Magnesium (Mg)-based bioresorbable cardiovascular scaffold (BCS) is a promising alternative to conventional permanent cardiovascular stents, but it faces the challenges of rapid degradation and poor endothelium recovery after device degradation. To address these challenges, we investigated poly(Llactic acid) (PLLA), poly(lactic-co-glycolic acid) (PLGA) (90:10), PLGA (50:50), and polycaprolactone (PCL) coatings on Mg, respectively, and evaluated their surface and biological properties. Intact polymer coatings with complete coverage on Mg substrate were achieved. The biological performance of the materials was evaluated by culturing with human umbilical vein endothelial cells (HUVECs) in vitro using the direct culture method. The pH of the culture media and Mg 2+ and Ca 2+ ion concentrations in the media were measured after culture to characterize the degradation rate of the materials in vitro. The results showed that the PLGA (50:50) coating improved the adhesion and spreading of HUVECs the most among the four polymer coatings. Moreover, we found three possible factors that promoted HUVECs directly attached on the surface of PLGA (50:50)coated Mg: (1) the higher concentration of Mg 2+ ions released into culture media with a concentration range of 9−15 mM; (2) the lower Ca 2+ ion concentration in culture media at 1.3−1.6 mM; and (3) the favorable surface conditions of PLGA (50:50), when compared with the other sample groups. This in vitro study provided the first evidence that the PLGA (50:50) is a promising coating material for Mg-based biodegradable metals toward potential cardiovascular or neurovascular applications.

Nanomaterials such as nanostructured surfaces, nanoparticles, and nanocomposites represent new viable sources for future therapeutics for cardiovascular diseases. The special properties of nanomaterials such as their intrinsic physiochemical properties, surface energy and surface topographies could actively enhance desirable cellular responses within the cardiovascular system, projecting a growing potential for clinical translation. Recent progress on nanomaterials opened up new opportunities for treating cardiovascular diseases. Successful translation of nanomaterials into cardiovascular applications requires a comprehensive understanding of both nanomaterials and biomedicine, and, thus, it is critical to stress current advancements on both sides. In this review, the authors introduced crucial fabrication techniques for promising nanomaterials for cardiovascular applications. This review highlighted the key elements to consider for their fabrication, properties and applications. The important concerns relevant to cardiovascular nanomaterials, such as cellular responses to nanomaterials and the toxicity of nanomaterials, are also discussed. This review provided an overview of necessary knowledge and key concerns on nanomaterials specific for treating cardiovascular diseases, from the perspectives of both material science and biomedicine.

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Magnesium (Mg) alloys are promising materials for biodegradable implants, but their clinical translation requires improved control over their degradation rates. Proteins may be a major contributing factor to Mg alloy degradation, but are not yet fully understood. This article reports the effects of fetal bovine serum (FBS), a physiologically relevant mixture of proteins, on Mg and Mg alloy degradation. FBS had little impact on mass loss of pure Mg during immersion degradation, regardless of whether or not a native oxide layer was present on the sample surface. FBS reduced the mass loss of Mg-Yttrium (MgY) alloy with an oxidized surface during immersion degradation, but increased the mass loss for the same alloy with a metallic surface (surface oxides were removed). FBS also influenced the mode of degradation by limiting the depth of pit formation during degradation processes on commercially pure Mg with metallic or oxidized surfaces and on MgY alloy with oxidized surfaces. The results demonstrated that serum proteins had significant interactions with Mg-based biodegradable metals, and these interactions may be modified by alloy composition and processing. Therefore, proteins should be taken into account when designing experiments to assess degradation of Mg-based implants.

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