Characterizing Lipid-Coated Mesoporous Silica Nanoparticles as CD169-Binding Delivery System for Rilpivirine and Cabotegravir.

Herein, lipid-coated mesoporous silica nanoparticles (LMSN) are investigated as biomimetic delivery vehicle for two antiretroviral compounds (ARVs), rilpivirine (RPV) and cabotegravir (CAB). Monosialodihexosylganglioside (GM3) is incorporated into the membrane to facilitate LMSN binding to CD169 (Siglec-1)-expressing myeloid cells, that are predominantly expressed in secondary lymphoid tissues in vivo. It is demonstrated that in addition to providing CD169-binding functionalities, the lipid membrane around the silica core provides stealth properties that dampen the inflammatory cytokine response to ARVs-loaded LMSN in human monocyte-derived macrophages. Quantification of RPV and CAB releases from nanoparticles, and assessment of antiviral potency to human immunodeficiency virus (HIV-1) infection in vitro reveals that RPV and CAB co-formulated into LMSN retain optimal antiviral potency for 90 days, even upon storage at room temperature, making LMSN an attractive nanoplatform, immune to cold chain requirements. These findings suggest that GM3-LMSN equip the mesoporous silica nanoparticle (MSN) core with lipid-derived properties for surface passivation and lipid-mediated binding that are of high interest for achieving an effective delivery of ARVs to tissue reservoirs of HIV-1 replication.

Comparison of predictive value of risk scores for gastrointestinal bleeding in antiplatelet therapy.

Gastrointestinal bleeding (GIB) is the most common serious bleeding complication of antiplatelet therapy. The bleeding risk score (BRS) of GIB may help to determine the risk of bleeding, and provides a reference for the formulation of antiplatelet therapy regimen in clinical practice, but we found that no specific risk scores are available in East Asian patients. This study analyzed patients who were administered antiplatelet therapy from May 2015 to December 2018 in two medical centers. Patient's baseline data were obtained. We assessed four BRSs (New Score, RIETE Score, Cuschieri Score, de Groot Score) and compared them using the area under the receiver operating characteristic curve (AUC). The 4,052 patients enrolled in this study had an average age of 69.6 ± 10.8 years, and 65.9% of them were male. Among the 4,052 patients included, 171 patients experienced GIB within 6 months of follow-up. In the study population, the AUCs for the New, RIETE, Cuschieri, and de Groot scores were 0.673 (95% confidence interval (CI) 0.616-0.729, P < .001), 0.742 (95% CI 0.690-0.794, P < .001), 0.598 (95% CI 0.537-0.659, P = .002), and 0.875 (95% CI 0.839-0.912, P < .001), respectively. After validation, the de Groot Score has better performance. Among the four scores, the de Groot Score might be more suitable for helping Chinese clinicians to predict the risk of GIB in patients taking antiplatelet drugs, and reduce GIB events.

Power Dissipation of an Inductively Coupled Plasma Torch under E Mode Dominated Regime.

This paper focuses on the power dissipation of a plasma torch used for an optical surface fabrication process. The process utilizes an inductively coupled plasma (ICP) torch that is equipped with a De-Laval nozzle for the delivery of a highly collimated plasma jet. The plasma torch makes use of a self-igniting coil and an intermediate co-axial tube made of alumina. The torch has a distinctive thermal and electrical response compared to regular ICP torches. In this study, the results of the power dissipation investigation reveal the true efficiency of the torch and discern its electrical response. By systematically measuring the coolant parameters (temperature change and flow rate), the power dissipation is extrapolated. The radio frequency power supply is set to 800 W, E mode, throughout the research presented in this study. The analytical results of power dissipation, derived from the experiments, show that 15.4% and 33.3% are dissipated by the nozzle and coil coolant channels, respectively. The experiments also enable the determination of the thermal time constant of the plasma torch for the entire range of RF power.

Comparison of clinical performance of four gastrointestinal bleeding risk scores in Chinese patients with atrial fibrillation receiving oral anticoagulants.

Gastrointestinal bleeding is the most common bleeding complication during anticoagulant therapy. A reliable bleeding risk score can help the clinician assess risk of bleeding in individual patients and select the anticoagulant regimen. This study retrospectively analyzed the data of patients with atrial fibrillation who received anticoagulant therapy from July 2015 to December 2018 at two centers-the Fujian Medical University Union Hospital and Fuzhou Second Hospital Affiliated to Xiamen University. Demographic data, clinical findings, and laboratory results were collected from the hospital records. Patients were followed up for 6 months. The performance of four bleeding risk scores (New Score, RIETE Score, Cuschieri et al. Score, de Groot et al. Score) for prediction of gastrointestinal bleeding was assessed using the area under the curve. A total of 3462 patients (mean age, 66.3 ± 11.5 years; 59.6% males; 1055 direct oral anticoagulants users and 2407 warfarin users) were followed up for 6 months. While 99/3462 (2.9%) patients had gastrointestinal bleeding. The area under the curves for the New, RIETE, Cuschieri et al., de Groot et al. scores were 0.652 (95% CI 0.576-0.728), 0.862 (95% CI 0.809-0.914), 0.606 (95% CI 0.527-0.685), and 0.873 (95% CI 0.816-0.929), respectively. Among the four BRSs evaluated, the RIETE score and the de Groot et al. score appear to have the good predictive value, while the NEW score and the Cuschieri et al. score did not sufficiently predict gastrointestinal bleeding risk within the study Chinese population.

A New Score for Predicting Acute Gastrointestinal Bleeding in Patients Administered Oral Antiplatelet Drugs.

Antiplatelet drugs may increase the risk of gastrointestinal bleeding. Currently, there is no specific score for predicting the risk of gastrointestinal bleeding caused by oral antiplatelet drugs. In this study, the gastrointestinal bleeding risk score was established and compared with the CRUSADE score in order to reduce the occurrence of clinical gastrointestinal bleeding events. Our study included 4052 patients who received oral antiplatelet drugs. Data were obtained from the patient medical records inpatient system. Cases of acute gastrointestinal bleeding and mortality were recorded. The bleeding score was established by logistic regression, area under the receiver operating characteristic curve, and the Hosmer-Lemeshow test. Finally, 171 patients had acute gastrointestinal bleeding. The mortality rates of patients in the bleeding and nonbleeding groups were 24.6 and 4.7%, respectively. A multivariate analysis revealed that an age of >65 years, anemia, recent major bleeding, a history of gastrointestinal bleeding, combined oral anticoagulants, and dual antiplatelet therapy are risk factors, and combined proton pump inhibitors are protective factors for acute gastrointestinal bleeding. We used these risk factors to establish a score for predicting acute gastrointestinal bleeding, named (ABC)2D score. The area under the curve for (ABC)2D score was 0.857 (p < 0.001), higher than the CRUSADE score of 0.693 (p < 0.001). The Hosmer-Lemeshow p value was 0.324. We developed the (ABC)2D score based on seven risk factors (i.e., age, anemia, recent major bleeding, a history of gastrointestinal bleeding, no-proton pump inhibitors use, combined oral anticoagulants, and dual antiplatelet therapy). (ABC)2D score was superior to the CRUSADE score. This new risk-scoring model may help to identify patients at a significant risk of gastrointestinal bleeding.

Membrane-wrapped nanoparticles probe divergent roles of GM3 and phosphatidylserine in lipid-mediated viral entry pathways.

Gold nanoparticles (NPs) wrapped in a membrane can be utilized as artificial virus nanoparticles (AVNs) that combine the large nonblinking or bleaching optical cross-section of the NP core with the biological surface properties and functionalities provided by a self-assembled lipid membrane. We used these hybrid nanomaterials to test the roles of monosialodihexosylganglioside (GM3) and phosphatidylserine (PS) for a lipid-mediated targeting of virus-containing compartments (VCCs) in macrophages. GM3-presenting AVNs bind to CD169 (Siglec-1)-expressing macrophages, but inclusion of PS in the GM3-containing AVN membrane decreases binding. Molecular dynamics simulations of the AVN membrane and experimental binding studies of CD169 to GM3-presenting AVNs reveal Na+-mediated interactions between GM3 and PS as a potential cause of the antagonistic action on binding by the two negatively charged lipids. GM3-functionalized AVNs with no or low PS content localize to tetherin+, CD9+ VCC in a membrane composition-depending fashion, but increasing amounts of PS in the AVN membrane redirect the NP to lysosomal compartments. Interestingly, this compartmentalization is highly GM3 specific. Even AVNs presenting the related monosialotetrahexosylganglioside (GM1) fail to achieve an accumulation in VCC. AVN localization to VCC was observed for AVN with gold NP core but not for liposomes, suggesting that NP sequestration into VCC has additional requirements beyond ligand (GM3)-receptor (CD169) recognition that are related to the physical properties of the NP core. Our results confirm AVN as a scalable platform for elucidating the mechanisms of lipid-mediated viral entry pathways and for selective intracellular targeting.

Nanoparticle-cell interactions induced apoptosis: a case study with nanoconjugated epidermal growth factor.

In addition to the intrinsic toxicity associated with the chemical composition of nanoparticles (NP) and their ligands, biofunctionalized NP can perturb specific cellular processes through NP-cell interactions and induce programmed cell death (apoptosis). In the case of the epidermal growth factor (EGF), nanoconjugation has been shown to enhance the apoptotic efficacy of the ligand, but the critical aspects of the underlying mechanism and its dependence on the NP morphology remain unclear. In this manuscript we characterize the apoptotic efficacy of nanoconjugated EGF as a function of NP size (with sphere diameters in the range 20-80 nm), aspect ratio (A.R., in the range of 4.5 to 8.6), and EGF surface loading in EGFR overexpressing MDA-MB-468 cells. We demonstrate a significant size and morphology dependence in this relatively narrow parameter space with spherical NP with a diameter of approx. 80 nm being much more efficient in inducing apoptosis than smaller spherical NP or rod-shaped NP with comparable EGF loading. The nanoconjugated EGF is found to trigger an EGFR-dependent increase in cytoplasmic reactive oxygen species (ROS) levels but no indications of increased mitochondrial ROS levels or mitochondrial membrane damage are detected at early time points of the apoptosis induction. The increase in cytoplasmic ROS is accompanied by a perturbation of the intracellular glutathione homeostasis, which represents an important check-point for NP-EGF mediated apoptosis. Abrogation of the oxidative stress through the inhibition of EGFR signaling by the EGFR inhibitor AG1478 or addition of antioxidants N-acetyl cysteine (NAC) or tempol, but not trolox, successfully suppressed the apoptotic effect of nanoconjugated EGF. A model to account for the observed morphology dependence of EGF nanoconjugation enhanced apoptosis and the underlying NP-cell interactions is discussed.

Lipid-Mediated Targeting with Membrane-Wrapped Nanoparticles in the Presence of Corona Formation.

Membrane-wrapped nanoparticles represent a versatile platform for utilizing specific lipid-receptor interactions, such as siallyllactose-mediated binding of the ganglioside GM3 to Siglec1 (CD169), for targeting purposes. The membrane wrap around the nanoparticles not only serves as a matrix to incorporate GM3 as targeting moiety for antigen-presenting cells but also offers unique opportunities for constructing a biomimetic surface from lipids with potentially protein-repellent properties. We characterize nonspecific protein adsorption (corona formation) to membrane-wrapped nanoparticles with core diameters of approximately 35 and 80 nm and its effect on the GM3-mediated targeting efficacy as a function of surface charge through combined in vitro and in vivo studies. The stability and fate of the membrane wrap around the nanoparticles in a simulated biological fluid and after uptake in CD169-expressing antigen-presenting cells is experimentally tested. Finally, we demonstrate in hock immunization studies in mice that GM3-decorated membrane-wrapped nanoparticles achieve a selective enrichment in the peripheral regions of popliteal lymph nodes that contain high concentrations of CD169-expressing antigen-presenting cells.

Dressing up Nanoparticles: A Membrane Wrap to Induce Formation of the Virological Synapse.

Next-generation nanoparticle-based drug delivery systems require the ability to target specific organelles or subcellular regions in selected target cells. Human immunodeficiency virus type I (HIV-1) particles are evolutionarily optimized nanocarriers that have evolved to avoid intracellular degradation and achieve enrichment at the synapse between mature dendritic cells (mDCs) and T cells by subverting cellular trafficking mechanisms. This study demonstrates that integration of the glycosphingolipid, GM3, in a membrane around a solid nanoparticle (NP) core is sufficient to recapitulate key aspects of the virus particle trafficking in mDCs. GM3-presenting artificial virus NPs (GM3-AVNs) accumulate in CD169(+) and CD81(+) nonlysosomal compartments in an actin-dependent process that mimics the sequestration of HIV-1. Live-cell optical tracking studies reveal a preferential recruitment and arrest of surface scanning CD4(+) T cells in direct vicinity to the AVN-enriched compartments. The formed mDC-T cell conjugates exhibit strong morphological similarities between the GM3-AVN-containing mDC-T cell synapse and the HIV-1 virological synapse, indicating that GM3-CD169 interactions alone are sufficient for establishing the mDC-T cell virological synapse. These results emphasize the potential of the GM3-AVN approach for providing therapeutic access to a key step of the host immune response--formation of the synaptic junction between an antigen-presenting cell (mDC) and T cells--for modulating and controlling immune responses.

Glycosphingolipid-functionalized nanoparticles recapitulate CD169-dependent HIV-1 uptake and trafficking in dendritic cells.

Ganglioside GM3, a host-derived glycosphingolipid incorporated in the membrane of human immunodeficiency virus-1 (HIV-1) viral particles, mediates interactions between HIV-1 and Siglec1/CD169, a protein expressed on dendritic cells (DCs). Such interactions, which seem to be independent of viral envelope glycoprotein gp120, are poorly understood. Here we develop a model system consisting of self-assembled artificial virus nanoparticles (AVNs) that are free of viral glycoproteins or other host-derived glycolipids and glycoproteins. These plasmonic AVNs contain a membrane of defined composition wrapped around a solid metal core. GM3-containing AVNs are captured by CD169-expressing HeLa cells or mature DCs, and are sequestered within non-lysosomal tetraspanin-positive compartments. This distribution is reminiscent of CD169-dependent HIV-1 sequestration in mature DCs. Our results highlight GM3-CD169 binding as a gp120-independent signal for sequestration and preservation of HIV-1 infectivity. They also indicate that plasmonic AVNs offer improved features over liposome-based systems and represent a versatile tool for probing specific virus-cell interactions.