Bioimaging Research, Sanofi Global R&D, 49 New York Avenue, Framingham, MA 01701, USA.
Diabetes Research, Sanofi Global R&D, 153 Second Avenue, Waltham, MA 02451, USA.
Biomaterials. 2018 Sep;178:326-338. doi: 10.1016/j.biomaterials.2018.05.037. Epub 2018 May 23.
Hyaluronic acid (HA) hydrogels have found a wide range of applications in biomedicine: regenerative medicine to drug delivery applications. In vivo quantitative assessment of these hydrogels using magnetic resonance imaging (MRI) provides an effective, accurate, safe, and non-invasive translational approach to assess the biodegradability of HA hydrogels. Chemical exchange saturation transfer (CEST) is an MRI contrast enhancement technique that overcomes the concentration limitation of other techniques like magnetic resonance spectroscopy (MRS) by detecting metabolites at up to two orders of magnitude or higher. In this study, HA hydrogels were synthesized based on different crosslinking agents and assessed using CEST MRI to investigate the in vivo degradation profiles of these gels in a mouse subcutaneous injection model over a three-month period. Nature of crosslinking agents was found to influence their degradation profiles. Since CEST MRI provides a unique chemical signature to visualize HA hydrogels, our studies proved that this technique could be used as a guide in the hydrogel optimization process for drug delivery and regenerative medicine applications.
透明质酸（HA）水凝胶在生物医学领域有广泛的应用：从再生医学到药物输送应用。使用磁共振成像（MRI）对这些水凝胶进行体内定量评估，为评估 HA 水凝胶的生物降解性提供了一种有效、准确、安全和非侵入性的转化方法。化学交换饱和转移（CEST）是一种 MRI 对比增强技术，通过检测代谢物，可克服磁共振波谱（MRS）等其他技术的浓度限制，检测灵敏度高达两个数量级或更高。在这项研究中，根据不同的交联剂合成了 HA 水凝胶，并使用 CEST MRI 进行评估，以研究这些水凝胶在三个月的小鼠皮下注射模型中的体内降解情况。交联剂的性质被发现会影响它们的降解情况。由于 CEST MRI 提供了一种独特的化学特征来可视化 HA 水凝胶，我们的研究证明，该技术可用于药物输送和再生医学应用的水凝胶优化过程中的指导。
