Vesna Milacic Vesna Milacic, Schwendeman Steven P
Pharm Res. 2014 Feb;31(2):436-48. doi: 10.1007/s11095-013-1173-6.
We evaluated the controlled release of lysozyme from various poly(D,L-lactic-co-glycolic acid) (PLGA) 50/50-polyethylene glycol (PEG) block copolymers relative to PLGA 50/50.
Lysozyme was encapsulated in cylindrical implants (0.8 mm diameter) by a solvent extrusion method. Release studies were conducted in phosphate buffered saline +0.02% Tween 80 (PBST) at 37°C. Lysozyme activity was measured by a fluorescence-based assay. Implant erosion was evaluated by kinetics of polymer molecular weight decline, water uptake, and mass loss.
Lysozyme release from an AB15 di-block copolymer (15% 5 kDa PEG, PLGA 28 kDa) was very fast, whereas an AB10 di-block copolymer (with 10% 5 kDa PEG, PLGA 45 kDa) and ABA10 tri-block copolymer (with 10% 6 kDa PEG, PLGA 27 kDa) showed release profiles similar to PLGA. We achieved continuous lysozyme release for up to 4 weeks from AB10 and ABA10 by lysozyme co-encapsulation with the pore-forming and acid-neutralizing MgCO3, and from AB15 by co-encapsulation of MgCO3 and blending AB15 with PLGA. Lysozyme activity was mostly recovered during 4 weeks.
These block co-polymers may have utility either alone or as PLGA blends for the controlled release of proteins.
我们评估了相对于聚（D，L-乳酸-乙醇酸共聚物）（PLGA）50/50，溶菌酶从各种PLGA 50/50-聚乙二醇（PEG）嵌段共聚物中的控释情况。
通过溶剂挤出法将溶菌酶封装在圆柱形植入物（直径0.8毫米）中。在37°C的磷酸盐缓冲盐水+0.02%吐温80（PBST）中进行释放研究。通过基于荧光的测定法测量溶菌酶活性。通过聚合物分子量下降、吸水率和质量损失的动力学来评估植入物的侵蚀情况。
从AB15二嵌段共聚物（15% 5 kDa PEG，PLGA 28 kDa）中释放溶菌酶非常快，而AB10二嵌段共聚物（含10% 5 kDa PEG，PLGA 45 kDa）和ABA10三嵌段共聚物（含10% 6 kDa PEG，PLGA 27 kDa）显示出与PLGA相似的释放曲线。通过将溶菌酶与成孔和中和酸的MgCO3共封装，我们从AB10和ABA10中实现了长达4周的持续溶菌酶释放，通过MgCO3共封装并将AB15与PLGA混合，从AB15中实现了持续释放。溶菌酶活性在4周内大部分得以恢复。
这些嵌段共聚物单独使用或作为PLGA共混物用于蛋白质的控释可能具有实用性。
