Reported by: KE Xuan
Translated by: DENG Ke
Edited by: LU Haiyan
Updated by: 2012-8-27
HIT Professor CAI Wei’s program A Study on Long-circulating Magnetic Iron Oxide Nanoparticles (MION) in Bionic Modification, supported by Heilongjiang Outstanding Youth Science Fund, passed inspection. 15 papers from the program have been published by SCI and 2 national invention patents have been authorized.
MION is provided with fine magnetic performance and biocompatibility. It’s expected to widely apply to highly sensitive magnetic resonance imaging of human body, targeting drug, hyperthermia and gene delivery. However, the common problem of MION employed to human body is that fast assimilation in reticuloendothelial system leads to too short circulation time in vivo. It fails to maintain effective blood concentration and circulation time to conduct image diagnosis and drug delivery for the organization outside reticuloendothelial system. This is the major obstacle for its medical application.
Red blood cell can survive for 120 days in blood circulation without being killed by macrophage. The cell structure gives experts beneficial inspiration. With the idea of bionics design and the method of atom transfer radical polymerization, Professor CAI created phosphorylcholine polymer on the surface of MION in situ so that the structure of cell membrane was simulated. Under physiological conditions,phosphorylcholine polymer has high matching flexibility with biomolecule (e.g. plasma molecule) and can effectively restrain the absorption of plasma proteins without any rejection. It plays a decisive role on preventing MION from being killed by reticuloendothelial system. The result shows that the MION biomimetically modified by phosphorylcholine polymer has excellent colloid stability, blood compatibility and extended circulation time in vivo. It’s expected to make a breakthrough for early diagnosis and treatment of cancer and other serious illness.
