by Keyword: brushes

Witzdam, L, Vosberg, B, Grosse-Berkenbusch, K, Stoppelkamp, S, Wendel, HP, Rodriguez-Emmenegger, C, (2024). Tackling the Root Cause of Surface-Induced Coagulation: Inhibition of FXII Activation to Mitigate Coagulation Propagation and Prevent Clotting Macromolecular Bioscience 24, e2300321

Factor XII (FXII) is a zymogen present in blood that tends to adsorb onto the surfaces of blood-contacting medical devices. Once adsorbed, it becomes activated, initiating a cascade of enzymatic reactions that lead to surface-induced coagulation. This process is characterized by multiple redundancies, making it extremely challenging to prevent clot formation and preserve the properties of the surface. In this study, a novel modulatory coating system based on C1-esterase inhibitor (C1INH) functionalized polymer brushes, which effectively regulates the activation of FXII is proposed. Using surface plasmon resonance it is demonstrated that this coating system effectively repels blood plasma proteins, including FXII, while exhibiting high activity against activated FXII and plasma kallikrein under physiological conditions. This unique property enables the modulation of FXII activation without interfering with the overall hemostasis process. Furthermore, through dynamic Chandler loop studies, it is shown that this coating significantly improves the hemocompatibility of polymeric surfaces commonly used in medical devices. By addressing the root cause of contact activation, the synergistic interplay between the antifouling polymer brushes and the modulatory C1INH is expected to lay the foundation to enhance the hemocompatibility of medical device surfaces.© 2023 The Authors. Macromolecular Bioscience published by Wiley-VCH GmbH.

JTD Keywords: adsorption, binding, c1-esterase-inhibitor, coatings, contact activation, factor-xii, fxii activation, hemocompatibility, hemocompatible surface modification, heparin, polymer brushes, system, thrombosis, Adsorption, Anticoagulation, Antifouling agent, Article, Beta-fxiia, Biocompatibility, Blood, Blood clotting, Blood clotting factor 12, Blood clotting factor 12a, Blood clotting factor 12a inhibitor, Blood coagulation, C1-esterase-inhibitor, Cell activation, Chemical activation, Coagulation, Coating (procedure), Complement component c1s inhibitor, Complement system, Controlled study, Dendrimers, Enzyme immobilization, Enzymes, Erythrocyte, Esters, Factor xii, Factor xii activation, Factor xiia, Fibrin deposition, Functional polymers, Fxii activation, Haemocompatibility, Hemocompatibility, Hemocompatible surface modification, Hemostasis, Heparin, Human, Hydrogel, Medical devices, Metabolism, Plasma kallikrein, Plasma protein, Plastic coatings, Platelet count, Polymer, Polymer brushes, Polymerization, Polymers, Property, Root cause, Surface plasmon resonance, Surface property, Surface reactions, Surface-modification, Thrombocyte adhesion, Β-fxiia

Englert, J, Witzdam, L, Söder, D, Garay-Sarmiento, M, Joseph, A, Wagner, AM, Rodriguez-Emmenegger, C, (2023). Synthetic Evolution of a Supramolecular Harpooning Mechanism to Immobilize Vesicles at Antifouling Interfaces Macromolecular Chemistry And Physics 224, 2300306

The immobilization of vesicles has been conceptualized as a method to functionalize biointerfaces. However, the preservation of their integrity post immobilization remains a considerable challenge. Interfacial interactions can cause vesicle rupture upon close surface contact and non-specific protein adsorption impairing surface functions. To date, immobilization of vesicles has relied solely on either entrapment or prior modification of vesicles, both of which require laborious preparation and limit their applications. This work develops a bioinspired strategy to pin vesicles without prior modification while preserving their intact shape. This work introduces antifouling diblock copolymers and ultrathin surface-attached hydrogels containing a brush-like interface consisting of a bottle brush copolymer of N-(2-hydroxypropyl) methacrylamide (HPMA) and N-(3-methacrylamidopropyl)-N,N-dimethyldodecan-1-aminiumiodide (C12+). The presence of positive charges generates an attractive force that pulls vesicles toward the surface. At the surface, the amphiphilic properties of the combs facilitate their insertion into the membrane, mimicking the harpooning mechanism observed in antimicrobial peptides. Importantly, the antifouling poly(HPMA) backdrop serves to safeguard the vesicles by preventing deformation and breakage. Using a combination of thermodynamic analysis, surface plasmon resonance, and confocal laser scanning microscopy, this work demonstrates the efficiency of this biomimetic system to capture vesicles while maintaining an antifouling interface necessary for bioapplications. This work presents a novel supramolecular approach that combines three key elements: long-range attraction, vesicle pinning, and short-range repulsion to attract and harpoon vesicles, while protecting them at the surface. This work envisions these coatings as universal and biocompatible platforms that can be used not only to study vesicle interactions, but also as tools for biomedical applications.image

JTD Keywords: Antifouling coatings, Coatings, Delivery, Extracellular vesicles, Fabrication, Hydrogel, Janus dendrimers, Lipid vesicles, Liposomes, Membrane insertion, Polymer brushes, Proteins, Surface-energy components, Ultrathin surface-attached hydrogels, Vesicle pinning

Witzdam, L, Garay-Sarmiento, M, Gagliardi, M, Meurer, YL, Rutsch, Y, Englert, J, Philipsen, S, Janem, A, Alsheghri, R, Jakob, F, Molin, DGM, Schwaneberg, U, van den Akker, NMS, Rodriguez-Emmenegger, C, (2023). Brush-Like Coatings Provide a Cloak of Invisibility to Titanium Implants Macromolecular Bioscience , e2300434

Orthopedic implants such as knee and hip implants are one of the most important types of medical devices. Currently, the surface of the most advanced implants consists of titanium or titanium-alloys with high porosity at the bone-contacting surface leading to superior mechanical properties, excellent biocompatibility, and the capability of inducing osseointegration. However, the increased surface area of porous titanium provides a nidus for bacteria colonization leading to implant-related infections, one of the main reasons for implant failure. Here, two readily applicable titanium-coatings based on hydrophilic carboxybetaine polymers that turn the surface stealth thereby preventing bacterial adhesion and colonization are developed. These coatings are biocompatible, do not affect cell functionality, exhibit great antifouling properties, and do not cause additional inflammation during the healing process. In this way, the coatings can prevent implant-related infections, while at the same time being completely innocuous to its biological environment. Thus, these coating strategies are a promising route to enhance the biocompatibility of orthopedic implants and have a high potential for clinical use, while being easy to implement in the implant manufacturing process.© 2023 The Authors. Macromolecular Bioscience published by Wiley-VCH GmbH.

JTD Keywords: bacteria repellency, biocompatibility, blood-plasma, brushes, stealth coatings, surface, titanium implants, Antifouling surfaces, Bacteria repellency, Biocompatibility, Brushes, Polymer brushes, Stealth coatings, Titanium implants

Quandt, J, Garay-Sarmiento, M, Witzdam, L, Englert, J, Rutsch, Y, Stöcker, C, Obstals, F, Grottke, O, Rodriguez-Emmenegger, C, (2022). Interactive Hemocompatible Nanocoating to Prevent SurfaceInduced Coagulation in Medical Devices Advanced Materials Interfaces 9, 2201055

Riedelová, Z, Pereira, AD, Svoboda, J, Pop-Georgievski, O, Májek, P, Pecánková, K, Dycka, F, Rodriguez-Emmenegger, C, Riedel, T, (2022). The Relation Between Protein Adsorption and Hemocompatibility of Antifouling Polymer Brushes Macromolecular Bioscience 22, 2200247

Whenever an artificial surface comes into contact with blood, proteins are rapidly adsorbed onto its surface. This phenomenon, termed fouling, is then followed by a series of undesired reactions involving activation of complement or the coagulation cascade and adhesion of leukocytes and platelets leading to thrombus formation. Thus, considerable efforts are directed towards the preparation of fouling-resistant surfaces with the best possible hemocompatibility. Herein, a comprehensive hemocompatibility study after heparinized blood contact with seven polymer brushes prepared by surface-initiated atom transfer radical polymerization is reported. The resistance to fouling is quantified and thrombus formation and deposition of blood cellular components on the coatings are analyzed. Moreover, identification of the remaining adsorbed proteins is performed via mass spectroscopy to elucidate their influence on the surface hemocompatibility. Compared with an unmodified glass surface, the grafting of polymer brushes minimizes the adhesion of platelets and leukocytes and prevents the thrombus formation. The fouling from undiluted blood plasma is reduced by up to 99%. Most of the identified proteins are connected with the initial events of foreign body reaction towards biomaterial (coagulation cascade proteins, complement component, and inflammatory proteins). In addition, several proteins that are not previously linked with blood-biomaterial interaction are presented and discussed.

JTD Keywords: antifouling surfaces, biosensor, blood-plasma, coagulation, coatings, compatibility, glycoprotein, hemocompatibility, identification, methacrylate), ms identification, polymer brushes, protein adsorption, surface-chemistry, Antifouling surfaces, High-density-lipoprotein, Protein adsorption

Yang, BQ, Wang, YX, Vorobii, M, Sauter, E, Koenig, M, Kumar, R, Rodriguez-Emmenegger, C, Hirtz, M, (2022). Evaluation of Dibenzocyclooctyne and Bicyclononyne Click Reaction on Azido-Functionalized Antifouling Polymer Brushes via Microspotting Advanced Materials Interfaces 9, 2102325

Benetti, E., Navarro, M., Zapotoczny, S., Vancso, G. J., (2009). Stimuli-Responsive Polymer Brushes Surface Design: Applications in Bioscience and Nanotechnology (ed. Förch, R. , Schönherr, H. , Jenkins, A.T.A), Wiley-VCH GmbH & Co. KGaA (Weinheim, Germany) , 125-144