Engineering Triphasic Nanocomposite Coatings on Pretreated Mg Substrates for Biomedical Applications

Area of Science:

• Biomaterials Science
• Nanotechnology
• Surface Engineering

Background:

• Magnesium (Mg) alloys are promising for biodegradable implants but require surface modifications for enhanced performance.
• Biodegradable poly(glycerol sebacate) (PGS) is a suitable polymer matrix for biomedical applications.
• Nanocomposite coatings can improve the corrosion resistance and cytocompatibility of Mg alloys.

Purpose of the Study:

• To synthesize and develop a novel PGS nanocomposite coating incorporating hydroxyapatite (HA) and magnesium oxide (MgO) nanoparticles.
• To evaluate the effect of alkaline pretreatment on Mg substrates and the PGS/nHA/nMgO nanocomposite coating on interfacial adhesion.
• To assess the cytocompatibility of the developed coating with bone marrow derived mesenchymal stem cells (BMSCs).

Main Methods:

• Synthesis of a poly(glycerol sebacate) (PGS) nanocomposite system with hydroxyapatite (HA) and magnesium oxide (MgO) nanoparticles.
• Alkaline pretreatment of magnesium (Mg) substrates to enhance interfacial adhesion.
• Development of a spray coating process to apply the PGS/nHA/nMgO nanocomposite layer onto Mg substrates.
• Evaluation of BMSC adhesion densities on coated and uncoated Mg substrates under direct contact conditions.

Main Results:

• Alkaline pretreatment and the addition of nHA and nMgO nanoparticles significantly enhanced interfacial adhesion strength compared to PGS coatings on untreated Mg.
• The PGS/nHA/nMgO coated Mg substrates showed higher average BMSC adhesion densities than non-coated Mg controls.
• The nanocomposite coating on Mg substrates demonstrated superior BMSC adhesion compared to coated titanium and PGS-coated Mg controls.

Conclusions:

• The spray coating of PGS/nHA/nMgO nanocomposites on pretreated Mg substrates is a promising surface treatment strategy for biodegradable implants.
• The developed coating enhances both interfacial adhesion and cytocompatibility, crucial for biomedical applications.
• This approach offers a viable method to improve the performance of biodegradable metal substrates in medical devices.