Dhingra Shaifali, Gaur Vidit, Bhattacharya Jayanta, Saha Sampa
Department of Materials Science and Engineering, Indian Institute of Technology Delhi, India.
Centre for Biomedical Engineering, Indian Institute of Technology Delhi, India.
J Mater Chem B. 2022 Dec 22;11(1):83-98. doi: 10.1039/d2tb01477g.
In view of intrinsic challenges encountered in surface patterning on actual biomaterials such as the ones based on biodegradable polymers, we have demonstrated an innovative strategy to create micro-patterns on the surface of tartaric acid based aliphatic polyester P (poly(hexamethylene 2,3--isoprpylidentartarate)) without significant loss of its molecular weight. Around 10 wt% PAG (photoacid generator, 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine) was purposefully encapsulated in a polyester matrix comprising of P and PLA (polylactide) at a ratio of 5 : 95. With the help of a photomask, selective areas of the matrix were exposed to UV radiation at 395 nm for 25 min to trigger the acid release from PAG entrapped unmasked areas for generating hydroxyl functionality that was later converted to an ATRP (atom transfer radical polymerization) initiating moiety on the irradiated domain of P. In subsequent steps, spatio-selective surface modification by surface initiated ATRP was carried out to generate an alternate pattern of polyPEGMA (poly(ethylene glycol)methyl ether methacrylate) and polyDMAPS (poly(3-dimethyl-(methacryloyloxyethyl)ammonium propane sulfonate)) brushes on the matrix. The patterned surface modified with dual brushes was found to be antifouling in nature (rejection of >97% of proteins). Strikingly, an alternate pattern of live bacterial cells ( and ) was evident and a relatively high population of bacteria was found on the polyPEGMA brush modified domain. However, a complete reverse pattern was visible in the case of L929 mouse fibroblast cells, , cells were found to predominantly adhere to and proliferate on the zwitterionic brush modified surface. An attempt was made to discuss a plausible mechanism of selective cell adhesion on the zwitterionic brush domain. This novel strategy employed on the biodegradable polymer surface provides an easy and straightforward way to micro-pattern various cells, bacteria, on biodegradable substrates which hold great potential to function as biochips, diagnostics, bacteria/cell microarrays,
鉴于在基于可生物降解聚合物等实际生物材料上进行表面图案化时遇到的内在挑战，我们展示了一种创新策略，可在基于酒石酸的脂肪族聚酯P（聚（六亚甲基2,3 - 异丙叉酒石酸酯））表面创建微图案，而其分子量不会有显著损失。约10 wt%的光酸发生器（PAG，2 - (4 - 甲氧基苯乙烯基)-4,6 - 双（三氯甲基）-1,3,5 - 三嗪）被有意封装在由P和聚丙交酯（PLA）按5∶95比例组成的聚酯基质中。借助光掩膜，基质的选择性区域在395 nm下暴露于紫外线辐射25分钟，以触发被困在未掩膜区域的PAG释放酸，从而产生羟基官能团，该官能团随后在P的辐照区域转化为原子转移自由基聚合（ATRP）引发部分。在后续步骤中，通过表面引发的ATRP进行空间选择性表面修饰，以在基质上生成聚甲基丙烯酸乙二醇酯（聚（乙二醇）甲基醚甲基丙烯酸酯）和聚3 - 二甲基 - （甲基丙烯酰氧基乙基）铵丙烷磺酸盐（聚（3 - 二甲基 - （甲基丙烯酰氧基乙基）铵丙烷磺酸盐））刷的交替图案。发现用双刷修饰的图案化表面本质上具有抗污性（蛋白质排斥率>97%）。引人注目的是，活细菌细胞（和）的交替图案很明显，并且在聚甲基丙烯酸乙二醇酯刷修饰区域发现了相对大量的细菌。然而，对于L929小鼠成纤维细胞，情况则完全相反，发现细胞主要在两性离子刷修饰的表面上粘附和增殖。我们尝试讨论两性离子刷区域上选择性细胞粘附的合理机制。这种应用于可生物降解聚合物表面的新策略提供了一种简单直接的方法，可在可生物降解基板上对各种细胞、细菌等进行微图案化，这些基板具有作为生物芯片、诊断、细菌/细胞微阵列的巨大潜力。
