Highly Stable PLA/Gelatin Bionanocomposites for Enhanced Delivery of Chloroaluminum Phthalocyanine for Photodynamic Therapy against SK-MEL-28 Cells

Abstract This study reports the development of a biodegradable poly(lactic acid) and gelatin (nPLA-G) bionanocomposite as a drug delivery system for chloroaluminum phthalocyanine (ClAlPc) in photodynamic therapy (PDT). Using a hybrid desolvation/emulsification technique, we engineered spherical nanoparticles with an average diameter of 753.3 nm and a positive zeta potential of +8.90 mV. ClAlPc-loaded nanoparticles (nPLA-G/ClAlPc) were prepared using the same process, with a mean diameter of 809.3 nm and a zeta potential of +16.10 mV. The system achieved an exceptional encapsulation efficiency of 90.89% and maintained colloidal stability for over 270 days. In vitro assays showed a pH-dependent release profile, optimizing drug availability in tumoral microenvironments. The nPLA-G/ClAlPc system showed no dark toxicity but reached 97% cytotoxicity in SK-MEL-28 melanoma cells upon light activation (1.0 μmol L–1). These preliminary results demonstrate that the bionanocomposite effectively overcomes ClAlPc hydrophobicity, serving as a promising drug delivery system with preliminary photodynamic efficacy in vitro.