Bioactive elastin-like-recombinamer (ELR) membranes guide bone regeneration in rabbit critical size calvarial defects.

Objectives: To examine the effectiveness of non-mineralised and pre-mineralised elastin-like recombinamer (ELR) membranes in guided bone regeneration (GBR) in a pre-clinical rabbit model.

Materials and methods: Three pre-mineralised ELR membranes (D1, D2 and D8) and a non-mineralised (D0) membrane, along with a collagen membrane (C+) and an empty defect were randomly allocated in rabbit calvarial defects of critical size. Four weeks post-implantation the animals were euthanized and bone fill was assessed using micro CT and histological evaluation.

Results: Using micro CT, all ELR membranes led to similar bone density, as unassisted healing and healing using a resorbable collagen membrane. A trend for superior bone fill with the D2 pre-mineralised ELR membrane was observed. Histologically, at this early time-point the ELR membranes successfully guided GBR in the defects, similarly to the control collagen membrane, and additionally led to the formation of a thin woven bone layer at the top of the cranial defect bridging between the margins of the defect.

Conclusions: As early as 4 weeks post-implantation, the ELR membranes successfully guided bone regeneration in this rabbit critical size calvarial model and a trend for superior regeneration was observed with pre-mineralised for 2 days ELR membranes. The ELR membranes led to the formation of a bony bridge parallel to the membrane suggesting bioactivity beyond occlusion of the defect.

Clinical relevance: These bioactive alloplastic membranes may succesfully serve as alternatives to allogenic membranes in guided bone regeneration.