Co-Administration of Chemo-Phototherapeutic Loaded Lignin Nanoarchitecture for the Treatment of Skin Cancer Cell Lines and Bacterial Infections

Epidermoid carcinoma is the utmost frequent type of skin cancer worldwide resulting in bacterial infection-induced chronic wounds. The primary available treatment option is surgery and subsequent skin transplantation, which is challenging in terms of associated pain, full cure, skin regeneration, and cost. Combinatorial chemo-phototherapy involving photodynamic therapy and chemotherapy can be a potential treatment for skin cancers and associated chronic wounds. Herein, we devised a multidrug-loaded nanoformulation (RB@CPT-LNPs) by encapsulating Camptothecin (CPT, a chemotherapeutic agent) into biocompatible lignin nanoparticles (LNPs), followed by surface conjugation with Rose Bengal (RB, a photosensitizer). The RB@CPT-LNPs were found to be highly stable (polydispersity, <0.3) in an aqueous solution with size and Zeta potential 170 nm and -14.7 mV, respectively. The RB@CPT-LNPs showed efficient reactive oxygen species generation (Phi(Delta), 0.74) in vitro when activated by light. Importantly, RB@CPT-LNPs showed augmented anticancer activity in skin cancer cells (A431) upon 525 nm laser irradiation compared with a single treatment (photodynamic therapy or chemotherapy). Further, the formulation also showed high photodynamic antimicrobial activity against both Gram-positive and Gram-negative bacteria. Therefore, the developed RB@CPT-LNP formulation could offer an effective strategy for the elimination of skin cancer and skin-tumor-induced chronic wounds.