Tissue engineering (TE) is continuously evolving assimilating inputs from adjacent scientific areas and their technological advances, including nanotechnology developments that have been spawning the range of available options for the precise manipulation and control of cells and cellular environments. Simultaneously, with the maturation of the field, TE has a growing and marked impact in other fields, such as cancer and other diseases research, enabling tri-dimensional (3D) tumor/tissue models of increased complexity that more closely resemble living tissue dynamics, playing a decisive role in the development of new and improved therapies. Nevertheless, TE is still struggling with translational issues. On this matter, the advent of personalized and precision medicine has opened new perspectives, particularly with the striking evolutions enabled by 3D bioprinting technologies. Based on a modified methodology grounded in the past years' approach, we have identified and reviewed some of the most high-impact publications on the topics that are revolutionizing TE and helping to define the future directions of the field, namely: (1) New trends in TE: Personalized/precision regenerative medicine and 3D bioprinting, (2) Contributions of TE to other fields: microfabricated tissue-engineered 3D models for cancer and other diseases research, and (3) Diagnostic and theranostic tools: monitoring and real-time control of TE systems.
12 April 2012 in Journal of Tissue Engineering and Regenerative Medicine
Current treatments for tendon injuries often fail to fully restore joint biomechanics leading to the recurrence of symptoms, and thus resulting in a significant health problem with a relevant social impact worldwide. Cell-based approaches involving the use of stem cells might enable tailoring a successful tendon regeneration outcome. As growth factors (GFs) powerfully regulate the cell biological response, their exogenous addition can further stimulate stem cells into the tenogenic lineage, which might eventually depend on stem cells source. In the present study we investigate the tenogenic differentiation potential of human- amniotic fluid stem cells (hAFSCs) and adipose-derived stem cells (hASCs) with several GFs associated to tendon development and healing; namely, EGF, bFGF, PDGF-BB and TGF-β1. Stem cells response to biochemical stimuli was studied by screening of tendon-related genes (collagen type I, III, decorin, tenascin C and scleraxis) and proteins found in tendon extracellular matrix (ECM) (Collagen I, III, and Tenascin C). Despite the fact that GFs did not seem to influence the synthesis of tendon ECM proteins, EGF and bFGF influenced the expression of tendon-related genes in hAFSCs, while EGF and PDGF-BB stimulated the genetic expression in hASCs. Overall results on cellular alignment morphology, immunolocalization and PCR analysis indicated that both stem cell source can be biochemically induced towards tenogenic commitment, validating the potential of hASCs and hAFSCs for tendon regeneration strategies.