Comparison of the cellular composition of two different chondrocyte-seeded biomaterials and the results of their transplantation in humans.

Our study compares the histological and immunohistochemical cellular composition of two different chondrocyte-seeded biomaterials and the results of their transplantation. Our study cohort included 21 patients, comprising 19 men and two women with a mean age of 32 years, who were affected by single chondral lesions of the femoral condyles. These patients were enrolled in our study and treated with arthroscopic implantation of the tissue Hyalograft C and/or Brno culture. Brno culture bioengineered with a fibrin-based scaffold contains round cells showing features of differentiated chondrocytes expressing S-100 protein and α-smooth muscle actin. In contrast, in the case of Hyalograft C, the scaffold was made up of a fibrillar network composed of biomaterial fibres of the esters of hyaluronic acid and cells resembling fibroblasts and myofibroblasts and expressing only α-smooth muscle actin. The average size of the defects was 2.5 cm2. Patients were evaluated using the standardized guidelines of the International Knee Documentation Committee. During the comparison of bioptic samples obtained from both patient cohorts, we did not observe any important differences in the histological makeup of the newly formed cartilage. The histological analysis of these two groups of homogeneous patients shows that this bioengineered approach, under proper indications, may offer favourable and stable clinical results over time, in spite of the different matrix and cellular composition of the two transplants used.