Microporous annealed particle (MAP) scaffolds consist of a slurry of hydrogel microspheres that undergo annealing to form a solid scaffold. MAP scaffolds have contained functional groups with dual abilities to participate in Michael-type addition (gelation) and radical polymerization (photoannealing). Functional groups with efficient Michael-type additions react with thiols and amines under physiological conditions, limiting usage for therapeutic delivery. We present a heterofunctional maleimide/methacrylamide 4-arm PEG macromer (MethMal) engineered for selective photopolymerization compatible with multiple polymer backbones. Rheology using two classes of photoinitiators demonstrates advantageous photopolymerization capabilities. Functional assays show benefits for therapeutic delivery and 3D printing without impacting cell viability.

中文翻译：

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微孔退火粒子 (MAP) 支架的选择性和改进的光退火

微孔退火粒子 (MAP) 支架由水凝胶微球浆液组成，这些微球体经过退火形成固体支架。MAP 支架包含具有参与迈克尔型加成（凝胶化）和自由基聚合（光退火）的双重能力的官能团。具有有效迈克尔型加成的官能团在生理条件下与硫醇和胺反应，限制了治疗递送的使用。我们提出了一种异功能马来酰亚胺/甲基丙烯酰胺 4 臂 PEG 大分子单体 (MethMal)，用于与多种聚合物主链兼容的选择性光聚合。使用两类光引发剂的流变学证明了有利的光聚合能力。功能分析显示了在不影响细胞活力的情况下治疗递送和 3D 打印的好处。