Incorporation of bovine serum albumin in calcium phosphate coating on titanium

Abstract

Calcium phosphate (Ca-P) and bovine serum albumin (BSA) were coprecipitated as a coating on commercially pure titanium (cpTi) with a high protein loading (15 wt %) by employing a recently developed wet-chemistry technique. It was observed that the incorporation of BSA significantly modified the morphology, composition, and crystallinity of the Ca-P coating. The Ca-P coating without BSA is a mixture of hydroxyapatite (HA) and octacalcium phosphate (OCP) with sharp-edged thin OCP crystal plates on the top layer, whereas only an HA phase was detected in the Ca-P/BSA coating. The crystal plates in the latter had a more rounded appearance. The Ca-P/BSA coatings were immersed respectively in neutral (pH 7.4) and acidic (starting pH 4.0) phosphate-buffered saline (PBS) at 37 degrees C over a 14-day period. No protein release was detected in the neutral PBS during the immersion; however, a continuous release of BSA was measured in the acidic PBS, subsequently leading to the formation of a very dense and well-adherent composite coating of BSA and Ca-P on cpTi. The present study provides the possibility to achieve a long-term effective release of biologically active proteins from a Ca-P-coated metallic implant.

Biocomposites and hybrid biomaterials based on calcium orthophosphates

“…836 Biocomposites of CDHA with water-soluble proteins, such as BSA, might be prepared by a precipitation method. 561,[839][840][841][842] In such biocomposites, BSA is not strongly fixed to solid CDHA, which is useful for a sustained release. However, this is not the case if a water/oil/water interfacial reaction route has been used.…”

Calcium orthophosphate-based biocomposites and hybrid biomaterials

“…Biocomposites of CDHA with water-soluble proteins, such as bovine serum albumin (BSA), might be prepared by a precipitation method [463,[689][690][691][692]. In such biocomposites, BSA is not strongly fixed to solid CDHA, which is useful for a sustained release.…”

Advances in Biomimetic Apatite Coating on Metal Implants

“…Wen et al pretreated titanium by acid etching, boiling diluted alkali incubation, precalcification, and immersed it in SCS with or without containing BSA. Their results also showed that the incorporation of BSA significantly modified the morphology, composition, and crystallinity of the apatite coating (Wen et al, 1999). The release rate of Ca 2+ ions from these BSA-containing apatite layers was slower than from non-protein-containing ones within the bathing medium, which indicated that BSA bonded strongly to Ca 2+ ions within the crystal lattice.…”

“…By this technique, biologically active molecules can be coprecipitated with apatite crystals onto metal implants rather than being merely adsorbed on its surface(Y. Liu et al, 2001Liu et al, , 2003Liu et al, , 2006Wen et al, 1999). Therefore, the biomimetic apatite coating can be used as the carriers for biologically active molecules.…”