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Biomagnetic of Apatite-Coated Cobalt Ferrite: A Core – Shell Particle for Protein Adsorption and pH-Controlled Release

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ABSTRACT

Magnetic nanoparticle composite with a cobalt ferrite (CoFe2O4, (CF)) core and an apatite (Ap) coating was synthesized using a biomineralization process in which a modified simulated body fluid (1.5SBF) solution is the source of the calcium phosphate for the apatite formation. The core–shell structure formed after the citric acid–stabilized cobalt ferrite (CFCA) particles were incubated in the 1.5 SBF solution for 1 week. The mean particle size of CFCA-Ap is about 750 nm. A saturation magnetization of 15.56 emug-1 and a coercivity of 1808.5 Oe were observed for the CFCA-Ap obtained. Bovine serum albumin (BSA) was used as the model protein to study the adsorption and release of the proteins by the CFCA-Ap particles. The protein adsorption by the CFCA-Ap particles followed a more typical Freundlich than Langmuir adsorption isotherm. The BSA release as a function of time became less rapid as the CFCA-Ap particles were immersed in higher pH solution, thus indicating that the BSA release is dependent on the local pH.

No MeSH data available.


FTIR spectra of pure BSA protein (left), and comparison of BSA protein loading onto the apatite (Ap)-coated citric acid–stabilized cobalt ferrite (CFCA) (CFCA-Ap) surface (right) at various concentrations: (a) 0.2 mg/ml, (b) 0.4 mg/ml, (c) 0.6 mg/ml, (d) 0.8 mg/ml, and (e) 1.0 mg/ml.
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Figure 6: FTIR spectra of pure BSA protein (left), and comparison of BSA protein loading onto the apatite (Ap)-coated citric acid–stabilized cobalt ferrite (CFCA) (CFCA-Ap) surface (right) at various concentrations: (a) 0.2 mg/ml, (b) 0.4 mg/ml, (c) 0.6 mg/ml, (d) 0.8 mg/ml, and (e) 1.0 mg/ml.

Mentions: The adsorption of BSA protein by the CFCA-Ap particles is seen in the FT-IR spectrums Figure 6. The IR spectra of pure BSA and of the BSA-loaded CFCA-Ap powders are shown together for comparison. The peaks in the FT-IR spectra of the pure BSA at 1,654 cm-1 are due to the C=O stretching mode of amide I; the peak at 1,540 cm-1, to the N–H bending mode of amide II and the peak at 1,384 cm-1 are due to the C–N stretching mode [39]. The FT-IR spectra of the 0.2–1.0 mg/ml BSA-loaded CFCA-Ap exhibit in addition to the characteristic adsorption bands of apatite, intense bands at 1,088 cm-1, at 1,035 cm-1 and at 961 cm-1. These bands are due to the (PO43-) stretching modes. The doublet at 602 and 562 cm-1 is due to the (PO43-) bending mode. The absorption peaks occurring at around 1,654 cm-1 and the weak intensity band at 1,540 cm-1 are due to the C=O bond in amide I and the C–H bond in amide II. The fact that there is no obvious changes occurring in the FT-IR spectrum of the CFCA-Ap groups and the presence of the absorption peaks of the BSA in the FT-IR spectrums of the BSA-loaded CFCA-Ap suggests that the BSA adsorption on the CFCA-Ap is a physical adsorption process.


Biomagnetic of Apatite-Coated Cobalt Ferrite: A Core – Shell Particle for Protein Adsorption and pH-Controlled Release
FTIR spectra of pure BSA protein (left), and comparison of BSA protein loading onto the apatite (Ap)-coated citric acid–stabilized cobalt ferrite (CFCA) (CFCA-Ap) surface (right) at various concentrations: (a) 0.2 mg/ml, (b) 0.4 mg/ml, (c) 0.6 mg/ml, (d) 0.8 mg/ml, and (e) 1.0 mg/ml.
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Related In: Results  -  Collection

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Figure 6: FTIR spectra of pure BSA protein (left), and comparison of BSA protein loading onto the apatite (Ap)-coated citric acid–stabilized cobalt ferrite (CFCA) (CFCA-Ap) surface (right) at various concentrations: (a) 0.2 mg/ml, (b) 0.4 mg/ml, (c) 0.6 mg/ml, (d) 0.8 mg/ml, and (e) 1.0 mg/ml.
Mentions: The adsorption of BSA protein by the CFCA-Ap particles is seen in the FT-IR spectrums Figure 6. The IR spectra of pure BSA and of the BSA-loaded CFCA-Ap powders are shown together for comparison. The peaks in the FT-IR spectra of the pure BSA at 1,654 cm-1 are due to the C=O stretching mode of amide I; the peak at 1,540 cm-1, to the N–H bending mode of amide II and the peak at 1,384 cm-1 are due to the C–N stretching mode [39]. The FT-IR spectra of the 0.2–1.0 mg/ml BSA-loaded CFCA-Ap exhibit in addition to the characteristic adsorption bands of apatite, intense bands at 1,088 cm-1, at 1,035 cm-1 and at 961 cm-1. These bands are due to the (PO43-) stretching modes. The doublet at 602 and 562 cm-1 is due to the (PO43-) bending mode. The absorption peaks occurring at around 1,654 cm-1 and the weak intensity band at 1,540 cm-1 are due to the C=O bond in amide I and the C–H bond in amide II. The fact that there is no obvious changes occurring in the FT-IR spectrum of the CFCA-Ap groups and the presence of the absorption peaks of the BSA in the FT-IR spectrums of the BSA-loaded CFCA-Ap suggests that the BSA adsorption on the CFCA-Ap is a physical adsorption process.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Magnetic nanoparticle composite with a cobalt ferrite (CoFe2O4, (CF)) core and an apatite (Ap) coating was synthesized using a biomineralization process in which a modified simulated body fluid (1.5SBF) solution is the source of the calcium phosphate for the apatite formation. The core–shell structure formed after the citric acid–stabilized cobalt ferrite (CFCA) particles were incubated in the 1.5 SBF solution for 1 week. The mean particle size of CFCA-Ap is about 750 nm. A saturation magnetization of 15.56 emug-1 and a coercivity of 1808.5 Oe were observed for the CFCA-Ap obtained. Bovine serum albumin (BSA) was used as the model protein to study the adsorption and release of the proteins by the CFCA-Ap particles. The protein adsorption by the CFCA-Ap particles followed a more typical Freundlich than Langmuir adsorption isotherm. The BSA release as a function of time became less rapid as the CFCA-Ap particles were immersed in higher pH solution, thus indicating that the BSA release is dependent on the local pH.

No MeSH data available.