Enhanced photodynamic therapy of cancer using porphyrin-based nanoparticles synthesized <i>via</i> the co-precipitation method

Photodynamic therapy (PDT) is a minimally invasive treatment modality that offers an alternative or supplementary approach to chemotherapy and surgery, characterized by low toxicity and reduced side effects. PDT has been applied to various cancers, often in combination with other therapies to enhance its efficacy. The therapy relies on three main components: a photosensitizer (PS), light of a specific wavelength, and molecular oxygen (O₂). Porphyrins are commonly used PSs due to their favorable properties, but their hydrophobic nature leads to aggregation, reducing their therapeutic effectiveness. To address these challenges, we have synthesized porphyrin-based nanoparticles (PNPs) using a co-precipitation method. Three types of porphyrins, tetraphenylporphyrin (TPP), 5-(4-aminophenyl)-10,15,20-triphenyl porphyrin (ATPP), and polyhedral oligomeric silsesquioxane (POSS)-ATPP, were encapsulated in the nanoparticles. The structural properties of the PNPs were characterized using scanning electron microscopy (SEM), dynamic light scattering (DLS), and <i>ζ</i>-potential measurements. <i>In vitro</i> studies in cervical cancer (HeLa) and triple-negative breast cancer (MDA-MB-231) cell lines demonstrated improved internalization and phototherapeutic effects of the PNPs compared to the parent porphyrins. Our findings suggest that encapsulating porphyrins in nanoparticles enhances their photodynamic therapy efficacy, offering a promising approach for cancer treatment.