Online Monitoring Of Mechanical Properties Of 3D Tissue Engineered Constructs For Quality Assessment

El Haj, A. J.; Reinwald, Y.; Baganinchi, P.; Gamal, W.; Yang, Y.

Abstract

Introduction: Monitoring the maturation of engineered tissues prior to implantation into the patient is important for defining quality and manufacturing criteria. Key properties include scaffold integrity and mechanical properties. Novel non-invasive 3D imaging modalities are required providing rapid results and translational solutions. Elastography allows the mapping of mechanical properties by measuring the deformation in correlation to external mechanical loading, but is limited in terms of resolution and sensitivity. To overcome these drawbacks elastography has been coupled with optical coherence tomography and a hydrostatic pressure bioreactor into a new image modality, HP-OCE.

Methods: Hydrogels were prepared by dissolving agarose in dH2O (0.5%, 1.0% and 1.5%). hMSC (1×105) were incorporated before gelation to prepare cellular gels. Scaffolds were imaged utilizing OCT during mechanical stimulation at 1, 5, 10, 15 and 25 kPa at 1Hz frequency in the hydrostatic force bioreactor. Displacements maps were generated using elastography algorithms.

Results and Discussion: Phase-resolved OCE detects small displacements in heterogeneous tissue, the presence of cells or hybrid constructs. Differences were detected for hybrid hydrogels prepared from agarose compared to hydrogels. Interfaces between stiffer and softer gels can be identified. A novel HP-OCE, with cyclic compression as the external excitation generated by hydrostatic pressure was established. Phase-resolved OCE algorithms were applied to determine the scaffolds displacement in OCT phase-based images of various tissue phantoms. Our results indicate that HP-OCE allows real-time non-invasive monitoring of the displacement and strains of tissue phantoms enabling the investigation of scaffold degradation, material interfaces as well as changes in scaffold porosity.

Citation

El Haj, A. J., Reinwald, Y., Baganinchi, P., Gamal, W., & Yang, Y. (2016). Online Monitoring Of Mechanical Properties Of 3D Tissue Engineered Constructs For Quality Assessment.

• Start Date: Dec 11, 2016
• End Date: Dec 14, 2016
• Online Publication Date: Dec 1, 2016
• Publication Date: Dec 1, 2016
• Deposit Date: Jun 12, 2023
• Publisher: Mary Ann Liebert
• Volume: 22
• Pages: S75