Designing Lignin-Based Nanophotocomposites as Reactive Oxygen Species Generators for Inactivating Candida Strains

A combination of sustainable resources and precision biotherapeutics is a game changer for affordable healthcare. A natural biopolymer, lignin, present in agri-biomass, can serve as a nanodrug carrier for targeted delivery. Photodynamic therapy (PDT) is a noninvasive tool to accomplish targeted delivery. Photosensitizers, which are frequently used macrocycles in PDT, lack sufficient hydrophilicity for biological applications. In this regard, lignin-derived nanocarriers provide a sustainable solution, imparting bioavailability to the photosensitizers. In this study, a series of metalloporphyrins were designed and converted into lignin-based nanophotocomposites to augment their photostability and biological efficacy. Such nanophotocomposites played a significant role in eradicating candida infection via PDT by generating reactive oxygen species upon light irradiation. Computational studies (time-dependent density functional theory) established good photosensitizing properties of the metalloporphyrins. These nanophotocomposites demonstrated a pH-triggered release of photosensitizer drugs. The lignin-based nanophotocomposites could be used as low-cost, light-assisted treatment probes for curing candida infections.