Label-Free Imaging of Composite Hyaluronic Acid Hydrogels in Regenerative Medicine

再生医学中复合透明质酸水凝胶的无标记成像

• 批准号: 9389085
• 负责人: Jeff W. Bulte
• 金额: $ 38.15万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9389085
• 关键词: Affect; Amyotrophic Lateral Sclerosis; Animals; Antigens; Behavioral; Biocompatible Materials; Biological Markers; Biological Preservation; Blood Vessels; Cell Survival; Cell Transplantation; Cell Transplants; Cells; Cervical; Chemicals; Color; Cues; Diffusion; Dimensions; Disease Outcome; Disease model; Encapsulated; Engraftment; Environment; Frequencies; Gel; Gelatin; Gold; Green Fluorescent Proteins; Hand; Human; Hyaluronic Acid; Hydration status; Hydrogels; Hypoxia; Image; Imaging Techniques; Immune response; Implant; In Vitro; Injectable; Injection of therapeutic agent; Kinetics; Label; Longevity; Luciferases; Magnetic Resonance Imaging; Mechanical Stress; Mechanics; Modification; Molecular Structure; Monitor; Mus; Near-infrared optical imaging; Nutrient; Nutritional; Optical reporter; Polymers; Primary Lateral Sclerosis; Property; Regenerative Medicine; Reporter Genes; Reporting; Signal Transduction; Stem cell transplant; Stem cells; Study models; Sulfhydryl Compounds; Surrogate Markers; Suspensions; Techniques; Testing; Time; Tissues; Transgenic Animals; Transgenic Organisms; Transplantation; Trauma; Treatment Efficacy; Validation; Water; adaptive immune response; biomaterial compatibility; chemical property; crosslink; imaging approach; imaging modality; imaging study; implantation; improved; in vivo; mechanical properties; mouse model; nerve stem cell; novel; optical imaging; physical property; precursor cell; response; scaffold; tissue culture

Hydrogel scaffolds are increasingly being used as tissue-mimicking materials and as vehicles to improve transplanted stem cell retention and survival. We have recently developed a new chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) method that is able to probe the in vivo stability and gelatin decomposition of implanted composite hyaluronic acid (HA) hydrogels in a “label-free” fashion. Compared to naked cells, we found that transplanted neural stem cells showed improved survival when hydrogel scaffolding was applied. A major question that remains is the optimal mechanical properties of the hydrogel, and how this relates to cell survival. At the one hand, for initial structural support, the gels should not decompose too fast, but at the other hand they should at some point decompose to allow transplanted cells to grow out and integrate with the surrounding host tissue. Our aim is to synthesize a range of composite near- infrared (NIR)-HA hydrogels with different compositions and stabilities, to image their stability properties in vivo, and to correlate the CEST/NIR optical imaging findings with cell survival as assessed using bioluminescent imaging (BLI) as conventional readout. Using supercharged green fluorescent protein (sGFP) as a new CEST MRI bimodal reporter gene, we will also investigate whether or not CEST MRI is able to probe in vivo cell survival simultaneously. We have chosen to apply this approach to transplantation of glial-restricted precursor cells (GRPs) in a transgenic amyotropic lateral sclerosis (ALS) mouse model, as we have found that transplanted naked cells without hydrogel scaffolding survive poorly in the hostile ALS tissue environment.

水凝胶支架越来越多地被用作组织模拟材料和改善组织的载体 移植干细胞的保留和存活。我们最近开发了一种新的化学交换 饱和转移（CEST）磁共振成像（MRI）方法能够探测体内稳定性 以“无标记”方式植入复合透明质酸（HA）水凝胶的明胶分解。 与裸细胞相比，我们发现移植的神经干细胞在以下情况下表现出更高的存活率： 应用水凝胶支架。仍然存在的一个主要问题是该材料的最佳机械性能 水凝胶，以及它与细胞存活的关系。一方面，对于初始结构支撑，凝胶不应该 分解太快，但另一方面它们应该在某个时刻分解以允许移植的细胞 生长并与周围的宿主组织融合。我们的目标是合成一系列复合材料 具有不同成分和稳定性的红外 (NIR)-HA 水凝胶，以对其稳定性进行成像 体内，并将 CEST/NIR 光学成像结果与使用评估的细胞存活率相关联 生物发光成像（BLI）作为传统读数。使用增压绿色荧光蛋白 (sGFP) 作为新的CEST MRI双峰报告基因，我们还将研究CEST MRI是否能够探测 体内细胞同时存活。我们选择将这种方法应用于胶质限制性细胞的移植 转基因肌萎缩侧索硬化症（ALS）小鼠模型中的前体细胞（GRP），我们发现 没有水凝胶支架的移植裸细胞在恶劣的 ALS 组织环境中存活率很低。