Incorporation of Gold Nanoparticles into the Bilayer of Polydiacetylene Unilamellar Vesicles\u3cem\u3e \u3c/em\u3e

Gold nanoparticles made with three different alkanethiol surface passivating agents were loaded into the hydrophobic bilayers of polydiacetylene liposomes. The physical and optical properties of the vesicles were compared to each other and a nanoparticle- free control. Small gold nanoparticles were utilized to minimize the plasmon absorption and thereby minimize the effects of energy transfer processes on the optical behavior of the polydiacetylene moiety. The size and structure of the liposomes were examined with dynamic light scattering and electron microscopy, while the stability of the bilayer was investigated through differential scanning calorimetry. Optical spectroscopy was used to monitor the photopolymerization of the vesicles as well as the stress-induced polydiacetylene blue to red transition. Specifically, changes to the absorption frequency, fluorescence frequency, and the fluorescence intensity were monitored. This system can serve as a model system for the optimization of liposomes containing nanoparticles with specialized optical, magnetic, or chemical functionality

SARS-CoV-2 Seroprevalence and Drug Use in Trauma Patients from Six Sites in the United States

In comparison to the general patient population, trauma patients show higher level detections of bloodborne infectious diseases, such as Hepatitis and Human Immunodeficiency Virus. In comparison to bloodborne pathogens, the prevalence of respiratory infections such as SARS-CoV-2 and how that relates with other variables, such as drug usage and trauma type, is currently unknown in trauma populations. Here, we evaluated SARS-CoV-2 seropositivity and antibody isotype profile in 2,542 trauma patients from six Level-1 trauma centers between April and October of 2020 during the first wave of the COVID-19 pandemic. We found that the seroprevalence in trauma victims 18-44 years old (9.79%, 95% confidence interval/CI: 8.33 11.47) was much higher in comparison to older patients (45-69 years old: 6.03%, 4.59-5.88; 70+ years old: 4.33%, 2.54 – 7.20). Black/African American (9.54%, 7.77 – 11.65) and Hispanic/Latino patients (14.95%, 11.80 – 18.75) also had higher seroprevalence in comparison, respectively, to White (5.72%, 4.62 7.05) and Non-Latino patients (6.55%, 5.57 – 7.69). More than half (55.54%) of those tested for drug toxicology had at least one drug present in their system. Those that tested positive for narcotics or sedatives had a significant negative correlation with seropositivity, while those on anti-depressants trended positive. These findings represent an important consideration for both the patients and first responders that treat trauma patients facing potential risk of respiratory infectious diseases like SARS-CoV-2