Hyaluronic Acid: A Powerful Biomolecule with Wide-Ranging Applications-A Comprehensive Review

Enhancing biofabrication: Shrink-resistant collagen-hyaluronan composite hydrogel for tissue engineering and 3D bioprinting applications

Biofabrication represents a promising technique for creating tissues for regeneration or as models for drug testing. Collagen-based hydrogels are widely used as suitable matrix owing to their biocompatibility and tunable mechanical properties. However, one major challenge is that the encapsulated cells interact with the collagen matrix causing construct shrinkage. Here, we present a hydrogel with high shape fidelity, mimicking the major components of the extracellular matrix. We engineered a composite hydrogel comprising gallic acid (GA)-functionalized hyaluronic acid (HA), collagen I, and HA-coated multiwall carbon nanotubes (MWCNT). This hydrogel supports cell encapsulation, exhibits shear-thinning properties enhancing injectability and printability, and importantly significantly mitigates shrinkage when loaded with human fibroblasts compared to collagen I hydrogels (∼20 % vs. > 90 %). 3D-bioprinted rings utilizing human fibroblast-loaded inks maintain their shape over 7 days in culture. Furthermore, inclusion of HAGA into collagen I hydrogels increases mechanical stiffness, radical scavenging capability, and tissue adhesiveness. Notably, the here developed hydrogel is also suitable for human induced pluripotent stem cell-derived cardiomyocytes and allows printing of functional heart ventricles responsive to pharmacological treatment. Cardiomyocytes behave similar in the newly developed hydrogels compared to collagen I, based on survival, sarcomere appearance, and calcium handling. Collectively, we developed a novel material to overcome the challenge of post-fabrication matrix shrinkage conferring high shape fidelity.

Hyaluronic Acid-Based Nanomotors: Crossing Mucosal Barriers to Tackle Antimicrobial Resistance

Bacterial infections pose a significant global health challenge aggravated by the rise of antimicrobial resistance (AMR). Among the obstacles preventing effective treatment are biological barriers (BBs) within the body such as the mucus layer. These BBs trap antimicrobials, necessitating higher doses and ultimately accelerating AMR. Addressing this issue requires innovative therapeutic strategies capable of bypassing BBs to deliver drugs more effectively. Here, we present nanomotors (NMs) based on hyaluronic acid (HA)- and urease-nanogels (NGs) as a solution to navigate effectively in viscous media by catalyzing the decomposition of urea into ammonium and carbon dioxide. These HA-based nanomotors (HA-NMs) were loaded with chloramphenicol (CHL) antibiotic and demonstrated superior antimicrobial activity against Escherichia coli(E. coli) compared to mesoporous silica NMs (MSNP-NMs), a reference in the field of NMs. Moreover, using an in vitro transwell model we evaluated the ability of HA-NMs to penetrate mucin barriers, effectively reducing E. coli proliferation, whereas the free antibiotic did not reduce bacteria proliferation. The optical density reduction at 24 h was over ten times greater than with free CHL. These organic-based enzyme-powered NMs represent a significant advancement in drug delivery, offering a promising approach to combat AMR while addressing the challenges of crossing complex BBs.

Melatonin-loaded nanoparticles protecting human sperm from oxidative stress during cryopreservation

BACKGROUND

During the process of sperm cryopreservation, the overproduction of reactive oxygen species (ROS) triggers oxidative stress thereby leading to a reduction in sperm motility and quality. Therefore, it is a feasible strategy to mitigate oxidative damage during cryopreservation by adding antioxidants to freezing media.

RESEARCH DESIGN AND METHODS

In this study, we explored the potential of melatonin to protect sperm from oxidative stress-induced damage by evaluating sperm-related parameters after thawing through self-assembly with a hyaluronic acid-bilirubin conjugate into nanoparticles (M@HBn).

RESULTS

The optimized M@HBn exhibited uniform spherical morphology with average particle size of 112.57   ±   9.8 nm, PDI of 0.22   ±   0.02, a surface potential of  - 0.43   ±   1.02 mV and entrapment efficiency of 85.1   ±   4.6%. The addition of 5 μM M@HBn demonstrated a notable enhancement in frozen-thawed human spermatozoa viability, motility, and DNA integrity by scavenging ROS. Additionally, the use of M@HBn supplementation in freezing medium resulted in the most mitochondrial stability and total viability as compared to the other groups.

CONCLUSIONS

These findings suggest that M@HBn have the potential to serve as a novel drug delivery platform for protecting spermatozoa against from cryodamage while enhancing the quality of cryopreserved sperm and the bioavailability of melatonin.

Comparative analysis of the therapeutic effects of mesenchymal stem cells and exosomes on cartilage regeneration: exploring their synergistic potential with hyaluronic acid for treating articular cartilage defects

PURPOSE

Articular cartilage exhibits a low regenerative capacity and limited potential for self-renewal. Recent research has demonstrated that exosomes and mesenchymal stem cells (MSCs) significantly enhance cartilage repair by promoting cellular proliferation, increasing extracellular matrix synthesis, and modulating the immune response. Additionally, hyaluronic acid (HA), a critical component of synovial fluid, plays a key role in facilitating cell migration. This study aims to compare the regenerative effects of Wharton's jelly-derived MSCs, MSC-derived exosomes, and their combination with hyaluronic acid in the treatment of cartilage defects. Additionally, we seek to evaluate the impact of hyaluronic acid when combined with MSCs and exosomes through histological analysis in a rat model.

METHODS

In this study, full-thickness cartilage defects were created in the trochlear grooves of both distal femurs in 48 adult rats. The knees were randomly assigned to six groups: Group I: Control-saline, Group II: Wharton's jelly mesenchymal stem cells (MSCs), Group III: Wharton's jelly MSC-derived exosomes (Exo), Group IV: Hyaluronic acid (HA), Group V: MSC and HA combination, and Group VI: Exo and HA combination. Each rat received a total of three intra-articular injections at weekly intervals, beginning two weeks post-surgery. Four weeks following the final injection, all rats were euthanized, and their femurs were dissected for analysis. All groups were assessed macroscopically using the International Cartilage Repair Society (ICRS) scoring system, following histological staining with hematoxylin-eosin (HE) and toluidine blue, and immunohistochemical staining with type II collagen antibodies. The quality of the repaired cartilage was subsequently evaluated according to the ICRS histological grading system by an independent, blinded observer.

RESULTS

Macroscopic evaluations indicated that the ICRS scores of the MSC group (8.2 ± 0.7) were significantly higher (P < 0.05) than those of the control group (4.3 ± 0.7). The cartilage defects in the MSC group showed substantial repair, displaying the most effective cartilage regeneration among all groups. Furthermore, comparison between groups revealed that both the MSC and Exo groups demonstrated a higher rate of defect depth repair, a smaller demarcation border, and a smoother cartilage surface.

CONCLUSIONS

This study demonstrates that exosomes are as effective as stem cell therapies in promoting cartilage repair, suggesting that exosomes may serve as a viable alternative to cell-based therapies for cartilage damage. However, the addition of hyaluronic acid to stem cells and exosomes showed no significant enhancement in cartilage repair. Our findings highlight a potentially effective therapeutic strategy for the treatment of osteochondral cartilage defects.

Hyaluronic Acid and Skin: Its Role in Aging and Wound-Healing Processes

Hyaluronic acid (HA) is a linear, unbranched polysaccharide classified as a glycosaminoglycan. While HA is found in various tissues throughout the body, over half of its total proportion is found in the skin. The role of HA in the skin is complex and multifaceted. HA maintains proper hydration, elasticity, and skin firmness, serving as a key extracellular matrix (ECM) component. With age, HA production gradually decreases, leading to reduced water-binding capacity, drier and less elastic skin, and the formation of wrinkles. Additionally, HA plays an active role in the wound-healing process at every stage. This review summarizes the current background knowledge about the role of HA in skin aging and wound healing. We discuss the latest applications of HA in aging prevention, including anti-aging formulations, nutricosmetics, microneedles, nanoparticles, HA-based fillers, and skin biostimulators. Furthermore, we explore various HA-based dressings used in wound treatment, such as hydrogels, sponges, membranes, and films.

Molecular Mechanisms and Therapeutic Role of Intra-Articular Hyaluronic Acid in Osteoarthritis: A Precision Medicine Perspective

Background: Osteoarthritis (OA) is a degenerative joint disease characterized by progressive cartilage breakdown, synovial inflammation, and pain, which leads to significant disability. IAHA is widely used because of its viscoelastic properties, which restore synovial fluid homeostasis and reduce symptoms. However, emerging evidence suggests that IAHA exerts additional biological effects including chondroprotection, inflammatory modulation, oxidative stress reduction, and pain modulation, which may influence disease progression. Objective: This narrative review examines the biological mechanisms underlying IAHA's role in OA management. The review explored IAHA's effects on synovial fluid viscoelasticity, inflammatory cytokine modulation, cartilage preservation, oxidative stress regulation, and pain pathways, emphasizing the influence of molecular weight variations on therapeutic efficacy. Additionally, this review evaluates IAHA's integration into multimodal treatment strategies, its potential disease-modifying effects, and future directions for personalized treatment approaches. Methods: A comprehensive literature review was conducted using PubMed, Cochrane Library, EMBASE, Scopus, and Web of Science for studies published between January 2000 and March 2024. The search focused on IAHA's molecular, cellular, and biochemical effects in OA and clinical findings assessing its impact on joint function, pain relief, and disease progression. Results: IAHA improves synovial fluid lubrication, reduces proinflammatory cytokines (IL-1β, TNF-α), inhibits matrix metalloproteinases (MMPs), scavenges reactive oxygen species (ROS), and modulates nociceptive pathways. High-molecular-weight IAHA demonstrates superior efficacy in advanced OA, while low-molecular-weight formulations may be better suited for early-stage disease. Although IAHA's symptom relief is comparable to corticosteroids and NSAIDs, its favorable safety profile and emerging disease-modifying potential support its long-term use in OA management. Conclusions: IAHA represents a multifaceted therapeutic approach bridging symptomatic relief and regenerative strategies. While long-term efficacy, optimal administration protocols, and patient-specific responses remain subjects of ongoing research, refining treatment selection criteria, dosing regimens, and combination strategies may enhance clinical outcomes. Future studies should explore biomarker-driven approaches, standardize treatment protocols, and assess IAHA's synergy with regenerative medicine to optimize its role in OA management.

Anatomical Considerations for Hyaluronic Acid Filler Injection for Breast Augmentation in Young Female Patients

BACKGROUND

Hyaluronic acid (HA) fillers offer a minimally invasive alternative for breast augmentation, appealing to young female patients seeking natural results and minimal recovery time. However, achieving optimal outcomes requires a thorough understanding of breast anatomy, filler properties, and safe injection techniques. This study provides a comprehensive analysis of the anatomical considerations, techniques, and filler properties necessary for optimal breast augmentation using HA filler. It also explores patient selection, long-term safety and efficacy, and the management of complications. A review of key anatomical structures, including glandular tissue, fascial layers, vascular anatomy, and Cooper's ligaments was conducted. Injection techniques, such as dual-plane and submuscular approaches, were analysed with a focus on pre-procedural imaging. Four cases of young female patients undergoing breast augmentation using HA filler (e.p.t.q. eve X, Jetema Inc., Seoul, Republic of Korea) were analysed. The efficacy of HA fillers in achieving natural breast enhancement was demonstrated in all four cases. Ultrasound played a crucial role in ensuring accurate filler placement, reducing risks like vascular occlusion and filler migration. Patients reported high satisfaction and minimal complications, though periodic treatments were required for maintenance. HA filler-based breast augmentation is a safe and effective option for young female patients, delivering natural results with rapid recovery. Although the results can be temporary and maintenance treatment is required, HA fillers may offer a non-invasive alternative to silicone implants. Optimal outcomes can be achieved through a thorough understanding of anatomy, the use of highly cohesive fillers, and ultrasound-guided injection techniques.

Membrane drug transporters in cancer: From chemoresistance mechanism to therapeutic strategies

Chemoresistance is a multifactorial phenomenon and the primary cause to the ineffectiveness of oncotherapy and cancer recurrence. Membrane drug transporters are crucial for drug delivery and disposition in cancer cells. Changes in the expression and functionality of these transporters lead to decreased intracellular accumulation and reduced toxicity of antineoplastic drugs. As the mechanism has been better understood and genetic engineering technology progressed quickly in recent years, some novel targeting strategies have come to light. This article summarizes the regulatory mechanisms of membrane drug transporters and provides an extensive review of current approaches to address transporters-mediated chemoresistance. These strategies include the use of chemical inhibitors to block efflux transporters, the development of copper chelators to enhance platinum drug uptake, the delivery of genetic drugs to alter transporter expression, the regulation of transcription and post-translational modifications. Additionally, we provide information of the clinical trial performance of the related targeting strategies, along with the ongoing challenges. Even though some clinical trials failed due to unexpected side effects and limited therapeutic efficacy, the advent of targeting membrane drug transporters still presents a hopeful path for overcoming chemoresistance.

Size-dependent aggregation of erythrocytes by low molecular weight hyaluronic acids of different sizes: bioactivity and quality control potential

Introduction

Hyaluronic acid (HA) is a crucial biological molecule whose diverse functions are strongly influenced by its molecular weight. In particular, low molecular weight HA (LMW-HA) fragments-such as HA60 (average 60 kDa), HA35 (average 35 kDa), and HA24 (average 24 kDa)-exhibit enhanced tissue permeability and unique interactions with cell surfaces compared to high molecular weight HA (HMW-HA). This study investigates the size-dependent aggregation effects of LMW-HA on erythrocytes and examines the implications for bioactivity, quality control, and therapeutic applications.

Methods

We investigated the effects of LMW-HA fragments on erythrocyte aggregation across molecular sizes using erythrocyte sedimentation rate (ESR) assays, CD44 receptor blocking assays, and molecular weight assessment via gel electrophoresis and GPC-MALLS. LMW-HA samples were applied at varying concentrations to measure their binding affinity to erythrocytes, while CD44 antibodies were used to assess receptor involvement. Species-specificity of aggregation was examined by comparing erythrocytes from different animals.

Results

LMW-HA induced erythrocyte aggregation in a size-dependent manner, with HA60 exhibiting the strongest binding affinity, followed by HA35 and HA24. Aggregation was partially reversible and could be inhibited by CD44 antibodies, indicating a receptor-mediated interaction. Minimum effective concentrations for aggregation were inversely related to molecular weight, with lower molecular weight fragments requiring higher concentrations. Species-specific effects were also observed, highlighting variations in erythrocyte-HA interactions across different animals.

Discussion

The study suggests that LMW-HA facilitates erythrocyte aggregation through CD44-mediated binding, offering insights into HA's role in erythrocyte physiology and its effects on blood rheology. The findings support the potential of LMW-HA for therapeutic applications in pain and inflammation management, given its enhanced tissue permeability and reversible interaction with erythrocytes. Additionally, the size-dependent aggregation provides a valuable parameter for quality control, enabling consistency in LMW-HA products. These results underscore the importance of molecular weight in determining HA's physiological and pharmacological activity, paving the way for further clinical research to confirm species-specific effects and optimize safe therapeutic uses of LMW-HA.

In Vivo and Ex Vivo Evaluation of a Novel Method for Topical Delivery of Macromolecules Through the Stratum Corneum for Cosmetic Applications

BACKGROUND

Effective topical delivery of large/charged molecules into skin has always been challenging. Chemical penetration enhancers, organic substances that increase permeability of skin, have been in use for decades with variable success. One application of enhancers involves multilamellar vesicles composed of submicron emulsion droplets and micelles surrounded by concentric phospholipid bilayers.

OBJECTIVE

This report introduces the next generation of multilamellar vesicles, termed Tiered-Release Vesicles (TRVs), as a new platform for topical delivery of macromolecules such as peptides and hyaluronic acid (HA).

METHODS

Fluorescently labeled peptides and HA, diffusion cells, and confocal microscopy were employed to assess the penetration efficiency of macromolecules in TRV formulations using an ex vivo human skin model. Two in vivo studies utilized punch biopsies followed by histochemical staining and analysis.

RESULTS

Based on fluorescent intensity, TRV formulations delivered a large peptide more completely (2-5 fold) into ex vivo human skin than optimized liposomes. The penetration of 2 HA species in TRV formulations was 3- to 13-fold higher than with a simple gel vehicle. In the case studies, reduction of solar elastosis was observed from a topical TRV formulation.

CONCLUSION

Topical delivery of large peptides and HA into human skin using TRV technology has been demonstrated.

Addressing the challenges of infectious bone defects: a review of recent advances in bifunctional biomaterials

Infectious bone defects present a substantial clinical challenge due to the complex interplay between infection control and bone regeneration. These defects often result from trauma, autoimmune diseases, infections, or tumors, requiring a nuanced approach that simultaneously addresses infection and promotes tissue repair. Recent advances in tissue engineering and materials science, particularly in nanomaterials and nano-drug formulations, have led to the development of bifunctional biomaterials with combined osteogenic and antibacterial properties. These materials offer an alternative to traditional bone grafts, minimizing complications such as multiple surgeries, high antibiotic dosages, and lengthy recovery periods. This review examines the repair mechanisms in the infectious microenvironment and highlights various bifunctional biomaterials that foster both anti-infective and osteogenic processes. Emerging design strategies are also discussed to provide a forward-looking perspective on treating infectious bone defects with clinically significant outcomes.

Recent advances of hyaluronic acid-based materials in drug delivery systems and regenerative medicine: A review

Nowadays, diseases have a high rate of incidence and mortality worldwide. On the other side, the drawbacks of conventional modalities in the suppression of diseases have encountered serious problematic issues for the health of human beings. For instance, although various approaches have been applied for the treatment of cancer, it has an ever-increasing rate of incidence and mortality throughout the globe. Thus, there is a fundamental requirement for the development of breakthrough technologies in the inhibition of diseases. Hyaluronic acid (HA) is one of the most practical biopolymers in the suppression of diseases. HA has lots of potential physicochemical (like rheological, structural, molecular weight, and ionization, etc.) and biomedical properties (bioavailability, biocompatibility, CD44 targeting and signaling pathways, components of biological organs, mucoadhesion, immunomodulation, etc.), which made it a potential candidate for the development of breakthrough tools in pharmaceutical and biomedical sciences. The ease of surface modification (carboxylation, amidation, hydroxylation, and esterification), high bioavailability and synthesis routes, and various administration routes are considered as other merits of HA-based vehicles. These mucopolysaccharide HA-based materials have been considerably developed for use in drug delivery systems (DDSs), cancer therapy, wound healing, antiaging, and tissue engineering. This review summarizes the advantages of HA-based DDS and scaffolds in the treatment of diseases.

A Comparative Study between Thiol-Ene and Acrylate Photocrosslinkable Hyaluronic Acid Hydrogel Inks for Digital Light Processing

Photocrosslinkable formulations based on the radical thiol-ene reaction are considered better alternatives than methacrylated counterparts for light-based fabrication processes. This study quantifies differences between thiol-ene and methacrylated crosslinked hydrogels in terms of precursors stability, the control of the crosslinking process, and the resolution of printed features particularized for hyaluronic acid (HA) inks at concentrations relevant for bioprinting. First, the synthesis of HA functionalized with norbornene, allyl ether, or methacrylate groups with the same molecular weight and comparable degrees of functionalization is presented. The thiol-ene hydrogel precursors show storage stability over 15 months, 3.8 times higher than the methacrylated derivative. Photorheology experiments demonstrate up to 4.7-times faster photocrosslinking. Network formation in photoinitiated thiol-ene HA crosslinking allows higher temporal control than in methacrylated HA, which shows long post-illumination hardening. Using digital light processing, 4% w/v HA hydrogels crosslinked with a dithiol allowed printing of 13.5 × 4 × 1 mm3 layers with holes of 100 µm resolution within 2 s. This is the smallest feature size demonstrated in DLP printing with HA-based thiol-ene hydrogels. The results are important to estimate the extent to which the synthetic effort of introducing -ene functions can pay off in the printing step.

Hyaluronic acid modified liposomes with enhanced transdermal delivery of methotrexate for psoriasis treatment

Psoriasis is a chronic inflammatory skin disorder characterized by immune dysregulation and cutaneous symptoms. Methotrexate (MTX), efficacious in psoriasis, suffers from limited transdermal permeability due to its hydrophilic nature. Liposomal nanomedicine, which offers increased bioavailability and targeted delivery with minimized systemic effects, is a promising approach. The application of hyaluronic acid (HA) as a penetration enhancer and modifier leverages its binding to the upregulated CD44 receptor in psoriasis, enhancing the efficacy of liposomes. In this study, we synthesized HA-modified liposomes by conjugating HA with distearoyl phosphatidyl ethanolamine-poly (ethylene glycol) (DSPE-PEG) and encapsulated methotrexate for targeted treatment of psoriasis. The research entailed the meticulous preparation and physicochemical characterization of these HA-modified liposomes, followed by in vitro transdermal delivery assays, cellular uptake studies, and the development of a psoriasis animal model to rigorously assess therapeutic efficacy. Our findings underscore the significant improvement in methotrexate's transdermal penetration and retention within psoriatic lesions afforded by the HA-modified liposomes, indicating a novel and efficacious therapeutic approach for the management of dermatological disorders.

Biochemical Characterization and Mechanism of Thermostability of the Thermophilic Hyaluronate Lyase TcHly8D

Hyaluronate lyases are widely used in medicine and biochemical engineering and are also applied as a tool enzyme to prepare oligosaccharides with various biological activities. To date, only a few hyaluronate lyases are on sale with poor thermostability. In this study, a PL8 hyaluronate lyase, TcHly8D, was found from Thermasporomyces composti and expressed in Escherichia coli with a maximum yield of 1.77 × 109 U/L (3.14 g/L) in a 5-L bioreactor. The recombinant TcHly8D exhibited a high hyaluronate lyase activity of 5.64 × 105 U/mg and an excellent thermostability with half-lives of 184.9 h at 60 °C. Fifty micrograms of TcHly8D could catalyze 5 g of hyaluronic acid with an oligosaccharide yield of 84.8% in 4 h. The salt bridges, hydrogen bonds, and proline residues, but not disulfide bonds, played important roles in the thermostability of TcHly8D. These findings provide insights into the multifunctional application potential of TcHly8D in agriculture, medicine, and the food industry.

Advances in biomaterials-based tissue engineering for regeneration of female reproductive tissues

The anatomical components of the female reproductive system-comprising the ovaries, uterus, cervix, vagina, and fallopian tubes-interact intricately to provide the structural and hormonal support essential for reproduction. However, this system is susceptible to various detrimental factors, both congenital and acquired, that can impair fertility and adversely affect quality of life. Recent advances in bioengineering have led to the development of sophisticated three-dimensional models that mimic the complex architecture and functionality of reproductive organs. These models, incorporating diverse cell types and tissue layers, are crucial for understanding physiological processes within the reproductive tract. They offer insights into decidualization, ovulation, folliculogenesis, and the progression of reproductive cancers, thereby enhancing personalized medical treatments and addressing female infertility. This review highlights the pivotal role of tissue engineering in diagnosing and treating female infertility, emphasizing the importance of considering factors like biocompatibility, biomaterial selection, and mechanical properties in the design of bioengineered systems. The challenge of replicating the functionally specialized and structurally complex organs, such as the uterus and ovary, underscores the need for reliable techniques that improve morphological and functional restoration. Despite substantial progress, the goal of creating a fully artificial female reproductive system is still a challenge. Nonetheless, the recent fabrication of artificial ovaries, uteruses, cervixes, and vaginas marks significant advancements toward this aim. Looking forward, the challenges in bioengineering are expected to spur further innovations in both basic and applied sciences, potentially hastening the clinical adoption of these technologies.

Mechanisms Underlying the Stimulation of DUSP10/MKP5 Expression in Chondrocytes by High Molecular Weight Hyaluronic Acid

Background/Objectives: Previously, we reported that high molecular weight hyaluronic acid (HMW-HA) exerts chondroprotective effects by enhancing dual specificity protein phosphatase 10/mitogen-activated protein kinase (MAPK) phosphatase 5 (DUSP10/MKP5) expression and suppressing inflammatory cytokine-induced matrix metalloproteinase-13 (MMP13) expression in a human immortalized chondrocyte line (C28/I2 cells) via inhibition of MAPKs. The aim of this study was to elucidate the molecular mechanisms underlying the enhancement of DUSP10/MKP5 expression by HMW-HA in C28/I2 cells. Methods: C28/I2 cells were treated with HMW-HA, and the activation of intracellular signaling molecules was determined using Western blot analysis. The expression levels of mRNAs and microRNAs (miRNAs) were evaluated through real-time quantitative reverse transcription PCR analysis. Results: HMW-HA treatment induced Akt phosphorylation via interaction with CD44, and pretreatment with specific inhibitors of phosphatidylinositol-3 kinase/protein kinase B (PI3K/Akt) signaling attenuated the HMW-HA-induced expression of DUSP10/MKP5. HMW-HA suppressed the expression of miR-92a, miR-181a, and miR-181d. Loss-of-function and gain-of-function analyses of these miRNAs indicate that miR-92a, miR-181a, and miR-181d negatively regulate DUSP10/MKP5 expression. Moreover, HMW-HA-induced Akt phosphorylation was partially suppressed by miR-181a and miR-181d mimics. Finally, we found that HMW-HA activates RhoA-associated protein kinase (ROK) signaling, which contributes to Akt phosphorylation. Conclusions: These findings suggest that the induction of DUSP10/MKP5 expression by HMW-HA binding to CD44, leading to MMP13 suppression, involves multiple regulatory mechanisms, including PI3K/Akt and RhoA-activated ROK signaling, in addition to miRNA-mediated regulation. Elucidating these detailed molecular mechanisms may reveal novel biological activities that contribute to the therapeutic efficacy of HMW-HA against osteoarthritis.

Quality of life changes in patients suffering from knee osteoarthritis treated with bone marrow aspirate concentrate, platelet-rich plasma and hyaluronic acid injections

BACKGROUND

This study aimed to compare the effects of different treatments on quality of life in knee osteoarthritis patients. It focused on three therapies: bone marrow aspirate concentrate (BMAC), platelet-rich plasma (PRP), and hyaluronic acid (HA).

METHODOLOGY

The trial was conducted at a single center with 175 patients over a 12-month period with the knee OA, KL grade II-IV. Outcomes were measured using the WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) and SF-36 scales, which assess physical and emotional well-being. Linear mixed models (LMMs) were used to analyze which treatment had the most positive impact on quality of life.

RESULTS

Patients treated with BMAC showed the most substantial improvement, particularly in physical health and mobility (p ≤ 0,001). PRP outperformed HA in some aspects, but BMAC consistently led to greater gains. The most notable enhancements were seen in areas like role limitations due to physical health and overall physical functioning.

CONCLUSIONS

The study suggested that BMAC treatment may contribute to improved quality of life in patients with knee osteoarthritis, particularly in terms of physical function. The correlation between WOMAC and SF-36 scores supports these findings, indicating a potential role for BMAC in enhancing mobility.

CLINICAL TRIAL REGISTRATION

NCT03825133 (ClinicalTrials.gov).

The group A Streptococcus pathogenicity island RD2: virulence role and barriers to conjugative transfer

Serotype M28 isolates of the bacterial pathogen the group A Streptococcus (GAS; Streptococcus pyogenes), but not isolates of other serotypes, have a nonrandom association with cases of puerperal sepsis, a life-threatening infection that can occur in women following childbirth. In prior studies, we established that RD2, a pathogenicity island present in all M28 GAS isolates but mostly absent from other serotypes, is a factor in the M28-puerperal sepsis association. Here, we identified a significant reduction in the RD2 conjugation frequency in inter-serotype conjugation assays relative to intra-serotype assays. As isolates of most GAS serotypes produce an antiphagocytic hyaluronic acid capsule, while M28 isolates do not, we tested whether the capsule served as a barrier to RD2 acquisition or maintenance. The data showed that capsule production had no impact on the RD2 conjugation frequency or on the ability of RD2 to enhance vaginal colonization by GAS, but did inhibit the ability of RD2 to enhance GAS adherence to vaginal epithelial cell lines. Further molecular explanations for the inter-serotype barrier to RD2 conjugative transfer were investigated, and a conserved, chromosomally encoded Type I restriction-modification system was identified as being key. We also identified that RD2 modifies the GAS transcriptome, including mRNAs encoding virulence factors with adherence and dissemination roles, following exposure to human plasma. Our data provide insights into factors that contribute to the restriction of the RD2 pathogenicity island to discrete subsets of the GAS population.

Musculoskeletal Diseases: Aetiology, Clinical Implications, Rehabilitation and Treatment

Musculoskeletal diseases (MDs) are a wide range of conditions affecting bones, muscles, joints, and connective tissues and are among the leading causes of disability worldwide [...].

Peptides: Emerging Candidates for the Prevention and Treatment of Skin Senescence: A Review

One class of cosmetic compounds that have raised interest of many experts is peptides. The search for ingredients with good biocompatibility and bioactivity has led to the use of peptides in cosmetic products. Peptides are novel active ingredients that improve collagen synthesis, enhance skin cell proliferation, or decrease inflammation. Based on their mechanism of action, they can be classified into signal peptides, carrier peptides, neurotransmitter inhibitor peptides, and enzyme inhibitor peptides. This review focuses on the main types of peptides and their application in the cosmetic field, underlining their main limitations. One of the most significant drawbacks of cosmetic peptides is their poor permeability through membranes, which limits their delivery and effectiveness. As a result, this review follows the methods used for improving permeability through the stratum corneum. Increasing peptide bioavailability and stability for enhanced delivery to the desired site of action and visible effects have become central points for the latest research due to their promising features. For this purpose, several methods have been identified and described. Physical techniques include thermal ablation (radiofrequency and laser), electrical methods (electroporation, iontophoresis), mechanical approach (microneedles), and ultrasounds. As an alternative, innovative formulations have been developed in nano-systems such as liposomes, niosomes, ethosomes, nanoemulsions, and other nanomaterials to reduce skin irritation and improve product effectiveness. The purpose of this review is to provide the latest information regarding these noteworthy molecules and the reasoning behind their use in cosmetic formulations.

Hyaluronic Acid-Based Drug Delivery Systems for Cancer Therapy

In recent years, hyaluronic acid (HA) has attracted increasing attention as a promising biomaterial for the development of drug delivery systems. Due to its unique properties, such as high biocompatibility, low toxicity, and modifiability, HA is becoming a basis for the creation of targeted drug delivery systems, especially in the field of oncology. Receptors for HA overexpressed in subpopulations of cancer cells, and one of them, CD44, is recognized as a molecular marker for cancer stem cells. This review examines the role of HA and its receptors in health and tumors and analyzes existing HA-based delivery systems and their use in various types of cancer. The development of new HA-based drug delivery systems will bring new opportunities and challenges to anti-cancer therapy.

Hydrogel-Forming Microneedles and Applications in Interstitial Fluid Diagnostic Devices

Hydrogel-forming microneedles are constructed from or coated with polymeric, hydrophilic materials that swell upon insertion into the skin. Designed to dissolve or disintegrate postinsertion, these microneedles can deliver drugs, vaccines, or other therapeutics. Recent advancements have broadened their application scope to include the collection, transport, and extraction of dermal interstitial fluid (ISF) for medical diagnostics. This review presents a brief introduction to the characteristics of dermal ISF, methods for extraction and sampling, and critical assessment of the state-of-the-art in hydrogel-forming microneedles for ISF diagnostics. Key factors are evaluated including material composition, swelling behavior, biocompatibility, and mechanical strength necessary for effective microneedle performance and ISF collection. The review also discusses successful examples of dermal ISF assays and microneedle sensor integrations, highlighting notable achievements, identifying research opportunities, and addressing challenges with potential solutions. Despite the predominance of synthetic hydrogels in reported hydrogel-forming microneedle technologies due to their favorable swelling and gelation properties, there is a significant variety of biopolymers and composites reported in the literature. The field lacks consensus on the optimal material, composition, or fabrication methods, though emerging evidence suggests that processing and fabrication techniques are critical to the performance and utility of hydrogel-forming microneedles for ISF diagnostics.

A review of carbohydrate polymer-synthesized nanoparticles in cancer immunotherapy: Past, present and future perspectives

Cancer continues to be a leading factor in mortality and tackling it has been made difficult by the development of immune escape. Furthermore, alternative treatments like surgery, chemotherapy, and radiation have been unsuccessful in eradicating cancer. Despite being effective, they have not succeeded in providing a full cancer treatment and exhibit several negative effects. The field of immunotherapy has been improved by utilizing cancer vaccines, immune checkpoint inhibitors (ICIs), and adoptive cell transfer to enhance immune responses to tumors. Nevertheless, cancer cells need to adapt and become immune to immune reactions, leading to the need for innovative treatment methods. Carbohydrate polymers and their nanoparticles have been beneficial in improving cancer immunotherapy by being customizable to specifically target the immune system. These nanoparticles can change the tumor microenvironment and accelerate immunotherapy by affecting immune cells such as T cells and dendritic cells. Incorporating both chemotherapy and phototherapy into nanoparticles can improve immunotherapy. Furthermore, besides controlling immune reactions, carbohydrate polymer nanoparticles can also be used for theranostic purposes, where they are used to image tumor cells and activate the immune system to eradicate cancer.

Standardization and consensus in the development and application of bone organoids

Organoids, self-organized structures derived from stem cells cultured in a specific three-dimensional (3D) in vitro microenvironment, have emerged as innovative platforms that closely mimic in vivo cellular behavior, tissue architecture, and organ function. Bone organoids, a frontier in organoid research, can replicate the complex structures and functional characteristics of bone tissue. Recent advancements have led to the successful development of bone organoids, including models of callus, woven bone, cartilage, trabecular bone, and bone marrow. These organoids are widely utilized in establishing bone-related disease models, bone injury repair, and drug screening. However, significant discrepancies remain between current bone organoids and human skeletal tissues in terms of morphology and functionality, limiting their ability to accurately model human bone physiology and pathology. To address these challenges and promote standardization in the construction, evaluation, and application of bone organoids, we have convened experts and research teams with substantial expertise in the field. By integrating existing research findings, this consortium aims to establish a consensus to guide future research and application of bone organoids.

How to Fabricate Hyaluronic Acid for Ocular Drug Delivery

This review aims to examine existing research on the development of ocular drug delivery devices utilizing hyaluronic acid (HA). Renowned for its exceptional biocompatibility, viscoelastic properties, and ability to enhance drug bioavailability, HA is a naturally occurring biopolymer. The review discussed specific mechanisms by which HA enhances drug delivery, including prolonging drug residence time on ocular surfaces, facilitating controlled drug release, and improving drug penetration through ocular tissues. By focusing on these unique functionalities, this review highlights the potential of HA-based systems to revolutionize ocular treatment. Various fabrication techniques for HA-based ocular drug delivery systems, including hydrogels, nanoparticles, and microneedles, are discussed, highlighting their respective advantages and limitations. Additionally, this review explores the clinical applications of HA-based devices in treating a range of ocular diseases, such as dry eye syndrome, glaucoma, retinal disorders, and ocular infections. By comparing the efficacy and safety profiles of these devices with traditional ocular drug delivery methods, this review aims to provide a comprehensive understanding of the potential benefits and challenges associated with HA-based systems. Moreover, this review discusses current limitations and future directions in the field, such as the need for standardized fabrication protocols, long-term biocompatibility studies, and large-scale clinical trials. The insights and advancements presented in this review aim to guide future research and development efforts, ultimately enhancing the effectiveness of ocular drug delivery and improving patient outcomes.

Hyaluronic acid-coated zein nanoparticle-mediated resveratrol therapy for the reduction of cisplatin-associated nephrotoxicity

Cisplatin (CDDP) is commonly used as an anticancer drug in clinical practice, but severe nephrotoxicity restricts it from exerting anticancer effects. Natural drugs, such as resveratrol, can alleviate the side effects of cisplatin, but their low solubility and gastrointestinal effects prevent them from working. Herein, we developed nanoparticles for kidney injury consisting of a biocompatible material, zein, as a carrier. HA-Zein/Res NPs were fabricated using low-molecular-weight hyaluronic acid coatings. This preparation is non-cytotoxic to renal tubular epithelial cells and can be used with confidence. Low-molecular-weight hyaluronic acid has inflammation-targeting properties and CDDP damage causes renal inflammation. Owing to this property of the low-molecular-weight hyaluronic acid coating, in vivo imaging experiments in mice demonstrated that the HA-Zein/Res NPs enabled more nanoparticles to accumulate in the renal sites affected by inflammation. Efficient resveratrol delivery alleviated kidney injury, and experiments demonstrated that HA-Zein/Res NPs could treat kidney injury while reducing the serum creatinine and urea nitrogen levels in mice. Collectively, these results indicated that this nanomaterial is a promising agent for reducing the clinical nephrotoxicity of cisplatin.

Efficacy and safety of non-cross-linked hyaluronic acid compound in the treatment of keratosis pilaris: A split-body randomized clinical trial

BACKGROUND

Keratosis pilaris (KP) is a prevalent benign dermatological condition characterized by small bumps at the hair follicles alongside surrounding redness, significantly impacting both aesthetics and mental well-being.

OBJECTIVE

This study investigated the potential benefits of a non-cross-linked hyaluronic acid (HA) compound for treating KP.

METHODS

A split-body, investigator-blinded, randomized, intraindividual comparative clinical trial was conducted. The non-cross-linked HA compound was injected into KP-affected regions on both upper arms. The treatment was delivered across four sessions scheduled at 4-week intervals. Blinded physicians and patients assessed differences in erythema, skin roughness, and overall scores between treated and control areas at the final follow-up visit. At the 12th and 24th weeks post-treatment, a four-point scale was utilized to assess subjects' perceived treatment efficacy. Additionally, dermoscopic images, histological alterations, and adverse events were monitored.

RESULTS

Physician assessments revealed a significant reduction in roughness and overall scores for treated areas compared to controls. Patient self-assessments also reflected improvements in roughness, redness, and overall scores for treated sides at the final visit, with 35.71% of patients demonstrating sustained improvement in redness and 71.43% reporting persistent improvements in roughness at 24th weeks post-treatment. The dermatoscopic examinations revealed a notable enhancement in both the quantity of follicular plugs and the extent of erythema among the subjects in the treatment group. Histopathological outcomes also demonstrated improvement.

CONCLUSION

This study suggests that the non-cross-linked HA compound effectively improves skin roughness and promotes hair shaft growth in KP treatment, demonstrating a favorable safety profile. These findings position it as a potentially viable alternative therapy in clinical practice.

Comparative fluorophotometric evaluation of the ocular surface retention time of cross-linked and linear hyaluronic acid ocular eye drops on healthy dogs

PURPOSE

Evaluate and compare the retention time on the canine ocular surface of crosslinked hyaluronic acid (X-HA), linear hyaluronic acid (L-HA) and saline solution using fluorescent compounds (fluorescein sodium salt, Alexa Fluor 488 cadaverine and Alexa Fluor 488 maleimide).

METHODS

0.9% saline solution (SAL) was combined with fluorescein sodium salt. X-HA and L-HA were covalently modified using Alexa Fluor 488 reactive moieties. Eye drops were applied to 70 eyes of 35 dogs that were previously assessed and determined to have a normal ocular surface. Employing a blue light filter (450-490 nm), digital images were captured from instillation to 180 min. Images were analyzed to assess the percent of the total ocular area covered with green fluorescence at various time points.

RESULTS

X-HA exhibited a dual phase behavior: A broad microgel coverage first, followed by accumulation in tear film meniscus and medial canthus in the second phase, remaining in contact with the ocular surface up to 180 min. Coverage with L-HA and SAL eye drops quickly migrated to the tear meniscus. No traces of the fluorescent compounds were observed by 45 min in eyes treated with SAL solution compound and, by 120 min, eyes treated with L-HA.

CONCLUSIONS

X-HA exhibited a significantly increased ocular surface contact time with the ocular surface compared with L-HA and SAL. Not only could this indicate extended lubrication time but also supports the potential use of this compound as a method for topical sustained-release drug application.

Hyaluronic acid application strategies for plant bioactive component delivery: A review

Despite the notable therapeutic effects of bioactive components derived from naturally occurring medicinal plants, various factors such as low solubility, poor bioavailability, possible toxicity, and inadequate tumor targeting capabilities generally hinder their full potential. Hyaluronic Acid (HA), a naturally occurring polysaccharide, has recently attracted significant research interest from scientists owing to its ability to precisely target tumors, anionic polysaccharide properties, and easily modifiable unique structure. In addition to offering a solid backing for delivering plant bioactive constituents, these remarkable attributes also have considerable implications for drug delivery systems in the future. This review delves into HA's application in delivering plant bioactive components, starting with a summary of HA's functional characteristics and detailing its strategies for single and dual-component delivery. The review also provides a forward-looking analysis of the challenges encountered in developing HA-based drug delivery systems.

Methods for determining the structure and physicochemical properties of hyaluronic acid and its derivatives: A review

Hyaluronic acid (HA) is a linear high molecular weight polymer ubiquitously distributed in humans and animals. The D-glucuronic acid and N-acetyl-D-glucosamine repeating disaccharide backbone along with variable secondary and tertiary structures endows HA with unique rheological characteristics as well as diverse biological functions such as maintaining tissue homeostasis and mediating cell functions. Due to its excellent biocompatibility, biodegradability, viscoelasticity and moisturizing properties, natural HA and its chemically modified derivatives are widely used in medical, pharmaceutical, food and cosmetic industries. For broad application purposes, abundant HA-based biochemical products have been developed, including the methodologies for characterization of these products. This review provides an overview focusing on the methods used for determining HA structure as well as the strategies for constructing its derivatives. Apart from the analytical approaches for defining the physicochemical properties of HA (e.g., molecular weight, rheology and swelling capacity), quantitative methods for assessing the purity of HA-based materials are discussed. In addition, the biological functions and potential applications of HA and its derivatives are briefly embarked and perspectives in methodological development are discussed.

Targeting mitochondria in Cancer therapy: Machine learning analysis of hyaluronic acid-based drug delivery systems

BACKGROUND

Mitochondrial alterations play a crucial role in the development and progression of cancer. Dysfunctional mitochondria contribute to the acquisition of key hallmarks of cancer, including sustained proliferative signaling, evasion of growth suppressors, and resistance to cell death. Consequently, targeting mitochondrial dysfunction has emerged as a promising therapeutic strategy. Hyaluronic acid (HA), a naturally occurring glycosaminoglycan, has garnered significant attention due to its multifaceted roles in cancer biology.

METHODS

We employed a Systematic Literature Review (SLR) approach to examine a collection of 90 scientific publications using a text mining technique leveraging the Latent Dirichlet Allocation (LDA) algorithm.

RESULTS

The result of this activity, performed through the MySLR digital platform, allowed us to identify a set of two distinct topics representing the research domain. Specifically, Topic 1 comprised 41 papers, while Topic 2 comprised 49 papers.

CONCLUSIONS

The computational analysis highlighted that the integration of HA into drug delivery systems represents a promising approach to enhance the effectiveness and safety of cancer therapies. The discussed clinical trials provided compelling evidence of the potential of HA-based treatments in targeting cancer cells while minimizing adverse effects on healthy tissues.

ACL injury management: a comprehensive review of novel biotherapeutics

The anterior cruciate ligament (ACL) is integral to the stability of the knee joint, serving to limit anterior tibial translation and regulate rotational movements. ACL injuries are among the most common and debilitating forms of knee trauma, often resulting in joint effusion, muscular atrophy, and diminished athletic capabilities. Despite the established efficacy of ACL reconstruction as the standard treatment, it is not uniformly successful. Consequently, there is a growing interest in novel biotherapeutic interventions as potential alternatives. This comprehensive review examines the latest advancements in ACL biotherapy, encompassing the application of hyaluronic acid, self-assembled short peptides, growth factors, stem cell therapy, gene therapy, platelet-rich plasma therapy, bone marrow aspirate concentrate cells, extracorporeal shock wave, electrical stimulation and cross bracing protocol. The collective aim of these innovative treatments is to facilitate the restoration of the ACL's native biological and biomechanical integrity, with the ultimate goal of enhancing clinical outcomes and the functional recovery of affected individuals.

Biomimetic Proteoglycans for Intervertebral Disc (IVD) Regeneration

Intervertebral disc degeneration, which leads to low back pain, is the most prevalent musculoskeletal condition worldwide, significantly impairing quality of life and imposing substantial socioeconomic burdens on affected individuals. A major impediment to the development of any prospective cell-driven recovery of functional properties in degenerate IVDs is the diminishing IVD cell numbers and viability with ageing which cannot sustain such a recovery process. However, if IVD proteoglycan levels, a major functional component, can be replenished through an orthobiological process which does not rely on cellular or nutritional input, then this may be an effective strategy for the re-attainment of IVD mechanical properties. Furthermore, biomimetic proteoglycans (PGs) represent an established polymer that strengthens osteoarthritis cartilage and improves its biomechanical properties, actively promoting biological repair processes. Biomimetic PGs have superior water imbibing properties compared to native aggrecan and are more resistant to proteolytic degradation, increasing their biological half-life in cartilaginous tissues. Methods have also now been developed to chemically edit the structure of biomimetic proteoglycans, allowing for the incorporation of bioactive peptide modules and equipping biomimetic proteoglycans as delivery vehicles for drugs and growth factors, further improving their biotherapeutic credentials. This article aims to provide a comprehensive overview of prospective orthobiological strategies that leverage engineered proteoglycans, paving the way for novel therapeutic interventions in IVD degeneration and ultimately enhancing patient outcomes.

Advances of naturally derived biomedical polymers in tissue engineering

The extensive utilization of natural polymers in tissue engineering is attributed to their excellent biocompatibility, degradability, and resemblance to the natural extracellular matrix. These polymers have a wide range of applications such as delivering therapeutic medicine, detecting diseases, sensing biological substances, promoting tissue regeneration, and treating diseases. This is a brief review of current developments in the properties and uses of widely used biomedical polymers derived from nature. Additionally, it explores the correlation between the characteristics and functions of these materials in different biomedical applications and highlights the prospective direction for the advancement of natural polymer materials in tissue engineering.

Impact of Hyaluronic Acid and Other Re-Epithelializing Agents in Periodontal Regeneration: A Molecular Perspective

This narrative review delves into the molecular mechanisms of hyaluronic acid (HA) and re-epithelializing agents in the context of periodontal regeneration. Periodontitis, characterized by chronic inflammation and the destruction of tooth-supporting tissues, presents a significant challenge in restorative dentistry. Traditional non-surgical therapies (NSPTs) sometimes fail to fully manage subgingival biofilms and could benefit from adjunctive treatments. HA, with its antibacterial, antifungal, anti-inflammatory, angiogenic, and osteoinductive properties, offers promising therapeutic potential. This review synthesizes the current literature on the bioactive effects of HA and re-epithelializing agents, such as growth factors and biomaterials, in promoting cell migration, proliferation, and extracellular matrix (ECM) synthesis. By modulating signaling pathways like the Wnt/β-catenin, TGF-β, and CD44 interaction pathways, HA enhances wound healing processes and tissue regeneration. Additionally, the role of HA in facilitating cellular crosstalk between epithelial and connective tissues is highlighted, as it impacts the inflammatory response and ECM remodeling. This review also explores the combined use of HA with growth factors and cytokines in wound healing, revealing how these agents interact synergistically to optimize periodontal regeneration. Future perspectives emphasize the need for further clinical trials to evaluate the long-term outcomes of these therapies and their potential integration into periodontal treatment paradigms.

Tunnel Technique and Subepithelial Connective Tissue Graft, With or Without Cross-Linked Hyaluronic Acid, in the Treatment of Multiple Gingival Recessions: Prognostic Parameters for Clinical Treatment Outcomes of Randomized Controlled Trial

Objectives: This study aimed to investigate factors that influence the 12-month outcomes after the treatment of multiple gingival recessions (GRs) with a modified coronally advanced tunnel (MCAT) and a subepithelial connective tissue graft (SCTG), with cross-linked hyaluronic acid (HA, tests) or without (controls). Materials and Methods: Twenty-four patients with 266 GRs were treated. A logistic regression model was set to identify the baseline parameters that could predict the 12-month outcomes. The study protocol was registered at ClinicalTrials.gov (ID No. NCT05045586). Results: The evaluated clinical and esthetic parameters showed marked improvement in both groups without any statistically significant differences between the groups, with the exception of the soft tissue texture (STT). The STT was in favor of the HA group (0.96 versus 0.73, p = 0.0091). The likelihood of an MRC > 85%, of achieving CRC, and of gaining an RES = 10 was the highest for the incisors (reference group) and the lowest for the molars (OR = 0.046, p = 0.005). With each 1 mm increase in the baseline clinical attachment level, the odds of failure (MRC < 85%, not achieving CRC) increased, whereas each 1 mm increase in the baseline keratinized tissue width (KTW) improved the chances of an MRC > 85%, of achieving CRC, and of gaining an RES = 10. The application of HA increased the likelihood of a perfect RES more than twofold (OR = 2.683, p = 0.001). Conclusions: The application of HA improved the 12-month esthetic outcomes after the treatment of GRs with the MCAT technique. The baseline CAL, KTW, and tooth type predicted the 12-month MRC, CRC, and RES. An evaluation of the baseline characteristics of the surgical area might help clinicians develop individualized treatment plans.

Nerol mitigates dexamethasone-induced skin aging by activating the Nrf2 signaling pathway in human dermal fibroblasts

Collagen and hyaluronic acid are essential components of the dermis that collaborate to maintain skin elasticity and hydration due to their unique biochemical properties and interactions within the extracellular matrix. Prolonged exposure to glucocorticoids can induce skin aging, which manifests as diminished collagen content and hyaluronic acid levels in the dermis. Nerol, a monoterpene alcohol found in essential oils, was examined in this study for its potential to counteract glucocorticoid-induced skin aging and the underlying mechanism behind its effects. Our findings reveal that non-toxic concentrations of nerol treatment can reinstate collagen content and hyaluronic acid levels in human dermal fibroblasts treated with dexamethasone. Mechanistically, nerol mitigates dexamethasone-induced oxidative stress by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. The protective effects of nerol were significantly abrogated when the Nrf2 pathway was inhibited using the specific inhibitor ML385. In conclusion, nerol protects human dermal fibroblasts against glucocorticoid-induced skin aging by ameliorating oxidative stress via activation of the Nrf2 pathway, thereby highlighting its potential as a therapeutic agent for preventing and treating glucocorticoid-induced skin aging.

Cloning and characterization of a hyaluronate lyase EsHyl8 from Escherichia sp. A99

Hyaluronidase, an enzyme that degrades hyaluronic acid (HA), is utilized in clinical settings to facilitate drug diffusion, manage extravasation, and address injection-related complications linked to HA-based fillers. In this study, a novel hyaluronate lyase EsHyl8 was cloned, expressed, and characterized from Escherichia sp. A99 of human intestinal origin. This lyase belongs to polysaccharide lyase (PL) family 8, and showed specific activity towards HA. EsHyl8 exhibited optimal degradation at 40 °C and pH 6.0. EsHyl8 exhibited a high activity of 376.32 U/mg among hyaluronidases of human gut microorganisms. EsHyl8 was stable at 37 °C and remained about 70 % of activity after incubation at 37 °C for 24 h, demonstrating excellent thermostability. The activity of EsHyl8 was inhibited by Zn2+, Cu2+, Fe3+, and SDS. EsHyl8 was an endo-type enzyme whose end-product was unsaturated disaccharide. This study enhances our understanding of hyaluronidases from human gut microorganisms.

Hyaluronan size and concentration: Effect on key biophysical and biochemical features

The effect of hyaluronan (HA) molecular weight (MW) and concentration (c) on key features of HA-formulations was systematically studied, in vitro, exploring the widest range/number of MW/c to date. Nine pharmaceutical grade HA samples (60-2500 kDa) were hydrodynamically characterized using Size Exclusion Chromatography-Triple Detector Array (SEC-TDA) also providing conformational data. HAs aqueous solutions (thirteen concentrations in the range 0.1-32 g/L) were tested for dynamic viscosity (η). η dependence on MW/c was analyzed providing mathematical correlations not only for the specific zero-shear viscosity, but also for the critical shear rate and the shear-thinning-extent. Besides confirming the dilute and semi-dilute c-regimes for the HAs, a third concentrated regime was evidenced for the 220-2500 kDa samples. Data on how MW affects the dependence of viscosity parameters on c and vice-versa were provided. The 60-90 kDa HAs proved stable to thermal sterilization and enzymatically catalyzed hydrolysis, while the 220-2500 kDa samples depolymerized to an extent depending, beyond concentration, on MW. HA size did not significantly affect fibroblasts behavior: under the conditions here tested, the HAs similarly sustained human dermal fibroblasts growth and wound healing also showing comparable effect on collagen-I, elastin and hyaluronan synthase-1 expression. Overall, results valuably contribute to the understanding of the HA MW/c impact on the rheological, stability and biochemical features of the final formulations, also providing mathematical correlations allowing for their optimization towards specific performance.

Enhancing glioma treatment with 3D scaffolds laden with upconversion nanoparticles and temozolomide in orthotopic mouse model

Targeted drug delivery for primary brain tumors, particularly gliomas, is currently a promising approach to reduce patient relapse rates. The use of substitutable scaffolds, which enable the sustained release of clinically relevant doses of anticancer medications, offers the potential to decrease the toxic burden on the patient's organism while also enhancing their quality of life and overall survival. Upconversion nanoparticles (UCNPs) are being actively explored as promising agents for detection and monitoring of tumor growth, and as therapeutic agents that can provide isolated therapeutic effects and enhance standard chemotherapy. Our study is focused on the feasibility of constructing scaffolds using methacrylated hyaluronic acid with additional impregnation of UCNPs and the chemotherapeutic drug temozolomide (TMZ) for glioma treatment. The designed scaffolds have been demonstrated their efficacy as a drug and UCNPs delivery system for gliomas. Using the aggressive orthotopic glioma model in vivo, it was found that the scaffolds possess the capacity to ameliorate neurological disorders in mice. Moreover, upon intracranial co-implantation of the scaffolds and glioma cells, the constructs disintegrate into distinct segments, augmenting the release of UCNPs into the surrounding tissue and concurrently reducing postoperative damage to brain tissue. The use of TMZ in the scaffold composition contributed to restraining glioma development and the reduction of tumor invasiveness. Our findings unveil promising prospects for the application of photopolymerizable biocompatible scaffolds in the realm of neuro-oncology.

Natural biopolymer-based hydrogels: an advanced material for diabetic wound healing

A diabetic foot ulcer (DFU) is an open sore or wound that typically develops on the bottom of the foot. Almost 15% of people with diabetes are suffering from delayed wound healing worldwide. The main vehicle for the development of ulcers in the diabetic population is poor circulation and peripheral neuropathy. Chronic injuries from diabetes frequently lead to traumatic lower leg amputations. Hydrogels are three-dimensional gels that can be fabricated from natural polymers and synthetic polymers. Biopolymers are flexible, elastic, or fibrous materials that come from a natural source, such as plants, animals, bacteria, or other living things. Some of the naturally occurring polymers that are frequently employed in wound dressing applications include polysaccharides and proteins. These polymers can be employed for many therapeutic applications because of their inherent biocompatibility, low immunogenicity, non-toxicity, and biodegradability. They represent a tuneable platform for enhancing skin healing. Therefore, this review paper interprets how natural biopolymers and their various hydrogel forms can be potentially used for diabetic wound healing.

Delivery of natural products via polysaccharide-based nanocarriers for cancer therapy: A review on recent advances and future challenges

Cancer, caused by uncontrolled proliferation of abnormal cells, has long been a global public health issue. For decades, natural products have been proven to be an essential source for novel anticancer drug discovery. But their instability, low solubility and bioavailability, poor targeting impede therapeutic efficacy. With the development of nanotechnology, nanomedicine delivery systems have emerged as promising strategies to improve bioavailability and enhance the therapeutic efficacy of drugs. However, constructing suitable nanocarrier is still a major challenge. Polysaccharides are extensively employed as carrier materials in nanomedicine delivery systems, owing to their unique physicochemical properties, biocompatibility and low immunogenicity. Polysaccharide-based nanomedicine delivery systems show high drug delivery efficiency, controlled drug release, and precise tumor targeting. This paper reviews influencing factors in the construction of polysaccharide-based nanocarriers and the application of polysaccharide-based nanocarriers for the delivery of natural products in treating various cancers. It focuses on their in vitro and in vivo anticancer efficacy and mechanisms. Furthermore, the review contrasts the capabilities and limitations of polysaccharide-based nanocarriers with traditional delivery methods, underlining their potential to enable targeted, reduced toxicity and excellent cancer treatment modalities. Finally, we discuss the current research limitations and future prospects in this emerging field.

How to fight acute sun damage? Current skin care strategies

Excessive exposure to sunlight can contribute for skin photo-damage, such as sunburn, dryness, wrinkles, hyperpigmentation, immunosuppressive events and skin sensitization reactions. The use of aftersun products is an effective strategy to reduce the visible signs and symptoms of acute photodamage in the skin. Aiming to unveil the active ingredients able to offset acute sun damage, this work focuses on the characterization of the aftersun products market. A total of 84 after-sun formulations from 41 international brands currently marketed in Portugal were analyzed concerning the composition described on the product label, identifying natural and synthetic/semi-synthetic ingredients with the ability to mitigate solar-induced effects. The majority of aftersun formulations contained ingredients derived from terrestrial and marine sources (> 80%). An in-depth examination of these compounds is also offered, revealing the top of the most used natural and synthetic/semi-synthetic ingredients present in aftersun products, as well as their mechanism of action. A critical appraisal of the scientific data was made aiming to highlight the scientific evidence of ingredients able to mitigate skin photodamage. Amino acids and peptides, and A. barbadensis extract were tested for their in vivo efficacy. Nevertheless, all the ingredients were analyzed with in vitro studies as preliminary screening before in vivo, ex vivo and/or clinical studies. In summary, this study provides an overview of the use of active ingredients in commercial aftersun products to understand better the benefits associated with their use in cosmetic formulations and identify opportunities for innovation.

Hydrogels with Antioxidant Microparticles Systems Based on Hyaluronic Acid for Regenerative Wound Healing

This research focuses on the synthesis of hydrogels exhibiting enhanced antioxidant properties derived from hyaluronic acid (HA) and poly(ethylene brassylate-co-squaric acid) (PEBSA), a copolymacrolactone that have the ability to be used in drug delivery applications. Quercetin (Q), a bioflavonoid with strong antioxidant properties, is employed as a bioactive compound. The biomolecule is encapsulated in the polymeric network using different entrapment techniques, including the initial formation of a complex between PEBSA and Q, which is demonstrated through the dynamic light scattering technique. Fourier transform infrared spectroscopy (FT-IR) and rheological studies confirm the formation of the hydrogels, revealing the occurrence of physical interactions between the synthetic polymer and the polysaccharide. Moreover, the hydrogels demonstrate biocompatible properties after direct contact with the HDFa cell line and antioxidant properties, as revealed by DPPH tests.

Targeting inflammation with hyaluronic acid-based micro- and nanotechnology: A disease-oriented review

Inflammation is a pivotal immune response in numerous diseases and presents therapeutic challenges. Traditional anti-inflammatory drugs and emerging cytokine inhibitors encounter obstacles such as limited bioavailability, poor tissue distribution, and adverse effects. Hyaluronic acid (HA), a versatile biopolymer, is widely employed to deliver therapeutic agents, including anti-inflammatory drugs, genes, and cell therapies owing to its unique properties, such as hydrophilicity, biodegradability, and safety. HA interacts with cell receptors to initiate processes such as angiogenesis, cell proliferation, and immune regulation. HA-based drug delivery systems offer dual strategies for effective inflammation management, capitalizing on passive and active mechanisms. This synergy permits the mitigation of inflammation by lowering the doses of anti-inflammatory drugs and their off-target adverse effects. A diverse array of micro- and nanotechnology techniques enable the fabrication of tailored HA-engineered systems, including hydrogels, microgels, nanogels, microneedles, nanofibers, and 3D-printed scaffolds, for diverse formulations and administration routes. This review explores recent insights into HA pharmacology in inflammatory conditions, material design, and fabrication methods, as well as its applications across a spectrum of inflammatory diseases, such as atherosclerosis, psoriasis, dermatitis, wound healing, rheumatoid arthritis, osteoarthritis, inflammatory bowel disease, and colitis, highlighting its potential for clinical translation.

Accurate prediction of hyaluronic acid concentration under temperature perturbations using near-infrared spectroscopy and deep learning

Accurate prediction of the concentration of a large number of hyaluronic acid (HA) samples under temperature perturbations can facilitate the rapid determination of HA's appropriate applications. Near-infrared (NIR) spectroscopy analysis combined with deep learning presents an effective solution to this challenge, with current research in this area being scarce. Initially, we introduced a novel feature fusion method based on an intersection strategy and used two-dimensional correlation spectroscopy (2DCOS) and Aquaphotomics to interpret the interaction information in HA solutions reflected by the fused features. Subsequently, we created an innovative, multi-strategy improved Walrus Optimization Algorithm (MIWaOA) for parameter optimization of the deep extreme learning machine (DELM). The final constructed MIWaOA-DELM model demonstrated superior performance compared to partial least squares (PLS), extreme learning machine (ELM), DELM, and WaOA-DELM models. The results of this study can provide a reference for the quantitative analysis of biomacromolecules in complex systems.

Structural Rheology in the Development and Study of Complex Polymer Materials

The progress in polymer science and nanotechnology yields new colloidal and macromolecular objects and their combinations, which can be defined as complex polymer materials. The complexity may include a complicated composition and architecture of macromolecular chains, specific intermolecular interactions, an unusual phase behavior, and a structure of a multi-component polymer-containing material. Determination of a relation between the structure of a complex material, the structure and properties of its constituent elements, and the rheological properties of the material as a whole is the subject of structural rheology-a valuable tool for the development and study of novel materials. This work summarizes the author's structural-rheological studies of complex polymer materials for determining the conditions and rheo-manifestations of their micro- and nanostructuring. The complicated chemical composition of macromolecular chains and its role in polymer structuring via block segregation and cooperative hydrogen bonds in melt and solutions is considered using tri- and multiblock styrene/isoprene and vinyl acetate/vinyl alcohol copolymers. Specific molecular interactions are analyzed in solutions of cellulose; its acetate butyrate; a gelatin/carrageenan combination; and different acrylonitrile, oxadiazole, and benzimidazole copolymers. A homogeneous structuring may result from a conformational transition, a mesophase formation, or a macromolecular association caused by a complex chain composition or specific inter- and supramolecular interactions, which, however, may be masked by macromolecular entanglements when determining a rheological behavior. A heterogeneous structure formation implies a microscopic phase separation upon non-solvent addition, temperature change, or intense shear up to a macroscopic decomposition. Specific polymer/particle interactions have been examined using polyethylene oxide solutions, polyisobutylene melts, and cellulose gels containing solid particles of different nature, demonstrating the competition of macromolecular entanglements, interparticle interactions, and adsorption polymer/particle bonds in governing the rheological properties. Complex chain architecture has been considered using long-chain branched polybutylene-adipate-terephthalate and polyethylene melts, cross-linked sodium hyaluronate hydrogels, asphaltene solutions, and linear/highly-branched polydimethylsiloxane blends, showing that branching raises the viscosity and elasticity and can result in limited miscibility with linear isomonomer chains. Finally, some examples of composite adhesives, membranes, and greases as structured polymeric functional materials have been presented with the demonstration of the relation between their rheological and performance properties.

Is there a duration-characteristic relationship for trypsin exposure on tendon? A study on anterior cruciate ligament reconstruction in a rabbit model

Background

Decellularized allograft tendons are highly regarded for their accessibility and the reduced risk of immune rejection, making them a promising choice for grafting due to their favorable characteristics. However, effectively integrating reconstructed tendons with host bone remains a significant clinical challenge.

Purpose

This study aims to investigate the relationship between the duration of tendon exposure to trypsin and its impact on tendon biomechanical properties and healing capacity.

Methods

Morphological assessments and biochemical quantifications were conducted. Allograft tendons underwent heterotopic transplantation into the anterior cruciate ligament (ACL) in a rabbit model, with specimens harvested 6 weeks post-surgery for a comparative analysis of cell adhesion strength and mechanical performance. Duration-response curves were constructed using maximum stress and cell adhesion quantity as primary indicators.

Results

The trypsin treatment enhanced cell adhesion on the tendon surface. Adhesion rates in the control group vs. the experimental groups were as follows: 3.10 ± 0.56% vs. 4.59 ± 1.51%, 5.36 ± 1.24%, 6.12 ± 1.98%, and 8.27 ± 2.34% (F = 6.755, p = 0.001). However, increasing treatment duration led to a decline in mechanical properties, with the ultimate load (N) in the control vs. experimental groups reported as 103.30 ± 10.51 vs. 99.59 ± 4.37, 93.15 ± 12.38, 90.42 ± 7.87, and 82.68 ± 6.89, F = 4.125 (p = 0.013).

Conclusion

The findings reveal an increasing trend in adhesion effectiveness with prolonged exposure duration, while mechanical strength declines. The selection of the optimal processing duration should involve careful consideration of the benefits derived from both outcomes.

ViSCNOVAS: A Novel Classification System for Hyaluronic Acid-Based Gels in Orthobiologic Products and Regenerative Medicine

Hyaluronic acid (HA), a naturally occurring polysaccharide, holds immense potential in regenerative medicine due to its diverse biological functions and clinical applications, particularly in gel formulations. This paper presents a comprehensive exploration of HA, encompassing its origins, molecular characteristics, and therapeutic roles in gel-based interventions. Initially identified in bovine vitreous humor, HA has since been found in various tissues and fluids across vertebrate organisms and bacterial sources, exhibiting consistent physicochemical properties. The synthesis of HA by diverse cell types underscores its integral role in the extracellular matrix and its relevance to tissue homeostasis and repair. Clinical applications of HA, particularly in addressing musculoskeletal ailments such as osteoarthritis, are examined, highlighting its efficacy and safety in promoting tissue regeneration and pain relief. Building upon this foundation, a novel classification system for HA-based interventions is proposed, aiming to standardize treatment protocols and optimize patient outcomes. The ViSCNOVAS classification system refers to viscosity, storage, chain, number, origin, volume, amount, and size. This classification is specifically designed for HA-based orthobiologic products used in regenerative medicine, including orthopedics, sports medicine, aesthetics, cosmetic dermatology, and wound healing. It aims to provide clinicians with a structured framework for personalized treatment strategies. Future directions in HA research are also discussed, emphasizing the need for further validation and refinement of the proposed classification system to advance the field of regenerative medicine. Overall, this manuscript elucidates the biological functions of hyaluronic acid and its potential in clinical practice while advocating for standardization to enhance patient care in various regenerative applications.