Chemo-Mechanical and Chemo-Structural pH-Feedback Mechanisms to Program Transient and Autonomous Self-Assembling Systems

在前一个资助阶段的基础上，我们构思了在均相溶液中具有瞬时pH状态的pH反馈系统，并将它们耦合到不同范围的pH可切换自组装，以在自主系统中对它们进行自我调节寿命的编程，这项提议针对下一步在主动反馈机制方面以及在设计自主的、化学燃料的、非平衡的软物质和自组装系统方面。因此，这一建议超越了均相溶液中的化学反馈，旨在开发和定量地理解可概括的、自我调节的、耦合的Chemo-X pH反馈机制：(I)化学-机械pH反馈系统是基于pH调节酶(具有pH依赖的活性分布)，嵌入具有pH依赖的门控效应(底物扩散)的pH响应型核壳胶体中，以自我调节酶的活性。(2)化学结构的pH反馈系统是以嵌入在共组装的核壳胶体中的pH调节酶级联为基础的，具有依赖于pH的共组装行为，其中形成的共组装编码其自身的破坏。这将产生新的系统特征，包括(A)具有受控滞后时间和寿命的瞬时pH曲线，(B)可以通过向嵌入的酶提供真正的休眠区来重新激活的pH曲线，以及(C)通过受控同步滞后效应、反应/扩散时间尺度、由化学机械反馈施加的时间控制的自门效应以及时间协调的自我调节化学结构反馈的振荡系统。这些使能概念允许向自主动态材料系统、产生自我调节和时间编程记忆功能的方向发展。我们的目标是研究新型自擦除二肽水凝胶的这种行为，并展示它们在微流体电路中用于流体引导的用途。具体目的是找到在Sol-Gel-Sol系统中实现滞后和寿命的正交规划的途径，并利用凝胶发生之前的受控滞后时间来允许前体受控地分布到分支通道网络中，以模拟复杂血管网络中的血流阻塞。

Building on the preceding funding phase, where we conceived pH-feedback systems with transient pH-states in homogeneous solution, and coupled them to a diverse range of pH-switchable self-assemblies to program them with self-regulating lifetimes in autonomous systems, this proposal targets the next steps in terms of active feedback mechanisms and in the design of autonomous, chemically fuelled, non-equilibrium soft matter and self-assembly systems. This proposal hence goes beyond chemical feedback in homogeneous solution and aims to develop and quantitatively understand generalizable, self-regulating, coupled chemo-X pH-feedback mechanisms:(i) chemo-mechanical pH-feedback systems are based on pH-modulating enzymes (with pH-dependent activity profile) as embedded in pH-responsive core-shell colloids with pH-dependent gating effects (substrat diffusion) to self-regulate the enzymatic activity. (ii) chemo-structural pH-feedback system are based on pH-modulating enzyme cascades as embedded in co-assembling core-shell colloids, featuring pH-dependent co-assembly behavior, and in which a formed co-assembly encodes its own destruction. This will give rise to new systems features, including (a) transient pH-profiles with controlled lag times and lifetimes, (b) pH-profiles that can be reactivated by providing truly dormant areas to the embedded enzymes, and (c) oscillating systems by controlled synchronization of hysteresis effects, reaction/diffusion timescales, and temporally controlled self-gating effects imposed by chemo-mechanical feedback as well as temporally orchestrated self-regulating chemo-structural feedback.These enabling concepts allow advancements toward autonomously dynamic material systems, spawning self-regulation and time-programmed memory functions. We aim to investigate this behavior for new types of self-erasing dipeptide hydrogels and showcase their use for fluidic guidance in microfluidic circuits. Particular aims are to find pathways towards an orthogonal programming of lag and life times in sol-gel-sol systems, and to exploit controlled lag times before gelation occurs to allow controlled distribution of precursors into branching channel networks to mimic blood flow blocking in complex vascular networks.