In vivo nonviral delivery factors to enhance bone repair.

The purpose of the current study was to provide a review of a method for the nonviral delivery of genes into a skeletal defect for the purpose of promoting bone repair. To treat fractures at risk for delayed unions or nonunions, the delivery of plasmid deoxyribonucleic acid by a three-dimensional structural matrix is described. When these gene activated matrices are placed within a wound site, repair fibroblasts are observed migrating into the matrix where they encounter the plasmid deoxyribonucleic acid, take it up, and produce the protein that was defined by the plasmid. In varied animal models including rats, dogs, and sheep, the delivery of plasmids for parathyroid hormone or bone morphogenetic protein promoted bone formation and the healing of critical size defects. These studies show that the delivery of deoxyribonucleic acid to wound repair cells by three-dimensional matrix creates a persistent expression of factors that can promote bone formation.