New aspects of polyhydroxyalkanoates: chain folding and precursor self assembly; polythioesters

聚羟基脂肪酸酯的新方面：链折叠和前体自组装；

• 批准号: 12378-2006
• 负责人: Marchessault, Robert
• 金额: $ 2.19万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2006
• 资助国家: 加拿大
• 起止时间: 2006-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=336240
• 关键词: New; aspects; polyhydroxyalkanoates; chain; folding

Poly(3-hydroxyalkanoates), PHA, are a family of high molecular weight biodegradable polyesters which are carbon reserve material for bacteria. Because of their stereoregularity and high melting point, poly(3-hydroxybutyrate), PHB, form well-defined lath-shape single crystals which are used as model biodegradable crystalline plastics. This is the biotech plastic that has come to the rescue as world oil supplies dwindle. Its origin is biomass fermentation, like making beer. The factory is a biorefinery with corn as the raw material. R & D in this field focuses on a new understanding of the crystal growth and biodegradation process which is generated from studies using depolymerase enzymes as physical texture probes. A new crystal growth strategy from dilute PHB solution involving quenching, whiskers and self-assembly has been proposed. The new PHB morphologies obtained suggest that biodegradation of this sustainable plastic is a reversal of the crystal growth process. Because PHA polyesters are considered biocompatible, they are being considered for biomedical applications such as bone cement, sutures and drug delivery. Like PHB, polythioesters (PTEs) accumulate as granules in engineered bacterial cells with the addition of mercaptoalkyl substrates. The physical properties vary substantially in comparison with microbial oxyesters. The role of sulfur-sulfur interactions will be studied to seek an explanation for greater thermal stability of some PTEs.

聚（3-羟基链烷酸酯）（PHA）是一类高分子量可生物降解聚酯，是细菌的碳储备材料。由于其立构规整性和高熔点，聚（3-羟基丁酸酯）（PHB）可形成轮廓分明的板条状单晶，用作可生物降解结晶塑料的模型。随着世界石油供应的减少，这种生物技术塑料发挥了作用。它的起源是生物质发酵，就像酿造啤酒一样。该工厂是以玉米为原料的生物精炼厂。该领域的研发重点是对晶体生长和生物降解过程的新理解，这是通过使用解聚酶作为物理结构探针的研究产生的。提出了一种新的稀 PHB 溶液晶体生长策略，涉及淬火、晶须和自组装。获得的新 PHB 形态表明，这种可持续塑料的生物降解是晶体生长过程的逆转。由于 PHA 聚酯被认为具有生物相容性，因此它们被考虑用于生物医学应用，例如骨水泥、缝合线和药物输送。与 PHB 一样，聚硫酯 (PTE) 在添加了巯基烷基底物的工程细菌细胞中以颗粒形式积累。与微生物氧化酯相比，其物理性质差异很大。我们将研究硫-硫相互作用的作用，以寻求一些 PTE 更高热稳定性的解释。