Juyi Li2 Kevin Chen1 Joon Young Lee3 Aaron Sun4 Miriam Rafailovich2

2, Stony Brook University, Stony Brook, New York, United States
1, Mira Costa High School, Manhattan Beach, California, United States
3, Seoul International School, Seongnam City, , Korea (the Republic of)
4, Ed. W Clark High School, Las Vegas, Nevada, United States

Periodontitis, or conventionally “Gum Disease,” begins with the infection, and subsequent inflammation, of gingival tissue and is currently the leading cause of tooth loss in the United States. Though there exists a wide array of methods for treatment of periodontitis, one of the most effective is guided bone regeneration (GBR). GBR consists of applying a barrier membrane to separate inflamed gingival tissue from bone, restricting invasion and allowing regeneration of osteoblasts. Current barrier membranes, however, do not fulfill all the desired properties of high biocompatibility, cell impermeability, and, in particular, high mechanical strength. As such, the following study synthesized novel Gelatin-Pluronic F127 hybrid hydrogels, thoroughly analyzing their in vitro viability as potential cell barrier membranes for use in GBR. Rheological analysis demonstrated high mechanical strength as hybrid hydrogels’ elastic moduli drastically increased with increasing percentages of the chemical cross-linker microbial transglutaminase (mTG). The surface of the hybrid gels was visualized with laser microscope to show topographic changes among different crosslinking density. Cytotoxicity tests were first conducted to show the biocompatibility of hybrid gels. To investigate levels of cell adherence, confocal microscopy was performed on hybrid hydrogels plated with human dermal fibroblasts, which demonstrated significantly reduced cell attachment as compared to pure gelatin. Cell impermeability was further investigated by observing cell migration from gelatin gel to hybrid gel compared with from gelatin to gelatin, with a control setup consisting of Gelatin / Gelatin / Gelatin and an experimental setup of Gelatin / Hybrid / Gelatin. Human dermal fibroblasts plated on gelatin gels migrated through the middle gelatin, but, particularly at the highest mTG concentration, were unable to migrate through middle hybrid gels, showing hybrid hydrogels’ impermeability to cells. Our findings, identifying in vitro high mechanical strength, cell impermeability, and biocompatibility, point to novel Gelatin-Pluronic F127 hybrid hydrogels as promising biomaterials for use as GBR cell barrier membranes in treatment of periodontitis.

[1]Bhatnagar, Divya, et al. "Rheological characterization of novel HA-Pluronic thermoreversible hydrogels." Journal of Chemical and Biological Interfaces 1.2 (2013): 93-99.