Sculpted Amphiphilic Liposomal Particles for Modifiable Medicinal Applications

Dipak   K.   Sarker

Abstract

The surface coverage and leaflet anchoring of polymeric surfactants and other amphiphiles can be used to provide a particle with extensive modifiable ‘stealth’ properties. This is not a new conceptual tool but one which has significant strategic advantage and recent proven clinical application in a “drug-delivery-package”. This has been established and widely reported as a fundamental basis for optimal utility with long-circulation drug nanoparticles. The indirect “disguising” of the medicinal payload presents itself as a form of “pro-drug” system that can be used to extend circulation lifetime and that is key to a number of essential current and future risk-bearing therapies. Appropriate particle sizing and leaflet chemical structuring, in terms of number of strata, complexity, extent and curvature can also be used as the means to “drug anchoring” for the incorporation of “hydrophobic” drugs. Actives that are chemo- or solvent labile can also be housed, often routinely, within the inner-protected chamber of such capsular systems. This has frequently formed the basis of a number of recently developed commercial preparations that are used ubiquitously in now standard chemotherapy. Additionally, the use of complementary and non-complementary phospholipid or other vesicle ingredient mixtures below, at or above the lipid “gel transition” temperature or within a “glassy” crystalline packing configuration can provide a particle of varied physical and mechanical composition that provides a possible route to the production of fusogenic nano-drugs or control over the drug release profile. Successive layering of the nanoparticle can in principle provide the means to a step-wise or timed release of the particle contents and one that can be adapted to the site of intended use.

Keywords: Leaflet, encapsulation, toxicity, targeting, phospholipid, polymeric coating, physicochemical properties