树枝化聚合物构筑受限微环境

受限微环境对生命体内生物大分子的功能具有重要影响。仿生构筑受限微环境，实现对分子性质和功能有效控制具有重要的学术价值，并为材料设计提供新思路。本项目拟基于与生物大分子类似单分子纳米尺度的烷氧醚类树枝化聚合物，结合其独特柱状形貌及优异温敏特性，构筑不同尺度的物理化学受限微环境，实现对客体的有效包络、屏蔽及迁移控制。包括：（1）通过调节树形烷氧醚结构基元（代数、支化臂数、端基），精准调控聚合物单分子尺度、链刚柔性、空间位阻、链堆砌密度（crowding）以及亲疏水性等，构筑不同分子尺度受限微环境；（2）通过制备树形聚合物微纳米球，构筑由聚合物、微球几何形状和尺度协同效应的微纳米尺度受限微环境。重点研究这些受限微环境及温度诱导的微环境可逆调控对不同尺寸客体分子性质和功能的影响。该项目的成功实施，不仅为构筑不同尺度受限微环境提供崭新路径，同时为开发新型生物医药载体以及微器件等功能材料提供全新策略。

The confined micro-environment in the biological system plays an important role in mediating functions of biomacromolecules. Constructing confined micro-environments in a bio-mimic way to facilitate control over molecular properties and functions, can provide new strategies for developing functional materials. In this project, we aim to construct confined micro-environment in different length-scales by using thermoresponsive oligoethylene glycol (OEG)-based dendronized polymers, which possess similar molecular size to biomacromolecules and cylindrical morphology. These dendronized polymer-based microenvironments could promote the encapsulation, shielding and controlled transfer of guest molecules. Firstly, dendronized polymers with varied OEG dendritic structures (generations, degree of branches, end groups) will be prepared. The resulted polymers with different properties including size, chain stiffness, steric hindrance, hydrophilicity and selective interactions, can form micro-environment with varied physicochemical properties that are accurately defined on the molecular level. Then, polymeric microgels will be prepared based on these dendronized polymers, which can form enhanced confined micro-environment combining the synergetic effects between polymer properties and microgel geometry. The influence of these temperature-controlled confined micro-environments on the properties and functions of the molecules (dyes, nucleic acids, proteins, etc.) will be thoroughly investigated. We hope the success of this project will not only provide a novel platform for the construction of man-made confined micro-environment, but also foster new routes for developing function materials including biomedical carriers and micro-devices.