Mold fabrication and biological assessment of porous DNA-chitosan complexes

A previous study revealed that DNA-chitosan complex prepared from the reaction between native DNA and chitosan in aqueous solution has suitable porosity for cell seeding, is nontoxic, and causes only a mild soft-tissue response. This simple and easy fabrication method for porous DNA-chitosan complex provides for a wide variety of applications as a scaffold material. The present study evaluated whether rinsing with PBS solution can fabricate DNA-chitosan complex in a mold and the histopathological responses of rat soft tissues to fabricated DNA-chitosan complexes. DNA-chitosan complex paste was prepared by mixing distilled water and freeze-dried water-rinsed DNA-chitosan complex powder. A DNA-chitosan complex disk could be fabricated by rinsing with PBS buffer and subsequently freeze-drying the DNA-chitosan complex paste in the mold. Thus, a wide range of applications of DNA-chitosan complex for tissue engineering can be anticipated using the present easy fabrication method. The porosity of the disk was 85%, and many pores were visible in the DNA-chitosan complex (before fabrication) and in the fabricated DNA-chitosan disk. The values of the complex disks gradually reduced in the tissues although 60% of disks remained in the tissues. In conclusion, an easy fabrication method for making porous DNA-chitosan complex disks was developed. It was found that the fabrication method can delay the biodegradation of the DNA-chitosan complex disk without serious tissue responses in vivo. DNA-chitosan complex is promising as a scaffold material, and a wide range of applications of DNA-chitosan complex for tissue engineering are anticipated.