Design and Fabrication of Nanostructured "Smart" Hydrogels from Biopolymer Nanoparticle Building Blocks

天然聚合物的生物基产品可以在环境中完全降解，作为传统合成聚合物的可持续功能性替代品或添加剂，正引起人们的极大兴趣。水凝胶，水膨胀聚合物网络，是生物基产品的理想目标材料，因为许多生物聚合物是水溶性的，而且水凝胶的许多最终应用（即生物医学和环境）需要有效和安全的降解才能发挥适当的功能。在水凝胶方面，淀粉是一种特别有吸引力的生物基材料，因为它无毒、生物相容性好、可生物降解，而且价格便宜。然而，天然淀粉含有晶体结构域，这使得它很难进行化学修饰，从而导致化学不均匀的聚合物，这使得设计定义明确的功能水凝胶具有挑战性。我们的合作伙伴EcoSynthetix已经通过创建定义明确的生物聚合物纳米颗粒解决了这一挑战，这些纳米颗粒易于修改，并且可以在商业规模上生产。我们建议将这些生物聚合物纳米颗粒作为构建块，用于制造具有各种独特内部结构的功能水凝胶，使用纳米颗粒作为填料来降低昂贵的功能水凝胶的成本，或者（在生物聚合物的酶降解之后）用于生成定义良好的孔隙网络的模板。重点将放在开发含有重要生物聚合物成分的“智能”、对环境敏感的水凝胶上，从而在保留此类材料功能的同时降低成本。靶向水凝胶组合物将应用于开发药物输送、组织工程、农业、环境修复和工业催化等新材料，特别是在每种应用中利用生物聚合物纳米颗粒的独特性质。这项研究的成功完成将产生新的、可持续的、功能性的水凝胶材料，具有改善医疗保健、工业制造和环境的潜力，为加拿大带来重大的经济和社会效益。

Bio-based products from natural polymers that can be fully degraded in the environment are attracting tremendous interest as sustainable yet functional replacements or additives for conventional synthetic polymers. Hydrogels, water-swollen polymer networks, are ideal target materials for bio-based products given that many biological polymers are water-soluble and many of the ultimate applications of hydrogels (i.e. biomedical and environmental) require effective and safe degradation for proper function. In the context of hydrogels, starch is a particularly attractive bio-based building block considering that it is non-toxic, biocompatible, biodegradable, and inexpensive. However, native starch contains crystalline domains that make it hard to chemically modify, leading to chemically heterogeneous polymers that make the design of well-defined functional hydrogels challenging. Our partner, EcoSynthetix, has addressed this challenge by creating well-defined biopolymer nanoparticles that are easily modifiable and produced on a commercial scale. We propose applying these biopolymer nanoparticles as building blocks for the fabrication of functional hydrogels with a variety of unique internal structures, using the nanoparticles as both fillers to reduce the cost of expensive functional hydrogels or (following enzymatic degradation of the biopolymer) templates for the generation of well-defined pore networks. A particular emphasis will be placed on developing "smart", environmentally-responsive hydrogels containing a significant biopolymer component, thus reducing the cost while preserving the functionality of such materials. Targeted hydrogel compositions will be applied to develop new materials for drug delivery, tissue engineering, agriculture, environmental remediation, and industrial catalysis, specifically exploiting the unique properties of the biopolymer nanoparticles in each application. Successful completion of the proposed research will result in new, sustainable, and functional hydrogel materials with potential to improve healthcare, industrial manufacturing, and the environment, offering significant economic and societal benefits to Canada.