Recent development in stem cell isolation methods and expansion under laboratory conditions create an opportunity to use those aforementioned cells in tissue engineering and regenerative medicine. Particular attention is drawn towards mesenchymal stem cells (MSCs) being multipotent progenitors exhibiting several unique characteristics, including high proliferation potential, self-renewal abilities and multilineage differentiation into cells of mesodermal and non-mesodermal origin. High abundance of MSCs found in adipose tissue makes it a very attractive source of adult stem cells for further use in regenerative medicine applications. Despite immunomodulating properties of adipose-derived stem cells (ASCs) and a secretion of a wide variety of paracrine factors that facilitate tissue regeneration, effectiveness of stem cell therapy was not supported by the results of clinical trials. Lack of a single, universal stem cell marker, patient-to-patient variability, heterogeneity of ASC population combined with multiple widely different protocols of cell isolation and expansion hinder the ability to precisely identify and analyze biological properties of stem cells. The above issues contribute to conflicting data reported in literature. We will review the comprehensive information concerning characteristic features of ASCs. We will also review the regenerative potential and clinical application based on various clinical trials.
17 February 2016 in Journal of Materials Science: Materials in Medicine
Collagen and elastin are the main structural proteins in mammal bodies. They provide mechanical support, strength, and elasticity to various organs and tissues, e.g. skin, tendons, arteries, and bones. They are readily available, biodegradable, biocompatible and they stimulate cell growth. The physicochemical properties of collagen and elastin-based materials can be modified by cross-linking. Glutaraldehyde is one of the most efficient cross-linking agents. However, the unreacted molecules can be released from the material and cause cytotoxic reactions. Thus, the aim of our work was to investigate the influence of a safer, macromolecular cross-linking agent—dialdehyde starch (DAS). The properties of hydrogels based on collagen/elastin mixtures (95/5, 90/10) containing 5 and 10 % of DAS and neutralized via dialysis against deionized water were tested. The homogenous, transparent, stiff hydrogels were obtained. The DAS addition causes the formation of intermolecular cross-linking bonds but does not affect the secondary structure of the proteins. As a result, the thermal stability, mechanical strength, and, surprisingly, swelling ability increased. At the same time, the surface properties test and in vitro study show that the materials are attractive for 3T3 cells. Moreover, the materials containing 10 % of DAS are more resistant to enzymatic degradation.
1 March 2016 in Materials Science and Engineering: C