Antibiotic Coatings Research Articles

(129) Prophylactic Dips and Irrigation Solutions Can Considerably Alter the Antimicrobial Efficacy of Inflatable Penile Implant Hydrophilic Surface Coatings

Abstract Introduction Inflatable penile prostheses (IPP) experience surface-associated bacterial biofilms, which may contribute to clinical infections. Current attempts to reduce bacterial colonization include antibiotic coatings, altered implant surface binding properties, and mechanical irrigations. 0.05% chlorhexidine gluconate (CHG) has been proposed as a hydrophilic surface coating and mechanical irrigation for IPP surgery. One study demonstrated reduced surface bacterial colonization on an IPP hydrophilic surface dipped and irrigated with CHG 15psi compared to normal saline. However, CHG’s efficacy has not been compared to that of an antibiotic, particularly in preventing colonization by bacteria that are commonly implicated in IPP infections. Objective To characterize the utility of 0.05% chlorhexidine or vancomycin/gentamicin (VG) as both an antibiotic dip and an intraoperative irrigation in reducing bacterial colonization on hydrophilic IPP surfaces. Methods Sterile 8mm diameter IPP pieces (Coloplast, Minneapolis, MN) underwent the following treatment protocols. 1: IPP pieces were split into three groups (10 replicates each) and submerged for 3 minutes in normal saline (NS), 0.05% CHG in sterile water (Irrimax, Lawrenceville, GA), or a solution of 2mg/mL vancomycin and 160μg/mL gentamicin (VG) (Sigma-Aldrich, Burlington, MA) 2: IPP pieces were split into six groups (>14 replicates each) and submerged for 3 minutes in either NS, 0.05% CHG, or VG. Pieces were then rinsed in NS for five seconds and re-submerged in a separate well containing NS, 0.05% CHG, or VG. The pieces were rinsed in NS to remove any unbound solution and then incubated with 1*10^5 CFU/mL of methicillin-sensitive Staphylococcus aureus ATCC25923 in trypticase soy broth (TSB) for 48 hours. Samples were then rinsed with PBS and adherent bacteria were removed by shaking in 0.3% Tween-20. Suspended bacteria were serially diluted, plated onto 3M PetriFilms (Maplewood, MN), and counted. Mann-Whitney U tests were performed to compare outcomes, p<0.05 considered significant. Results Average bacterial counts with 95% CI’s for protocols 1 and 2 are plotted in Figures 1a and 1b respectively. NS controls showed an average of 1.1E7 CFU/mL adherent bacteria. Pre-dipping the implant in 0.05% CHG inhibits bacterial growth with a nearly ~2 log decrease (4.9E5 CFU/mL, p<0.01) in counts. Pre-dipping with VG had greater potency, with a ~5 log decrease (3.7E1 CFU/mL. p<0.01). However, exposure of the previously dipped IPP surface to an antiseptic irrigation solution altered antimicrobial properties (Figure 1b). NS controls showed an average of 6.0E7 CFU/mL adherent bacteria. The introduction of NS or CHG to the VG-coated implant material resulted in a near-complete loss of antimicrobial efficacy, with a 0.5 log decrease (NS) and a slight increase (CHG) in bacterial growth (NS: 5.5E7 CFU/mL, p=0.433; CHG: 6.2E7, p=.983). VG dipping followed by VG irrigation resulted in retention of antimicrobial properties, with a similar 5 log decrease. Conclusions Dipping of the implant surface with VG was more effective than 0.05% CHG. Furthermore, the choice of irrigation solution appears to alter the efficacy of antimicrobials bound to the hydrophilic IPP surface. Surgeons should be cautious using CHG or NS as an irrigation solution, and, if utilized, should take care to limit the contact time with the antibiotic-coated implant. Disclosure Yes, this is sponsored by industry/sponsor: Coloplast (material not financial support). Clarification: Industry funding only - investigator initiated and executed study. Any of the authors act as a consultant, employee or shareholder of an industry for: Coloplast and Boston Scientific.

Hydrogel Coating versus Calcium Sulphate Beads as a Local Antibiotic Carrier for Debridement Procedures in Acute Periprosthetic Joint Infection: A Preliminary Study.

Periprosthetic joint infections (PJI) are among the most difficult complications to treat in orthopaedic surgery. Debridement, antibiotics, and implant retention (DAIR) represent an efficient strategy for acute PJI, especially when resorbable local antibiotic carriers and coatings are used. The aim of this pilot study was to evaluate the difference between using antibiotic-loaded hydrogel (ALH) and calcium sulphate (CS) beads in the DAIR procedure. We analysed 16 patients who had been treated since 2018 for acute PJI, namely eight patients with knee PJI (50%), seven with hip PJI (43.7%), and one with shoulder PJI (6.2%). Nine patients were treated with the Debridement, Antibiotic Coating and Retention of the Implant (DACRI) method, while seven were treated with the Debridement, Antibiotic Pearls, Retention of the Implant (DAPRI) method. We found no significant differences between the two groups in terms of age, sex, the American Society of Anesthesiologists risk score, Charlson Comorbidity Index, localisation, days from onset to diagnosis and pathogenesis. Furthermore, no differences were found between the DACRI and DAPRI groups in terms of infection control (15 patients, 93.75% with p = 0.36) and last C-Reactive Protein values (p = 0.26), with a mean follow-up of 26.1 ± 7.7 months. Treatment for one patient affected by knee Candida albicans PJI in the DACRI group was not successful. In conclusion, DAPRI and DACRI appear to be safe and effective treatments for PJIs. This evidence will encourage the development of new clinical research into local carriers and coatings for use in acute implant-associated infections.

INFLUENCE OF ANTIBACTERIAL IMPLANT COATINGS ON THE VIABILITY OF GRAM-POSITIVE AND GRAM-NEGATIVE BACTERIA AND THE IN VITRO MINERALIZATION

The implantation of endoprosthesis is a routine procedure in orthopaedics. Endoprosthesis are mainly manufactured from ceramics, polymers, metals or metal alloys. To ensure longevity of the implants they should be as biocompatible as possible and ideally have antibacterial properties, to avoid periprosthetic joint infections (PJI). Various antibacterial implant materials have been proposed, but have so far only been used sporadically in patients. PJI is one of the main risk factors for revision surgeries. The aim of the study was to identify novel implant coatings that both exhibit antibacterial properties whilst having optimal biocompatibility.Six different novel implant coatings and surface modifications (EBM TiAl6V4, strontium, TiCuN, TiNbN, gentamicin phosphate (GP), gentamicin phosphate+cationic polymer (GP+CP)) were compared to standard CoCrMo-alloy. The coatings were further characterized with regard to the surface roughness. E. coli and S. capitis were cultured on the modified surfaces to investigate the antibacterial properties. To quantify bacterial proliferation the optical density (OD) was measured and viability was determined using colony forming units (CFU). Murine bone marrow derived macrophages (BMMs) were cultured on the surfaces and differentiated into osteoblasts to quantify the mineralisation using the alizarin red assay.All novel coatings showed reduced bacterial proliferation and viability compared to standard CoCrMo-alloy. A significant reduction was observed for GP and GP+CP coated samples compared to CoCrMo (ODGP,E.coli = 0.18±0.4; ODGP+CP,E.coli = 0.13±0.3; p≤0.0002; N≥7-8). An increase in osteoblast-mediated mineralisation was observed on all surfaces tested compared to CoCrMo. Furthermore, GP and GP+CP coated samples showed a statistically significant increase (MGP = 0.21±0.1; MGP+CP = 0.25±0.2; p<0.0001; N≥3-6).The preliminary data indicates that the gentamicin containing surfaces have the most effective antibacterial property and the highest osseointegrative capacity. The use of antibiotic coatings on prostheses could reduce the risk of PJI while being applied on osseointegrative implant surfaces.

Non-destructive processing of silver containing glass ceramic antibacterial coating on polymeric surgical mesh surfaces.

Surgical meshes composed of bioinert polymers such as polypropylene are widely used in millions of hernia repair procedures to prevent the recurrence of organ protrusion from the damaged abdominal wall. However, post-operative mesh infection remains a significant complication, elevating hernia recurrence risks from 3.6% to 10%, depending on the procedure type. While attempts have been made to mitigate these infection-related complications by using antibiotic coatings, the rise in antibiotic-resistant bacterial strains threatens their effectiveness. Bioactive glass-ceramics featuring noble metals, notably silver nanoparticles (AgNPs), have recently gained traction for their wide antibacterial properties and biocompatibility. Yet, conventional methods of synthesizing and coating of such materials often require high temperatures, thus making them impractical to be implemented on temperature-sensitive polymeric substrates. To circumvent this challenge, a unique approach has been explored to deposit these functional compounds onto temperature-sensitive polypropylene mesh (PP-M) surfaces. This approach is based on the recent advancements in cold atmospheric plasma (CAP) assisted deposition of SiO2 thin films and laser surface treatment (LST), enabling the selective heating and formation of functional glass-ceramic compounds under atmospheric conditions. A systematic study was conducted to identify optimal LST conditions that resulted in the effective formation of a bioactive glass-ceramic structure without significantly altering the chemical and mechanical properties of the underlying PP-M (less than 1% change compared to the original properties). The developed coating with optimized processing conditions demonstrated high biocompatibility and persistent antibacterial properties (>7 days) against both Gram-positive and Gram-negative bacteria. The developed process is expected to provide a new stepping stone towards depositing a wide range of functional bioceramic coatings onto different implant surfaces, thereby decreasing their risk of infection and associated complications.

Novel dalbavancin-PLLA implant coating prevents hematogenous Staphylococcus aureus infection in a minimally invasive mouse tail vein model.

Infective/bacterial endocarditis is a rare but life-threatening disease with a hospital mortality rate of 22.7% and a 1-year mortality rate of 40%. Therefore, continued research efforts to develop efficient anti-infective implant materials are of the utmost importance. Equally important is the development of test systems that allow the performance of new materials to be comprehensively evaluated. In this study, a novel antibacterial coating based on dalbavancin was tested in comparison to rifampicin/minocycline, and the suitability of a recently developed mouse tail vein model for testing the implant coatings was validated. Small polymeric stent grafts coated with a poly-L-lactic acid (PLLA) layer and incorporated antibiotics were colonized with Staphylococcus (S.) aureus before implantation into the tail vein of mice. The main assessment criteria were the hematogenous spread of the bacteria and the local tissue reaction to the contaminated implant. For this purpose, colony-forming units (CFU) in the blood, spleen and kidneys were determined. Tail cross sections were prepared for histological analysis, and plasma cytokine levels and expression values of inflammation-associated genes were examined. Both antibiotic coatings performed excellently, preventing the onset of infection. The present study expands the range of available methods for testing the anti-infectivity of cardiovascular implants, and the spectrum of agents for effective surface coating.

Implant surface modifications as a prevention method for periprosthetic joint infection caused by Staphylococcus aureus: a systematic review and meta-analysis.

Background: Periprosthetic joint infection is the most common infection due to joint replacement. It has been reported that, over a 5-year time span, 3.7 % of cases occurred annually. This statistic has increased to 6.86 % over 16years. Thus, an effective method is required to reduce these complications. Several strategies such as coating methods with various materials, such as antibiotics, silver, and iodine, have been reported. However, the best preventive strategy is still undetermined. Therefore, this systematic review aims to evaluate the outcome of coating methods on joint arthroplasty as a treatment or preventive management for infection complications. Methods: Eligible articles were systematically searched from multiple electronic databases (PubMed, Cochrane library, and ScienceDirect) up to 2June2022. Based on the criterion inclusion, eight articles were selected for this study. The Newcastle-Ottawa scale (NOS) was used to assess the quality of the study, and the meta-analysis test was conducted with Review Manager 5.4. Results: The quality of the articles in this study is in the range of moderate to good. It was found that the application of modified antibiotic coatings significantly reduced the occurrence of periprosthetic joint infection (PJI) ( 0.03), and silver coating could not significantly ( 0.47) prevent the occurrence of PJI. However, according to the whole aspect of coating modification, the use of antibiotics, silver, and iodine can minimize the occurrence of PJI ( ). Conclusion: Coating methods using antibiotics are an effective method that could significantly prevent the occurrence of PJI. On the other hand, coating with non-antibiotic materials such as silver could not significantly prevent the incidence of PJI.

Non-antibiotic antimicrobial polydopamine surface coating to prevent stable biofilm formation on satellite telemetry tags used in cetacean conservation applications

Satellite telemetry tags, used to monitor the migratory behavior of cetaceans, have the potential to be a vehicle for infection due to their invasive nature. Antibiotic coatings have been previously employed to reduce the chances of infection via the formation of a stable biofilm on the surface of the tags. However, increased use of antibiotics has the potential to lead to the development of antibiotic-resistant pathogens. To prevent the formation of antibiotic-resistant pathogens, a polydopamine surface coating that, when exposed to oxygen, releases low doses (~40-100µM) of hydrogen peroxide over a prolonged period (>24 hours) can be used to replace current antibiotic coatings used in the field. These pDA coatings can reduce bacterial adhesion from model bacteria from the two most common genotypes found on the skin of cetaceans (Psychrobacter and Tenacibaculum). The adhesion of Psychrobacter bacteria was reduced by 80% (p<0.01) while Tenacibaculum was reduced by 70% (p<0.001). When the bacteria were dosed with a non-lethal quantity of hydrogen peroxide (200µM) prior to being exposed to pDA surface coatings, there was no decrease in the efficacy of the coatings. This indicates a resistance to hydrogen peroxide will not be formed quickly. Overall, the polydopamine surface coatings were able to reduce the adhesion of model bacteria strains on the surface of medical grade stainless steel, which could increase the functional tag service life while reducing the chances of infection.

Contact Dermatitis in the Surgical Patient: A Focus on Wound Closure Materials.

Irritant and allergic contact dermatitis from wound closure materials can occur in patients after surgical procedures. The resulting inflammation from contact dermatitis can compromise wound healing, mimic surgical site infections, and result in wound dehiscence. Components of wound closure material, such as antibiotic coatings, dyes, sterilizing compounds, or the material itself, have been implicated as contact allergens. This article provides the latest overview of the components of 3 major forms of wound closure materials-sutures, staples, and tissue adhesives-associated with contact dermatitis, discusses their cross-reactivity, and provides diagnostic and treatment guidelines.

Mesoporous Silk-Bioactive Glass Nanocomposites as Drug Eluting Multifunctional Conformal Coatings for Improving Osseointegration and Bactericidal Properties of Metal Implants.

Endowing metal implants with multifunctional traits to prevent implant-associated infections and improve osseointegration has become a pivotal facet in orthopedics and dental fixation. Herein, we report the synthesis of mesoporous 70S bioactive glass-silk fibroin nanocomposites inspired by the biomimetic organo-apatites of mineralized collagen. The mesoporous, biomimetic nanocomposites enabled loading of antibiotics (gentamicin and doxycycline) and favored their release in a rapid manner while preserving their bioactivity. Ease in modification of the mesoporous nanocomposites enabled tailoring of 3-(aminopropyl)-triethoxysilane to the silanol network of bioactive glass, which improved the loading capacity of the hydrophobic drug (dexamethasone). The modification favored the slow and sustained release of dexamethasone from the modified mesoporous nanocomposites, which is desired for mediating osteogenesis and immunomodulation. Conformal coatings of these drug-loaded nanocomposites were materialized on stainless-steel implants through a facile electrophoretic deposition (EPD) technique, wherein the deposition yield can be controlled by applied parameters. Antibiotic coatings exhibited antibacterial efficacy with bioactivity retained up to 28 days, while dexamethasone-loaded coatings favored mesenchymal stem cell adhesion and osteoinduction. The immunomodulatory roles were also ascertained, wherein M2 macrophage biasness was favored in dexamethasone-loaded coatings. The versatility of these mesoporous biomimetic nanocomposites guarantee the loading of scenario-specific drugs to aid their local delivery through the conformal EPD coatings developed over metal implants toward improving implant patency.

Comparable Studies on Nanoscale Antibacterial Polymer Coatings Based on Different Coating Procedures.

The antibacterial activity of different antibiotic and metal-free thin polymer coatings was investigated. The films comprised quaternary ammonium compounds (QAC) based on a vinyl benzyl chloride (VBC) building block. Two monomeric QAC of different alkyl chain lengths were prepared, and then polymerized by two different polymerization processes to apply them onto Ti surfaces. At first, the polymeric layer was generated directly on the surface by atom transfer radical polymerization (ATRP). For comparison purposes, in a classical route a copolymerization of the QAC-containing monomers with a metal adhesion mediating phosphonate (VBPOH) monomers was carried out and the Ti surfaces were coated via drop coating. The different coatings were characterized by X-ray photoelectron spectroscopy (XPS) illustrating a thickness in the nanomolecular range. The cytocompatibility in vitro was confirmed by both live/dead and WST-1 assay. The antimicrobial activity was evaluated by two different assays (CFU and BTG, resp.,), showing for both coating processes similar results to kill bacteria on contact. These antibacterial coatings present a simple method to protect metallic devices against microbial contamination.

Microorganism Profiles of Penile Prosthesis Removed for Infection, Erosion, and Mechanical Malfunction Based on Next-Generation Sequencing

Next-generation sequencing (NGS) is an emerging technology that may allow for more sensitive and sophisticated microbial testing of the microbiota of penile prostheses (PP). To describe the microorganism profiles of PP explanted for infection, erosion, and mechanical malfunction using NGS. All patients who underwent PP removal by two physicians at two institutions were identified. Differences in alpha diversity (ie, number of species detected, species diversity across samples) and microbiome compositional profiles (Bray-Curtis community dissimilarities) across samples were assessed using ANOVA and PERMANOVA, respectively. Number of species detected, species diversity across samples, and microbiome compositional profiles. A total of 83 patients who underwent device removal for infection (n = 8, 10%), erosion (n = 5, 6%), and mechanical malfunction (n = 70, 84%) were included. When considering all devices, 56% (n = 48) of NGS and 29% (n = 24) of standard cultures resulted positive for presence of microorganisms. Culture only detected the most abundant NGS species in 62.5% (n = 5) of infected devices. Species richness and microbiome compositional profiles varied by surgical indication, but not by age, race, diabetes status, or implant duration. Most frequent organisms by surgical indication were Pseudomonas aeruginosa (infection), Staphylococcus epidermidis (erosion), and Escherichia coli (mechanical malfunction). The highest relative abundance organisms were P aeruginosa (infection), Corynebacterium jeikeium (erosion), and E coli (mechanical malfunction). Identifying microbiome profiles of PP removed for infection, erosion, and mechanical malfunction may guide the selection of peri-operative antibiotics and PP antibiotic coatings or hydrophilic dip solutions for each individual scenario. While this is the first study to utilize next-generation sequencing to evaluate penile prosthesis biofilm, the clinical significance of these findings has yet to be determined. A prospective, randomized trial aimed at evaluating the clinical significance of NGS in patients with PP infection is currently underway. NGS testing identified distinct microbiome profiles of PP removed for infection, erosion, and mechanical malfunction.

MP35-10 NEXT-GENERATION SEQUENCING APPEARS TO RECHARACTERIZE BIOFILM FROM INFECTED PENILE IMPLANTS: HAVE WE BEEN WRONG?

You have accessJournal of UrologyInfections/Inflammation/Cystic Disease of the Genitourinary Tract: Prostate & Genitalia (MP35)1 Sep 2021MP35-10 NEXT-GENERATION SEQUENCING APPEARS TO RECHARACTERIZE BIOFILM FROM INFECTED PENILE IMPLANTS: HAVE WE BEEN WRONG? Paul H. Chung, Erica Mann, Joon Yau Leong, and Gerald Henry Paul H. ChungPaul H. Chung More articles by this author , Erica MannErica Mann More articles by this author , Joon Yau LeongJoon Yau Leong More articles by this author , and Gerald HenryGerald Henry More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002044.10AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Next-generation sequencing (NGS) may provide deeper insight into the biofilm of infected penile implants. Historically, gram-positive skin organisms were most commonly thought to contribute to implant infection. We hypothesize that biofilm detected on penile implants removed due to infection constitute different organisms than those on devices removed for mechanical failure. METHODS: An IRB-approved retrospective review was performed of patients who underwent penile implant removal at two institutions. At time of explant, devices were swabbed with sterile gauze which was sent for NGS testing. Molecular testing of 16s ribosomal RNA was performed by NGS using an Illumina MiSeq sequencing platform (San Diego, CA). Variable regions 1-2 of 16S rDNA gene were amplified and prepared into libraries for sequencing using primers 28F and 388R. Organisms present at <2.0% abundance were considered rare and not included in summary analyses. RESULTS: 95 total implants were evaluated and 52 met study criteria (14 for infection, 38 for mechanical failure). The most prevalent five organisms from each device were assessed. Escherichia coli was one of the top five most abundant organisms of infected and non-infected devices. The other most prevalent organisms on infected devices were Pseudomonas aeruginosa, Enterococcus faecalis, Aerococcus urinae, and Corynebacterium jeikeium. On devices removed for mechanical failure, they were Cutibacterium acnes, Finegoldia magna, Staphylococcus epidermidis, and Burkholderia cepacia. Of the top seven most prevalent genus on implants removed for infection, the ratio of gram positive:gram negative was 5:2 and for devices removed for mechanical indications was 4:3. Common implant antibiotic coatings and dip combinations were broadly reviewed and had similar challenges covering bacteria identified with gentamycin and vancomycin providing the best coverage. CONCLUSIONS: Penile implants removed for infection versus mechanical failure were more pathogenic with organisms different than historically understood. Additional studies will help to further characterize differences and establish whether common antibiotic combinations for prophylaxis, irrigation, and implant coatings should be altered. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e630-e631 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Paul H. Chung More articles by this author Erica Mann More articles by this author Joon Yau Leong More articles by this author Gerald Henry More articles by this author Expand All Advertisement Loading ...

Toward Bactericidal Enhancement of Additively Manufactured Titanium Implants

Implant-associated infections (IAIs) are among the most intractable and costly complications in implant surgery. They can lead to surgery failure, a high economic burden, and a decrease in patient quality of life. This manuscript is devoted to introducing current antimicrobial strategies for additively manufactured (AM) titanium (Ti) implants and fostering a better understanding in order to pave the way for potential modern high-throughput technologies. Most bactericidal strategies rely on implant structure design and surface modification. By means of rational structural design, the performance of AM Ti implants can be improved by maintaining a favorable balance between the mechanical, osteogenic, and antibacterial properties. This subject becomes even more important when working with complex geometries; therefore, it is necessary to select appropriate surface modification techniques, including both topological and chemical modification. Antibacterial active metal and antibiotic coatings are among the most commonly used chemical modifications in AM Ti implants. These surface modifications can successfully inhibit bacterial adhesion and biofilm formation, and bacterial apoptosis, leading to improved antibacterial properties. As a result of certain issues such as drug resistance and cytotoxicity, the development of novel and alternative antimicrobial strategies is urgently required. In this regard, the present review paper provides insights into the enhancement of bactericidal properties in AM Ti implants.

147 An Evaluation of Penile Implant Biofilms using Next Generation DNA Sequencing: Is there a difference in Diabetic Patients?

Next-generation sequencing (NGS) may offer a more comprehensive assessment of penile implant biofilm compared to conventional culture. Improved characterization of biofilms using NGS may provide insight as to how infections may be reduced by potentially guiding tailored antibiotic prophylaxis, antibiotic irrigation, or implant antibiotic coatings. We hypothesize that penile implant biofilm differs between diabetic (DM) and non-DM patients because of the potentially immunocompromised nature of DM patients.

Controlled Release of Vancomycin and Tigecycline from an Orthopaedic Implant Coating Prevents Staphylococcus aureus Infection in an Open Fracture Animal Model

Introduction Treatment of open fractures routinely involves multiple surgeries and delayed definitive fracture fixation because of concern for infection. If implants were made less susceptible to infection, a one-stage procedure with intramedullary nailing would be more feasible, which would reduce morbidity and improve outcomes. Methods In this study, a novel open fracture mouse model was developed using Staphylococcus aureus (S. aureus) and single-stage intramedullary fixation. The model was used to evaluate whether implants coated with a novel “smart” polymer coating containing vancomycin or tigecycline would be colonized by bacteria in an open fracture model infected with S. aureus. In vivo bioluminescence, ex vivo CFUs, and X-ray images were evaluated over a 42-day postoperative period. Results We found evidence of a markedly decreased bacterial burden with the local release of vancomycin and tigecycline from the PEG-PPS polymer compared to polymer alone. Vancomycin was released in a controlled fashion and maintained local drug concentrations above the minimum inhibition concentration for S. aureus for greater than 7 days postoperatively. Bacteria were reduced 139-fold from implants containing vancomycin and undetected from the bone and soft tissue. Tigecycline coatings led to a 5991-fold reduction in bacteria isolated from bone and soft tissue and 15-fold reduction on the implants compared to polymer alone. Antibiotic coatings also prevented osteomyelitis and implant loosening as observed on X-ray. Conclusion Vancomycin and tigecycline can be encapsulated in a polymer coating and released over time to maintain therapeutic levels during the perioperative period. Our results suggest that antibiotic coatings can be used to prevent implant infection and osteomyelitis in the setting of open fracture. This novel open fracture mouse model can be used as a powerful in vivo preclinical tool to evaluate and optimize the treatment of open fractures before further studies in humans.

Robust Low Friction Antibiotic Coating of Urethral Catheters Using a Catechol-Functionalized Polymeric Hydrogel Film

Indwelling urethral catheters are widely used in hospitalized patients however they are associated with bacterial infection and biofilm formation due to the suboptimal surface properties of the elastic materials used for the catheters. Although there are several antibacterial coating technologies to modify the surface properties of the catheter including hydrophilic polymeric coating, the risk of infection is still high given the absence of reactive functional groups on the surface of elastomers. In this study, we describe the use of catechol-functionalized hydrophilic polymers and explore strategies to create antibacterial hydrogel coatings. Three different types of catechol-functionalized polymers, chitosan, hyaluronic acid, and human serum albumin were synthesized and deposited using simple dip-coating method. All of the tested polymers could coat different types of elastomers widely used for urethral catheters independent to the surface properties, and the thickness of the coating could be controlled by the number of depositions. The coating formed stable water-containing lubricant surface beneficial as a physical repellant of microbial attachment. In addition, the coating could be combined with additional antibacterial agents such as silver nanoparticles to maximize the antibacterial effect on the surface of urethral catheter materials.

The Effect of Bupivacaine on the Efficacy of Antibiotic Coating on Penile Implants in Preventing Infection.

BackgroundIn an effort to reduce dependence on opioids following inflatable penile prosthesis placement, intra-operative soaking of the implant in Bupivacaine (BUP) has been proposed as part of a multimodal approach to pain control. However, no study has shown if the addition of BUP affects the antimicrobial properties of InhibiZone on AMS700 (Boston Scientific, Marlborough, MA) and/or of antibiotic soaked Titan Coloplast (Coloplast Corporation, Minneapolis, MN).AimTo determine if BUP alters the zone of inhibition (ZOI) against Staphylococcus epidermidis (S epidermidis) and Escherichia coli (E coli), common gram-positive and gram-negative bacterial causes of infection, respectively, created by InhibiZone coated AMS and/or by antibiotic-soaked Coloplast implant.MethodsS epidermidis and E coli were spread on agar plates. After a 30-minute incubation, four AMS with InhibiZone strips treated with sterile saline or BUP (1.25 mg/mL) were placed on a plate. 4 Coloplast strips were dipped in varying routinely used concentrations of Rifampin (0–10 mg/mL) plus Gentamicin (0–1 mg/mL; rifampin and gentamicin (R+G)) solution with or without BUP. The ZOI for AMS with InhibiZone and Coloplast dipped in antibiotic solution was measured using ImageJ software. Normalized ZOI was calculated as (ZOI area/plate area) × 100. Unpaired t-test compared the mean ± SD ZOI between BUP and no BUP groups (n = 4/group).OutcomesThe primary outcome of the study was the ZOI against E coli and S epidermidis at 24 and 48 hours.ResultsGrowth of both S epidermidis and E coli at 24 and 48 hours of incubation was inhibited in both implants and the addition of BUP did not alter the ZOI. Coloplast strips dipped in R+G produced a ZOI in a dose-dependent manner. Interestingly, the ZOI against S epidermidis compared to that of E coli was much wider for both implants.Clinical ImplicationsThis suggests that the use of BUP does not affect the protective effects of antibiotic dips and can potentially be used during penile prosthesis surgery pending clinical trials.Strengths and LimitationsThis is the first study to evaluate the effect of BUP on anti-bacterial dips. As with all in vitro analysis, further research must be done to see if these findings hold true in the clinical setting.ConclusionsThe addition of BUP does not impede the in vitro antibacterial activity of InhibiZone-coated AMS or R+G-soaked Coloplast. Whether these in vitro findings translate to surgical outcomes needs to be evaluated in future preclinical trials.Lokeshwar SD, Horodyski L, Lahorewala SS, et al. The Effect of Bupivacaine on the Efficacy of Antibiotic Coating on Penile Implants in Preventing Infection. J Sex Med 2019;7:337−344.

In vivo analysis of a first-in-class tri-alkyl norspermidine-biaryl antibiotic in an active release coating to reduce the risk of implant-related infection

Prosthetic joint infection (PJI) is a well-known and persisting problem. Active release coatings have promise to provide early protection to an implant by eradicating small colony biofilm contaminants or planktonic bacteria that can form biofilm. Traditional antibiotics can be limited as active release agents in that they have limited effect against biofilms and develop resistance at sub-lethal concentrations. A unique first-in-class compound (CZ-01127) was assessed as the active release agent in a silicone (Si)-based coating to prevent PJI in a sheep model of joint space infection. Titanium (Ti) plugs contained a porous coated Ti (PCTi) region and polymer-coated region. Plugs were implanted into a femoral condyle of sheep to assess the effect of the Si polymer on cancellous bone ingrowth, the effect of CZ-01127 on bone ingrowth, and the ability of CZ-01127 to prevent PJI. Microbiological results showed that CZ-01127 was able to eradicate bacteria in the local region of the implanted plugs. Data further showed that Si did not adversely affect bone ingrowth. However, bacteria that reached the joint space (synovium) were not fully eradicated. Outcomes suggested that the CZ-01127 coating provided local protection to the implant system in a challenging model, the design of which could be beneficial for testing future antimicrobial therapies for PJI. Statement of SignificancePeriprosthetic joint infection (PJI) is now commonplace, and constitutes an underlying problem that patients and physicians face. Active release antibiotic coatings have potential to prevent these infections. Traditional antibiotics are limited in their ability to eradicate bacteria that reside in biofilms, and are more susceptible to resistance development. This study addressed these limitations by testing the efficacy of a unique antimicrobial compound in a coating that was tested in a challenging sheep model of PJI. The unique coating was able to eradicate bacteria and prevent infection in the environment adjacent to the implant. Bacteria that escaped into the joint space still caused infection, yet benchmark data can be used to optimize the coating and translate it toward clinical use.

Re: Antibiotic Coating of the Artificial Urinary Sphincter (AMS 800): Is it Worthwhile?

Re: Antibiotic Coating of the Artificial Urinary Sphincter (AMS 800): Is it Worthwhile?

Antibacterial and immunogenic behavior of silver coatings on additively manufactured porous titanium

Implant-associated infections (IAI) are often recurrent, expensive to treat, and associated with high rates of morbidity, if not mortality. We biofunctionalized the surface of additively manufactured volume-porous titanium implants using electrophoretic deposition (EPD) as a way to eliminate the peri-operative bacterial load and prevent IAI. Chitosan-based (Ch) coatings were incorporated with different concentrations of silver (Ag) nanoparticles or vancomycin. A full-scale in vitro and in vivo study was then performed to evaluate the antibacterial, immunogenic, and osteogenic activity of the developed implants. In vitro, Ch + vancomycin or Ch + Ag coatings completely eliminated, or reduced the number of planktonic and adherent Staphylococcus aureus by up to 4 orders of magnitude, respectively. In an in vivo tibia intramedullary implant model, Ch + Ag coatings caused no adverse immune or bone response under aseptic conditions. Following Staphylococcus aureus inoculation, Ch + vancomycin coatings reduced the implant infection rate as compared to chitosan-only coatings. Ch + Ag implants did not demonstrate antibacterial effects in vivo and even aggravated infection-mediated bone remodeling including increased osteoclast formation and inflammation-induced new bone formation. As an explanation for the poor antibacterial activity of Ch + Ag implants, it was found that antibacterial Ag concentrations were cytotoxic for neutrophils, and that non-toxic Ag concentrations diminished their phagocytic activity. This study shows the potential of EPD coating to biofunctionalize porous titanium implants with different antibacterial agents. Using this method, Ag-based coatings seem inferior to antibiotic coatings, as their adverse effects on the normal immune response could cancel the direct antibacterial effects of Ag nanoparticles. Statement of SignificanceImplant-associated infections (IAI) are a clinical, societal, and economical burden. Surface biofunctionalization approaches can render complex metal implants with strong local antibacterial action. The antibacterial effects of inorganic materials such as silver nanoparticles (Ag NPs) are often highlighted under very confined conditions in vitro. As a novelty, this study also reports the antibacterial, immunogenic, and osteogenic activity of Ag NP-coated additively-manufactured titanium in vivo. Importantly, it was found that the developed coatings could impair the normal function of neutrophils, the most important phagocytic cells protecting us from IAI. Not surprisingly, the Ag NP-based coatings were outperformed by an antibiotic-based coating. This emphasizes the importance of also targeting implant immune-modulatory functions in future coating strategies against IAI.