Abstract
Nanoparticle-based drug delivery system has been intensively studied in recent years. Due to the enhanced permeability and retention (EPR) effect at the tumor region, nanoparticles can accumulate at tumor intrinsically. Additionally, nanoparticles are able to increase the solubility of hydrophobic drug and change the drug release profile depending on the design of the nanoparticle. These characteristics make nanoparticles attractive drug carriers for cancer therapy. However, the extrinsic nanoparticles can be recognized and eliminated by the reticuloendothelial system (RES). In order to prolong the circulation time of nanoparticles, surface modification of polyethylene glycol (PEG) on the nanoparticles can provide a repulsive force against cells resulting in reduced level of the RES recognition. The modification of PEG (PEGylation) also reduces the nanoparticle uptaken by tumor cells. Several nanoparticles with the conjugation of targeting ligands, such as folate, antibodies, peptides, and aptamers, have been developed to enhance the accumulation at tumor site. Recently, cell membrane-coated nanoparticles were developed by coating natural cell membrane on the nanoparticle. The cell membrane-coated nanoparticles exhibit minimum immunogenicity and show a longer circulation time than PEGylated nanoparticles. In this study, we established a monocyte membrane-coated nanoparticle delivery system, coating the cell membrane extracted from tumor-tropic bone marrow-derived monocyte (BMDM) on a biodegradable poly lactic-co-glycolic acid (PLGA) polymeric core. We demonstrate that a reduced engulfment of macrophage in monocyte membrane-coated nanoparticle compared to the bare nanoparticle. At the meantime, the monocyte membrane-coated nanoparticle shows the capability of tumor-tropism. These results indicate that the monocyte membrane-coated nanoparticle has the therapeutic potential in cancer therapy, and it is worthwhile to further investigate on it.