Hui Yu,Xiaojing Chen,Jie Cai,Dongdong Ye,Yuxiao Wu,Peifeng Liu
Long-term antibacterial medical dressings can prevent infection as skin wounds heal. In this study, we used the hydrophobic antibacterial drug amoxicillin as a model to prepare drug-loaded nanomicelles using a film dispersion–hydration method, and drug-loaded nanomicelles were coaxially electrospun into nanofiber to create a novel nanomicelle-in-nanofiber (NM-in-NF) drug delivery system. Scanning electron microscopy and transmission electron microscopy were used to characterize the morphology of nanomicelles and nanofibers. Thermal property of as-prepared samples was tested using differential scanning calorimetry. The drug release behavior, cytotoxicity, and antibacterial properties of NM-in-NFs were examined in vitro to evaluate the system’s potential to be used in the treatment of skin wounds. Experimental results indicated that the novel NM-in-NF system had dual controlled release effect, which greatly reduced burst release and prolonged effective drug duration. Moreover, NM-in-NFs was also found to be safe and non-toxic, with a broad-spectrum antibacterial activity. It thus could potentially be used in long-term antibacterial medical dressings to treat skin wounds.
Hydrogel-based wound dressings are ideal materials as they could provide a moist environment to promote wound healing. Silk sericin is a natural macromolecular protein produced by silkworms and has positive effects on fibroblasts and keratinocytes. Sodium alginate is a natural polysaccharide known as a mouldable matrix. To develop novel hydrogel wound dressings, sodium alginate was functionalized with silk sericin to yield an injectable and mouldable semi-interpenetrating network hydrogel (SA/Se) using calcium ions as the crosslinking agents. Meanwhile, silver nanoparticles (AgNPs) were synthesized in situ by the phenolic hydroxyl group of tyrosine in sericin to enhance the antibacterial activity of the hybrid hydrogel. UV–visible spectroscopy, fluorescence spectroscopy, transmission electron microscope, X-ray photoelectron spectroscopy and energy dispersive spectroscopy demonstrated the successful synthesis of AgNPs with average size of 15.7 nm in SA/Se-Ag0.2. Field emission scanning electron microscopy showed the macroporous structure of the hydrogel. The hybrid hydrogel had a swelling ratio of 32 and more than 5% of retention ratio after 50 h. It exhibited effective antibacterial activity through irreversibly disrupting bacterial membrane structure to result in bacterial lysis and death. Cell counting kit-8 assay suggested the hybrid hydrogel was highly cytocompatible. The animal experiment showed the wound contraction ratio in SA/Se-Ag0.2 group was 99% after 12 days, indicating it can effectively promote wound healing. This novel hydrogel is promising for wound healing and tissue engineering.
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