NANO-SCALED BIOPOLYMERS FROM BIODEGRADABLE MATERIALS
(0) Cancer is the most serious disease that threatens human lives. In China, now there are about 4 million cancer patients, increasing by 1.5 to 2 million per year. Most of the cancers have high recurrence to nearly 100% in a few months, and more than 30% of the cancer patients (1.5 million) died every year in China. Until now, surgery operation is still the effective method for cancer therapy with the aid of radiotherapy and anti-cancer drugs. However, there are still many problems in the application of anticancer drugs. For example, they have quite limited and low curative effect; sometimes, they need to be injected in high dose which often brings serious side effect; they have the fast circulation clearance; and some of them do not have suitable drug forms for clinical applications. For example, paclitaxel is a broad spectrum anticancer drug commonly used in clinical trial. However, it is very expensive and water insoluble. The solvent used for paclitaxel (PEO-castor oil/ethanol) often brings heavy allergy reaction. In our research groups, we cultivated a new drug form which using amphiphilic copolymers binding with paclitaxel covalently. the initial rush out of the loaded drugs which often happens in the encapsulate type. And the ester bong between paclitaxel and PLA could be easily hydrolyzed for steady drug release. Several types of the amphiphilic copolymers were synthesized for different types of drug loading. And the drug loading degree could be easily controlled. All the copolymers could form nano particles by selfassembly and nearly no initial rush out of the paclitaxel. The drug could be release steadily in a longer time than usual clinical injection form. The cytotoxicity of the paclitaxel conjugated copolymers (we call it Plataxel) was examined using human liver cancer H7402cells, Hela cells and C6 glioma cells. The carrier materials express a high compatibility without paclitaxel loaded. The Plataxel indicated good inhibition ratio to all the cancer cells. We also found that the distribution of the Plataxel in rat organs varied from the different size of the nano particles, indicating the enhanced permeation and retention effect (EPR effect) in some degree, which could be a useful tool for passive targeting. Not only drugs, but also proteins can be conjugated with the amphiphilic copolymers to act as a new kind of bioactive materials. In our research, we also bind hemoglobin (protein in red blood cells) with the amphiphilic copolymers micelles using the same concept as described above. The system also has the oxygen binding ability while changing the oxygen partial pressure. By simply adjust the salt concentration, pH and viscosity, this Hb-PEG-PLA nano-particles would have great possibility to be used as a new type of red blood cell substitute oxygen binding ability while changing the oxygen partial pressure. By simply adjust the salt concentration, pH and viscosity, this Hb-PEG-PLA nano-particles would have great possibility to be used as a new type of red blood cell substitute.
Yubin HUANG Xiabin JING Xuesi CHEN
Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P.R.China
国际会议
PP’2010，Jinan International Symposium on Polymer Physics(2010济南国际高分子物理学术研讨会)
济南
英文
126-127
2010-06-06（万方平台首次上网日期，不代表论文的发表时间）