Characterization of DNA-hyaluronan matrix for sustained gene transfer

DNA-Hyaluronan (DNA-HA) matrix formulations intended for use as gene delivery systems have been developed and their potential for delivering DNA encoding a model therapeutic cytokine, platelet-derived growth factor (PDGF), has been evaluated. The results of enzyme-mediated release kinetics studies suggested that the rate of DNA release from the DNA-HA matrices could be modulated by changing the DNA loading or the degree of crosslinking. SEM imaging of the DNA-HA matrix showed that it was gradually eroded by enzymatic action. The results of gel electrophoresis suggested that there was some degree of interaction between DNA and native HA and that portions of the DNA released from the DNA-HA matrices were associated with crosslinked HA fragments. Only fractions of the DNA released from the DNA-HA matrices were free and the rest was entrapped by HA fragments, which could serve as a mechanism for DNA protection. The results from cell transfection studies using DNA samples collected during the course of release studies confirmed this hypothesis. The PDGF produced by transfection of the DNA released from DNA-HA matrices induced human dermal fibroblast cells to proliferate.