Control of medium-chain-length PHA properties

本研究致力于制备性能可控的中链长聚羟基烷酸酯(MCL-PHAs)的方法。MCL-PHAs是一种新型的可生物降解弹性体，由细菌从植物油和糖等可再生资源中生产。MCL-PHAs是纸张涂层、生物医学植入物和打印碳粉等应用的理想选择，但由于生产困难，它们无法在商业上获得。我之前的发现基金通过反驳流行的教条解决了大多数问题，从而使发酵过程得到了极大的简化。本项目的目的是进一步改进这一过程，并生产千克数量的新材料，然后可以首次充分表征这些材料。本研究还旨在开发方法来控制它们在水和/或人体中的降解率。我之前的发现资助证明，这些材料可以通过生物活性蛋白与MCL-PHA纳米颗粒的共价连接而具有生物活性。将考察生物活性MCL-PHA中的模型生物活性化合物的缓释情况。MCL-PHAs的有趣的弹性性质归功于结晶交联性。这种材料将通过共价交联产生更坚韧、更有弹性的形式，并对其生物降解性进行评估。这项研究的总体目标是使这类防水可堆肥热弹性体的生产在商业上变得可行，从而为未来以生物炼油为基础的化学工业增加另一组材料。

This research focuses on methods to produce medium-chain-length polyhydroxyalkanoates (MCL-PHAs) with controlled properties. MCL-PHAs are novel biodegradable elastomers produced by bacteria from renewable resources such as plant oils and sugars. MCL-PHAs are ideal for applications such as paper coating, biomedical implants and printing toners but they were not commercially available due to difficulties in their production. My previous Discovery Grant solved most of these problems by disproving prevailing dogma, thus allowing the development of a greatly simplified fermentation process. The present project aims at further improving this process and producing kg quantities of novel materials which can then be adequately characterized for the first time. The present research also aims to develop methods to control the rate of their degradation in water and/or the human body. My previous Discovery Grant demonstrated that these materials could be rendered bioactive by the covalent attachment of bioactive proteins to nanoparticles of MCL-PHA. The slow release of a model bioactive compound from bioactive MCL-PHA will be examined. MCL-PHAs owe their interesting elastomeric properties to crystalline cross-linking. Even tougher, more rubbery, forms of this material will be produced by covalent cross-linking and their biodegradability assessed. The overall objective of this research is to allow production of this class of water-resistant compostable thermoelastomers to become commercially feasible, thus adding another group of materials to the future "biorefinery"-based chemical industry.