Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy.
Department of Nanomedicine, Houston Methodist Research Institute, 6670 Bertner Avenue, R8-216, Houston, TX 77030, USA; Department of Electronics and Telecommunications, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy.
J Mech Behav Biomed Mater. 2018 Jun;82:133-144. doi: 10.1016/j.jmbbm.2018.03.023. Epub 2018 Mar 21.
Cell transplantation in bioengineered scaffolds and encapsulation systems has shown great promise in regenerative medicine. Depending on the site of implantation, type of cells and their expected function, these systems are designed to provide cells with a physiological-like environment while providing mechanical support and promoting long-term viability and function of the graft. A minimally invasive 3D printed system termed neovascularized implantable cell homing and encapsulation (NICHE) was developed in polylactic acid for subcutaneous transplantation of endocrine cells, including pancreatic islets. The suitability of the NICHE for long term in vivo deployment is investigated by assessing mechanical behavior of both fresh devices under simulated subcutaneous conditions and NICHE retrieved from subcutaneous implantation in pigs. Both experimental and numerical studies were performed with a focus on validating the constitutive material model used in the numerical analysis for accuracy and reliability. Notably, homogeneous isotropic constitutive material model calibrated by means of uniaxial testing well suited experimental results. The results highlight the long term durability for in vivo applications and the potential applicability of the model to predict the mechanical behavior of similar devices in various physiological settings.
细胞在生物工程支架和封装系统中的移植在再生医学中显示出巨大的前景。根据植入部位、细胞类型及其预期功能，这些系统旨在为细胞提供类似于生理的环境，同时提供机械支撑，促进移植物的长期存活和功能。一种微创 3D 打印系统，称为血管化可植入细胞归巢和封装（NICHE），是用聚乳酸制成的，用于内分泌细胞（包括胰岛）的皮下移植。通过评估模拟皮下条件下新鲜装置的机械行为以及从猪皮下植入物中取出的 NICHE 的机械行为，研究了 NICHE 用于体内长期部署的适用性。实验和数值研究都侧重于验证数值分析中使用的本构材料模型的准确性和可靠性。值得注意的是，通过单轴测试校准的均匀各向同性本构材料模型很好地符合实验结果。研究结果突出了体内应用的长期耐久性，以及该模型在各种生理环境下预测类似装置的机械行为的潜在适用性。
