The skin is the largest organ of the human body and is responsible for many essential bodily functions. With the increasing economic activities of humans and the damage to the ozone layer, the number of skin cancer patients is rising annually. Most genes and drugs cannot penetrate the stratum corneum of the skin, which prevents complete and irreversible tumor treatment. Microneedles are considered a minimally invasive method that can easily pass through the stratum corneum and deliver drugs and genes to the target tissue. Additionally, other therapeutic methods, such as photothermal therapy, have been combined with drug- or gene-loaded microneedles to enhance their therapeutic effects. In this study, polymer-based microneedles were combined with the anticancer drug doxorubicin and a photothermal agent, such as two-dimensional bismuth nanoparticles, for the treatment of superficial skin tumors. Two-dimensional bismuth nanoparticles are an ideal choice for photothermal therapy due to their large surface area for light absorption. In this research, bismuthene was first synthesized using liquid-phase exfoliation. Its chemical, structural, morphological, and optical properties were then eva‎luated. Photothermal properties were assessed by laser irradiation at a wavelength of 808 nm and a power of 1.5 W/cm². Subsequently, bismuthene at concentrations of 1% and 2% by weight was incorporated into microneedles made of a polymer composite of polyvinyl alcohol and chitosan in equal weight percentages, along with doxorubicin. Antibacterial properties, adhesion to the skin, antibacterial efficacy, and cell death pathways were eva‎luated through various tests. Results showed that bismuthene was synthesized with a thickness of 18 nm and a bismuth content of 85.57% by weight. Optical properties indicated its ability to capture near-infrared light. Additionally, as the thickness of the sheets decreased, the bandgap increased. Temperature changes after 10 minutes of laser irradiation at 808 nm exceeded 25°C, demonstrating the desirable efficiency of the synthesized bismuthene. The nanocomposite containing 1% by weight of bismuthene exhibited good biocompatibility and antibacterial properties and was subjected to further eva‎luations. After 8 minutes of laser irradiation at 808 nm, its temperature reached 44°C, which represented an approximate 10°C increase compared to control microneedles. Flow cytometry results indicated that apoptosis in cancer cells reached 58.5% following laser irradiation of microneedles containing 1% bismuthene, which increased to 95.5% with the addition of the drug. This study highlights the potential use of two-dimensional nanoparticles in photothermal therapy and the necessity of optimizing their applications in medical treatments.

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نفيسه اسمعيل

نرگس جوهري , افسانه فخار