Mechanically adaptive materials that soften upon exposure to physiological conditions are useful for biomedical applications, notably as substrates for implantable neural electrodes. So far, device fabrication efforts have largely relied on shaping such devices by laser cutting, but this process makes it difficult to produce complex electrode architectures and leads to ill-defined surface chemistries. Here, we report mechanically adaptive, physiologically responsive polymers that can be photopolymerized and thus patterned via soft lithography and photolithography. The adaptive polymer networks produced exhibit, in optimized compositions, a ca. 500-fold decrease of their storage modulus when exposed to simulated physiological conditions, for example, from 2.5 GPa to 5 MPa. This effect is caused by modest swelling (30% w/w), which in turn leads to plasticization so that the polymer network's glass transition temperature is reduced from 145 to 25 °C. The polymer networks can further be rendered pH-responsive by the incorporation of methacrylic acid. The dual stimuli-responsive materials thus made show promise as coatings or substrates for drug delivery devices.

中文翻译：

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通过光聚合制得的高度交联，具有生理响应性，机械适应性的聚合物网络。

在暴露于生理条件后变软的机械适应性材料可用于生物医学应用，尤其是作为可植入神经电极的基底。迄今为止，设备制造的努力主要依靠通过激光切割对这种设备进行整形，但是这种工艺使其难以生产复杂的电极架构，并导致表面化学性质不明确。在这里，我们报告机械适应性，生理响应的聚合物，可以进行光聚合，并通过软光刻和光刻形成图案。产生的适应性聚合物网络在优化的组成中显示出约1。当暴露于模拟生理条件（例如，从2.5 GPa至5 MPa）时，其储能模量降低500倍。这种效果是由适度的溶胀（30％w / w）引起的，进而导致增塑，因此聚合物网络的玻璃化转变温度从145降低到25°C。通过引入甲基丙烯酸，可进一步使聚合物网络具有pH响应性。如此制成的双重刺激响应性材料有望作为药物输送装置的涂层或基材。