The development of a facile and versatile strategy to endow surfaces with synergistically anti-inflammatory, antimicrobial, and anticoagulant functions is of particular significance for blood-contacting biomaterials and medical devices. In this work, we report a simple and environmentally friendly "one-pot" method inspired by byssal cuticle chemistry, namely, [Fe(dopa) 3 ] coordination chemistry for assembly of copper ions (Cu 2+ ) and plant polyphenol (tannic acid)/ catecholamine (dopamine or norepinephrine) to form metal− phenolic/catecholamine network-based coatings. This one-pot method enabled us to easily develop a multifunctional surface based on the combination of the characteristic functions of metal ions and plant polyphenol or catecholamine. The residual phenolic hydroxyl groups on the coatings imparted the modified surface with excellent antioxidant and anti-inflammatory functions. The robust chelation of copper ions to the metal− phenolic/catecholamine networks provided not only durable antibacterial property but also glutathione peroxidase like catalytic capability to continuously and controllably produce antithrombotic nitric oxide by catalyzing endogenous S-nitrothiol. The biological functions of such coatings could be well regulated by adjusting the ratios of the feed concentration of Cu 2+ ions to plant polyphenol or catecholamine. We envision that our simple, multifunctional, and bioinspired coating strategy can hold great application promise for bioengineering blood-contacting devices.

Enhancement mechanism of the hydrogen evolution reaction (HER) attributed to the synergistic effect of electron-traps and surface plasmon resonance (SPR).

Stenting is currently the major therapeutic treatment for cardiovascular diseases. However, the nonbiogenic metal stents are inclined to trigger a cascade of cellular and molecular events including inflammatory response, thrombogenic reactions, smooth muscle cell hyperproliferation accompanied by the delayed arterial healing, and poor reendothelialization, thus leading to restenosis along with late stent thrombosis. To address prevalence critical problems, we present an endothelium-mimicking coating capable of rapid regeneration of a competently functioning new endothelial layer on stents through a stepwise metal (copper)-catechol-(amine) (MCA) surface chemistry strategy, leading to combinatorial endothelium-like functions with glutathione peroxidase-like catalytic activity and surface heparinization. Apart from the stable nitric oxide (NO) generating rate at the physiological level (2.2×10−10 mol/cm2/min lasting for 60 days), this proposed strategy could also generate abundant amine groups for allowing a high heparin conjugation efficacy up to ∼1 μg/cm2, which is considerably higher than most of the conventional heparinized surfaces. The resultant coating could create an ideal microenvironment for bringing in enhanced anti-thrombogenicity, anti-inflammation, anti-proliferation of smooth muscle cells, re-endothelialization by regulating relevant gene expressions, hence preventing restenosis in vivo. We envision that the stepwise MCA coating strategy would facilitate the surface endothelium-mimicking engineering of vascular stents and be therefore helpful in the clinic to reduce complications associated with stenosis.

Thanks to its simplicity, versatility, and secondary reactivity, dopamine self-polymerized coatings (pDA) have been widely used in surface modification of biomaterials, but the limitation in secondary molecular grafting and the high roughness restrain their application in some special scenarios. Therefore, some other catecholamine coatings analog to pDA have attracted more and more attention, including the smoother poly-norepinephrine coating (pNE), and the poly-levodopa coating (pLD) containing additional carboxyl groups. However, the lack of a systematic comparison of the properties, especially the biological properties of the above three catecholamine coatings, makes it difficult to give a guiding opinion on the application scenarios of different coatings. Herein, we systematically studied the physical, chemical, and biological properties of the three catecholamine coatings, and explored the feasibility of their application for the modification of biomaterials, especially cardiovascular materials. Among them, the pDA coating was the roughest, with the largest amount of amino and phenolic hydroxyl groups for molecule grafting, and induced the strongest platelet adhesion and activation. The pLD coating was the thinnest and most hydrophilic but triggered the strongest inflammatory response. The pNE coating was the smoothest, with the best hemocompatibility and histocompatibility, and with the strongest cell selectivity of promoting the proliferation of endothelial cells while inhibiting the proliferation of smooth muscle cells. To sum up, the pNE coating may be a better choice for the surface modification of cardiovascular materials, especially those for vascular stents and grafts, but it is still not widely recognized.

The unique advantages of nitric oxide (NO) in cardiovascular disease therapy have driven the development of methods to functionalize cardiovascular stents for local generation of NO. However, current NO-generating materials used for surface engineering stents have limitations such as a complex fabrication process, poor stent adhesion strength, and low control of NO release. Herein, we apply synergetic coordination and catecholamine surface chemistry to develop an adhesive NO-generating coating with a copper-catecholamine framework through a simple, one-step molecule/ion co-assembly process. The copper-catecholic-selenocystamine framework provides glutathione peroxidase (GPx)-like interfacial catalytic activity, which results in long-term, stable, adjustable NO release rates from the coating. The resulting desirable therapeutic dose and release kinetics of NO endow the vascular stent with the ability to simultaneously inhibit platelet activation and smooth muscle cell (SMC) proliferation, and enhances endothelial cell (EC) adhesion, proliferation, and migration in vitro. Vascular stent functionalized by the optimized copper-catecholic-selenocystamine coating significantly suppresses thrombosis, promotes re-endothelialization, and reduces intimal hyperplasia in vivo, and may be promising to address the clinical complications associated with restenosis and late stent thrombosis.