Gelatin coatings are effective in increasing the retention of MSCs injected into the heart and minimizing the damage from acute myocardial infarction (AMI), but early studies suffered from low fractions of the MSCs coated with gelatin. Biotinylation of the MSC surface is a critical first step in the gelatin coating process, and in this study, we evaluated the use of biotinylated cholesterol “lipid insertion” anchors as a substitute for the covalent NHS‐biotin anchors to the cell surface. Streptavidin‐eosin molecules, where eosin is our photoinitiator, can then be bound to the cell surface through biotin‐streptavidin affinity. The use of cholesterol anchors increased streptavidin density on the surface of MSCs further driving polymerization and allowing for an increased fraction of MSCs coated with gelatin (83%) when compared to NHS‐biotin (52%). Additionally, the cholesterol anchors increased the uniformity of the coating on the MSC surface and supported greater numbers of coated MSCs even when the streptavidin density was slightly lower than that of an NHS‐biotin anchoring strategy. Critically, this improvement in gelatin coating efficiency did not impact cytokine secretion and other critical MSC functions. Proper selection of the cholesterol anchor and the biotinylation conditions supports cellular function and densities of streptavidin on the MSC surface of up to ~10⁵ streptavidin molecules/μm². In all, these cholesterol anchors offer an effective path towards the formation of conformal coatings on the majority of MSCs to improve the retention of MSCs in the heart following AMI.

中文翻译：

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通过胆固醇插入增加明胶包被的治疗细胞的产量。


明胶涂层可有效增加注射到心脏中的 MSC 的保留并最大限度地减少急性心肌梗死 (AMI) 造成的损害，但早期研究发现明胶涂层的 MSC 比例较低。 MSC 表面的生物素化是明胶涂层过程中关键的第一步，在这项研究中，我们评估了使用生物素化胆固醇“脂质插入”锚作为细胞表面共价 NHS 生物素锚的替代品。链霉亲和素-伊红分子（其中伊红是我们的光引发剂）可以通过生物素-链霉亲和素亲和力结合到细胞表面。与 NHS 生物素 (52%) 相比，胆固醇锚的使用增加了 MSC 表面的链霉亲和素密度，进一步驱动聚合，并增加了明胶包被的 MSC 比例 (83%)。此外，胆固醇锚增加了 MSC 表面涂层的均匀性，并支持更多数量的涂层 MSC，即使链霉亲和素密度略低于 NHS-生物素锚定策略。重要的是，明胶包被效率的提高并没有影响细胞因子的分泌和其他关键的 MSC 功能。正确选择胆固醇锚和生物素化条件可支持细胞功能和 MSC 表面上高达约 10 ⁵链霉亲和素分子/μm ²的链霉亲和素密度。总之，这些胆固醇锚提供了在大多数 MSC 上形成保形涂层的有效途径，以改善 AMI 后 MSC 在心脏中的保留。