Inflammasomes as regulators of mechano-immunity.

Mechano-immunity, the intersection between cellular or tissue mechanics and immune cell function, is emerging as an important factor in many inflammatory diseases. Mechano-sensing defines how cells detect mechanical changes in their environment. Mechano-response defines how cells adapt to such changes, e.g. form synapses, signal or migrate. Inflammasomes are intracellular immune sensors that detect changes in tissue and cell homoeostasis during infection or injury. We and others recently found that mechano-sensing of tissue topology (swollen tissue), topography (presence and distribution of foreign solid implant) or biomechanics (stiffness), alters inflammasome activity. Once activated, inflammasomes induce the secretion of inflammatory cytokines, but also change cellular mechanical properties, which influence how cells move, change their shape, and interact with other cells. When overactive, inflammasomes lead to chronic inflammation. This clearly places inflammasomes as important players in mechano-immunity. Here, we discuss a model whereby inflammasomes integrate pathogen- and tissue-injury signals, with changes in tissue mechanics, to shape the downstream inflammatory responses and allow cell and tissue mechano-adaptation. We will review the emerging evidence that supports this model.

Macrophages modulate stiffness-related foreign body responses through plasma membrane deformation.

Implants are widely used in medical applications and yet macrophage-mediated foreign body reactions caused by implants severely impact their therapeutic effects. Although the extensive use of multiple surface modifications has been introduced to provide some mitigation of fibrosis, little is known about how macrophages recognize the stiffness of the implant and thus influence cell behaviors. Here, we demonstrated that macrophage stiffness sensing leads to differential inflammatory activation, resulting in different degrees of fibrosis. The potential mechanism for macrophage stiffness sensing in the early adhesion stages tends to involve cell membrane deformations on substrates with different stiffnesses. Combining theory and experiments, we show that macrophages exert traction stress on the substrate through adhesion and altered membrane curvature, leading to the uneven distribution of the curvature-sensing protein Baiap2, resulting in cytoskeleton remodeling and inflammation inhibition. This study introduces a physical model feedback mechanism for early cellular stiffness sensing based on cell membrane deformation, offering perspectives for future material design and targeted therapies.

Prevention of the foreign body response to implantable medical devices by inflammasome inhibition.

SignificanceImplantable electronic medical devices (IEMDs) are used for some clinical applications, representing an exciting prospect for the transformative treatment of intractable conditions such Parkinson's disease, deafness, and paralysis. The use of IEMDs is limited at the moment because, over time, a foreign body reaction (FBR) develops at the device-neural interface such that ultimately the IEMD fails and needs to be removed. Here, we show that macrophage nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activity drives the FBR in a nerve injury model yet integration of an NLRP3 inhibitor into the device prevents FBR while allowing full healing of damaged neural tissue to occur.

Decoding the "Fingerprint" of Implant Materials: Insights into the Foreign Body Reaction.

Foreign body reaction (FBR) is a prevalent yet often overlooked pathological phenomenon, particularly within the field of biomedical implantation. The presence of FBR poses a heavy burden on both the medical and socioeconomic systems. This review seeks to elucidate the protein "fingerprint" of implant materials, which is generated by the physiochemical properties of the implant materials themselves. In this review, the activity of macrophages, the formation of foreign body giant cells (FBGCs), and the development of fibrosis capsules in the context of FBR are introduced. Additionally, the relationship between various implant materials and FBR is elucidated in detail, as is an overview of the existing approaches and technologies employed to alleviate FBR. Finally, the significance of implant components (metallic materials and non-metallic materials), surface CHEMISTRY (charge and wettability), and physical characteristics (topography, roughness, and stiffness) in establishing the protein "fingerprint" of implant materials is also well documented. In conclusion, this review aims to emphasize the importance of FBR on implant materials and provides the current perspectives and approaches in developing implant materials with anti-FBR properties.

[Silver Ion Decreases Foreign Body Reaction and Venous Neointimal Hyperplasia through the Inhibition of Interleukin-33 Expression].

INTRODUCTION: Vascular prosthetic grafts are widely used in vascular surgery; however, graft infection remains a major concern. Silver-coated vascular grafts have demonstrated anti-infection properties in clinical settings; however, whether the silver irons influence foreign body reaction or neointimal hyperplasia remains unclear. METHODS: Sodium alginate and hyaluronic acid (SA/HA) hydrogel patches loaded with rhodamine, with or without silver, were fabricated. Patches were implanted in the subcutaneous or abdominal cavity and inferior vena cava of rats. Samples were harvested on day 14 and examined via immunohistochemical and immunofluorescence analyses. RESULTS: Silver hydrogel was found to decrease the foreign body reaction; after subcutaneous and abdominal cavity implantation in rats, the capsule was found to be thinner in the silver hydrogel group than in the control hydrogel group. The silver hydrogel group had fewer CD68-positive cells and proliferating cell nuclear antigen and interleukin-33 (IL-33) dual-positive cells than the control hydrogel group. Additionally, the silver hydrogel patch reduced the neointimal thickness after patch venoplasty in rats, and the number of IL-33- and IL-1ß-positive cells was lower than that in the control patch. CONCLUSION: Silver-loaded SA/HA hydrogel patches decreased the foreign body reaction and venous neointimal hyperplasia in rats by the inhibition of IL-33 expression.

A Histological Assessment Tool for Breast Implant Capsules Validated in 480 Patients with and Without Capsular Contracture.

BACKGROUND: Understanding the impact of breast implants on the histological response in the surrounding fibrous capsule is important; however, consensus is lacking on how to analyze implant capsules histologically. We aimed to develop a standardized histological assessment tool to be used in research potentially improving diagnostic accuracy and treatment strategies for capsular contracture. METHODS: Biopsies of breast implant capsules from 480 patients who had undergone breast augmentation or reconstruction were collected and stained with hematoxylin and eosin. Initially, biopsies from 100 patients were analyzed to select histological parameters demonstrating the highest relevance and reproducibility. Then, biopsies from the remaining 380 patients were used to determine intra- and interobserver agreements of two blinded observers and agreement with a pathologist. Finally, we tested the association between the parameters and capsular contracture. RESULTS: The histological assessment tool included ten parameters assessing the inflammatory, fibrotic, and foreign-body reaction to breast implants, each graded on two-, three-, or four-point scales. Intra- and interobserver agreements were almost perfect (0.83 and 0.80), and agreement with the pathologist was substantial (0.67). Four parameters were significantly correlated with capsular contracture, namely chronic inflammation with lymphocyte infiltration (p < 0.01), thickness of the collagen layer (p < 0.0001), fiber organization (p < 0.01), and calcification (p < 0.001). CONCLUSIONS: This is the first validated histological assessment tool for breast implant capsules. The validated tool not only advances our understanding of capsular contracture but also sets a new standard for histological evaluation in breast implant research and clinical diagnostics. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

5-Fluorouracil Injection for the Treatment of a Suture-Induced Foreign Body Reaction after Blepharoplasty.

The continuously increasing number of blepharoplasty procedures has resulted in widespread concerns regarding postoperative complications. Embedded threads in blepharoplasty can cause foreign body reactions that can affect surgical outcomes. Foreign body reactions caused by sutures after blepharoplasty can be treated with local injection of 5-fluorouracil in the eyelid.Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Resveratrol Alleviates the Early Challenges of Implant-Based Drug Delivery in a Human Glial Cell Model.

Brain diseases are oftentimes life-threatening and difficult to treat. The local administration of drug substances using brain implants can increase on-site concentrations and decrease systemic side effects. However, the biocompatibility of potential brain implant materials needs to be evaluated carefully as implants can trigger foreign body reactions, particularly by increasing the microglia and astrocyte reactivity. To date, these tests have been frequently conducted in very simple in vitro models, in particular not respecting the key players in glial cell reactions and the challenges of surgical implantation characterized by the disruption of oxygen and nutrient supply. Thus, we established an in vitro model in which we treated human glial cell lines with reduced oxygen and glucose levels. The model displayed cytokine and reactive oxygen species release from reactive microglia and an increase in a marker of reactive astrocytes, galectin-3. Moreover, the treatment caused changes in the cell survival and triggered the production of hypoxia-inducible factor 1α. In this comprehensive platform, we demonstrated the protective effect of the natural polyphenol resveratrol as a model substance, which might be included in brain implants to ease the undesired glial cell response. Overall, a glial-cell-based in vitro model of the initial challenges of local brain disease treatment may prove useful for investigating new therapy options.

Amitriptyline efficacy in decreasing implant-induced foreign body reaction.

Beyond its actions on the nervous system, amitriptyline (AM) has been shown to lower inflammatory, angiogenic, and fibrogenic markers in a few pathological conditions in human and in experimental animal models. However, its effects on foreign body reaction (FBR), a complex adverse healing process, after biomedical material implantation are not known. We have evaluated the effects of AM on the angiogenic and fibrogenic components on a model of implant-induced FBR. Sponge disks were implanted subcutaneously in C57BL/6 mice, that were treated daily with oral administration of AM (5 mg/kg) for seven consecutive days in two protocols: treatment was started on the day of surgery and the implants were removed on the seventh day after implantation and treatment started 7 days after implantation and the implants removed 14 after implantation. None of the angiogenic (vessels, Vascular endothelial growth factor (VEGF), and interleukin-1ß (IL-1ß) or fibrogenic parameters (collagen, TGF-ß, and fibrous capsule) and giant cell numbers analyzed were attenuated by AM in 7-day-old implants. However, AM was able to downregulate angiogenesis and FBR in 14-day-old implants. The effects of AM described here expands its range of actions as a potential agent capable of attenuating fibroproliferative processes that may impair functionality of implantable devices.

Silk-Based Matrices and c-Kit-Positive Cardiac Progenitor Cells for a Cellularized Silk Fibroin Scaffold: Study of an in vivo Model.

The production of a cellularized silk fibroin scaffold is very difficult because it is actually impossible to differentiate cells into a well-organized cardiac tissue. Without vascularization, not only do cell masses fail to grow, but they may also exhibit an area of necrosis, indicating a lack of oxygen and nutrients. In the present study, we used the so-called tyrosine protein kinase kit (c-Kit)-positive cardiac progenitor cells (CPCs) to generate cardiac cellularized silk fibroin scaffolds, multipotent cells isolated from the adult heart to date that can show some degree of differentiation toward the cardiac phenotype. To test their ability to differentiate into the cardiac phenotype in vivo as well, CPC and collagen organoid-like masses were implanted into nude mice and their behavior observed. Since the 3-dimensional structure of cardiac tissue can be preserved by scaffolds, we prepared in parallel different silk fibroin scaffolds with 3 different geometries and tested their behavior in 3 different models of immunosuppressed animals. Unfortunately, CPC cellularized silk fibroin scaffolds cannot be used in vivo. CPCs implanted alone or in collagen type I gel were destroyed by CD3+ lymphocyte aggregates, whereas the porous and partially oriented scaffolds elicited a consistent foreign body response characterized by giant cells. Only the electrospun meshes were resistant to the foreign body reaction. In conclusion, c-Kit-positive CPCs, although expressing a good level of cardiac differentiation markers in vitro with or without fibroin meshes, are not suitable for an in vivo model of cardiac organoids because they are degraded by a T-cell-mediated immune response. Even scaffolds which may preserve the survival of these cells in vivo also induced a host response. However, among the tested scaffolds, the electrospun meshes (F-scaffold) induced a lower response compared to all the other tested structures.

Foreign body reaction after CyPass® Micro-Stent implantation: a case series.

PURPOSE: To retrospectively assess the histopathological particularities of explanted CyPass® Micro-Stent of patients with significant loss of endothelial cell density. METHODS: This is a case series of fourteen eyes from eleven patients who underwent CyPass® Micro-Stent implantation due to mild to moderate glaucoma and who subsequently suffered from loss of endothelial cell density. Therefore, the explantation of the device was necessary. In addition to the retrospective evaluation of the intraocular pressure and the endothelial cell density at the time of implantation and explantation, every surgically removed implant was histologically examined and evaluated. RESULTS: Fourteen eyes of eleven patients were in total analysed. The patients-seven males and four females-had a mean age of 62.9 years. The average time between CyPass implantation and explantation was 3.7 years. Eight patients suffered from primary-open-angle glaucoma (POAG), while two patients had a pseudoexfoliation glaucoma (PXG) and one patient had low-pressure glaucoma. Ten of the patients were already pseudophakic before the CyPass implantation and four patients underwent previously glaucoma interventions. There was a significant reduction in the intraocular pressure from 18.57 ± 5.27 mmHg at the time of implantation to 14.78 ± 3.32 mmHg at the time of explantation (p = 0.037). The average endothelial cell density decreased from 1843.67 ± 421.81 to 932.92 ± 412.86/mm2 at the time of explantation (p < 0.01). The histological findings showed a fibrous obliteration of the CyPass accompanied by a chronic granulomatous inflammation with giant cell macrophages. Histologically, these findings were consistent with a foreign body granuloma. CONCLUSIONS: Implants made of polyimides such as the CyPass® Micro-Stent are considered to be biocompatible, but there is no guarantee not to be obliterated or encapsulated. This is the first case series that has detected a foreign body granuloma in multiple eyes after CyPass implantation. However, there is no connection with the type of glaucoma, the extent of previous operations or with the presence of a prolonged postoperative inflammatory reaction.

Foreign body reactions related to orofacial esthetic fillers: A systematic review.

The aim of this study was to systematically review the clinicopathological data regarding foreign body reactions (FBR) related to esthetic procedures in the orofacial region. Electronic searches were performed in six databases and in gray literature using PEO acronym for the review question. Case series and case reports describing FBR related to esthetic procedures in the orofacial region were included. The JBI Critical Appraisal Checklist-University of Adelaide tool was used for measuring the risk of bias. Eighty-six studies reporting 139 cases of FBR were identified. The mean age at diagnosis was 54.12 years (14-85 years), with most of the cases reported in America, North America (n = 42/30.70%) and Latin America (n = 33/23.60%), mainly occurring in women (n = 131/94.40%). Asymptomatic (n = 60/43.40%) nodules (n = 71/50.60%) were the main clinical characteristics. The lower lip represented the most affected anatomical location (n = 28/22.20%), followed by the upper lip (n = 27/21.60%). Surgical removal was the treatment of choice (n = 53/35.70%). Twelve different dermal fillers were reported in the study, and the microscopic characteristics of the cases varied according to the material used. The results based on case series and case reports showed that nodule and swelling were the main clinical characteristics of FBR related to orofacial esthetic fillers. The histological characteristics depended on the type of the filler material used.

Otologic use of porcine small intestinal submucosal graft (biodesign): A MAUDE database review.

OBJECTIVE: To review and summarize reported adverse events related to the use of porcine small intestine submucosal grafts (Biodesign™) in otologic procedures. STUDY DESIGN: Retrospective cross-sectional analysis. SETTING: Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database. MATERIAL AND METHODS: The MAUDE database was queried for all medical device reports (MDR) related to otologic use of Biodesign™ (Cook Medical, Bloomington, IN) from January 2016 to November 2022. Adverse events (AEs) were identified by reviewing all reports with the basic search term "Biodesign" and "Biodesign, Otologic". Reports were individually reviewed and categorized with special attention to AEs. RESULTS: A total of 500 reports were reviewed. Since FDA approval of Biodesign™ in 2016, there have been 5 adverse events reported for use of Biodesign™ during otologic surgery (tympanoplasty, n = 3; stapes surgery, n = 2). All reported events described patient injury, and all cases required at least one revision surgery. Four cases described significant foreign body inflammatory reactions. Complications included hearing loss (n = 3), severe otalgia (n = 2), persistent perforation (n = 2), vertigo (n = 2), and facial paralysis (n = 1). CONCLUSION: The use of porcine small intestinal submucosal graft has been thought to be a safe and effective option for otologic surgery, with the advantage of availability without graft harvest in minimally invasive endoscopic surgery. However, foreign body or granulomatous reactions have been documented and should be considered prior to its use in otologic surgery.

Intracranial sewing needle - accidentally inserted from a traditional cap worn by infants.

Patients with intracranial needles have rarely been reported. Several foreign bodies penetrating the cranium such as knives, nails, pencils, and wood pieces have been described in the literature. It is rare to discover a foreign body which has been inserted through either of the fontanelles before their closure in an attempted infanticide. Here we report one such rare case of intracranial sewing needle in a 24-year-old female which was accidentally inserted through the open anterior fontanelle from the traditional skull cap she was wearing during infancy. The needle was discovered incidentally on a routine skull radiograph done for a minor head injury. It was decided against any intervention to remove the needle owing to the fact that the presence of the foreign object was not causing any symptoms.

Influence of bone wax on bone healing: a case report and literature review.

The purposes of this article are to report the clinical case of a patient who exhibited a foreign body reaction associated with the use of bone wax after extraction of an impacted third molar and to present an integrative literature review addressing the possible influences of this hemostatic agent on bone healing. A 26-year-old woman who underwent the extraction of her mandibular right third molar developed intense alveolar bleeding during surgery, requiring the use of bone wax. In the 2-month postoperative period, the patient presented with intraoral edema and discharge of a purulent secretion via the alveolar route. After cone beam computed tomographic images revealed increased hyperdensity inside the alveolus, alveolar curettage was performed and the material that was obtained was submitted to histopathologic examination. The results of the histopathologic analysis proved conclusive for an inflammatory foreign body reaction associated with exogenous material. A search of the PubMed, SciELO, and LILACS databases identified 22 studies that evaluated the influence of this hemostatic agent on bone healing, and an integrative review involving 367 animals and 75 humans was compiled. Bone wax is a nonresorbable material capable of negatively influencing bone healing. It is suggested that the product be used cautiously in amounts that are just enough to promote the sealing of the bone channels.

A New Modified Bipedicle Scrotal Skin Flap Technique for the Reconstruction of Penile Skin in Patients with Paraffin-Induced Sclerosing Lipogranuloma of the Penis.

PURPOSE: We introduce a new modified penile skin reconstruction technique to treat paraffin-induced sclerosing lipogranuloma of the penis. MATERIALS AND METHODS: From 2017 to 2020, 49 patients underwent the procedure. Complete removal of the lipogranuloma-involved penile skin was performed. A subcutaneous tunnel was then created between a horizontal scrotal incision and a proximal penile circumferential incision. The denuded penis was pulled through the tunnel, and a subcoronal and longitudinal dorsal penile suture line was made. An inverted V-shaped incision was made on the scrotum on the ventral side of the penis, followed by longitudinal closure. Outcomes and complications of the procedure were retrospectively studied. The long-term effect of surgery on sexual function and overall satisfaction was measured using a patient-reported questionnaire, which was completed by 30 patients. RESULTS: The overall complication rate was 26.5%. Clavien-Dindo grade 1, 2, 3a, 3b, 4 and 5 complications occurred in the postoperative period 5, 0, 8, 1, 0 and 0 times, respectively, in 13 patients. Surgery was successful in 27 (90%) patients according to the patient-reported questionnaire. Erectile dysfunction, pain/tension during erection, premature ejaculation and penile lymphedema were observed in 2, 3, 1 and 1 patients, respectively. All patients reported sexual intercourse ability. CONCLUSIONS: The type of penile skin reconstruction after the removal of sclerosing lipogranuloma of the penis is controversial. The reconstruction technique presented herein is an effective single-stage treatment option with a high success rate in patients with sclerosing lipogranuloma of the penis with intact scrotal skin.

Interactions between the foreign body reaction and Staphylococcus aureus biomaterial-associated infection. Winning strategies in the derby on biomaterial implant surfaces.

Biomaterial-associated infections (BAIs) are an increasing problem where antibiotic therapies are often ineffective. The design of novel strategies to prevent or combat infection requires a better understanding of how an implanted foreign body prevents the immune system from eradicating surface-colonizing pathogens. The objective of this review is to chart factors resulting in sub-optimal clearance of Staphylococcus aureus bacteria involved in BAIs. To this end, we first describe three categories of bacterial mechanisms to counter the host immune system around foreign bodies: direct interaction with host cells, modulation of intercellular communication, and evasion of the immune system. These mechanisms take place in a time frame that differentiates sterile foreign body reactions, BAIs, and soft tissue infections. In addition, we identify experimental interventions in S. aureus BAI that may impact infectious mechanisms. Most experimental treatments modulate the host response to infection or alter the course of BAI through implant surface modulation. In conclusion, the first week after implantation and infection is crucial for the establishment of an S. aureus biofilm that resists the local immune reaction and antibiotic treatment. Although established and chronic S. aureus BAI is still treatable and manageable, the focus of interventions should lie on this first period.

Systems of conductive skin for power transfer in clinical applications.

The primary aim of this article is to review the clinical challenges related to the supply of power in implanted left ventricular assist devices (LVADs) by means of transcutaneous drivelines. In effect of that, we present the preventive measures and post-operative protocols that are regularly employed to address the leading problem of driveline infections. Due to the lack of reliable wireless solutions for power transfer in LVADs, the development of new driveline configurations remains at the forefront of different strategies that aim to power LVADs in a less destructive manner. To this end, skin damage and breach formation around transcutaneous LVAD drivelines represent key challenges before improving the current standard of care. For this reason, we assess recent strategies on the surface functionalization of LVAD drivelines, which aim to limit the incidence of driveline infection by directing the responses of the skin tissue. Moreover, we propose a class of power transfer systems that could leverage the ability of skin tissue to effectively heal short diameter wounds. In this direction, we employed a novel method to generate thin conductive wires of controllable surface topography with the potential to minimize skin disruption and eliminate the problem of driveline infections. Our initial results suggest the viability of the small diameter wires for the investigation of new power transfer systems for LVADs. Overall, this review uniquely compiles a diverse number of topics with the aim to instigate new research ventures on the design of power transfer systems for IMDs, and specifically LVADs.

The role of foreign body response in peri-implantitis: What is the evidence?

Historically, there has been broad consensus that osseointegration represents a homeostasis between a titanium dental implant and the surrounding bone, and that the crestal bone loss characteristic of peri-implantitis is a plaque-induced inflammatory process. However, this notion has been challenged over the past decade by proponents of a theory that considers osseointegration an inflammatory process characterized by a foreign body reaction and peri-implant bone loss as an exacerbation of this inflammatory response. A key difference in these two schools of thought is the perception of the relative importance of dental plaque in the pathogenesis of crestal bone loss around implants, with obvious implications for treatment. This review investigates the evidence for a persistent foreign body reaction at osseointegrated dental implants and its possible role in crestal bone loss characteristic of peri-implantitis. Further, the role of implant-related material release within the surrounding tissue, particularly titanium particles and corrosion by-products, in the establishment and progression in peri-implantitis is explored. While it is acknowledged that these issues require further investigation, the available evidence suggests that osseointegration is a state of homeostasis between the titanium implant and surrounding tissues, with little evidence that a persistent foreign body reaction is responsible for peri-implant bone loss after osseointegration is established. Further, there is a lack of evidence for a unidirectional causative role of corrosion by-products and titanium particles as possible non-plaque related factors in the etiology of peri-implantitis.

A Soft Zwitterionic Hydrogel as Potential Coating on a Polyimide Surface to Reduce Foreign Body Reaction to Intraneural Electrodes.

Invasive intraneural electrodes can control advanced neural-interfaced prostheses in human amputees. Nevertheless, in chronic implants, the progressive formation of a fibrotic capsule can gradually isolate the electrode surface from the surrounding tissue leading to loss of functionality. This is due to a nonspecific inflammatory response called foreign-body reaction (FBR). The commonly used poly(ethylene glycol) (PEG)-based low-fouling coatings of implantable devices can be easily encapsulated and are susceptible to oxidative damage in long-term in vivo applications. Recently, sulfobetaine-based zwitterionic hydrogels have emerged as an important class of robust ultra-low fouling biomaterials, holding great potential to mitigate FBR. The aim of this proof-of-principle in vitro work was to assess whether the organic zwitterionic-poly(sulfobetaine methacrylate) [poly(SBMA)]-hydrogel could be a suitable coating for Polyimide (PI)-based intraneural electrodes to reduce FBR. We first synthesized and analyzed the hydrogel through a mechanical characterization (i.e., Young's modulus). Then, we demonstrated reduced adhesion and activation of fibrogenic and pro-inflammatory cells (i.e., human myofibroblasts and macrophages) on the hydrogel compared with PEG-coated and polystyrene surfaces using cell viability assays, confocal fluorescence microscopy and high-content analysis of oxidative stress production. Interestingly, we successfully coated PI surfaces with a thin film of the hydrogel through covalent bond and demonstrated its high hydrophilicity via water contact angle measurement. Importantly, we showed the long-term release of an anti-fibrotic drug (i.e., Everolimus) from the hydrogel. Because of the low stiffness, biocompatibility, high hydration and ultra-low fouling characteristics, our zwitterionic hydrogel could be envisioned as long-term diffusion-based delivery system for slow and controlled anti-inflammatory and anti-fibrotic drug release in vivo.