Osteoarthritis (OA) is a common chronic disease caused damage on focal area of the articular cartilage and caused by extreme exercise and aging. Current surgical treatments for OA had a series of disadvantages such as fibrocartilaginous tissue formati...
Osteoarthritis (OA) is a common chronic disease caused damage on focal area of the articular cartilage and caused by extreme exercise and aging. Current surgical treatments for OA had a series of disadvantages such as fibrocartilaginous tissue formation and donor site morbidity. Therefore, in order to overcome these problems, researchers developed advanced treatments with the aid of mesenchymal stem cell (MSCs) including (bone-marrow derived stem cells (BMSCs) and adipose-derived stem cell (ADSCs)). Recent stem cell therapies based on tissue engineering and regenerative medicine have been developed combining with scaffolds and exogenous growth factors. MSC has self renewal ability and multipotency that can differentiate into bone/cartilage tissue, and is well known for pro-inflammatory effect within inner body conditions. Additionally MSC can be isolated easily from bone-marrow or adipose tissue with high yields. Therefore, it has been used as a common cell source utilized under various conditions in tissue engineering. For enhanced stem cell differentiation, exogenous growth factors (GFs) are administrated by using various delivery carriers (i.e., micelle, liposome, synthetic polymeric platform etc.). Especially, transforming growth factor-beta family (TGF-β) and insulin-like growth factor (IGF) are widely used as an exogenous growth factor for chondrogenesis of stem cell. IGF-1 and TGF- β could enhance the chondrogenesis of stem cells by developing morphological changes and inducing excretion of extracellular matrix (ECM) components. Hence, tissue engineering strategies for chondrogenesis of stem cells have been developed by varying (1) cell culture methods, (2) exogenous biological cues, (3) composition of ingredients, and (4) modification of scaffolds. This article summarized engineering applications for cartilage regeneration using stem cells, by suggesting (1) co-culture stratgies using MSC and chondrocytes, (2) recent clinical trials for ADSC-mediated joint repair, and (3) optimization of serum types (i.e., bovine serum (BS), new-born calf serum (NCS)) for enhanced chondrogenesis of ADSC. Administration of a single cell population of either stem cells or chondrocytes does not guarantee a full recovery of cartilage defects. Therefore, current tissue engineering approaches using co-culture techniques have been developed to mimic complex and dynamic cellular interactions in native cartilage tissues and facilitate changes in cellular phenotypes into chondrogenesis. Therefore, this article introduces recently developed co-culture systems using two major cell populations of, MSCs and chondrocytes. Furthermore, the present article also summarizes the recent clinical applications utilizing ADSC and its clinical and therapeutic efficacy which evaluated by scoring systems for OA treatment. Current ADSC treatments in clinical system have been developed by direct injection of ADSC with additional compounds such as platelet-rich plasma (PRP) and stromal vascular fraction (SVF) for enhancing differentiation of stem cells. In addition, optimization of serum types for a large-scale stem cell production/culture is also critical parameter to develop a cost-effective and biologically functional chondrogenesis process. Fetal bovine serum (FBS) is the most essential supplement in culture media for cellular proliferation, metabolism, and differentiation. However, due to a limited supply and subsequently rising prices, a series of studies have investigated a biological feasibility of replaceable serums to substitute FBS. Along with the increasing interests to manufacture stem cell-based cellular products, optimizing the composition of culture media including serums and exogenous GFs is of importance. Hence, the effect of BS and NCS on proliferation and chondrogenic differentiation capacity of human ADSCs was evaluated, especially in the chondrogenically supplemented culture condition. Our findings demonstrated that (1) co-culture methods using stem cells with chondrocytes could effectively augment chondrogenesis and stem cell differentiation as compared with monoculture, (2) clinical ADSC treatment could be an effective cell therapy by improving physical function of damaged cartilage sites, and (3) serum types and exogenous supplements of GFs could also be important parameters to optimize culture media composition, especially in order to maintain the enhanced levels of both proliferation and chondrogenic differentiation of ADSCs during expansion. Therefore, it could be speculated that stem cell therapy utilizing stem cell population could be an effective OA treatment in tissue engineering and regenerative medicine.