Stem cell theranostics has received much attention for noninvasively monitoring and tracing transplanted therapeutic stem cells through imaging agents and imaging modalities. Despite the excellent regenerative capability of stem cells, their efficacy has been limited due to low cellular retention, low survival rate, and low engraftment after implantation. Three-dimensional (3D) cell printing provides stem cells with the similar architecture and microenvironment of the native tissue and facilitates the generation of a 3D tissue-like construct that exhibits remarkable regenerative capacity and functionality as well as enhanced cell viability. Thus, 3D cell printing can overcome the current concerns of stem cell therapy by delivering the 3D construct to the damaged site. Despite the advantages of 3D cell printing, the in vivo and in vitro tracking and monitoring of the performance of 3D cell printed tissue in a noninvasive and real-time manner have not been thoroughly studied. In this review, we explore the recent progress in 3D cell technology and its applications. Finally, we investigate their potential limitations and suggest future perspectives on 3D cell printing and stem cell theranostics.

中文翻译：

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3D细胞打印的组织类似物：治疗学的新平台

干细胞治疗学已通过成像剂和成像方式无创地监测和追踪移植的治疗性干细胞受到了广泛的关注。尽管干细胞具有出色的再生能力，但由于细胞滞留率低，存活率低和植入后植入率低，其功效受到了限制。三维（3D）细胞打印为干细胞提供了与天然组织相似的结构和微环境，并促进了3D组织样构建体的生成，该构建体表现出显着的再生能力和功能性以及增强的细胞活力。因此，通过将3D构建体递送至受损部位，3D细胞印刷可以克服当前对干细胞疗法的关注。尽管3D细胞打印具有优势，但体内和体外跟踪和非侵入和实时方式监控3D单元印刷组织的性能还没有被彻底研究。在这篇综述中，我们探索了3D单元技术及其应用的最新进展。最后，我们调查了它们的潜在局限性，并提出了有关3D细胞打印和干细胞治疗学的未来展望。