Juang Jyuhn-Huarng, Lin Hsiu-Chao, Chen Chen-Yi, Kao Chen-Wei, Chen Chen-Ling, Wu Shu-Ting, Lin Sung-Han, Shen Chia-Rui, Wang Jiun-Jie, Tsai Zei-Tsan, Chu I-Ming
Division of Endocrinology and Metabolism, Department of Internal Medicine and Center for Tissue Engineering, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan.
Department of Medicine, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan.
Polymers (Basel). 2021 Mar 13;13(6):885. doi: 10.3390/polym13060885.
Recently, we demonstrated the feasibility of subcutaneous transplantation of MIN6 cells embedded in a scaffold with poly(ethylene glycol) methyl ether (mPEG)-poly(Ala) hydrogels. In this study, we further tracked these grafts using magnetic resonance (MR) and bioluminescence imaging. After being incubated overnight with chitosan-coated superparamagnetic iron oxide (CSPIO) nanoparticles and then mixed with mPEG-poly(Ala) hydrogels, MIN6 cells appeared as dark spots on MR scans. For in vivo experiments, we transfected MIN6 cells with luciferase and/or incubated them overnight with CSPIO overnight; 5 × 10 MIN6 cells embedded in mPEG-poly(Ala) hydrogels were transplanted into the subcutaneous space of each nude mouse. The graft of CSPIO-labeled MIN6 cells was visualized as a distinct hypointense area on MR images located at the implantation site before day 21. However, this area became hyperintense on MR scans for up to 64 days. In addition, positive bioluminescence images were also observed for up to 64 days after transplantation. The histology of removed grafts showed positive insulin and iron staining. These results indicate mPEG-poly(Ala) is a suitable scaffold for β-cell encapsulation and transplantation. Moreover, MR and bioluminescence imaging are useful noninvasive tools for detecting and monitoring mPEG-poly(Ala) hydrogel-embedded MIN6 cells at a subcutaneous site.
最近，我们证明了将MIN6细胞嵌入聚（乙二醇）甲醚（mPEG）-聚（丙氨酸）水凝胶支架中进行皮下移植的可行性。在本研究中，我们进一步使用磁共振（MR）和生物发光成像对这些移植物进行追踪。在用壳聚糖包被的超顺磁性氧化铁（CSPIO）纳米颗粒孵育过夜后，将MIN6细胞与mPEG-聚（丙氨酸）水凝胶混合，MIN6细胞在MR扫描中表现为黑点。对于体内实验，我们用荧光素酶转染MIN6细胞和/或使其与CSPIO孵育过夜；将5×10个嵌入mPEG-聚（丙氨酸）水凝胶的MIN6细胞移植到每只裸鼠的皮下空间。在第21天之前，CSPIO标记的MIN6细胞移植物在MR图像上显示为植入部位的一个明显的低信号区。然而，在长达64天的MR扫描中，该区域变为高信号。此外，移植后长达64天也观察到了阳性生物发光图像。取出的移植物的组织学检查显示胰岛素和铁染色呈阳性。这些结果表明mPEG-聚（丙氨酸）是用于β细胞包封和移植的合适支架。此外，MR和生物发光成像对于检测和监测皮下部位的mPEG-聚（丙氨酸）水凝胶包埋的MIN6细胞是有用的非侵入性工具。
