Bioactivity of Biphasic Calcium Phosphate Granules, the Control of a Needle-Like Apatite Layer Formation for Further Medical Device Developments.

Biphasic calcium phosphate (BCP) bioceramics (hydroxyapatite/tricalcium phosphate, or HA/TCP) for tissue engineering and drug delivery systems is a unique know-how. A mechanical mixture of HA and TCP does not lead to such bioactive ceramics. The wet elaboration conditions of calcium-deficient apatite (CDA) or CDHA, followed by sintering, converts it into TCP and HA.

Beta-tricalcium phosphate ceramic triggers fast and robust bone formation by human mesenchymal stem cells.

Due to their osteoconductive and inductive properties, a variety of calcium phosphate (CaP) scaffolds are commonly used in orthopaedics as graft material to heal bone defects. In this study, we have used two CaP scaffolds with different hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) ratios (MBCP®; 60/40 and MBCP ®; 20/80) to investigate their intrinsic capacity to favour human bone marrow stem cells (hBMSCs) osteogenic differentiation capacity. We report that MBCP ® showed in in vitro culture model a higher rate of calcium ion release in comparison with MBCP®.

A doxycycline inducible, adenoviral bone morphogenetic protein-2 gene delivery system to bone.

We report the novel use of a tuneable, non-integrating viral gene delivery system to bone that can be combined with clinically approved biomaterials in an 'off-the-shelf' manner. Specifically, a doxycycline inducible Tet-on adenoviral vector (AdTetBMP-2) in combination with mesenchymal stromal cells (MSCs), fibrin and a biphasic calcium phosphate ceramic (MBCP®) was used to repair large bone defects in nude rats. Bone morphogenetic protein-2 (BMP-2) transgene expression could be effectively tuned by modification of the doxycycline concentration.

Smart scaffolds: the future of bioceramic.

The commercial offer for bioceramic bone substitutes is very large, however, the prerequisites for applications in bone reconstruction and tissue engineering, are most often absent. The main criteria being: on the one hand physico-chemical features providing surgeons with an injectable and/or shapeable biomaterial; on the second hand the multi-scale bioactivity leading to osteoconduction and osteoinduction properties. In order to obtain greater suitability according to the nature of the bone defect to be treated, new bone regeneration technologies, "smart scaffolds" must be developed and optimize to support suitable Ortho Biology.

Osteoinduction of biphasic calcium phosphate scaffolds in a nude mouse model.

Bioceramics combined with isolated stem cells, or with total bone marrow, constitute the main strategies under consideration in the field of bone tissue engineering. In the present preclinical study, two biphasic calcium phosphate scaffolds currently on the market, MBCP® and MBCP+®, with different hydroxyapatite/β-tricalcium phosphate ratio, were implanted ectopically in a nude mouse model. These scaffolds were supplemented either with human mesenchymal stromal cells, or with human total bone marrow, or rat total bone marrow.

Tolerance and osteointegration of TricOs(TM)/MBCP(®) in association with fibrin sealant in mastoid obliteration after canal wall-down technique for cholesteatoma.

Conclusion: The TricOs™/MBCP(®) and fibrin sealant composite was a convenient, effective, and well-tolerated material for mastoid cavity filling and immediate reconstruction of the external auditory meatus after cholesteatoma surgery with canal wall down (CWD).

Objective: To assess the tolerance and osteointegration of a bone graft substitute, TricOs™/MBCP(®), in association with fibrin sealant for filling the mastoid cavity after cholesteatoma surgery using the CWD technique.

Methods: In this prospective observational study 57 patients with cholesteatoma suitable for CWD were recruited from April 2006 to April 2008 and followed up for 1 year.

[Intra-articular distal radial fracture with lunate fossa rotated, about 4 cases: interest of surgical procedure by volar medial approach].

Introduction: Intra-articular distal radial fractures in young subjects occur in severe trauma. Articular reduction needs to be anatomical. We report four cases with the particularity of having a 90° or 180° rotated lunate fossa.

Novel analysis model for implant osseointegration using ectopic bone formation via the recombinant human bone morphogenetic protein-2/macroporous biphasic calcium phosphate block system in rats: a proof-of-concept study.

Purpose: The osseointegration around titanium mini-implants installed in macroporous biphasic calcium phosphate (MBCP) blocks was evaluated after incubation with recombinant human bone morphogenetic protein-2 (rhBMP-2) in an ectopic subcutaneous rat model.

Methods: Mini-implants (φ1.8×12 mm) were installed in MBCP blocks (bMBCPs, 4×5×15 mm) loaded with rhBMP-2 at 0.

Irreducible traumatic posterior hip dislocation with entrapment and a buttonhole effect.

The authors reported the case of a 27-year-old man who sustained an irreducible postero-lateral traumatic dislocation of the hip with capsular and labral entrapment. Initial X-rays showed only a small acetabular fragment. After two attempts to reduce the hip with muscle paralysis under general anaesthesia failed, the patient was treated by immediate open reduction through a postero-lateral approach.

Biphasic bone substitute and fibrin sealant for treatment of benign bone tumours and tumour-like lesions.

Purpose: Bone defects resulting from tumour resection or curettage are most commonly reconstructed with autologous bone graft which is associated with limited availability and donor site morbidity. Recent research has focussed on synthetic biomaterials as bone graft substitutes. The aim of this study was to assess the safety and efficiency of a bone substitute as an alternative for autologous bone in the treatment of benign bone tumours and tumour-like lesions.

Osteoconductive properties of poly(96L/4D-lactide)/beta-tricalcium phosphate in long term animal model.

The objective of this study was to determine the effect of calcium phosphate mineral content on the bone in-growth at the expense of composite of co-polylactide polymer charged with 2 different ratios of β-TCP granules (10 and 24 w-% of β-TCP). The evaluation was realized in a long term rabbit bone model. After 24, 48 and 76 weeks, the implants were examined by micro CT, scanning electron microscopy (SEM) using backscattered electron (BSE) and light microscopy (polarized and blue light microscopy).

Mandibular segmental defect regenerated with macroporous biphasic calcium phosphate, collagen membrane, and bone marrow graft in dogs.

Objective: To reconstruct segmental mandibulectomy using calcium phosphate ceramics and collagen membrane with a delayed bone marrow grafting in experimental animals.

Design: Defects of segmental mandibulectomy were filled with calcium phosphate granules and wrapped with a collagen membrane in 4 dogs and left empty as a control in 2 dogs. Two months later, a bone marrow graft was injected into the center of the implants.

Biofunctionality of MBCP ceramic granules (TricOs) plus fibrin sealant (Tisseel) versus MBCP ceramic granules as a filler of large periprosthetic bone defects: an investigative ovine study.

We aimed to quantify bone colonization toward an untreated titanium implant with primary stability following filling of the defect with micromacroporous biphasic calcium phosphate (MBCP) granules (TricOs) or MBCP granules mixed with fibrin sealant (Tisseel). Medial arthrotomy was performed on the knees of 20 sheep to create a bone defect (16 mm deep; 10 mm diameter), followed by anchorage of a titanium screw. Defects were filled with TricOs or TricOs-Tisseel granules, a perforated MBCP washer, a titanium washer and titanium screw.

Radiation effects on bone healing and reconstruction: interpretation of the literature.

Objective: Reconstructing irradiated mandibles with biomaterials is still a challenge but little investigated. We collected data that could help us understand studies in the field of regeneration with biomaterials and irradiated bone.

Study Design: Systematic review of the literature.

Alveolar ridge augmentation in irradiated rabbit mandibles.

Oral carcinomas are frequently treated with a nonsegmental mandibulectomy plus radiotherapy. Improving the quality of life of these patients depends on the possibilities for dental rehabilitation. The aim of this study was to increase the alveolar ridge height.

Developments in injectable multiphasic biomaterials. The performance of microporous biphasic calcium phosphate granules and hydrogels.

Calcium phosphate bioceramic granules associated with hydrosoluble polymers were developed as bone substitutes for various maxillofacial and orthopaedic applications. These injectable bone substitutes, support and regenerate bone tissue and resorb after implantation. The efficiency of these multiphasic materials is due to the osteogenic and osteoconductive properties of the microporous biphasic calcium phosphate.

Comparison of two bone substitute biomaterials consisting of a mixture of fibrin sealant (Tisseel) and MBCP (TricOs) with an autograft in sinus lift surgery in sheep.

Objectives: The aim of this study was to assess the efficacy and safety of macroporous biphasic calcium phosphate (MBCP())/fibrin grafts (TricOs((R)))/(Tisseel((R))) for sinus lift augmentation in sheep. Autologous bone grafts were used as a positive control, and dental implants were placed to assess the efficiency of the composite.

Materials And Methods: A total of 12 adult sheep (24 maxillary sinuses) were randomized to receive sinus lift augmentation with MBCP()/fibrin grafts obtained by either simultaneous or sequential addition of thrombin and fibrinogen to MBCP(), or autologous bone grafts.

[Mandibular reconstruction for the treatment of oral carcinomas: state of the art and perspectives].

Introduction: Mandibular reconstruction in head and neck oncology uses a number of techniques whose results are inconsistent and whose indications do not benefit from consensus.

Materials And Methods: A review of the literature allowed us to assemble the available knowledge on current mandibular reconstruction techniques, their functional results, and the research perspectives.

Results And Discussion: Marginal resections lead to dental rehabilitation problems, which can be palliated by alveolar enhancement techniques but whose results have not been validated in cases subjected to irradiation.

Injectable biphasic calcium phosphate bioceramic: The HYDROS concept.

A new biphasic calcium phosphate ceramic material has been developed in our laboratory. It is composed of 60% of hydroxyapatite and 40% of beta-tricalcium phosphate, based on three granulometries (submicron, round microporous 80-200 mum and macro microporous 0.5-1 mm particles) and hydrated with water leading the formation of a putty filler for bone repair.

Porous beta tricalcium phosphate scaffolds used as a BMP-2 delivery system for bone tissue engineering.

Macroporous beta tricalcium phosphate (beta-TCP) scaffolds were evaluated as potential carriers and delivery systems for bone morphogenetic protein-2 (BMP-2). Chemical etching was performed to increase the available surface and thus the protein loading. X-ray diffraction and infrared spectrocopy analyses confirmed the preparation of pure beta-TCP scaffolds.

Effects of high doses of ionising radiation on bone in rats: a new model for evaluation of bone engineering.

The purpose of this study was to assess the effects of high doses of ionising radiation on the histology and healing of bone in an experimental model of 12 inbred rats. Ten of the rats had external irradiation of a single dose of 30 or 45 Gy on the hind limbs, which is equivalent to 2 or 3 times the routine doses used for treatment in humans. Three weeks later, two bony defects were created on their left sides, and the animals were killed 12 or 18 weeks after irradiation.

Clinical, radiological and histological evaluation of biphasic calcium phosphate bioceramic wedges filling medial high tibial valgisation osteotomies.

We report clinical, radiological and histological findings following high tibial valgisation osteotomy (HTVO) using micro-macroporous biphasic calcium phosphate wedges fixed with a plate and locking screws. From 1999 to 2002, 43 knees were operated on and studied prospectively. All underwent clinical and radiological follow-up at days 1, 90, and 365 to evaluate consolidation and bone substitute interfaces.

Reconstruction of irradiated bone segmental defects with a biomaterial associating MBCP+(R), microstructured collagen membrane and total bone marrow grafting: an experimental study in rabbits.

The bone tissue engineering models used today are still a long way from any oncologic application as immediate postimplantation irradiation would decrease their osteoinductive potential. The aim of this study was to reconstruct a segmental critical size defect in a weight-bearing bone irradiated after implantation. Six white New Zealand rabbits were immediately implanted with a biomaterial associating resorbable collagen membrane EZ(R) filled and micro-macroporous biphasic calcium phosphate granules (MBCP+(R)).

A comparison between bone reconstruction following the use of mesenchymal stem cells and total bone marrow in association with calcium phosphate scaffold in irradiated bone.

The purpose of this study was to compare bone reconstruction using either mesenchymal stem cells (MSCs) or total bone marrow (TBM) in association with biphasic calcium phosphate (BCP) granules after irradiation in a rat model. Three weeks after an external irradiation of the hind limbs of rats, four bone defects were created per animal. The defects were filled with either BCP alone, or with a mixture of BCP and TBM, or with a mixture of BCP and MSCs (adipose-derived or bone marrow-derived MSCs).

Bioactive materials in endodontics.

Endodontic treatment in dentistry is a delicate procedure and many treatment attempts fail. Despite constant development of new root canal filling techniques, the clinician is confronted with both a complex root canal system and the use of filling materials that are harmful for periapical tissues. This paper evaluates reported studies on biomaterials used in endodontics, including calcium hydroxide, mineral trioxide aggregate, calcium phosphate ceramics and calcium phosphate cements.