engleski

The kinetics of bovine serum albumin adsorption onto CaP/TiO2 nanocomposites

The constantly growing need for improved bone regeneration materials motivates the research and development of novel biomaterials [1]. Thus, nanocomposites based on calcium phosphates (CaPs) and TiO2 nanomaterials (TiNMs) attract special attention as they combine good bioactivity of CaPs and good mechanical properties of TiNMs [2, 3]. Among key factors determining the fate of bioimplants in vivo are their interactions with blood serum proteins which adsorb at the surface of the implants immediately upon implantation. Depending on how proteins are adsorbed, the implant can either be successfully integrated or rejected/encapsulated [4]. The most abundant soluble protein that interacts with implants is albumin. The aim of this work was to systematically investigate the adsorption kinetics of bovine serum albumin (BSA) on TiNMs and their composites with CaPs. TiNM materials of different morphology and composition (nanoparticles (TiNP), nanotubes (TiNT), nanowires (TiNW), and nanoplates (TiNPl)) were synthesized by the hydrothermal method. Nanocomposites of CaPs and TiNMs (CaP/TiNMs), and calcium deficient hydroxyapatite (CaDHA) were synthesized by precipitation at conditions close to physiological [5, 6]. The TiNMs and CaP/TiNMs were characterized before and after adsorption by Fourier-transform infrared spectroscopy (FTIR), powder X-Ray diffraction (PXRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The kinetics of BSA adsorption onto TiNMs and CaP/TiNMs was determined by UV-VIS measurements at 37 °C for 24 h. The non-linear forms of pseudo-first (PFO), pseudo-second reaction order models, as well as Weber and Morris intraparticle diffusion model, were used to fit the obtained data and to evaluate the performance of the adsorbent and investigate the adsorption mass transfer mechanism [7]. The kinetic data were best fitted by the PSO model for all materials. Also, for CaDHA, CaP/TiNT, and CaP/TiNW kinetics of adsorption is controlled by the intraparticle diffusion process. The adsorption capacity was higher for nanocomposites compared to nanomaterials, while the rate of adsorption was lower. The obtained results represent a comparable set of data that can be used in the design of novel biomaterials for predicting their behaviour in vivo.

calcium phosphates ; TiO2 nanomaterials ; kinetics of adsorption

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