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Abstract

The aim of the present study was to assess the effect of three calcium phosphate powders entering in the composition of bone substitute materials on osteoblast-cells activity. These powders were hydroxyapatite (HA) widely used as a biomaterial, nanocrystalline carbonate apatite (C A) very close to bone mineral crystals, and an experimental one: calcium phosphate cement-1 (CPC-1) composed of an amorphous Ca-P phase and brushite. The powders were physico-chemically characterized. The very reactive CPC-1 powder became transformed in cell culture medium: recrystallization of amorphous precursors and hydrolysis of brushite into poorly crystalline apatite occurred. Osteoblast-cells activity was evaluated: for low level of calcium phosphates (>100 microg/ml) CPC-1 enhanced proliferation and, to a lesser degree, differentiation on alkaline phosphatase activity. For 100 microg/ml of powders we observed a great alteration of biological activity of the osteoblasts: evaluation of proliferation indicated an inhibition for all samples, and a decrease of two differentiation markers: alkaline phosphatase activity and osteocalcin release were noticed, suggesting a down regulation due to the presence of large amount of mineral powder.

Combining technologies to create bioactive hybrid scaffolds for bone tissue engineering

“…The effect of Ca-P coating on cell proliferation depends on many factors like Ca-P phase, crystallinity and therewith related degradation behavior of the coating 43 - 46 . We previously reported a decrease in DNA amounts in hMSCs on electrospun fibers coated with a Ca-P layer similar to the one used in the present study as compared with the uncoated fibers, 41 which is in accordance with the results obtained here with hybrid 3DF+ESP scaffolds.…”

Hydroxyapatite Reinforced Chitosan and Polyester Blends for Biomedical Applications

“…Hydroxyapatite has also been evaluated as a reinforcing agent with polymers such as HDPE,9–11 PLLA,12 PMMA,13–15 PHB homopolymer and P(HB‐HV) copolymers,16,17 starch,18,19 and polyester‐ether20 to form bioactive compounds. In addition to increasing the modulus, apatites have biocompatibility with several cell types such as osteoblasts, osteoclasts, fibroblasts, and periodontal ligament cells that are found in calcified tissues 21–23…”

Bioactive Polymeric Composites for Tooth Mineral Regeneration: Physicochemical and Cellular Aspects

“…CaP-related parameters that can affect cellular activity are: dissolution-precipitation behavior, chemical composition, topography and surface energy [12,13,14,15,16,17,18,19,20,21]. In particular, a clear link has been demonstrated between the levels of free Ca and PO 4 ions in culture medium and osteoblastic activities [12,13,14,15,16], as well as early bone formation in vitro and in vivo [7,8].…”

“…In particular, a clear link has been demonstrated between the levels of free Ca and PO 4 ions in culture medium and osteoblastic activities [12,13,14,15,16], as well as early bone formation in vitro and in vivo [7,8]. Any change in Ca/P ratio as a consequence of compositional changes in the CaP phase directly affects ion exchange mechanisms [10].…”

“…Any change in Ca/P ratio as a consequence of compositional changes in the CaP phase directly affects ion exchange mechanisms [10]. On the other hand, the presence of carbonate in the apatitic network of the biomaterial had deleterious effects on osteoblast proliferation and ALP production [13,19]. Grooved CaP surfaces influence the osteoblastic guidance regardless of the nature of substrate [11].…”