Biomimetic evaluation of β tricalcium phosphate prepared by hot isostatic pressing.

Two types of completely densified β-TCP tablets were synthesized from a stoichiometric β-TCP powder. The first ones (TCP) were conventionally sintered, while the second ones (TCP-T) were sintered and treated by hot isostatic process (HIP). The HIP produced completely densified materials with relative densities greater than 99.

New antibacterial microporous CaP materials loaded with phages for prophylactic treatment in bone surgery.

Hydroxyapatite and beta-tricalcium phosphate (β-TCP) are materials commonly used in bone repair. The most important problem occurring in bone repair surgery is bacterial infection which is usually overcome by treatment with antibiotics. Currently, emergence of multidrug resistant strains has led to development of alternative treatments such as phage therapy.

Prolonged local antibiotics delivery from hydroxyapatite functionalised with cyclodextrin polymers.

Per-operative infection is a common complication for bone-graft surgery. Combining antiseptic agents with graft materials may offer a solution by increasing local drug concentration at target sites. Aiming to achieve a sustained local antibiotic (ATB) delivery for a widely applied bone substitute material - hydroxyapatite (HA), we attempted incorporating hydroxypropyl-beta-cyclodextrin polymer (polyHPbetaCD) into microporous HA via impregnating either in a CD monomers mixture solution or a pre-synthesized CD polymer solution, followed by thermal fixation processing.

beta-TCP microporosity decreases the viability and osteoblast differentiation of human bone marrow stromal cells.

Association of osteoprogenitor cells to calcium phosphate ceramics is currently under intense investigation, for its considered ability to induce bone formation and therefore to allow the successful repair of large bone defects. However, if the first experimental and clinical studies provided promising results, lack of new bone formation has been reported in a large number of animal experiments. In this context and since it has been reported that in some conditions, calcium phosphate ceramic microstructure induces ectopic bone formation, we investigated the effects of ceramic microporosity on the behavior of osteoprogenitor cells for the development of hybrid materials.

Repair of osteochondral defects with autologous chondrocytes seeded onto bioceramic scaffold in sheep.

At present, the most popular biomaterials used in cartilage tissue engineering are synthetic polymers. However, problems-such as acidic by-product accumulation and side effects in local or systemic inflammatory reactions during in vivo degradation-are drawing much attention. The polymers are also highly hydrophobic and degrade within 4 weeks, allowing insufficient time to support neocartilage formation.

Relationship between bioceramics sintering and micro-particles-induced cellular damages.

We performed experimental studies to confirm the hypothesis that cellular damages occurring around implanted biphasic bioceramics could be related to a micro-particles release because of an insufficient sintering. First, an in vitro cytotoxicity study was performed on four biphasic ceramic (BCP) samples. Without treatment of the extraction medium, a cytotoxicity was observed, although after centrifugation this cytotoxicity disappeared in all samples.

The biodegradation mechanism of calcium phosphate biomaterials in bone.

This study was undertaken to understand the biodegradation mechanisms of calcium phosphate (Ca-P) biomaterials with different crystallization. Two types of sintered Ca-P porous ceramic (HA and beta-TCP) and a Ca-P bone cement (CPC) were implanted into cavities drilled in rabbit femoral and tibiae condyles. The results have shown that a material biodegradation was rapid in the beta-TCP and the CPC, but very weak in the HA.