Dopant-Free Hydrogels with Intrinsic Photoluminescence and Biodegradable Properties
Dopant-Free Hydrogels with Intrinsic Photoluminescence and Biodegradable Properties
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DOI：
10.1002/adfm.201802607
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发表时间：
2018-08-22
影响因子：
19
通讯作者：
Xu, Xiaoyang
中科院分区：
文献类型：
--
作者：
Tsou, Yung-Hao;Zhang, Xue-Qing;Xu, Xiaoyang
作为可注射支架和荧光成像探针的光致发光水凝胶在治疗和组织工程方面具有很大的潜力。目前的荧光水凝胶是通过将荧光染料、荧光蛋白、镧系螯合物或量子点偶联或掺杂到聚合物水凝胶基质中制备的。由于与上述掺杂剂相关的光稳定性、致癌性和毒性等缺点，它们的生物医学应用受到严重限制。本文报道了一种由生物相容性聚合物前体交联形成的无掺杂光致发光原位水凝胶的成功开发，该水凝胶可以通过将氨基酸与柠檬酸基聚酯低聚物结合，然后在南极假丝酵母脂肪酶B的催化下通过方便的酯交换反应将多价交联基团功能化来合成。结果表明，新制备的水凝胶具有降解可调、固有光致发光和机械性能，并具有不同分子量右旋糖酐的持续释放。体内研究表明，皮下注射后原位形成的水凝胶具有良好的生物相容性，无需使用任何传统的有机染料，在可见光激发下可发出强烈的荧光。然后通过无创监测注射的水凝胶植入物的荧光强度来描述它们的体内降解概况。
Photoluminescent hydrogels that function as both injectable scaffolds and fluorescent imaging probes hold great potential for therapeutics delivery and tissue engineering. Current fluorescent hydrogels are fabricated by either conjugating or doping a fluorescent dye, fluorescent protein, lanthanide chelate, or quantum dot into polymeric hydrogel matrix. Their biomedical applications are severely limited due to drawbacks such as photostability, carcinogenesis, and toxicity associated with the above-mentioned dopants. Here, a successful development of dopant-free photoluminescent hydrogels in situ formed by crosslinking of biocompatible polymer precursors is reported, which can be synthesized by incorporating an amino acid to a citric acid based polyester oligomer followed by functionalization of multivalent crosslinking group through a convenient transesterification reaction using Candida Antarctica Lipase B as a catalyst. It is demonstrated that the newly developed hydrogels possess tunable degradation, intrinsic photoluminescence, mechanical properties, and exhibit sustained release of various molecular weight dextrans. In vivo study shows that the hydrogels formed in situ following subcutaneous injection exhibit excellent biocompatibility and emit strong fluorescence under visible light excitation without the need of using any traditional organic dyes. Their in vivo degradation profiles are then depicted by noninvasively monitoring fluorescence intensity of the injected hydrogel implants.