Gellan gum films for effective guided bone regeneration

Guided bone regeneration (GBR) films with bioabsorbable characteristics have been employed for surgical procedures to prevent the growth of scar tissue in the bone graft site. GBR films provide an isolated space over regions with defective tissues and prevent the invasion of fibrous connective tissue into the defect space, and can thus promote bone healing. In this study, we employed Gellan gum (GG) as viable film material and evaluated its potential for GBR applications. Three types of GG films (1%, 1.5%, 2%) were prepared. The tensile strength increased with an increase of film thickness. The 2% and 1.5% GG films were 2.87 and 1.96 times, respectively, the tensile strength of the 1% GG film. However, 1%, 1.5% and 2% GG films were degraded in strength by about 60%, 50% and 20% of initial value, respectively, after 30-day shaking test. Consequently, standardized, transosseous, and critical-sized (cavity of 6 mm) skull defects were made in Sprague-Dawley (SD) rats, and the defective regions were covered with the 2% GG film. After 2 months of recovering, the GG film covered regions showed a clear boundary space between connective tissue and evidenced collagen would not grow into the space of the bone defect. It is concluded that the 2% GG film has great promise for application in GBR in general.