Enhanced Anti-corrosion Ability and Biocompatibility of PLGA Coatings on MgZnYNd Alloy by BTSE-APTES Pre-treatment for Cardiovascular Stent

• Published in: Journal of materials science & technology Vol. 32; no. 9; pp. 845 - 857
• Main Authors: Liu, Jing, Xi, Tingfei
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2016
• Subjects: Anti-corrosion; Biocompatibility; Cardiovascular stent; Coatings; Corrosion prevention; Corrosion resistance; Cytocompatibility; Infrared spectroscopy; MgZnYNd alloy; PLGA; Pretreatment; Scanning electron microscopy; Silanization; Surgical implants; 人脐静脉内皮细胞; 合金涂层; 抗腐蚀能力; 生物相容性; 血管支架; 镁合金; 预处理; Anti-corrosion; Silanization; Cytocompatibility; Cardiovascular stent; MgZnYNd alloy
• ISSN: 1005-0302; 1941-1162
• DOI: 10.1016/j.jmst.2016.06.021

Bioabsorbable magnesium alloys are widely studied for various implant applications, as they reduce the risks such as severe inflammatory response existing in permanent metallic implants. However, the over-fast corrosion rate of magnesium alloy is usually an obstacle in biomedical applications. Here we report a simple two-step reaction to introduce anticorrosive silane pre-treatment on MgZnYNd alloys before coating with poly （glycolide-co-lactide） （PLGA）. The first step is to immerse the NaOH-activated MgZnYNd with bistriethoxysilylethane （BTSE） to form a cross-linked silane coating layer with enhanced corrosion resistance; the second step involves immobilizing amine functional groups for forming hydrogen bond with outer PLGA coating by treating the BTSE-modified MgZnYNd with 3-amino-propyltrimethoxysilane （APTES）. We characterized the BTSE-APTES pre-treated PLGA coating on MgZnYNd by scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy （FF-IR）, X-ray photoelectron spectroscopy （XPS）, static contact angle and Acid Orange 7 measurement. Nano-scratch test was to verify that the scratch resistance of the PLGA coating with BTSE-APTES pre-treatment was superior to direct PLGA coating. Stan-dard electrochemical measurements along with the long-term immersion results indicated that the BTSE- APTES pre-treatment rendered better in vitro degradation behavior. Cell adhesion and cell viability tests with both vascular smooth muscle cells （VSMC） and human umbilical vein endothelial cells （EA. hy926） demonstrated that BTSE-APTES pre-treated MgZnYNd substrate had significantly more beneficial effects. The favorable anti-corrosion behavior and biocompatibility of BTSE-APTES pre-treated PLGA coatings on MgZnYNd alloy suggest that the novel two-step silanization procedure may have the great potential to enhance the performance of the magnesium-based biomaterials and provide a valid solution for the conversion modification of cardiovascular implants, taking the magnesium-based bioabsorbable materials closer to clinical application.