Modified Keratinocytes Reconstitute Epidermis

Wounds transplanted with either transfected or normal keratinocytes restored their epithelial barrier function significantly faster than nontransplanted controls, according to a paper from Brigham and Women's Hospital, Boston, in conjunction with Agracetus, published in the Proceedings of the National Academy of Sciences.

The study, conducted in pig models (which are similar to human skin in morphology and turnover time), involved the formation of 170 reproducible standardized full-thickness skin wounds on the backs of 13 anesthesized pigs. Under aseptic conditions, chambers, serving as in vivo cell culture devices, were applied to each wound. 22 wounds were treated with lacZ (the gene coding for beta-galactosidase) transfected keratinocytes, and 10 other wounds were treated with human growth hormone gene transfected keratinocytes. 71 wounds were treated with non-transfected keratinocytes and 67 with saline and antibiotics.

The researchers report that skin biopsies showed that by day six, wounds into which either unmodified or retrovirally- transfected keratinocytes had been transplanted were covered with a thin, gradually thickening epithelium. Epithelialization did not occur until day 12 in saline controls. The re-establishment of the normal epithelialized barrier was also indicated by impermeability to protein. The transplanted keratinocytes, whether normal or transfected, behaved in a characteristic fashion.