Possibility of preventive correction of dystrophic changes in intervertebral disc by cell engineering technique

Abstract

Objective. To study a possibility of cultured chondroblast transplantation into nucleus pulposus of the intact intervertebral disc for correction of structural-functional disorders at early stages of degeneration. Material and Methods. Chondroblasts isolated from the spine of newborn wild-type puppies were cultured in appropriate media. Second passage chondroblasts were transplanted into intervertebral disc of wild-type mature dogs. Specimens were extracted at 14 days, 1, 3, and 6 months and studied using biochemical, in-depth morphohistochemical, and ultrastructural analyses. Aggrecan gene expression in a transplant was analyzed by a polymeraze chain reaction. Results. Second-passage chondroblasts transplanted into intervertebral disc realize their genetic program in several steps. During first two weeks an adaptation of chondroblasts to metabolic conditions in vivo is observed. The process of cell functioning consists in auto- and paracrine regulation, and cells are under steady-state condition. The second stage includes activation of synthetic and mitotic processes, formation of extracellular matrix, and amplification of the ultrastructural organization of chondroblasts. At the third stage isogene groups, columnar structures, and chondronic organization are registered. This testifies to multilevel organization of cell functioning providing a formation of organospecific hyaline cartilage. Conclusion. Chondroblasts transplanted into appropriate metabolic medium are subjected to multilevel evolutionary fixed regulation resulting in formation of specific hyaline cartilage which can facilitate structural-functional integrity of the intervertebral disc.