Topical colloidal indocyanine green-mediated photodynamic therapy for treatment of basal cell carcinoma

Abstract

Indocyanine green (ICG) is a near-IR fluorescent dye with a great potential for application as photosensitizer in topical photodynamic therapy (PDT) of skin diseases. Despite its merits, its use has been hampered by its high degradation rate. Therefore, in the current article, ICG was encapsulated in a vesicular colloidal nanocarrier (transfersomes), with the aim of enhancing its therapeutic efficacy. Transfersomes were characterized for their entrapment efficiency, particle size, zeta potential, morphology, in vitro release and histopathological effect on mice skin. A pilot clinical study was conducted to test its therapeutic potential for PDT of basal cell carcinoma (BCC). Transfersomal ICG displayed particle size (∼125 nm) and a negative zeta potential (∼-31 mV). Transfersomes were also able to sustain the release of ICG >2 h. Upon incorporation of transfersomal ICG in gel form, it was found to maintain the normal histology of mice skin post-irradiation with diode laser 820 nm. Moreover, ICG transfersomal PDT achieved 80% clearance rate for BCC patients with minimal pain reported during treatment. The previous findings suggest that transfersomal nanoencapsulated ICG is a promising treatment modality for BCC.