The stability and immunogenicity of a protein antigen encapsulated in biodegradable microparticles based on blends of lactide polymers and polyethylene glycol
The stability and immunogenicity of a protein antigen encapsulated in biodegradable microparticles based on blends of lactide polymers and polyethylene glycol
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DOI：
10.1016/s0264-410x(98)00229-1
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发表时间：
1999-02-12
期刊：
影响因子：
5.5
通讯作者：
Davis, SS
中科院分区：
文献类型：
--
作者：
Lavelle, EC;Yeh, MK;Davis, SS
采用油包水法制备了聚乙二醇（PEG）与聚乳酸（PLA）均聚物或聚乳酸-乙交酯共聚物（PLG）共混物的蛋白质微粒。通过SDS-PAGE分析分别使用PEG和50：50 PLG、75：25 PLG和PLA制备的与微粒结合的卵清蛋白（OVA）的稳定性，并在37 ℃下在PBS中孵育长达1个月后通过扫描光密度法定量。所有3种制剂均检测到OVA的片段化和聚集。这两个过程的程度与所使用的丙交酯聚合物的降解速率相关，并且以PLA < 75：25 PLC < 50：50 PLG的顺序降低。PLG/PEG微粒的广泛降解也在4周内发生，而PLA/PEG共混物的使用导致稳定的微粒形态和大大减少的相关蛋白质的片段化和聚集。在单次皮下免疫后，与PLA/PEG颗粒相关的OVA引起高水平的特异性血清IgG抗体。注射与75：25 PLG/PEG微粒结合的OVA导致非常低水平的特异性抗体。50：50 PLG/PEG制剂诱导了更高的反应，但该组中存在非常大的动物间差异。所有3种制剂引起的抗体水平显著高于单次注射可溶性OVA引起的抗体水平。抗原特异性IgG 1和IgG 2a抗体亚型水平的分析也揭示了PLA/PEG微粒作为佐剂系统的更大功效。PLA/PEG微粒的使用显示出改善的蛋白质负载和递送能力，同时保持相关蛋白质的高水平稳定性。这些结果表明微囊化抗原的稳定性与皮下免疫后免疫应答的强度之间存在强相关性。(C)1999 Elsevier Science Ltd.保留所有权利。
Protein-loaded microparticles were produced from blends of poly(ethylene glycol) (PEG) with poly(L-lactide) (PLA) homopolymer or poly(DL-lactide co-glycolide) copolymers (PLG) using a water-in oil-in oil method. The stability of ovalbumin (OVA) associated with microparticles prepared using PEG and 50:50 PLG, 75:25 PLG and PLA, respectively, was analysed by SDS-PAGE and quantified by scanning densitometry following incubation in PBS at 37 degrees C for up to 1 month. Fragmentation and aggregation of OVA was detected with all 3 formulations. The extent of both processes correlated with the degradation rate of the lactide polymer used and decreased in the order PLA < 75:25 PLC < 50:50 PLG. Extensive degradation of the PLG/PEG microparticles also occurred over 4 weeks whereas the use of PLA/PEG blends resulted in a stable microparticle morphology and much reduced fragmentation and aggregation of the associated protein. Following a single sub-cutaneous immunisation, high levels of specific serum IgG antibody were elicited by OVA associated with the PLA/PEG particles. Injection of OVA associated with the 75:25 PLG/PEG microparticles resulted in very low levels of specific antibody. A higher response was induced by the 50:50 PLG/PEG formulation but there was very large inter-animal variation in this group. Antibody levels elicited by all 3 formulations were significantly higher than those elicited by a single injection of soluble OVA. Analysis of antigen specific IgG1 and IgG2a antibody subtype levels also revealed the greater efficacy of the PLA/PEG microparticles as an adjuvant system. The use of PLA/PEG microparticles shows improved protein loading and delivery capacity while maintaining a high level of stability of the associated protein. These results indicate a strong correlation between the stability of microencapsulated antigen and the magnitude of the immune response following sub-cutaneous immunisation. (C) 1999 Elsevier Science Ltd. All rights reserved.