# The Effect of the Overexpression or Addition of IGF1 and FGF2 in Human Chondrocytes Included in a Fibrin Matrix and Cultivated in a Dynamic Environment

## TL;DR

This study explores how adding or overexpressing IGF1 and FGF2 in chondrocytes within a fibrin matrix affects cartilage protein synthesis in a dynamic environment.

## Contribution

The novel contribution is demonstrating that IGF1 and FGF2 enhance hyaline cartilage protein synthesis in a dynamic culture system.

## Key findings

- Collagen type II and glycosaminoglycans increased during incubation with IGF1 and FGF2.
- Collagen type I expression decreased under the same culture conditions.
- Continuous agitation improved nutrition but required growth factors to regulate collagen proteins.

## Abstract

Hyaline cartilage is a highly specialized tissue. When injured, its repair capacity is low, which results in the massive destruction of the articular surface. Using tissue engineering and genetic engineering techniques, it is possible to provide a suitable microenvironment providing chondrocyte growth factors involved in the development of hyaline cartilage proteins, as well as cell proliferation and differentiation. Our aim was to stimulate the synthesis of an extracellular matrix via the chondrocytes included in a fibrin matrix through the addition or overexpression of IGF1 and/or FGF2, while maintaining a constant agitation of the culture medium. Collagen type II and glycosaminoglycans increased during the entire incubation time. In contrast, collagen type I decreased its expression under the same culture conditions, transfecting or supplementing growth factors to chondrocytes. However, chondrocytes that were not transfected or supplemented showed a general increase in the proteins analyzed in this study. The presence of IGF1 and FGF2 increased the protein synthesis of the hyaline cartilage, regardless of which one was the source of growth factors. Continuous agitation using the spinner flask allows for the adequate nutrition of chondrocytes included in the fibrin matrix. However, they require growth factors to up-regulate or down-regulate collagenous proteins.