Combined Silver Sulfadiazine Nanosuspension with Thermosensitive Hydrogel: An Effective Antibacterial Treatment for Wound Healing in an Animal Model

Novel β-Hairpin Antimicrobial Peptide Containing the β-Turn Sequence of -NG- and the Tryptophan Zippers Facilitate Self-Assembly into Nanofibers, Exhibiting Excellent Antimicrobial Performance

Antimicrobial peptides (AMPs) have emerged as promising agents to combat the antibiotic resistance crisis due to their rapid bactericidal activity and low propensity for drug resistance. However, AMPs face challenges in terms of balancing enhanced antimicrobial efficacy with increased toxicity during modification processes. In this study, de novo d-type β-hairpin AMPs are designed. The conformational transformation of self-assembling peptide W-4 in the environment of the bacterial membrane and the erythrocyte membrane affected its antibacterial activity and hemolytic activity and finally showed a high antibacterial effect and low toxicity. Furthermore, W-4 displays remarkable stability, minimal occurrence of drug resistance, and synergistic effects when combined with antibiotics. The in vivo studies confirm its high safety and potent wound-healing properties at the sites infected by bacteria. This study substantiates that nanostructured AMPs possess enhanced biocompatibility. These advances reveal the superiority of self-assembled AMPs and contribute to the development of nanoantibacterial materials.

Fabrication of Bilayer Nanofibrous-Hydrogel Scaffold from Bacterial Cellulose, PVA, and Gelatin as Advanced Dressing for Wound Healing and Soft Tissue Engineering

Tissue engineering is currently one of the fastest-growing areas of engineering, requiring the fabrication of advanced and multifunctional materials that can be used as scaffolds or dressings for tissue regeneration. In this work, we report a bilayer material prepared by electrospinning a hybrid material of poly(vinyl alcohol) (PVA) and bacterial cellulose (BC NFs) (top layer) over a highly interconnected porous 3D gelatin-PVA hydrogel obtained by a freeze-drying process (bottom layer). The techniques were combined to produce an advanced material with synergistic effects on the physical and biological properties of the two materials. The bilayer material was characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and a water contact measurement system (WCMS). Studies on swelling, degradability, porosity, drug release, cellular and antibacterial activities were performed using standardized procedures and assays. FTIR confirmed cross-linking of both the top and bottom layers, and SEM showed porous structure for the bottom layer, random deposition of NFs on the surface, and aligned NFs in the cross section. The water contact angle (WCA) showed a hydrophilic surface for the bilayer material. Swelling analysis showed high swelling, and degradation analysis showed good stability. The bilayer material released Ag-sulfadiazine in a sustained and controlled manner and showed good antibacterial activities against severe disease-causing gram + ive and -ive (Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa) bacterial strains. In vitro biological studies were performed on fibroblasts (3T3) and human embryonic kidneys (HEK-293), which showed desirable cell viability, proliferation, and adhesion to the bilayer. Thus, the synergistic effect of NFs and the hydrogel resulted in a potential wound dressing material for wound healing and soft tissue engineering.

Antimicrobial Hydrogels: Potential Materials for Medical Application

Microbial infections based on drug-resistant pathogenic organisms following surgery or trauma and uncontrolled bleeding are the main causes of increased mortality from trauma worldwide. The prevalence of drug-resistant pathogens has led to a significant increase in medical costs and poses a great threat to the normal life of people. This is an important issue in the field of biomedicine, and the emergence of new antimicrobial materials hydrogels holds great promise for solving this problem. Hydrogel is an important material with good biocompatibility, water absorption, oxygen permeability, adhesion, degradation, self-healing, corrosion resistance, and controlled release of drugs as well as structural diversity. Bacteria-disturbing hydrogels have important applications in the direction of surgical treatment, wound dressing, medical device coating, and tissue engineering. This paper reviews the classification of antimicrobial hydrogels, the current status of research, and the potential of antimicrobial hydrogels for one application in biomedicine, and analyzes the current research of hydrogels in biomedical applications from five aspects: metal-loaded hydrogels, drug-loaded hydrogels, carbon-material-loaded hydrogels, hydrogels with fixed antimicrobial activity and biological antimicrobial hydrogels, and provides an outlook on the high antimicrobial activity, biodegradability, biocompatibility, injectability, clinical applicability and future development prospects of hydrogels in this field.

Combined Therapy of Experimental Autoimmune Uveitis by a Dual-Drug Nanocomposite Formulation with Berberine and Dexamethasone

Purpose

Autoimmune uveitis is a kind of sight-threatening ocular and systemic disorders. Recent treatments on autoimmune uveitis still remain many limitations due to extreme complexity and undetermined pathogenesis. In this study, a novel dual-drug nanocomposite formulation is developed to treat experimental autoimmune uveitis by a combined and sustained therapy method.

Methods

The dual-drug nanocomposite formulation is constructed by integrating berberine (BBR)-loaded mesoporous silica nanoparticles (MSNs) into dexamethasone (DEX)-loaded thermogel (BBR@MSN-DEX@Gel). The BBR@MSN-DEX@Gel is characterized by transmission electron microscopy, dynamic light scattering, Fourier transform infrared spectrometer and rheometer. The in vitro drug release profile, cytotoxicity and anti-inflammation effectiveness of BBR@MSN-DEX@Gel on lipopolysaccharide-stimulated human conjunctival epithelial cells are investigated. After the in vivo drug release profile and biosafety of the dual-drug nanocomposite formulation are confirmed, its treatment effectiveness is fully assessed based on the induced experimental autoimmune uveitis (EAU) Lewis rat's model.

Results

The dual-drug nanocomposite formulation has good injectability and thermosensitivity, suitable for administration by an intravitreal injection. The BBR@MSN-DEX@Gel has been found to sustainably release both drugs for up to 4 weeks. The carrier materials have minimal in vitro cytotoxicity and high in vivo biosafety. BBR@MSN-DEX@Gel presents obviously anti-inflammatory effectiveness in vitro. After administration of BBR@MSN-DEX@Gel into Lewis rat's eye with EAU by an intravitreal injection, the nanocomposite formulation significantly suppresses inflammatory reaction of autoimmune uveitis via a dual-drug combined and sustained therapy method, compared with the equivalent dose of single-component formulations.

Conclusion

BBR@MSN-DEX@Gel serves as a promising dual-drug nanocomposite formulation for future treatment of autoimmune uveitis.

Advanced Drug Delivery System for Management of Chronic Diabetes Wound Healing

The diabetic wound is excessively vulnerable to infection because the diabetic wound suggests delayed and incomplete healing techniques. Presently, wounds and ulcers related to diabetes have additionally increased the medical burden. A diabetic wound can impair mobility, lead to amputations, or even death. In recent times, advanced drug delivery systems have emerged as promising approaches for enhancing the efficacy of wound healing treatments in diabetic patients. This review aims to provide an overview of the current advancements in drug delivery systems in managing chronic diabetic wound healing. This review begins by discussing the pathophysiological features of diabetic wounds, including impaired angiogenesis, elevated reactive oxygen species, and compromised immune response. These factors contribute to delayed wound healing and increased susceptibility to infection. The importance of early intervention and effective wound management strategies is emphasized. Various types of advanced drug delivery systems are then explored, including nanoparticles, hydrogels, transferosomes, liposomes, niosomes, dendrimers, and nanosuspension with incorporated bioactive agents and biological macromolecules are also utilized for chronic diabetes wound management. These systems offer advantages such as sustained release of therapeutic agents, improved targeting and penetration, and enhanced wound closure. Additionally, the review highlights the potential of novel approaches such as antibiotics, minerals, vitamins, growth factors gene therapy, and stem cell-based therapy in diabetic wound healing. The outcome of advanced drug delivery systems holds immense potential in managing chronic diabetic wound healing. They offer innovative approaches for delivering therapeutic agents, improving wound closure, and addressing the specific pathophysiological characteristics of diabetic wounds.