Hyaluronic acid promotes angiogenesis by inducing RHAMM-TGFβ receptor interaction via CD44-PKCδ

Development of a bioactive hyaluronic acid hydrogel functionalised with antimicrobial peptides for the treatment of chronic wounds

Chronic wounds present significant clinical challenges due to delayed healing and high infection risk. This study presents the development and characterisation of acrylated hyaluronic acid (AcHyA) hydrogels functionalised with gelatin (G) and the antimicrobial peptide (AMP) PP4-3.1 to enhance cellular responses while providing antimicrobial activity. AcHyA-G and AcHyA-AMP hydrogels were formed via thiol-acrylate crosslinking, enabling in situ AcHyA hydrogel formation with stable mechanical properties across varying gelatin concentrations. Biophysical characterisation of AcHyA-G hydrogels showed rapid gelation, elastic behaviour, uniform mesh size, and consistent molecular diffusion across all formulations. Moreover, the presence of gelatin enhanced stability without affecting the hydrogel's degradation kinetics. AcHyA-G hydrogels supported the adhesion and spreading of key cell types involved in wound repair (dermal fibroblasts and endothelial cells), with 0.5% gelatin identified as the optimal effective concentration. Furthermore, the conjugation of the AMP conferred bactericidal activity against Staphylococcus aureus and Escherichia coli, two of the most prevalent bacterial species found in chronically infected wounds. These results highlight the dual function of AcHyA-AMP hydrogels in promoting cellular responses and antimicrobial activity, offering a promising strategy for chronic wound treatment. Further in vivo studies are needed to evaluate their efficacy, including in diabetic foot ulcers.

Comparative Study on Interdental Papillae Regeneration: Leukocyte Platelet-Rich Fibrin By-product versus Hyaluronic Acid Injections in Modified Open Gingival Embrasure Model

OBJECTIVES

 This study aims to compare the regenerative effects of various by-products of human leukocyte platelet-rich fibrin (L-PRF), including L-PRF exudate, concentrated PRF (C-PRF), and a mixture of the two, with hyaluronic acid (HA) specifically for interdental papillae reconstruction.

MATERIALS AND METHODS

 The L-PRF was obtained by centrifuging 10 mL of human blood in a fixed-angle centrifuge at 2,700 rpm for 12 minutes. After centrifugation, the L-PRF layer was separated, and platelet and leukocyte counts were performed. An in vivo study was conducted using Sprague-Dawley rats subjected to a modified open gingival embrasure (OGE) model for 7 days. Once the OGE was established, 20 µL of L-PRF exudate (n = 3), C-PRF (n = 3), a combination of L-PRF exudate and C-PRF (n = 3), HA (n = 3), and phosphate-buffered saline (n = 3) were injected 2 mm from the tip of the papillae using a 30G syringe. Clinical parameters, including OGE width and spring papilla distance (SPD), were observed on days 7 and 14. On day 14, histological observations included fibroblast count, blood vessel presence, epithelial width, and collagen density, while proliferating cell nuclear antigen expression was assessed immunohistochemically.

STATISTICAL ANALYSIS

 The SPD on day 7, along with all histological and immunohistochemical data, were normally distributed and analyzed by one-way analysis of variance followed by Tukey's honestly significant difference test. In contrast, the Kruskal-Wallis' test was used to analyze the OGE width and SPD on day 14, which was not normally distributed.

RESULTS

 The cell counts indicated that most platelets and leukocytes were in the C-PRF layer. The L-PRF membrane by-product increased fibroblast proliferation more effectively than HA (p < 0.05). Only C-PRF significantly enhanced the vascularization and epithelialization of the papillae (p < 0.05). However, the observed cellular and molecular changes increased at day 7 postinjection and did not impact collagen density or interdental papilla height.

CONCLUSION

 The regenerative effect of C-PRF injection is superior to that of HA and other L-PRF by-products, as it promotes papillae regeneration by enhancing fibroblast activity, vascularization, and epithelialization. These findings show the potential impact of L-PRF by-products as a nonsurgical papillae reconstruction treatment.

Matrix Stiffness Regulates Mechanotransduction and Vascular Network Formation of hiPSC-Derived Endothelial Progenitors Encapsulated in 3D Hydrogels

The mechanical properties of the extracellular matrix (ECM), particularly stiffness, regulate endothelial progenitor responses during vascular development, yet their behavior in physiologically compliant matrices (<1 kPa) remains underexplored. Using norbornene-modified hyaluronic acid (NorHA) hydrogels with tunable stiffness (190-884 Pa), we investigated how hydrogel stiffness influences cell morphology, endothelial maturation, mechanotransduction, and microvascular network formation in human induced pluripotent stem cell-derived endothelial progenitors (hiPSC-EPs). Our findings reveal a stiffness-dependent tradeoff between mechanotransduction and vascular network formation. At intermediate stiffness (551 Pa), cells exhibited the greatest increase in endothelial marker CD31 expression and Yes-associated protein (YAP)/ transcriptional coactivator with PDZ-binding motif (TAZ) nuclear translocation, indicating enhanced mechanotransduction and endothelial maturation. However, this did not translate to superior plexus formation. Instead, the most compliant matrix (190 Pa) supported greater vascular connectivity, characterized by longer branches (∼0.03/volume vs. 0.015 at 551 Pa) and enhanced actin remodeling. 3D cell contraction measurements revealed a 15.6-fold higher basal displacement in compliant hydrogels, suggesting that cell-generated forces and matrix deformability collectively drive vascular morphogenesis. Unlike prior studies focusing on pathological stiffness ranges (>10 kPa), our results emphasize that vascularization is not solely driven by the most mechanotransductive environment but rather by a balance of compliance, contractility, and cell-induced remodeling. These findings underscore the need to design hydrogels that provide sufficient mechanotransduction for endothelial maturation while maintaining compliance to support dynamic vascular morphogenesis. This work provides a mechanically tuned framework for optimizing microenvironments to balance endothelial differentiation and vascular network formation in tissue engineering and regenerative medicine.

Polysaccharides, proteins and DNA based stimulus responsive hydrogels promoting wound healing and repair: A review

The healing of various wounds remains a serious challenge in the medical field, hydrogel has high hydrophilicity and biocompatibility due to its unique network structure, which shows a strong advantage in the field of wound healing. Stimulus responsive hydrogels are particularly effective，which can control the material properties according to the external stimulus source, and provide more targeted treatment for different wounds. Here, we review physiological mechanisms of wound healing and the relationship between polysaccharides, proteins and DNA based stimulus responsive hydrogels and wound healing, materials commonly used of polysaccharides, proteins and DNA based stimulus responsive hydrogels, mechanisms of stimulus responsive hydrogels formation and network structure types, common properties of polysaccharides, proteins and DNA based stimulus responsive hydrogels for promoting wound healing and discuss their applications in medicine. Finally, the limitations and application prospects of polysaccharides, proteins and DNA based stimulus responsive hydrogels were discussed and evaluated. The review focuses on the biomedical use of polysaccharides, proteins and DNA based stimulus responsive hydrogels in wound healing and repair, and provides insights for the development of clinical related materials.

A bioactive three-layered skin substitute based on ECM components effectively promotes skin wound healing and regeneration

To overcome the limitations of conventional skin tissue engineering (TE), 3D biofabrication approaches are being developed. However, tissue mimicry should be further improved in skin models. Here, we developed and characterized biomimetic hydrogels to obtain a biofabricated three-layered (BT) skin substitute based on the main components found in the epidermal, dermal, and hypodermal skin layers. Hydrogels for dermal and hypodermal skin layers were based on a mix of agarose and type I collagen, supplemented with skin-related extracellular matrix (ECM) components (dermatan sulfate, hyaluronic acid, and elastin) and loaded with human dermal fibroblasts (hDFs) or human mesenchymal stem/stromal cells (hMSCs), respectively. The epidermal hydrogel was formulated using type I collagen supplemented with keratin and sphingolipids, and seeded with human epidermal keratinocytes (hEKs). Physicochemical results revealed adequate viscosity, gelling times, and pH for each hydrogel solution. The BT Skin also showed good swelling and degradation kinetics, and mechanical properties in a similar range of human skin. The hydrogels and BT Skin demonstrated stable cell viability and metabolic activity, as well as intercellular communication through the release of growth factors. Moreover, the BT Skin demonstrated controlled inflammation in vivo, and produced results comparable to autografting in a mouse skin wound model. This bioactive and biomimetic three-layered BT Skin has a composition that attempts to mimic the natural ECM of the skin, formulated with the characteristic cells and biomolecules present in each skin layer, and offers promising properties for its clinical application in the treatment of patients with skin injuries.

Infertility treatment using polysaccharides-based hydrogels: new strategies in tissue engineering and regenerative medicine

Infertility is a primary health issue affecting about 15% of couples of reproductive ages worldwide, leading to physical, mental, and social challenges. Advances in nanobiotechnology and regenerative medicine are opening new therapeutic horizons for infertility by developing polysaccharide-based nanostructured biomaterials. This review explores the role of tissue engineering and regenerative medicine in infertility treatment, explicitly focusing on the promising potential of polysaccharide-based hydrogels. In this context, using these biomaterials offers unique advantages, including biodegradability, biocompatibility, and the ability to mimic the natural endometrial microenvironment, making them highly effective for applications in endometrial regeneration, ovarian tissue engineering, spermatogenesis support, and controlled drug delivery. This review discusses the various properties and uses of polysaccharide-based hydrogels, like alginate, hyaluronic acid, and chitosan, in helping to restore reproductive function. While these materials hold great promise, some notable challenges to their clinical use include issues like rapid degradation, mechanical instability, and potential immune reactions. Future research should focus on developing hybrid hydrogels, investigating advanced fabrication techniques, and testing these materials in clinical settings. By combining findings from recent studies, this review aims to provide a solid foundation for researchers and clinicians looking to discover new and effective strategies for treating infertility, ultimately connecting research efforts with practical applications in healthcare.

Hyaluronan-Mediated Motility Receptor (HMMR) Overexpression Is Correlated with Poor Survival in Patients with B-ALL

Acute lymphoblastic leukemia (ALL) is a malignant neoplasm with the highest incidence in the pediatric population. Although the 5-year overall survival is greater than 85%, in emerging countries such as Mexico, the mortality rate is high. In Mexico, B-ALL is the most common type of childhood cancer; different characteristics suggest the presence of the disease; however, the prognosis is dependent on clinical and laboratory features, and no adverse prognostic molecular marker for B-ALL has yet been identified. The present research aimed to identify the prognostic value of HMMR expression in pediatric patients with B-ALL. The differential expression profile of B-ALL cells was determined via in silico analysis, and HMMR expression was subsequently measured via qRT-PCR and immunocytochemistry. The results were statistically analyzed via the ROUT test, Kolmogorov-Smirnov Z test, and Mann-Whitney U test. ROC curves and the Youden index were constructed, and Kaplan-Meier curves were plotted. We found that HMMR expression was increased in B-ALL patients (p < 0.0001). We observed that high expression was related to poor prognosis (p < 0.05). We observed that high expression was related to poor prognosis (p < 0.05). The increase in HMMR expression could be a potential early molecular prognostic marker and/or a new target in childhood B-ALL patients.

Advancements in Hyaluronic Acid Effect in Alveolar Ridge Preservation: A Narrative Review

Background/Objectives: Tooth extraction induces significant alveolar ridge dimensional changes and soft tissue modifications, often leading to challenges in implant placement or conventional prosthetic rehabilitation. Alveolar Ridge Preservation (ARP) strategies aim to mitigate post-extraction resorption of the alveolar ridge, enhancing both the quality and quantity of bone and soft tissue during healing. Hyaluronic acid (HYA) has emerged as a promising biological agent for ARP due to its osteoinductive, antimicrobial, and anti-inflammatory properties. However, the effects of HYA in ARP remain inconsistently reported. This study aims to assess current clinical and preclinical evidence regarding the biological effects of HYA and its application in ARP. Additionally, it evaluates HYA's impact-alone or in combination with other products-on hard and soft tissue dimensional changes, early wound healing, and implant success rates. Methods: A comprehensive electronic literature search was conducted, and studies meeting the inclusion criteria were critically evaluated. Relevant data were extracted from the final selection of articles. Results: Thirteen publications were evaluated. Some studies reported a significantly improved newly formed bone following ARP with intra-socket HYA application as a single approach (p = 0.004). Combining HYA with a bone graft and a free palatal graft resulted in significantly greater amounts of newly formed and mature bone, reduced clinical bone width changes, lower radiographic crestal bone loss (p < 0.01), and diminished radiological volumetric and linear bone resorption (p = 0.018). Short-term follow-up data indicated improved soft tissue healing associated with HYA-based ARP. While HYA appears to have a protective effect on ridge dimensional changes in ARP, other studies reported no significant differences in radiographic bone dimensional changes or soft tissue improvement. Conclusions: The addition of HYA to bone grafts may enhance some ARP outcomes. However, the variability in outcomes and methodologies across the evaluated studies precludes drawing definitive clinical conclusions. Further robust research is needed to clarify HYA's role in ARP. With respect to clinical significance enhancing the understanding of ARP management strategies and their effects on post-extraction sockets empowers clinicians to make more informed decisions. The knowledge of HYA effects facilitates the selection of personalized ARP approaches tailored to optimize outcomes for subsequent interventions.

A functional hydrogel dressing based on glycyrrhizic acid with low-swelling and moisturizing properties for enhancing infected wound repair

Wound healing is a challenging due to the presence of bacterial infection, excessive inflammation and angiogenesis disorders. While traditional therapies struggle, a functional hydrogel can effectively repair wounds. However, the use of hydrogels is limited due to their high swelling and excessive dehydration characteristics. Herein, an interpenetrating polymer network hydrogel (HGP@EGCG) based on hyaluronic acid methacrylate (HAMA), glycyrrhizic acid (GA), polyvinyl alcohol (PVA), epigallocatechin-3-gallate (EGCG), and glycerin/water binary solvent was developed by self-assembly, physical entanglement and chemical crosslinking for infected wound healing. GA forms a primary network through self-assembly induced by Zn2+ and HAMA forms a more robust network structure through free radical polymerization as a rigid backbone, followed by the physical entanglement of PVA, which provides additional crosslinks within the network. The robust network structure conferred the HGP hydrogel with low swelling properties. HGP@EGCG hydrogels could adhere to the wound surface, exhibiting adequate tensile and compressive strength to withstand deformations induced by external forces. Then HGP@EGCG hydrogels with good moisture retention could facilitate the maintenance of wound hydration and prolong usage. Moreover, HGP@EGCG hydrogels could release the drug rapidly in an acidic environment and eliminate bacteria. The designed hydrogels demonstrated multifaceted functionality, including suitable adhesion, low swelling, good moisture retention, and efficient antibacterial properties. Both in vitro and in vivo investigations confirmed that HGP@EGCG hydrogels had good biocompatibility and promoted human umbilical vein endothelial cell migration and tube formation, which markedly expedited wound healing. Consequently, HGP@EGCG hydrogels present a broad spectrum of potential applications in the clinical treatment of infected wounds.

Hyaluronic Acid Role in Biomaterials Prevascularization

Tissue vascularization is a major bottleneck in tissue engineering. In this review, the state of the art on the intricate role of hyaluronic acid (HA) in angiogenesis is explored. HA plays a twofold role in angiogenesis. First, when released as a free polymer in the extracellular matrix (ECM), HA acts as a signaling molecule triggering multiple cascades that foster smooth muscle cell differentiation, migration, and proliferation thereby contributing to vessel wall thickening. Simultaneously, HA bound to the plasma membrane in the pericellular space functions as a polymer block, participating in vessel formation. Starting with the HA origins in native vascular tissues, the approaches aimed at achieving vascularization in vivo are reviewed. The significance of HA molecular weight (MW) in angiogenesis and the challenges associated with utilizing HA in vascular tissue engineering (VTE) are conscientiously addressed. The review finally focuses on a thorough examination and comparison of the diverse strategies adopted to harness the benefits of HA in the vascularization of bioengineered materials. By providing a nuanced perspective on the multifaceted role of HA in angiogenesis, this review contributes to the ongoing discourse in tissue engineering and advances the collective understanding of optimizing vascularization processes assisted by functional biomaterials.

Unlocking Novel Anticancer Strategies: Bioactive Hydrogels for Local Delivery of Plasma-Derived Oxidants in an In Ovo Cancer Model

Cold atmospheric plasma (CAP) is a tool with the ability to generate reactive oxygen and nitrogen species (RONS), which can induce therapeutic effects like disinfection, wound healing, and cancer treatment. In the plasma oncology field, CAP-treated hydrogels (PTHs) are being explored for the local administration of CAP-derived RONS as a novel anticancer approach. PTHs have shown anticancer effects in vitro, however, they have not yet been studied in more relevant cancer models. In this context, the present study explores for the first time the therapeutic potential of PTHs using an advanced in ovo cancer model. PTHs composed of alginate (Alg), gelatin (Gel), Alg/Gel combination, or Alg/hyaluronic acid (HA) combination are investigated. All embryos survived the PTHs treatment, suggesting that the in ovo model could become a time- and cost-effective tool for developing hydrogel-based anticancer approaches. Results revealed a notable reduction in CD44+ cell population and their proliferative state for the CAP-treated Alg-HA condition. Moreover, the CAP-treated Alg-HA formulation alters the extracellular matrix composition, which may help combat drug-resistance. In conclusion, the present study validates the utility of in ovo cancer model for PTHs exploration and highlights the promising potential of Alg-based PTHs containing HA and CAP-derived RONS for cancer treatment.

Topical hADSCs-HA Gel Promotes Skin Regeneration and Angiogenesis in Pressure Ulcers by Paracrine Activating PPARβ/δ Pathway

Background

Pressure ulcer is common in the bedridden elderly with high mortality and lack of effective treatment. In this study, human-adipose-derived-stem-cells-hyaluronic acid gel (hADSCs-HA gel) was developed and applied topically to treat pressure ulcers, of which efficacy and paracrine mechanisms were investigated through in vivo and in vitro experiments.

Methods

Pressure ulcers were established on the backs of C57BL/6 mice and treated topically with hADSCs-HA gel, hADSCs, hyaluronic acid, and normal saline respectively. The rate of wound closure was observed continuously during the following 14 days and the wound samples were obtained for Western blot, histopathology, immunohistochemistry, and proteomic analysis. Human dermal fibroblasts (HDFs) and human venous endothelial cells (HUVECs) under normal or hypoxic conditions were treated with conditioned medium of human ADSCs (ADSC-CM), then CCK-8, scratch test, tube formation, and Western blot were conducted to evaluate the paracrine effects of hADSCs and to explore the underlying mechanism.

Results

The in vivo data demonstrated that hADSCs-HA gel significantly accelerated the healing of pressure ulcers by enhancing collagen expression, angiogenesis, and skin proliferation. The in vitro data revealed that hADSCs strengthened the proliferation and wound healing capabilities of HDFs and HUVECs, meanwhile promoted collagen secretion and tube formation through paracrine mode. ADSC-CM was also proved to exert protective effects on hypoxic HDFs and HUVECs. Besides, the results of proteomic analysis and Western blot elucidated that lipid metabolism and PPARβ/δ pathway mediated the healing effect of hADSCs-HA gel on pressure ulcers.

Conclusion

Our research showed that topical application of hADSCs-HA gel played an important role in dermal regeneration and angiogenesis. Therefore, hADSCs-HA gel exhibited the potential as a novel stem-cell-based therapeutic strategy of treating pressure ulcers in clinical practices.

Enhanced alveolar ridge preservation with hyaluronic acid-enriched allografts: a comparative study of granular allografts with and without hyaluronic acid addition

PURPOSE

Ridge preservation is essential to restore alveolar ridge volume and to enhance esthetic and functional outcomes for dental implants. The addition of hyaluronic acid to allogeneic bone substitute materials might enhance these outcomes. This clinical study evaluated the efficacy of ridge preservation after tooth extraction using granular allografts with and without hyaluronic acid addition.

METHODS

In this retrospective study, 40 patients with compromised extraction sockets were enrolled. Among them, 19 received particulate allogeneic bone substitutes (Allo), 21 received allogeneic bone substitutes with hyaluronic acid (AlloHya). Vertical and horizontal graft stability, graft shrinkage rate, and bone mineral density were assessed using radiographic measurements on CBCT scans conducted before tooth extraction, directly after ridge preservation and after four months. Patients were followed up 12 months post-implantation.

RESULTS

Vertical height loss after 4 months was significantly greater in the Allo group (-0.82 ± 0.95 mm) compared to the AlloHya group (-0.19 ± 0.51 mm; p = 0.011). Graft shrinkage rate was 16.9 ± 11.5% (Allo) and 10.3 ± 7.7% (AlloHya) (p = 0.038). After four months, average bone density was significantly higher in the AlloHya compared to the Allo group (p = 0.004). Nearly all implants (39 out of 40) were classified as "Success" according to the ICOI scheme, with no differences in implant quality between the two study groups.

CONCLUSIONS

Improved graft stability, reduced resorption, and increased bone density were observed in hyaluronic acid-enriched allografts compared to pure allografts. Adding hyaluronic acid to allogeneic bone grafts significantly enhanced outcomes in ridge preservation.

Elevated RHAMM as a biomarker for predicting diabetic kidney disease in patients with type 2 diabetes

Background

Diabetic kidney disease (DKD) poses a significant challenge globally as a complication of diabetes. Hyaluronan (HA), a critical non-sulfated glycosaminoglycan in the extracellular matrix, plays a pivotal role in the progression of DKD. This study assesses the predictive significance of HA's corresponding receptor, RHAMM (receptor for HA-mediated motility), in DKD pathogenesis in type 2 diabetes (T2DM) patients.

Methods

Enzyme-linked immunosorbent assays were utilized to measure plasma and urine levels of HA, CD44 and RHAMM in 99 diabetic patients. Immunohistochemistry staining was employed to examine HA deposition, CD44 and RHAMM expressions from 18 biopsy-proven DKD patients. Spearman correlation analysis, linear regression and receiver operating characteristic (ROC) analysis were conducted to establish associations between plasma HA, CD44 and RHAMM levels, and clinical parameters in DKD patients with T2DM.

Results

Elevated plasma and urine HA, CD44 and RHAMM levels were notably observed in the severe renal dysfunction group. Plasma RHAMM exhibited positive correlations with HA (r = 0.616, P < .001) and CD44 (r = 0.220, P < .001), and a negative correlation with estimated glomerular filtration rate (eGFR) (r = -0.618, P < .001). After adjusting for other potential predictors, plasma RHAMM emerged as an independent predictor of declining eGFR (β = -0.160, P < .05). Increased HA, CD44 and RHAMM levels in kidney biopsies of DKD patients were closely associated with heightened kidney injury. The ROC curve analysis highlighted an area under the curve (AUC) of 0.876 for plasma RHAMM, indicating superior diagnostic efficacy compared to CD44 in predicting DKD pathogenesis. The combined AUC of 0.968 for plasma RHAMM, HA and CD44 also suggested even greater diagnostic potential for DKD pathogenesis.

Conclusion

These findings provide initial evidence that elevated RHAMM levels predict DKD pathogenesis in T2DM patients. The formation of a triple complex involving HA, CD44 and RHAMM on the cell surface shows promise as a targetable biomarker for early intervention to mitigate severe renal dysfunctions.

Phototuning of Hyaluronic-Acid-Based Hydrogel Properties to Control Network Formation in Human Vascular Endothelial Cells

In vitro network formation by endothelial cells serves as a fundamental model for studies aimed at understanding angiogenesis. The morphogenesis of these cells to form a network is intricately regulated by the mechanical and biochemical properties of the extracellular matrix. Here the effects of modulating these properties in hydrogels derived from phenolated hyaluronic acid (HA-Ph) and phenolated gelatin (Gelatin-Ph) are presented. Visible-light irradiation in the presence of tris(2,2'-bipyridyl)ruthenium(II) chloride hexahydrate and sodium persulfate induces the crosslinking of these polymers, thereby forming a hydrogel and degrading HA-Ph. Human vascular endothelial cells form networks on the hydrogel prepared by visible-light irradiation for 45 min (42 W cm-2 at 450 nm) but not on the hydrogels prepared by irradiation for 15, 30, or 60 min. The irradiation time-dependent degradation of HA-Ph and the changes in the mechanical stiffness of the hydrogels, coupled with the expressions of RhoA and β-actin genes and CD44 receptors in the cells, reveal that the network formation is synergistically influenced by the hydrogel stiffness and HA-Ph degradation. These findings highlight the potential of tailoring HA-based hydrogel properties to modulate human vascular endothelial cell responses, which is critical for advancing their application in vascular tissue engineering.

Hyaluronic Acid Interacting Molecules Mediated Crosstalk between Cancer Cells and Microenvironment from Primary Tumour to Distant Metastasis

Hyaluronic acid (HA) is a prominent component of the extracellular matrix, and its interactions with HA-interacting molecules (HAIMs) play a critical role in cancer development and disease progression. This review explores the multifaceted role of HAIMs in the context of cancer, focusing on their influence on disease progression by dissecting relevant cellular and molecular mechanisms in tumour cells and the tumour microenvironment. Cancer progression can be profoundly affected by the interactions between HA and HAIMs. They modulate critical processes such as cell adhesion, migration, invasion, and proliferation. The TME serves as a dynamic platform in which HAIMs contribute to the formation of a unique niche. The resulting changes in HA composition profoundly influence the biophysical properties of the TME. These modifications in the TME, in conjunction with HAIMs, impact angiogenesis, immune cell recruitment, and immune evasion. Therefore, understanding the intricate interplay between HAIMs and HA within the cancer context is essential for developing novel therapeutic strategies. Targeting these interactions offers promising avenues for cancer treatment, as they hold the potential to disrupt critical aspects of disease progression and the TME. Further research in this field is imperative for advancing our knowledge and the treatment of cancer.

Bioarchitectural Design of Bioactive Biopolymers: Structure-Function Paradigm for Diabetic Wound Healing

Chronic wounds such as diabetic ulcers are a major complication in diabetes caused by hyperglycemia, prolonged inflammation, high oxidative stress, and bacterial bioburden. Bioactive biopolymers have been found to have a biological response in wound tissue microenvironments and are used for developing advanced tissue engineering strategies to enhance wound healing. These biopolymers possess innate bioactivity and are biodegradable, with favourable mechanical properties. However, their bioactivity is highly dependent on their structural properties, which need to be carefully considered while developing wound healing strategies. Biopolymers such as alginate, chitosan, hyaluronic acid, and collagen have previously been used in wound healing solutions but the modulation of structural/physico-chemical properties for differential bioactivity have not been the prime focus. Factors such as molecular weight, degree of polymerization, amino acid sequences, and hierarchical structures can have a spectrum of immunomodulatory, anti-bacterial, and anti-oxidant properties that could determine the fate of the wound. The current narrative review addresses the structure-function relationship in bioactive biopolymers for promoting healing in chronic wounds with emphasis on diabetic ulcers. This review highlights the need for characterization of the biopolymers under research while designing biomaterials to maximize the inherent bioactive potency for better tissue regeneration outcomes, especially in the context of diabetic ulcers.

The Tumor Stroma of Squamous Cell Carcinoma: A Complex Environment That Fuels Cancer Progression

The tumor microenvironment (TME), a complex assembly of cellular and extracellular matrix (ECM) components, plays a crucial role in driving tumor progression, shaping treatment responses, and influencing metastasis. This narrative review focuses on the cutaneous squamous cell carcinoma (cSCC) tumor stroma, highlighting its key constituents and their dynamic contributions. We examine how significant changes within the cSCC ECM-specifically, alterations in fibronectin, hyaluronic acid, laminins, proteoglycans, and collagens-promote cancer progression, metastasis, and drug resistance. The cellular composition of the cSCC TME is also explored, detailing the intricate interplay of cancer-associated fibroblasts (CAFs), mesenchymal stem cells (MSCs), endothelial cells, pericytes, adipocytes, and various immune cell populations. These diverse players modulate tumor development, angiogenesis, and immune responses. Finally, we emphasize the TME's potential as a therapeutic target. Emerging strategies discussed in this review include harnessing the immune system (adoptive cell transfer, checkpoint blockade), hindering tumor angiogenesis, disrupting CAF activity, and manipulating ECM components. These approaches underscore the vital role that deciphering TME interactions plays in advancing cSCC therapy. Further research illuminating these complex relationships will uncover new avenues for developing more effective treatments for cSCC.

In silico validation of hyaluronic acid - drug conjugates based targeted drug delivery for the treatment of COVID-19

The impact of COVID-19 urges scientists to develop targeted drug delivery to manage Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) viral infections with a fast recovery rate. The aim of the study is to develop Hyaluronic Acid (HA) drug conjugates of viral drugs to target two important enzymes (Mpro and PLpro) of SARS-CoV-2. Three antiviral drugs, namely Dexamethasone (DEX), Favipiravir (FAV), and Remdesivir (REM), were chosen for HA conjugation due to their reactive functional groups. Free forms of drugs (DEX, FAV, REM) and HA drug conjugates (HA-DEX, HA-FAV, HA-REM, HA-RHA, HA-RHE) were validated against Mpro (PDB ID 6LU7) and PLpro (PDB 7LLZ), which play an essential role in the replication and reproduction of the SARS-CoV-2 virus. The results of the present study revealed that HA-drug conjugates possess higher binding affinity and the best docking score towards the Mpro and PLpro target proteins of SARS-CoV-2 than their free forms of drugs. ADMET screening resulted that HA-drug conjugates exhibited better pharmacokinetic profiles than their pure forms of drugs. Further, molecular dynamic simulation studies, essential dynamics and free energy landscape analyses show that HA antiviral drug conjugates possess good trajectories and energy status, with the PLpro target protein (PDB 7LLZ) of SARS-CoV-2 through long-distance (500 ns) simulation screening. The research work recorded the best drug candidate for Cell-Targeted Drug Delivery (CTDD) for SARS-CoV-2-infected cells through hyaluronic acid conjugates of antiviral drugs.

The Paracrine Effect of Hyaluronic Acid-Treated Endothelial Cells Promotes BMP-2-Mediated Osteogenesis

The combination of hyaluronic acid (HA) and BMP-2 has been reported to promote bone regeneration. However, the interaction of endothelial cells and bone marrow mesenchymal stem cells (BMSCs) during HA + BMP-2 treatment is not fully understood. This study aimed to analyze the direct effect of HA, as well as the paracrine effect of HA-treated endothelial cells, on the BMP-2-mediated osteogenic differentiation of BMSCs. The angiogenic differentiation potential of HA at different molecular weights and different concentrations was tested. The direct effect of HA, as well as the indirect effect of HA-treated human umbilical cord endothelial cells (HUVECs, i.e., conditioned medium (CM)-based co-culture) on the BMP-2-mediated osteogenic differentiation of BMSCs was analyzed using alkaline phosphatase (ALP) staining and activity, alizarin red S (ARS) staining, and RT-qPCR of osteogenic markers. Angiogenic differentiation markers were also analyzed in HUVECs after treatment with HA + BMP-2. The bone regeneration potential of BMP-2 and HA + BMP-2 was analyzed in a rat ectopic model. We found that 1600 kDa HA at 300 µg/mL promoted tube formation by HUVECs in vitro and upregulated the mRNA expression of the angiogenic markers CD31, VEGF, and bFGF. HA inhibited, but conditioned medium from HA-treated HUVECs promoted, the BMP-2-mediated osteogenic differentiation of BMSCs, as indicated by the results of ALP staining and activity, ARS staining, and the mRNA expression of the osteogenic markers RUNX-2, ALP, COLI, and OPN. HA + BMP-2 (50 ng/mL) upregulated the expression of the angiogenesis-related genes VEGF and bFGF in HUVECs and bone regeneration in vivo compared to BMP-2 treatment. In conclusion, the paracrine effect of hyaluronic acid-treated endothelial cells promotes BMP-2-mediated osteogenesis, suggesting the application potential of HA + BMP-2 in bone tissue engineering.

The optimal dosage of hyaluronic acid for bone regeneration in rat calvarial defects

PURPOSE

Hyaluronic acid (HA) affects angiogenesis and promotes the migration and differentiation of mesenchymal cells, thereby activating the osteogenic ability of osteoblasts. Although studies on the action of HA during bone regeneration are being actively conducted, the optimal dose of HA required for bone regeneration remains unclear. Therefore, the purpose of this study was to elucidate the most effective HA dose for bone formation using a rat critical-size defect model.

METHODS

Thirty rats were randomly divided into 5 groups, with 6 rats in each group. An absorbable collagen sponge soaked with HA or saline was used to fill an 8-mm defect, which was then covered with a collagen membrane. Different treatments were performed for each group as follows: (1) saline control, (2) 1 mg/mL HA, (3) 25 mg/mL HA, (4) 50 mg/mL HA, or (5) 75 mg/mL HA. After a healing period of 4 weeks, micro-computed tomography and histological analysis were performed. The obtained values were analyzed using analysis of variance and the Tukey test (P<0.05).

RESULTS

At week 4, the 75 mg/mL HA group had the highest bone volume/total volume ratio, new bone, and bone fill among the 5 groups, and these values were significantly different from those observed in the control group (P<0.01) and 1 mg/mL HA group (P<0.001). More active bone formation was observed in the higher-dose HA groups (25 mg/mL, 50 mg/mL, and 75 mg/mL HA), which included a large amount of woven bone.

CONCLUSIONS

The 75 mg/mL HA group showed better bone formation than the other groups (1, 25, and 50 mg/mL HA and control).

Biological Macromolecule-Based Scaffolds for Urethra Reconstruction

Urethral reconstruction strategies are limited with many associated drawbacks. In this context, the main challenge is the unavailability of a suitable tissue that can endure urine exposure. However, most of the used tissues in clinical practices are non-specialized grafts that finally fail to prevent urine leakage. Tissue engineering has offered novel solutions to address this dilemma. In this technology, scaffolding biomaterials characteristics are of prime importance. Biological macromolecules are naturally derived polymers that have been extensively studied for various tissue engineering applications. This review discusses the recent advances, applications, and challenges of biological macromolecule-based scaffolds in urethral reconstruction.

Weaving the nest: extracellular matrix roles in pre-metastatic niche formation

The discovery that primary tumors condition distant organ sites of future metastasis for seeding by disseminating tumor cells through a process described as the pre-metastatic niche (PMN) formation revolutionized our understanding of cancer progression and opened new avenues for therapeutic interventions. Given the inherent inefficiency of metastasis, PMN generation is crucial to ensure the survival of rare tumor cells in the otherwise hostile environments of metastatic organs. Early on, it was recognized that preparing the "soil" of the distal organ to support the outgrowth of metastatic cells is the initiating event in PMN development, achieved through the remodeling of the organ's extracellular matrix (ECM). Remote restructuring of ECM at future sites of metastasis under the influence of primary tumor-secreted factors is an iterative process orchestrated through the crosstalk between resident stromal cells, such as fibroblasts, epithelial and endothelial cells, and recruited innate immune cells. In this review, we will explore the ECM changes, cellular effectors, and the mechanisms of ECM remodeling throughout PMN progression, as well as its impact on shaping the PMN and ultimately promoting metastasis. Moreover, we highlight the clinical and translational implications of PMN ECM changes and opportunities for therapeutically targeting the ECM to hinder PMN formation.

Optimizing phenol-modified hyaluronic acid for designing shape-maintaining biofabricated hydrogel scaffolds in soft tissue engineering

In this study, we developed a well-printable biomaterial ink for 3D printing of shape-maintaining hydrogel scaffolds. The hydrogel base comprised tyramine-modified hyaluronic acid (HA-Tyr) and gelatin methacrylate (GelMA) and was dually cross-linked. Using the Box-Behnken design, we explored how varying the ink composition affected fiber formation and shape preservation. By adjusting the polymer ratios, we produced a stable hydrogel with varying responses, from a viscous liquid to a thick gel, and optimized 3D scaffolds that were structurally stable both during and after printing, offering precision and flexibility. Our ink exhibited shear-thinning behavior and high swelling capacity, as well as ECM-like characteristics and biocompatibility, making it an ideal candidate for soft tissues matrices with storage modulus of around 300 Pa. Animal trials and CAM assays confirmed its biocompatibility and integration with host tissue.

The interplay of cells, polymers, and vascularization in three-dimensional lung models and their applications in COVID-19 research and therapy

Millions of people have been affected ever since the emergence of the corona virus disease of 2019 (COVID-19) outbreak, leading to an urgent need for antiviral drug and vaccine development. Current experimentation on traditional two-dimensional culture (2D) fails to accurately mimic the in vivo microenvironment for the disease, while in vivo animal model testing does not faithfully replicate human COVID-19 infection. Human-based three-dimensional (3D) cell culture models such as spheroids, organoids, and organ-on-a-chip present a promising solution to these challenges. In this report, we review the recent 3D in vitro lung models used in COVID-19 infection and drug screening studies and highlight the most common types of natural and synthetic polymers used to generate 3D lung models.

VEGF-Encoding, Gene-Activated Collagen-Based Matrices Promote Blood Vessel Formation and Improved Wound Repair

Disruption in vascularization during wound repair can severely impair healing. Proangiogenic growth factor therapies have shown great healing potential; however, controlling growth factor activity and cellular behavior over desired healing time scales remains challenging. In this study, we evaluated collagen-mimetic peptide (CMP) tethers for their capacity to control growth factor gene transfer and growth factor activity using our recently developed gene-activated hyaluronic acid-collagen matrix (GAHCM). GAHCM was comprised of DNA/polyethyleneimine (PEI) polyplexes that were retained on hyaluronic acid (HA)-collagen hydrogels using CMPs. We hypothesized that using CMP-collagen tethers to control vascular endothelial growth factor-A (VEGF-A) gene delivery in fibroblasts would provide a powerful strategy to modulate the proangiogenic behaviors of endothelial cells (ECs) for blood vessel formation, resulting in enhanced wound repair. In co-culture experiments, we observed that CMP-modified GAHCM induced tunable gene delivery in fibroblasts as predicted, and correspondingly, VEGF-A produced by the fibroblasts led to increased growth and persistent migration of ECs for at least 7 days, as compared to non-CMP-modified GAHCM. Moreover, when ECs were exposed to fibroblast-containing VEGF-GAHCM with higher levels of CMP modification (50% CMP-PEI, or 50 CP), high CD31 expression was stimulated, resulting in the formation of an interconnected EC network with a significantly higher network volume and a larger diameter network structure than controls. Application of VEGF-GAHCM with 50 CP in murine splinted excisional wounds facilitated prolonged prohealing and proangiogenic responses resulting in increased blood vessel formation, improved granulation tissue formation, faster re-epithelialization, and overall enhanced repair. These findings suggest the benefits of CMP-collagen tethers as useful tools to control gene transfer and growth factor activity for improved treatment of wounds.

Crosstalk between myofibroblasts and macrophages: A regulative factor of valvular fibrosis in calcific aortic valve disease

Inflammation and fibrosis are highly correlated with the progression of calcific aortic valve disease (CAVD). As one of the differentiated forms of valvular interstitial cells, myofibroblasts play a critical role in CAVD's development as do macrophages. Although numerous studies have been conducted on them separately, their communication and interaction remain unclear. We used porcine aortic valves to isolate valve interstitial cells (VICs). VICs were induced to differentiate into myofibroblasts by transforming growth factor-β1 (TGF-β1). After successful activation was determined, the myofibroblast-conditioned medium (CM) was collected and used to act on RAW264.7, a macrophage cell line. A migration and adhesion assay estimated the recruitment capability of myofibroblasts on macrophages. We used flow cytometry, quantitative polymerase chain reaction (qPCR), and Western blot analysis to investigate myofibroblasts' polarity promotion function in macrophages. Finally, we used macrophage-CM on VICs to explore the differentiation induction function of polarized macrophages. Myofibroblast marker alpha-smooth muscle actin and M2 macrophage marker CD163 were detected as upregulated in CAVD patients, and their expression has a certain correlation. The Smad3/HA/CD44 axis activated the differentiation of myofibroblasts by Western blot. The myofibroblast-CM can promote chemotaxis and adhesion of macrophages through protein kinase B/chemokine (C-C motif) ligand5 and Smad3/HA/CD44, respectively. Hyaluronic acid (HA) inside the myofibroblast-CM stimulates macrophages to polarize into M2 macrophages. In turn, M2 macrophage-CM has the promotive ability to activate myofibroblasts but fails to induce the osteoblast differentiation of VICs directly. The crosstalk between myofibroblasts and macrophages causes the excessive activation of myofibroblasts. This positive feedback loop may play a vital role in CAVD progression.

Hyaluronan Receptors as Mediators and Modulators of the Tumor Microenvironment

The tumor microenvironment (TME) is a dynamic and complex matter shaped by heterogenous cancer and cancer-associated cells present at the tumor site. Hyaluronan (HA) is a major TME component that plays pro-tumorigenic and carcinogenic functions. These functions are mediated by different hyaladherins expressed by cancer and tumor-associated cells triggering downstream signaling pathways that determine cell fate and contribute to TME progression toward a carcinogenic state. Here, the interaction of HA is reviewed with several cell-surface hyaladherins-CD44, RHAMM, TLR2 and 4, LYVE-1, HARE, and layilin. The signaling pathways activated by these interactions and the respective response of different cell populations within the TME, and the modulation of the TME, are discussed. Potential cancer therapies via targeting these interactions are also briefly discussed.

The importance of RHAMM in the normal brain and gliomas: physiological and pathological roles

Although the literature about the functions of hyaluronan and the CD44 receptor in the brain and brain tumours is extensive, the role of the receptor for hyaluronan-mediated motility (RHAMM) in neural stem cells and gliomas remain poorly explored. RHAMM is considered a multifunctional receptor which performs various biological functions in several normal tissues and plays a significant role in cancer development and progression. RHAMM was first identified for its ability to bind to hyaluronate, the extracellular matrix component associated with cell motility control. Nevertheless, additional functions of this protein imply the interaction with different partners or cell structures to regulate other biological processes, such as mitotic-spindle assembly, gene expression regulation, cell-cycle control and proliferation. In this review, we summarise the role of RHAMM in normal brain development and the adult brain, focusing on the neural stem and progenitor cells, and discuss the current knowledge on RHAMM involvement in glioblastoma progression, the most aggressive glioma of the central nervous system. Understanding the implications of RHAMM in the brain could be useful to design new therapeutic approaches to improve the prognosis and quality of life of glioblastoma patients.

A combined subcision approach with either fractional CO2 laser (10,600 nm) or cross-linked hyaluronic acid versus subcision alone in atrophic post-acne scar treatment

Different treatment options for post-acne scars exist, but with varying clinical efficacy, side effects, and prolonged downtime. This study aims to compare the efficacy and safety of combined subcision with either fractional CO2 laser or cross-linked hyaluronic acid filler (HA) versus subcision alone in the treatment of facial atrophic post-acne scars. Forty patients with atrophic post-acne scars were subjected to subcision on both sides of the face, then were randomly divided into three groups. Group I (20 patients): subcision combined with cross-linked HA filler injection at one side of the face; group II (20 patients): subcision followed by fractional CO2 at the other side of the face; and group III (20 patients): with subcision only as a control group. Treatment sessions were every month until clinical improvement or for maximum three sessions. The treatment's efficacy was assessed by Goodman and Baron's qualitative and quantitative grading systems. The two blinded investigator scores showed significant improvement in both the filler side versus subcision (p value = 0.015), and the fractional laser side versus subcision (p value < 0.001), with no statistically significant difference between both sides (p value = 0.171). Qualitative grading by Goodman and Baron scores showed that the percentage of patients with excellent improvement was higher in group 1 and group 2 than in group 3 with p value = 0.031; also the mean percentage of reduction in quantitative grading was higher in group 1 and group 2 than in group 3 with p value < 0.00. Either combined subcision with fractional CO2 laser or with cross-linked HA filler achieved superior improvement in facial atrophic post acne scars treatment with no serious side effects in this study. However, subcision only by blunt canula also had modest improvement.

Macrocyclic Supramolecular Assemblies Based on Hyaluronic Acid and Their Biological Applications

Hyaluronic acid (HA), which contains multiple carboxyl, hydroxyl, and acetylamino groups and is an agent that targets tumors, has drawn great attention in supramolecular diagnosis and treatment research. It can not only assemble directly with macrocyclic host-guest complexes through hydrogen bonding and electrostatic interactions but also can be modified with macrocyclic compounds or functional guest molecules by an amidation reaction and used for further assembly. Macrocycles play a main role in the construction of supramolecular drug carriers, targeted imaging agents, and hydrogels, such as cyclodextrins and cucurbit[n]urils, which can encapsulate photosensitizers, drugs, or other functional guest molecules via host-guest interactions. Therefore, the formed supramolecular assemblies can respond to various stimuli, such as enzymes, light, electricity, and magnetism for controlled drug delivery, enhance the luminescence intensity of the assembly, and improve drug loading capacity. In addition, the nanosupramolecular assembly formed with HA can also improve the biocompatibility of drugs, reduce drug toxicity and side effects, and enhance cell permeability; thus, the assembly has extensive application value in biomedical research. This Account mainly focuses on macrocyclic supramolecular assemblies based on HA, especially their biological applications and progress in the field, and these assemblies include (i) guest-modified HA, such as pyridinium-, adamantane-, peptide-, and other functional-group-modified HA, along with their cyclodextrin and cucurbit[n]uril assemblies; (ii) macrocycle-modified HA, such as HA modified with cyclodextrins and cucurbit[n]uril derivatives and their assembly with various guests; (iii) direct assembly between unmodified HA and cyclodextrin- or cucurbit[n]uril-based host-guest complexes. Particularly, we discussed the important role of macrocyclic host-guest complexes in HA-based supramolecular assembly, and the roles included improving the water solubility and efficacy of hydrophobic drugs, enhancing the luminescent intensity of assemblies, inducing room temperature phosphorescence and providing energy transfer systems, constructing multi-stimulus-responsive supramolecular assemblies, and in situ formation of hydrogels. Additionally, we believe that obtaining in-depth knowledge of these HA-based macrocyclic supramolecular assemblies and their biological applications encompasses many challenges regarding drug carriers, targeted imaging agents, wound healing, and biomedical soft materials and would certainly contribute to the rapid development of supramolecular diagnosis and treatment.

Human Umbilical Vein Endothelial Cells Form a Network on a Hyaluronic Acid/Gelatin Composite Hydrogel Moderately Crosslinked and Degraded by Hydrogen Peroxide

The study of the capillary-like network formation of human umbilical vein endothelial cells (HUVECs) in vitro is important for understanding the factors that promote or inhibit angiogenesis. Here, we report the behavior of HUVECs on the composite hydrogels containing hyaluronic acid (HA) and gelatin with different degrees of degradation, inducing the different physicochemical properties of the hydrogels. The hydrogels were obtained through horseradish peroxidase (HRP)-catalyzed hydrogelation consuming hydrogen peroxide (H₂O₂, 16 ppm) supplied from the air, and the degradation degree was tuned by altering the exposure time to the air. The HUVECs on the composite hydrogel with intermediate stiffness (1.2 kPa) obtained through 120 min of the exposure were more elongated than those on the soft (0.4 kPa) and the stiff (2.4 kPa) composite hydrogels obtained through 15 min and 60 min of the exposure, respectively. In addition, HUVECs formed a capillary-like network only on the stiff composite hydrogel although those on the hydrogels with comparable stiffness but containing gelatin alone or alginate instead of HA did not form the network. These results show that the HA/gelatin composite hydrogels obtained through the H₂O₂-mediated crosslinking and degradation could be a tool for studies using HUVECs to understand the promotion and inhibition of angiogenesis.

The role of hyaluronic acid in polidocanol foam: An in vitro study

Objective

To study the role of hyaluronic acid (HA) in polidocanol (POL) foam.

Methods

The dose-dependent effect of HA-POL on cultured human umbilical vein endothelial cells (HUVECs) as well as foam stability was evaluated by measuring optical density (OD) values and foam half-life time (FHT), respectively. An in vitro model was utilized for estimating the foam blood-displacement capacity by adopting maximum displacement distance (MDD) and displacement time. A comparison of foam viscosity was also carried out.

Results

The OD values of HUVECs treated with HA first increased and then decreased with the growing dosage of HA while cells treated with HA-POL died. Both FHT and displacement time were prolonged statistically with a gradually enhanced foam viscosity. As to MDD, there were no significant differences.

Conclusions

HA was found to promote HUVECs proliferation slightly, but this was almost negligible when compared to the cell-killing capacity of 1% POL. The viscosity of POL foam was enhanced by HA indicating its positive correlation with both stability and displacement capacity of POL foam.

The role of RHAMM in cancer: Exposing novel therapeutic vulnerabilities

Receptor for hyaluronic acid-mediated motility (RHAMM) is a cell surface receptor for hyaluronic acid that is critical for cell migration and a cell cycle protein involved in microtubule assembly and stability. These functions of RHAMM are required for cellular stress responses and cell cycle progression but are also exploited by tumor cells for malignant progression and metastasis. RHAMM is often overexpressed in tumors and is an independent adverse prognostic factor for a number of cancers such as breast and prostate. Interestingly, pharmacological or genetic inhibition of RHAMM in vitro and in vivo ablates tumor invasiveness and metastatic spread, implicating RHAMM as a potential therapeutic target to restrict tumor growth and improve patient survival. However, RHAMM’s pro-tumor activity is dependent on its subcellular distribution, which complicates the design of RHAMM-directed therapies. An alternative approach is to identify downstream signaling pathways that mediate RHAMM-promoted tumor aggressiveness. Herein, we discuss the pro-tumoral roles of RHAMM and elucidate the corresponding regulators and signaling pathways mediating RHAMM downstream events, with a specific focus on strategies to target the RHAMM signaling network in cancer cells.

Various Coated Barrier Membranes for Better Guided Bone Regeneration: A Review

A good barrier membrane is one of the important factors for effective guided bone/tissue regeneration (GBR/GTR) in the case of periodontal bone defects. Several methods are being discussed to overcome and improve the shortcomings of commercially available membranes. One of the methods is to coat the membrane with bioactive materials. In this study, 41 studies related to coated membranes for GBR/GTR published in the last 5 years were reviewed. These studies reported coating the membrane with various bioactive materials through different techniques to improve osteogenesis, antimicrobial properties, and physical/mechanical properties. The reported studies have been classified and discussed based on the purpose of coating. The goal of the most actively studied research on coating or surface modification of membranes is to improve new bone formation. For this purpose, calcium phosphate, bioactive glass, polydopamine, osteoinduced drugs, chitosan, platelet-rich fibrin, enamel matrix derivatives, amelotin, hyaluronic acid, tantalum, and copper were used as membrane coating materials. The paradigm of barrier membranes is changing from only inert (or biocompatible) physical barriers to bioactive osteo-immunomodulatory for effective guided bone and tissue regeneration. However, there is a limitation that there exists only a few clinical studies on humans to date. Efforts are needed to implement the use of coated membranes from the laboratory bench to the dental chair unit. Further clinical studies are needed in the patients’ group for long-term follow-up to confirm the effect of various coating materials.

Hyaluronan network: a driving force in cancer progression

Hyaluronan is one of the most abundant macromolecules of the extracellular matrix and regulates several physiological cell and tissue properties. However, hyaluronan has been shown to accumulate together with its receptors in various cancers. In tumors, accumulation of hyaluronan system components (hyaluronan synthesizing/degrading enzymes and interacting proteins) associates with poor outcomes of the patients. In this article, we review the main roles of hyaluronan in normal physiology and cancer, and further discuss the targeting of hyaluronan system as an applicable therapeutic strategy.

Molecular insights of hyaluronic acid - ethambutol and hyaluronic acid - isoniazid drug conjugates act as promising novel drugs for the treatment of tuberculosis

The present study examines cellular targeted drug delivery (CTDD) pattern of two novel Hyaluronic acid (HA) Tuberculosis Drug (TB) conjugates and its efficacy and strong binding affinity towards TB molecular protein targets. Two TB drugs ethambutol (EB) and isoniazid (IN) and their Hyaluronic acid conjugates (HA-EB & HA-IN) were tested for its metabolism, toxicity and excretion prediction through In silico tools they revealed hyaluronic acid conjugate of two TB drugs exhibited good drug profile over their free form of TB drugs. Further these four molecules subjected to In silico molecular docking study with four potential Mycobacterium tuberculosis target proteins (3PD8, 4Y0L, 5DZK and 6GAU). Molecular docking study revealed that hyaluronic conjugates (HA-EB & HA-IN) exhibit significant binding affinity and excellent docking scores with all screened molecular protein targets of TB over their free form of drug. Further molecular dynamic simulation was calculated for the four drug molecules (EB, IN, HA- EB & HA-IN) with DNA gyrase enzyme (PDB ID 6GAU) of Mycobacterium tuberculosis and the MDS results revealed that both the conjugates with the TB target protein possessed good number of interaction with binding pocket residues and good simulation scores than the free form of drugs.Communicated by Ramaswamy H. Sarma.

Assembly of skin substitute by cross-linking natural biomaterials on synthetic biodegradable porous mat for critical-size full-thickness burn wound regeneration

Human skin architecture comprises several interpenetrating macromolecules seen as organized extracellular matrix (ECM). For regeneration of critical-size acute and chronic wounds, substituting the damaged tissue with artificially assembled biomolecules offer an interactivemilieu. This study reports development and preclinical evaluation of a biodegradable and immuno-compatible scaffold for regeneration of critical-size (4 × 4 cm²) full-thickness rabbit burn wounds. The designed wound care product comprises synthetic terpolymer poly(L-Lactide-co-Glycolide-co-Caprolactone) (PLGC), human clinical-grade fibrin (FIB), and hyaluronic acid (HA), termed as PLGCFIBHA. Here, clotting of fibrinogen concentrate (FC) with excess thrombin in the scaffold create an interpenetrating FIB network harnessed with adhesive molecules like fibronectin and laminin present in FC with exogenous HA to produce ECM-likemilieuon porous PLGC. Penetrating into porous PLGCFIBHA, long term study showed a regulated fibroblast growth resulting in non-fibrotic dermal-like tissuein vitro. The freeze-dried PLGCFIBHA with residual thrombin facilitated suture-less, hemostatic matrix adhesion to the wound bedin vivo. By 28 d, mature and scar-less epidermis-dermis formation with skin appendages was evident in the PLGCFIBHA-treated wound area. Both negative (untreated/sham) and positive (commercial matrix-treated) control wounds showed incomplete regeneration. The PLGCFIBHA-treated wounds were comparable to native skin by 56 d. These regenerative outcomes upon single application of PLGCFIBHA confirms its potential translational value for wound care.

Recent Advances in Synthetic and Natural Biomaterials-Based Therapy for Bone Defects

Synthetic and natural biomaterials are a promising alternative for the treatment of critical-sized bone defects. Several parameters such as their porosity, surface, and mechanical properties are extensively pointed out as key points to recapitulate the bone microenvironment. Many biomaterials with this pursuit are employed to provide a matrix, which can supply the specific environment and architecture for an adequate bone growth. Nevertheless, some queries remain unanswered. This review discusses the recent advances achieved by some synthetic and natural biomaterials to mimic the native structure of bone and the manufacturing technology applied to obtain biomaterial candidates. The focus of this review is placed in the recent advances in the development of biomaterial-based therapy for bone defects in different types of bone. In this context, this review gives an overview of the potentialities of synthetic and natural biomaterials: polyurethanes, polyesters, hyaluronic acid, collagen, titanium, and silica as successful candidates for the treatment of bone defects.

Immuno-modulatory biomaterials as anti-inflammatory therapeutics

Biocompatible and biodegradable biomaterials are used extensively in regenerative medicine and serve as a tool for tissue replacement, as a platform for regeneration of injured tissue, and as a vehicle for delivery of drugs. One of the key factors that must be addressed in developing successful biomaterial-based therapeutics is inflammation. Whilst inflammation is initially essential for wound healing; bringing about clearance of debris and infection, prolonged inflammation can result in delayed wound healing, rejection of the biomaterial, further tissue damage and increased scarring and fibrosis. In this context, the choice of biomaterial must be considered carefully to minimise further induction of inflammation. Here we address the ability of the biomaterials themselves to modulate inflammatory responses and outline how the physico-chemical properties of the materials impact on their pro and anti-inflammatory properties (Fig. 1).

Nano-Sized Extracellular Matrix Particles Lead to Therapeutic Improvement for Cutaneous Wound and Hindlimb Ischemia

Cell-derived matrix (CDM) has proven its therapeutic potential and been utilized as a promising resource in tissue regeneration. In this study, we prepared a human fibroblast-derived matrix (FDM) by decellularization of in vitro cultured cells and transformed the FDM into a nano-sized suspended formulation (sFDM) using ultrasonication. The sFDM was then homogeneously mixed with Pluronic F127 and hyaluronic acid (HA), to effectively administer sFDM into target sites. Both sFDM and sFDM containing hydrogel (PH/sFDM) were characterized via immunofluorescence, sol–gel transition, rheological analysis, and biochemical factors array. We found that PH/sFDM hydrogel has biocompatible, mechanically stable, injectable properties and can be easily administered into the external and internal target regions. sFDM itself holds diverse bioactive molecules. Interestingly, sFDM-containing serum-free media helped maintain the metabolic activity of endothelial cells significantly better than those in serum-free condition. PH/sFDM also promoted vascular endothelial growth factor (VEGF) secretion from monocytes in vitro. Moreover, when we evaluated therapeutic effects of PH/sFDM via the murine full-thickness skin wound model, regenerative potential of PH/sFDM was supported by epidermal thickness, significantly more neovessel formation, and enhanced mature collagen deposition. The hindlimb ischemia model also found some therapeutic improvements, as assessed by accelerated blood reperfusion and substantially diminished necrosis and fibrosis in the gastrocnemius and tibialis muscles. Together, based on sFDM holding a strong therapeutic potential, our engineered hydrogel (PH/sFDM) should be a promising candidate in tissue engineering and regenerative medicine.

Single-Cell Microgels for Diagnostics and Therapeutics

Cell encapsulation within hydrogel droplets is transforming what is feasible in multiple fields of biomedical science such as tissue engineering and regenerative medicine, in vitro modeling, and cell-based therapies. Recent advances have allowed researchers to miniaturize material encapsulation complexes down to single-cell scales, where each complex, termed a single-cell microgel, contains only one cell surrounded by a hydrogel matrix while remaining <100 μm in size. With this achievement, studies requiring single-cell resolution are now possible, similar to those done using liquid droplet encapsulation. Of particular note, applications involving long-term in vitro cultures, modular bioinks, high-throughput screenings, and formation of 3D cellular microenvironments can be tuned independently to suit the needs of individual cells and experimental goals. In this progress report, an overview of established materials and techniques used to fabricate single-cell microgels, as well as insight into potential alternatives is provided. This focused review is concluded by discussing applications that have already benefited from single-cell microgel technologies, as well as prospective applications on the cusp of achieving important new capabilities.

Photoreactive hydrogel stiffness influences volumetric muscle loss repair

Volumetric muscle loss (VML) injuries are characterized by permanent loss of muscle mass, structure, and function. Hydrogel biomaterials provide an attractive platform for skeletal muscle tissue engineering due to the ability to easily modulate their biophysical and biochemical properties to match a range of tissue characteristics. In this work we successfully developed a mechanically tunable hyaluronic acid (HA) hydrogel system to investigate the influence of hydrogel stiffness on VML repair. HA was functionalized with photoreactive norbornene groups to create hydrogel networks that rapidly crosslink via thiol-ene click chemistry with tailored mechanics. Mechanical properties were controlled by modulating the amount of matrix metalloproteinase (MMP)-degradable peptide crosslinker to produce hydrogels with increasing elastic moduli of 1.1 ± 0.002, 3.0 ± 0.002, and 10.6 ± 0.006 kPa mimicking a relevant range of developing and mature muscle stiffnesses. Functional muscle recovery was assessed following implantation of the HA hydrogels by in situ photopolymerization into rat latissimus dorsi (LD) VML defects at 12 and 24 weeks post-injury. After 12 weeks, muscles treated with medium stiffness (3.0 kPa) hydrogels produced maximum isometric forces most similar to contralateral healthy LD muscles. This trend persisted at 24 weeks post-injury, suggestive of sustained functional recovery. Histological analysis revealed a significantly larger zone of regeneration with more de novo muscle fibers following implantation of medium stiffness hydrogels in VML-injured muscles compared to other experimental groups. Lower (low and medium) stiffness hydrogels also appeared to attenuate the chronic inflammatory response characteristic of VML injuries, displaying similar levels of macrophage infiltration and polarization to healthy muscle. Together these findings illustrate the importance of hydrogel mechanical properties in supporting functional repair of VML injuries.

Molecular insights of hyaluronic acid-hydroxychloroquine conjugate as a promising drug in targeting SARS-CoV-2 viral proteins

In-silico anti-viral activity of Hydroxychloroquine (HCQ) and its Hyaluronic Acid-derivative (HA-HCQ) towards different SARS-CoV-2 protein molecular targets were studied. Four different SARS-CoV-2 proteins molecular target i.e., three different main proteases and one helicase were chosen for In-silico anti-viral analysis. The HA-HCQ conjugates exhibited superior binding affinity and interactions with all the screened SAR-CoV-2 molecular target proteins with the exception of a few targets. The study also revealed that the HA-HCQ conjugate has multiple advantages of efficient drug delivery to its CD44 variant isoform receptors of the lower respiratory tract, highest interactive binding affinity with SARS-CoV-2 protein target. Moreover, the HA-HCQ drug conjugate possesses added advantages of good biodegradability, biocompatibility, non-toxicity and non-immunogenicity. The prominent binding ability of HA-HCQ conjugate towards Mpro (PDB ID 5R82) and Helicase (PDB ID 6ZSL) target protein as compared with HCQ alone was proven through MD simulation analysis. In conclusion, our study suggested that further in-vitro and in-vivo examination of HA-HCQ drug conjugate will be useful to establish a promising early stage antiviral drug for the novel treatment of COVID-19.

Celecoxib repurposing in cancer therapy: molecular mechanisms and nanomedicine-based delivery technologies

While cancer remains a significant global health problem, advances in cancer biology, deep understanding of its underlaying mechanism and identification of specific molecular targets allowed the development of new therapeutic options. Drug repurposing poses several advantages as reduced cost and better safety compared with new compounds development. COX-2 inhibitors are one of the most promising drug classes for repurposing in cancer therapy. In this review, we provide an overview of the detailed mechanism and rationale of COX-2 inhibitors as anticancer agents and we highlight the most promising research efforts on nanotechnological approaches to enhance COX-2 inhibitors delivery with special focus on celecoxib as the most widely studied agent for chemoprevention or combined with chemotherapeutic and herbal drugs for combating various cancers.

Cardiovascular Effects Mediated by HMMR and CD44

Cardiovascular disease (CVD) is the leading cause of death worldwide. The most dangerous life-threatening symptoms of CVD are myocardial infarction and stroke. The causes of CVD are not entirely clear, and new therapeutic targets are still being sought. One of the factors involved in CVD development among vascular damage and oxidative stress is chronic inflammation. It is known that hyaluronic acid plays an important role in inflammation and is regulated by numerous stimuli, including proinflammatory cytokines. The main receptors for hyaluronic acid are CD44 and RHAMM. These receptors are membrane proteins that differ in structure, but it seems that they can perform similar or synergistic functions in many diseases. Both RHAMM and CD44 are involved in cell migration and wound healing. However, their close association with CVD is not fully understood. In this review, we describe the role of both receptors in CVD.

Therapeutic Efficacy of Cryopreserved, Allogeneic Extracellular Vesicles for Treatment of Acute Myocardial Infarction

Extracellular vesicles (EV) that are derived from endothelial progenitor cells (EPC) have been determined to be a novel therapy for acute myocardial infarction, with a promise for immediate "off-the-shelf" delivery. Early experience suggests delivery of EVs from allogeneic sources is safe. Yet, clinical translation of this therapy requires assurances of both EV stability following cryopreservation and absence of an adverse immunologic response to EVs from allogeneic donors. Thus, more bioactivity studies on allogeneic EVs after cold storage are necessary to establish quality standards for its widespread clinical use. Thus, in this study, we aimed to demonstrate the safety and efficacy in delivering cryopreserved EVs in allogeneic recipients as a therapy for acute myocardial infarction.In this present study, we have analyzed the cardioprotective effects of allogeneic EPC-derived EVs after storage at -80°C for 2 months, using a shear-thinning gel (STG) as an in vivo delivery vehicle. EV size, proteome, and nucleic acid cargo were observed to remain steady through extended cryopreservation via nanoparticle tracking analysis, mass spectrometry, and nanodrop analysis, respectively. Fresh and previously frozen EVs in STG were delivered intramyocardially in a rat model of myocardial infarction (MI), with both showing improvements in contractility, angiogenesis, and scar thickness in comparison to phosphate-buffered saline (PBS) and STG controls at 4 weeks post-MI. Pathologic analyses and flow cytometry revealed minimal inflammatory and immune upregulation upon exposure of tissue to EVs pooled from allogeneic donor cells.Allogeneic EPC-EVs have been known to elicit minimal immune activity and retain therapeutic efficacy after at least 2 months of cryopreservation in a post-MI model.

Semisynthetic Hyaluronic Acid-Based Hydrogel Promotes Recovery of the Injured Tibialis Anterior Skeletal Muscle Form and Function

Volumetric muscle loss (VML) injuries are characterized by a degree of tissue loss that exceeds the endogenous regenerative capacity of muscle, resulting in permanent structural and functional deficits. Such injuries are a consequence of trauma, as well as a host of congenital and acquired diseases and disorders. Despite significant preclinical research with diverse biomaterials, as well as early clinical studies with implantation of decellularized extracellular matrices, there are still significant barriers to more complete restoration of muscle form and function following repair of VML injuries. In fact, identification of novel biomaterials with more advantageous regenerative profiles is a critical limitation to the development of improved therapeutics. As a first step in this direction, we evaluated a novel semisynthetic hyaluronic acid-based (HyA) hydrogel that embodies material features more favorable for robust muscle regeneration. This HyA-based hydrogel is composed of an acrylate-modified HyA (AcHyA) macromer, an AcHyA macromer conjugated with the bsp-RGD(15) peptide sequence to enhance cell adhesion, a high-molecular-weight heparin to sequester growth factors, and a matrix metalloproteinase-cleavable cross-linker to allow for cell-dependent remodeling. In a well-established, clinically relevant rat tibialis anterior VML injury model, we report observations of robust functional recovery, accompanied by volume reconstitution, muscle regeneration, and native-like vascularization following implantation of the HyA-based hydrogel at the site of injury. These findings have important implications for the development and clinical application of the improved biomaterials that will be required for stable and complete functional recovery from diverse VML injuries.

Co-localization and crosstalk between CD44 and RHAMM depend on hyaluronan presentation

CD44 and the receptor for hyaluronic acid-mediated motility (RHAMM) are the main hyaluronan (HA) receptors. They are commonly overexpressed in different cancers activating signaling pathways related to tumor progression, metastasis and chemoresistance. Besides their involvement in signal transduction via interaction with HA, currently, there is a little information about the possible crosstalk between CD44 and RHAMM and the role of HA in this process. In the present work, we used immunocytochemistry combined with Förster resonance energy transfer (FRET) microscopy and co-immunoprecipitation to elucidate the involvement of HA in CD44 and RHAMM expression, co-localization and crosstalk. We studied breast cancer cells lines with different degrees of invasiveness and expression of these receptors in the absence of exogenous HA and compared the data with the results obtained for cultures supplemented with either soluble HA or seeded on substrates with end-on immobilized HA. Our results demonstrated that cells response depends on the HA presentation: CD44/RHAMM complexation was upregulated in all cell lines upon interaction with immobilized HA, but not with its soluble form. Moreover, the results showed that the expression of both CD44 and RHAMM is regulated via interactions with HA indicating cell-specific feedback loop(s) in the signaling cascade.