Porphyrin-xylan-coated silica nanoparticles for anticancer photodynamic therapy.

Porphyrins are widely used in anticancer photodynamic therapy (PDT). However, low physiological solubility and lack of selectivity towards cancer cells are the main limitations of their clinical use. Nanoparticles are being intensively explored as photosensitizer carriers for PDT to overcome these limitations. The aims of this work are to synthesize core-shell hybrid nanoparticles formed by a silica core and xylan carrying a 5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin (TPPOH) shell, and evaluate their anticancer activity. To afford drug-controlled incorporation and enhance blood circulation, TPPOH was covalently linked to xylan. Different xylans with degrees of substitution in TPPOH ranging from 0.034 to 1.11, were obtained and characterized. Then, the xylan-TPPOH conjugate (PX) was used to coat the silica nanoparticles (PX SNPs). The obtained nano-objects were characterized and their therapeutic potential for photodynamic therapy evaluated against colorectal cancer cell lines. in vitro analysis showed that PX SNPs were 40-fold and 10-fold more effective against HCT116 cells and HT-29 cells respectively compared to free TPPOH.