Novel oppositely charged polyphosphazene polyelectrolytes containing grafted poly(ethylene glycol) (PEG) chains were synthesized as modular components for the assembly of biodegradable PEGylated protein delivery vehicles. These macromolecular counterparts, which contained either carboxylic acid or tertiary amino groups, were then formulated at near physiological conditions into supramolecular assemblies of nanoscale level, below 100 nm. Nanocomplexes with electroneutral surface charge, as assessed by zeta potential measurements, were stable in aqueous solutions, which suggests their compact polyelectrolyte complex “core”–hydrophilic PEG “shell” structure. Investigation of PEGylated polyphosphazene nanocomplexes as agents for noncovalent PEGylation of the therapeutic protein l-asparaginase (L-ASP) in vitro demonstrated their ability to dramatically reduce protein antigenicity, as measured by antibody binding using enzyme linked immunosorbent assay (ELISA). Encapsulation in nanocomplexes did not affect enzymatic activity of L-ASP, but improved its thermal stability and proteolytic resistance. Gel permeation chromatography (GPC) experiments revealed that all synthesized polyphosphazenes exhibited composition controlled hydrolytic degradability in aqueous solutions at neutral pH and showed greater stability at lower temperatures. Overall, novel hydrolytically degradable polyphosphazene polyelectrolytes capable of spontaneous self-assembly into PEGylated nanoparticulates in aqueous solutions can potentially enable a simple and effective approach to modifying therapeutic proteins without the need for their covalent modification.

中文翻译：

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可水解降解的聚乙二醇化聚电解质纳米复合物，用于蛋白质递送

合成了含有接枝聚乙二醇（PEG）链的新型带相反电荷的聚磷腈聚电解质，作为组装可生物降解的聚乙二醇化蛋白递送载体的模块组件。然后将包含羧酸或叔氨基的这些大分子对应物在接近生理条件的条件下制成低于100 nm的纳米级超分子组装体。通过zeta电位测量评估的具有电子中性表面电荷的纳米复合物在水溶液中是稳定的，这表明它们具有紧凑的聚电解质复合物“核心”-亲水性PEG“壳”结构。聚乙二醇化聚磷腈纳米复合物作为治疗性蛋白1非共价聚乙二醇化试剂的研究使用酶联免疫吸附测定法（ELISA）通过抗体结合测定，体外天冬酰胺酶（L-ASP）证明了其显着降低蛋白质抗原性的能力。纳米复合物中的包封不影响L-ASP的酶活性，但改善了其热稳定性和耐蛋白水解性。凝胶渗透色谱（GPC）实验表明，所有合成的聚磷腈在中性pH下在水溶液中均表现出组成受控的水解降解性，并在较低温度下显示出更大的稳定性。全面的，