Chen Minna H, Wang Leo L, Chung Jennifer J, Kim Young-Hun, Atluri Pavan, Burdick Jason A
Department of Bioengineering and Division of Cardiovascular Surgery, Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
ACS Biomater Sci Eng. 2017 Dec 11;3(12):3146-3160. doi: 10.1021/acsbiomaterials.7b00734. Epub 2017 Nov 7.
Injectable hydrogels have gained popularity as a vehicle for the delivery of cells, growth factors, and other molecules to localize and improve their retention at the injection site, as well as for the mechanical bulking of tissues. However, there are many factors, such as viscosity, storage and loss moduli, and injection force, to consider when evaluating hydrogels for such applications. There are now numerous tools that can be used to quantitatively assess these factors, including for shear-thinning hydrogels because their properties change under mechanical load. Here, we describe relevant rheological tests and ways to measure injection force using a force sensor or a mechanical testing machine toward the evaluation of injectable hydrogels. Injectable, shear-thinning hydrogels can be used in a variety of clinical applications, and as an example we focus on methods for injection into the heart, where an understanding of injection properties and mechanical forces is imperative for consistent hydrogel delivery and retention. We discuss methods for delivery of hydrogels to mouse, rat, and pig hearts in models of myocardial infarction, and compare methods of tissue postprocessing for hydrogel preservation. Our intent is that the methods described herein can be helpful in the design and assessment of shear-thinning hydrogels for widespread biomedical applications.
可注射水凝胶作为一种载体，已广泛应用于细胞、生长因子及其他分子的递送，以实现这些物质在注射部位的定位并提高其滞留率，同时也用于组织的机械填充。然而，在评估用于此类应用的水凝胶时，有许多因素需要考虑，如粘度、储能模量和损耗模量以及注射力等。目前有许多工具可用于定量评估这些因素，包括用于剪切变稀水凝胶，因为它们的性质在机械负载下会发生变化。在此，我们描述了相关的流变学测试以及使用力传感器或机械测试机测量注射力的方法，以用于可注射水凝胶的评估。可注射的剪切变稀水凝胶可用于多种临床应用，例如，我们重点介绍了向心脏注射的方法，在这种情况下，了解注射特性和机械力对于水凝胶的一致递送和滞留至关重要。我们讨论了在心肌梗死模型中将水凝胶递送至小鼠、大鼠和猪心脏的方法，并比较了用于水凝胶保存的组织后处理方法。我们的目的是，本文所述方法有助于设计和评估用于广泛生物医学应用的剪切变稀水凝胶。
