Melanin-Ce6-loaded polydopamine nanoparticles-based enhanced phototherapy for B16 melanoma cancer cells.

Melanoma is one of the most aggressive and lethal types of cancer owing to its metastatic propensity and chemoresistance property. An alternative therapeutic option is photodynamic and photothermal therapies (PDT/PTT), which employ near-infrared (NIR) light to generate heat and reactive oxygen species (ROS). As per previous reports, Melanin (Mel), and its synthetic analogs (i.e. polydopamine nanoparticles) can induce NIR light-mediated heat energy, thereby selectively targeting and ameliorating cancer cells. Similarly, chlorin e6 (Ce6) also has high ROS generation ability and antitumor activity against various types of cancer. Based on this tenet, In the current study, we have encapsulated Mel-Ce6 in a polydopamine (PDA) nanocarrier (MCP NPs) synthesized by the oxidation polymerization method. The hydrodynamic diameter of the synthesized spherical MCP NPs was 139 ± 10 nm. The MCP NPs, upon irradiation with NIR 690 nm laser for 6 min, showed photothermal efficacy of more than 50 °C. Moreover, the red fluorescence in the MCP NPs due to Ce6 can be leveraged for diagnostic purposes. Further, the MCP NPs exhibited considerable biocompatibility with the L929 cell line and exerted nearly 70% ROS-mediated cytotoxicity on the B16 melanoma cell line after the laser irradiation. Thus, the prepared MCP NPs could be a promising theranostic agent for treating the B16 melanoma cancer.

Lipid-coated red fluorescent carbon dots for imaging and synergistic phototherapy in breast cancer.

The synthesis of carbon dots using plant leaves is a facile and economically viable approach. Here we report the development of lipid-coated red fluorescent carbon dots (LRCDs), a biocompatible and stable nanomaterial, utilizing Clitoria ternatea leaves. The red fluorescent carbon dots (RCDs) were prepared by hydrothermal method, followed by lipid coating using rotary evaporation for imaging-guided phototherapy. RCDs generate heat in tandem with NIR laser irradiation and could therefore be employed as a photothermal agent in cancer therapy. Additionally, the fluorescent nature of RCDs can be utilized in bioimaging. The fabricated RCDs displayed a characteristic fluorescent emission maximum at 672 nm with a shoulder peak at 723 nm. Hydrophobicity is a major drawback associated with the RCDs, which limits their therapeutic efficiency due to poor biodistribution and rapid clearance. To address this limitation, we coated RCDs with soya lecithin to generate hydrophilic LRCDs with better bioavailability and therapeutic effectiveness. Further analysis using MTT assay reveals high biocompatibility and a distinct photothermal ablation potency of LRCDs against L929 and 4T1 cells, respectively. LRCDs could potentially be synthesized on a large scale and used for a variety of applications due to their low-cost, and biocompatibility.