Collagen components of bovine fetal and guinea pig cochlear bone and human stapes

Cartilage tissue engineering with novel nonwoven structured biomaterial based on hyaluronic acid benzyl ester

The aim of this study was to investigate the possibility of using the benzyl ester of hyaluronic acid (HYAFF 11), a recently developed semisynthetic resorbable material, as a scaffold for the culture of human nasoseptal chondrocytes in tissue-engineering procedures of cartilage reconstruction. Different techniques such as immunohistochemistry, scanning electron microscopy, and confocal laser scanning microscopy were used to study the behavior, morphology, and phenotype expression of the chondrocytes, which were initially expanded and then seeded on the material. The nonwoven cell carrier allowed good viability and adhesivity of the cells without any surface treatment with additional substances. Furthermore, the cultured cells expressed cartilage-specific collagen type II, indicating that they were able to redifferentiate within the scaffold of HYAFF 11 and were able to retain a chondrocyte phenotype even after a long period of in vitro conditions. Nevertheless, the expression of collagen type I, which was produced by dedifferentiated or incompletely redifferentiated chondrocytes, was noticeable. Additional data were obtained by subcutaneous implantation of samples seeded with human cells in the in vivo model of the athymic nude mouse. The results after 1 month revealed the development of tissue similar to hyaline cartilage. This study is promising for the use of this scaffold for tissue engineering of cartilage replacements.

Tissue engineering of autologous cartilage transplants for rhinology

In reconstructive surgery there is increasing demand for cartilage transplants to fill defects, especially nose and/or outer ear defects. Tissue engineering is one of the most modern pathways to generate autologous cartilage transplants. Isolated chondrocytes obtained from a tiny patient's biopsy were seeded on bioresorbable preshaped cell carriers to provide a 3-dimensional cell arrangement as in vivo. The combined use of these cell carriers in form of a non-woven mesh and a constant medium perfusion was performed to generate a cartilage-like cell-polymer-construct, which was finally subcutanously implanted in nude mice for full maturation. After explantation of 6 months, expression of cartilage specific extracellular matrix molecules was obvious by using histochemical and immunohistochemical methods. These data show that tissue engineering with isolated multiplied human chondrocytes from a tiny biopsy seeded on bioresorbable polymer is a promising system to generate autologous cartilage transplants for replacements in reconstructive surgery.