Noninvasive Analysis of Synthetic and Decellularized Scaffolds for Heart Valve Tissue Engineering

Abstract

Microcomputed tomography (µ-CT) is a nondestructive, high-resolution, three-dimensional method of analyzing objects. The aim of this study was to evaluate the feasibility of using µ-CT as a noninvasive method of evaluation for tissue-engineering applications. The polyurethane aortic heart valve scaffold was produced using a spraying technique. Cryopreserved/thawed homograft and biological heart valve were decellularized using a detergent mixture. Human endothelial cells and fibroblasts were derived from saphenous vein segments and were verified by immunocytochemistry. Heart valves were initially seeded with fibroblasts followed by colonization with endothelial cells. Scaffolds were scanned by a µ-CT scanner before and after decellularization as well as after cell seeding. Successful colonization was additionally determined by scanning electron microscopy (SEM) and immunohistochemistry (IHC). Microcomputed tomography accurately visualized the complex geometry of heart valves. Moreover, an increase in the total volume and wall thickness as well as a decrease in total surface was demonstrated after seeding. A confluent cell distribution on the heart valves after seeding was confirmed by SEM and IHC. We conclude that µ-CT is a new promising noninvasive method for qualitative and quantitative analysis of tissue-engineering processes.

Assessment of Nit-Occlud atrial septal defect occluder device healing process using micro-computed tomography imaging

“…Identifying the tissue coverage was feasible and precise with micro-CT. This high-resolution imaging technique is still emerging in the cardiac field but has shown relevant applications in mapping valve and coronary calcification [ 17 – 20 ], to simulate coronary stent expansion [ 21 – 23 ] and to study cardiac and valve morphology [ 24 – 27 ]. Although in-vivo applications are limited by the high dose of radiation, the development of contrast agents (iodine agents, solutions of tungsten or barium ions) has enabled a reduction of exposure time [ 28 , 29 ].…”

A non-linear mathematical model using optical sensor to predict heart decellularization efficacy

“…Other examples are X-ray Phase Contrast Computed Tomography - PC-CT 38 and Microcomputed Tomography - µ-CT 39 both of which, when focusing on tissue constructs with highly complex geometries and high quality visualization, can be applied to tissues or organs fragments; and, when the goal is to assess density, Computed Tomography – CT showed potential for application to whole organs. Geerts and co-authors 40 demonstrated that rat livers could be monitored using non-contrast CT scan, in which Hounsfield units (HU) could be applied to identify the extent of cell removal, with good correlation and potential to scale-up to larger organs.…”

Nondestructive monitoring of tissue-engineered constructs

“…X-ray and µCT imaging has, therefore, predominately been used in bone and cartilage tissue engineering, for visualizing and analyzing bone structure, osseointegration, and mineralization within the constructs and providing high-resolution images of the scaffold architecture [60]. Besides visualizing the geometry of scaffolds, µCT measurements could also provide information about the cell seeding efficiency and cell distribution on the scaffold by enabling an accurate determination of the total implant volume and thickness, which detectably increased after in vitro cell seeding [27].…”