338 research outputs found

    Mass Production and Size Control of Lipid–Polymer Hybrid Nanoparticles through Controlled Microvortices

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    Lipid–polymer hybrid (LPH) nanoparticles can deliver a wide range of therapeutic compounds in a controlled manner. LPH nanoparticle syntheses using microfluidics improve the mixing process but are restricted by a low throughput. In this study, we present a pattern-tunable microvortex platform that allows mass production and size control of LPH nanoparticles with superior reproducibility and homogeneity. We demonstrate that by varying flow rates (i.e., Reynolds number (30–150)) we can control the nanoparticle size (30–170 nm) with high productivity (~3 g/hour) and low polydispersity (~0.1). Our approach may contribute to efficient development and optimization of a wide range of multicomponent nanoparticles for medical imaging and drug delivery.National Heart, Lung, and Blood Institute (Program of Excellence in Nanotechnology (PEN) Award Contract HHSN268201000045C)National Cancer Institute (U.S.) (Grant P01 CA151884)Prostate Cancer Foundation (Award in Nanotherapeutics

    Engineering of lipid-coated PLGA nanoparticles with a tunable payload of diagnostically active nanocrystals for medical imaging

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    Polylactic-co-glycolic acid (PLGA) based nanoparticles are biocompatible and biodegradable and therefore have been extensively investigated as therapeutic carriers. Here, we engineered diagnostically active PLGA nanoparticles that incorporate high payloads of nanocrystals into their core for tunable bioimaging features. We accomplished this through esterification reactions of PLGA to generate polymers modified with nanocrystals. The PLGA nanoparticles formed from modified PLGA polymers that were functionalized with either gold nanocrystals or quantum dots exhibited favorable features for computed tomography and optical imaging, respectively.National Heart, Lung, and Blood Institute (Programs of Excellence in Nanotechnology (PEN) Award, Contract #HHSN268201000045C))National Institutes of Health (U.S.) (R01 EB009638)National Institutes of Health (U.S.) (R01 CA155432)National Institutes of Health (U.S.) (K99 EB012165)Netherlands Organization for Scientific Research ((NWO) ECHO.06.B.047

    An 89Zr-HDL PET Tracer Monitors Response to a CSF1R Inhibitor

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    The immune function within the tumor microenvironment has become a prominent therapeutic target, with tumor-associated macrophages (TAMs) playing a critical role in immune suppression. We propose an 89Zr-labeled high-density lipoprotein (89Zr-HDL) nanotracer as a means of monitoring response to immunotherapy. Methods: Female MMTV-PyMT mice were treated with pexidartinib, a colony-stimulating factor 1 receptor (CSF1R) inhibitor, to reduce TAM density. The accumulation of 89Zr-HDL within the tumor was assessed using PET/CT imaging and autoradiography, whereas TAM burden was determined using immunofluorescence. Results: A significant reduction in 89Zr-HDL accumulation was observed in PET/CT images, with 2.9% ± 0.3% and 3.7% ± 0.2% injected dose/g for the pexidartinib- and vehicle-treated mice, respectively. This reduction was corroborated ex vivo and correlated with decreased TAM density. Conclusion: These results support the potential use of 89Zr-HDL nanoparticles as a PET tracer to quickly monitor the response to CSF1R inhibitors and other therapeutic strategies targeting TAMs.We thank the Small Animal Imaging Core, the Radiochemistry and Molecular Imaging Probes Core, and the Molecular Cytology Core at Memorial Sloan Kettering Cancer Center. This work was supported by National Institutes of Health grants R01 CA204441, P30 CA008748 and R01 CA220234. The authors thank the Tow Foundation and Memorial Sloan Kettering Cancer Center's Center for Molecular Imaging & Nanotechnology (CMINT), the Imaging and Radiation Sciences Program and the MSK Molecularly Targeted Intraoperative Imaging Fund.S

    Synthesis and in vitro evaluation of a multifunctional and surface-switchable nanoemulsion platform

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    We present a multifunctional nanoparticle platform that has targeting moieties shielded by a matrix metalloproteinase-2 (MMP2) cleavable PEG coating. Upon incubation with MMP2 this surface-switchable coating is removed and the targeting ligands become available for binding. The concept was evaluated in vitro using biotin and αvβ3-integrin-specific RGD-peptide functionalized nanoparticles.National Heart, Lung, and Blood InstituteNational Institutes of Health (U.S.) (Program of Excellence in Nanotechnology (PEN) Award Contract HHSN268201000045C

    Evaluating the systemic right ventricle by CMR: the importance of consistent and reproducible delineation of the cavity

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    Contains fulltext : 70334.pdf (publisher's version ) (Open Access)BACKGROUND: The method used to delineate the boundary of the right ventricle (RV), relative to the trabeculations and papillary muscles in cardiovascular magnetic resonance (CMR) ventricular volume analysis, may matter more when these structures are hypertrophied than in individuals with normal cardiovascular anatomy. This study aimed to compare two methods of cavity delineation in patients with systemic RV. METHODS: Twenty-nine patients (mean age 34.7 +/- 12.4 years) with a systemic RV (12 with congenitally corrected transposition of the great arteries (ccTGA) and 17 with atrially switched (TGA) underwent CMR. We compared measurements of systemic RV volumes and function using two analysis protocols. The RV trabeculations and papillary muscles were either included in the calculated blood volume, the boundary drawn immediately within the apparently compacted myocardial layer, or they were manually outlined and excluded. RV stroke volume (SV) calculated using each method was compared with corresponding left ventricular (LV) SV. Additionally, we compared the differences in analysis time, and in intra- and inter-observer variability between the two methods. Paired samples t-test was used to test for differences in volumes, function and analysis time between the two methods. Differences in intra- and inter-observer reproducibility were tested using an extension of the Bland-Altman method. RESULTS: The inclusion of trabeculations and papillary muscles in the ventricular volume resulted in higher values for systemic RV end diastolic volume (mean difference 28.7 +/- 10.6 ml, p < 0.001) and for end systolic volume (mean difference 31.0 +/- 11.5 ml, p < 0.001). Values for ejection fraction were significantly lower (mean difference -7.4 +/- 3.9%, p < 0.001) if structures were included. LV SV did not differ significantly from RV SV for both analysis methods (p = NS). Including structures resulted in shorter analysis time (p < 0.001), and showed better inter-observer reproducibility for ejection fraction (p < 0.01). CONCLUSION: The choice of method for systemic RV cavity delineation significantly affected volume measurements, given the CMR acquisition and analysis systems used. We recommend delineation outside the trabeculations for routine clinical measurements of systemic RV volumes as this approach took less time and gave more reproducible measurements

    High-resolution analysis of HLA class I alterations in colorectal cancer

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    BACKGROUND: Previous studies indicate that alterations in Human Leukocyte Antigen (HLA) class I expression are frequent in colorectal tumors. This would suggest serious limitations for immunotherapy-based strategies involving T-cell recognition. Distinct patterns of HLA surface expression might conceal different immune escape mechanisms employed by the tumors and are worth further study. METHOD: We applied four-color multiparameter flow cytometry (FCM), using a large panel of alloantigen-specific anti-HLA-A and -B monoclonal antibodies, to study membranous expression of individual HLA alleles in freshly isolated colorectal cancer cell suspensions from 21 patients. RESULTS: Alterations in HLA class I phenotype were observed in 8 (38%) of the 21 tumors and comprised loss of a single A or B alleles in 4 cases, and loss of all four A and B alleles in the other 4 cases. Seven of these 8 tumors were located on the right side of the colon, and those showing loss of both HLA-A and -B membranous expression were all of the MSI-H phenotype. CONCLUSION: FCM allows the discrimination of complex phenotypes related to the expression of HLA class I. The different patterns of HLA class I expression might underlie different tumor behavior and influence the success rate of immunotherapy

    Acquisition and clearance of perianal human papillomavirus infection in relation to HIV-positivity in men who have sex with men in the Netherlands

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    This study was performed to establish the prevalence of perianal human papillomavirus (HPV) infection in relation to HIV-positivity in a group of men who have sex with men (MSM), and to correlate follow-up data with regard to acquisition and clearance of HPV infection. Data with regard to HPV prevalence and HIV serostatus during two visits were compared. At both visits participants underwent a routine venereological examination and swabs were taken from the perianal region for HPV DNA testing. During both visits HPV types 16, 18, 31, 33 and 52 were significantly more often detected in HIV-positive individuals. Persistence of HPV type 31 at the perianal region was significantly more often seen in HIV-positive MSM (p=0.036) while the incidence of type 16 may be associated with HIV positivity (p=0.059). In HIV-positive MSM significantly more high-risk HPV types were detected at the perianal region

    An Antiproton Decelerator in the CERN PS Complex

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    The present CERN PS low-energy antiproton complex involves 4 machines to collect, cool, decelerate and supply experiments with up to 1010 antiprotons per pulse and per hour of momenta ranging from 0.1 to 2 GeV/c. In view of a possible future physics programme requiring low energy antiprotons, mainly to carry out studies on antihydrogen, a simplified scheme providing at low cost antiprotons at 100 MeV/c has been studied. It requires only one machine, the present Antiproton Collector (AC) converted into a cooler and decelerator (Antiproton Decelerator, AD) and delivering beam to experiments in the hall of the present Antiproton Accumulator Complex (AAC) [1]. This paper describes the feasibility study of such a scheme [2]

    Nanomedical Theranostics in Cardiovascular Disease

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    Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. New diagnostic and therapeutic strategies are needed to mitigate this public health issue. Advances in nanotechnology have generated innovative strategies for diagnosis and therapy in a variety of diseases, foremost in cancer. Based on these studies, a novel concept referred to as nanomedical theranostics, or the combinatory application of nanoparticulate agents to allow diagnostic therapy, is being explored to enable image-guided, personalized, or targeted treatment. Preclinically, theranostics have been gradually applied to CVD with several interesting and encouraging findings. This article summarizes studies and challenges of nanotheranostic strategies in CVD. It also evaluates nanotheranostic strategies that may potentially be utilized to benefit patients
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