Biphasic Calcium Phosphate Bioceramics for Orthopaedic Reconstructions: Clinical Outcomes

BCP are considered the most promising biomaterials for bone reconstruction. This study aims at analyzing the outcomes of patients who received BCP as bone substitutes in orthopaedic surgeries. Sixty-six patients were categorized according to the etiology and morphology of the bone defects and received scores after clinical and radiographic evaluations. The final results corresponded to the combination of both parameters and varied from 5 (excellent result) to 2 or lower (poor result). Most of the patients who presented cavitary defects or bone losses due to prosthesis placement or revision, osteotomies, or arthrodesis showed good results, and some of them excellent results. However, patients with segmental defects equal or larger than 3 cm in length were classified as moderate results. This study established clinical parameters where the BCP alone can successfully support the osteogenic process and where the association with other tissue engineering strategies may be considered

Effect of calcium phosphate compound (MZF-CaP) with and without fluoride in preventing bone loss in ovariectomized rats

Zinc (Zn) has been shown to inhibit osteoclast differentiation, promote osteoblast activity, and enhance the bone formation. Zinc-containing calcium phosphate (Zn-TCP) implanted in rabbit femoral defect was demonstrated to stimulate bone formation. Other studies demonstrated that calcium phosphate compounds (MZF-CaP) incorporating magnesium (Mg2+), zinc and fluoride (F-) when administered either by injection or orally were effective in preventing bone loss (osteoporosis) induced by estrogen deficiency (ovariectomy) in a rat model. The objective of the present study was to investigate the preventive effect of similar compound, with F (MZF-CaP-L, MZF-CaP-H) and without F (MZ-CaP-L), when injected in ovariectomized (OVX) rats. MZF-CaP-L and MZ-CaP-L were prepared by precipitation at 90oC and MZF-CaP-H was prepared by sintering MZF-CaP-L at 900oC. The release of the ions from acidic buffer was determined. Suspensions of Zn-TCP, MZF-CaP-H, MZF-CaP-L and MZ-CaP-L (617 μg in 0.2 ml of 1% sodium alginate saline solution) were injected intramuscularly under anesthesia into 5-week-old OVX rats on Zn-deficient diet. One week after surgery, bone mineral density (BMD) and bone mineral content (BMC) of the rat femurs were measured using X-ray CT. The injections and X-ray CT and Zn ion plasma measurements were repeated every week for 12 weeks. The rats were sacrificed and the femurs removed after 12 weeks. Bone mechanical strength was evaluated using the three-point bending test. MZ-CaP-L (without F), compared to the other compounds, showed the highest increase in the Zn2+ ion plasma concentration, and the highest BMD, BMC and mechanical strength

Neurotoxins during the Renaissance. Bioarcheology of Ferrante II of Aragon (1469–1496) and Isabella of Aragon (1470–1524)

Abstract We show that statistical modeling of analytical results is useful in providing insights into metabolism and disease in bioarcheology. Our results also imply that during the Renaissance in Europe widespread pollution of the biosphere with heavy metals such as mercury and lead affected the Italian nobility at that time. The activity of biologic clocks which control metabolism and autonomic nervous system (ANS) function can be gleaned from the analysis of hair. This provides a means of assessing the health of individuals who lived some six centuries before the present and allows the reconstruction of disease from archived tissues such as hair

Effect of calcium phosphate compound (MZF-CaP) with and without fluoride in preventing bone loss in ovariectomized rats

Zinc (Zn) has been shown to inhibit osteoclast differentiation, promote osteoblast activity, and enhance the bone formation. Zinc-containing calcium phosphate (Zn-TCP) implanted in rabbit femoral defect was demonstrated to stimulate bone formation. Other studies demonstrated that calcium phosphate compounds (MZF-CaP) incorporating magnesium (Mg2+), zinc and fluoride (F-) when administered either by injection or orally were effective in preventing bone loss (osteoporosis) induced by estrogen deficiency (ovariectomy) in a rat model. The objective of the present study was to investigate the preventive effect of similar compound, with F (MZF-CaP-L, MZF-CaP-H) and without F (MZ-CaP-L), when injected in ovariectomized (OVX) rats. MZF-CaP-L and MZ-CaP-L were prepared by precipitation at 90oC and MZF-CaP-H was prepared by sintering MZF-CaP-L at 900oC. The release of the ions from acidic buffer was determined. Suspensions of Zn-TCP, MZF-CaP-H, MZF-CaP-L and MZ-CaP-L (617 μg in 0.2 ml of 1% sodium alginate saline solution) were injected intramuscularly under anesthesia into 5-week-old OVX rats on Zn-deficient diet. One week after surgery, bone mineral density (BMD) and bone mineral content (BMC) of the rat femurs were measured using X-ray CT. The injections and X-ray CT and Zn ion plasma measurements were repeated every week for 12 weeks. The rats were sacrificed and the femurs removed after 12 weeks. Bone mechanical strength was evaluated using the three-point bending test. MZ-CaP-L (without F), compared to the other compounds, showed the highest increase in the Zn2+ ion plasma concentration, and the highest BMD, BMC and mechanical strength

Calcified Algae for Tissue Engineering.

This book presents the latest advances in marine structures and related biomaterials for applications in both soft- and hard-tissue engineering, as well as controlled drug delivery

Simultaneous incorporation of magnesium and carbonate in apatite: effect on physico-chemical properties

Synthetic apatites are widely used both in the dental and the orthopaedic fields due to their similarity in composition with the inorganic phase of hard tissues. Biologic apatites are not pure hydroxyapatite (HA), but are calcium-deficient apatites with magnesium and carbonate as minor but important substituents. The aim of the present study was to produce a more soluble biomaterial through the simultaneous substitution of magnesium and carbonate in the apatite structure to accelerate the degradation time in the body. The physico-chemical and dissolution properties of unsintered magnesium and carbonate-substituted apatite (MCAp) with similar Mg/Ca molar ratio (0.03) and varying C/P molar ratio were evaluated. The resultant powders were characterised using several techniques, such as FTIR, TGA, XRD, ICP and SEM, while the release of calcium ions in a pH 6 solution was monitored using a Ca-ion selective electrode. The results showed a decrease of crystallite size and an increase in the release of calcium to the medium as the carbonate content in the samples increased

Physico-chemical-mechanical and in vitro biological properties of calcium phosphate cements with doped amorphous calcium phosphates.

Calcium phosphate cements (CPCs) are successfully used as bone substitutes in dentistry and orthopaedic applications. This study investigated the physico-chemical-mechanical properties of and in vitro biological properties (cell response) of CPCs prepared with amorphous calcium carbonate phosphate (ACCP) doped with magnesium (ACCP-Mg), zinc (ACCp-Zn) or fluoride (ACCP-F) ions. The experimental CPC consisted of alpha-TCP, doped ACCP, and MPCM powders as matrix and biphasic calcium phosphate (BCP) granules. X-ray diffraction analysis showed that the matrix converted to apatite with poor crystallinity (reflecting small crystal size) after setting for 24 h, while BCP remained apparently unchanged. Cements with ACCP-F (F-CPC) had shorter setting times and greater compressive strength compared to cements with ACCP-Mg (Mg-CPC) or ACCP-Zn (Zn-CPC). Scanning electron microscopy (SEM) showed that crystals set on Mg-CPC and Zn-CPC were smaller compared to those on F-CPC. The total porosity of Mg-CPC was greater compared to Zn-CPC or F-CPC. Osteoblast-like cells, MC3T3-E1, remained viable and maintained their ability to express alkaline phosphatase in contact with the CPCs with doped ACCPs