Fabrication of Multifunctional Wound Dressing Composite Biomaterials Composed of Ag/Mg-Hydroxyapatite Doped Electrospun Poly (Vinyl Alcohol) Nanofibers for Skin Tissue Regeneration

Synthesis of Cross-Linked and Sterilized Water-Soluble Electrospun Nanofiber Biomatrix of Streptomycin-Imbedded PVA/CHN/β-CD for Wound Healing

The diagnosis and prognosis of chronic wounds are demanding and require objective assessment. Because of their potential medicinal applications, the syntheses of biopolymeric chitosan (CHN) structure and PVA-based mixed electrospun nanofibers with biomimetic features were thoroughly investigated. This study created different formulas, including a guest molecule and capping agent, using supporting PVA as a vehicle. CHN was used as a biomodifier, and beta-cyclodextrin (ß-CD) as a smoother and more efficiently entraps streptomycin (STP) compared with the silver sheet wound dressing. The relevant analyses showed that the size distribution increased with the incorporation of PVA, CHN, and ß-CD to 120.3, 161.9, and 192.02 nm. The webs boosted particle size and released content stability to 96.4% without compromising the nanofiber structure. Examining the synergistic effects of the PVA/CHN/STP/ß-CD nanoformulation against pathogenic strains of S. aureus, P. aeruginosa, and Aspergillus niger, clean zones were 47 ± 3.4, 45 ± 3.0, and 49 ± 3.7 mm were produced. PVA/CHN/STP/ß-CD formula exhibited a 98.9 ± 0.6% cell viability and wound closure of 100% at 72 h. The results reveal that the PVA/CHN/STP/ß-CD formula is promising for medical applications, especially in wound healing, compared with the silver sheet.

Synergistic amalgamation of shellac with self-antibacterial hydroxyapatite and carboxymethyl cellulose: An interactive wound dressing for ensuring safety and efficacy in preliminary in vivo studies

This study focuses on the synergistic formulation of environmentally friendly blended materials based on carboxymethyl cellulose (CMC) for advanced interactive wound dressing. New CMC hydrogels were prepared with two degrees of functionalization and chemically crosslinked with citric acid (CA) to fine-tune their properties. Additionally, CMC-based hybrids were created by blending with shellac (SHL) and incorporating self-antibacterial hydroxyapatite (HA) to inhibit bacterial growth and promote wound healing. The results demonstrate the successful production of superabsorbent hydrogels with typical swelling degrees ranging from 81% in water to 82% in phosphate-buffered saline (PBS). These hydrogels exhibit distinct morphological features and remarkable improvements in surface mechanical properties, specifically in their tensile properties, which show a significant increase from approximately 0.03 to 2.2 N/mm2 due to the formation of CMC-SHL-HA hybrid nanostructures. Furthermore, the cytocompatibility of these CMC-based hydrogels was investigated by assessing the in vitro cell viability responses of human skin fibroblasts. The results reveal the cell viability responses over 91%, indicating their biocompatibility with human cells. Moreover, the characteristics of surgical wounds were assessed before and after the application of the hydrogel on dogs, and no signs of infection were observed at any of the surgical sites post-surgery.

Enhanced photocatalytic and antibacterial activities of novel Ag-HA bioceramic nanocatalyst for waste-water treatment

Hydroxyapatite (HA), the most common bioceramic material, offers attractive properties as a catalyst support. Highly crystalline mono-dispersed silver doped hydroxyapatite (Ag-HA) nanorods of 60 nm length was developed via hydrothermal processing. Silver dopant offered enhanced chemisorption for crystal violet (CV) contaminant. Silver was found to intensify negative charge on the catalyst surface; in this regard enhanced chemisorption of positively charged contaminants was accomplished. Silver dopant experienced decrease in the binding energy of valence electron for oxygen, calcium, and phosphorous using X-ray photoelectron spectroscopy XPS/ESCA; this finding could promote electron-hole generation and light absorption. Removal efficiency of Ag-HA nanocomposite for CV reached 88% after the synergistic effect with 1.0 mM H2O2; silver dopant could initiate H2O2 cleavage and intensify the release of active ȮH radicals. Whereas HA suffers from lack of microbial resistance; Ag-HA nanocomposite demonstrated high activity against Gram-positive (S. aureus) bacteria with zone of inhibition (ZOI) mm value of 18.0 mm, and high biofilm inhibition of 91.1%. Ag-HA nanocompsite experienced distinctive characerisitcs for utilization as green bioceramic photocatalyst for wastewater treatment.

Antimicrobial, and Antibiofilm Activities of Silver Doped Hydroxyapatite: A Novel Bioceramic Material for Dental Filling

Even though hydroxyapatite (HA) is the most common biocompatible material; it has limited antibacterial resistance. HA experiences a tailor-made structure depending on the desired applications. In this regard, silver (Ag) is of particular interest to inhibit wide spectrum of pathogenic bacteria and other microorganisms. Silver doped hydroxyapatite (Ag-HA) was developed via wet co-precipitation with subsequent hydrothermal processing to hinder the growth and multiplication of pathogenic microbes. Ag-HA demonstrated mono-dispersed nano-rods of 70 nm length and 7 nm diameters. Even though silver dopant induced stresses within the crystal lattice; Ag-HA maintained the crystallographic structure of HA with no change. Ag-HA nanocomposite demonstrated Ca/P value of 1.238 compared with 1.402 for virgin HA via XPS spectroscopy. The reduction of Ca/P value was correlated to the partial replacement of Ca+2 with Ag+1; Silver content was reported to be of 1 atomic %. Elemental mapping using EDAX confirmed uniform dispersion of silver ion within HA lattice. Antimicrobial results indicated that, Ag-HA nanocomposite demonstrated the most potent zone of inhibition (ZOI) against Staphylococcus aureus, and Candida albicans. Antibiofilm results indicated that Ag-HA nanocomposite at 10.0 µg/mL, experienced the highest percentage for S. aureus and C. albicans of 96.09%, and 77.77%, respectively. Ag-HA nanocomposite demonstrated an excellent disinfectant agent once it had excited by UV light. In growth curve assay, the OD600 value of Ag- HA were lower, showing the repression impact on the growth of S. aureus. It was observed that the quantity of cellular protein discharged from S. aureus is directly proportional to the concentration of Ag-HA, which proves the antibacterial characteristics of the Ag-HA nanocomposite, and explains the creation of holes in the bacterial membrane producing the oozing out of the proteins from the S. aureus cytoplasm. Ag-HA nanocomposite achieved the complete lysis of the bacterial cell and cell malformation, decreasing the total viable number, so the outstanding antimicrobial results encouraged the tooth filling biomedical applications.

Graphical Abstract