In vitro degradation of triple layered poly (lactic-co-glycolic acid) composite membrane composed of nanoapatite and lauric acid for guided bone regeneration applications

Bone healing has been a great challenge in orthopaedic and dentistry fields. In one of the ways for overcoming this, a barrier membrane is used in guided bone regeneration (GBR) applications to cover and aid the healing of bone defects. In this study, lauric acid (LA) and nanoapatite (NAp) were incorporated into poly(lactic-co-glycolic acid) (PLGA) matrices to form triple layered composite membranes for potential use in GBR applications. LA and NAp were added to introduce antimicrobial and bioactive properties, respectively, to the composite membrane. The membranes were fabricated using a combined techniques of solvent casting - thermally induced phase separation (TIPS) - solvent leaching in a single step. In vitro degradation behaviour of the new composite membrane system was studied for 24 weeks in phosphate buffer saline (PBS) at 37 °C; pH = 7.4, to match the bone healing period in GBR applications. Immersion of membrane samples was carried out at pre-determined time intervals of 1, 2, 4, 8, 12, 16, 20 and 24 weeks. Physical changes such as weight loss and water uptake were measured after each time period and relatively monitored pH changes in post-immersed PBS solutions. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) was used to assess morphology changes and presence of NAp particles on the membrane surfaces after withdrawing from PBS. The entire weight loss for the membranes was only up to 22% over 24 weeks of incubation, which suggests its structural integrity and potential use as a physical barrier in GBR applications.