Bone defect reconstruction with a novel biomaterial containing calcium phosphate and aluminum oxide reinforcement

Abstract

Background Reconstruction of metaphyseal fractures represents a clinical challenge for orthopedic surgeons. Especially in osteoporotic bone, these fractures are frequently accompanied by osseous substance defects. In order to ensure rapid mobilization of patients, high stability requirements must be met by osteosynthesis. Various bone graft materials have been introduced in the past, such as autologous bone or exogenous bone substitute materials. These are used as bone void fillers or as augmentation techniques to ensure safe fixation of osteosynthesis. New calcium phosphate-based bone void-filling materials could be a promising alternative to autologous bone or to the currently and widely used polymethylmethacrylate (PMMA)-based cement. The aim of this study was to evaluate a novel paste-like bone void filler in vivo and in vitro with regard to biocompatibility and osteoconductivity. Methods In addition to in vitro testing of cell compatibility using pre-osteoblasts (MC3T3-E1), 35 Wistar rats were treated in vivo with implantation of various material mixtures based on calcium phosphate and aluminum oxide reinforcement in a metaphyseal drill hole defect. After 4 weeks, an examination by micro-computed tomography (μCT) and histology was performed. Results The in vitro analysis showed good biocompatibility with a high cell survival of osteoblasts. In the in vivo experiments, a significantly higher bone ingrowth compared to the empty defect was shown by μCT and histological analysis. Here, the group receiving material reinforced with aluminum oxide (Al2O3) showed a bone volume/tissue volume (BV/TV) of 89.19% compared to a BV/TV of 83.14% for the empty defect (p = 0.0013). In the group treated with a polysaccharide matrix, no increase in BV/TV was observed given a mean ratio of 80.14%. Scoring of histological sections did not reveal a significant difference between CaP and CaP that was substituted with Al2O3. Conclusion The results of this study show an encouraging first step towards the development of new pasty, bone void-filling materials. We demonstrated that a new paste-like bone-filling material, based on calcium phosphate granulates and aluminum oxide to provide strength, exhibits good biocompatibility and osteoconductivity. Further biomechanical test in an osteoporotic animal model will have to be performed, to prove feasibility in metaphyseal defects.

The Preliminary Assessment of New Biomaterials Necessitates a Comparison of Direct and Indirect Cytotoxicity Methodological Approaches

“…There is a high demand to develop new, improved strategies to support the impaired or ‘’insufficient’’ bone-regeneration process [ 9 , 10 ]. One of the most promising methods to improve bone healing is implantation using regenerative biomaterials [ 11 , 12 ].…”

A composite of polymethylmethacrylate, hydroxyapatite, and β‐tricalcium phosphate for bone regeneration in an osteoporotic rat model

“…27,28 However, a composite system of bone cement or scaffold with desirable mechanical properties and bone capacity is suitable for vertebroplasty. [29][30][31][32][33] Therefore, we aimed to develop and modify the PMMA bone cement in combination with osteoconductive and biodegradable materials including HA, and β-TCP for vertebroplasty. Morphological structures and mechanical properties of these specimens were evaluated.…”

“…PMMA bone cement has some defects such as hardness greater than osteoporotic bone, poor osteointegration property, and lacking of bone regeneration capacity 27,28 . However, a composite system of bone cement or scaffold with desirable mechanical properties and bone regeneration capacity is suitable for vertebroplasty 29–33 . Therefore, we aimed to develop and modify the PMMA bone cement in combination with osteoconductive and biodegradable materials including HA, and β‐TCP for vertebroplasty.…”

A novel vertical aligned mesoporous silica coated nanohydroxyapatite particle as efficient dexamethasone carrier for potential application in osteogenesis

“…The bone defect is a common problem in clinic that can be attributed to many diseases such as traumatic injury, bone surgery and abnormality [1]. In most of the occasions, the conventional bone substitutes containing calcium and phosphate are considered as the ideal biomaterials can obtain satisfied repair [2]. Unfortunately, sometimes the regeneration is limited or even failed, particularly in pathetic condition such as osteoporosis and diabetes mellitus [3,4].…”