Amino Acid-Based Polymer-Coated Silver Nanoparticles as Insulin Fibril Inhibitors

To explore the impact of polymer-coated silver nanoparticles (PC-AgNPs) on the extent of the insulin aggregation process, herein, we have synthesized three copolymers comprising poly(ethylene glycol) methyl ether methacrylate (PEGMA) and tert-butoxycarbonyl (Boc)-protected amino acid (alanine, leucine, and phenylalanine) containing methacrylate monomers, via reversible addition-fragmentation chain transfer (RAFT) polymerization. After deprotection of the Boc groups, the as-prepared water-soluble copolymers were coated on silver nanoparticles (Ag NPs), and the role of these NPs on insulin aggregation pathways was examined by multifarious spectroscopic and microscopic techniques. The extent of the inhibitory effect against the insulin fibrillation process was found to be related to the surface properties of the NPs, with the highest inhibitory effect detected for phenylalanine-based polymer-coated Ag NPs (PPhe-AgNPs). Using circular dichroism (CD) spectroscopy and Nile red (NR) fluorescence spectroscopy, we investigated the conformational changes and examined the role of hydrophobic interaction in inhibiting the aggregation properties of insulin upon treatment with PC-AgNPs. Furthermore, PC-AgNPs were also able to disintegrate the matured insulin fibrils and efficiently decreased the fibril-induced cytotoxicity, as confirmed by transmission electron microscopy (TEM) and the hemolysis study, respectively. Together, our findings established the novel amino acid-based PC-AgNPs as potent nanomaterials with 77–96% insulin fibril inhibition and marked disaggregation of matured insulin fibrils

Modulating Insulin Aggregation with Charge Variable Cholic Acid-Derived Polymers

To understand the effect of cholic acid (CA)-based charge variable polymeric architectures on modulating the insulin aggregation process, herein, we have designed side-chain cholate-containing charge variable polymers. Three different types of copolymers from 2-(methacryloyloxy)­ethyl cholate with anionic or cationic or neutral units have been synthesized by reversible addition-fragmentation chain transfer polymerization. The effects of these copolymers on the insulin fibrillation process was studied by multiple biophysical approaches including different types of spectroscopic and microscopic analyses. Interestingly, the CA-based cationic polymer (CP-10) was observed to inhibit the insulin fibrillation process in a dose-dependent manner and to act as an effective anti-amyloidogenic agent. Corresponding anionic (AP-10) and neutral (NP-10) copolymers with cholate pendants remained insignificant in controlling the aggregation process. Tyrosine fluorescence assays and Nile red fluorescence measurements demonstrate the role of hydrophobic interaction to explain the inhibitory potencies of CP-10. Furthermore, circular dichroism spectroscopic measurements were carried out to explore the secondary structural changes of insulin fibrils in the presence of cationic polymers with and without cholate moieties. Isothermal titration calorimetry measurements revealed the involvement of electrostatic polar interaction between the CA-based cationic polymer and insulin at different stages of fibrillation. Overall, this work demonstrates the efficacy of the CA-based cationic polymer in controlling the insulin aggregation process and provides a novel dimension to the studies on protein aggregation

DataSheet_1_Prevalence of mpox viral DNA in cutaneous specimens of monkeypox-infected patients: a systematic review and meta-analysis.docx

BackgroundHuman monkeypox (mpox) disease is a multicountry outbreak driven by human–human transmission which has resulted in an international public health emergency. However, there is limited evidence on the positivity rate of skin lesions for mpox viral DNA. We aim to fill this gap by estimating the pooled positivity rate of skin samples with mpox viral DNA from mpox patients globally.MethodsIn this systematic review and meta-analysis, seven databases and several preprint servers have been extensively searched until 17 January 2023 according to a prospectively registered protocol (PROSPERO: CRD42023392505). Articles including the positivity rate of skin samples with mpox viral DNA in mpox-confirmed patients were considered eligible. After a quality assessment, a random-effect meta-analysis was used for pooled prevalence. To explore and resolve heterogeneity, we used statistical methods for outlier detection, influence analysis, and sensitivity analysis.FindingsAmong the 331 articles retrieved after deduplication, 14 studies were finally included. The pooled positivity rate of the skin samples was 98.77% (95% CI: 94.74%–99.72%). After the removal of an influential outlier, I2 for heterogeneity dropped from 92.5% to 10.8%. Meta-regression did not reveal any significant moderator.Conclusion/interpretationThe present findings reinforce that skin lesions act as a reservoir of mpox viral DNA and contribute to a high infectivity risk. This may be a prevailing basis of prompt transmission during the current multicountry outbreak and also needs further investigation. The present imperative outcome may benefit in producing valuable preventive and management procedures in an appropriate health strategy.</p

Difference in QFT results (test–re-test) versus the average of QFT test and re-test results (all on the log scale).

<p>Separate plotting characters are used for each individual and the mean log-difference is shown as the broken horizontal line. We note that there tend to be more points above zero and hence the average difference (test–re-test) lies above 0, indicating higher IFN-γ results upon re-testing of the same specimens. QFT: QuantiFERON-TB Gold In Tube®; IFN-γ: interferon-gamma.</p

Within-person variability in serially repeated (re-test) QFT results (14 individuals tested 4 times on day 0, 3, 9 and 12)

<p>QFT: QuantiFERON-TB Gold In Tube®; IFN-γ: interferon-gamma</p>*<p>The cut-off value for a positive QFT test was IFN-γ≥0.35 IU/mL</p

Test versus re-test QFT results expressed as IFN-γ (IU/mL).

<p>Data for each individual is plotted with different symbols, and the line of equality is shown as the diagonal. Note that more points fall above the line of equality than below, indicating higher IFN-γ levels upon re-testing of blood. The spread of the IFN-γ results from the line of equality increases with increasing IFN-γ results, indicating that a log-transformation was appropriate. QFT: QuantiFERON-TB Gold In Tube®; IFN-γ: interferon-gamma.</p

Raw data for the two individuals with discordant QFT results; both individuals had discordant between-test results and discordant within-person results^*

*<p>Complete QFT results for both individuals are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001850#pone-0001850-t001" target="_blank">Tables 1</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001850#pone-0001850-t002" target="_blank">2</a></p><p>QFT: QuantiFERON-TB Gold In Tube®; IFN-γ: interferon-gamma</p

Test-retest concordance of two QFT tests performed on the same set of specimens (N = 56 paired specimens from 14 subjects)

<p>Concordance = 96.4%; κ = 0.94</p>*<p>The cut-off value for a positive QFT test was IFN-γ≥0.35 IU/mL</p><p>QFT: QuantiFERON-TB Gold In Tube®; IFN-γ: interferon-gamma.</p

Within person variability of log IFN-γ responses over 4 time points (day 0, 3, 9 and 12).

<p>Separate plotting characters are used for each individual (N = 14) who underwent 4 QFT assays on days 0, 3, 9, and 12; the dashed red line indicates the cut-off for QFT test positivity. For each individual, the IFN-γ results taken on four days are plotted on the log scale. Most individuals do not cross the positive test result threshold. For two individuals (lines shown in bold) whose trajectories do cross the threshold, test results are discordant. QFT: QuantiFERON-TB Gold In Tube®; IFN-γ: interferon-gamma.</p

Within-person variability in initial QFT results (14 individuals tested 4 times on day 0, 3, 9 and 12)

<p>QFT: QuantiFERON-TB Gold In Tube®; IFN-γ: interferon-gamma</p>*<p>The cut-off value for a positive QFT test was IFN-γ≥0.35 IU/mL</p