In Vitro and In Vivo Biocompatibility Of ReOss® in Powder and Putty Configurations

Abstract

This study evaluated comparatively two configurations (powder and putty) of a composite biomaterial based on PLGA (Poly(lactide-co-glycolide)/nanoescale hydroxyapatite (ReOss®, Intra-Lock International) through microscopic morphology, in vitro cytotoxicity, biocompatibility and in vivo response as a bone substitute. SEM and EDS characterized the biomaterials before/after grafting. Cytocompatibility was assessed with murine pre-osteoblasts. Osteoconductivity and biocompatibility were evaluated in White New Zealand rabbits. Both configurations were implanted in the calvaria of eighteen animals in non-critical size defects, with blood clot as the control group. After 30, 60 and 90 days, the animals were euthanized and the fragments containing the biomaterials and controls were harvested. Bone blocks were embedded in paraffin (n=15) aiming at histological and histomorphometric analysis, and in resin (n=3) aiming at SEM and EDS. Before implantation, the putty configuration showed both a porous and a fibrous morphological phase. Powder revealed porous particles with variable granulometry. EDS showed calcium, carbon, and oxygen in putty configuration, while powder also showed phosphorus. After implantation EDS revealed calcium, carbon, and oxygen in both configurations. The materials were considered cytotoxic by the XTT test. Histological analysis showed new bone formation and no inflammatory reaction at implant sites. However, the histomorphometric analysis indicated that the amount of newly formed bone was not statistically different between experimental groups. Although both materials presented in vitro cytotoxicity, they were biocompatible and osteoconductive. The configuration of ReOss® affected morphological characteristics and the in vitro cytocompatibility but did not impact on the in vivo biological response, as measured by the present model.

The Use of Lactide Polymers in Bone Tissue Regeneration in Dentistry—A Systematic Review

“…The studies included in the review varied with the type of conduction, material compared and form of applied material. Type of conduction: in vivo [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 14 , 15 , 16 , 17 , 18 , 20 , 21 , 22 , 23 , 25 , 26 , 27 , 28 , 64 , 65 , 66 ] or in vitro [ 19 , 24 , 29 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 ], type of surgery, and whether there was a material compared [ 3 , 6 , 8 , 9 , 10 , 11 , 13 , 14 , 15 , 16 , 18 , 21 , 24 , 26 , 27 , 28 ,…”

“…The researchers decided to have a more general look at assessing the clinically valid properties of chosen materials and their use in bone regeneration. The primary study outcome is that despite differences in the form of applied material and type of surgery, the bioresorbable materials possess good biocompatibility [ 4 , 5 , 29 ] osteoinductive properties [ 3 , 4 , 13 , 19 , 25 ] and other clinically valid properties benefitting bone regeneration procedures. This could be concluded by observing faster new bone formation [ 7 , 9 , 11 , 13 , 20 , 64 , 76 ], good bone quality postsurgically [ 3 ], no inflammation in situ [ 5 , 25 , 26 , 64 ], lower immune response [ 9 ], no sign of infection [ 22 , 23 , 66 ], suppression of apoptosis [ 71 ], visible neoangiogenesis [ 5 , 9 ], more serum fibronectin and vitronectin absorption [ 71 ], increased growth factor production and protein absorption [ 71 ] and no cytotoxicity in situ [ 4 , 6 ].…”

“…In the last years, many researchers focused on studies on the use of a mix of polylactides with bio-ceramics in bone surgery. These materials are used in procedures such as bone augmentation surgeries prior to the implant placement [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ], sinus lift operations [ 12 , 13 ], orthognathic surgeries [ 14 , 15 , 16 ], maxillofacial osteotomies [ 17 , 18 ], periodontal disease treatment [ 19 ], supplementation of bone defects after tumour removal [ 20 ] and treatment of traumas of bones of the masticatory system and facial skeleton [ 21 , 22 , 23 ]. Depending on the study, the biomaterials are introduced in the form of membranes [ 19 , 24 ], screws [ 13 , 14 , 15 , 16 , 17 , 18 , 20 , 21 , 23 , 25 , 26 , 27 ], plates [ 14 , 15 , 16 , 17 , 18 , 21 , 23 , 26 ], nanotubes [ 6 ], trays [ 3 ], distraction devices [ 7 ], discs [ 28 ], filaments [ 29 ] and sheets [ 22 ].…”