Needle-less electrospinning employed for calcium and magnesium phosphate coatings on titanium substrates

Abstract

The needle-less electrospinning method was employed for a preparation of calcium phosphate (CP) and magnesium calcium phosphate (MgCP) fibers as biocompatible coatings on Ti substrate. The polyvinylalcohol, triethyl phosphite, calcium and magnesium nitrates were used for a preparation of spun solutions and subsequent precursor fiber formation. The citric acid of 10 wt% was added to the spun solution in order to increase conductivity as well as a convenient complexing agent. A possible mechanism of complexation process of triethyl phosphite with calcium and magnesium nitrates with citric acid is presented. The optimization of calcination temperatures was defined according to the results obtained from TG/DSC analysis. The XRD analysis confirmed the formation of hydroxyapatite and Mg-whitlockite phases at both used temperatures 600 and 800 °C. The final morphology and thickness of prepared CP and MgCP fibrous coatings was designed by a suitable choice of the used sols, spinning time and calcination temperature. The SEM/FIB observations revealed that the average thickness of the CP coating was around 1 μm, which is almost two times thinner than the MgCP coating with the approximate width 2 μm. The in vitro cytotoxicity tests of the substrate surfaces revealed that the osteoblastic MC3T3-E1 cells have a good proliferation activity when cultured on the 600°C calcined substrates covered by smooth and uniform fibrous nets. A strong cytotoxic cell response was observed in the samples treated at 800°C, where the fibrous coatings were disrupted by the newly formed sharp rutile (TiO 2 ) micro-crystals. Such surface topography acts against the initial adhesion and proliferation of osteoblast like cells.

Nitrate‐Free Synthesis and Electrospinning of Carbonated Hydroxyapatite Coatings on TA6V Implants

“…Both its chemical composition and submicrometer fibrous topography can play a role in this improved biocompatibility. These results are promising, especially because in comparison, the metabolic activity of MC3T3‐E1 cells (after 2–10 days of culture) was reduced on the fibrous coatings of hydroxyapatite developed by Streckova et al [ 38 ] compared to the control TA6V substrate. Note that these CaP electrospun coatings are the only ones reported in the literature so far, to the author's knowledge, and they are nitrate‐derived.…”

Biodegradable magnesium phosphates in biomedical applications

“…Pure magnesium phosphate coatings Thanks to their outstanding biocompatibility and biodegradability, MgPs coatings are often constructed on implants to increase the osteogenesis capability and corrosion resistance of metal implants. [138][139][140][141][142][143] Zai and colleagues compared the corrosion resistance and biocompatibility of MgP, zinc phosphate (ZnP) and CaP conversion coatings on an Mg alloy, and the results indicated that the order of conversion coating generation priority was ZnP 4 CaP 4 MgP; the order of compactness was MgP 4 CaP 4 ZnP; the order of long-term corrosion resistance was ZnP 4 CaP 4 MgP; and the CaP coatings exhibited better biocompatibility than ZnP and MgP coatings as well as bare Mg alloy substrates. 144 Zaffora et al verified that MgP coatings that had grown on the AZ31 Mg alloy by a hard anodizing process were biocompatible and could enhance the corrosion resistance of the AZ31 Mg alloy.…”

Regulation of Magnesium Matrix Composites Materials on Bone Immune Microenvironment and Osteogenic Mechanism

“…Calcium (Ca) is a major component of bone, and Ca ions are also necessary for each cell they regulate various biochemical reactions in vivo , such as in the absence of serum in culture medium, and the addition of Ca ions can enhance the proliferation of stem cells and induce osteogenic differentiation ( MarmionCeline et al, 2014 ; Lei et al, 2015 ). Multiple in vitro studies have also reported the enhancing effects of Mg or Ca on osteoblast activity, such as improving cell growth status and alkaline phosphatase (ALP) expression ( Streckova et al, 2018 ).…”