Gelatin nanoparticles via template polymerization for drug delivery system to photoprocess application in cells.

Photodynamic therapy (PDT) is a clinical treatment based on the activation of light-absorbing photosensitizers (PS) to generate reactive oxygen species, which are toxic to the targeted disease cells. Because most PS are hydrophobic with poor water solubility, it is necessary to encapsulate and solubilize PS in aqueous conditions to improve the photodynamic action for this compound. In this work, gelatin-poly(acrylic acid) nanoparticles (PAA/gelatin nanoparticles) via template polymerization for incorporation aluminum chloride phthalocyanine (ClAlPc) as a model drug for PDT application were developed. Biocompatible core-shell polymeric nanoparticles were fabricated via template polymerization using gelatin and acrylic acid as a reaction system. The nanoparticulate system was studied by scanning electron microscopy, steady-state, and their biological activity was evaluated using in vitro cancer cell lines by classical MTT assay. The obtained nanoparticles had a spherical shape and DLS particle size were determined further and was found to be around 170 nm. The phthalocyanine-loaded-nanoparticles maintained their photophysical behaviour after encapsulation. It is found that ClAlPc can be released from the nanoparticles in a sustained manner with a small initial burst release. In vitro cytotoxicity revealed that ClAlPc-loaded nanoparticles had similar cytotoxicity to free ClAlPc with mouse melanoma cancer cell line (B16-F10). In vitro photoeffects assay indicated that the nanoparticle formulation was superior in anticancer effect to free ClAlPc on mouse melanoma cancer cell line B16-F10. The results indicate that ClAlPc encapsulated in gelatin-poly(acrylic acid) nanoparticles are a successful delivery system for improving photodynamic activity in the target tissue.

Synthesis, photophysical and photobiological characterization of BSA nanoparticles loaded with chloroaluminium phthalocyanine by one-step desolvation technique for photodynamic therapy action.

This work describes the preparation of bovine serum albumin (BSA) nanoparticles by one-step desolvation method using acetone/ethanol as precipitating agent, glutaraldehyde as crosslinking agent, sodium azide as a preservative and water as reaction media for chloroaluminium phthalocyanine (ClAlPc) incorporation for photodynamic therapy action. The characterization of the nanoparticulate system was carried out using steady-state technique, scanning electron microscopy study and their biological activity was evaluated using in vitro macrophages cell lines by classical MTT assay. All the spectroscopy measurements demonstrated good photophysical properties and the in vitro cytotoxicity study showed that the system is not cytotoxic in the darkness, but it exhibits a substantial phototoxicity at 0.90 mol.L-1 of photosensitizer concentration and 10.0 J cm-2 of light. These conditions are sufficient to kill about 90% of the cells. The results allowed us to conclude that ClAlPc-loaded in BSA nanoparticles might have potential application on drug delivery system for PDT protocols.