Novel approaches for drug delivery systems in nanomedicine: effects of particle design and shape

Abstract

The identification of novel drug candidates for the treatment of diseases like cancer, infectious diseases, or allergies (especially asthma) assigns new tasks for pharmaceutical technology. With respect to drug delivery several problems occur such as low solubility and hence low bioavailability or restriction to inconvenient routes of administration. Nanotechnological approaches promise to circumvent some of these problems, therefore being well suited for future applications as nanomedicines. Furthermore, efficient and sufficient loading is a critical issue that is approached through mesoporous particles and/or through nonspherical particles both offering larger volumes and surfaces. Special interest is laid on the effect of shape of particulate materials on the body and related physiological mechanisms. The modified response of biological systems on different shapes opens a new dimension to adjust particle system interaction. Finally, the biological response to these systems will determine the fate with respect to their therapeutic value. Therefore, the interaction pattern between nonspherical particulate materials and biological systems as well as the production processes are highlighted.

Design Advances in Particulate Systems for Biomedical Applications

“…Generally, smaller particles are internalized by endocytosis and larger ones (>500 nm) by phagocytosis, but the later pathway only occurs in specialized cells, such as macrophages. [ 47 ] However, exceptions have been verifi ed: for example endothelial cells have shown the capacity to internalize particles as large as 5 µm via endocytosis. [ 73 ] The intracellular transport to reach the targeted organelle is also dependent on the size of the particles.…”

Macrophage uptake of cylindrical microparticles investigated with correlative microscopy

“…InteracƟons with biological systems differ for non-spherical parƟcles, opening up new opƟons for the design of drug delivery systems [1][2][3].…”

“…This physiologically highly relevant task, essenƟal for homeostasis of healthy Ɵssue and clearance, was found to be strongly influenced by the shape of the object [1,2].…”

“…As a consequence, non-spherical parƟcles such as cylindrical parƟcles have the potenƟal to control clearance processes, a core prerequisite for a sustained release system for therapeuƟcs [2,4].…”

“…Cylinder-like parƟcles can be prepared following various techniques [2]. Tailor-made truly cylindrical parƟcles require boƩom-up formaƟon within a template, dictaƟng the geometry.…”