Pharmaceutical and Biological Evaluation of Nano Photosensitizers for Cancer Therapy

This study demonstrated the effects of novel hybrid metal oxide nanoparticles as an effective nano-photosensitizer for the photodynamic therapy against melanoma in vitro and in vivo. A strong synergistic effect was produced by the hybrid NPs and UV-A irradiation. The hybrid nanoparticles modified with folic acid enhanced cellular uptake and exhibited strong anti-tumour activity alone and with UV-A. These hybrid nanoparticles provide us better understanding in designing the semiconductor metal oxides-based nano-photosensitizers for photodynamic therapy

Cytotoxicity of folic acid conjugated hollow silica nanoparticles toward Caco2 and 3T3 cells, with and without encapsulated DOX

© 2016 Elsevier B.V. Hollow silica nanoparticles of two sizes with and without a folic acid targeting ligand were synthesized. Fickian diffusion of the antitumor drug doxorubicin hydrochloride (DOX) was demonstrated by the produced nanoparticles, achieving a cumulative release of 73% and 45% for 215nm and 430nm particles respectively over a period of 500h. The hollow silica nanoparticles presented a time and dose dependent toxicity, selective to human epithelial colorectal adenocarcinoma (Caco2) cells, over mouse embryonic fibroblast (3T3) cells. At 24h Caco2 cell viability was reduced to 66% using pure hollow silica at a concentration of 50µgmL-1, while that of 3T3 cells remained at 94% under the same conditions. The selective cytotoxicity of hollow silica nanoparticles was further enhanced by conjugation of folic acid and incorporation of DOX: at 24h and an equivalent DOX concentration of 0.5µgmL-1, viable Caco2 cells were reduced to 45% while 3T3 cells were reduced to 83%. Interestingly the equivalent dose of free DOX was more toxic to 3T3 than to Caco2 cells, reducing the 3T3 viability to 72% and the Caco2 viability to 80%, which is likely due to the presence of the p-glycoprotein pumps in Caco2 cells. Folic acid conjugation served to enhance the viability of both cell lines in this work. Careful optimization of the folate content should further improve the cell specificity of the hollow silica nanoparticles, thus providing a viable targeting platform for cancer therapy

Enhanced transfection efficacy of polyethylenimine by surface modification with arginine, lysine and leucine

This paper discusses enhanced transfection efficacy of polyethylenimine by surface modification with arginine, lysine and leucine

Enhanced gene expression in tumors after intravenous administration of arginine-, lysine- and leucine-bearing polyethylenimine polyplex

The potential of gene therapy to treat cancer is currently limited by the low expression of therapeutic genes in the tumors. As amino acids are known to have excellent properties in cell penetration and gene expression regulation, we investigated if the conjugation of arginine, lysine and leucine onto the surface of the gene delivery system polyethylenimine could lead to an improved gene expression in tumors. The intravenous administration of arginine-, lysine- and Leucine-bearing polyethylenimine polyplexes led to a significant increase of gene expression in the tumor, with a β-galactosidase expression amount at least 3-fold higher than that obtained after treatment with unmodified polyethylenimine polyplex. The three amino acid-bearing polyethylenimine led to similar levels of gene expression in the tumor. The treatments were well tolerated by the mice. Arginine-, lysine- and leucine-bearing polyethylenimine are therefore highly promising gene delivery systems for cancer therapy