Exosomes derived from adipose stem cells in combination with hyaluronic acid promote diabetic wound healing.

Diabetic wound is one of the main challenges in dermatology. Although stem cell-based treatment has therapeutic benefits in wound repair, the clinical application is still limited. Herein we investigated whether adipose stem cells -derived exosomes (Exo) loaded on hyaluronic acid (HA) could promote healing in diabetic rats. Sixty diabetic rats were randomly planned into the control group, Exo group, HA group, and HA+Exo group. On days 7, 14, and 21, five rats from each group were sampled for stereological, molecular, and tensiometrical assessments. Our results indicated that the wound closure rate, the total volumes of new epidermis and dermis, the numerical densities of fibroblasts, the length density blood vessels, collagen density as well as tensiometrical parameters of the healed wounds were significantly higher in the treated groups than in the control group, and these changes were more obvious in the HA+Exo ones. Furthermore, the expression of TGF-ß and VEGF genes were meaningfully upregulated in all treated groups compared to the control group and were greater in the HA+Exo group. This is while expression of TNF-α and IL-1ß, as well as numerical densities of neutrophils decreased more considerably in the HA+Exo group in comparison to the other groups. Generally, it was found that using both HA injection and exosomes has more effect on diabetic wound healing.

Effects of Radiation-Induced Skin Injury on Hyaluronan Degradation and Its Underlying Mechanisms.

Radiation-induced skin injury (RISI) is a frequent and severe complication with a complex pathogenesis that often occurs during radiation therapy, nuclear incidents, and nuclear war, for which there is no effective treatment. Hyaluronan (HA) plays an overwhelming role in the skin, and it has been shown that UVB irradiation induces increased HA expression. Nevertheless, to the best of our knowledge, there has been no study regarding the biological correlation between RISI and HA degradation and its underlying mechanisms. Therefore, in our study, we investigated low-molecular-weight HA content using an enzyme-linked immunosorbent assay and changes in the expression of HA-related metabolic enzymes using real-time quantitative polymerase chain reaction and a Western blotting assay. The oxidative stress level of the RISI model was assessed using sodium dismutase, malondialdehyde, and reactive oxygen species assays. We demonstrated that low-molecular-weight HA content was significantly upregulated in skin tissues during the late phase of irradiation exposure in the RISI model and that HA-related metabolic enzymes, oxidative stress levels, the MEK5/ERK5 pathway, and inflammatory factors were consistent with changes in low-molecular-weight HA content. These findings prove that HA degradation is biologically relevant to RISI development and that the HA degradation mechanisms are related to HA-related metabolic enzymes, oxidative stress, and inflammatory factors. The MEK5/ERK5 pathway represents a potential mechanism of HA degradation. In conclusion, we aimed to investigate changes in HA content and preliminarily investigate the HA degradation mechanism in a RISI model under γ-ray irradiation, to consider HA as a new target for RISI and provide ideas for novel drug development.

Effect of intra-articular injection of a hyaluronic acid-alendronate conjugate on post-traumatic osteoarthritis induced by destabilization of the medial meniscus in rats.

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by pain and cartilage damage. Intra-articular (i.a) viscosupplementation with hyaluronic acid (HA) is frequently used for the management of OA. Preclinical studies have reported that bisphosphonates (BPs) may have a therapeutic potential to slow down or reverse the progression of OA. Among these, alendronate (ALN) has demonstrated chondroprotective effects in both in vitro and vivo experiments. This study evaluated the effects of a novel alendronate-hyaluronic acid (ALN-HA) conjugate on an OA in vivo model induced by medial meniscus destabilization (DMM). DMM surgery was performed on the knees of Sprague Dawley rats that received, after four weeks, one intra-articular (i.a.) injection of: (1) ALN-HA; (2) HA; (3) sodium chloride (NaCl). Sham-operated rats were used as control. Allodynia was assessed by Von Frey test. Joint degeneration was evaluated eight weeks after treatment by micro-computed tomography (micro-CT), histology, and immunohistochemistry. Collagen cross-linked C-telopeptides (CTX-I and CTX-II) serum levels were determined by ELISA. Paw withdrawal threshold increased in ALN-HA group when compared to rats treated with NaCl or HA. Micro-CT did not show differences between ALN-HA, HA and NaCl groups. ALN-HA injection produced significant improvements in articular cartilage degeneration showing an OARSI score lower than those of HA and NaCl, and reduced matrix metalloproteinase (MMP)-13, MMP-3, interleukin-6, vascular endothelial growth factor and Caspase-3 expression. CTX-I was reduced after ALN-HA treatment when compared to NaCl. Our results indicate that i.a. use of ALN after conjugation with HA limits OA development and progression in the rat DMM model, and may lead to the development of novel therapeutic strategies in OA management.

Hyaluronic Acid Conjugated with 17ß-Estradiol Effectively Alleviates Estropause-Induced Cognitive Deficits in Rats.

Women are at a higher risk of cognitive impairments and Alzheimer's disease (AD), particularly after the menopause, when the estrous cycle becomes irregular and diminishes. Numerous studies have shown that estrogen deficiency, especially estradiol (E2) deficiency, plays a key role in this phenomenon. Recently, a novel polymeric drug, hyaluronic acid-17ß-estradiol conjugate (HA-E2), has been introduced for the delivery of E2 to brain tissues. Studies have indicated that HA-E2 crosses the blood-brain barrier (BBB) and facilitates a prolonged E2 release profile while lowering the risk of estrogen-supplement-related side effects. In this study, we used ovariohysterectomy (OHE) rats, a postmenopausal cognitive deficit model, to explore the effect of a 2-week HA-E2 treatment (210 ng/kg body weight, twice a week) on the cholinergic septo-hippocampal innervation system, synaptic transmission in hippocampal pyramidal neurons and cognitive improvements. Our study revealed an 11% rise in choline acetyltransferase (ChAT) expression in both the medial septal nucleus (MS nucleus) and the hippocampus, along with a 14-18% increase in dendritic spine density in hippocampal pyramidal neurons, following HA-E2 treatment in OHE rats. These enhancements prompted the recovery of cognitive functions such as spatial learning and memory. These findings suggest that HA-E2 may prevent and improve estrogen-deficiency-induced cognitive impairment and AD.

Investigation into the effect of epidermal growth factor and hyaluronic acid on fracture healing in a rat femoral fracture model.

OBJECTIVE: This study aimed to investigate the role of an exogenous Epidermal Growth Factor and a hyaluronic acid-based scaffold on fracture healing in a rat femoral fracture model Methods: Forty-eight male Wistar-Albino rats, each weighing a mean 392 grams (range= 350-450 grams) and aged 8.2 months (6-9 months), were used for this experimental study. All surgical procedures were performed on the left femur by a single surgeon. An open femoral fracture was created in all rats. The animals were randomly divided into one of the four groups: Control (12), EGF (12), HA (12) and Combined (12). In the 4th and sixth weeks, samples were processed and analyzed using biomechanical and histological methods. RESULTS: Fracture healing was significantly improved in the Combined group compared to the control one, EGF and HA groups in all parameters at both experimental time points. At the fourth and sixth weeks after surgery, fracture healing in the EGF and HA groups was significantly increased at histological evaluation compared to controls. In addition, compared with EGF, HA and Control groups, a significant difference in callus tissue was detected in the Combined group at 4 and 6-week time points in biomechanical features. CONCLUSION: This study has shown that combining local EGF and HA scaffold accelerates bone healing and strengthens the bony callus histologically and biomechanically. Using EGF-HA combined scaffolds may represent a possible future strategy in trauma surgery. LEVEL OF EVIDENCE: N/A.

Quality-by-Design Approach for Investigating the Efficacy of Tacrolimus and Hyaluronic Acid-Loaded Ethosomal Gel in Dermal Management of Psoriasis: In Vitro, Ex Vivo, and In Vivo Evaluation.

Psoriasis is an auto-immune condition with high keratinocyte hyperproliferation due to lower p53 and p22 levels. Tacrolimus, an immune suppressor, is considered one of the most effective drugs in suppressing psoriasis. Systematic administration of tacrolimus often leads to challenging side effects, namely increased infection risk, renal toxicity, neurological symptoms such as tremors and headaches, gastrointestinal disturbances, hypertension, skin-related problems, etc. To address this, a nanocarrier-based formulation of tacrolimus along with inclusion of hyaluronic acid was developed. The optimization and formulation of ethosomes via the ethanol injection technique were done based on the Box-Behnken experimental design. The results revealed hyaluronic acid-based tacrolimus ethosomes (HA-TAC-ETH) had nanometric vesicle size (315.7 ± 2.2 nm), polydispersity index (PDI) (0.472 ± 0.07), and high entrapment efficiency (88.3 ± 2.52%). The findings of drug release and skin permeation showed sustained drug release with increased dermal flux and enhancement ratio. The effectiveness of HA-TAC-ETH was confirmed in an imiquimod (5%)-prompted psoriasis model. The skin irritation score and Psoriasis Area and Severity Index (PASI) score indicated that HA-TAC-ETH gel has validated a decline in the entire factors (erythema, edema, and thickness) in the imiquimod-induced psoriasis model in contrast with TAC-ETH gel and TAC ointment. The fabricated HA-TAC-ETH opt gel proved to be safe and effective in in vivo studies and could be employed to treat psoriasis further.

Production and Partial Characterization of Bioactive Compounds from Underutilized Marine Bioresources for a Cosmetic Formulation: Cytotoxicity and Bioactivity Evaluation.

Hydrolyzed collagen, glycogen, and hyaluronic acid, obtained through the biotechnological valorization of underutilized marine bioresources, fulfill cosmetic industry requirements for sustainable products produced under circular economy principles. Hydrolyzed collagen was obtained by hydrolyzing blue shark collagen with papain and ultrafiltration. Glycogen was isolated from industrial mussel cooking wastewaters through ultrafiltration, precipitation, and selective polysaccharide separation. Hyaluronic acid was produced by fermentation, purification, and depolymerization. The main objective was to test the feasibility of including these three biomolecules in a cosmetic formulation as bioactive compounds. For this, the in vitro irritant potential of the three ingredients and also that of the cosmetic formulation was assayed according to the Reconstituted Human Epithelium Test method OECD 439. Moreover, an in vitro assessment of the effect of hydrolyzed collagen and hyaluronic acid combinations on mRNA expression and collagen type I synthesis was evaluated in adult human fibroblasts. This study establishes, for the first time, the potential use of particular hydrolyzed collagen and hyaluronic acid combinations as stimulators of collagen I synthesis in fibroblast cultures. Besides, it provide safety information regarding potential use of those biomolecules in the formulation of a cosmetic preparation positively concluding that both, ingredients and cosmetic preparation, resulted not irritant for skin following an international validated reference method.

Components and physical properties of hydrogels modulate inflammatory response and cartilage repair.

Collagen and hyaluronic acid are commonly applied in cartilage tissue engineering, yet there has been limited investigation into their inflammatory response, a crucial factor in articular cartilage repair. This study aimed to evaluate the impact of components and physical properties of hydrogels on inflammatory response and cartilage repair. Three kinds of hydrogels with comparable storage moduli at low frequencies were designed and fabricated, namely, methacrylic anhydride-modified hyaluronic acid hydrogel (HAMA), methacrylic anhydride-modified type I collagen hydrogel (CMA) and unmodified type I collagen hydrogel (Col). HAMA hydrogel was unfavorable for adhesion and spreading of BMSCs. Furthermore, HAMA hydrogel stimulated rapid migration and pro-inflammatory M1 polarization of macrophages, leading to persistent and intense inflammation, which was unfavorable for cartilage repair. CMA and Col hydrogels possessed the same component and facilitated the adhesion, spreading and proliferation of BMSCs. Compared with CMA hydrogel, Col hydrogel induced rapid migration and moderate M1 polarization of macrophages at the early stage of injury, which was mainly influenced by its fast dissolution rate, small pore size fiber network structure and rapid stress relaxation. In addition, the phenotype of macrophages timely transformed into anti-inflammatory M2 due to the properties of the collagen component, which shortened the duration of inflammation and enhanced cartilage repair. The results indicated that moderate macrophage activation adjusted by hydrogel components and physical properties was critical in modulating inflammation and cartilage regeneration.

Protecting Tear-Film Stability under Adverse Environmental Conditions Using a Mucomimetic with a Non-Newtonian Viscosity Agent.

Background and Objectives: Tamarind-seed polysaccharide (TSP) and hyaluronic acid (HA) have mucoadhesive properties that improve drug absorption and delay in drug elimination from the ocular surface. We aimed to evaluate TSP/HA-containing formulation for its efficiency in dry-eye symptoms induced by adverse environments and the interaction between mucomimic polymer and tear-film parameters. Materials and Methods: The participants were exposed to 5% relative humidity (RH) in a Controlled Environment Chamber (CEC) under constant room temperature (21 °C). Tear-film parameters were assessed at 40% RH and 5% RH. Rohto Dry Eye Relief drops were used in the two treatment modalities, protection (drops instilled before exposure to the dry environment) and relief (drops instilled after exposure to the dry environment). The HIRCAL grid, Servomed EP3 Evaporimeter, and Keeler's TearScope-Plus were used to screen for non-invasive tear break-up time (NITBUT), tear evaporation rate, and lipid-layer thickness (LLT) using protection and relief treatment methodology. Results: LLT was found to be significantly thinner at 5% RH compared with at 40% RH (p = 0.007). The median LLT dropped from 50-70 nm (grade 3) at 40% RH to 10-50 nm (grade 2) at 5% RH. TSP/HA eye drops significantly augment LLT in both treatment modalities, protection (p = 0.01) and relief (p = 0.004) at 5% RH. The mean evaporation rate doubled from 40.93 at 40% RH to 82.42 g/m2/h after exposure to 5% RH. In protection mode, the TSP/HA allowed the average evaporation rate to be much lower than when no TSP/HA was used at 5% RH (p < 0.008). No alteration in evaporation rate was recorded when the TSP/HA drop was used after exposure (relief). The mean NITBUT was reduced from 13 s in normal conditions to 6 s in the dry environment. Instillation of TSP/HA eye drops resulted in significant improvement (p = 0.006) in tear stability, where the NITBUT increased to 8 s in both protection (before exposure) and relief (after exposure) (p = 0.001). Although improved, these values were still significantly lower than NITBUT observed at 40% RH. Conclusions: Significant protection of tear-film parameters was recorded post instillation of TSP/HA eye drop under a desiccating environment. Both treatment methods (protection and relief) were shown to be effective. The presence of TSP/HA enhances the effectiveness of teardrops in protecting the tear-film parameters when exposed to adverse environments.

Low, medium, and high molecular weight hyaluronic acid effects on human dental pulp stem cells in vitro.

Hyaluronic acid (HA), an extracellular biopolymer found throughout the human body, holds promise as a biocompatible and biodegradable scaffold material. High molecular weight (HMW) HA degrades, generating low molecular weight (LMW) fragments with distinct properties. These fragments can influence the behaviour of cells, including human dental pulp stem cells (hDPSCs) incorporated into HA-containing hydrogels or scaffolds. Therefore, a comprehensive examination of the impact of a range of HA molecular weights on hDPSCs is essential before designing HA-based scaffolds for these cells. hDPSC lines were cultured with LMW HA (800 Da, 1600 Da, 15 kDa), medium molecular weight HA (237 kDa), or HMW HA (1500 kDa) over six passages. The various molecular weights had negligible effects on hDPSCs viability, morphology, adhesion, or relative telomere length. Furthermore, the expression of key surface stemness markers (CD29, CD44, CD73, CD90) remained unaltered. HA did not induce osteogenic, chondrogenic, or adipogenic differentiation. Moreover, the potential for chondrogenic and osteogenic differentiation was not adversely affected by LMW or HMW HA. Various molecular weights of HA seem safe, biocompatible and therefore suitable components for hDPSCs-containing scaffolds. These findings affirm that the hDPCSs will not be negatively affected by HA fragments resulting from scaffold degradation.

An injectable and light curable hyaluronic acid composite gel with anti-biofilm, anti-inflammatory and pro-healing characteristics for accelerating infected wound healing.

Bacterial biofilm formation and drug resistance are common issues associated with wound healing. Antimicrobial peptides (AMPs) are a new class of antimicrobial agents with the potential to solve these global health issues. New injectable adhesive antibacterial hydrogels have excellent prospects of becoming the next innovative wound-healing dressings. In this study, the hyaluronic acid was connected to the antibacterial peptide Plantaricin 149 (Pln149), obtaining HAD@AMP. HAD@AMP performed well in efficient antimicrobial activity, good histocompatibility, low drug resistance, low bacterial biofilm formation, and fast wound healing process which are essential for rapid healing of infected wound. During the hydrogel degradation process, Pln149 was released to inhibit bacterial communication and reduce bacterial biofilm formation. Meanwhile, HAD@AMP could up-regulate anti-inflammatory and pro-angiogenic factors, and down-regulate inflammatory factors to promote the healing of infected wounds, which provide a new idea for skin healing strategies.

Enhanced intra-articular therapy for rheumatoid arthritis using click-crosslinked hyaluronic acid hydrogels loaded with toll-like receptor antagonizing peptides.

Rheumatoid arthritis (RA) is a chronic inflammatory disorder that results in the deterioration of joint cartilage and bone. Toll-like receptor 4 (TLR4) has been pinpointed as a key factor in RA-related inflammation. While Toll-like receptor antagonizing peptide 2 (TAP2) holds potential as an anti-inflammatory agent, its in vivo degradation rate hinders its efficacy. We engineered depots of TAP2 encapsulated in click-crosslinked hyaluronic acid (TAP2+Cx-HA) for intra-articular administration, aiming to enhance the effectiveness of TAP2 as an anti-inflammatory agent within the joint cavity. Our data demonstrated that FI-TAP2+Cx-HA achieves a longer retention time in the joint cavity compared to FI-TAP2 alone. Mechanistically, we found that TAP2 interacts with TLR4 on the cell membranes of inflammatory cells, thereby inhibiting the nuclear translocation of NF-κB and maintaining it in an inactive cytoplasmic state. In a rat model of RA, the TAP2+Cx-HA formulation effectively downregulated the inflammatory cytokines TNF-α and IL-6, while upregulating the anti-inflammatory cytokine IL-10 and the therapeutic protein 14-3-3ζ. This led to a more rapid restoration of cartilage thickness, increased deposition of glycosaminoglycans, and new bone tissue formation in the regenerated cartilage, in comparison to a single TAP2 treatment after a six-week period. Our results suggest that TAP2+Cx-HA could serve as a potent intra-articular treatment for RA, offering both symptomatic relief and promoting cartilage regeneration. This innovative delivery system holds significant promise for improving the management of RA and other inflammatory joint conditions. STATEMENT OF SIGNIFICANCE: In this study, we developed a therapy by creating toll-like receptor 4 (TLR4)-antagonizing peptide (TAP2)-loaded click-crosslinked hyaluronic acid (TAP2+Cx-HA) depots for direct intra-articular injection. Our study demonstrates that FI-TAP2+Cx-HA exhibits a more than threefold longer lifetime in the joint cavity compared to FI-TAP2 alone. Furthermore, we found that TAP2 binds to TLR4 and masks the nuclear localization signals of NF-κB, leading to its sequestration in an inactive state in the cytoplasm. In a rat model of RA, TAP2+Cx-HA effectively suppresses inflammatory molecules, specifically TNF-α and IL-6, while upregulating the anti-inflammatory cytokine IL-10 and the therapeutic protein 14-3-3ζ. This resulted in faster regeneration of cartilage thickness, increased glycosaminoglycan deposits in the regenerated cartilage, and a twofold increase in new bone tissue formation compared to a single TAP2 treatment.

Decellularized allogeneic cartilage paste with human costal cartilage and crosslinked hyaluronic acid-carboxymethyl cellulose carrier augments microfracture for improved articular cartilage repair.

Articular cartilage lacks natural healing abilities and necessitates surgical treatments for injuries. While microfracture (MF) is a primary surgical approach, it often results in the formation of unstable fibrocartilage. Delivering hyaline cartilage directly to defects poses challenges due to the limited availability of autologous cartilage and difficulties associated with allogeneic cartilage delivery. We developed a decellularized allogeneic cartilage paste (DACP) using human costal cartilage mixed with a crosslinked hyaluronic acid (HA)-carboxymethyl cellulose (CMC) carrier. The decellularized allogeneic cartilage preserved the extracellular matrix and the nanostructure of native hyaline cartilage. The crosslinked HA-CMC carrier provided shape retention and moldability. In vitro studies confirmed that DACP did not cause cytotoxicity and promoted migration, proliferation, and chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells. After 6 months of implantation in rabbit knee osteochondral defects, DACP combined with MF outperformed MF alone, demonstrating improved gait performance, defect filling, morphology, extracellular matrix deposition, and biomechanical properties similar to native cartilage. Thus, DACP offers a safe and effective method for articular cartilage repair, representing a promising augmentation to MF. STATEMENT OF SIGNIFICANCE: Directly delivering hyaline cartilage to repair articular cartilage defects is an ideal treatment. However, current allogeneic cartilage products face delivery challenges. In this study, we developed a decellularized allogeneic cartilage paste (DACP) by mixing human costal cartilage with crosslinked hyaluronic acid (HA)-carboxymethyl cellulose (CMC). DACP preserves extracellular matrix components and nanostructures similar to native cartilage, with HA-CMC ensuring shape retention and moldability. Our study demonstrates improved cartilage repair by combining DACP with microfracture, compared to microfracture alone, in rabbit knee defects over 6 months. This is the first report showing better articular cartilage repair using decellularized allogeneic cartilage with microfracture, without the need for exogenous cells or bioactive substances.

In situ photo-crosslinkable hyaluronic acid-based hydrogel embedded with GHK peptide nanofibers for bioactive wound healing.

A versatile hydrogel was developed for enhancing bioactive wound healing by introducing the amphiphilic GHK peptide (GHK-C16) into a photo-crosslinkable tyramine-modified hyaluronic acid (HA-Ty). GHK-C16 self-assembled into GHK nanofibers (GHK NF) in HA-Ty solution, which underwent in situ gelation after the wound area was filled with precursor solution. Blue light irradiation (460-490 nm), with riboflavin phosphate as a photoinitiator, was used to trigger crosslinking, which enhanced the stability of the highly degradable hyaluronic acid and enabled sustained release of the nanostructured GHK derivatives. The hydrogels provided a microenvironment that promoted the proliferation of dermal fibroblasts and the activation of cytokines, leading to reduced inflammation and increased collagen expression during wound healing. The complexation of Cu2+ into GHK nanofibers resulted in superior wound healing capabilities compared with non-lipidated GHK peptide with a comparable level of growth factor (EGF). Additionally, nanostructured Cu-GHK improved angiogenesis through vascular endothelial growth factor (VEGF) activation, which exerted a synergistic therapeutic effect. Furthermore, in vivo wound healing experiments revealed that the Cu-GHK NF/HA-Ty hydrogel accelerated wound healing through densely packed remodeled collagen in the dermis and promoting the growth of denser fibroblasts. HA-Ty hydrogels incorporating GHK NF also possessed improved mechanical properties and a faster wound healing rate, making them suitable for advanced bioactive wound healing applications. STATEMENT OF SIGNIFICANCE: By combining photo-crosslinkable tyramine-modified hyaluronic acid with self-assembled Cu-GHK-C16 peptide nanofibers (Cu-GHK NF), the Cu-GHK NF/HA-Ty hydrogel offers remarkable advantages over conventional non-structured Cu-GHK for wound healing. It enhances cell proliferation, migration, and collagen remodeling-critical factors in tissue regeneration. The incorporation of GHK nanofibers complexed with copper ions imparts potent anti-inflammatory effects, promoting cytokine activation and angiogenesis during wound healing. The Cu-GHK NF/hydrogel's unique properties, including in situ photo-crosslinking, ensure high customization and potency in tissue regeneration, providing a cost-effective alternative to growth factors. In vivo experiments further validate its efficacy, demonstrating significant wound closure, collagen remodeling, and increased fibroblast density. Overall, the Cu-GHK NF/HA-Ty hydrogel represents an advanced therapeutic option for wound healing applications.

Guanosine-driven hyaluronic acid-based supramolecular hydrogels with peroxidase-like activity for chronic diabetic wound treatment.

Guanosine is often used to construct supramolecular hydrogels due to its self-assembly properties, however, the high temperature and strong alkaline construction methods greatly limit its application in biomedical fields. In this work, a guanosine-driven hyaluronic acid-based supramolecular hydrogel was developed under mild condition by employing phenylboronic acid-functionalized hyaluronic acid (HA-PBA) backbone and guanosine molecules. Guanosines self-assembled into G-quartet planes under potassium ion conditions, and formed boronic ester bonds with HA-PBA, which induced rapid formation of dynamically cross-linked hydrogels. Hemin was then binding to the G-quartet plane via π-π interactions in the hydrogels, which exhibited peroxidase activity and were highly effective in killing bacteria by generating hydroxyl radicals in the presence of H2O2. Furthermore, glucose oxidase (GOx) was incorporated into the hydrogels and the HP/G@hemin@GOx hydrogels showed good antibacterial properties, modulation of wound glucose and ROS level, and good therapeutic efficacy for diabetic chronic wounds. Overall, the self-assembly of guanosine has been shown for the first time to be a feasible method for constructing natural polymer-based supramolecular hydrogels. This guanosine-driven HA-based supramolecular hydrogel can act as a potential wound dressing for chronic diabetic wound treatment. STATEMENT OF SIGNIFICANCE: Chronic wound repair remains an unsolved clinical challenge. Herein, we propose to utilize phenylboronic acid-modified hyaluronic acid and guanosine to construct supramolecular gels with peroxidase activity for chronic wound treatment. The self-assembly behavior of guanosine drives the natural macromolecular backbone to form the hydrogel, and the proposed method simplifies the gelation conditions and improves its biosafety. The G-quartets formed by the self-assembly of guanosine can act as the loading site for hemin. G-quartet/hemin complex imported peroxidase activity to the hydrogels, endowing them with the ability to kill bacteria and regulate ROS levels of cells in the wound site. This guanosine-driven supramolecular hydrogel significantly increased the rate of wound healing in diabetic mice, promising a new strategy for chronic wound treatment.

Boron Nitride's Morphological Role in the Design of Injectable Hyaluronic Acid Based Hybrid Artificial Synovial Fluid.

The treatment process of osteoarthritis (OA) is challenging as it affects not only cartilage but also subchondral bone, ligament attachment capsules, synovium, and surrounding muscle tissue. Therefore, the search for preventive treatment or methods to slow the onset of the condition. Hexagonal boron nitride (hBN) has a graphite-like lamellar structure and is thought to facilitate cartilage movement for biomedical applications, just like in bearing systems. Hyaluronic acid (HA) is one of the natural polymers that can be used to transport boron nitride and maintain its presence in joints for a long time. In this study, hybrid hydrogels were formulated by using boron nitride nanoparticles and nanosheets. The rheological properties of the hydrogels were evaluated according to the structural differences of hBN. Characterizations have shown that hybrid hydrogels can be produced in injectable form, and the rheological properties are strongly related to the structural properties of the added particle. It has been determined that hBN added to the hydrogel structure reduces the dynamic viscosity of the zero-shear point and the deformation rate of the hydrogel and also changes the viscoelastic properties of the hydrogel depending on boron nitride's structural differences. The suggested mechanism is the hybrid hydrogel that exhibits lower viscosity as the layers detach from each other or disperses the agglomerates under applied shear stress. hBN, which has been proposed as a new strategy for joint injections, is thought to be a promising candidate for the treatment of OA due to its lamellar structures.

Efficacy of hyaluronic acid gel and photobiomodulation therapy on wound healing after surgical gingivectomy: a randomized controlled clinical trial.

BACKGROUND: Surgical gingivectomy can be considered the gold standard treatment for gingival enlargement. The healing of wound site after gingivectomy occurs slowly by secondary intention. To accelerate the wound healing process, several studies have been conducted evaluating the effect of various treatment modalities. Photobiomodulation therapy (PBMT) was proposed to provide minimally invasive and painless treatment as well as to decrease discomfort of the patient following the surgical process. Another factor that is expected to improve the healing after surgery is topical application of chemotherapeutic agents such as Hyaluronic acid (HA). This study aims to assess the effect of topically applied HA gel after PBMT on the healing of wound site after surgical gingivectomy. METHODS: This randomized controlled clinical trial included twenty-six surgical gingivectomy wound sites, equally divided into two groups, Group-I (test group): the surgical sites after gingivectomy were irradiated with a diode laser (980 nm, 0.2 W) then covered by 2% HA gel loaded in a special custom-made soft transparent tissue guard appliance for each patient. Group II (control group): the surgical sites were irradiated with a diode laser (980 nm, 0.2 W) only. Wound healing was assessed subjectively by Landry healing index on the 3rd, 7th, 14th and 21st days after surgery, and pain perception was assessed by the patients using visual analog scale (VAS) throughout the 21 days of the follow up period. Comparisons between the two study groups were performed using Mann-Whitney U test, while comparisons between different time points were performed using Friedman test. Significance was inferred at p value < 0.05. RESULTS: By the end of the follow-up period, surgical sites of the test group showed excellent healing compared to the control group. There were no significant differences in VAS scores between both groups (p > 0.05). CONCLUSIONS: Application of 2% HA gel as an adjunctive to PBMT was found to have significant clinical effects and higher power of repair among test group when compared to that achieved by PBMT alone in control group. TRIAL REGISTRATION: This study was retrospectively registered on ClinicalTrials.gov and first posted on 28th of March 2023 with an identifier number: NCT05787912.

Mucosal absorption of antibody drugs enhanced by cell-penetrating peptides anchored to a platform of polysaccharides.

Our previous studies demonstrated that L-octaarginine grafted onto hyaluronic acid via a tetraglycine spacer significantly enhanced intranasal absorption of protein drugs with a molecular weight (Mw) of 22 kDa or less. The present study focused on its potential as an absorption enhancer for antibody drugs with a larger Mw and the enhancement mechanism. When ranibizumab (48 kDa) alone was intranasally administered in mice, its absolute bioavailability was 0.67% on average. The mean bioavailability elevated to 6.2% under coadministration with tetraglycine-L-octaarginine-linked hyaluronic acid. A similar result was observed under substitution of ranibizumab with certolizumab pegol (91 kDa), although bioavailability itself decreased with the Mw increase, irrespective of coadministration with the hyaluronic acid derivative. Rat experiments also revealed that coadministration with the polysaccharide derivative resulted in significant enhancement of intranasal absorption of trastuzumab (148 kDa). In vitro studies using gene-knocked down cells indicated that syndecan-4-induced macropinocytosis played a crucial role on acceleration of antibody uptake into epithelial cells on the nasal mucosa, irrespective of their Mw. It appeared that neither clathrin heavy chain nor caveolin-1 involved in cellular uptake of antibodies. Tetraglycine-L-octaarginine-linked hyaluronic acid was concluded to be a promising delivery tool that possessed universal absorption-enhancing abilities independent to Mw of biologics.

A self-gelling hydrogel based on thiolated hyaluronic acid for three-dimensional culture of ovine preantral follicles.

Three-dimensional (3D) ovarian follicle culture offers a promising option for fertility preservation in patients who cannot receive ovarian tissue transplantation. Our research evaluated the potential of a hydrogel composed of thiolated hyaluronic acid (HA-SH) for ovine preantral follicle development compared to routinely used alginate hydrogel (ALG). Synthesized via a carbodiimide reaction, HA-SH facilitated a self-crosslinking hydrogel through disulfide bond formation. Ovine preantral follicles (200-300 µm) retrieved through mechanical and enzymatic methods were encapsulated individually in either ALG or HA-SH hydrogels. Although both hydrogels adequately supported follicle survival, 3D integrity, and antrum formation over a 17-day in vitro culture, follicle growth was significantly higher within the HA-SH hydrogel. Gene expression analysis underscored that some folliculogenesis-related genes (ZP3, BMP7, and GJA1) and a steroidogenic gene (CYP19A1) demonstrated higher expression levels in HA-SH encapsulated follicles versus ALG. Collectively, our findings advocate for HA-SH hydrogel as a potent biomaterial for in vitro follicle cultures, attributing its efficacy to facile gelation, bio-responsiveness, and superior support for follicle growth.

Immune-microenvironment modulatory polyurethane-hyaluronic acid hybrid hydrogel scaffolds for diabetic wound treatment.

The healing of wounds in diabetic patients is a huge challenge issue in clinical medicine due to the disordered immune. Recruiting endogenous cells to play a role in the early stage and timely reducing inflammation to promote healing in the middle or late of injuring are both prerequisites for effective treatment. Here, inspired by natural extracellular matrix, three-dimensional porous polyurethane-hyaluronic acid hybrid hydrogel scaffolds (PUHA) were prepared to repair diabetic wound through activate cell immunity by moderate foreign body reaction, provide cell adhesion growth extracellular matrix of hyaluronic acid (HA) and exhibit anti-inflammatory effect of polyurethane (PU). The interaction between PU and HA alters the compact PU hydrogel into macroporous PUHA hydrogel scaffolds with super-swelling, elastic mechanical properties, and controllable degradation, which are suitable for endogenous cells infiltration, growth and immune activation. Additionally, incorporating with RGD, PUHA hydrogel scaffolds with bioactive physicochemical features can evidently reduce the inflammation and modulate the polarization of macrophage apparently both in vitro and in vivo, mainly through downregulation of cytokine-cytokine receptor interaction genes, leading to reprogramming immune-microenvironment and rapid diabetic wound healing. This method of gathering cells initially and intervening immune-microenvironment in time provides an expected way to design biomaterials for chronic wound healing.