The emergence of antibiotic-resistant bacteria, particularly the most hazardous pathogens, namely Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. (ESKAPE)-pathogens pose a significant threat to global health. Current antimicrobial therapies, including those targeting biofilms, have shown limited effectiveness against these superbugs. Nanoparticles, specifically silver nanoparticles (AgNPs), have emerged as a promising alternative for combating bacterial infections. In this study, two types of AgNPs with different physic-chemical properties were evaluated for their antimicrobial and antibiofilm activities against clinical ESKAPE strains. Two types of silver nanoparticles were assessed: spherical silver nanoparticles (AgNPs-1) and cubic-shaped silver nanoparticles (AgNPs-2). AgNPs-2, characterized by a cubic shape and higher surface-area-to-volume ratio, exhibited superior antimicrobial activity compared to spherical AgNPs-1. Both types of AgNPs demonstrated the ability to inhibit biofilm formation and disrupt established biofilms, leading to membrane damage and reduced viability of the bacteria. These findings highlight the potential of AgNPs as effective antibacterial agents against ESKAPE pathogens, emphasizing the importance of nanoparticle characteristics in determining their antimicrobial properties. Further research is warranted to explore the underlying mechanisms and optimize nanoparticle-based therapies for the management of infections caused by antibiotic-resistant bacteria.

Electrospinning, a technique for creating fabric materials from polymer solutions, is widely used in various fields, including biomedicine. The unique properties of electrospun fibrous membranes, such as large surface area, compositional versatility, and customizable porous structure, make them ideal for advanced biomedical applications like tissue engineering and wound healing. By considering the high biocompatibility and well-known regenerative potential of polylactic acid (PLA) and chitosan (CH), as well as the versatile antibacterial effect of silver nanoparticles (AgNPs), this study explores the antibacterial efficacy, adhesive properties, and cytotoxicity of electrospun chitosan membranes with a unique nanofibrous structure and varying concentrations of AgNPs. Silver nanoparticles incorporated at concentrations of 25-50 μg/mL or above significantly enhanced the antibacterial effectiveness, especially against Staphylococcus aureus and Escherichia coli. Biocompatibility assessments using umbilical cord mesenchymal stem cells demonstrated the nontoxic nature of the membranes with an AgNP concentration of 12.5 μg/mL, underscoring their potential for biomedical applications. This study provides valuable insights into developing electrospun chitosan membranes as effective antimicrobial coatings for various biomedical uses, including wound healing patches and tissue engineering constructs for soft tissue replacement.

This study addresses the need for enhanced antimicrobial properties of electrospun membranes, either through surface modifications or the incorporation of antimicrobial agents, which are crucial for improved clinical outcomes. In this context, chitosan—a biopolymer lauded for its biocompatibility and extracellular matrix-mimicking properties—emerges as an excellent candidate for tissue regeneration. However, fabricating chitosan nanofibers via electrospinning often challenges the preservation of their structural integrity. This research innovatively develops a chitosan/polycaprolactone (CH/PCL) composite nanofibrous membrane by employing a layer-by-layer electrospinning technique, enhanced with silver nanoparticles (AgNPs) synthesized through a wet chemical process. The antibacterial efficacy, adhesive properties, and cytotoxicity of electrospun chitosan membranes were evaluated, while also analyzing their hydrophilicity and nanofibrous structure using SEM. The resulting CH/PCL-AgNPs composite membranes retain a porous framework, achieve balanced hydrophilicity, display commendable biocompatibility, and exert broad-spectrum antibacterial activity against both Gram-negative and Gram-positive bacteria, with their efficacy correlating to the AgNP concentration. Furthermore, our data suggest that the antimicrobial efficiency of these membranes is influenced by the timed release of silver ions during the incubation period. Membranes incorporated starting with AgNPs at a concentration of 50 µg/mL effectively suppressed the growth of both microorganisms during the early stages up to 8 h of incubation. These insights underscore the potential of the developed electrospun composite membranes, with their superior antibacterial qualities, to serve as innovative solutions in the field of tissue engineering.

The present study demonstrates a strategy for preparing porous composite fibrous materials with superior biocompatibility and antibacterial performance. The findings reveal that the incorporation of PEG into the spinning solutions significantly influences the fiber diameters, morphology, and porous area fraction. The addition of a hydrophilic homopolymer, PEG, into the Ch/PLA spinning solution enhances the hydrophilicity of the resulting materials. The hybrid fibrous materials, comprising Ch modified with PLA and PEG as a co-solvent, along with post-treatment to improve water stability, exhibit a slower rate of degradation (stable, moderate weight loss over 16 weeks) and reduced hydrophobicity (lower contact angle, reaching 21.95 ± 2.17°), rendering them promising for biomedical applications. The antibacterial activity of the membranes is evaluated against Staphylococcus aureus and Escherichia coli, with PEG-containing samples showing a twofold increase in bacterial reduction rate. In vitro cell culture studies demonstrated that PEG-containing materials promote uniform cell attachment, comparable to PEG-free nanofibers. The comprehensive evaluation of these novel materials, which exhibit improved physical, chemical, and biological properties, highlights their potential for biomedical applications in tissue engineering and regenerative medicine.

This study investigates the development and application of electrospun wound dressings based on polylactic acid (PLA) nanofibers, chitosan, and copper nanoparticles (CuNPs) for the treatment of purulent skin wounds. The materials were evaluated for their structural, antibacterial, and wound healing properties using an animal model. PLA/Ch-CuNPs demonstrated the most significant antibacterial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, surpassing the other tested materials. The integration of CuNPs into the nanofiber matrices not only enhanced the antimicrobial efficacy but also maintained the structural integrity and biocompatibility of the dressings. In vivo experiments using a rat model showed that PLA/Ch-CuNPs facilitated faster wound healing with reduced exudative and inflammatory responses compared to PLA alone or PLA-CuNPs. Histological and immunohistochemical assessments revealed that the combination of PLA, chitosan, and CuNPs mitigated the inflammatory processes and promoted tissue regeneration more effectively. However, this study identified potential toxicity related to copper ions, emphasizing the need for careful optimization of CuNP concentrations. These findings suggest that PLA/Ch-CuNPs could serve as a potent, cost-effective wound dressing with broad-spectrum antibacterial properties, addressing the challenge of antibiotic-resistant infections and enhancing wound healing outcomes.

Biomaterials modified by antibacterial substances, including nanoparticles, open new opportunities for the effective treatment of infected wounds. Unfortunately, most publications focused only on experiments in vitro, with limited understanding of their potential for the clinic. This study evaluates the effectiveness in vivo of electrospun chitosan/polylactic acid (Ch/PLA) membranes enriched with silver nanoparticles (AgNPs) for purulent wound treatment. The composite biomaterial integrates chitosan’s biocompatibility and antimicrobial activity with PLA’s structural integrity, while AgNPs enhance antibacterial efficacy against major wound pathogens, including Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia aureus. A full-thickness purulent wound model was established in a rat model, and the animals were divided into three treatment groups: (i) Ch/PLA, (ii) Ch/PLA-AgNPs, and (iii) PLA-chlorhexidine (control). Wound healing was monitored over 21 days through macroscopic evaluation, histology, immunohistochemistry, and microbiological analysis. The Ch/PLA-AgNPs membranes significantly reduced bacterial colonization within 4–6 days, promoted granulation tissue formation, and accelerated epithelialization compared to the non-modified Ch/PLA scaffold. By day 15, complete wound closure was observed in the Ch/PLA-AgNPs group, comparable to PLA-chlorhexidine-treated wounds. Immunohistochemical analysis revealed a controlled inflammatory response with a balanced macrophage M1/M2 transition, supporting efficient tissue regeneration. Furthermore, systemic toxicity assessments indicated no significant adverse effects on internal organs. These findings demonstrate that electrospun Ch/PLA-AgNPs membranes effectively accelerate purulent wound healing by combining antimicrobial protection with biocompatible tissue support. This innovative approach presents a promising alternative to conventional wound dressings and paves the way for clinical applications in managing infected wounds.