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: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=363925
• 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-羟基烷酸酯），PHA，是一类可生物降解的高分子量聚酯，是细菌的碳储备材料。聚（3-羟基丁酸酯）（PHB）由于其立构规整性和高熔点，形成了轮廓清晰的板条状单晶，被用作生物降解结晶塑料的模型。这就是生物技术塑料，它在世界石油供应减少的时候拯救了我们。它的起源是生物质发酵，就像酿造啤酒一样。这家工厂是一家以玉米为原料的生物炼制厂。这一领域的研发重点是对晶体生长和生物降解过程的新理解，这是从使用解聚酶作为物理纹理探针的研究中产生的。提出了一种新的从稀溶液中生长晶体的策略，包括淬火、晶须和自组装。获得的新的聚羟基丁酸形态表明，这种可持续塑料的生物降解是晶体生长过程的逆转。因为PHA聚酯被认为是生物相容的，它们被考虑用于生物医学应用，如骨水泥，缝合线和药物输送。与PHB一样，聚硫酯（PTE）在添加巯基烷基底物的工程化细菌细胞中以颗粒形式积累。与微生物含氧酯相比，其物理性质变化很大。硫-硫相互作用的作用将被研究，以寻求更大的热稳定性的一些PTE的解释。