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Background Higher blunt cerebrovascular injury (BCVI) grade and lack of medical therapy are associated with stroke. Knowledge of stroke risk factors specific to individual grades may help tailor BCVI therapy to specific injury characteristics.Methods A post-hoc analysis of a 16 center, prospective, observational trial (2018-2020) was performed including grade 1 internal carotid artery (ICA) BCVI. Repeat imaging was considered the second imaging occurrence only.Results From 145 grade 1 ICA BCVI included, 8 (5.5%) suffered a stroke. Grade 1 ICA BCVI with stroke were more commonly treated with mixed anticoagulation and antiplatelet therapy (75.0% vs 9.6%, P <.001) and less commonly antiplatelet therapy (25.0% vs 82.5%, P = .001) compared to injuries without stroke. Of the 8 grade 1 ICA BCVI with stroke, 4 (50.0%) had stroke after medical therapy was started. In comparing injuries with resolution at repeat imaging to those without, stroke occurred in 7 (15.9%) injuries without resolution and 0 (0%) injuries with resolution (P = .005). At repeat imaging in grade 1 ICA BCVI with stroke, grade of injury was grade 1 in 2 injuries, grade 2 in 3 injuries, grade 3 in 1 injury, and grade 5 in one injury.Discussion While the stroke rate for grade 1 ICA BCVI is low overall, injury persistence appears to heighten stroke risk. Some strokes occurred despite initiation of medical therapy. Repeat imaging is needed in grade 1 ICA BCVI to evaluate for injury progression or resolution.

Despite intense scrutiny throughout the pandemic, development of efficacious drugs against SARS-CoV-2 spread remains hindered. Understanding the underlying mechanisms of viral infection is fundamental for developing novel treatments. While angiotensin converting enzyme 2 (ACE2) is accepted as the key entry receptor of the virus, other infection mechanisms exist. Dendritic cell-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN) and its counterpart DC-SIGN-related (DC-SIGNR, also known as L-SIGN) have been recognized as possessing functional roles in COVID-19 disease and binding to SARS-CoV-2 has been demonstrated previously with ensemble and qualitative techniques. Here we examine the thermodynamic and kinetic parameters of the ligand–receptor interaction between these C-type lectins and the SARS-CoV-2 S1 protein using force–distance curve-based AFM and biolayer interferometry. We evidence that the S1 receptor binding domain is likely involved in this bond formation. Further, we employed deglycosidases and examined a nonglycosylated S1 variant to confirm the significance of glycosylation in this interaction. We demonstrate that the high affinity interactions observed occur through a mechanism distinct from that of ACE2.

Polymer–drug conjugates are widely investigated to enhance the selectivity of therapeutic drugs to cancer cells, as well as increase circulation lifetime and solubility of poorly soluble drugs. In order to direct these structures selectively to cancer cells, targeting agents are often conjugated to the nanoparticle surface as a strategy to limit drug accumulation in non-cancerous cells and therefore reduce systemic toxicity. Here, we report a simple procedure to generate biodegradable polycarbonate graft copolymer nanoparticles that allows for highly efficient conjugation and intracellular release of S-(+)-camptothecin, a topoisomerase I inhibitor widely used in cancer therapy. The drug–polymer conjugate showed strong efficacy in inhibiting cell proliferation across a range of cancer cell lines over non-cancerous phenotypes, as a consequence of the increased intracellular accumulation and subsequent drug release specifically in cancer cells. The enhanced drug delivery towards cancer cells in vitrodemonstrates the potential of this platform for selective treatments without the addition of targeting ligands.

Background Use of endovascular intervention (EI) for blunt cerebrovascular injury (BCVI) is without consensus guidelines. Rates of EI use and radiographic characteristics of BCVI undergoing EI nationally are unknown.Methods A post-hoc analysis of a prospective, observational study at 16 U.S. trauma centers from 2018 to 2020 was conducted. Internal carotid artery (ICA) BCVI was included. The primary outcome was EI use. Multivariable logistic regression was performed for predictors of EI use.Results From 332 ICA BCVI included, 21 (6.3%) underwent EI. 0/145 (0%) grade 1, 8/101 (7.9%) grade 2, 12/51 (23.5%) grade 3, and 1/20 (5.0%) grade 4 ICA BCVI underwent EI. Stroke occurred in 6/21 (28.6%) ICA BCVI undergoing EI and in 33/311 (10.6%) not undergoing EI (P= .03), with all strokes with EI use occurring prior to or at the same time as EI. Percentage of luminal stenosis (37.75 vs 20.29%, P= .01) and median pseudoaneurysm size (9.00 mm vs 3.00 mm, P= .01) were greater in ICA BCVI undergoing EI. On logistic regression, only pseudoaneurysm size was associated with EI (odds ratio 1.205, 95% CI 1.035-1.404, P= .02). Of the 8 grade 2 ICA BCVI undergoing EI, 3/8 were grade 2 and 5/8 were grade 3 prior to EI. Of the 12 grade 3 ICA BCVI undergoing EI, 11/12 were grade 3 and 1/12 was a grade 2 ICA BCVI prior to EI.Discussion Pseudoaneurysm size is associated with use of EI for ICA BCVI. Stroke is more common in ICA BCVI with EI but did not occur after EI use.

Theranostics is a strategy that combines multiple functions such as targeting, stimulus-responsive drug release, and diagnostic imaging into a single platform, often with the aim of developing personalized medicine.1,2 Based on this concept, several well-established hyperbranched polymeric theranostic nanoparticles were synthesized and characterized as model nanomedicines to investigate how their properties affect the distribution of loaded drugs at both the cell and whole animal levels. An 8-mer peptide aptamer was covalently bound to the periphery of the nanoparticles to achieve both targeting and potential chemosensitization functionality against heat shock protein 70 (Hsp70). Doxorubicin was also bound to the polymeric carrier as a model chemotherapeutic drug through a degradable hydrazone bond, enabling pH-controlled release under the mildly acid conditions that are found in the intracellular compartments of tumor cells. In order to track the nanoparticles, cyanine-5 (Cy5) was incorporated into the polymer as an optical imaging agent. In vitrocellular uptake was assessed for the hyperbranched polymer containing both doxorubicin (DOX) and Hsp70 targeted peptide aptamer in live MDA-MB-468 cells, and was found to be greater than that of either the untargeted, DOX-loaded polymer or polymer alone due to the specific affinity of the peptide aptamer for the breast cancer cells. This was also validated in vivowith the targeted polymers showing much higher accumulation within the tumor 48 h postinjection than the untargeted analogue. More detailed assessment of the nanomedicine distribution was achieved by directly following the polymeric carrier and the doxorubicin at both the in vitrocellular level via compartmental analysis of confocal images of live cells and in whole tumors ex vivousing confocal imaging to visualize the distribution of the drug in tumor tissue as a function of distance from blood vessels. Our results indicate that this polymeric carrier shows promise as a cancer theranostic, demonstrating active targeting to tumor cells with the capability for simultaneous drug release.

ABSTRACTProdrugs reliant on microbial activation are widely used but exhibit a range of efficacies that remain poorly understood. The anti-inflammatory compound 5-aminosalicylic acid (5-ASA), which is packaged in a variety of azo-linked prodrugs provided to most Ulcerative Colitis (UC) patients, shows confounding inter-individual variabilities in response. Such prodrugs must be activated by azo-bond reduction to form 5-ASA, a process that has been attributed to both enzymatic and non-enzymatic catalysis. Gut microbial azoreductases (AzoRs) are the first catalysts shown to activate azo-linked drugs and to metabolize toxic azo-chemicals. Here, we chart the scope of the structural and functional diversity of AzoRs in health and in patients with the inflammatory bowel diseases (IBDs) UC and Crohn’s Disease (CD). Using structural metagenomics, we define the landscape of gut microbial AzoRs in 413 healthy donor and 1059 IBD patient fecal samples. Firmicutes encode a significantly higher number of unique AzoRs compared to other phyla. However, structural and biochemical analyses of distinct AzoRs from the human microbiome reveal significant differences between prevalent orthologs in the processing of toxic azo-dyes, and their generally poor activation of IBD prodrugs. Furthermore, while individuals with IBD show higher abundances of AzoR-encoding gut microbial taxa than healthy controls, the overall abundance of AzoR-encoding microbes is markedly low in both disease and health. Together, these results establish that gut microbial AzoRs are functionally diverse but sparse in both health and disease, factors that may contribute to non-optimal processing of azo-linked prodrugs and idiopathic IBD drug responses.

As polymeric nanomedicines grow increasingly complex in design, an effective therapeutic release is often inherently tied to localisation to specific intracellular compartments or microenvironments. The inclusion of environmentally-sensitive moieties links the functionality of such materials to the trafficking behaviours exhibited once materials have obtained access to the cellular milieu. In order to perform their designed function, such materials often need to encounter specific biological cues or stimuli. As such, there is an increased need to improve our understanding of how the physicochemical properties of nanomaterials influence post-internalisation behaviours. Amongst the unknown factors that may contribute to the trafficking behaviours and distribution of polymers within the cellular environment, is the influence of the components selected in the development of such materials. To examine whether composition and arrangement of components within small polymeric nanomaterials contribute to their ability to navigate the intracellular space, here we utilise fluorophores to model component selection, varying the fluorescent handle selected and its method of incorporation. We explore the intracellular behaviours of well-characterised hyperbranched polymers in live MDA-MB-468 breast cancer cells in vitro. Changes in distribution as a function of both fluorophore selection and placement are reported, and our data suggest that the individual components used to produce potential nanomedicines are critical to their overall functioning and efficacy. Further to this, through the use of a novel non-conjugated targeting ligand, we demonstrate that there is inherent competition between component-directing factors and cellular influences on the ultimate fate of the polymers. The behaviours reported here suggest that not only does component selection contribute to intracellular processing, but these factors could potentially be harnessed when designing polymers to ensure improved functionality of future materials for therapeutic delivery.

Nanoscaled polymeric materials are increasingly being investigated as pharmaceutical products, drug/gene delivery vectors, or health-monitoring devices. Surface charge is one of the dominant parameters that regulates nanomaterial behavior in vivo. In this paper, we demonstrated how control over chemical synthesis allowed manipulation of nanoparticle surface charge, which in turn greatly influenced the in vivobehavior. Three methacrylate/methacrylamide-based monomers were used to synthesize well-defined hyperbranched polymers (HBP) by reversible addition–fragmentation chain transfer (RAFT) polymerization. Each HBP had a hydrodynamic diameter of approximately 5 nm as determined by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Incorporation of a fluorescent moiety within the polymeric nanoparticles allowed determination of how charge affected the in vivopharmacokinetic behavior of the nanomaterials and the biological response to them. A direct correlation between surface charge, cellular uptake, and cytotoxicity was observed, with cationic HBPs exhibiting higher cellular uptake and cytotoxicity than their neutral and anionic counterparts. Evaluation of the distribution of the differently charged HBPs within macrophages showed that all HBPs accumulated in the cytoplasm, but cationic HBPs also trafficked to, and accumulated within, the nucleus. Although cationic HBPs caused slight hemolysis, this was generally below accepted levels for in vivosafety. Analysis of pharmacokinetic behavior showed that cationic and anionic HBPs had short blood half-lives of 1.82 ± 0.51 and 2.34 ± 0.93 h respectively, compared with 5.99 ± 2.30 h for neutral HBPs. This was attributed to the fact that positively charged surfaces are more readily covered with opsonin proteins and thus more visible to phagocytic cells. This was supported by in vitroflow cytometric and qualitative live cell imaging studies, which showed that cationic HBPs tended to be taken up by macrophages more effectively and rapidly than neutral and anionic particles.

ABSTRACTMycophenolate mofetil (MMF) is an important immunosuppressant prodrug prescribed to prevent organ transplant rejection and to treat autoimmune diseases. MMF usage, however, is limited by severe gastrointestinal toxicity that is observed in approximately 45% of MMF recipients. The active form of the drug, mycophenolic acid (MPA), undergoes extensive enterohepatic recirculation by bacterial β-glucuronidase (GUS) enzymes, which reactivate MPA from mycophenolate glucuronide (MPAG) within the gastrointestinal tract. GUS enzymes demonstrate distinct substrate preferences based on their structural features, and gut microbial GUS enzymes that reactivate MPA have not been identified. Here, we compare the fecal microbiomes of transplant recipients receiving MMF to healthy individuals using shotgun metagenomic sequencing. We find that neither microbial composition nor the presence of specific structural classes of GUS genes are sufficient to explain the differences in MPA reactivation measured between fecal samples from the two cohorts. We next employed a GUS-specific activity-based chemical probe and targeted metaproteomics to identify and quantify the GUS proteins present in the human fecal samples. The identification of specific GUS enzymes was improved by using the metagenomics data collected from the fecal samples. We found that the presence of GUS enzymes that bind the flavin mononucleotide (FMN) is significantly correlated with efficient MPA reactivation. Furthermore, structural analysis identified motifs unique to these FMN-binding GUS enzymes that provide molecular support for their ability to process this drug glucuronide. These results indicate that FMN-binding GUS enzymes may be responsible for reactivation of MPA and could be a driving force behind MPA-induced GI toxicity.