface area and similarity to the extracellular matrix (ECM). Thus, nanostructured dressings derived from glucans and galactans (i.e., chitosan, agar/agarose, pullulan, curdlan, carrageenan, etc.) can overcome the limitations associated with traditional wound dressings. However, they require further development pertaining to the wireless determination of wound bed status and its clinical assessment. The present review intends to provide insight into such carbohydrate-based nanofibrous dressings and their prospects, along with some clinical case studies.

In Vivo Wound-Healing Effect of Chemical and Green Synthesized Chitosan Nanoparticles Using Lawsonia inermis Ethanolic Extract

Wounds can be a result of surgery, an accident, or other factors. There is still a challenge to find effective topical wound-healing agents. This study aims to investigate the wound-healing activity of chemical and green synthesized chitosan nanoparticles (Ch-NPs) using Lawsonia inermis leaves extract. The nanoparticles were morphologically and chemically characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and high-resolution transmission electron microscopy (HRTEM). Forty-five adult female albino rats were randomly divided into three groups. The cutaneous surgical wounds were topically treated with 0.9% normal saline (control group), green Ch-NPs (second group), and chemical Ch-NPs gels (third group), respectively. The clinical picture of wounds and histopathological changes were assessed on the 3rd, 7th, 14th, and 21st days post-treatment. X-ray diffraction analysis revealed great crystallinity and purity of nanoparticles. The studied nanoparticles increased the wound contraction percent (WC%), reduced healing time and wound surface area (WSA), and these results were backed up by histological findings that indicated improved epithelialization, dermal differentiation, collagen deposition, and angiogenesis in treated rats compared with control rats (p < 0.05). We concluded that the wound-healing effects of the studied nanoparticles are encouraging, and further studies for complete assessment are still needed.

Preparation and characterization of chondroitin sulfate from large hybrid sturgeon cartilage by hot-pressure and its effects on acceleration of wound healing

In this paper, a combination of hot-pressure, enzymatic hydrolysis and membrane separation process is used for efficiently and environmentally friendly extraction of chondroitin sulfate (CS) from large hybrid sturgeon cartilage, namely, HPCS. The recovery and yield of CS were 93.68% and 36.47% under the optimized conditions. Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and high-performance liquid chromatography (HPLC) indicated that the HPCS was composed of monosulfated disaccharides in position 6 and 4 of the N-acetyl-D-galactosamine (58.38% and 27.34%, respectively) and nonsulfated disaccharide (14.29%), which was similar to the composition of CS extracted by dilute alkali-enzymatic hydrolysis-chemical precipitation from large hybrid sturgeon cartilage (SCS). The wound healing results indicated that HPCS could promote cell migration and proliferation, alleviate inflammation and facilitate angiogenesis, which results in its excellent wound treatment activity. These results provide theoretical and practical significance for the production and application of chondroitin sulfate.

Fabrication and characterization of Rhizochitosan and its incorporation with platelet concentrates to promote wound healing

Composite dressing composed of Rhizochitosan and Regenplex™ to promote wound healing were assessed. Rhizochitosan was fabricated by deacetylation of Rhizochitin, which obtained by simply depigmenting sporangium-free mycelial mattress produced from Rhizopus stolonifer F6. Physicochemical characterizations of Rhizochitosan demonstrated that it contained 13.5% chitosan with a water-absorption ability of 35-fold dry weight and exhibiting hydrogel nature after hydration. In a wound-healing study on SD rats with full-thickness injury, the composite dressing had a better healing effect than those for each individual components and control group and wound even healed as functional tissue instead of scar tissue. The underlying mechanism of the composite beneficial to wound remodeling is likely attributable to a more reduction level of matrix metalloproteinase (MMP)-9 expression in early stage and a higher MMP-2 expression level in a later stage of healing process. Conclusively, the composite dressing demonstrated to be highly beneficial to the healing of full-thickness injury wound.

Purification and Characterization of Antibacterial Activity against Phytopathogenic Bacteria in Culture Fluids from Ganoderma lucidum

Previous studies of Ganoderma lucidum have focused on its medicinal applications. Limited information is available about its antibacterial activity against plant pathogens. Thus, the goal of this study was to purify and characterize the antibacterial activity against plant pathogenic bacteria from culture fluids of G. lucidum. The nature of the bioactive components was determined using heat boiling, organic solvents, dialysis tubing, gel exclusion chromatography (GEC), proteinase sensitivity, HPLC, HPLC-APCI-MS, and GC-MS. The bioactive compounds were neither lipid, based on their solubility, nor proteic in nature, based on proteinase digestion and heat stability. The putative-bioactive polysaccharides have molecular weights that range from 3500 to 4500 Daltons as determined by dialysis tubing, GEC and APCI-MS analysis. The composition of the antibacterial compounds was determined by GC-MS. This is the first report of small polysaccharides produced by G. lucidum with activity against bacterial plant pathogens.

Towards fungal sensing skin

A fungal skin is a thin flexible sheet of a living homogeneous mycelium made by a filamentous fungus. The skin could be used in future living architectures of adaptive buildings and as a sensing living skin for soft self-growing/adaptive robots. In experimental laboratory studies we demonstrate that the fungal skin is capable for recognising mechanical and optical stimulation. The skin reacts differently to loading of a weight, removal of the weight, and switching illumination on and off. These are the first experimental evidences that fungal materials can be used not only as mechanical 'skeletons' in architecture and robotics but also as intelligent skins capable for recognition of external stimuli and sensorial fusion.

Acetobacter Biofilm: Electronic Characterization and Reactive Transduction of Pressure

The bacterial skin studied here is a several centimeter-wide colony of Acetobacter aceti living on a cellulose-based hydrogel. We demonstrate that the colony exhibits trains of spikes of extracellular electrical potential, with amplitudes of the spikes varying from 1 to 17 mV. The bacterial pad responds to mechanical stimulation with distinctive changes in its electrical activity. While studying the passive electrical properties of the bacterial pad, we found that the pad provides an open-circuit voltage drop (between 7 and 25 mV) and a small short-circuit current (1.5-4 nA). We also observed by pulsed tomography and spatially resolved impedance spectroscopy that the conduction occurs along preferential paths, with the peculiar side-effect of having a higher resistance between closer electrodes. We speculate that the Acetobacter biofilms could be utilized in the development of living skin for soft robots: such skin will act as an electrochemical battery and a reactive tactile sensor. It could even be used for wearable devices.

Fungal sensing skin

BACKGROUND

A fungal skin is a thin flexible sheet of a living homogeneous mycelium made by a filamentous fungus. The skin could be used in future living architectures of adaptive buildings and as a sensing living skin for soft self-growing/adaptive robots.

RESULTS

In experimental laboratory studies we demonstrate that the fungal skin is capable for recognising mechanical and optical stimulation. The skin reacts differently to loading of a weight, removal of the weight, and switching illumination on and off.

CONCLUSION

These are the first experimental evidences that fungal materials can be used not only as mechanical 'skeletons' in architecture and robotics but also as intelligent skins capable for recognition of external stimuli and sensorial fusion.

Enhanced polysaccharide nanofibers via oxidation over SiliaCat TEMPO

Drawing on independent work carried out by academic and industrial researchers using the immobilized TEMPO catalyst SiliaCat TEMPO, in this study we show how shifting the carboxylation process mediated by TEMPO in solution to a process mediated by the above-mentioned hybrid sol-gel catalyst allows the synthesis of insoluble polysaccharide nanofibers of superior quality, eliminating waste. This will dramatically reduce the polysaccharide nanofiber production costs opening the route to large-scale production and uptake of these versatile nanofibers in a variety of functional products where their use has been limited by high cost. The results of this study will be useful for catalysis and biotechnology researchers as well as for chemistry educators teaching green chemistry, nanochemistry, and catalysis using the outcomes of recent research.

One-pot fabrication of sacchachitin for production of TEMPO-oxidized sacchachitin nanofibers (TOSCNFs) utilized as scaffolds to enhance bone regeneration

One-pot fabrication of sacchachitin (SC) for mass-production was developed and optimized by selecting KOH as alkaline agent in depigmentation step and utilizing NaClO₂ as bleaching agent in subsequent step in the same pot. Overall yield of one-pot-fabricated SC was up to 35 %w/w of initial weight with a fibrous texture soft enough for mechanical disintegration into SC nanofibers (SCNFs) and better dispersion for producing TEMPO-oxidized SCNFs (T033SC). Both SCNFs and T033SC could form a 3D gelatinous scaffold into which MC3T3-E1 cells were attracted. Higher calcium-trapping ability of T033SC resulting from a greater extent of carboxylate groups provided an excellent bone regeneration environment that resulted in better outcomes of bone regeneration in a femur defect rat model compared to those with SCNFs possessed fewer carboxylate groups. In conclusion, biomaterial scaffolds based on TEMPO-oxidized SCNFs produced from one-pot fabricated SC showed great potential for bone regeneration due to unique physical and chemical properties.

Micronized sacchachitin promotes satellite cell proliferation through TAK1-JNK-AP-1 signaling pathway predominantly by TLR2 activation

BACKGROUND

Ganoderma sp., such as Ganoderma tsugae (GT), play an important role in traditional Chinese medicine. Ganoderma sp. contains several constituents, including Sacacchin, which has recently drawn attention because it can not only enhance the repair of muscle damage but also strengthen the muscle enforcement. Although Ganoderma sp. have a therapeutic effect for neuromuscular disorders, the underlying mechanism remains unclear. This study investigated the effect and underlying molecular mechanism of micronized sacchachitin (mSC) on satellite cells (SCs), which are known as the muscle stem cells.

METHODS

The myogenic cells, included SCs (Pax7⁺) were isolated from tibialis anterior muscles of a healthy rat and were cultured in growth media with different mSC concentrations. For the evaluation of SC proliferation, these cultivated cells were immunostained with Pax7 and bromodeoxyuridine assessed simultaneously. The molecular signal pathway was further investigated by using Western blotting and signal pathway inhibitors.

RESULTS

Our data revealed that 200 µg/mL mSC had an optimal capability to significantly enhance the SC proliferation. Furthermore, this enhancement of SC proliferation was verified to be involved with activation of TAK1-JNK-AP-1 signaling pathway through TLR2, whose expression on SC surface was confirmed for the first time here.

CONCLUSION

Micronized sacchachitin extracted from GT was capable of promoting the proliferation of SC under a correct concentration.

TEMPO-Oxidized Sacchachitin Nanofibers (TOSCNFs) Combined with Platelet-Rich Plasma (PRP) for Management of Dry Eye Syndrome

Introduction

In this study, the combination of TEMPO-oxidized sacchachitin nanofibers (TOSCNFs) with chitosan-activated platelet-rich plasma (cPRP) was evaluated for remedying dry eye syndrome (DES).

Methods

TOSCNFs, designated T050SC, were generated. T050SC combined with chitosan-activated (cPRP) was formulated as eye drops for application for severe DES. To evaluate the effects of cPRP and TOSCNFs on the repair of corneal injury, in vitro studies were conducted using Statens Seruminstitut rabbit corneal (SIRC) epithelial cells for cell proliferation and cell migration assays, and a severe DES animal model using rabbits was established with benzalkonium chloride (BAC) treatment for the evaluation.

Results

Results showed that the optimal eye formulation contained PRP activated by 350 μg/mL of the low-molecular-weight chitosan group (L3) combined with 300 μg/mL TO50SC (L3+T050SC). In the WST-1 cell-proliferation assay, L3 and L3+TO50SC significantly increased Statens SIRC cell proliferation after 24 hrs of incubation. In the SIRC cell migration assay, the L3+TO50SC group showed a wound-healing efficiency of 89% after 24-hr treatment. After 5 days of treatment, Schirmer’s test results did not simulate the dry eye animal model. Typical cornea appearance and eye fluorescein staining results showed that the L3 group had the best effect on improving cornea haze and epithelial damage.

Conclusion

This study has determined that TOSCNFs effectively promoted the healing effect on severe cases of corneal damage, and also might enhance the clinical application and medical potential of PRP in ophthalmology.

3D Chitin Scaffolds of Marine Demosponge Origin for Biomimetic Mollusk Hemolymph-Associated Biomineralization Ex-Vivo

Structure-based tissue engineering requires large-scale 3D cell/tissue manufacture technologies, to produce biologically active scaffolds. Special attention is currently paid to naturally pre-designed scaffolds found in skeletons of marine sponges, which represent a renewable resource of biomaterials. Here, an innovative approach to the production of mineralized scaffolds of natural origin is proposed. For the first time, a method to obtain calcium carbonate deposition ex vivo, using living mollusks hemolymph and a marine-sponge-derived template, is specifically described. For this purpose, the marine sponge Aplysin aarcheri and the terrestrial snail Cornu aspersum were selected as appropriate 3D chitinous scaffold and as hemolymph donor, respectively. The formation of calcium-based phase on the surface of chitinous matrix after its immersion into hemolymph was confirmed by Alizarin Red staining. A direct role of mollusks hemocytes is proposed in the creation of fine-tuned microenvironment necessary for calcification ex vivo. The X-ray diffraction pattern of the sample showed a high CaCO3 amorphous content. Raman spectroscopy evidenced also a crystalline component, with spectra corresponding to biogenic calcite. This study resulted in the development of a new biomimetic product based on ex vivo synthetized ACC and calcite tightly bound to the surface of 3D sponge chitin structure.

Crab vs. Mushroom: A Review of Crustacean and Fungal Chitin in Wound Treatment

Chitin and its derivative chitosan are popular constituents in wound-treatment technologies due to their nanoscale fibrous morphology and attractive biomedical properties that accelerate healing and reduce scarring. These abundant natural polymers found in arthropod exoskeletons and fungal cell walls affect almost every phase of the healing process, acting as hemostatic and antibacterial agents that also support cell proliferation and attachment. However, key differences exist in the structure, properties, processing, and associated polymers of fungal and arthropod chitin, affecting their respective application to wound treatment. High purity crustacean-derived chitin and chitosan have been widely investigated for wound-treatment applications, with research incorporating chemically modified chitosan derivatives and advanced nanocomposite dressings utilizing biocompatible additives, such as natural polysaccharides, mineral clays, and metal nanoparticles used to achieve excellent mechanical and biomedical properties. Conversely, fungi-derived chitin is covalently decorated with -glucan and has received less research interest despite its mass production potential, simple extraction process, variations in chitin and associated polymer content, and the established healing properties of fungal exopolysaccharides. This review investigates the proven biomedical properties of both fungal- and crustacean-derived chitin and chitosan, their healing mechanisms, and their potential to advance modern wound-treatment methods through further research and practical application.

Nanomaterials Derived from Fungal Sources-Is It the New Hype?

Greener alternatives to synthetic polymers are constantly being investigated and sought after. Chitin is a natural polysaccharide that gives structural support to crustacean shells, insect exoskeletons, and fungal cell walls. Like cellulose, chitin resides in nanosized structural elements that can be isolated as nanofibers and nanocrystals by various top-down approaches, targeted at disintegrating the native construct. Chitin has, however, been largely overshadowed by cellulose when discussing the materials aspects of the nanosized components. This Perspective presents a thorough overview of chitin-related materials research with an analytical focus on nanocomposites and nanopapers. The red line running through the text emphasizes the use of fungal chitin that represents several advantages over the more popular crustacean sources, particularly in terms of nanofiber isolation from the native matrix. In addition, many β-glucans are preserved in chitin upon its isolation from the fungal matrix, enabling new horizons for various engineering solutions.

Wasted Ganoderma tsugae Derived Chitosans for Smear Layer Removal in Endodontic Treatment

The objective of this study is to investigate the synergistic effects of acid etching and metal-ion chelation in dental smear layer removal using wasted Ganoderma tsugae derived chitosans. The wasted Ganoderma tsugae fruiting body was used to prepare both acid-soluble fungal chitosan (FCS) and alkali-soluble polysaccharide (ASP). To explore the effective irrigant concentration for smear layer removal, a chelating effect on ferrous ions was conducted. Specimens of various concentrations of EDTA, citric acid, and polysaccharide solutions were reacted with FerroZine™ then the absorbance was examined at 562 nm by a UV-visible spectrophotometer to calculate their metal chelating capability. Twenty extracted premolars were instrumented and individually soaked in the solutions of 15 wt% EDTA, 10 wt% citric acid, 0.04 wt% ASP, 0.04 wt% FCS, and normal saline were randomly divided into five groups (N=4). Next, each tooth was cleaved longitudinally and examined by scanning electron microscopy (SEM) to assay the effectiveness of smear layer removal. The chelating capability for EDTA, FCS, and ASP showed no significant difference over the concentration of 0.04 wt% (p > 0.05). The SEM results showed that 0.04 wt% FCS solution was effective in smear layer removal along the canal wall. These results indicated that Ganoderma tsuage derived FCS in acid solutions could be a potential alternative as a root canal irrigant solution due to its synergistic effect.

Preparation and characterization of chemically TEMPO-oxidized and mechanically disintegrated sacchachitin nanofibers (SCNF) for enhanced diabetic wound healing

TEMPO-oxidization and mechanical disintegration were utilized to develop sacchachitin nanofibers (SCNF) with a 3D gel structure for being an ideal scaffold. Mechanically disintegrated SCNF (MDSCNF) with NanoLyzer® at 20,000 psi for 5 cycles and TEMPO-oxidized SCNF (TOSCNF) produced with 5.0 and 10.0 mmole NaClO/g SC was designated as SCN5, T050SC, and T100SC, respectively. All 2% MDSCNF suspensions were demonstrated to be in gel form, while all except T100SC of 2% TOSCNF suspensions showed to be wet fiber-like hydrogel. In diabetic wound healing study, both SCN5 and T050SC incorporated in AMPS (2-acrylamide-2-methyl-propane sulfonate)-based wound dressing were showed to accelerate diabetic wound healing forming nearly the same as normal tissues. T050SC/H further provided the healed wound with growth of sweat glands and hair follicles indicating the wound had healed as functional tissue. Conclusively, TEMPO-oxidized SCNF-based hydrogel scaffolds showed greater potentials in tissue regeneration due to its unique physical and chemical properties.

Development and Innovation of Ganoderma Industry and Products in China

Ganoderma (Lingzhi) has been used as a medicinal mushroom to promote health in China for more than 2000 years. The modern research and development of Ganoderma industry started from the 1950s, in which the successful cultivation of Ganoderma fruiting body and submerged fermentation of Ganoderma mycelium lay the critical foundation for the industry development. Recent decades have witnessed the rapid development of Ganoderma industry, which is boosted through various efforts made by the government, the academia, and the industry. In this chapter, the development of Ganoderma industry in China is reviewed in terms of gross output, standards, scientific articles, patents, and associations. In addition, development of Ganoderma products and manufacturing technologies are also overviewed and summarized. In the last section, several innovation trends are suggested for the further development of Ganoderma industry.

Hemostasis and anti-necrotic activity of wound-healing dressing containing chitosan nanoparticles

Necrotic tissues are the dead tissues present in the wounded areas, which need to be removed for rapid wound healing. Various biopolymer-based dressings have been exploited to heal infected wounds, but with limited success. In a quest to develop an effective and economic wound dressing, a biodegradable dressing containing chitosan nanoparticles has been successfully developed. Chitosan nanoparticles were prepared by ionic gelation method and then assembled into the porous chitosan dressing, by lyophilization. The resulting dressing was analyzed for morphology, porosity, pore volume, surface area and biodegradability. Higher surface area and porosity of the dressing facilitated its partial biodegradation by enzymatic action. In vitro cellular investigations with Human Dermal Fibroblasts (HDF) confirmed the safety of the dressing for wound healing applications. Human Thrombin-Antithrombin (TAT) based in vitro ELISA assay, for evaluating the hemostasis activity, illustrated an accelerated hemostasis activity, through higher thrombin generation and stable blood clot formation. The blood in contact with the dressing contained two-fold higher levels of TAT, as compared to that in contact with the TAT standard. Our results suggest the potential of the developed dressing for removing the necrotic tissues and accelerating the hemostasis activity, for efficient and rapid wound healing.

Borrowing From Nature: Biopolymers and Biocomposites as Smart Wound Care Materials

Wound repair is a complex and tightly regulated physiological process, involving the activation of various cell types throughout each subsequent step (homeostasis, inflammation, proliferation, and tissue remodeling). Any impairment within the correct sequence of the healing events could lead to chronic wounds, with potential effects on the patience quality of life, and consequent fallouts on the wound care management. Nature itself can be of inspiration for the development of fully biodegradable materials, presenting enhanced bioactive potentialities, and sustainability. Naturally-derived biopolymers are nowadays considered smart materials. They provide a versatile and tunable platform to design the appropriate extracellular matrix able to support tissue regeneration, while contrasting the onset of adverse events. In the past decades, fabrication of bioactive materials based on natural polymers, either of protein derivation or polysaccharide-based, has been extensively exploited to tackle wound-healing related problematics. However, in today's World the exclusive use of such materials is becoming an urgent challenge, to meet the demand of environmentally sustainable technologies to support our future needs, including applications in the fields of healthcare and wound management. In the following, we will briefly introduce the main physico-chemical and biological properties of some protein-based biopolymers and some naturally-derived polysaccharides. Moreover, we will present some of the recent technological processing and green fabrication approaches of novel composite materials based on these biopolymers, with particular attention on their applications in the skin tissue repair field. Lastly, we will highlight promising future perspectives for the development of a new generation of environmentally-friendly, naturally-derived, smart wound dressings.

Enzymatic degradation of β-1,4-linked N-acetylglucosaminoglucan prepared from Thiothrix nivea

Thiothrix nivea is a filamentous sulfur-oxidizing bacterium commonly found in activated sludge. The filament of this bacterium is covered with a sheath. The sheath is an assemblage of macromolecular glucosaminoglucan (GG), [4)-β-d-GlcN-(1 → 4)-β-d-Glc-(1 → ]_n, modified with an unidentified deoxy-sugar at position 3 of Glc. GG was obtained by dialysis after the partial hydrolysis of the sheath. The GG hydrogel was prepared by drying a GG solution. Then, the hydrogel was N-acetylated to prepare a stable hydrogel of N-acetylglucosaminoglucan (NGG), [4)-β-d-GlcNAc-(1 → 4)-β-d-Glc-(1 → ]_n. The NGG hydrogel was stable in phosphate buffer but was disrupted by lysozyme addition, suggesting that NGG is susceptible to lysozyme degradation and has potential for medical use. The GG solution was N-acetylated to prepare a NGG suspension to confirm enzymatic degradation. The turbidity of the NGG suspension was decreased by lysozyme addition. Sugars released in the reaction mixture were derivatized with 4-aminobenzoic acid ethyl ester (ABEE) followed by HPLC analysis. Two major derivatives were detected, and their concentration was increased in reverse proportion to the turbidity of the reaction mixture. The derivatives were identified as GlcNAc-Glc-GlcNAc-Glc-ABEE and GlcNAc-Glc-ABEE by mass spectrometry. Consequently, NGG was found to be degraded by lysozyme via a mechanism similar to that of chitin degradation.

Chitin and chitosan: biopolymers for wound management

Chitin and chitosan are biopolymers with excellent bioactive properties, such as biodegradability, non-toxicity, biocompatibility, haemostatic activity and antimicrobial activity. A wide variety of biomedical applications for chitin and chitin derivatives have been reported, including wound-healing applications. They are reported to promote rapid dermal regeneration and accelerate wound healing. A number of dressing materials based on chitin and chitosan have been developed for the treatment of wounds. Chitin and chitosan with beneficial intrinsic properties and high potential for wound healing are attractive biopolymers for wound management. This review presents an overview of properties, biomedical applications and the role of these biopolymers in wound care.

Polysaccharide Fabrication Platforms and Biocompatibility Assessment as Candidate Wound Dressing Materials

Wound dressings are critical for wound care because they provide a physical barrier between the injury site and outside environment, preventing further damage or infection. Wound dressings also manage and even encourage the wound healing process for proper recovery. Polysaccharide biopolymers are slowly becoming popular as modern wound dressings materials because they are naturally derived, highly abundant, inexpensive, absorbent, non-toxic and non-immunogenic. Polysaccharide biopolymers have also been processed into biomimetic platforms that offer a bioactive component in wound dressings that aid the healing process. This review primarily focuses on the fabrication and biocompatibility assessment of polysaccharide materials. Specifically, fabrication platforms such as electrospun fibers and hydrogels, their fabrication considerations and popular polysaccharides such as chitosan, alginate, and hyaluronic acid among emerging options such as arabinoxylan are discussed. A survey of biocompatibility and bioactive molecule release studies, leveraging polysaccharide's naturally derived properties, is highlighted in the text, while challenges and future directions for wound dressing development using emerging fabrication techniques such as 3D bioprinting are outlined in the conclusion. This paper aims to encourage further investigation and open up new, disruptive avenues for polysaccharides in wound dressing material development.

Effects of hot-water extracts from Ganoderma lucidum residues and solid-state fermentation residues on prebiotic and immune-stimulatory activities in vitro and the powdered residues used as broiler feed additives in vivo

BACKGROUND

Large amounts of Ganoderma lucidum (GL) commercial products are provided in the worldwide market such as powders, tea bags, or capsules as dietary supplements which contained triterpenoids and/or polysaccharides. Therefore, it was estimated that several thousand tons of GL residues (GLR) are produced and discarded. For recycling uses, the aim of this study was to evaluate the benefits of two hot-water extracts from GLR (HWP_GLR) and solid-state fermentation GLR inoculated with GL mycelia (HWP_GLRF) on the growths of Lactobacillus rhamnosus and Bifidobacterium longum. The RAW264.7 cells were used to investigate the effects of HWP_GLR and HWP_GLRF on nitric oxide productions, phagocytic activities against FITC-labeled E. coli, and to lower lipopolysaccharide (LPS)-binding capacities. The powders of GLR and GLRF were used as additives in the commercial feeds for feeding broiler chicks in vivo to evaluate the immune-stimulatory and prebiotic activities.

RESULTS

HWP_GLR and HWP_GLRF with molecular size 5 to 8 kDa were showed to stimulate growths of L. rhamnosus and B. longum. It was found that in the presence of polymyxin B HWP_GLR and HWP_GLRF could stimulate nitric oxide productions, elevate phagocytic activities against FITC-labeled E. coli, and to lower lipopolysaccharide-binding capacities in RAW264.7 cells. The broiler chicks were selected for feedings in vivo. The 1-day-old chicks were fed commercial feeds for 1 week, and then were fed without or with 4 or 8 % of GLR and GLRF additives for 3 weeks. There was no significant weight difference among feeding groups. However, the phagocytosis and natural killer cytotoxicity in the peripheral bloods, and prebiotic activities of bifidobacteria in feces of GLR and/or GLRF groups were significantly different compared to the control (P < 0.05).

CONCLUSIONS

The GLR, GLRF, and their hot-water extracts with beneficial activities could be processed as feed additives which could increase the waste-recycling.

Effects of a polysaccharide nanogel-crosslinked membrane on wound healing

INTRODUCTION

Wound-dressing materials that promote wound healing while protecting wounds from infections are advantageous for clinical applications. Hence, we developed a cholesterol-bearing pullulan (CHP) nanogel that stimulated wound healing; however, it was mechanically weak and difficult to handle. Thus, the purpose of this study was to examine precisely the effects of a mechanically reinforced nanogel-crosslinked (NanoClik) membrane on wound healing.

MATERIALS AND METHODS

NanoClik was prepared by mixing a thiol-terminated polyethylene glycol solution and an acryloyl group-modified CHP nanogel solution. A thin silicone sheet membrane, which was combined with NanoClik, was prepared. The NanoClick membranes and both positive and negative control membranes (collagen combined with silicone membrane and silicone membrane alone, respectively) were tested in vivo using a dorsal skin defect rat model. The rate and extent of wound healing was compared between groups after 7 and 14 days of implantation.

RESULTS

In the NanoClik membrane group, the wound area was significantly reduced and neoepithelialization was promoted, compared with that observed in the other groups. In addition, extension and accumulation of collagen fibers were evident in the NanoClik membrane group.

CONCLUSION

The NanoClik membrane is a strong candidate for use as an effective and safe wound-dressing material. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 544-550, 2017.

Mycelial Mattress from a Sporangia Formation-Delayed Mutant of Rhizopus stolonifer as Wound Healing-Enhancing Biomaterial

A mycelial mattress of Rhizopus stolonifer obtained from a liquid static culture was utilized for wound dressing and biomedical use. Following screening of mutants induced by UV radiation, F6, exhibiting delayed sporangium formation was selected because its sporangium maturation exhibited a 5-day delay without significant loss of mycelial weight compared to the wild type. The sporangium-free mycelial mattress from the sporangiospore culture of F6 was treated with 1N sodium hydroxide NaOH at 85°C for 2 h to produce a sponge-like membrane named Rhizochitin. The trifluoroacetic acid hydrolysate of Rhizochitin contained 36% N-acetylglucosamine and 53% hexose respectively detected by the Elson-Morgen and phenol-sulfuric acid methods. Results indicated the wound area in rats covered with Rhizochitin was 40% less than that of the uncovered group. Rhizochitin decreased the expression of PDGF in the proliferation stage, increased the expression of TGF-β in the inflammation and proliferation stages, and increased the expression of VEGF in the inflammation and proliferation stages. Rhizochitin inhibited secretion of matrix metalloproteinase-9 on days 1, 7, 9, and 12 and matrix metalloproteinase-2 on days 3, 7, 9, and 12. It was concluded that Rhizochitin has beneficial properties of biocompatible, biodegradable, and wound healing.

Two new triterpenoids from fruiting bodies of fungus Ganoderma lucidum

Two new triterpenoids, (24E)-9α,11α-epoxy-3β-hydroxylanosta-7,24-dien-26-al (1) and (22Z,24Z)-13-hydroxy-3-oxo-14(13 → 12)abeo-lanosta-8,22,24-trien-26,23-olide (2) were isolated from dried fruiting bodies of fungus Ganoderma lucidum. The structures of these two new compounds were elucidated on the basis of extensive spectroscopic analyses. Compound 1 possessed a lanostane skeleton, while compound 2 was based on a rare 14 (13 → 12)abeo-lanostane skeleton with a 26,23-olide moiety. Both of them were evaluated for their antifungal and cytotoxic activities. Neither of them displayed obvious inhibition on Candida albicans and five human cancer cell lines.

Evaluation of biomaterial containing regenerated cellulose and chitosan incorporated with silver nanoparticles

Biomaterials are used in regenerative medicine, implantable materials, controlled release carriers or scaffolds for tissue engineering. In the present study, the composites containing regenerated cellulose (RC) and chitosan (Ch) impregnated with silver nanoparticles (AgNP) with and without antibiotic gentamicin (G) were prepared. The composites prepared were characterized for their physico-chemical and mechanical properties and the results have shown the composite nature. RC-Ch-Ag and RC-Ch-Ag-G composites were used as wound dressing materials in experimental wounds of rats. The healing pattern of the wounds was evaluated by planimetric studies, macroscopic observations, biochemical studies and mechanical properties. The results have shown faster healing pattern in the wounds treated with RC-Ch-Ag and RC-Ch-Ag-G composites compared to untreated control. This study revealed that RC-Ch-Ag composite might be a potential, economical wound dressing material and may be tried on the clinical wounds of animals before being applied on humans.

Role of polymeric biomaterials as wound healing agents

In uncontrolled hemorrhage, the main cause of death on the battlefield and in accidents, half of the deaths are caused by severe blood loss. Polymeric biomaterials have great potential in the control of severe hemorrhage from trauma, which is the second leading cause of death in the civilian community following central nervous system injuries. The intent of this article is to provide a review on currently available biopolymers used as wound dressing agents and to describe their best use as it relates to the condition and type of the wound (acute, chronic, superficial, and full thickness) and the phases of the wound healing process. These biopolymers are beneficial in tissue engineering as scaffolds, hydrogels, and films. Different types of wound dressings based on biopolymers are available in the market, with various physical, chemical, and biological properties. The use of biopolymers as a hemostatic agent depends on its biocompatibility, biodegradability, nonimmunogenicity, and optimal mechanical property. This review summarizes different biopolymers, their physiological characters, and their use as wound healing agents along with biomedical applications.

Dried fruit of the Luffa sponge as a source of chitin for applications as skin substitutes

LUFFACHITIN obtained from the residue of the sponge-like dried fruit of Luffa aegyptiaca was developed as a weavable skin substitute in this study. A chemical analysis revealed that LUFFACHITIN was composed of a copolymer containing N-acetyl-glucosamine (~40%) as a major monomer with a filamentary structure as demonstrated by both optical and scanning electron microscopy. The pulp-like white residue of the sponge-like dried fruit of Luffa aegyptiaca after treatment was then woven into a thin, porous membrane by filtration and lyophilization as a skin substitute for conducting wound-healing study on rats. The results indicated that the LUFFACHITIN membrane showed significant wound-healing enhancement (25 days to complete healing) compared to cotton gauze (>30 days), but not inferior to that of SACCHACHITIN. Furthermore, the LUFFACHITIN membrane had advantages of having a high yield, better physical properties for fabrication, and a more attractive appearance.

Comparison of extraction methods of chitin from Ganoderma lucidum mushroom obtained in submerged culture

The chitin was isolated from the Ganoderma lucidum submerged cultures mycelium as potential source of chitin under biotechnological processes. The extraction of chitin was carried out through 5 different assays which involved mainly three phases: pulverization of the mushroom, deproteinization of the mycelia with NaOH solution, and a process of decolorization with potassium permanganate and oxalic acid. The chitin contents extracted from 9-day mycelia were 413, 339, 87, 78, and 144 mg/g⁻¹ (milligrams of chitin/grams of dry biomass) for A1, A2, A3, A4, and A5, respectively. Obtained chitin was characterized by X-Ray Diffraction (XRD), by Fourier transform infrared spectroscopy (FTIR), and by thermal analysis (TGA). The results showed that Ganoderma lucidum chitin has similar characteristic of chitin from different fonts. The advantage of the biotechnological processes and the fact that Ganoderma lucidum fungus may be used as a potential raw material for chitin production were demonstrated.

Polysaccharides-Rich Extract of Ganoderma lucidum (M.A. Curtis:Fr.) P. Karst Accelerates Wound Healing in Streptozotocin-Induced Diabetic Rats

Ganoderma lucidum (M.A. Curtis:Fr.) P. Karst is a popular medicinal mushroom. Scientific reports had shown that the wound healing effects of G. lucidum were partly attributed to its rich polysaccharides. However, little attention has been paid to its potential effects on wounds associated with diabetes mellitus. In this study, we evaluated the wound healing activity of the hot aqueous extract of G. lucidum in streptozotocin-induced diabetic rats. The extract of G. lucidum was standardised based on chemical contents (w/w) of total polysaccharides (25.1%), ganoderic acid A (0.45%), and adenosine (0.069%). Six groups of six rats were experimentally wounded in the posterior neck region. Intrasite gel was used as a positive control and aqueous cream as the placebo. Topical application with 10% (w/w) of mushroom extract-incorporated aqueous cream was more effective than that with Intrasite gel in terms of wound closure. The antioxidant activity in serum of rats treated with aqueous extract of G. lucidum was significantly higher; whereas the oxidative protein products and lipid damage were lower when compared to those of the controls. These findings strongly support the beneficial effects of standardised aqueous extract of G. lucidum in accelerating wound healing in streptozotocin-induced diabetic rats.

Sacchachitin, a novel chitin-polysaccharide conjugate macromolecule present in Ganoderma lucidum: purification, composition, and properties

CONTEXT

The extraction method and the crude wound healing effects of sacchachitin from Ganoderma tsugae Murr. (Ganodermataceae) has been cited. However, its purity is still largely limited.

OBJECTIVE

An improvement of the fractionation protocol to purify the sacchachitin from Ganoderma lucidum L. (Ganodermataceae) (SGL) is needed.

METHODS

Fruiting bodies were extracted with double distilled water and subsequently the residue treated with 95% ethanol and then 40% ethanol. After being filtered, the pH of the supernatant was adjusted to 4.0 with 1 N HCl and lyophilized. The supernatant was added (3:1 v/v) ethanol, the precipitate was collected, 2% NaOH was added and refluxed. The supernatant was collected with pH adjusted to 4.0, then treated with 10% potassium hydroxide (KOH) with repeating acid precipitation and (3:1) ethanol precipitation twice more to obtain the sacchachitin.

RESULTS

SGL had a hexosamine content 16.3% (w/w), firmly linked to a talomannan. Its Fourier Transform Infrared Spectroscopy (FTIR) spectrum revealed specific absorption (in cm(-1)) ν(O-H) 3455.5 b,s, amide ν(C=O) 1678.5, and amide I° δ(N-H) 1550.4. The percentage deacetylation degree was 37.6 and 39.4% for SGL and MSC, respectively. As contrast, MSC contained only 6.6% of hexosamine with a low protein/carbohydrate ratio 0.35 comparing to 0.82 for SGL. SGL was only moderately strong antioxidant regarding the anti-DPPH, antihydroxyl free radical, and antisuperoxide anion capabilities, exhibiting an IC(33) values of 10 mg/mL (the highest scavenging capability never exceeding 33%), 0.9 mg/mL, and 4.8 mg/mL, respectively.

CONCLUSION

We have successfully isolated the pure sacchachitin from the fruiting bodies of G. lucidum that exhibits potent antioxidative activity and may be useful in fabrication of the artificial skin composite substitute.

ZnO Nanoparticles-Chitosan Composite as Antibacterial Finish for Textiles

The antibacterial performance of sol-gel-derived inorganic-organic hybrid polymers filled with ZnO nanoparticles-chitosan against a gram-negative bacterium Escherichia coli and a gram-positive Micrococcus luteus has been investigated. Three different molecular weights (MW) of chitosan (CTS) 1.36 · 105, 2.2 · 105, and 3.0 · 105 Da with equal degree of deacetylation (DD, 85%) (coded as S 85-60, He 85-250, and He 85-500) with equal degree of deacetylation (DD, 85%) were examined. ZnO was prepared by the base hydrolysis of zinc acetate in isopropanol using lithium hydroxide (LiOH · H2O) to hydrolyze the precursor. Sol-gel-based inorganic-organic hybrid polymers were modified with these oxides and were applied to cellulosic cotton (100%) and cotton/polyester (65/35%) fabrics. Inorganic-organic hybrids polymers were based on 3-glycidyloxypropyltrimethoxysilane (GPTMS). Bacteriological tests were performed in nutrient agar media on solid agar plates and in liquid broth systems using ZnO nanoparticles with average particle size of (40 nm). Our study showed the enhanced antibacterial activity of ZnO nanoparticles chitosan (different MW) of against a gram-negative bacterium Escherichia coli DSMZ 498 and a gram-positive Micrococcus luteus ATCC 9341 in repeated experiments. The antibacterial activity of textile treated with ZnO nanoparticles chitosan increases with decreasing the molecular weight of chitosan.

Wound-healing effect of micronized sacchachitin (mSC) nanogel on corneal epithelium

The extraction residue of the Ganoderma fruiting body, named sacchachitin, has been demonstrated to have the potential to enhance cutaneous wound healing by inducing cell proliferation. In this study, a nanogel formed from micronized sacchachitin (mSC) was investigated for the potential treatment of superficial chemical corneal burns. Reportedly, mSC has been produced successfully and its chemical properties confirmed, and physical and rheological properties characterized. An in vitro cell proliferation study has revealed that at the concentrations of 200, 300, and 400 μg/mL, mSC nanogel significantly increased Statens Seruminstitut rabbit corneal (SIRC) cell proliferation after 24 hours of incubation. In cell migration assay, migration of SIRC cell to wound closure was observed after 24 hours of incubation with the addition of 200 μg/mL mSC of nanogel. In an animal study, acceleration of corneal wound healing was probably due to the inhibition of proteolysis. In conclusion, the findings of this study substantiate the potential application of sacchachitin in the form of mSC nanogel for the treatment of superficial corneal injuries.

Microporous polysaccharide hemospheres and seroma formation after mastectomy and axillary dissection in rats

OBJECTIVE

Seroma is the most common complication after breast surgery. Several methods have been proposed to prevent seroma, but none of these provided a significant effect. A prolonged wound healing process is the most important cause of seroma. Microporous polysaccharide hemospheres (MPH) are used to achieve hemostasis. They may also accelerate wound healing. In this study, the effects of MPH on seroma formation were investigated.

MATERIAL AND METHODS

Female Wistar rats weighing between 200 g and 250 g were used. There were eight rats in each of the control and study groups. Right breast mastectomy and axillary dissection were performed in all rats. While no application was performed after the operation in the control group, MPH was locally applied to the surgical site in the study group. Ten days after the operation, seroma fluid was aspirated and the total volume was recorded. The aspirates were analyzed and tissue samples were obtained from the surgical site.

RESULTS

Seroma was significantly lower in the study group (p=0.001). The mean albumin and lactate dehydrogenase levels were significantly lower in the study group (p=0.003). Pathological examination revealed that increase in fibrous tissue was significantly greater in the control group (p=0.032).

CONCLUSION

MPH may reduce seroma after mastectomy.

A study on a chitosan-gelatin-hyaluronic acid scaffold as artificial skin in vitro and its tissue engineering applications

Chitosan-gelatin-hyaluronic acid scaffolds for tissue regeneration were fabricated by freezing and lyophilizing methods. The scaffolds showed a higher water uptake and retention abilities than chitosan-gelatin scaffolds did. Fibroblasts cultured in chitosan-gelatin-hyaluronic acid scaffolds grew and proliferated well, and they exhibited a strong viability. Keratinocytes were co-cultured with fibroblasts in chitosan-gelatin-hyaluronic acid scaffolds to construct an artificial bilayer skin in vitro. The artificial skin obtained was flexible and had good mechanical properties. The data from this study suggested that chitosan-gelatin-hyaluronic acid scaffolds are suitable for preparing a bilayer skin substitute.

Effect of electrospun non-woven mats of dibutyryl chitin/poly(lactic acid) blends on wound healing in hairless mice

The aim of this study was to examine the proliferative ability of dibutyryl chitin (DBC) on scratch wounds in HaCaT keratinocytes and to evaluate the effect of nanoporous non-woven mat (DBCNFM) on skin wound healing in hairless mice using the advantages of DBCNFM, such as high porosity and high surface area to volume. The cell spreading activity of DBC was verified through a cell spreading assay in scratched human HaCaT keratinocytes. Scratch wound experiments showed that DBC notably accelerates the spreading rate of HaCaT keratinocytes in a dose dependent manner. The molecular aspects of the healing process were also investigated by hematoxylin & eosin staining of the healed skin, displaying the degrees of reepithelialization and immunostaining on extracellular matrix synthesis and remodeling of the skin. Topical application of DBCNFM significantly reduced skin wound rank scores and increased the skin remodeling of the wounded hairless mice in a dose dependent way. Furthermore, DBCNFM notably increased the expression of the type 1 collagen and filaggrin. These results demonstrate that DBC efficiently accelerates the proliferation of HaCaT keratinocytes and DBCNFM notably increases extracellular matrix synthesis on remodeling of the skin, and these materials are a good candidate for further evaluation as an effective wound healing agent.