Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON M5S 3E5, Canada.
Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
Biomacromolecules. 2020 Jun 8;21(6):2421-2431. doi: 10.1021/acs.biomac.0c00357. Epub 2020 Apr 22.
A hydrogel that can deliver both proteins and cells enables the local microenvironment of transplanted cells to be manipulated with a single injection. Toward this goal, we designed a hydrogel suitable for the co-delivery of neural stem cells and chondroitinase ABC (ChABC), a potent enzyme that degrades the glial scar that forms after central nervous system (CNS) injury. We leveraged the inverse electron-demand Diels-Alder reaction between norbornene and methylphenyltetrazine to form rapidly gelling (<15 min) crosslinked methylcellulose (MC) hydrogels at physiological temperature and pH, with Young's modulus similar to that of brain tissue (1-3 kPa), and degradable, disulfide-containing crosslinkers. To achieve tunable, affinity-controlled release of a ChABC-Src homology 3 (SH3) fusion protein, we immobilized norbornene-functionalized SH3-binding peptides onto MC-methylphenyltetrazine and observed release of bioactive ChABC-SH3 over 4 days. We confirmed cytocompatibility by evaluating neural progenitor cell survival and proliferation. The combined encapsulation of neural stem cells and chondroitinase ABC from one hydrogel lays the framework for future in vivo studies to treat CNS injuries.
一种可同时递送蛋白质和细胞的水凝胶，可通过单次注射来操纵移植细胞的局部微环境。为此，我们设计了一种适合神经干细胞和软骨素酶 ABC（ChABC）共递送的水凝胶，ChABC 是一种有效的酶，可降解中枢神经系统（CNS）损伤后形成的神经胶质瘢痕。我们利用降冰片烯和甲基苯四嗪之间的逆电子需求 Diels-Alder 反应，在生理温度和 pH 值下形成快速凝胶化（<15 分钟）的交联甲基纤维素（MC）水凝胶，杨氏模量与脑组织相似（1-3 kPa），并且具有可降解的含二硫键交联剂。为了实现 ChABC-Src 同源 3（SH3）融合蛋白的可调、亲和控制释放，我们将降冰片烯功能化的 SH3 结合肽固定在 MC-甲基苯四嗪上，并观察到生物活性 ChABC-SH3 在 4 天内释放。我们通过评估神经祖细胞的存活和增殖来确认细胞相容性。一种水凝胶中同时包封神经干细胞和软骨素酶 ABC 为未来治疗 CNS 损伤的体内研究奠定了基础。
