| Popis: |
In the last decades, nanomedicine – the application of nanotechnology to medicine – has opened up an entirely new horizon of possibilities and applications, in particular for drug delivery and diagnostic. Indeed, a wide range of nanocarrier have been designed and realized. However, more recently researcher focused on the development of “multifunctional” platforms, i.e. nano-vectors able to simultaneously or sequentially perform several functionalities – enzymatic catalysis, controlled degradation, controlled drug release and sensing. In this context polyelectrolyte multilayer (PEM) capsules fabricated via the Layer-by-Layer (LbL) technique have emerged as very attractive tool for the assembly of multifunctional carrier systems, because of its ideal features like simplicity, versatility, and nanoscale control. The final aim of this research activity concerns the realization of completely biocompatible and biodegradable nanocarriers with diverse functionalities and purposes. The greater ambition, in particular, is the realization of nanometric sized drug vehicles entirely derived from natural materials but holding the features needed for the drug delivery. Starting from an inner oil-core carrier – with tunable sizes ranging from 80 to 200 nm, built up with natural materials like soybean oil and egg lecithin and able to encapsulate hydrophobic drugs or contrasting agents - oil-core polyelectrolytes-shells nanocarriers have been realized. As for the liquid core, natural materials have been selected for the realization of the shell, and, in particular, polysaccharides. More in detail, polysaccharides used as coating have been opportunely modified in order to add desired functionalities to the final nano-vectors. As matter of the fact, it was demonstrated how the thiolation of the nanocapsules’ surfaces, together with the appropriate choice of the materials, sizes and formulation, can positively effect on the oral delivery of an unstable nutraceutical, i.e. curcumin. Moreover, the modification of natural polyelectrolytes with thiol and olefin moieties allowed to covalently cross link the layers by applying a photo activated reaction, thiol-ene ‘click’ reaction: it was demonstrated that such strategy bring out to a final nano-system with enhanced biostability. Lastly, an in situ modification of heparin with an aminosilane allowed to apply a modified Stöber sol-gel method for the realization of a high versatile multilayered nanocarrier system featuring a hybrid polymer/silica-shell. All the designed and realized nanocapsules did not show any cytotoxic effect, so resulting completely biocompatible and, therefore, of interest for the nanomedicine fields. |
