Interfacial Activity of PEG-modified Proteins with Application to Sustained Release

PEG 修饰蛋白质的界面活性及其在缓释中的应用

• 批准号: 0755284
• 负责人: Robert Tilton
• 金额: $ 29.36万
• 依托单位: Carnegie-Mellon University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0755284&HistoricalAwards=false
• 关键词: Interfacial; Activity; PEG; modified; Proteins

CBET-0755284TiltonRecently published work indicates that covalent conjugation of proteins with poly(ethylene glycol), i.e., "protein PEGylation", significantly increases both the total amount of encapsulated protein released from poly(lactide-co-glycolide) (PLG) microsphere depots and the fractional retention of biological activity after sustained release. This research is based on the hypothesis that these beneficial effects are due mainly to the effects of the PEG grafts on protein adsorption and that PEGylation controls the adsorption affinity, reversibility, severity of surface induced conformational changes and aggregation, at both the oil/water and solid/water interfaces that are relevant to microsphere depot manufacture and sustained drug release application.PEGylation is already a proven technology for increasing in vivo circulation times and efficacy of many injected protein therapeutics. The proposed research concerns a new application of protein PEGylation to minimize protein bioactivity loss during sustained release from biodegradable depots. While protein release from PLG depots is a complex process involving many coupled phenomena, protein adsorption to interfaces is a well known source of lost protein activity during release. This research will determine whether and how PEGylation moderates the deleterious effects of adsorption on protein release, and will indicate just which aspects of the complex adsorption processes are most important to control in future formulation efforts. By minimizing one of the major obstacles to widespread use of PLG depots for sustained protein release, this research will represent important progress toward the ultimate goal of complete, sustained release of fully active protein drugs. To that end, complementary spectroscopic and optical techniques will be used to reveal the effects of PEGylation on protein adsorption to the oil/water interfaces that are generated during the commonly used double emulsion microsphere manufacturing process and the solid PLG/water interfaces that are generated during release from the degrading microspheres. The effects of PEG grafts on protein vulnerability to surface-induced secondary and tertiary conformational change and aggregation, as well as the extent and reversibility of adsorption will be emphasized. Molecular level studies of adsorption phenomena will be conducted in parallel with in vitro release studies using the same materials in order to correlate release behaviors with the underlying interfacial phenomena.By modulating protein/surface interactions, the well-known beneficial effects of PEGylation on protein therapeutic efficacy will be amplified for conjugates administered via sustained release depots. PLG microspheres, originally envisioned as implantable protein delivery depots, have been far more successful for non-protein pharmaceuticals than for proteins largely because protein conformation and solubility are highly sensitive to local environment, particularly to the damaging effects of protein-surface interactions. To achieve the full promise of sustained protein release from biodegradable depots, surface-induced loss of bioavailability must be minimized. The proposed project will provide research training for two Ph.D. students. Undergraduate students will participate in the research during each of the three years as well. The project also provides broader undergraduate educational benefits through the development of hands-on exercises to complement lectures on biomaterials and drug delivery in the first year undergraduate Introduction to Biomedical Engineering course. An outreach program will benefit middle school and high school science education in the Pittsburgh Public Schools district. One middle school or high school science teacher will be hosted by the PI and Co-PI during a summer break to develop appropriate versions of the hands-on exercises, plus associated teaching materials, that they will incorporate into their own classrooms. Products of this activity will be broadly disseminated by co-authoring a paper to submit to a leading journal for science teachers.

CBET-0755284Tilton最近发表的工作表明，蛋白质与聚乙二醇的共价缀合，即“蛋白质聚乙二醇化”，显着增加了从聚丙交酯乙交酯 (PLG) 微球储库中释放的封装蛋白质的总量和持续释放后生物活性的保留分数。 这项研究基于以下假设：这些有益效果主要是由于 PEG 接枝对蛋白质吸附的影响，并且聚乙二醇化控制着油/水和与微球储库制造和持续药物释放应用相关的固体/水界面。聚乙二醇化已经是一项经过验证的技术，可增加体内循环时间和许多注射蛋白质疗法的功效。拟议的研究涉及蛋白质聚乙二醇化的新应用，以最大限度地减少从可生物降解的储库持续释放过程中蛋白质生物活性的损失。虽然蛋白质从 PLG 库中释放是一个复杂的过程，涉及许多耦合现象，但蛋白质吸附到界面是释放过程中蛋白质活性损失的一个众所周知的来源。这项研究将确定聚乙二醇化是否以及如何减轻吸附对蛋白质释放的有害影响，并将表明复杂吸附过程的哪些方面对于未来制剂工作中控制最重要。 通过最大限度地减少广泛使用 PLG 储库进行蛋白质持续释放的主要障碍之一，这项研究将代表朝着完全、持续释放完全活性蛋白质药物的最终目标取得的重要进展。 为此，将使用互补的光谱和光学技术来揭示聚乙二醇化对蛋白质吸附到常用双乳液微球制造过程中产生的油/水界面以及在过程中产生的固体PLG/水界面的影响。从降解微球中释放。 将强调 PEG 接枝对蛋白质对表面诱导的二级和三级构象变化和聚集的脆弱性的影响，以及吸附的程度和可逆性。 吸附现象的分子水平研究将与使用相同材料的体外释放研究并行进行，以便将释放行为与潜在的界面现象相关联。通过调节蛋白质/表面相互作用，聚乙二醇化对蛋白质治疗的众所周知的有益作用通过缓释储库施用的缀合物的功效将被放大。 PLG 微球最初被设想为可植入的蛋白质递送库，在非蛋白质药物方面比在蛋白质方面更成功，这主要是因为蛋白质构象和溶解度对局部环境高度敏感，特别是对蛋白质表面相互作用的破坏性影响。 为了充分实现从可生物降解的储存库中持续释放蛋白质的承诺，必须最大限度地减少表面引起的生物利用度损失。 拟议的项目将为两名博士提供研究培训。学生。本科生也将在三年中每年参与这项研究。 该项目还通过开发实践练习来补充本科生生物医学工程导论课程第一年的生物材料和药物输送讲座，从而提供更广泛的本科生教育效益。一项外展计划将使匹兹堡公立学区的初中和高中科学教育受益。一名初中或高中科学教师将在暑假期间由 PI 和 Co-PI 主持，开发合适版本的实践练习以及相关教材，并将其纳入自己的课堂。这项活动的产品将通过共同撰写一篇论文提交给科学教师的领先期刊来广泛传播。