Proceedings of the National Academy of Sciences of the United States of America
Tissue engineering holds the promise of replacing damaged or diseased tissues and organs. The use of autologous donor cells is often not feasible because of the limited replicative lifespan of cells, particularly those derived from elderly patients. Proliferative arrest can be overcome by the ectopic expression of telomerase via human telomerase reverse transcriptase (hTERT) gene transfection. To study the efficacy and safety of this potentially valuable technology, we used differentiated vascular smooth muscle cells (SMC) and vascular tissue engineering as a model system.
Journal of Tissue Engineering and Regenerative Medicine
Tissue engineering involves the use of synthetic or natural materials as a scaffold to support the growth of replacement tissue or organs. The use of autologous cells to populate the scaffold avoids problems associated with rejection; however, a major limitation of this approach is the finite lifespan of primary cells in culture. This finite lifespan is due to the shortening of telomeres, short repetitive sequences of DNA located at the ends of eukaryotic chromosomes.
Adipose tissue engineering has recently gained significant attention from materials scientists as a result of the exponential growth of soft tissue filler procedures being performed within the clinic. While several injectable materials are currently being marketed for filling subcutaneous voids, they often face limited longevity due to rapid resorption. Their inability to encourage natural adipose formation or ingrowth necessitates repeated injections for a prolonged effect and thus classifies them as temporary fillers.
Traditional ex vivo culture setups fail to imitate the native tissue niche, leading to cellular senescence, phenotypic drift, growth arrest and loss of stem cell multipotency. Growing evidence suggests that surface topography, substrate stiffness, mechanical stimulation, oxygen tension and localised density influence cellular functions and longevity, enhance tissue-specific extracellular matrix deposition and direct stem cell differentiation.
Engineered tissues represent a natural environment for studying cell physiology, mechanics, and function. Cellular interactions with the extracellular matrix proteins are important determinants of cell physiology and tissue mechanics. Dysregulation of these parameters can result in diseases such as cardiac fibrosis and atherosclerosis. In this report we present a novel system to produce hydrogel tissue constructs (HTCs) and to characterize their mechanical properties. HTCs are grown in custom chambers and a robotic system is used to indent them and measure the resulting forces.
As the potential range of stem cell applications in tissue engineering continues to grow, the appropriate scaffolding choice is necessary to create tightly defined artificial microenvironments for each target organ. These microenvironments determine stem cell fate via control over differentiation. In this study we examined the specific effects of scaffold stiffness on embryonic mesenchymal progenitor cell behavior. Mechanically distinct scaffolds having identical microstructures and surface chemistries were produced utilizing core-shell electrospinning.
Osteoarthritis and cartilage / OARS, Osteoarthritis Research Society
OBJECTIVE: To investigate whether icariin, which is a widely used pharmacological constituent in traditional Chinese herbal medicine, can be a potential promoting compound for cartilage tissue engineering. DESIGN: Icariin was added into cell-hydrogel constructs derived from neonatal rabbit chondrocytes and collagen type I. The chondrogenic gene expressions and the synthesis of cartilage matrix of the seeded cells were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Biochemical assay.