**Abstract**

Cartilaginous tissue is mainly present in the joints, and it consists predominantly of type II collagen and glycoproteins, which promote functions of supporting biomechanical forces generated during the ambulation. The cartilage has a very limited regenerating capacity, causing traumas or degenerative diseases in this region difficult to solve. The current treatments for regeneration of the articular cartilages may be conservative or surgical, but they are not very successful, since the damaged tissue is replaced by fibrous tissue or fibrocartilage, with predominantly type I collagen, which present inferior functions. Cellular therapies, biomaterials, and tissue engineering to assist the healing process have been showing great potential. For example, the in vitro chondrogenesis of mesenchymal stem cells (MSCs) is a technique that stimulates undifferentiated cells to transform into chondrocytes, creating a dense mass of aggregated MSCs and an environment with strong cell-cell interactions.

**Keywords:** biomaterials, cell therapy, joint, tissue repair, regenerative medicine

### **1. Introduction**

Joint diseases such as osteoarthritis can cause important lesions in the articular cartilage; in humans, this pathology can affect a significant proportion of patients over 60 years of age, causing a great negative impact on their quality of life. This increased the search for an effective treatment the objective of several researches, often seeking the cooperation of several areas of knowledge; however the difficulty in repairing articular defects in an effective way is becoming a real challenge for medicine [1].

The cartilaginous tissue present in the joints is a highly organized and specialized tissue, presenting several fundamental mechanical proprieties for the maintenance of articular function [1].

The lesions caused in this tissue from trauma or degenerative diseases cause a gradual damage to the tissue, leading to joint pain and consequent impairment in its function, which are difficult to handle clinically [1].

Thus, cases of severe joint disease are usually treated surgically, either through osteotomies and the application of autologous subchondral grafts, reducing the progression of the cartilage lesion and promoting return to joint function, or, in more severe cases, complete articular replacement through prosthesis implantation [2].

Due to the fact that these techniques may present unsatisfactory clinical results, alternative treatments for repair of this type of injury are constant aims of research, mainly in the area of regenerative medicine and tissue engineering, which are commonly working together for the development of different therapies [2].

 With the development of regenerative techniques, such as the use of biomaterials and implantation of autologous cells or tissue, promising results emerged; it was also noticed that the association of several technical modalities was indispensable for obtaining satisfactory clinical recoveries [3].
