A. Neamţu 1, O. C. Mungiu 2
1 Asist. Drd. – Disciplina de Biofizică şi Bioinstrumentaţie, Facultatea de Medicină Dentară, Universitatea de Medicină şi Farmacie „Gr. T. Popa”, Iaşi
2 Prof. Dr. – Disciplina de Farmacologie, Toxicologie şi Algeziologie, Facultatea de Medicină, Universitatea de Medicină şi Farmacie „Gr. T. Popa”, Iaşi
Abstract
The central phenomenon which plays a negative role in the therapeutic success of liposomal drug delivery formulations administered i.v. is the opsonization of transporters surface. This interaction reduces the circulation times of liposomes loaded with drugs by promoting their clearance from blood. Although there is a great amount of experimental results regarding the opsonization effect, there is much less understanding of the intimate molecular mechanisms of protein (opsonin) – liposome surface interactions. The aim of this second part of the study is to develop a methodology for the analysis of Sterically Stabilized Liposome (SSL) – opsonin interactions using molecular modeling techniques. We developed, using the previously validated model for liposomes (Neamţu, 2006), a method for predicting the shielding capabilities of SSL liposomes with respect to their physical and chemical surface properties.. Consequently we applied it to three varieties of pegilated liposomes which differ in the surface coverage densities and in the molecular mass of the polymer used. The method proved itself sensible enough to point out significant differences between the liposomes subjected to analysis. Finally, the liposomes with low coverage densities but with high polyethylenglicol molecular mass and especially mixed coverage liposomes proved the best shielding capabilities.