Preventing Staphylococci Surgical Site Infections with a Nitric Oxide-Releasing Poly(lactic acid-co-glycolic acid) Suture Material.

Of the 27 million surgeries performed in the United States each year, a reported 2.6% result in a surgical site infection (SSI), and Staphylococci species are commonly the culprit. Alternative therapies, such as nitric oxide (NO)-releasing biomaterials, are being developed to address this issue. NO is a potent antimicrobial agent with several modes of action, including oxidative and nitrosative damage, disruption of bacterial membranes, and dispersion of biofilms. For targeted antibacterial effects, NO is delivered by exogenous donor molecules, like S-nitroso-N-acetylpenicillamine (SNAP). Herein, the impregnation of SNAP into poly(lactic-co-glycolic acid) (PLGA) for SSI prevention is reported for the first time. The NO-releasing PLGA copolymer is fabricated and characterized by donor molecule loading, leaching, and the amount remaining after ethylene oxide sterilization. The swelling ratio, water uptake, static water contact angle, and tensile strength are also investigated. Furthermore, its cytocompatibility is tested against 3T3 mouse fibroblast cells, and its antimicrobial efficacy is assessed against multiple Staphylococci strains. Overall, the NO-releasing PLGA copolymer holds promise as a suture material for eradicating surgical site infections caused by Staphylococci strains. SNAP impregnation affords robust antibacterial properties while maintaining the cytocompatibility and mechanical integrity.

Development and cross-validation of simple HPLC-fluorescence and UPLC-MS-UV methods for rapid determination of oleuropein in olive leaves.

INTRODUCTION: Olive leaves, abundant by-products of the olive oil industry, are a rich source of oleuropein, an important polyphenol in olive leaves. So far, no published methods have been validated using matrix standards for oleuropein quantification in olive leaves. OBJECTIVES: The study aimed to develop an HPLC method for oleuropein determination in olive leaves using spiked matrix standards prepared from a blank olive leaf matrix, to validate the method with respect to aqueous standards, and cross-validate the HPLC method with UPLC-MS and UPLC-UV techniques. METHODOLOGY: Oleuropein was extracted into methanol and analysed by HPLC with fluorescence detection (FLD; excitation and emission wavelengths 281 and 316 nm, respectively) and by UPLC-MS-UV. For validation, calibration curves of spiked matrix standards (0.4 to 4.8 mg/g) were analysed by the three methods over several days. Oleuropein was then analysed in French olive varieties. RESULTS: For the HPLC-FLD method, repeatability and intermediate precision were less than 5% RSD and linearity was demonstrated by the Fischer test. Differences in results of the spiked placebos by the three methods were non-significant, as confirmed by ANOVA. Extraction recovery was >90%, and there was a strong linear relationship between authentic and spiked matrix standards. The determination of oleuropein in French olive varieties is reported, including analysis in "Olivière" cultivar for the first time, leaves of which contained twice the amount of oleuropein compared with "Picholine". CONCLUSION: Accurate quantification of oleuropein is possible using aqueous standards. Cross-validation indicates that selective analysis can equally be carried out by HPLC or by UPLC-MS techniques.

Antimicrobial efficacy of a nitric oxide-releasing ampicillin conjugate catheter lock solution on clinically-isolated antibiotic-resistant bacteria.

Antibiotic lock therapy (ALT) is standard clinical practice for treating bacteremia linked with catheter-related bloodstream infections (CRBSIs). However, this strategy frequently fails against multi-drug-resistant bacteria in clinical settings. In this study, a novel approach to utilize a nitric oxide (NO) donor S-nitroso-N-acetyl-penicillamine (SNAP)-conjugated to ampicillin antibiotic (namely SNAPicillin) as a catheter lock solution is presented. The conjugate of two antimicrobial agents is anticipated to overcome the challenges of bacterial infection caused by antibiotic-resistant bacteria in ALT applications. Nitric oxide release from the SNAPicillin lock solution at varying concentrations was measured at 0 and 24 h time points in a catheter model system, which revealed tunable NO release at physiological levels. The clinical strains of E. coli (CDC AR-0089) and S. marcescens (CDC AR-0099) were screened using a zone of inhibition assay against standard antibiotics which confirmed the antibiotic resistance in bacteria. The minimum inhibitory concentration (MIC) testing of SNAPicillin unveiled the lowest MIC value for SNAPicillin against both E. coli and S. marcescens (1 and 2 mM of SNAPicillin, respectively) with an 8.24- and 4.28-log reduction in bacterial load compared to controls, respectively. In addition, while the ampicillin-treated biofilm demonstrated resistance toward the antibiotic, SNAPicillin led to >99% reduction in exterminating biofilm buildup on polymeric catheter surfaces. Lastly, the SNAPicillin lock solution was determined to be biocompatible via hemolysis and cell compatibility studies. Together, these results emphasize the promising potential of SNAPicillin lock solution with the dual-action of NO and ampicillin in overcoming bacterial challenges on medical devices like central venous catheters and other medical device interfaces.

Biomimetic gasotransmitter-releasing alginate beads for biocompatible antimicrobial therapy.

HYPOTHESIS: Alginate is widely used in biomedical applications due to its high biocompatibility as well as structural and mechanical similarities to human tissue. Further, simple ionic crosslinking of alginate allows for the formation of alginate beads capable of drug delivery. S-nitrosoglutathione is a water-soluble molecule that releases nitric oxide in physiological conditions, where it acts as a potent antimicrobial gas, among other functions. As macrophages and endothelial cells endogenously produce nitric oxide, incorporating nitric oxide donors into polymers and hydrogels introduces a biomimetic approach to mitigate clinical infections, including those caused by antibiotic-resistant microorganisms. The incorporation of S-nitrosoglutathione into macro-scale spherical alginate beads is reported for the first time and shows exciting potential for biomedical applications. EXPERIMENTS: Herein, nitric oxide-releasing crosslinked alginate beads were fabricated and characterized for surface and cross-sectional morphology, water uptake, size distribution, and storage stability. In addition, the NO release was quantified by chemiluminescence and its biological effects against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus were investigated. The biocompatibility of the alginate beads was tested against 3T3 mouse fibroblast cells. FINDINGS: Overall, nitric oxide-releasing alginate beads demonstrate biologically relevant activities without eliciting a cytotoxic response, revealing their potential use as an antimicrobial material with multiple mechanisms of bacterial killing.

Improved Polymer Hemocompatibility for Blood-Contacting Applications via S-Nitrosoglutathione Impregnation.

Blood-contacting medical devices (BCMDs) are inevitably challenged by thrombi formation, leading to occlusion of flow and device failure. Ideal BCMDs seek to mimic the intrinsic antithrombotic properties of the human vasculature to locally prevent thrombotic complications, negating the need for systemic anticoagulation. An emerging category of BCMD technology utilizes nitric oxide (NO) as a hemocompatible agent, as the vasculature's endothelial layer naturally releases NO to inhibit platelet activation and consumption. In this paper, we report for the first time the novel impregnation of S-nitrosoglutathione (GSNO) into polymeric poly(vinyl chloride) (PVC) tubing via an optimized solvent-swelling method. Material testing revealed an optimized GSNO-PVC material that had adequate GSNO loading to achieve NO flux values within the physiological endothelial NO flux range for a 4 h period. Through in vitro hemocompatibility testing, the optimized material was deemed nonhemolytic (hemolytic index <2%) and capable of reducing platelet activation, suggesting that the material is suitable for contact with whole blood. Furthermore, an in vivo 4 h extracorporeal circulation (ECC) rabbit thrombogenicity model confirmed the blood biocompatibility of the optimized GSNO-PVC. Platelet count remained near 100% for the novel GSNO-impregnated PVC loops (1 h, 91.08 ± 6.27%; 2 h, 95.68 ± 0.61%; 3 h, 97.56 ± 8.59%; 4 h, 95.11 ± 8.30%). In contrast, unmodified PVC ECC loops occluded shortly after the 2 h time point and viable platelet counts quickly diminished (1 h, 85.67 ± 12.62%; 2 h, 54.46 ± 10.53%; 3 h, n/a; 4 h, n/a). The blood clots for GSNO-PVC loops (190.73 ± 72.46 mg) compared to those of unmodified PVC loops (866.50 ± 197.98 mg) were significantly smaller (p < 0.01). The results presented in this paper recommend further investigation in long-term animal models and suggest that GSNO-PVC has the potential to serve as an alternative to systemic anticoagulation in BCMD applications.

Development of a Credible Virtual Clinician Promoting Colorectal Cancer Screening via Telehealth Apps for and by Black Men: Qualitative Study.

BACKGROUND: Traditionally, promotion of colorectal cancer (CRC) screening among Black men was delivered by community health workers, patient navigators, and decision aids (printed text or video media) at clinics and in the community setting. A novel approach to increase CRC screening of Black men includes developing and utilizing a patient-centered, tailored message delivered via virtual human technology in the privacy of one's home. OBJECTIVE: The objective of this study was to incorporate the perceptions of Black men in the development of a virtual clinician (VC) designed to deliver precision messages promoting the fecal immunochemical test (FIT) kit for CRC screening among Black men in a future clinical trial. METHODS: Focus groups of Black men were recruited to understand their perceptions of a Black male VC. Specifically, these men identified source characteristics that would enhance the credibility of the VC. The modality, agency, interactivity, and navigability (MAIN) model, which examines how interface features affect the user's psychology through four affordances (modality, agency, interactivity, and navigability), was used to assess the presumed credibility of the VC and likability of the app from the focus group transcripts. Each affordance triggers heuristic cues that stimulate a positive or a negative perception of trustworthiness, believability, and understandability, thereby increasing source credibility. RESULTS: In total, 25 Black men were recruited from the community and contributed to the development of 3 iterations of a Black male VC over an 18-month time span. Feedback from the men enhanced the visual appearance of the VC, including its movement, clothing, facial expressions, and environmental surroundings. Heuristics, including social presence, novelty, and authority, were all recognized by the final version of the VC, and creditably was established. The VC was named Agent Leveraging Empathy for eXams (ALEX) and referred to as "brother-doctor," and participants stated "wanting to interact with ALEX over their regular doctor." CONCLUSIONS: Involving Black men in the development of a digital health care intervention is critical. This population is burdened by cancer health disparities, and incorporating their perceptions in telehealth interventions will create awareness of the need to develop targeted messages for Black men.

Surface-Catalyzed Nitric Oxide Release via a Metal Organic Framework Enhances Antibacterial Surface Effects.

It has been previously demonstrated that metal nanoparticles embedded into polymeric materials doped with nitric oxide (NO) donor compounds can accelerate the release rate of NO for therapeutic applications. Despite the advantages of elevated NO surface flux for eradicating opportunistic bacteria in the initial hours of application, metal nanoparticles can often trigger a secondary biocidal effect through leaching that can lead to unfavorable cytotoxic responses from host cells. Alternatively, copper-based metal organic frameworks (MOFs) have been shown to stabilize Cu2+/1+ via coordination while demonstrating longer-term catalytic performance compared to their salt counterparts. Herein, the practical application of MOFs in NO-releasing polymeric substrates with an embedded NO donor compound was investigated for the first time. By developing composite thermoplastic silicon polycarbonate polyurethane (TSPCU) scaffolds, the catalytic effects achievable via intrapolymeric interactions between an MOF and NO donor compound were investigated using the water-stable copper-based MOF H3[(Cu4Cl)3(BTTri)8-(H2O)12]·72H2O (CuBTTri) and the NO donor S-nitroso-N-acetyl-penicillamine (SNAP). By creating a multifunctional triple-layered composite scaffold with CuBTTri and SNAP, the surface flux of NO from catalyzed SNAP decomposition was found tunable based on the variable weight percent CuBTTri incorporation. The tunable NO surface fluxes were found to elicit different cytotoxic responses in human cell lines, enabling application-specific tailoring. Challenging the TSPCU-NO-MOF composites against 24 h bacterial growth models, the enhanced NO release was found to elicit over 99% reduction in adhered and over 95% reduction in planktonic methicillin-resistant Staphylococcus aureus, with similar results observed for Escherichia coli. These results indicate that the combination of embedded MOFs and NO donors can be used as a highly efficacious tool for the early prevention of biofilm formation on medical devices.

Association of teleworking and smoking behavior of U.S. wage and salary workers.

INTRODUCTION: The COVID-19 pandemic has led to a major shift in workspace from office to home. This report examined how telecommuting is related to smoking behavior of wage and salary workers. METHODS: Self-reported smoking behavior of 1,390 U.S. wage and salary workers aged 16-64 years from the Tobacco Use Supplement of the Current Population Survey 2018/19 were linked to the 2018 American Time Use Survey. Weighted multivariate logistic regression predicting smoking probability and generalized linear regression predicting smoking intensity were used for analysis. RESULTS: Almost a fifth (19%) of wage and salary workers reported working from home and over a half (52%) reported working in telecommuting amenable occupations. Nearly 12% were current smokers, smoking 14.7 cigarettes daily on average. Compared to their counterparts, smoking prevalence (percentage points) was lower among those employed in telecommuting amenable occupations (-0.52, p < .001 for all; 0.01, p = .862 for men; -2.40, p < .001 for women) and who worked more frequently from home (-0.21, p < .001 for all; -0.76, p < .001 for men; -0.03, p = .045 for women). Smoking intensity (cigarettes per day) was lower among those employed in telecommuting amenable occupations (-3.39, p = .03 for all; -0.36, p = .90 for men; -4.30, p = .21 for women). We found no statistically significant association between smoking intensity and telecommuting frequency. CONCLUSIONS: The lower likelihood of smoking and lower level of smoking intensity among telecommuting wage and salary workers suggests the need for proactive efforts to address the potential exacerbation in occupation-related smoking disparities between occupations that are and are not amenable to telecommuting.

A Synergistic New Approach Toward Enhanced Antibacterial Efficacy via Antimicrobial Peptide Immobilization on a Nitric Oxide-Releasing Surface.

Despite technological advancement, nosocomial infections are prevalent due to the rise of antibiotic resistance. A combinatorial approach with multimechanistic antibacterial activity is desired for an effective antibacterial medical device surface strategy. In this study, an antimicrobial peptide, nisin, is immobilized onto biomimetic nitric oxide (NO)-releasing medical-grade silicone rubber (SR) via mussel-inspired polydopamine (PDA) as a bonding agent to reduce the risk of infection. Immobilization of nisin on NO-releasing SR (SR-SNAP-Nisin) and the surface characteristics were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy and contact angle measurements. The NO release profile (7 days) and diffusion of SNAP from SR-SNAP-Nisin were quantified using chemiluminescence-based nitric oxide analyzers and UV-vis spectroscopy, respectively. Nisin quantification showed a greater affinity of nisin immobilization toward SNAP-doped SR. Matrix-assisted laser desorption/ionization mass spectrometry analysis on surface nisin leaching for 120 h under physiological conditions demonstrated the stability of nisin immobilization on PDA coatings. SR-SNAP-Nisin shows versatile in vitro anti-infection efficacy against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus in the planktonic and adhered states. Furthermore, the combination of NO and nisin has a superior ability to impair biofilm formation on polymer surfaces. SR-SNAP-Nisin leachates did not elicit cytotoxicity toward mouse fibroblast cells and human umbilical vein endothelial cells, indicating the biocompatibility of the material in vitro. The preventative and therapeutic potential of SR-SNAP-Nisin dictated by two bioactive agents may offer a promising antibacterial surface strategy.

Internet-based Tailored Virtual Human Health Intervention to Promote Colorectal Cancer Screening: Design Guidelines from Two User Studies.

To influence user behaviors, Internet-based virtual humans (VH) have been used to deliver health interventions. However, Internet-based VH health interventions face challenges. The challenges can affect user perceptions of an Internet-based VH health intervention. In our work, we use an Internet-based VH health intervention to promote colorectal cancer (CRC) screening. We present design guidelines drawn from two studies. The two studies examined the influence of visual design and the influence of the information medium on user intentions to pursue more health information. In the first study, the analysis of the focus group (n=73 users) transcripts shows that the VH's visual realism, the VH's healthcare role, and the presence of a local healthcare provider's logo influenced user perceptions of the VH-based intervention's visual design. The findings from the focus groups were used to iterate the intervention and derive design guidelines. In the second study (n=1,400), the analysis of online surveys of users after the VH-based intervention showed that very few users focused on the VH's appearance. To influence the user intentions to pursue the health topic further, the results recommend the use of an animated VH to deliver health information compared to other mediums of information delivery, such as text. The design guidelines from the two studies can be used by developers to use VH-based interventions to influence users' intention to change behaviors.

Tailoring virtual human-delivered interventions: A digital intervention promoting colorectal cancer screening for Black women.

OBJECTIVE: Despite efforts to reduce cancer disparities, Black women remain underrepresented in cancer research. Virtual health assistants (VHAs) are one promising digital technology for communicating health messages and promoting health behaviors to diverse populations. This study describes participant responses to a VHA-delivered intervention promoting colorectal cancer (CRC) screening with a home-stool test. METHODS: We recruited 53 non-Hispanic Black women 50 to 73 years old to participate in focus groups and think-aloud interviews and test a web-based intervention delivered by a race- and gender-concordant VHA. A user-centered design approach prioritized modifications to three successive versions of the intervention based on participants' comments. RESULTS: Participants identified 26 cues relating to components of the VHA's credibility, including trustworthiness, expertise, and authority. Comments on early versions revealed preferences for communicating with a human doctor and negative critiques of the VHA's appearance and movements. Modifications to specific cues improved the user experience, and participants expressed increased willingness to engage with later versions of the VHA and the screening messages it delivered. Informed by the Modality, Agency, Interactivity, Navigability Model, we present a framework for developing credible VHA-delivered cancer screening messages. CONCLUSIONS: VHAs provide a systematic way to deliver health information. A culturally sensitive intervention designed for credibility promoted user interest in engaging with guideline-concordant CRC screening messages. We present strategies for effectively using cues to engage audiences with health messages, which can be applied to future research in varying contexts.

Creating an mHealth App for Colorectal Cancer Screening: User-Centered Design Approach.

BACKGROUND: Patients are increasingly using mobile health (mHealth) apps to monitor their health and educate themselves about medical issues. Despite the increasing popularity of such apps, poor design and usability often lead to suboptimal continued use of these apps and subsequently to poor adherence to the behavior changes at which they are aimed. One solution to these design problems is for app developers to use user-centered design (UCD) principles to consider the context and needs of users during the development process. OBJECTIVE: This study aimed to present a case study on the design and development process for an mHealth app that uses virtual human technology (VHT) to encourage colorectal cancer (CRC) screening among patients aged 50 years and above. METHODS: We have first provided an overview of the project and discussed its utilization of VHT. We have then reviewed UCD principles and how they can be incorporated into the development of health apps. We have described how we used UCD processes during the app's development. We have then discussed the unique roles played by communication researchers, computer scientists, clinicians, and community participants in creating an mHealth app that is credible, usable, effective, and accessible to its target audience. RESULTS: The principles of UCD were woven throughout the project development, with researchers collecting feedback from patients and providers at all stages and using that feedback to improve the credibility, usability, effectiveness, and accessibility of the mHealth app. The app was designed in an iterative process, which encouraged feedback and improvement of the app and allowed teams from different fields to revisit topics and troubleshoot problems. CONCLUSIONS: Implementing a UCD process contributed to the development of an app, which not only reflected cross-disciplinary expertise but also the needs, wants, and concerns of patients.

Poor mobility in hospitalized adults of all ages.

Low levels of activity in hospital inpatients contribute to functional decline. Previous studies have shown low levels of activity in older inpatients, but few have investigated younger inpatients (aged <65 years). This observational study measured activity in older (aged ≥65 years) and younger hospital inpatients on 3 wards (medical, surgical, oncology) in a major teaching hospital in Brisbane, Australia, as part of a quality-improvement intervention to enhance mobility. Using structured behavioral mapping protocols, participants were observed for 2-minute intervals throughout 4, 4-hour daytime observation periods. The proportion of time spent at different activity levels was calculated for each participant, and time spent standing, walking or wheeling was compared between age group and wards. There were 3272 observations collected on 132 participants (median, 30 per patient; range, 9-35). The most time was spent lying in bed (mean 57%), with 9% standing or walking. There were significant differences among wards, but no difference between older and younger subgroups. Low mobility is common in adult inpatients of all ages. Behavioral mapping provided measures suitable for use in quality improvement.

CARES: improving the care and disposition of psychiatric patients in the pediatric emergency department.

OBJECTIVES: Pediatric psychiatric emergencies are a nationwide crisis and have contributed to an increase in behavioral health emergency department (ED) visits. A collaborative response to this crisis was the creation of the Child & Adolescent Rapid Emergency Stabilization (CARES) program. The objective of this study is to determine how the CARES unit influenced length of stay (LOS) and costs for psychiatric patients in the pediatric ED. METHODS: A retrospective review of ED patients was conducted. Children presenting 1 year before CARES, October 13, 2006, to October 13, 2007 (pre-CARES), were compared with 1 year after, October 15, 2007, to October 15, 2008 (post-CARES). The study population includes all patients presenting to the ED with psychiatric illnesses. The primary outcome is mean LOS in hours. Supplemental analyses of total charges, payments, and costs were performed. RESULTS: There were 1719 visits before and 1867 visits after CARES, with 1190 and 1273 unique patient visits, respectively. Children in both groups had similar age, gender, and ethnicity. Pre-CARES had a mean LOS of 19.7 hours (SD, 32.6), whereas post-CARES had 10.8 hours (SD, 19.9) (P < 0.0001). Evaluating only unique visits, the difference remained highly significant. Post-CARES, compared with pre-CARES, the average charge per patient decreased by $905 (P < 0.0001), average payment decreased by $111 (P < 0.06), and average total cost decreased by $569 or 38.7% (P < 0.0001). The total cost savings the year after CARES opened was $1,019,168.55.

Characterization of the spike protein of human coronavirus NL63 in receptor binding and pseudotype virus entry.

The spike (S) protein of human coronavirus NL63 (HCoV-NL63) mediates both cell attachment by binding to its receptor hACE2 and membrane fusion during virus entry. We have previously identified the receptor-binding domain (RBD) and residues important for RBD-hACE2 association. Here, we further characterized the S protein by investigating the roles of the cytoplasmic tail and 19 residues located in the RBD in protein accumulation, receptor binding, and pseudotype virus entry. For these purposes, we first identified an entry-efficient S gene template from a pool of gene variants and used it as a backbone to generate a series of cytoplasmic tail deletion and single residue substitution mutants. Our results showed that: (i) deletion of 18aa from the C-terminus enhanced the S protein accumulation and virus entry, which might be due to the deletion of intracellular retention signals; (ii) further deletion to residue 29 also enhanced the amount of S protein on the cell surface and in virion, but reduced virus entry by 25%, suggesting that residues 19-29 contributes to membrane fusion; (iii) a 29aa-deletion mutant had a defect in anchoring on the plasma membrane, which led to a dramatic decrease of S protein in virion and virus entry; (iv) a total of 15 residues (Y498, V499, V531, G534, G537, D538, S540, G575, S576, E582, W585, Y590, T591, V593 and G594) within RBD were important for receptor binding and virus entry. They probably form three receptor binding motifs, and the third motif is conserved between NL63 and SARS-CoV.