High-Performance Photodynamic Therapy of Tongue Squamous Cell Carcinoma with Multifunctional Nano-Verteporfin

Background: The photodynamic therapy (PDT) showed promising potential in treating tongue squamous cell carcinoma (TSCC). The Food and Drug Administration approved Verteporfin (Ver) is a powerful alternative in this field for its penetrating power and high production of reactive oxygen species (ROS). However, its applications in the treatment of TSCC are still rare. Methods: Ver was loaded onto Poly (lactic-co-glycolic acid) (PLGA) nanoparticles, followed by the modification with RGD peptide as the ligand. The nanostructured was named as RPV. In vitro assessments were conducted to evaluate the cytotoxicity of RPV through the Live/Dead assay analysis and Cell Counting Kit-8 (CCK-8) assay. Using the reactive oxygen species assay kit, the potential for inducing targeted tumor cell death upon laser irradiation by promoting ROS production was investigated. In vivo experiments involved with the biological distribution of RPV, the administration with RPV followed by laser irradiation, and the measurement of the tumor volumes. Immunohistochemical analysis was used to detect the Ki-67 expression, and apoptosis induced by RPV-treated group. Systemic toxicity was evaluated through hematoxylin-eosin staining and blood routine analysis. Real-time monitoring was employed to track RPV accumulation at tumor sites. Results: The in vitro assessments demonstrated the low cytotoxicity of RPV and indicated its potential for targeted killing TSCC cells under laser irradiation. In vivo experiments revealed significant tumor growth inhibition with RPV treatment and laser irradiation. Immunohistochemical analysis showed a notable decrease in Ki-67 expression, suggesting the effective suppression of cell proliferation, and TUNEL assay indicated the increased apoptosis in the RPV-treated group. Pathological examination and blood routine analysis revealed no significant systemic toxicity. Real-time monitoring exhibited selective accumulation of RPV at tumor sites. Conclusion: The findings collectively suggest that RPV holds promise as a safe and effective therapeutic strategy for TSCC, offering a combination of targeted drug delivery with photodynamic therapy. Keywords: photodynamic therapy, verteporfin, RGD sequence, tumor-specific drug delivery