Institute of Biomedical Engineering, 164 College Street, Toronto, ON, M5S 3G9, Canada.
Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON, M5S 3E1, Canada.
Adv Mater. 2022 Aug;34(34):e2202612. doi: 10.1002/adma.202202612. Epub 2022 Jul 24.
With the advent of increasingly complex combination strategies of biologics, independent control over their delivery is the key to their efficacy; however, current approaches are hindered by the limited independent tunability of their release rates. To overcome these limitations, directed evolution is used to engineer highly specific, low affinity affibody binding partners to multiple therapeutic proteins to independently control protein release rates. As a proof-of-concept, specific affibody binding partners for two proteins with broad therapeutic utility: insulin-like growth factor-1 (IGF-1) and pigment epithelium-derived factor (PEDF) are identified. Protein-affibody binding interactions specific to these target proteins with equilibrium dissociation constants (K ) between 10 and 10 m are discovered. The affibodies are covalently bound to the backbone of crosslinked hydrogels using click chemistry, enabling sustained, independent, and simultaneous release of bioactive IGF-1 and PEDF over 7 days. The system is tested with C57BL/6J mice in vivo, and the affibody-controlled release of IGF-1 results in sustained activity when compared to bolus IGF-1 delivery. This work demonstrates a new, broadly applicable approach to tune the release of therapeutic proteins simultaneously and independently and thus the way for precise control over the delivery of multicomponent therapies is paved.
随着越来越复杂的生物组合策略的出现，对它们的传递进行独立控制是其疗效的关键；然而，目前的方法受到其释放速率的独立可调性有限的限制。为了克服这些限制，定向进化被用于工程高度特异性、低亲和力的亲和体结合伴侣，以独立控制多种治疗蛋白的释放速率。作为概念验证，针对两种具有广泛治疗用途的蛋白质：胰岛素样生长因子-1（IGF-1）和色素上皮衍生因子（PEDF），鉴定出了特定的亲和体结合伴侣。发现了与这些靶蛋白具有特异性的亲和体-蛋白相互作用，其平衡解离常数（Kd）在 10 到 10 M 之间。使用点击化学将亲和体共价结合到交联水凝胶的骨架上，从而能够在 7 天内持续、独立和同时释放生物活性的 IGF-1 和 PEDF。该系统在 C57BL/6J 小鼠体内进行了测试，与 IGF-1 的大剂量给药相比，亲和体控制的 IGF-1 释放具有持续的活性。这项工作展示了一种新的、广泛适用的方法，可以同时和独立地调节治疗蛋白的释放，从而为多成分治疗的精确控制铺平了道路。
