Zwitterionic Dendrimer-modified PEG for Protein Conjugation

项目摘要 聚合物-蛋白质缀合物由于其在生物医学领域的重要应用而引起了人们的极大兴趣。 治疗多种疾病。作为具有高加工性的水溶性聚合物，聚（乙二醇）（PEG）具有 已经广泛用于蛋白质缀合，并且超过12种PEG化蛋白质已经商业化用于蛋白质缀合。 临床治疗多种疾病（包括关节炎、癌症、肝炎、痛风等），年经营 数十亿美元的销售。然而，PEG可诱导不利的免疫原性并降低蛋白质的生物活性。 两性离子聚合物（ZP）已经作为PEG在这些方面的改进的替代品出现，并且可能导致 甚至更长的循环时间，但通常线性ZP具有低的可加工性，这阻碍了它们的应用。 两性离子树枝状聚合物（ZD）具有比线性ZPs更好的可加工性，但良好控制的蛋白质 直接通过ZD缀合是不可行的。在这个R21提案中，我们的目标是将ZD与PEG集成， ZD-修饰的PEG（ZD-PEG）作为用于蛋白质缀合的新型共聚物的开发。中央 假设ZD-PEG是PEG的改进替代物，并且ZD-PEG化蛋白质（ZD-PEG-PTEN） 可保留蛋白质生物活性，减轻PEG抗原性，并具有一系列有利的生物医学相关性， 特性.根据多边投资机构的互补专长，提出了以下两个具体目标：1） 开发ZD-PEG和ZD-PEG-PTEN，2）了解ZD-PEG-PTEN的生物医学相关性质。 PTEN。ZD-PEG，其各自具有两性（ZW）官能化的基于聚（酰胺基胺）的ZD单元和PEG 设计了以ω-N-羟基琥珀酰亚胺（NHS）为末端的嵌段。具有不同ZD的ZD-PEG文库 代（G1至G4）、ZW型（羧基甜菜碱、磺基甜菜碱或磷酸胆碱）和PEG长度（5 K和 10 K）将通过制备具有炔焦点官能度的ZD，然后将其偶联来合成。 具有α-叠氮化物的ZD，通过炔-叠氮化物点击化学的ω-NHS PEG。以猪样尿酸酶为模型蛋白， 将通过ω-NHS的酰胺化反应制备具有受控PEG化密度的ZD-PEG-尿酸酶 具有尿酸酶的胺官能团的ZD-PEG末端。全面的分析方法将 用于表征ZD-PEG和ZD-PEG-尿酸酶，以验证其良好控制的结构。系统 将进行ZD-PEG-尿酸酶的性质研究，以深入了解其结构- 财产关系。研究了ZD-PEG改性对复合材料溶解性、抗生物污损性、酶活性的影响 尿酸酶的活性、免疫应答、循环时间、生物分布和毒性将通过以下方式进行研究： 体外和体内研究。具体而言，ZW类型、ZD生成、PEG长度和PEG化密度 将评估这些生物医学相关属性的影响。建议的R21研究不仅承诺 建立了ZD-PEG和ZD-PEG-PTEN的合成方法，但也提供了关键的见解， 结构依赖性生物医学相关性质。这些研究将为今后的研究奠定坚实的基础 开发ZD-PEG-PTEN作为用于许多临床应用的新型治疗剂。

PROJECT SUMMARY Polymer-protein conjugates have attracted significant interest because of their critical biomedical applications in treating many diseases. As a water-soluble polymer with high processability, poly(ethylene glycol) (PEG) has been widely used for protein conjugation, and over a dozen PEGylated proteins have been commercialized for the clinical treatment of various diseases (including arthritis, cancer, hepatitis, and gout, etc.), with an annual sale of multi-billion dollars. However, PEG can induce unfavorable immunogenicity and reduce protein bioactivity. Zwitterionic polymers (ZPs) have emerged as improved alternatives for PEG on these aspects and may lead to even longer circulation time, but typically linear ZPs have low processability, which hinders their applications. Zwitterionic dendrimers (ZDs) have improved processability than linear ZPs, but well-controlled protein conjugation directly by ZDs is not feasible. In this R21 proposal, we aim to integrate ZDs with PEGs for the development of ZD-modified PEGs (ZD-PEGs) as novel copolymers for protein conjugation. The central hypothesis is that ZD-PEGs are improved alternatives of PEGs, and ZD-PEGylated proteins (ZD-PEG-PTENs) can retain protein bioactivity, mitigate PEG antigenicity, and possess a range of favorable biomedical-relevant properties. Based on the complementary expertise of MPIs, the following two specific aims are proposed: 1) to develop ZD-PEGs and ZD-PEG-PTENs, and 2) to understand the biomedical-related properties of ZD-PEG- PTENs. ZD-PEGs each having a zwitterion (ZW)-functionalized poly(amidoamine)-based ZD unit and a PEG block with ω-N-hydroxysuccinimide (NHS) terminal are designed. A library of ZD-PEGs with varied ZD generation (G1 to G4), ZW type (carboxybetaine, sulfobetaine, or phosphorylcholine), and PEG length (5K and 10K) will be synthesized by the preparation of ZDs with an alkyne focal functionality, followed by coupling the ZDs with α-azide,ω-NHS PEGs via alkyne-azide click chemistry. Using porcine-like uricase as a model protein, ZD-PEG-uricases with controlled PEGylation density will be prepared through amidation reactions of ω-NHS terminals of ZD-PEGs with amine functionalities of uricase. Comprehensive analytical approaches will be employed to characterize ZD-PEGs and ZD-PEG-uricase to verify their well-controlled structures. Systematic property studies of ZD-PEG-uricases will be performed to achieve an insightful understanding of their structure- property relationships. The effects of ZD-PEG modification on the solubility, anti-biofouling property, enzyme activity, immune response, circulation time, biodistribution, and toxicity of uricase will be investigated through both in vitro and in vivo studies. Specifically, how ZW type, ZD generation, PEG length, and PEGylation density affect these biomedical-related properties will be assessed. The proposed R21 studies promise to not only establish the synthetic methodology for ZD-PEGs and ZD-PEG-PTENs, but also provide critical insights into their structure-dependent biomedical-relevant properties. These studies will lay a solid foundation for the further development of ZD-PEG-PTENs as novel therapeutics for many clinical applications.