Calcium phosphate regeneration

Bio-nanocomposites based on calcium phosphates can perform other innovative fundions such as acting as a reservoir for the controlled release of bioadive compounds once the material is implanted in the bone defect. For instance, the incorporation of a morphogenetic protein that promotes bone regeneration in an HAP-alginate-collagen system [110] or a vitamin in a Ca-deficient HAP-chitosan nanocomposite [111] are recent examples of this kind of application. 

Liquid membranes of the water-in-oil emulsion type have been extensively investigated for their applications in separation and purification procedures [6.38]. They could also allow extraction of toxic species from biological fluids and regeneration of dialysates or ultrafiltrates, as required for artificial kidneys. The substrates would diffuse through the liquid membrane and be trapped in the dispersed aqueous phase of the emulsion. Thus, the selective elimination of phosphate ions in the presence of chloride was achieved using a bis-quaternary ammonium carrier dissolved in the membrane phase of an emulsion whose internal aqueous phase contained calcium chloride leading to phosphate-chloride exchange and internal precipitation of calcium phosphate [6.1]. 

As well as being used as a scaffold for tissue engineering, Hutchens et al. [64] described the creation of a calcium-deficient hydroxyapatite, the main mineral component of bone. Calcium phosphate particles were precipitated in BC by consecutive incubation of calcium chloride and sodium phosphate solutions. Initial tests with osteoblasts in the in vitro evaluation showed that solid fusion between the material and the bone tissue is possible. Hence, this material is a good candidate for use as a therapeutic implant to regenerate bone and heal osseous damage. 

The regeneration of biomineralized skeletal tissues by echinoids using magnesian-calcite is reminiscent of that observed for the precipitation of calcium phosphate in regenerating fractured vertebrate bones (Section 8.05.3.7.2). These organisms and their cell systems are completely... 

The tissue engineering concept offers development of useful substrates for repair replacement or regeneration of organs and tissues. Hydroxyapatite (Cio(PC>4)6(OH)2, HA) is the major constituent of the bone and teeth. Deposition of calcium phosphate... 

Khan, A.F., Saleem, M., Afzal, A., Ali, A., Khan, A., and Khan, A.R. (2014) Bioactive behavior of silicon substituted calcium phosphate based bioceramics for bone regeneration. Mater. Sci. Eng. C, 35, 245-252. 

Teller, M., Becker, P., and Neumann, H.G. (2005) Antibiotic laoded sol-gel derived calcium phosphate/silica composite for bone regeneration. Key Eng. Mater., 284-286, 415-418. 

Gauthier O, Muller R, von Stechow D, Lamy B, Weiss P, Bouler JM, et al. In vivo bone regeneration with injectable calcium phosphate biomaterial a three-dimensional micro-computed tomographic, biomechanical and SEM study. Biomaterials. 2005 Sep 26(27) 5444-53. 

Regenerated cellulose. See Cellophane Regent 12XX. See Calcium phosphate monobasic monohydrate Regulus. See Polyimide, thermoplastic Rebels Less Salt Blend. See Potassium chloride... 

Polak SJ, Lan Levengood SK, Wheeler MB, Maki AJ, Claik SG, Wagoner Johnson AJ (2011). Analysis of the roles of microporosity and BMP-2 on multiple measures of bone regeneration and healing in calcium phosphate scaffolds. Ada Biomater 2011 7 1760-71. 

However, there is both research and clinical evidence showing nanometer particles released from calcium phosphates may largely impair the abihty of BMSCs to proliferate and mature into a functional osteoblast phenotype [64]. This opposite evidence indicates that more and thorough research on utilizing stem cell and calcium phosphate nanoparticle for bone repair and regeneration is required before possible clinical applications. 

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