Tumor microenvironment-mimicking macrophage nanovesicles as a targeted therapy platform for colorectal cancer.

Macrophages are a pivotal immune cell population in the tumor microenvironment of colorectal cancer (CRC). Differently-polarized macrophages could be exploited to yield naturally-tailored biomimetic nanoparticles for CRC targeting. Here, membrane proteins were isolated from the THP-1 cell line, and anti-tumor macrophages (M1) were obtained from differentiation of THP-1. Membrane proteins were isolated from THP-1 and M1 and used to produce lipid nanovesicles (LNVs; T-LNVs and M1-LNVs) by microfluidic process, which were loaded with doxorubicin (DOXO). The DOXO loaded T-LNVs and M1-LNVs showed similar size (120-145 nm), PDI (0.11-0.28), zeta potential (-15 to -30 mV) and drug loading efficiency (65-75 %). Mass-spectrometry confirmed the presence of the membrane proteins in the LNVs. The abundance of proteins related to stealth properties, cancer targeting, endothelial adhesion and immune-related markers was significantly different in T-LNVs and M1-LNVs. Cell culture studies showed that M1-LNVs possessed higher cancer cell targeting, uptake and cytotoxicity compared to T-LNVs. In vivo studies performed with zebrafish embryos showed that M1-LNVs yielded higher cancer cell targeting and cytotoxicity while systemic cytotoxicity was lower compared to free DOXO. These findings confirm the potentiality and versatility of M1-LNVs for cancer treatment, which could be exploited as new avenue of nanoparticles-based therapies for precision medicine.