Novel nanostructural photosensitizers for photodynamic therapy: in vitro studies.

Abstract

Photosensitizing properties of 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin (p-THPP) functionalized by covalent attachment of one chain of poly(ethylene glycol) (PEG) with a molecular weight of 350, 2000, or 5000 Da (p-THPP-PEG(350), p-THPP-PEG(2000), p-THPP-PEG(5000)) were studied in vitro. Dark and photo cytotoxicity of these photosensitizers delivered in solution or embedded in liposomes were evaluated on two cell lines: a human colorectal carcinoma cell line (HCT 116) and a prostate cancer cell line (DU 145), and compared with these treated with free p-THPP. The attachment of PEG chains results in the pronounced reduction of the dark cytotoxicity of the parent porphyrin. Cell viability tests have demonstrated that the phototoxicity of pegylated porphyrins is dependent on the length of PEG chain and p-THPP-PEG(2000) exhibited the highest photodynamic efficacy for both cell lines. The encapsulation into liposomes did not improve the PDT effect. However, the liposomal formulation of p-THPP-PEG(2000) showed a greater tendency to induce apoptosis in both cell lines than the parent or pegylated porphyrin delivered in solution. The colocalization of p-THPP, p-THPP-PEG(2000) and p-THPP-PEG(2000) enclosed in liposomes with fluorescent markers for lysosomes, mitochondria, endoplasmatic reticulum (ER) and Golgi apparatus (GA) was determined in the HCT 116 line. The p-THPP exhibited ubiquitous intracellular distribution with a preference for membranes: mitochondria, ER, GA, lysosomes and plasma membrane. Fluorescence of p-THPP-PEG(2000) was observed within the cytoplasm, with a stronger signal detected in membranous organelle: mitochondria, ER, GA and lysosomes. In contrast, p-THPP-PEG(2000) delivered in liposomes gave a distinct lysosomal pattern of localization.

• Authors: Kinga Nawalany, Aleksandra Rusin, Mariusz Kepczynski, Piotr Filipczak, Marta Kumorek, Bartłomiej Kozik, Hana Weitman, Benjamin Ehrenberg, Zdzisław Krawczyk, Maria Nowakowska
• Journal: International journal of pharmaceutics (Int J Pharm) Vol. 430 Issue 1-2 Pg. 129-40 (Jul 01 2012) ISSN: 1873-3476 [Electronic] Netherlands
• PMID: 22525077 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2012 Elsevier B.V. All rights reserved.

Chemical References

• Liposomes
• Photosensitizing Agents
• Porphyrins
• Polyethylene Glycols
• 5,10,15,20-tetra(4-hydroxyphenyl)porphyrin

Topics

• Apoptosis (drug effects)
• Biological Transport
• Cell Survival (drug effects)
• Chemistry, Pharmaceutical
• Colorectal Neoplasms (metabolism, pathology)
• Flow Cytometry
• HCT116 Cells
• Humans
• Kinetics
• Liposomes
• Male
• Microscopy, Confocal
• Molecular Weight
• Nanomedicine
• Nanoparticles
• Organelles (metabolism)
• Photochemotherapy (methods)
• Photosensitizing Agents (chemistry, metabolism)
• Polyethylene Glycols (chemistry)
• Porphyrins (chemistry, metabolism)
• Prostatic Neoplasms (metabolism, pathology)