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Abstract:
The human skin is highly susceptible to bacterial infections and inflammation when its integrity is disrupted. Treatment of infected wounds is a big challenge in modern medicine, and rising antibiotic resistance motivates the development of antibiotic-free therapies. Here, we present a stimuli-responsive wound dressing that integrates carboxylated eggshell membrane (ESM) with electrosprayed tannic acid/iron (TAFe) particles trapped between electrospun Poly-L-lactide-caprolactone (PLCL) layers and precisely laser-structured to increase porosity and fit the wound size. The TAFe exhibits stable photothermal conversion and antioxidant activity, eradicating more than 99.5% of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), while maintaining high biocompatibility in vitro. In an infected rat model, the sandwich-like ESMmod/PLCL/TAFe dressing accelerated closure and achieved near-complete healing, with residual wound area <1% by day 14. Analysis shows that the material promotes M2-mediated reparative microenvironment, which, in consequence, suppresses TNFα and IL-6, a pro-inflammatory cytokines, and enhances angiogenesis through increased CD31 and VEGF levels. Moreover, a more organized collagen structure and less scarring were found in the wound bed. Importantly, the material is partially derived from waste, aligning with circular economy principles and reducing resource burden. The versatile composite offers an antibiotic-free strategy that disinfects, modulates inflammation, and promotes regeneration of infected wounds.

Keywords:
circular economy, immunomodulated wound healing, laser-engineered microenvironment, macrophage polarization orchestration, photothermal anti-bacterial activity

Abstract:
Nanoparticles have attracted a great deal of attention as carriers for drug delivery to cancer cells. However, reports on their potential cytotoxicity raise questions of their safety and this matter needs attentive consideration. In this paper, for the first time, the cytotoxic effects of two carbon based nanoparticles, diamond and graphite, on glioblastoma and hepatoma cells were compared. First, we confirmed previous results that diamond nanoparticles are practically nontoxic. Second, graphite nanoparticles exhibited a negative impact on glioblastoma, but not on hepatoma cells. The studied carbon nanoparticles could be a potentially useful tool for therapeutics delivery to the brain tissue with minimal side effects on the hepatocytes. Furthermore, we showed the influence of the nanoparticles on the stable, fluorescently labeled tumor cell lines and concluded that the labeled cells are suitable for drug cytotoxicity tests.