Single-cell RNA sequencing (scRNA-seq) is a technique that has proven to be a powerful tool for a wide range of fields and research studies. However, scRNA-seq data analysis has been dominated by scientists highly trained in bioinformatics or those with extensive computational experience and understanding. Recently, this trend has begun to shift as more user-friendly web-based scRNA-seq analysis tools have been developed that require little computational experience to use.
View Article and Find Full Text PDFBackground: Current cancer immunotherapies have made tremendous impacts but generally lack high response rates, especially in ovarian cancer. New therapies are needed to provide increased benefits. One understudied approach is to target the large population of immunosuppressive tumor-associated macrophages (TAMs).
View Article and Find Full Text PDFAlthough obesity can promote cancer, it may also increase immunotherapy efficacy in what has been termed the obesity-immunotherapy paradox. Mechanisms of this effect are unclear, although obesity alters key inflammatory cytokines and can promote an inflammatory state that may modify tumor-infiltrating lymphocytes and tumor-associated macrophage populations. To identify mechanisms by which obesity affects antitumor immunity, we examined changes in cell populations and the role of the proinflammatory adipokine leptin in immunotherapy.
View Article and Find Full Text PDFIntroduction: Bacterial sepsis is a life-threatening disease and a significant clinical problem caused by host responses to a microbial infection. Sepsis is a leading cause of death worldwide and, importantly, a significant cause of morbidity and mortality in combat settings, placing a considerable burden on military personnel and military health budgets. The current method of treating sepsis is restricted to pathogen identification, which can be prolonged, and antibiotic administration, which is, initially, often suboptimal.
View Article and Find Full Text PDFThis work establishes that Kupffer cell release of platelet activating factor (PAF), a lipidic molecule with pro-inflammatory and vasoactive signaling properties, dictates dose-limiting siRNA nanocarrier-associated toxicities. High-dose intravenous injection of siRNA-polymer nano-polyplexes (si-NPs) elicited acute, shock-like symptoms in mice, associated with increased plasma PAF and consequently reduced PAF acetylhydrolase (PAF-AH) activity. These symptoms were completely prevented by prophylactic PAF receptor inhibition or Kupffer cell depletion.
View Article and Find Full Text PDFSurface enhanced Raman spectroscopy enables robust, rapid analysis on highly dilute samples. To be useful, the technique needs sensing substrates that will enhance intrinsically weak Raman signals of trace analytes. In particular, three-dimensional substrates such as zinc oxide nanowires decorated with electron-beam deposited silver nanoparticles are easily fabricated and serve the dual need of structural stability and detection sensitivity.
View Article and Find Full Text PDFBackground: New treatment options for ovarian cancer are urgently required. Tumor-associated macrophages (TAMs) are an attractive target for therapy; repolarizing TAMs from M2 (pro-tumor) to M1 (anti-tumor) phenotypes represents an important therapeutic goal. We have previously shown that upregulated NF-kappaB (NF-κB) signaling in macrophages promotes M1 polarization, but effects in the context of ovarian cancer are unknown.
View Article and Find Full Text PDFBackground: Helper T cell activity is dysregulated in a number of diseases including those associated with rheumatic autoimmunity. Treatment options are limited and usually consist of systemic immune suppression, resulting in undesirable consequences from compromised immunity. Hedgehog (Hh) signaling has been implicated in the activation of T cells and the formation of the immune synapse, but remains understudied in the context of autoimmunity.
View Article and Find Full Text PDF"Smart", dual pH-responsive, and endosomolytic polymeric nanoparticles have demonstrated great potential for localized drug delivery, especially for siRNA delivery to the cytoplasm of cells. However, targeted delivery to a specific cell phenotype requires an additional level of functionality. Copper-catalyzed azide-alkyne cycloaddition (CuAAC) is a highly selective bioconjugation reaction that can be performed in conjunction with other polymerization techniques without adversely affecting reaction kinetics, but there exists some concern for residual copper causing cytotoxicity.
View Article and Find Full Text PDFExpression of olfactory receptors (ORs) has been reported in many human tissues outside the nasal epithelium. ORs have been validated as biomarkers in prostate cancer. In breast cancer, however, the expression and role of OR genes remain understudied.
View Article and Find Full Text PDFWhile polymeric nano-formulations for RNAi therapeutics hold great promise for molecularly-targeted, personalized medicine, they possess significant systemic delivery challenges including rapid clearance from circulation and the potential for carrier-associated toxicity due to cationic polymer or lipid components. Herein, we evaluated the in vivo pharmacokinetic and safety impact of often-overlooked formulation parameters, including the ratio of carrier polymer to cargo siRNA and hydrophobic siRNA modification in combination with hydrophobic polymer components (dual hydrophobization). For these studies, we used nano-polyplexes (NPs) with well-shielded, zwitterionic coronas, resulting in various NP formulations of equivalent hydrodynamic size and neutral surface charge regardless of charge ratio.
View Article and Find Full Text PDFAcinetobacter baumannii is a Gram-negative bacterium of increasing concern due to its virulence and persistence in combat and healthcare environments. The incidence of both community-acquired and nosocomial A. baumannii infections is on the rise in foreign and domestic healthcare facilities.
View Article and Find Full Text PDFAlthough siRNA-based nanomedicines hold promise for cancer treatment, conventional siRNA-polymer complex (polyplex) nanocarrier systems have poor pharmacokinetics following intravenous delivery, hindering tumor accumulation. Here, we determined the impact of surface chemistry on the in vivo pharmacokinetics and tumor delivery of siRNA polyplexes. A library of diblock polymers was synthesized, all containing the same pH-responsive, endosomolytic polyplex core-forming block but different corona blocks: 5 kDa (benchmark) and 20 kDa linear polyethylene glycol (PEG), 10 kDa and 20 kDa brush-like poly(oligo ethylene glycol), and 10 kDa and 20 kDa zwitterionic phosphorylcholine-based polymers (PMPC).
View Article and Find Full Text PDFA rationally-designed library of ternary siRNA polyplexes was developed and screened for gene silencing efficacy in vitro and in vivo with the goal of overcoming both cell-level and systemic delivery barriers. [2-(dimethylamino)ethyl methacrylate] (DMAEMA) was homopolymerized or copolymerized (50mol% each) with butyl methacrylate (BMA) from a reversible addition - fragmentation chain transfer (RAFT) chain transfer agent, with and without pre-conjugation to polyethylene glycol (PEG). Both single block polymers were tested as core-forming units, and both PEGylated, diblock polymers were screened as corona-forming units.
View Article and Find Full Text PDFThe rise of multi-drug resistance has decreased the effectiveness of antibiotics, which has led to increased mortality rates associated with symptomatic bacteremia, or bacterial sepsis. To combat decreasing antibiotic effectiveness, extracorporeal bacterial separation approaches have been proposed to capture and separate bacteria from blood. However, bacteremia is dynamic and involves host-pathogen interactions across various anatomical sites.
View Article and Find Full Text PDFBackground: MR-guided focused ultrasound or high-intensity focused ultrasound (MRgFUS/MRgHIFU) is a non-invasive therapeutic modality with many potential applications in areas such as cancer therapy, drug delivery, and blood-brain barrier opening. However, the large financial costs involved in developing preclinical MRgFUS systems represent a barrier to research groups interested in developing new techniques and applications. We aim to mitigate these challenges by detailing a validated, open-source preclinical MRgFUS system capable of delivering thermal and mechanical FUS in a quantifiable and repeatable manner under real-time MRI guidance.
View Article and Find Full Text PDFGold nanoparticles (AuNPs) were functionalized for rapid binding of Acinetobacter baumannii (A. baumannii), a Gram-negative bacterium. AuNPs were functionalized with colistin (Col), a polycationic antibiotic, using a two-step self-assembly process, in which heterobifunctional polyethylene glycol (PEG) was used as a linker.
View Article and Find Full Text PDFTumor-associated macrophages (TAMs) are critically important in the context of solid tumor progression. Counterintuitively, these host immune cells can often support tumor cells along the path from primary tumor to metastatic colonization and growth. Thus, the ability to transform protumor TAMs into antitumor, immune-reactive macrophages would have significant therapeutic potential.
View Article and Find Full Text PDFBiomaterials
August 2016
Formation of stable, long-circulating siRNA polyplexes is a significant challenge in translation of intravenously-delivered, polymeric RNAi cancer therapies. Here, we report that siRNA hydrophobization through conjugation to palmitic acid (siPA) improves stability, in vivo pharmacokinetics, and tumor gene silencing of PEGylated nanopolyplexes (siPA-NPs) with balanced cationic and hydrophobic content in the core relative to the analogous polyplexes formed with unmodified siRNA, si-NPs. Hydrophobized siPA loaded into the NPs at a lower charge ratio (N(+):P(-)) relative to unmodified siRNA, and siPA-NPs had superior resistance to siRNA cargo unpackaging in comparison to si-NPs upon exposure to the competing polyanion heparin and serum.
View Article and Find Full Text PDFPreterm premature rupture of membranes causes 40% of all preterm births, affecting 150000 women each year in the United States. Prenatal diagnostic procedures and surgical interventions increase incidence of adverse events, leading to iatrogenic membrane rupture after a fetoscopic procedure in 45% of cases. We propose an ultrathin, self-adherent, poly-L-lactic acid patch ("nanofilm") as a reparative wound closure after endoscopic/fetoscopic procedures.
View Article and Find Full Text PDFA series of endosomolytic mixed micelles was synthesized from two diblock polymers, poly[ethylene glycol-b-(dimethylaminoethyl methacrylate-co-propylacrylic acid-co-butyl methacrylate)] (PEG-b-pDPB) and poly[dimethylaminoethyl methacrylate-b-(dimethylaminoethyl methacrylate-co-propylacrylic acid-co-butyl methacrylate)] (pD-b-pDPB), and used to determine the impact of both surface PEG density and PEG molecular weight on overcoming both intracellular and systemic siRNA delivery barriers. As expected, the percent PEG composition and PEG molecular weight in the corona had an inverse relationship with mixed micelle zeta potential and rate of cellular internalization. Although mixed micelles were internalized more slowly, they generally produced similar gene silencing bioactivity (∼ 80% or greater) in MDA-MB-231 breast cancer cells as the micelles containing no PEG (100 D/no PEG).
View Article and Find Full Text PDFA dual-targeted siRNA nanocarrier has been synthesized and validated that is selectively activated in environments where there is colocalization of two breast cancer hallmarks, elevated matrix metalloproteinase (MMP) activity and folate receptor overexpression. This siRNA nanocarrier is self-assembled from two polymers containing the same pH-responsive, endosomolytic core-forming block but varying hydrophilic, corona-forming blocks. The corona block of one polymer consists of a 2 kDa PEG attached to a terminal folic acid (FA); the second polymer contains a larger (Y-shaped, 20 kDa) PEG attached to the core block by a proximity-activated targeting (PAT), MMP7-cleavable peptide.
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