Enhancing photodynamic therapy for cutaneous squamous cell carcinoma with ACP-U soluble microneedles

Photodynamic therapy (PDT) is recognized as a promising treatment for cutaneous squamous cell carcinoma (cSCC). The effectiveness of PDT is limited due to the skin barrier and cell membrane impeding the delivery of the photosensitizer and molecular oxygen levels at the treatment site. In this study, ulvan microneedles were loaded with poly(lactic-co-glycolic acid) (PLGA) nanoparticles, encapsulating 5-aminolevulinic acid (ALA) and catalase (CAT). The results showed that the ALA-CAT-PLGA-Ulvan (ACP-U) microneedles were successfully synthesized and were able to penetrate the skin efficiently, dissolve quickly, and subsequently release the ACP nanoparticles to the target site. With good biocompatibility both in vitro and in vivo, ACP-U microneedles significantly enhanced the antitumor effect of PDT in A431 cells and tumor-bearing mice model. Therefore, this study presents a promising transdermal delivery approach for photosensitizers in the PDT of cSCC.