Comparison of cytotoxicity and wound healing effect of carboxymethylcellulose and hyaluronic acid on human corneal epithelial cells.
OBJECTIVE
To investigate the cytotoxic effect on human corneal epithelial cells (HCECs) and the ability to faciliate corneal epithelial wound healing of carboxymethylcellulose (CMC) and hyaluronic acid (HA).


METHODS
HCECs were exposed to 0.5% CMC (Refresh plus(®), Allergan, Irvine, California, USA) and 0.1% and 0.3% HA (Kynex(®), Alcon, Seoul, Korea, and Hyalein mini(®), Santen, Osaka, Japan) for the period of 30min, and 4, 12, and 24h. Methyl thiazolyl tetrazolium (MTT)-based calorimetric assay was performed to assess the metabolic activity of cellular proliferation and lactate dehydrogenase (LDH) leakage assay to assess the cytotoxicity. Apoptotic response was evaluated with flow cytometric analysis and fluorescence staining with Annexin V and propiodium iodide. Cellular morphology was evaluated by inverted phase-contrast light microscopy and electron microscopy. The wound widths were measured 24h after confluent HCECs were scratch wounded.


RESULTS
The inhibitory effect of human corneal epithelial proliferation and cytotoxicity showed the time-dependent response but no significant effect. Apoptosis developed in flow cytometry and apoptotic cells were demonstrated in fluorescent micrograph. The damaged HCECs were detached from the bottom of the dish and showed the well-developed vacuole formations. Both CMC and HA stimulated reepithehlialization of HCECs scratched, which were more observed in CMC.


CONCLUSIONS
CMC and HA, used in artificial tear formulation, could be utilized without any significant toxic effect on HCECs. Both significantly stimulated HCEC reepithelialization of corneal wounds.
Department of Ophthalmology, School of Medicine, Pusan National University, Yangsan 626-770, Gyeongnam Province, Korea ; Biomedical Research Institute, Pusan National University Hospital, Busan 602-739, Korea.
Jong Soo
JS
Lee
Department of Ophthalmology, School of Medicine, Kosin University, Busan 602-702, Korea.
Seung Uk
SU
Lee
Department of Ophthalmology, the Affiliated Hospital of Medical College, Qingdao University, Qingdao 266003, Shandong Province, China.
Cheng-Ye
CY
Che
Department of Ophthalmology, School of Medicine, Pusan National University, Yangsan 626-770, Gyeongnam Province, Korea ; Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan 626-770, Gyeongnam Province, Korea.
Ji-Eun
JE
Lee
carboxymethylcellulose; corneal wound healing; cytotoxicity; human corneal epithelial cells; hyaluronic acid