Bioceramic-polymer composites

Bone is a natural composite comprised of type I collagen and calcium phosphate minerals, of which nanocrystalline apatite is the main component [39, 40]. Certain osteoconductive bioceramics exert an effect on bone cell attachment and growth factor binding or release, and can accelerate the treatment of bone defects [41-43]. Polymer composite scaffolds can be produced, via electrospinning, which contain a specific amount of electrical charge in order to form non-woven fibrous meshes with fibre dimensions in the nano- to microscale [44-46]. 

Bonfield, W. (1993). Design of bioactive ceramic-polymer composites. An Introduction to Bioceramics, pp. 299-303, Hench, L. L, and Wilson,]., eds., Singapore World Scientific. 

If a nearly inert material is implanted into the body it initiates a protective response that leads to encapsulation by a nonadherent fibrous coating about 1 i.m thick. Over time this leads to complete isolation of the implant. A similar response occurs when metals and polymers are implanted. In the case of bioactive ceramics a bond forms across the implant-tissue interface that mimics the bodies natural repair process. Bioactive ceramics such as HA can be used in bulk form or as part of a composite or as a coating. Resorbable bioceramics, such as tricalcium phosphate (TCP), actually dissolve in the body and are replaced by the surrounding tissue. It is an important requirement, of course, that the... 

The effects of the surface modification of p-CaSi03 on the electrospun poly(butylene sucdnate)/p-CaSi03 composite fibers were investigated (Zhang and Chang 2009). Dodecyl alcohol can be esterified on the surface of p-CaSiOj to modify the bioceramics and prepare the composite fibrous materials with improved properties. Therefore, PBSU/p-CaSiOj composite nanofiber membranes were fabricated by incorporating the surface-modified and surface-unmodified p-CaSiOj into the polymer matrix. 

Yunos, D.M., Bretcanu, O., and Boccaccini, A.R. (2000) Polymer-bioceramic composites for tissue engineering scaffolds. Joumol of Materials Science, 43, 4433-4442. 

Mourino, V, CattaUni, J.P., Roether, J.A., Dubey, R, Roy, L, Boccaccini, A.R., 2013b. Composite polymer-bioceramic scaffolds with drug deUvery capabUity for bone tissue engineering. Expert Opinion on Drug Delivery 10 (10), 1353-1356. 

Other inorganic materials, such as biphasic calcium phosphate (BCP) with CMC have been prepared for new classes of composite materials. Multiphasic materials such as bioceramic show high compressive properties in addition to containing water-soluble polymers and are considered good ionic carriers for the formation of ECM. This composite material provided adequate injectable properties and nontoxic responses, demonstrating its potential for the repair of AC (De Freitas et al., 2012). 

The development of mineral-organic composite materials offers the possibility of combining the favorable properties of bioceramics such as the HAP, alumina or titanium dioxide with the molding capacity of biocompatible polymers (polymethylmethacrylate) PMMA [KHO 92], poly(L-lactic) acid PLLA [ROD 95], poly (ethylene) PE pOW 91]). It is also conceivable to attain a value of the modulus of elasticity near to that of the bone. 

DMA can also be used to investigate the effect of sterilisation on the structural and thermal properties of polymers and composites intended for biomedical use. Due to the sensitivity of some polymers to heat and solvent attack, one option to sterilise would be to y -irradiate. In a study investigating the properties of composite materials consisting of bioceramic fillers. 

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