Advanced Tools for Tissue Engineering: Scaffolds, Bioreactors, and Signaling

Abstract

This article contains the collective views expressed at the second session of the workshop "Tissue Engineering--The Next Generation,'' which was devoted to the tools of tissue engineering: scaffolds, bioreactors, and molecular and physical signaling. Lisa E. Freed and Farshid Guilak discussed the integrated use of scaffolds and bioreactors as tools to accelerate and control tissue regeneration, in the context of engineering mechanically functional cartilage and cardiac muscle. Edward Guo focused on the opportunities that tissue engineering generates for studies of mechanobiology and on the need for tissue engineers to learn about mechanical forces during tissue and organ genesis. Martha L. Gray focused on the potential of biomedical imaging for noninvasive monitoring of engineered tissues and on the opportunities biomedical imaging can generate for the development of new markers. Robert Tranquillo reviewed the approach to tissue engineering of a spectrum of avascular habitually loaded tissues- blood vessels, heart valves, ligaments, tendons, cartilage, and skin. Jeffrey W. Holmes offered the perspective of a "reverse paradigm''--the use of tissue constructs in quantitative studies of cell-matrix interactions, cell mechanics, matrix mechanics, and mechanobiology. Milica Radisic discussed biomimetic design of tissue-engineering systems, on the example of synchronously contractile cardiac muscle. Michael V. Sefton proposed a new, simple approach to the vascularization of engineered tissues. This session stressed the need for advanced scaffolds, bioreactors, and imaging technologies and offered many enlightening examples on how these advanced tools can be utilized for functional tissue engineering and basic research in medicine and biology.

Articular cartilage repair by genetically modified bone marrow aspirate in sheep

“…The cornerstones on which a successful tissue engineering-based strategy will likely be built include an adequate supply of repair cells, sufficient induction of those cells by growth factor signalling, and a biocompatible scaffold conducive to the repair process. 24 The approach to focal cartilage defect repair described in this study uses vector-laden coagulated bone marrow aspirates for gene delivery to the defect site. Aspirated autologous bone marrow contains progenitor cells, the matrix is completely natural and native to the host, and the constitutive fibrin fibres adhere the whole construct to the surface of the defect.…”

A Mathematical Model for Analyzing the Elasticity, Viscosity, and Failure of Soft Tissue: Comparison of Native and Decellularized Porcine Cardiac Extracellular Matrix for Tissue Engineering

“…16,17 Accordingly, for materials based on the extracellular matrix (ECM), as well as for many other viscoelastic biomaterials used in tissue engineering, not only must the stiffness be matched (average, time-independent), but the other viscoelastic parameters, which describe the time and rate dependency of the mechanical response to deformation, must also fit. 14 In recent publications, we demonstrated the applicability of the decellularized ECM for tissue engineering applications, and the comparability of acellular and native tissue, including vascular grafts, 18 thin myocardial patches, 2 and thick 3,5 left ventricle cardiac wall constructs. In particular, a perfusion-driven decellularization procedure (Trypsin-and Triton-based, more elaborately described in the Supplementary Data [Supplementary Data are available online at www.liebertpub.com/tec]) was found to achieve high acellularity of the thick porcine cardiac ECM as validated by histological analyses showing no cellular remains.…”

“…Introduction R ecent reports published by our group [1][2][3][4][5] and others [6][7][8][9][10][11][12][13][14] have demonstrated the use of constructs made of decellularized cardiac tissue as scaffolds for tissue engineering. Such scaffolds, to achieve clinical success, must have structural and mechanical properties that closely match human tissue.…”

Pluripotent Stem Cells and Their Dynamic Niche

“…They offer biophysical cues encouraging cells to differentiate or/and produce ECM prior to implantation in vivo [293]. In general, bioreactors meet the following applications in regenerative medicine-1: they provide spatially uniform cell distribution, 2: they deliver physiological relevant concentrations of oxygen and carbon dioxide as well as nutrients in the culture medium, 3: they support mass transport to the core of the tissue engineered construct facilitating cell survival throughout tissue-engineered constructs, 4: they provide physical stimuli to regulate stem cell differentiation and proliferation, 5: they facilitate tissue development and accelerate construct maturation [287,[294][295][296][297]. Studies utilising mechanical forces for the direction of stem cell fate and tissue development are summarised in Table 4.…”