Physicochemical and Biological Evaluation of Chitosan-Coated Magnesium-Doped Hydroxyapatite Composite Layers Obtained by Vacuum Deposition

Abstract

In the present work, the effectiveness of vacuum deposition technique for obtaining composite thin films based on chitosan-coated magnesium-doped hydroxyapatite Ca10−xMgx(PO4)6 (OH)2 with xMg = 0.025 (MgHApCh) was proved for the first time. The prepared samples were exposed to three doses (0, 3, and 6 Gy) of gamma irradiation. The MgHApCh composite thin films nonirradiated and irradiated were evaluated by scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) studies. The biological evaluation of the samples was also presented. All the results obtained from this study showed that the vacuum deposition method allowed for obtaining uniform and homogeneous layers. Fine cracks were observed on the MgHApCh composite thin films’ surface after exposure to a 6 Gy irradiation dose. Additionally, after gamma irradiation, a decrease in Ca, P, and Mg content was noticed. The MgHApCh composite thin films with doses of 0 and 3 Gy of gamma irradiation showed a cellular viability similar to that of the control. Samples with 6 Gy doses of gamma irradiation did not cause significantly higher fibroblast cell death than the control (p > 0.05). On the other hand, the homogeneous distribution of pores that appeared on the surface of coatings after 6 Gy doses of gamma irradiation did not prevent the adhesion of fibroblast cells and their spread on the coatings. In conclusion, we could say that the thin films could be suitable both for use in bone implants and for other orthopedic and dentistry applications.

Impact of Gamma Irradiation on the Properties of Magnesium-Doped Hydroxyapatite in Chitosan Matrix

“…Furthermore, the surfaces of the studied samples did not show any other defects (e.g., cracks, etc.). Our results are in concordance with the results presented in previous studies reported in the literature [ 19 , 20 ].…”

“…All these peaks suggest the formation of a chitosan-coated magnesium-doped hydroxyapatite structure. Thus, the peak found at about 480 cm −1 belongs to ν 2 (PO 4 3− ), while the bands from 562, 602, and 633 cm −1 are attributed to ν 4 (PO 4 3− ) vibration [ 19 , 20 ]. The peak found at 962 cm −1 is specific to ν 1 (PO 4 3− ); meanwhile, the peaks observed at around 1028 and 1094 cm −1 belong to the ν 3 (PO 4 3− ) from the hydroxyapatite structure [ 19 , 20 ].…”

“…Thus, the peak found at about 480 cm −1 belongs to ν 2 (PO 4 3− ), while the bands from 562, 602, and 633 cm −1 are attributed to ν 4 (PO 4 3− ) vibration [ 19 , 20 ]. The peak found at 962 cm −1 is specific to ν 1 (PO 4 3− ); meanwhile, the peaks observed at around 1028 and 1094 cm −1 belong to the ν 3 (PO 4 3− ) from the hydroxyapatite structure [ 19 , 20 ]. The presence of chitosan in the studied samples was emphasized by the presence of the peaks in the 1300–1600 cm −1 spectral range.…”

“…The presence of chitosan in the studied samples was emphasized by the presence of the peaks in the 1300–1600 cm −1 spectral range. In the spectral range mentioned above, we observed the peaks that are characteristic of the C–H/N–H/C=O/C–O vibration from chitosan [ 20 ]. The broadened peak observed at ~1542 cm −1 could belong to ν (NH 2 ) from the chitosan structure [ 32 , 48 ].…”

“…Furthermore, in our previous studies we have reported valuable information regarding the influence of gamma irradiation on the physico-chemical and biological properties of magnesium-doped hydroxyapatite/chitosan composite thin films (x Mg = 0.025 and 0.1) developed by radiofrequency (RF) magnetron sputtering [ 19 ] and vacuum deposition [ 20 ] techniques. Our findings showed that the radiation dose and magnesium concentration (from the samples) play a crucial role in the final morphological, molecular, chemical compositional, and biological properties of the coatings [ 19 , 20 ].…”