Mimicking Mytilus edulis foot protein:A versatile strategy for robust biomedical coatings

Universal coatings with versatile surface adhesion,good mechanochemical robustness,and the capacity for secondary modification are of great scientific interest.However,incorporating these advantages into a system is still a great challenge.Here,we report a series of catechol-decorated polyallylamines(CPAs),denoted as pseudo-Mytilus edulis foot protein 5(pseudoMefp-5),that mimic not only the catechol and amine groups but also the backbone of Mefp-5.CPAs can fabricate highly adhesive,robust,multifunctional polyCPA(PCPA)coatings based on synergetic catechol-polyamine chemistry as universal building blocks.Due to the interpenetrating entangled network architectures,these coatings exhibit high chemical robustness against harsh conditions(HCl,pH 1;NaOH,pH 14;H2O2,30%),good mechanical robustness,and wear resistance.In addition,PCPA coatings provide abundant grafting sites,enabling the fabrication of various functional surfaces through secondary modification.Furthermore,the versatility,multifaceted robustness,and scalability of PCPA coatings indicate their great potential for surface engineering,especially for withstanding harsh conditions in multipurpose biomedical applications.

Endothelium-Mimicking Multifunctional Coating Modified Cardiovascular Stents via a Stepwise Metal-Catechol-(Amine)Surface Engineering Strategy

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/cm^(2)/min lasting for 60 days),this proposed strategy could also generate abundant amine groups for allowing a high heparin conjugation efficacy up to∼1μg/cm^(2),which is considerably higher than most of the conventional heparinized surfaces.The resultant coating could create an ideal microenvironment for bringing in enhanced antithrombogenicity,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.

A Versatile Surface Bioengineering Strategy Based on Mussel-Inspired and Bioclickable Peptide Mimic

In this work,we present a versatile surface engineering strategy by the combination of mussel adhesive peptide mimicking and bioorthogonal click chemistry.The main idea reflected in this work derived from a novel mussel-inspired peptide mimic with a bioclickable azide group(i.e.,DOPA_(4)-azide).Similar to the adhesion mechanism of the mussel foot protein(i.e.,covalent/noncovalent comediated surface adhesion),the bioinspired and bioclickable peptide mimic DOPA_(4)-azide enables stable binding on a broad range of materials,such as metallic,inorganic,and organic polymer substrates.In addition to the material universality,the azide residues of DOPA_(4)-azide are also capable of a specific conjugation of dibenzylcyclooctyne-(DBCO-)modified bioactive ligands through bioorthogonal click reaction in a second step.To demonstrate the applicability of this strategy for diversified biofunctionalization,we bioorthogonally conjugated several typical bioactive molecules with DBCO functionalization on different substrates to fabricate functional surfaces which fulfil essential requirements of biomedically used implants.For instance,antibiofouling,antibacterial,and antithrombogenic properties could be easily applied to the relevant biomaterial surfaces,by grafting antifouling polymer,antibacterial peptide,and NO-generating catalyst,respectively.Overall,the novel surface bioengineering strategy has shown broad applicability for both the types of substrate materials and the expected biofunctionalities.Conceivably,the“clean”molecular modification of bioorthogonal chemistry and the universality of mussel-inspired surface adhesion may synergically provide a versatile surface bioengineering strategy for a wide range of biomedical materials.

Intelligent H_(2)S release coating for regulating vascular remodeling

Coronary atherosclerotic lesions exhibit a low-pH chronic inflammatory response.Due to insufficient drug release control,drug-eluting stent intervention can lead to delayed endothelialization,advanced thrombosis,and unprecise treatment.In this study,hyaluronic acid and chitosan were used to prepare pH-responsive self-assembling films.The hydrogen sulfide(H2S)releasing aspirin derivative ACS14 was used as drug in the film.The film regulates the release of the drug adjusted to the microenvironment of the lesion,and the drug balances the vascular function by releasing the regulating gas H2S,which comparably to NO promotes the self-healing capacity of blood vessels.Drug releasing profiles of the films at different pH,and other biological effects on blood vessels were evaluated through blood compatibility,cellular,and implantation experiments.This novel method of self-assembled films which H2S in an amount,which is adjusted to the condition of the lesion provides a new concept for the treatment of cardiovascular diseases.