低CMC纳米载体PEGMA-b-PLLA-b-PCL的制备及其药物缓释性能

Preparation of low CMC nanocarrier PEGMA-b-PLLA-b-PCL and its drug sustained release performance

摘要:

以ε-己内酯（ε-CL）为疏水原料，聚乙二醇甲醚甲基丙烯酸酯（PEGMA）为亲水原料，通过引入亲疏水性过渡原料L-丙交酯（LLA），利用可逆加成-断裂链转移法（RAFT）制备了超低临界胶束浓度（CMC）的聚乙二醇甲醚甲基丙烯酸酯-聚丙交酯-聚己内酯（PEGMA-b-PLLA-b-PCL）。通过FTIR、1HNMR、GPC、DLS和SEM对聚合物的结构、相对分子质量（简称分子量）及粒径进行测定，用界面张力法测得PEGMA-b-PLLA-b-PCL 胶束溶液的CMC，用溶剂挥发法负载姜黄素（CUR）制备载药胶束溶液，并计算其载药量和包封率，进一步考察载药胶束溶液在不同环境下的释药能力。结果表明，聚合物相对分子质量（简称分子量）为1220~8782，粒径为28~180 nm，且最低CMC为0.62 μg/mL（pH=7.4）。载药胶束的载药量和包封率最高可达12.6%和78 .0% (pH=7.4)，且药物释放可在15 d内完成，在pH=5环境下释放量最高可达45.53%。

Abstract:

Using ε-caprolactone (ε-CL) as hydrophobic material and poly(ethylene glycol) methyl ether methacrylate (PEGMA) as hydrophilic material, L-Lactide (LLA) was introduced as a hydrophilic and hydrophobic transition material, poly(ethylene glycol) methyl ether methacrylate-b-poly(L-lactide)-b-poly(ε-caprolactone)(PEGMA-b-PLLA-b-PCL) was prepared by Reversible Addition-Fragmentation Chain Transfer (RAFT) method with ultra-low critical micellar concentration (CMC). The structure, relative molecular weight (molecular weight) and particle size of the polymer were characterized by FTIR, 1HNMR, GPC, DLS and SEM. CMC was measured by interstitial-tension method, curcumin was loaded by solvent volatilization method, and the drug loading and encapsulation rate of the micelles were calculated by curcumin UV standard curve. Then, the drug release ability of drug-carrying micelles in different environments was further investigated. The results showed that the molecular weight of PEGMA-b-PLLA-b-PCL ranges from 1220 to 8782, the particle size ranges from 28 to 180 nm, and the lowest CMC is 0.62 μg/mL (pH=7.4). The drug loading and encapsulation rate of the micelle were high, reaching 12.6% and 78.0% (pH=7.4), and the drug release could be completed within 15 days. The maximum drug release was 45.53% at pH=5.