Fabrication of Citric Acid/RGD Multilayers on Mg‐Zn‐Y‐Nd Alloy via Layer‐by‐Layer Self‐Assembly for Promoting Surface Biocompatibility

Abstract

Magnesium (Mg) alloy, an important biodegradable material widely investigated on cardiovascular stent, is restricted for further application due to some limited functions, such as the excessively rapid degradation rate, poor hemocompatibility, and delayed re‐endothelialization. To overcome these shortcomings, surface modification with biomolecules has attracted much attention. In this study, the multifunctional coatings of citric acid (CA) and Arg‐Gly‐Asp (RGD) via layer‐by‐layer self‐assembly are immobilized onto the polydopamine (PDA) deposited surface which is passivated with hydrofluoric acid (HF) solution before. The basic characterization results suggest that PDA/(CA‐RGD)2 coating exhibits a rich‐in‐amine and hydrophilic surface. The corrosion current density of PDA/(CA‐RGD)2 exposed to simulated body fluid is reduced by 95.65% from 1.586 × 10−4 to 6.894 × 10−6 A cm−2 under the protection of the dense MgF2 layer and multifunctional coatings. Besides, inhibition on platelet adhesion, hemolysis rates, and fibrinogen adsorption also prove the enhanced hemocompatibility of the PDA/(CA‐RGD)2 coatings. Meanwhile, the human umbilical vein endothelial cells (HUVECs) and smooth muscle cells (SMCs) culture results jointly prove the excellent endothelialization performance of functionalized samples. In conclusion, the above mentioned results reveal that the functionalized surface of PDA/(CA‐RGD)2 displays better overall performance, indicating a preferable application for cardiovascular stents.

Tailoring ZE21B Alloy with Nature-Inspired Extracellular Matrix Secreted by Micro-Patterned Smooth Muscle Cells and Endothelial Cells to Promote Surface Biocompatibility

“…After the washing step, the samples were dehydrated gradually using 25%, 50%, 75%, and 100% ethanol solution. During a complete drying step and spraying gold treatment, the platelets adherent on the samples were observed by SEM; the numbers of the platelets adherent on each sample were counted according to the previous report [ 48 ].…”

Citric Acid: A Multifunctional Pharmaceutical Excipient

“…Specifically, the biodegradable alloy of Mg-Zn-Y-Nd was coated with successive layers of polydopamine, citric acid, and Arg-Gly-Asp (RGD) peptide. The surface that was created is hemocompatible and allows for endothelization, while inhibiting smooth muscle cell adhesion and proliferation, overall improving the biocompatibility of the Mg alloy stents [ 105 , 106 ]. Extensive reviews of the role of citric acid as a crosslinker can be found in references [ 107 , 108 ].…”

Endothelialization strategy of implant materials surface: The newest research in recent 5 years

“…Therefore, in the use of RGD modification, in addition to considering the conformation and density of RGD peptide, combined with anticoagulant substances is also a factor to be considered. 116 Layer-by-layer self-assembly 115 REDV Specifically bind to integrin α4β1 on the ECs. 117 Covalent grafting [118][119][120] 1.…”