Poly(D,L-lactide-co-glycolide) dispersions containing pluronics: from particle preparation to temperature-triggered aggregation.
Poly(D,L-lactide-co-glycolide) dispersions containing pluronics: from particle preparation to temperature-triggered aggregation.
复制标题
DOI：
10.1021/la800869u
复制
发表时间：
2008-06
期刊：
影响因子：
--
通讯作者：
Michael Fraylich;Wenxin Wang;K. Shakesheff;C. Alexander;B. Saunders
中科院分区：
文献类型：
--
作者：
Michael Fraylich;Wenxin Wang;K. Shakesheff;C. Alexander;B. Saunders
本论文主要研究了聚（D，L-丙交酯-乙交酯）（PLGA）分散体的制备机理、性能和温度引发的聚集。通过在含有Pluronic L 62（EO（6）PO（30）EO（6））或F127 NF（EO（101）PO（56）EO（101））的水溶液中界面沉积来制备分散体，其中EO和PO分别是环氧乙烷和环氧丙烷。为了比较，还在不添加Pluronic的情况下制备PLGA分散体。使用SEM、光子相关光谱和电泳迁移率测量对PLGA颗粒进行表征。发现流体动力学直径（d）随着有机溶剂相中使用的PLGA浓度（C PLGA（o））而增加。d的值与C（PLGA）（0）成比例（1/3）。加入0.04 M NaNO（3）后，d值增加，这证明了静电相互作用在颗粒形成过程中的重要性。电泳迁移率测量作为pH的函数进行，数据用于估计PLGA颗粒上的普朗尼克层厚度。在Pluronic F127 NF存在下制备的PLGA颗粒的层厚度最大。含有Pluronic L 62的PLGA分散体在0.15 M NaNO（3）存在下表现出温度触发的聚集。发现分散体聚集的临界温度（T（crit））与母体Pluronic L 62溶液的浊点温度（T（cp））相当。建立了在生理离子强度和pH条件下PLGA颗粒/Pluronic L 62分散体在体温下实现温度触发聚集的条件。研究的PLGA/Pluronic L 62混合物可能具有用作可注射的生物可降解植入物用于控释应用的潜力。
In this work the preparation mechanism, properties and temperature-triggered aggregation of poly(D, L-lactide- co-glycolide) (PLGA) dispersions are investigated. The dispersions were prepared by interfacial deposition in aqueous solution containing Pluronic L62 (EO(6)PO(30)EO(6)) or F127NF (EO(101)PO(56)EO(101)), where EO and PO are ethylene oxide and propylene oxide, respectively. PLGA dispersions were also prepared in the absence of added Pluronic for comparison. The PLGA particles were characterized using SEM, photon correlation spectroscopy and electrophoretic mobility measurements. It was found that the hydrodynamic diameter (d) increased with PLGA concentration used in the organic solvent phase ( C PLGA(o) ). The value for d was proportional to C(PLGA)(o) (1/3). The value for d increased upon addition of 0.04 M NaNO(3) which demonstrated the importance of electrostatic interactions during particle formation. Electrophoretic mobility measurements were conducted as a function of pH and the data used to estimate the Pluronic layer thicknesses on the PLGA particles. The layer thickness was greatest for the PLGA particles prepared in the presence of Pluronic F127NF. PLGA dispersions containing Pluronic L62 exhibited temperature-triggered aggregation in the presence of 0.15 M NaNO(3). It was found that the critical temperature for dispersion aggregation (T(crit)) was comparable to the cloud point temperature ( T(cp)) for the parent Pluronic L62 solution. Conditions were established for achieving temperature-triggered aggregation at body temperature for PLGA particle/Pluronic L62 dispersions under physiological ionic strength and pH conditions. The PLGA/Pluronic L62 mixtures studied may have potential for use as injectable biodegradable implants for controlled release applications.