Injectable tissue prosthesis for instantaneous closed-loop rehabilitation.

To construct tissue-like prosthetic materials, soft electroactive hydrogels are the best candidate owing to their physiological mechanical modulus, low electrical resistance and bidirectional stimulating and recording capability of electrophysiological signals from biological tissues1,2. Nevertheless, until now, bioelectronic devices for such prostheses have been patch type, which cannot be applied onto rough, narrow or deep tissue surfaces3-5. Here we present an injectable tissue prosthesis with instantaneous bidirectional electrical conduction in the neuromuscular system. The soft and injectable prosthesis is composed of a biocompatible hydrogel with unique phenylborate-mediated multiple crosslinking, such as irreversible yet freely rearrangeable biphenyl bonds and reversible coordinate bonds with conductive gold nanoparticles formed in situ by cross-coupling. Closed-loop robot-assisted rehabilitation by injecting this prosthetic material is successfully demonstrated in the early stage of severe muscle injury in rats, and accelerated tissue repair is achieved in the later stage.

Self-assembling paclitaxel-mediated stimulation of tumor-associated macrophages for postoperative treatment of glioblastoma.

The unique cancer-associated immunosuppression in brain, combined with a paucity of infiltrating T cells, contributes to the low response rate and poor treatment outcomes of T cell-based immunotherapy for patients diagnosed with glioblastoma multiforme (GBM). Here, we report on a self-assembling paclitaxel (PTX) filament (PF) hydrogel that stimulates macrophage-mediated immune response for local treatment of recurrent glioblastoma. Our results suggest that aqueous PF solutions containing aCD47 can be directly deposited into the tumor resection cavity, enabling seamless hydrogel filling of the cavity and long-term release of both therapeutics. The PTX PFs elicit an immune-stimulating tumor microenvironment (TME) and thus sensitizes tumor to the aCD47-mediated blockade of the antiphagocytic "don't eat me" signal, which subsequently promotes tumor cell phagocytosis by macrophages and also triggers an antitumor T cell response. As adjuvant therapy after surgery, this aCD47/PF supramolecular hydrogel effectively suppresses primary brain tumor recurrence and prolongs overall survivals with minimal off-target side effects.

Relieving Macrophage Dysfunction by Inhibiting SREBP2 Activity: A Hypoxic Mesenchymal Stem Cells-Derived Exosomes Loaded Multifunctional Hydrogel for Accelerated Diabetic Wound Healing.

Macrophage dysfunction is one of the primary factors leading to the delayed healing of diabetic wounds. Hypoxic bone marrow mesenchymal stem cells-derived exosomes (hyBMSC-Exos) have been shown to play an active role in regulating cellular function through the carried microRNAs. However, the administration of hyBMSC-Exos alone in diabetic wounds usually brings little effect, because the exosomes are inherently unstable and have a short retention time at the wounds. In this study, a multifunctional hydrogel based on gallic acid (GA) conjugated chitosan (Chi-GA) and partially oxidized hyaluronic acid (OHA) is prepared for sustained release of hyBMSC-Exos. The hydrogel not only exhibits needs-satisfying physicochemical properties, but also displays outstanding biological performances such as low hemolysis rate, strong antibacterial capacity, great antioxidant ability, and excellent biocompatibility. It has the ability to boost the stability of hyBMSC-Exos, leading to a continuous and gradual release of the exosomes at wound locations, ultimately enhancing the exosomes' uptake efficiency by target cells. Most importantly, hyBMSC-Exos loaded hydrogel shows an excellent ability to promote diabetic wound healing by regulating macrophage polarization toward M2 phenotype. This may be because exosomal miR-4645-5p and antioxidant property of the hydrogel synergistically inhibit SREBP2 activity in macrophages. This study presents a productive approach for managing diabetic wounds.

In situ chemoimmunotherapy hydrogel elicits immunogenic cell death and evokes efficient antitumor immune response.

BACKGROUND: Chemoimmunotherapy has shown promising advantages of eliciting immunogenic cell death and activating anti-tumor immune responses. However, the systemic toxicity of chemotherapy and tumor immunosuppressive microenvironment limit the clinical application. METHODS: Here, an injectable sodium alginate hydrogel (ALG) loaded with nanoparticle albumin-bound-paclitaxel (Nab-PTX) and an immunostimulating agent R837 was developed for local administration. Two murine hepatocellular carcinoma and breast cancer models were established. The tumor-bearing mice received the peritumoral injection of R837/Nab-PTX/ALG once a week for two weeks. The antitumor efficacy, the immune response, and the tumor microenvironment were investigated. RESULTS: This chemoimmunotherapy hydrogel with sustained-release character was proven to have significant effects on killing tumor cells and inhibiting tumor growth. Peritumoral injection of our hydrogel caused little harm to normal organs and triggered a potent antitumor immune response against both hepatocellular carcinoma and breast cancer. In the tumor microenvironment, enhanced immunogenic cell death induced by the combination of Nab-PTX and R837 resulted in 3.30-fold infiltration of effector memory T cells and upregulation of 20 biological processes related to immune responses. CONCLUSIONS: Our strategy provides a novel insight into the combination of chemotherapy and immunotherapy and has the potential for clinical translation.

Effective Treatment of Helicobacter pylori Infection Using Supramolecular Antimicrobial Peptide Hydrogels.

Helicobacter pylori can cause various gastric conditions including stomach cancer in an acidic environment. Although early H. pylori infections can be treated by antibiotics, prolonged antibiotic administrations may lead to the development of antimicrobial resistance, compromising the effectiveness of the treatments. Antimicrobial peptides (AMPs) have been reported to possess unique advantages against antimicrobial-resistant bacteria due to their rapid physical membrane disruptions and anti-inflammation/immunoregulation properties. Herein, we have developed an AMP hydrogel, which can be orally administered for the treatment of H. pylori infection. The hydrogel has potent antimicrobial activity against H. pylori, achieving bacterial eradication within minutes of action. Compared with the AMP solution, the hydrogel formulation significantly reduced the cytotoxicity and enhanced proteolytic stability. In vivo experiments suggested that the hydrogel formed at pH 4 had superior therapeutic effects to those at pH 7 and 10 hydrogels, attributed to its rapid release and bactericidal action within the acidic stomach environment. Compared to conventional antibiotic treatments, the AMP hydrogel had the advantages of fast bacterial killing in the gastric juice and obviated proton pump inhibitors during the treatment. Although both the AMP hydrogel and antibiotics suppressed the expression of pro-inflammatory cytokines, the former uniquely promoted inflammation resolution. These results indicate that the AMP hydrogels with effectiveness and biosafety may be potential candidates for the clinical treatment of H. pylori infections.

Injectable Alginate Complex Hydrogel Loaded with Dual-Drug Nanovectors Offers Effective Photochemotherapy against Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC), accounting for approximately 20% of breast cancer cases, is a particular subtype that lacks tumor-specific targets and is difficult to treat due to its high aggressiveness and poor prognosis. Chemotherapy remains the major systemic treatment for TNBC. However, its applicability and efficacy in the clinic are usually concerning due to a lack of targeting, adverse side effects, and occurrence of multidrug resistance, suggesting that the development of effective therapeutics is still highly demanded nowadays. In this study, an injectable alginate complex hydrogel loaded with indocyanine green (ICG)-entrapped perfluorocarbon nanoemulsions (IPNEs) and camptothecin (CPT)-doped chitosan nanoparticles (CCNPs), named IPECCNAHG, was developed for photochemotherapy against TNBC. IPNEs with perfluorocarbon can induce hyperthermia and generate more singlet oxygen than an equal dose of free ICG upon near-infrared (NIR) irradiation to achieve photothermal and photodynamic therapy. CCNPs with positive charge may facilitate cellular internalization and provide sustained release of CPT to carry out chemotherapy. Both nanovectors can stabilize agents in the same hydrogel system without interactions. IPECCNAHG integrating IPNEs and CCNPs enables stage-wise combinational therapeutics that may overcome the issues described above. With 60 s of NIR irradiation, IPECCNAHG significantly inhibited the growth of MDA-MB-231 tumors in the mice without systemic toxicity within the 21 day treatment. We speculate that such anticancer efficacy was accomplished by phototherapy followed by chemotherapy, where cancer cells were first destroyed by IPNE-derived hyperthermia and singlet oxygen, followed by sustained damage with CPT after internalization of CCNPs; a two-stage tumoricidal process. Taken together, the developed IPECCNAHG is anticipated to be a feasible tool for TNBC treatment in the clinic.

Hydrogel dressings for diabetic foot ulcer: A systematic review and meta-analysis.

AIM: To investigate the differences in utility between conventional dressings and hydrogel dressings for the treatment of diabetic foot ulcer (DFU). METHODS: The PubMed, Embase, Cochrane Library, CNKI, VIP and Wanfang databases were systematically searched up to 21 January 2023. Fixed/random-effect models were used to calculate the odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (CIs) for the effect size analysis, with heterogeneity determined by I2 statistics. Subgroup analyses of different classes of hydrogel were also conducted. RESULTS: A total of 15 randomized controlled trials with 872 patients were eligible for the present analysis. Compared with conventional dressings, hydrogel dressings significantly improved the healing rate (OR 4.09, 95% CI 2.83 to 5.91), shortened the healing time (MD -11.38, 95% CI -13.11 to -9.66), enhanced granulation formation (MD -3.60, 95% CI -4.21 to -3.00) and epithelial formation (MD -2.82, 95% CI -3.19 to -2.46), and reduced the incidence of bacterial infection (OR 0.10, 95% CI 0.05 to 0.18). CONCLUSION: The meta-analysis showed that hydrogel dressings are more effective in treating DFU compared with conventional dressings.

Injectable hydrogel-based combination therapy for myocardial infarction: a systematic review and Meta-analysis of preclinical trials.

INTRODUCTION: This study evaluates the effectiveness of a combined regimen involving injectable hydrogels for the treatment of experimental myocardial infarction. PATIENT CONCERNS: Myocardial infarction is an acute illness that negatively affects quality of life and increases mortality rates. Experimental models of myocardial infarction can aid in disease research by allowing for the development of therapies that effectively manage disease progression and promote tissue repair. DIAGNOSIS: Experimental animal models of myocardial infarction were established using the ligation method on the anterior descending branch of the left coronary artery (LAD). INTERVENTIONS: The efficacy of intracardiac injection of hydrogels, combined with cells, drugs, cytokines, extracellular vesicles, or nucleic acid therapies, was evaluated to assess the functional and morphological improvements in the post-infarction heart achieved through the combined hydrogel regimen. OUTCOMES: A literature review was conducted using PubMed, Web of Science, Scopus, and Cochrane databases. A total of 83 papers, including studies on 1332 experimental animals (rats, mice, rabbits, sheep, and pigs), were included in the meta-analysis based on the inclusion and exclusion criteria. The overall effect size observed in the group receiving combined hydrogel therapy, compared to the group receiving hydrogel treatment alone, resulted in an ejection fraction (EF) improvement of 8.87% [95% confidence interval (CI): 7.53, 10.21] and a fractional shortening (FS) improvement of 6.31% [95% CI: 5.94, 6.67] in rat models, while in mice models, the improvements were 16.45% [95% CI: 11.29, 21.61] for EF and 5.68% [95% CI: 5.15, 6.22] for FS. The most significant improvements in EF (rats: MD = 9.63% [95% CI: 4.02, 15.23]; mice: MD = 23.93% [95% CI: 17.52, 30.84]) and FS (rats: MD = 8.55% [95% CI: 2.54, 14.56]; mice: MD = 5.68% [95% CI: 5.15, 6.22]) were observed when extracellular vesicle therapy was used. Although there have been significant results in large animal experiments, the number of studies conducted in this area is limited. CONCLUSION: The present study demonstrates that combining hydrogel with other therapies effectively improves heart function and morphology. Further preclinical research using large animal models is necessary for additional study and validation.

Enhanced immunomodulation and periodontal regeneration efficacy of subgingivally delivered progranulin-loaded hydrogel as an adjunct to non-surgical treatment for Class II furcation involvement in dogs.

AIM: To evaluate the effect of subgingival delivery of progranulin (PGRN)/gelatin methacryloyl (GelMA) complex as an adjunct to scaling and root planing (SRP) on an experimental periodontitis dog model with Class II furcation involvement (FI). MATERIALS AND METHODS: A Class II FI model was established, and the defects were divided into four treatment groups: (a) no treatment (control); (b) SRP; (c) SRP + GelMA; (d) SRP + PGRN/GelMA. Eight weeks after treatment, periodontal parameters were recorded, gingival crevicular fluid and gingival tissue were collected for ELISA and RT-qPCR, respectively, and mandibular tissue blocks were collected for micro computed tomography (micro-CT) scanning and hematoxylin and eosin (H&E) staining. RESULTS: The SRP + PGRN/GelMA group showed significant improvement in all periodontal parameters compared with those in the other groups. The expression of markers related to M1 macrophage and Th17 cell significantly decreased, and the expression of markers related to M2 macrophage and Treg cell significantly increased in the SRP + PGRN/GelMA group compared with those in the other groups. The volume, quality and area of new bone and the length of new cementum in the root furcation defects of the PGRN/GelMA group were significantly increased compared to those in the other groups. CONCLUSIONS: Subgingival delivery of the PGRN/GelMA complex could be a promising non-surgical adjunctive therapy for anti-inflammation, immunomodulation and periodontal regeneration.

Engineered Living Bacteriophage-Enabled Self-Adjuvanting Hydrogel for Remodeling Tumor Microenvironment and Cancer Therapy.

Due to the complexity and heterogeneity in the tumor microenvironment, the efficacy of breast cancer treatment has been significantly impeded. Here, we established a living system using an engineered M13 bacteriophage through chemical cross-linking and biomineralization to remodel the tumor microenvironment. Chemically cross-linking of the engineered bacteriophage gel (M13 Gel) could in situ synthesize photothermal palladium nanoparticles (PdNPs) on the pVIII capsid protein to obtain M13@Pd Gel. In addition, NLG919 was further loaded into a gel to form (M13@Pd/NLG gel) for down-regulating the expression of tryptophan metabolic enzyme indoleamine 2,3-dioxygenase 1 (IDO1). Both in vitro and in vivo studies showed that the M13 bacteriophage served not only as a cargo-loaded device but also as a self-immune adjuvant, which induced the immunogenic death of tumor cells effectively and down-regulated IDO1 expression. Such a bioactive gel system constructed by natural living materials could reverse immunosuppression and significantly improve the anti-breast cancer response.

Two-Pronged Microbe Delivery of Nitric Oxide and Oxygen for Diabetic Wound Healing.

Chronic inflammation and hypoxia in the microenvironment of diabetic foot ulcers (DFUs) can result in sustained vascular impairment, hindering tissue regeneration. While both nitric oxide and oxygen have been shown to promote wound healing in DFUs through anti-inflammatory and neovascularization, there is currently no available therapy that delivers both. We present a novel hydrogel consisting of Weissella and Chlorella, which alternates between nitric oxide and oxygen production to reduce chronic inflammation and hypoxia. Further experiments indicate that the hydrogel accelerates wound closure, re-epithelialization, and angiogenesis in diabetic mice and improves the survival of skin grafts. This dual-gas therapy holds promise as a potential treatment option for the management of diabetic wounds.

In vitro evaluation of bactericidal effects of fluorescent light energy on Staphylococcus pseudintermedius and S. aureus.

BACKGROUND: Staphylococcus pseudintermedius and S. aureus are bacterial species of importance in veterinary medicine. The increasing incidence of antibiotic resistance necessitates the implementation of novel treatment modalities. Fluorescent light energy (FLE) is used as an adjunctive and primary treatment for canine pyoderma. However, no in vitro studies exist investigating its bactericidal effects against S. pseudintermedius or S. aureus. OBJECTIVES: To determine the bactericidal effects of FLE on S. pseudintermedius and S. aureus isolates. MATERIALS AND METHODS: Two meticillin-susceptible S. pseudintermedius (MSSP) isolates, three meticillin-resistant S. pseudintermedius (MRSP) isolates and one meticillin-resistant S. aureus (MRSA) isolate were studied. A commercially available blue light-emitting diode (bLED) lamp and photoconverting hydrogel FLE system was used. All bacteria were exposed to five conditions following inoculation: (i) no treatment (control); (ii) blue light (bLED) once; (iii) bLED twice consecutively; (iv) FLE (bLED and photoconverting hydrogel) once; and (v) FLE (bLED and photoconverting hydrogel) twice consecutively. Each individual exposure was 2 min long. RESULTS: No statistically significant differences (p < 0.05) were found for any treatment group when each bacterial isolate was evaluated individually, MSSP isolates were grouped, MRSP isolates were grouped, when all S. pseudintermedius isolates were combined, or when all isolates of both Staphylococcus species were combined. CONCLUSIONS AND CLINICAL RELEVANCE: While clinical success is reported when using FLE to treat Staphylococcus infections in animals, no in vitro antibacterial efficacy was identified for S. pseudintermedius or S. aureus under experimental conditions. The clinical success observed with FLE may be the result of a more complex in vivo response.

Intradermal Injection of Hybrid Complexes of High- and Low-Molecular-Weight Hyaluronan: Where Do We Stand and Where Are We Headed in Regenerative Medicine?

Hyaluronic acid (HA) is a remarkably multifaceted biomacromolecule, playing a role in regulating myriad biological processes such as wound healing, tissue regeneration, anti-inflammation, and immunomodulation. Crosslinked high- and low-molecular-weight hyaluronic acid hydrogels achieve higher molar concentrations, display slower degradation, and allow optimal tissue product diffusion, while harnessing the synergistic contribution of different-molecular-weight hyaluronans. A recent innovation in the world of hyaluronic acid synthesis is represented by NAHYCO® Hybrid Technology, a thermal process leading to hybrid cooperative hyaluronic acid complexes (HCC). This review summarizes the current literature on the in vitro studies and in vivo applications of HCC, from facial and body rejuvenation to future perspectives in skin wound healing, dermatology, and genitourinary pathologies.

Hydrogel-Based Skin Regeneration.

The skin is subject to damage from the surrounding environment. The repair of skin wounds can be very challenging due to several factors such as severe injuries, concomitant infections, or comorbidities such as diabetes. Different drugs and wound dressings have been used to treat skin wounds. Tissue engineering, a novel therapeutic approach, revolutionized the treatment and regeneration of challenging tissue damage. This field includes the use of synthetic and natural biomaterials that support the growth of tissues or organs outside the body. Accordingly, the demand for polymer-based therapeutic strategies for skin tissue defects is significantly increasing. Among the various 3D scaffolds used in tissue engineering, hydrogel scaffolds have gained special significance due to their unique properties such as natural mimicry of the extracellular matrix (ECM), moisture retention, porosity, biocompatibility, biodegradability, and biocompatibility properties. First, this article delineates the process of wound healing and conventional methods of treating wounds. It then presents an examination of the structure and manufacturing methods of hydrogels, followed by an analysis of their crucial characteristics in healing skin wounds and the most recent advancements in using hydrogel dressings for this purpose. Finally, it discusses the potential future advancements in hydrogel materials within the realm of wound healing.

Emerging Multiscale Biofabrication Approaches for Bacteriotherapy.

Bacteriotherapy is emerging as a strategic and effective approach to treat infections by providing putatively harmless bacteria (i.e., probiotics) as antagonists to pathogens. Proper delivery of probiotics or their metabolites (i.e., post-biotics) can facilitate their availing of biomaterial encapsulation via innovative manufacturing technologies. This review paper aims to provide the most recent biomaterial-assisted strategies proposed to treat infections or dysbiosis using bacteriotherapy. We revised the encapsulation processes across multiscale biomaterial approaches, which could be ideal for targeting different tissues and suit diverse therapeutic opportunities. Hydrogels, and specifically polysaccharides, are the focus of this review, as they have been reported to better sustain the vitality of the live cells incorporated. Specifically, the approaches used for fabricating hydrogel-based devices with increasing dimensionality (D)-namely, 0D (i.e., particles), 1D (i.e., fibers), 2D (i.e., fiber meshes), and 3D (i.e., scaffolds)-endowed with probiotics, were detailed by describing their advantages and challenges, along with a future overlook in the field. Electrospinning, electrospray, and 3D bioprinting were investigated as new biofabrication methods for probiotic encapsulation within multidimensional matrices. Finally, examples of biomaterial-based systems for cell and possibly post-biotic release were reported.

Histological evaluation of the regenerative potential of a novel photocrosslinkable gelatin-treated dentin matrix hydrogel in direct pulp capping: an animal study.

BACKGROUND: To assess histologically the success of the pulp capping approach performed in traumatically exposed dogs' teeth using a novel injectable gelatin-treated dentin matrix light cured hydrogel (LCG-TDM) compared with LCG, MTA and TheraCal LC. METHODS: Sixty-four dogs' teeth were divided into two groups (each including 32 teeth) based on the post-treatment evaluation period: group I: 2 weeks and group II: 8 weeks. Each group was further subdivided according to the pulp capping material into four subgroups (n = 8), with subgroup A (light-cured gelatin hydrogel) as the control subgroup, subgroup B (LCG-TDM), subgroup C (TheraCal LC), and subgroup D (MTA). Pulps were mechanically exposed in the middle of the cavity floor and capped with different materials. An assessment of periapical response was performed preoperatively and at 8 weeks. After 2 and 8-week intervals, the dogs were sacrificed, and the teeth were stained with hematoxylin-eosin and graded by using a histologic scoring system. Statistical analysis was performed using the chi-square and Kruskal-Wallis tests (p = 0.05). RESULTS: All subgroups showed mild inflammation with normal pulp tissue at 2 weeks with no significant differences between subgroups (p ≤ 0.05), except for the TheraCal LC subgroup, which exhibited moderate inflammation (62.5%). Absence of a complete calcified bridge was reported in all subgroups at 2 weeks, while at 8 weeks, the majority of samples in the LCG-TDM and MTA-Angelus subgroups showed complete dentin bridge formation and absence of inflammatory pulp response with no significant differences between them (p ≤ 0.05). However, the formed dentin in the LCG-TDM group was significantly thicker, with layers of ordered odontoblasts identified to create a homogeneous tubular structure and numerous dentinal tubule lines suggesting a favourable trend towards dentin regeneration. TheraCal LC samples revealed a reasonably thick dentin bridge with moderate inflammation (50%) and LCG showed heavily fibrous tissue infiltrates with areas of degenerated pulp with no signs of hard tissue formation. CONCLUSIONS: LCG-TDM, as an extracellular matrix-based material, has the potential to regenerate dentin and preserve pulp vitality, making it a viable natural alternative to silicate-based cements for healing in vivo dentin defects in direct pulp-capping procedures.

Characterization and application of in situ curcumin/ZNP hydrogels for periodontitis treatment.

BACKGROUND: Periodontitis is a chronic inflammatory disease that occurs in tooth-supporting tissues. Controlling inflammation and alleviating periodontal tissue destruction are key factors in periodontal therapy. This study aimed to develop an in situ curcumin/zinc oxide (Cur/ZNP) hydrogel and investigate its characteristics and effectiveness in the treatment of periodontitis. METHODS: Antibacterial activity and cytotoxicity assays were performed in vitro. To evaluate the effect of the in situ Cur/ZNP hydrogel on periodontitis in vivo, an experimental periodontitis model was established in Sprague‒Dawley rats via silk ligature and inoculation of the maxillary first molar with Porphyromonas gingivalis. After one month of in situ treatment with the hydrogel, we examined the transcriptional responses of the gingiva to the Cur/ZNP hydrogel treatment and detected the alveolar bone level as well as the expression of osteocalcin (OCN) and osteoprotegerin (OPG) in the periodontal tissues of the rats. RESULTS: Cur/ZNPs had synergistic inhibitory effects on P. gingivalis and good biocompatibility. RNA sequencing of the gingiva showed that immune effector process-related genes were significantly induced by experimental periodontitis. Carcinoembryonic antigen-related cell adhesion molecule 1 (Ceacam1), which is involved in the negative regulation of bone resorption, was differentially regulated by the Cur/ZNP hydrogel but not by the Cur hydrogel or ZNP hydrogel. The Cur/ZNP hydrogel also had a stronger protective effect on alveolar bone resorption than both the Cur hydrogel and the ZNP hydrogel. CONCLUSION: The Cur/ZNP hydrogel effectively inhibited periodontal pathogenic bacteria and alleviated alveolar bone destruction while exhibiting favorable biocompatibility.

Recent advances on 3D-bioprinted gelatin methacrylate hydrogels for tissue engineering in wound healing: A review of current applications and future prospects.

Advancements in 3D bioprinting, particularly the use of gelatin methacrylate (GelMA) hydrogels, are ushering in a transformative era in regenerative medicine and tissue engineering. This review highlights the pivotal role of GelMA hydrogels in wound healing and skin regeneration. Its biocompatibility, tunable mechanical properties and support for cellular proliferation make it a promising candidate for bioactive dressings and scaffolds. Challenges remain in optimizing GelMA hydrogels for clinical use, including scalability of 3D bioprinting techniques, durability under physiological conditions and the development of advanced bioinks. The review covers GelMA's applications from enhancing wound dressings, promoting angiogenesis and facilitating tissue regeneration to addressing microbial infections and diabetic wound healing. Preclinical studies underscore GelMA's potential in tissue healing and the need for further research for real-world applications. The future of GelMA hydrogels lies in overcoming these challenges through multidisciplinary collaboration, advancing manufacturing techniques and embracing personalized medicine paradigms.

Fabrication of Cu/ZnO-loaded chitosan hydrogel for an effective wound dressing material to advanced wound care and healing efficiency after caesarean section surgery.

Wound infections and delayed complications after caesarean section surgical procedure to mothers would have a prevalence of discomfort, stress and dissatisfaction in the postpartum period. In this report, one-pot synthesis is used for the preparation of chitosan (CS)-based copper nanoparticles (nCu), which was used for the preparation of zinc oxide (ZnO) hydrogel as wound dressing materials after surgery. The antibacterial activity of (CS-nCu/ZnO) developed hydrogels was studied zone of inhibition, against gram-positive and gram-negative bacteria. The antibacterial activity of the CS-nCu/ZnO hydrogel demonstrated that nanoformulated hydrogel materials have provided excellent bactericidal action against clinically approved bacterial pathogens. The biocompatibility and in vitro wound healing potential of the developed wound closure materials were studied by MTT assay and wound scratch assay methods, respectively. The MTT assay and cell migration assay results demonstrated that CS-nCu/ZnO hydrogel material induces cell compatibility and effective cell proliferation ability. These findings suggest that the CS-nCu/ZnO hydrogel outperforms CS-ZnO in terms of wound healing and could be used as a wound closure material in caesarean section wound treatment.

Polyvinyl alcohol hydrogel implant for the treatment of hallux rigidus is associated with a high complication rate and moderate failure rate at short-term follow-up: a systematic review.

PURPOSE: Moderate-to-severe hallux rigidus is a debilitating pathology that is optimally treated with surgical intervention. Arthrodesis produces reliable clinical outcomes but is limited by restriction in 1st metatarsophalangeal joint range of motion. The advent of polyvinyl alcohol hydrogel (PVA) implants have produced early promise based on initial trials, but more recent studies have called into question the efficacy of this procedure. The purpose of this systematic review was to evaluate the clinical and radiological outcomes following the use of PVA for hallux rigidus. METHODS: The MEDLINE, EMBASE and Cochrane library databases were systematically reviewed using the preferred reporting items for systematic reviews and meta-analyses guidelines. 18 studies were included. RESULTS: In total, 1349 patients (1367 feet) underwent PVA at a weighted mean follow-up of 24.1 ± 11.1 months. There were 168 patients (169 feet) included in the cheilectomy cohort and 322 patients (322 feet) included in the arthrodesis cohort. All 3 cohorts produced comparable improvements in subjective clinical outcomes. Postoperative imaging findings in the PVA cohort included joint space narrowing, peri-implant fluid, peri-implant edema and erosion of the proximal phalanx. The complication rate in the PVA cohort, cheilectomy cohort and arthrodesis cohort was 27.9%, 11.8% and 24.1%, respectively. The failure rates in the PVA cohort, cheilectomy cohort and arthrodesis cohort was 14.8%, 0.3% and 9.0%, respectively. CONCLUSION: This systematic review demonstrated that PVA produced a high complication rate (27.9%) together with concerning postoperative imaging findings at short-term follow-up. In addition, a moderate failure rate (14.8%) and secondary surgical procedure rate (9.5%) was noted for the PVA cohort. The findings of this review calls into question the efficacy and safety of PVA for the treatment of hallux rigidus. LEVEL OF EVIDENCE: IV.