Effect of Hydrogels and LipoxinA4 on Rat Periodontal Fibroblasts in-vitro

Poly-ethylene-glycol (PEG) based hydrogels have been recognized as a suitable vehicle for the delivery of bioactive molecules. One such bioactive, LipoxinA4 (LXA4) promotes resolution of inflammation and minimizes localised alveolar bone loss in experimentally induced periodontitis. Objective: To evaluate the effect of three types of PEG based porous hydrogels and for optimal dosage of LXA4 on rat periodontal fibroblast proliferation, viability and cell attachment and the expression of cell markers. Methods: Biodegradability of PEG based hydrogels were tested in 0.01M phosphate buffer saline, at 37±0.5°C in incubator. Established primary rat periodontal fibroblast cells (1x104) were used to evaluate the effects of PEG based porous gels and LXA4 on the proliferation (Countess, Invitrogen), viability (LIVE/DEAD® kit, Invitrogen) and cell attachment (confocal microscopy), from 1-5 days in culture. Statistical analysis was done using ANOVA, Bonferroni multiple comparison post tests. Results: All PEG based hydrogels degraded after 28 days. At days 1 and 3, proliferation of POSS treated fibroblasts was significantly lower (p<0.001) compared to the control. At day 5, the viability of POSS treated fibroblasts was significantly reduced compared to day 3 POSS and day 5 Boltorn® treated groups. In LXA4 treated groups, at day 3, proliferation and viability of fibroblasts of 1µg LXA4 and 2µg LXA4 treated groups was significantly lower (p<0.001) than 500ng LXA4 and sham treated groups. However at day 5, fibroblasts cell numbers in 1µg LXA4 and 500ng LXA4 treated groups were significantly higher (p<0.01) compared to 2µg LXA4 and sham treated groups. Confluence and cell attachment of fibroblast cells were significantly diminished on the surface of PEG triblock copolymer treated groups. Conclusion: Low doses of LXA4, PEG triblock or Boltorn®20 copolymers did not inhibit proliferation and attachment of fibroblasts over time. Acknowledgments ADRF and IBRA.