Drug-Loaded Polymeric Composite Skin Graft for Infection-Free Wound Healing: Fabrication, Characterization, Cell Proliferation, Migration, and Antimicrobial Activity

Antibiotics against Pseudomonas aeruginosa on Human Skin Cell Lines: Determination of the Highest Non-Cytotoxic Concentrations with Antibiofilm Capacity for Wound Healing Strategies

Pseudomonas aeruginosa is one of the most common microorganisms causing infections of severe skin wounds. Antibiotic or antiseptic treatments are crucial to prevent and curb these infections. Antiseptics have been reported to be cytotoxic to skin cells and few studies evaluate the impact of commonly used antibiotics. This study evaluates how clinical antibiotics affect skin cells' viability, proliferation, migration, and cytokine secretion and defines the highest non-cytotoxic concentrations that maintain antibacterial activity. Cell proliferation, viability, and migration were evaluated on cell monolayers. Cytokines related to the wound healing process were determined. The minimum inhibitory concentrations and the impact on bacterial biofilm were assessed. Results showed that 0.02 mg/mL ciprofloxacin and 1 mg/mL meropenem are the highest non-cytotoxic concentrations for fibroblasts and keratinocytes while 1.25 mg/mL amikacin and 0.034 mg/mL colistin do not affect fibroblasts' viability and cytokine secretion but have an impact on keratinocytes. These concentrations are above the minimum inhibitory concentration but only amikacin could eradicate the biofilm. For the other antibiotics, cytotoxic concentrations are needed to eradicate the biofilm. Combinations with colistin at non-cytotoxic concentrations effectively eliminate the biofilm. These results provide information about the concentrations required when administering topical antibiotic treatments on skin lesions, and how these antibiotics affect wound management therapies. This study set the basis for the development of novel antibacterial wound healing strategies such as antibiotic artificial skin substitutes.

Assessing the Efficacy of PLGA-Loaded Antimicrobial Peptide OH-CATH30 Microspheres for the Treatment of Bacterial Keratitis: A Promising Approach

Bacterial keratitis in animals presents challenges due to ocular structural barriers, hindering effective drug delivery. In this study, we used biocompatible and biodegradable poly(lactic-co-glycolic acid) (PLGA) to encapsulate the naturally occurring antimicrobial peptide OH-CATH30, an alternative to conventional antibiotics, for the treatment of bacterial keratitis in animals. Microspheres (MS) were prepared using a modified water-in-oil-in-water (W/O/W) double-emulsion method with optimized osmotic pressure. We conducted comprehensive evaluations, including in vitro characterization, encapsulation efficiency determination, in vitro release kinetics, and in vivo/vitro assessments of irritation and bacterial inhibition. The optimized method yielded microspheres with impressive encapsulation efficiency of 75.2 ± 3.62% and a loading capacity of 18.25 ± 5.73%, exhibiting a well-defined particle size distribution (200-1000 nm) and a ζ-potential of -17.3 ± 1.91 mV. The microspheres demonstrated initial burst release followed by sustained and controlled release in vitro. Both in vitro and in vivo tolerance tests confirmed the biocompatibility of the drug-loaded microspheres, as they did not elicit significant irritation in ocular tissues. Remarkable antibacterial effects were observed in both in vitro and in vivo experiments. Our developed PLGA microspheres show promise as an alternative therapeutic option for topical administration in managing keratitis, offering exceptional drug delivery capabilities, improved bioavailability, and potent antibacterial efficacy.

Exploration of Lipid-Based Nanocarriers as Drug Delivery Systems in Diabetic Foot Ulcer

Diabetes mellitus is a chronic manifestation characterized by high levels of glucose in the blood resulting in several complications including diabetic wounds and ulcers, which predominantly require a longer duration of treatment and adversely affect the quality of life of the patients. Nanotechnology-based therapeutics (both intrinsic and extrinsic types) have emerged as a promising treatment in diabetic foot ulcer/chronic wounds owing to their unique characteristics and specific functional properties. In this review, we have focused on the significance of the use of lipids in the healing of diabetic ulcers, their interaction with the injured skin, and recent trends in lipid-based nanocarriers for the healing of diabetic wounds. Lipid nanocarriers are also being investigated for gene therapy in diabetic wound healing to encapsulate nucleic acids such as siRNA and miRNA, which could silence the expression of inflammatory cytokines overexpressed in chronic wounds. Additionally, these are also being explored for encapsulating proteins, peptides, growth factors, and other biological genetic material as therapeutic agents. Lipid-based nanocarriers encompassing a wide variety of carriers such as liposomes, niosomes, ethosomes, solid lipid nanoparticles, and lipidoid nanoparticles that are explored for the treatment of foot ulcers supplemented with relevant research studies have been discussed in the present review. Lipid-based nanodrug delivery systems have demonstrated promising wound healing potential, particularly in diabetic conditions due to the enhanced efficacy of the entrapped active molecules.

Preparation, in vitro release and antibacterial activity evaluation of rifampicin and moxifloxacin-loaded poly(D,L-lactide-co-glycolide) microspheres

Osteomyelitis is difficult to treat because infective bone is poorly accessible for intravenously administering antibiotics and biofilm formation increases bacterial resistance. In this study, microspheres prepared using poly(lactide-co-glycolide) (PLGA) and embedded with moxifloxacin (MOX-PLGA microspheres) and rifampicin/moxifloxacin (RIF/MOX-PLGA microspheres) using the water-in-oil-in-water double emulsion solvent evaporation technique were used for local delivery. Shape of MOX-PLGA microspheres and RIF/MOX-PLGA microspheres were spherical, mean particle size of them were 20.52 μm and 16.62 μm, respectively. Encapsulation efficiency of the MOX-PLGA microspheres was 17.35% ± 2.42%. However, the encapsulation efficiency for MOX and RIF in RIF/MOX-PLGA microspheres was 33.25% ± 7.51% and 49.0% ± 11.25%, respectively. Moxifloxacin and rifampicin were released slowly from microspheres. Both microspheres can efficiently release antibiotics in vitro. Antibacterial and bacterial biofilm-inhibition properties of the released solution were investigated from RIF/MOX-PLGA, MOX-PLGA, and blank PLGA microspheres at varying time points in vitro. RIF/MOX-PLGA microspheres demonstrated the strongest antibacterial activity and bacterial biofilm-inhibition property than the other two microspheres (p < .05). This study suggests that the novel RIF/MOX-PLGA microspheres can be used as a promising carrier for osteomyelitis treatment.

Rumen tissue derived decellularized submucosa collagen or its chitosan-treated film as a cutaneous wound healant and 1H NMR-metabolite profiling of plasma

Developing an ideal wound dressing material for skin defects is of significant importance in a clinical emergency and is currently a global burden.

A new, bioactive, antibacterial-eluting, composite graft for infection-free wound healing

The current work focuses on the in vivo performance of a newly developed injectable composite graft in infected full-thickness wounds. The composite graft was composed of bioactive porous Poly dl-lactide-co-glycolide scaffolds, antibiotic gentamicin, and crosslinked gelatin as carrier gel. Treated infected wounds exhibited a faster wound closure, rapid weight gain, lower neutrophil count, higher breaking strength, and 100 times lesser microbial count (10(2) colony forming units/g in infected treated vs. 10(4)  colony forming units/g in infected control group) in comparison with infected control group 28 days post treatment. During healing, collagen production was more in the treated groups at day 7 than controls and thereafter gradually reduced to normal levels. Histology revealed a mature scar tissue formation, fibroblast proliferation, epidermal resurfacing, and collagen deposition in reticular alignment similar to normal healthy skin in treated wounds. Further, the plasma concentration of gentamicin was 35-45 μg/mL during the initial 12 hours and reduced to 1 μg/mL in 24 hours, which indicated safe levels of the antibiotic drug during healing. These results clearly indicate a faster, infection-free, and safe after treatment with the developed graft.