Electrospining: Environmentally friendly antibacterial electrospun nanofiber membrane containing nano silver green synthesized from natural glycoprotein for healing of infected wounds

Background

Bacterial infections of skin wounds often cause difficult-to-heal wounds and have become a major public health challenge worldwide due to their high mortality and huge economic burden. Despite this, conventional antibiotics are currently limited in their application due to potential drug resistance, delayed hypersensitivity reactions, and repeated infections. Silver nanoparticles (Ag NPs) have the characteristics of small particle size and large specific surface area, and have strong broad-spectrum antibacterial effects. At the same time, high biosafety and low drug resistance have made Ag NPs an emerging antibacterial material in the fields of medical treatment and food processing. Currently, the biosynthesis of Ag NPs mediated by natural extracts such as polyphenols, flavonoids, terpenes, alkaloids, and polysaccharides is considered to be a green synthetic pathway and a current research hotspot. In our previous study, we found that a new glycoprotein from the ancient medicinal insect American cockroach (Periplaneta americana L.PAGP) significantly promoted wound healing by regulating macrophage polarization. Interestingly, a certain amount of reducing groups on PAGP, such as aldehyde, phenolic hydroxyl, thiol, and thioether bonds, promoted the potential of preparing Ag NPs as reducing agents and stabilizers. As a proof-of-concept, here we used PAGP not only to prepare eco-friendly Ag NPs but also as a wound healing material.

The main point of this paper

Application of existing wound dressings:

Wound dressings such as gauze, hydrocolloid, transparent film, foam, and hydrogel have been widely used in wound healing. Their main function is to act as a physical barrier, absorb secretions, and promote healing.

Advantages of multifunctional dressings:

Multifunctional dressings that inhibit bacterial infection, reduce dressing changes, and repair damaged tissues have better application advantages in clinical practice.

Potential of electrospinning nanofiber films:

Electrospinning nanofiber films have great potential in promoting wound healing due to their unique bionic nanofiber structure, high porosity, and high specific surface area.

Combination of PAGP and PVA:

PAGP (polyamino acid) cannot be used directly for electrospinning, and needs to be blended with spinnable polymers such as polyvinyl alcohol (PVA) to prepare nanofibers.

Characteristics of PVA:

PVA is a synthetic polymer commonly used in the preparation of nanofiber dressings. It has excellent electrospinnability, biocompatibility, biodegradability, hydrophilicity, and supports cell adhesion, proliferation, and migration.

Preparation of Ag NPs@PP membrane:

In this study, PAGP, antibacterial silver nanoparticles (Ag NPs) and PVA were mixed and a composite nanofiber membrane was prepared by electrospinning technology, named Ag NPs@PP membrane.

A novel nanofiber dressing to promote healing of infected wounds: Study on silver nanoparticle-embedded PAGP nanofiber membrane

Clinical Challenges of Wound Infection:

Bacterial wound infection may lead to delayed healing and severe tissue damage, which is a major problem in clinical treatment.

Limitations of Traditional Treatment Methods:

Traditional treatment methods and wound dressings cannot achieve the ideal antibiotic activity and accelerate wound healing.

Discovery and Application of PAGP:

Studies have found that glycoprotein (PAGP) extracted from the medicinal animal insect American cockroach has a significant promoting effect on wound healing.

Green Synthesis of Ag NPs:

Silver nanoparticles (Ag NPs) were prepared by a PAGP-mediated green synthesis method.

Preparation of Ag NPs@PP membrane:

Environmentally friendly PAGP nanofiber membrane (Ag NPs@PP membrane) embedded with silver nanoparticles was prepared by electrospinning.

Summary

In this study, we successfully used natural American cockroach glycoprotein (PAGP) to reduce AgNO3 and prepared ultrasmall Ag NPs (8.8±2.8nm) with high dispersibility and stability. Combining the significant antibacterial properties of Ag NPs and the activity of PAGP in promoting wound healing, an environmentally friendly PAGP nanofibrous membrane embedded with Ag NPs (Ag NPs@PP membrane) was further prepared by electrospinning technology. In vitro studies showed that the Ag NPs@PP membrane had good mechanical properties, biocompatibility, promoted macrophage M2 polarization, and had strong antibacterial effects against Staphylococcus aureus and Escherichia coli. The Ag NPs@PP membrane was topically applied to a rat wound model of fecal bacterial infection, which could significantly inhibit bacterial growth and accelerate wound healing by promoting TGF-β1 expression and collagen regeneration.