Development of exosomes and bioinspired vesicles for drug delivery

It has been already demonstrated that cell membrane-coated biomaterials are endowed with superior biocompatibility, decreased clearance rate from the rethiculoendothelial system, improved colloidal stability and homotypic targeting abilities. In the present research, two different types of cell cultures were employed as cell membranes (CM) source for the preparation of biomimetic nanosystems: glioblastoma primary cells, obtained from patient biopsies, and colorectal cancer cells cultured from a murine cell line. Isolated CM were analysed in terms of retained protein content and the elimination of residual genetic material from parent cells was assessed in this fraction. Glioblastoma or colorectal cancer CM were used to prepare CM-derived vesicles, and BPA-loaded artificial liposomes were developed and characterize for a future functionalization with glioblastoma CM. CM hybridization with synthetic lipids was also carried out with colorectal cancer CM, to achieve hybrid vesicles improving the production yield. CM and lipids were hybridized following two different techniques, namely the co-extrusion or the mixing using a microfluidic device. All the obtained formulations were characterized in terms of physico-chemical and mechanical properties, morphology and process yield; for hybrids, membrane fusion efficiency was also evaluated. The in vitro internalization and homologous selectivity of biomimetic vesicles into parent cells and different cell types were investigated by confocal microscopy and flow cytometry. The obtained results confirmed that pure and stable bio-inspired nanosystems were developed with good production yield both from primary cells and from the immortalized cell line. Moreover, thanks to the cell-derived membranes, their selective cellular uptake sensibly increased in comparison to artificial liposomes, reaching the highest value in homotypic internalization into parent cells.