Purification and biocompatibility of fermented hyaluronic acid for its applications to biomaterials.
BACKGROUND
Hyaluronic acid (HA) is of importance due to its diverse applications in pharmaceuticals and medical devices such as dermal filler, adhesion barriers, carrier for cells and bioactive molecules as well as scaffold biomaterials for tissue engineering. Evaluations of purification and biocompatibility of HA are required for its applications to biomaterials.


RESULTS
After synthesizing HA by fermentation of streptococcus zooepidemicus for 25 hr, extensively purification of the fermented broth was performed to remove impurities using a filtration process for insoluble components and cells, and diverse adsorbents for soluble impurities. Its in vitro biocompatibility has been evaluated by measurement of cell counting and assay of cell live and dead. 60% yield of white HA powder was obtained, having 15-17 dL/g intrinsic viscosity with a molecular weight of approximately 1,000 kDa. While low molecular weight impurities and insoluble impurities were successfully removed using a ultrafiltration membrane with 50 KDa molecular weight cut, endotoxins, high molecular weight proteins and nucleic acids were removed from the broth by employing adsorbents such as alumina and activated carbons. Alumina showed the best results for the removal of endotoxins, all of the activated carbons were very effective in the removal of high molecular weight proteins and nucleic acids. The purified HA solution showed excellent cell compatibility with no cell damages as observed by both measurement of cell proliferation and observation of cell viability.


CONCLUSIONS
We obtained high molecular weight HA with excellent biocompatibility as judged by both measurement of cell proliferation and viability, indicating high possibility of its applications to biomaterials.
School of Life Science and Biotechnology, Korea University, Seoul, 136-701 Republic of Korea ; Department of Bioplant, Hanmi Pharm. Co, Pyeongtaek, 451-805 Korea.
Sungchul
S
Choi
Department of Bioplant, Hanmi Pharm. Co, Pyeongtaek, 451-805 Korea.
Woncheol
W
Choi
Department of Bioplant, Hanmi Pharm. Co, Pyeongtaek, 451-805 Korea.
Sekweon
S
Kim
Department of Chemical Engineering, Seoul National University of Science and Technology, Seoul, 139-743 Korea ; Convergence Institute of Biomedical Engineering and Biomaterials, Seoul National University of Science and Technology, Seoul, 139-743 Korea.
Su-Yeon
SY
Lee
Department of Chemical Engineering, Seoul National University of Science and Technology, Seoul, 139-743 Korea ; Convergence Institute of Biomedical Engineering and Biomaterials, Seoul National University of Science and Technology, Seoul, 139-743 Korea.
Insup
I
Noh
School of Life Science and Biotechnology, Korea University, Seoul, 136-701 Republic of Korea.
Chan-Wha
CW
Kim
Activated carbon; Adsorption; Biomaterials; Hyaluronic acid; Purification