Implantation Of Medical Devices Research Articles

Actionability and familial uptake following opportunistic genomic screening in a pediatric cancer cohort.

The care for patients with serious conditions is increasingly guided by genomic medicine, and genomic medicine may equally transform care for healthy individual if genomic population screening is implemented. This study examines the medical impact of opportunistic genomic screening (OGS) in a cohort of patients undergoing comprehensive genomic germline DNA testing for childhood cancer, including the impact on their relatives. Medical actionability and uptake after cascade testing in the period following disclosure of OGS results was quantified. A secondary finding was reported to 19/595 (3.2%) probands primarily in genes related to cardiovascular and lipid disorders. After a mean follow up time of 1.6 years (Interquartile range (IQR): 0.57-1.92 yrs.) only 12 (63%) of these variants were found to be medically actionable. Clinical follow up or treatment was planned in 16 relatives, and as in the probands, the prescribed treatment was primarily betablockers or cholesterol lowering therapy. No invasive procedures or implantation of medical devices were performed in probands or relatives, and no reproductive counseling was requested. After an average of 1.6 years of follow-up 2.25 relatives per family with an actionable finding had been tested. This real-world experience of OGS grants new insight into the practical implementation effects and derived health care demands of genotype-first screening. The resulting health care effect and impact on demand for genetic counseling and workup in relatives extends beyond the effect in the probands.

Mir-146a is required for foreign body response and giant cell formation

The implantation of biomaterials or medical devices often leads to the development of a foreign body response (FBR), an inflammatory condition that can lead to implant failure, which may cause harm to or death of the patient. Hallmarks of the FBR include accumulation of macrophages and destructive foreign body giant cells (FBGCs), and development of fibrous scar tissue encompassing the implant. There are no effective medical treatments for FBR, although improved fundamental understanding of the molecular mechanisms underlying the development of FBR may lead to novel strategies for the amelioration of FBR. MicroRNAs (miRs) are endogenous, small, non-coding RNAs that have emerged as powerful regulators of gene expression in numerous cellular processes including macrophage activation, inflammation, and fibrosis. In this research, we tested the hypothesis that specific miRs play a crucial role in regulating the FBR to biomaterials. In our subcutaneous implantation mouse model, we found that: 1) miR-146a expression levels decreased in the implant-adhered tissues, and the decrease correlated with increased macrophage accumulation, FBGC formation, and collagen accumulation; and 2) miR-146a deletion in mice exacerbated in vivo macrophage accumulation, FBGC formation, and collagen accumulation. In our in vitro model, we found that deficiency of miR-146a function exacerbated key macrophage functions including adhesion on stiff matrix, and FBGC formation in primary mouse macrophages. In essence, our findings suggest that miR-146a might act as a suppressor of FBR. We expect that the results of this study may provide invaluable information and insight regarding the molecular mechanisms mediating the FBR to biomaterials, which may lead to the development of a novel microRNA-based therapeutic strategy for the amelioration of the poorly understood FBR to biomaterials. NIH (R01 AI172086) grant to Shaik O. Rahaman. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Spatially Resolved Molecular Analysis of Host Response to Medical Device Implantation Using the 3D OrbiSIMS Highlights a Critical Role for Lipids.

A key goal for implanted medical devices is that they do not elicit a detrimental immune response. Macrophages play critical roles in the modulation of the host immune response and are the cells responsible for persistent inflammatory reactions to implanted biomaterials. Two novel immune-instructive polymers that stimulate pro- or anti-inflammatory responses from macrophages in vitro are investigated. These also modulate in vivo foreign body responses (FBR) when implanted subcutaneously in mice. Immunofluorescent staining of tissue abutting the polymer reveals responses consistent with pro- or anti-inflammatory responses previously described for these polymers. Three Dimensional OrbiTrap Secondary Ion Mass Spectrometry (3D OrbiSIMS) analysis to spatially characterize the metabolites in the tissue surrounding the implant, providing molecular histology insight into the metabolite response in the host is applied. For the pro-inflammatory polymer, monoacylglycerols (MG) and diacylglycerols (DG) are observed at increased intensity, while for the anti-inflammatory coating, the number of phospholipid species detected decreased, and pyridine and pyrimidine levels are elevated. Small molecule signatures from single-cell studies of M2 macrophages in vitro correlate with the in vivo observations, suggesting potential for prediction. Metabolite characterization by the 3D OrbiSIMS is shown to provide insight into the mechanism of bio-instructive materials as medical devices and to inform on the FBR to biomaterials.

UNMET CLINICAL NEEDS AND CHALLENGES IN ORTHOPAEDIC IMPLANTS

Infections are among the most diffused complications of the implantation of medical devices. In orthopedics, they pose severe societal and economic burden and interfere with the capability of the implants to integrate in the host bone, significantly increasing failure risk. Infection is particularly severe in the case of comorbidities and especially bone tumors, since oncologic patients are fragile, have higher infection rate and impaired osteoregenerative capabilities. For this reason, prevention of infection is to be preferred over treatment.This is even more important in the case of spine surgery, since spine is among the main site for tumor metastases and because incidence of post operative surgical-site infections is significant (up to 15-20%) and surgical options are limited by the need of avoiding damaging the spinal cord.Functionalization of the implant surfaces, so as to address infection and, possibly, co- adjuvate anti-tumor treatments, appears as a breakthrough innovation. Unmet clinical needs in infection and tumors is presented, with a specific focus on the spine, then, new perspectives are highlighted for their treatment.

In vitro study of flow characteristics in abdominal aortic aneurysm

Hemodynamic factors play a key role in the endovascular aneurysm repair of abdominal aortic aneurysm (AAA). This study conducts an in vitro experiment in which a circulating platform for the experiment and modeling of the pulsatility of blood flow in the human body is established and combined with particle image velocimetry The characteristic parameter distribution of intra-tumoral flow under nonsteady conditions is investigated. Results show that counterflow is a crucial factor affecting the distribution of characteristics of nonsteady intra-tumoral flow, and the presence of single-peak pulsatile flow with counterflow causes the effects of counterflow to emerge at the tumor inlet from the near-wall region and then erode gradually to the streamwise flow region. The maximum intra-tumoral shear stress is found to be located at the near-wall region at the tumor inlet and outlet, and the counterflow formed from the attachment of vortices at the near-wall region leads to the drastic change of the intra-tumoral flow state. The results of the present experiment are useful for quantitatively evaluating the key areas of stress distribution in AAA, providing a basis for preventing risks during the implantation of medical devices.

The Use of 3D Printing and Nanotechnologies to Prevent and Inhibit Biofilms on Medical Devices

Biofilms remain one of the most pervasive complications of the medical field, representing 50–70% of all nosocomial infections and up to 80% of total microbial infections. Since biofilms contain intricately small matrices, different microenvironments, and accumulations of biodiverse microorganisms of different resistances, these structures end up being difficult to target. As we review in this paper, 3D printing and nanotechnology help overcome these unique challenges of targeting biofilms, especially within the medical field. These technologies bring versatility and more precise control to personalized reusable medical device development and implants, with enhanced antimicrobial characteristics. They allow for decreased surface roughness of the implants, smaller pores, more targeted topography, and even added antibiotic or drug-releasing abilities for the medical devices. Furthermore, combining 3D with nanoparticles allows for the creation of anodized nanosurfaces of medical implants with increased osseointegration and reduced polymerization while promoting cost efficiency, durability, and biocompatibility. In this review, we explore the potentially valuable antimicrobial consequences of applying 3D technology and nanoengineering to dental and orthodontic implants, oral prostheses, hearing aids, joint replacements, catheters, stents, endotracheal tubes, prosthetics, and bone scaffolds.

Changes in the levels of factor X (FXA) and factor XII (FXIIA) in patients after permanent pacemaker implantation

Introduction: There are considerable evidences for the activation of coagulation after implantation of medical devices. In addition, the categorical connection between PPM implantation and the development in time of CTEPH (chronic thromboembolic pulmonary hypertension) is proven. Objectives: To examine the levels of FXa and FXIIa during dynamic in patients after PPM implantation. Materials and methods: We examined the levels of FXa and FXIIa at the baseline, at 6 weeks, at 12 weeks and at 24 weeks after implantation of dual chamber PPM in 45 patients (25 men and 20 women – median age 72.18 ±9.08yrs.) and in 46 controls (22 women and 24 men – median age 71,96 ±8.75yrs.), corresponding in gender, age and BMI. The method of research was enzyme-linked immunosorbent assay. Results: The values of FXa and FXIIa at the baseline were not different in patients and controls 92.88 pg/ml vs 98,87 pg/ml (p>0.05) and 95.41 pg/ml vs 100.31 pg/ml (p>0.05). At the 6 and 12 weeks follow up checks, the values of FXa and FXIIa increased significantly compared to those in controls р<0.001 (tabl.1). At 24 weeks, the absolute values were still higher than those in controls, as for FXa the difference did not reach significant meaning (p>0.05) (tabl.1) and the values of FXIIa remained at significantly higher level compared to the controls (p<0.05) (tabl.1). Conclusion: Due to permanent maintenance of elevated levels of FXa and FXIIa, we believe it can be accepted that the implantation of PPM leads to a lasting procoagulant state.

Antibacterial Analysis on Everolimus Grafted Biomaterial Surfaces using Polydopamine Intermediate Layer for Potential Use on Medical Devices

Biomaterial-Centered Infection (BCI) is a significant issue in the implantation of medical devices, primarily caused by the formation of bacterial biofilms on the device surface. One potential solution to address this problem is the use of antibacterial coatings. This study examines the effectiveness of everolimus as an antibacterial coating agent with polydopamine (PDA) as an intermediate layer. The commonly used biomaterial for medical scaffolds, poly(lactic acid) (PLA), was coated with everolimus after being submerged in PDA for 24 hours. The coated PLA was then subjected to antibacterial analysis, including culturing Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria in Luria-Bertani broth, bacterial count tests, and disc inhibition tests. The results showed that everolimus has antibacterial properties, but its efficacy varies with different types of bacteria adhering to the biomaterial surfaces. Specifically, the everolimus coating was found to be more effective in killing Gram-positive S. aureus. The absence of inhibition zones and the lack of further growth of both Gram-positive S. aureus and Gram-negative E. coli on the samples demonstrated the controlled release of everolimus, indicating the potential of the PDA layer in holding the everolimus release to the surrounding. Therefore, the study concludes that the formation of everolimus coating on biomaterial surfaces aided by the PDA layer, have significant potential in retarding bacterial colonies on medical devices.

Silk fibroin-based coating with pH-dependent controlled release of Cu2+ for removal of implant bacterial infections

The implantation of medical devices is frequently accompanied by the invasion of bacteria, which may lead to implant failure. Therefore, an intelligent and responsive coating seems particularly essential in hindering implant-associated infections. Herein, a self-defensive antimicrobial coating, accompanied by silk fibroin as a valve, was successfully prepared on the titanium (Ti-Cu@SF) for pH-controlled release of Cu2+. The results showed that the layer could set free massive Cu2+ to strive against E. coli and S. aureus for self-defense when exposed to a slightly acidic condition. By contrary, a little Cu2+ was released in the physiological situation, which could avoid damage to the normal cells and showed excellent in vitro pH-dependent antibiosis. Besides, in vivo experiment confirmed that Ti-Cu@SF could work as an antibacterial material to kill S. aureus keenly and display negligible toxicity in vivo. Consequently, the design provided support for endowing the layer with outstanding biocompatibility and addressing the issue of bacterial infection during the implantation of Ti substrates.

Host–device interactions: exposure of lung epithelial cells and fibroblasts to nickel, titanium, or nitinol affect proliferation, reactive oxygen species production, and cellular signaling

Endoscopic implantation of medical devices for the treatment of lung diseases, including airway stents, unidirectional valves and coils, is readily used to treat central airway disease and emphysema. However, granulation and fibrotic tissue formation impairs treatment effectiveness. To date little is known about the interaction between implanted devices, often made from metals, such as nickel, titanium or nitinol, and cells in the airways. Here, we study the response of lung epithelial cells and fibroblasts to implant device materials. The adhesion and proliferation of bronchial epithelial cells and lung fibroblasts upon exposure to 10 × 3 × 1 mm pieces of nickel, titanium or nitinol is examined using light and scanning electron microscopy. Pro-inflammatory cytokine mRNA expression and release, signaling kinase activity and intracellular free radical production are assessed. Nitinol, and to a lesser extent nickel and titanium, surfaces support the attachment and growth of lung epithelial cells. Nitinol induces a rapid and significant alteration of kinase activity. Cells directly exposed to nickel or titanium produce free radicals, but those exposed to nitinol do not. The response of lung epithelial cells and fibroblasts depends on the metal type to which they are exposed. Nitinol induces cellular surface growth and the induction of kinase activity, while exposure of lung epithelial cells to nickel and titanium induces free radical production, but nitinol does not.Graphical

Cd13 controls myeloid cell-cell fusion

Abstract Macrophages have the ability to undergo phenotypic and functional changes in response to microenvironmental cues. One such change is the formation of multinucleated giant cells (MGCs) via intercellular fusion triggered by certain bacterial or parasitic infections or implantation of medical devices that induces deleterious MGC formation in response to the foreign body. Despite advances in biomaterials, implants ultimately corrode to produce particles that initiate a foreign body response characterized by macrophage fusion into pro-inflammatory, Foreign Body Giant Cells that directly define the pathology of loosening of medical implants. We have shown that the transmembrane protein CD13 is a multifunctional molecule that regulates diverse processes such as cell-cell adhesion, receptor endocytosis and recycling and organization of the actin cytoskeleton, all of which are critical in cell-cell fusion. We demonstrate that subcutaneous foreign implants in CD13 KOmice produce significantly more MGCs with increased levels of plasma pro-inflammatory cytokines. In vitro induction of fusion in CD13-deficient myeloid progenitors generated from bone marrow resulted in hyperfusion to generate MGCs that were considerably larger in size and contained many more nuclei than those from wild type progenitors, suggesting that CD13 regulates MGC formation at the stage of fusion. While expression of the key fusion proteins are typically downregulated in mature cells post-fusion, expression of these proteins is sustained at high levels in multinucleated cells lacking CD13. Thus, CD13 acts as a brake to prevent aberrant myeloid cell-cell fusion and may be a novel therapeutic target in pathological conditions mediated by abnormal cell fusion. Supported by grants from NIH (1R21 AI15 )

Advances in Injectable Hydrogel Strategies for Heart Failure Treatment.

Heart failure (HF) affects 60 million people worldwide and has developed into a global public health problem surpassing cancer and urgently needs to be solved. According to the etiological spectrum, HF due to myocardial infarction (MI) has become the dominant cause of morbidity and mortality. Possible treatments include pharmacology, medical device implantation, and cardiac transplantation, which are limited in their ability to promote long-term functional stabilization of the heart. Injectable hydrogel therapy has emerged as a minimally invasive tissue engineering treatment approach. Hydrogels can provide the necessary mechanical support for the infarcted myocardium and serve as carriers of various drugs, bioactive factors and cells to improve the cellular microenvironment in the infarcted region and induce myocardial tissue regeneration. Herein, we explored the pathophysiological mechanism of HF and summarized injectable hydrogels as a potential solution for current clinical trials and applications. Specifically, mechanical support hydrogels, decellularized ECM hydrogels, a variety of biotherapeutic agent-loaded hydrogels and conductive hydrogels for cardiac repair were discussed, and the mechanism of action of these hydrogel-based therapies was emphasized. Finally, the limitations and future prospects of injectable hydrogel therapy for HF post MI were proposed to inspire novel therapeutic strategies. This article is protected by copyright. All rights reserved.

Computed tomography Osteoabsorptiometry: Review of bone density, mechanical strength of material and clinical application.

Computed Tomography (CT) imaging is an effective non-invasive examination. It is widely used in the diagnosis of fractures, arthritis, tumor, and some anatomical characteristics of patients. The density value (Hounsfield unit, HU) of a material in computed tomography can be the same for materials with varying elemental compositions. This value depends on the mass density of the material and the degree of X-ray attenuation. Computed Tomography Osteoabsorptiometry (CTOAM) imaging technology is developed on the basis of CT imaging technology. By applying pseudo-color image processing to the articular surface, it is used to analyze the distribution of bone mineralization under the articular cartilage, evaluate the position of prosthesis implantation, track the progression of osteoarthritis, and determine the joint injury prognosis. Furthermore, this technique was combined with indentation testing to discuss the relationship between the high bone density area of the articular surface, the mechanical strength of the bone, and the anchorage stability of the implant, in addition to the study of the relationship between mechanical strength and bone density. This narrative study discusses the pre- and postoperative evaluation of medical device implantation position, orthopedic surgery, and the clinical treatment of bone injury and degeneration. It also discusses the research status of CTOAM technology in image post-processing engineering and the relationship between bone material and mechanical strength.

Engineering In Situ Weldable Vascular Devices.

(1) Background: The minimally invasive implantation of medical devices is largely limited by their insertion profile, and, therefore, minimizing them constitutes a leading trend in the field. (2) Methods: This study introduces the in situ welding strategy, whereby the components of the stent grafts used to treat abdominal aortic aneurysms were decoupled, deployed sequentially, and welded together at the aneurysmal site, greatly reducing their insertion profile. Polyurethane elastomers were used to produce the graft and to coat the metallic struts of the stent to render it in vivo weldable. Results: The composition of the polyurethanes was fine-tuned, so to minimize the insertion profiles and optimize the welding properties and the clinical performance of the devices assembled. The stent and graft were deployed successively in pigs via a small 8F introducer, in situ welded, and the patency of the bi-component device was confirmed over a three-month post-implantation period. The strength of the stent/graft welded connection was fully retained, with no de-welding observed. Conclusions: The in situ welding strategy resulted in implantations that were easier to perform and markedly less injurious to tissues and organs, largely expanding the applicability of these ultra-minimally invasive procedures to especially frail segments of the population.

Magnetic Systems for Regenerative Medicine

Magnetic Systems for Regenerative Medicine

Regeneration of infarcted hearts by myocardial infarction-responsive injectable hydrogels with combined anti-apoptosis, anti-inflammatory and pro-angiogenesis properties

Current treatments including drug therapy, medical device implantation, and organ transplantation have considerable shortcomings for myocardial infarction (MI), such as high invasiveness, the scarce number of donor organs, easy thrombosis, immune rejection, and poor therapeutic effects. Therefore, the development of new solutions to repair infarcted hearts is urgently needed. Smart responsive injectable hydrogels have served as a good foundation in biomedical engineering, especially for cardiac regeneration. Herein, we synthesized an injectable hydrogel that responds to the inflammatory microenvironment at the site of MI to provide the drug curcumin (Cur) and tailored recombinant humanized collagen type III (rhCol III) in a controlled manner for myocardial repair. The excellent antioxidant and anti-inflammatory properties of Cur could effectively reduce the ROS level and cell apoptosis and inhibit inflammatory reactions after MI. The tailored rhCol III promoted cell proliferation, migration, and angiogenesis. The therapeutic hydrogel resulted in the rapid recovery of cardiac function after MI by elevating the expression of the cardiac markers α-actinin and CX 43. In vitro and in vivo data showed that the combined anti-apoptosis, anti-inflammatory and pro-angiogenesis treatment strategies were an auspicious tactic for the treatment of MI, and had significant clinical application value. Furthermore, the work also demonstrated the great application potential of our tailored rhCol III in promoting the repair and regeneration of infarcted hearts.

Real World studies on undesirable effects of some Anti-Thrombotic Drugs in a tertiary Hospital

Introduction: Antithrombotic drugs include antiplatelet, anticoagulant and fibrinolytics. Antithrombotic drugs either block the formation of new clots, or prevent the growth of existing clots or reduce risk of complications from blood clots. These drugs are used in various Cardio and neurological diseases ranging from Angina, stroke to as Dual Antiplatelet Therapy (DAT) in post implantation of permanent medical devices. Antithrombotic drugs have numerous side effects from gastritis, prolonged bleeding, hemorrhage, tachycardia, tinnitus based on the class of drugs.
 Study design and Objective: Though the undesirable effects of antithrombotic drugs are well established in controlled trails, there were rare studies in Real world population. Hence a prospective observational study was under taken to understand the undesirable effects in a Tertiary hospital in India and analyze the pattern based on age, gender, intended and indications of use and dosage regimen. The undesirable effects of Aspirin, Heparin and Clopidogrel were studied in 92 patients over a period of 6 months.
 Results and Discussion: In the current study there were 8 cases were heparin was indicated and 50% of the patients complained of haemorrhage / bleeding and in 2 cases there is heavy bleeding during cut wounds. All this cases were found in patients where Heparin is used in Cardiology and neurological diseases and old age group on different indications of use. In 60 patients who are on Aspirin therapy 43 patients are in cardiology and 17 in neurological treatment. Most of the indications are for CAD, Myocardial Infraction (MI) and Angina. Important undesirable effects noted in the present study include SOB-9 patients, Tachycardia- 5, Blood in stools-4 patients, Tinnitus -3 patients and Ulcers in 3 patients. Of the 92 cases, Clopidogrel was prescribed for different indications of use in 24 patients. Of them 19 patients are in cardiology and 5 patients are in neurology treatment. Most commonly patients were diagnosed with MI, unstable angina and CVA Ischemic stroke, with observed undesirable effects like prolonged bleeding, dyspepsia, headache, indigestion, heart burn and tachycardia. The study clearly shows that prolonged bleeding was observed in 40% of the patients on clopidogrel mainly in segment with higher doses and on co-medication
 Conclusion: The present study has shown similar undesirable effects evidenced in controlled clinical trials. However, the study indicates Intravenous administration of Heparin is advised than subcutaneous route and need for larger studies to substantiate the same. It is also recommended that patients on Aspirin should be recommended for low dose mainly in indications related to cardiovascular diseases than higher dosed. Most of the adverse effects are found in patients taking more than 75 mg and BID and TID. It could be related to dose induced effects and also the includes the age factor as most of them are geriatrics and not on anti-ulcer drugs. The study clearly shows that prolonged bleeding was observed in 40% of the patients on clopidogrel mainly in segment with higher doses and on co-medication. A case was reported on overdose of Clopidogrel which resulted in abnormalities in platelet aggregation that required emergency medical care.

Bacteriophobic Zwitterionic/Dopamine Coatings for Medical Elastomers

AbstractDespite modern advancements in sterilization and medical practices, bacterial infections remain a significant concern in the implantation of medical devices. There is currently an urgent need for long‐lasting and high‐stable strategies to avoid the adhesion of bacteria to the wide range of materials present in medical devices. Here, a versatile methodology to create anti‐biofouling coatings that prevent the adhesion of bacteria to silicone‐based materials used in healthcare is reported. These coatings consist of bifunctional ethylene glycol dimethacrylate as an anchor between a zwitterionic polymer (SBMA), which provides antifouling properties, and a polydopamine layer that operates as an interfacial binder, providing mechanical strength and strong adhesion to elastomeric substrates. The coatings exhibit superhydrophilic and anti‐biofouling properties, creating a strong “bacteriophobic effect” that leads to a >99% reduction in bacterial adhesion. This bacteriophobic coating is successfully implemented and validated in a commercial urinary catheter, reducing bacterial adhesion by 1–2 orders of magnitude and avoiding bacterial colonization to prevent catheter‐associated urinary tract infections. The results presented here demonstrate the versatility, durability, and scalability of the coating methodology for preventing bacterial adhesion in silicone elastomers, which can be easily applied to other elastomeric materials used in medical devices beyond urinary tract infection prevention.

Bactericidal Anti-Adhesion Potential Integrated Polyoxazoline/Silver Nanoparticle Composite Multilayer Film with pH Responsiveness.

Bacterial infections occur frequently during the implantation of medical devices, and functional coating is one of the effective means to prevent and remove biofilms. In this study, three different hydrophilic polyoxazolines with carboxyl groups (aPOx: PT1, PT2 and PT3) and bactericidal silver nanoparticles (AgNPs) were synthesized successfully, and an aPOx-AgNP multilayer film was prepared by electrostatic layer-by-layer self-assembly. The effect of charge density and assembly solution concentration was explored, and the optimal self-assembly parameters were established (PT2 1 mg/mL and AgNPs 3 mg/mL). The hydrophilicity of the surface can be enhanced to resist protein adhesion if the outermost layer is aPOx, and AgNPs can be loaded to kill bacteria, thereby realizing the bactericidal anti-adhesion potential integration of the aPOx-AgNP multilayer film. In addition, the aPOx-AgNP multilayer film was found to have the characteristic of intelligent and efficient pH-responsive silver release, which is expected to be used as a targeted anti-biofilm surface of implantable medical devices.

Bioinspired zwitterionic microgel-based coating: Controllable microstructure, high stability, and anticoagulant properties

Zwitterionic polymers have shown promising results in non-fouling and preventing thrombosis. However, the lack of controlled surface coverage hinders their application for biomedical devices. Inspired by the natural biological surfaces, a facile zwitterionic microgel-based coating strategy is developed by the co-deposition of poly (sulfobetaine methacrylate-co-2-aminoethyl methacrylate) microgel (SAM), polydopamine (PDA), and sulfobetaine-modified polyethyleneimine (PES). The SAMs were used to construct controllable morphology by using the PDA combined with PES (PDAS) as the intermediate layer, which can be easily modulated via adjusting the crosslinking degree and contents of SAMs. The obtained SAM/PDAS coatings exhibit high anti-protein adhesive properties and can effectively inhibit the adhesion of cells, bacteria, and platelet through the synergy of high deposition density and controllable morphology. In addition, the stability of SAM/PDAS coating is improved owing to the anchoring effects of PDAS to substrate and SAMs. Importantly, the ex vivo blood circulation test in rabbits suggests that the SAM/PDAS coating can effectively decrease thrombosis without anticoagulants. This study provides a versatile coating method to address the integration of zwitterionic microgel-based coatings with high deposition density and controllable morphology onto various substrates for wide biomedical device applications. Statement of significanceThrombosis is a major cause of medical device implantation failure, which results in significant morbidity and mortality. In this study, inspired by natural biological surfaces (fish skin and vascular endothelial layer) and the anchoring ability of mussels, we report a convenient and efficient method to firmly anchor zwitterionic microgels using an oxidative co-deposition strategy. The prepared coating has excellent antifouling and antithrombotic properties through the synergistic effect of physical morphology and chemical composition. This biomimetic surface engineering strategy is expected to provide new insights into the clinical problems of blood-contacting devices related to thrombosis.