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Label-Free Composition Analysis of Supramolecular Polymer-Nanoparticle Hydrogels by Reversed-Phase Liquid Chromatography Coupled with a Charged Aerosol Detector. Anal Chem 2024; 96:5860-5868. [PMID: 38567987 DOI: 10.1021/acs.analchem.3c05747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Supramolecular hydrogels formed through polymer-nanoparticle interactions are promising biocompatible materials for translational medicines. This class of hydrogels exhibits shear-thinning behavior and rapid recovery of mechanical properties, providing desirable attributes for formulating sprayable and injectable therapeutics. Characterization of hydrogel composition and loading of encapsulated drugs is critical to achieving the desired rheological behavior as well as tunable in vitro and in vivo payload release kinetics. However, quantitation of hydrogel composition is challenging due to material complexity, heterogeneity, high molecular weight, and the lack of chromophores. Here, we present a label-free approach to simultaneously determine hydrogel polymeric components and encapsulated payloads by coupling a reversed phase liquid chromatographic method with a charged aerosol detector (RPLC-CAD). The hydrogel studied consists of modified hydroxypropylmethylcellulose, self-assembled PEG-b-PLA nanoparticles, and a therapeutic compound, bimatoprost. The three components were resolved and quantitated using the RPLC-CAD method with a C4 stationary phase. The method demonstrated robust performance, applicability to alternative cargos (i.e., proteins) and was suitable for composition analysis as well as for evaluating in vitro release of cargos from the hydrogel. Moreover, this method can be used to monitor polymer degradation and material stability, which can be further elucidated by coupling the RPLC method with (1) a multi-angle light scattering detector (RPLC-MALS) or (2) high resolution mass spectrometry (RPLC-MS) and a Fourier-transform based deconvolution algorithm. We envision that this analytical strategy could be generalized to characterize critical quality attributes of other classes of supramolecular hydrogels, establish structure-property relationships, and provide rational design guidance in hydrogel drug product development.
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Nanoparticle-Conjugated Toll-Like Receptor 9 Agonists Improve the Potency, Durability, and Breadth of COVID-19 Vaccines. ACS NANO 2024; 18:3214-3233. [PMID: 38215338 PMCID: PMC10832347 DOI: 10.1021/acsnano.3c09700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 01/04/2024] [Accepted: 01/09/2024] [Indexed: 01/14/2024]
Abstract
Development of effective vaccines for infectious diseases has been one of the most successful global health interventions in history. Though, while ideal subunit vaccines strongly rely on antigen and adjuvant(s) selection, the mode and time scale of exposure to the immune system has often been overlooked. Unfortunately, poor control over the delivery of many adjuvants, which play a key role in enhancing the quality and potency of immune responses, can limit their efficacy and cause off-target toxicities. There is a critical need for improved adjuvant delivery technologies to enhance their efficacy and boost vaccine performance. Nanoparticles have been shown to be ideal carriers for improving antigen delivery due to their shape and size, which mimic viral structures but have been generally less explored for adjuvant delivery. Here, we describe the design of self-assembled poly(ethylene glycol)-b-poly(lactic acid) nanoparticles decorated with CpG, a potent TLR9 agonist, to increase adjuvanticity in COVID-19 vaccines. By controlling the surface density of CpG, we show that intermediate valency is a key factor for TLR9 activation of immune cells. When delivered with the SARS-CoV-2 spike protein, CpG nanoparticle (CpG-NP) adjuvant greatly improves the magnitude and duration of antibody responses when compared to soluble CpG, and results in overall greater breadth of immunity against variants of concern. Moreover, encapsulation of CpG-NP into injectable polymeric-nanoparticle (PNP) hydrogels enhances the spatiotemporal control over codelivery of CpG-NP adjuvant and spike protein antigen such that a single immunization of hydrogel-based vaccines generates humoral responses comparable to those of a typical prime-boost regimen of soluble vaccines. These delivery technologies can potentially reduce the costs and burden of clinical vaccination, both of which are key elements in fighting a pandemic.
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Saponin Nanoparticle Adjuvants Incorporating Toll-Like Receptor Agonists Improve Vaccine Immunomodulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.16.549249. [PMID: 37577608 PMCID: PMC10418080 DOI: 10.1101/2023.07.16.549249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Over the past few decades, the development of potent and safe immune-activating adjuvant technologies has become the heart of intensive research in the constant fight against highly mutative and immune evasive viruses such as influenza, SARS-CoV-2, and HIV. Herein, we developed a highly modular saponin-based nanoparticle platform incorporating toll-like receptor agonists (TLRas) including TLR1/2a, TLR4a, TLR7/8a adjuvants and their mixtures. These various TLRa-SNP adjuvant constructs induce unique acute cytokine and immune-signaling profiles, leading to specific Th-responses that could be of interest depending on the target disease for prevention. In a murine vaccine study, the adjuvants greatly improved the potency, durability, breadth, and neutralization of both COVID-19 and HIV vaccine candidates, suggesting the potential broad application of these adjuvant constructs to a range of different antigens. Overall, this work demonstrates a modular TLRa-SNP adjuvant platform which could improve the design of vaccines for and dramatically impact modern vaccine development.
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Broad and Durable Humoral Responses Following Single Hydrogel Immunization of SARS-CoV-2 Subunit Vaccine. Adv Healthc Mater 2023; 12:e2301495. [PMID: 37278391 DOI: 10.1002/adhm.202301495] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Indexed: 06/07/2023]
Abstract
Most vaccines require several immunizations to induce robust immunity, and indeed, most SARS-CoV-2 vaccines require an initial two-shot regimen followed by several boosters to maintain efficacy. Such a complex series of immunizations unfortunately increases the cost and complexity of populations-scale vaccination and reduces overall compliance and vaccination rate. In a rapidly evolving pandemic affected by the spread of immune-escaping variants, there is an urgent need to develop vaccines capable of providing robust and durable immunity. In this work, a single immunization SARS-CoV-2 subunit vaccine is developed that can rapidly generate potent, broad, and durable humoral immunity. Injectable polymer-nanoparticle (PNP) hydrogels are leveraged as a depot technology for the sustained delivery of a nanoparticle antigen (RND-NP) displaying multiple copies of the SARS-CoV-2 receptor-binding domain (RBD) and potent adjuvants including CpG and 3M-052. Compared to a clinically relevant prime-boost regimen with soluble vaccines formulated with CpG/alum or 3M-052/alum adjuvants, PNP hydrogel vaccines more rapidly generated higher, broader, and more durable antibody responses. Additionally, these single-immunization hydrogel-based vaccines elicit potent and consistent neutralizing responses. Overall, it is shown that PNP hydrogels elicit improved anti-COVID immune responses with only a single administration, demonstrating their potential as critical technologies to enhance overall pandemic readiness.
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Label-Free Composition Analysis of Supramolecular Polymer - Nanoparticle Hydrogels by Reversed-Phase Liquid Chromatography Coupled with a Charged Aerosol Detector. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.11.553055. [PMID: 37609276 PMCID: PMC10441420 DOI: 10.1101/2023.08.11.553055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Supramolecular hydrogels formed through polymer-nanoparticle interactions are promising biocompatible materials for translational medicines. This class of hydrogels exhibits shear-thinning behavior and rapid recovery of mechanical properties following applied stresses, providing desirable attributes for formulating sprayable and injectable therapeutics. Characterization of hydrogel composition and loading of encapsulated drugs is critical to achieving desired rheological behavior as well as tunable in vitro and in vivo payload release kinetics. However, quantitation of hydrogel compositions is challenging due to material complexity, heterogeneity, high molecular weight, and the lack of chromophores. Here, we present a label-free approach to simultaneously determine hydrogel polymeric components and encapsulated payloads by coupling a reversed phase liquid chromatographic method with a charged aerosol detector (RPLC-CAD). The hydrogel studied consists of modified hydroxypropylmethylcellulose, self-assembled PEG-b-PLA nanoparticles, and a therapeutic compound, Bimatoprost. The three components were resolved and quantitated using the RPLC-CAD method with a C4 stationary phase. The method demonstrated robust performance, applicability to alternative cargos (i.e. proteins), and was suitable for composition analysis as well as for evaluating in vitro release of cargos from the hydrogel. Moreover, this method can be used to monitor polymer degradation and material stability, which can be further elucidated by coupling the RPLC method with high resolution mass spectrometry and a Fourier-transform based deconvolution algorithm. To our knowledge, this is the first RPLC-CAD method for characterizing the critical quality attributes of supramolecular hydrogels. We envision this analytical strategy could be generalized to characterize other classes of supramolecular hydrogels, establish structure-property relationships, and provide rational design guidance in hydrogel drug product development.
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Stable High-Concentration Monoclonal Antibody Formulations Enabled by an Amphiphilic Copolymer Excipient. ADVANCED THERAPEUTICS 2023; 6:2200102. [PMID: 36684707 PMCID: PMC9854243 DOI: 10.1002/adtp.202200102] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Monoclonal antibodies are a staple in modern pharmacotherapy. Unfortunately, these biopharmaceuticals are limited by their tendency to aggregate in formulation, resulting in poor stability and often requiring low concentration drug formulations. Moreover, existing excipients designed to stabilize these formulations are often limited by their toxicity and tendency to form particles such as micelles. Here, we demonstrate the ability of a simple "drop-in", amphiphilic copolymer excipient to enhance the stability of high concentration formulations of clinically-relevant monoclonal antibodies without altering their pharmacokinetics or injectability. Through interfacial rheology and surface tension measurements, we demonstrate that the copolymer excipient competitively adsorbs to formulation interfaces. Further, through determination of monomeric composition and retained bioactivity through stressed aging, we show that this excipient confers a significant stability benefit to high concentration antibody formulations. Finally, we demonstrate that the excipient behaves as an inactive ingredient, having no significant impact on the pharmacokinetic profile of a clinically relevant antibody in mice. This amphiphilic copolymer excipient demonstrates promise as a simple formulation additive to create stable, high concentration antibody formulations, thereby enabling improved treatment options such as a route-of-administration switch from low concentration intravenous (IV) to high concentration subcutaneous (SC) delivery while reducing dependence on the cold chain.
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Extreme Extensibility in Physically Cross-Linked Nanocomposite Hydrogels Leveraging Dynamic Polymer–Nanoparticle Interactions. Macromolecules 2022; 55:7498-7511. [PMID: 36118599 PMCID: PMC9476865 DOI: 10.1021/acs.macromol.2c00649] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 08/02/2022] [Indexed: 11/28/2022]
Abstract
![]()
Designing yield stress fluids to exhibit desired functional
properties
is an integral challenge in many applications such as 3D printing,
drilling, food formulation, fiber spinning, adhesives, and injectable
biomaterials. Extensibility in particular has been found to be a highly
beneficial characteristic for materials in these applications; however,
few highly extensible, high water content materials have been reported
to date. Herein we engineer a class of high water content nanocomposite
hydrogel materials leveraging multivalent, noncovalent, polymer–nanoparticle
(PNP) interactions between modified cellulose polymers and biodegradable
nanoparticles. We show that modulation of the chemical composition
of the PNP hydrogels controls the dynamic cross-linking interactions
within the polymer network and directly impacts yielding and viscoelastic
responses. These materials can be engineered to stretch up to 2000%
strain and occupy an unprecedented property regime for extensible
yield stress fluids. Moreover, a dimensional analysis of the relationships
between extensibility and the relaxation and recovery time scales
of these nanocomposite hydrogels uncovers generalizable design criteria
that will be critical for future development of extensible materials.
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Sustained delivery approaches to improving adaptive immune responses. Adv Drug Deliv Rev 2022; 187:114401. [PMID: 35750115 DOI: 10.1016/j.addr.2022.114401] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 06/14/2022] [Accepted: 06/17/2022] [Indexed: 11/17/2022]
Abstract
The immune system is one of the most important, complex biological networks regulating and protecting human health. Its precise modulation can prevent deadly infections and fight cancer. Accordingly, prophylactic vaccines and cancer immunotherapies are some of the most powerful technologies to protect against potential dangers through training of the immune system. Upon immunization, activation and maturation of B and T cells of the adaptive immune system are necessary for development of proper humoral and cellular protection. Yet, the exquisite organization of the immune system requires spatiotemporal control over the exposure of immunomodulatory signals. For example, while the human immune system has evolved to develop immunity to natural pathogenic infections that often last for weeks, current prophylactic vaccination technologies only expose the immune system to immunomodulatory signals for hours to days. It has become clear that leveraging sustained release technologies to prolong immunogen and adjuvant exposure can increase the potency, durability, and quality of adaptive immune responses. Over the past several years, tremendous breakthroughs have been made in the design of novel biomaterials such as nanoparticles, microparticles, hydrogels, and microneedles that can precisely control and the presentation of immunomodulatory signals to the immune system. In this review, we discuss relevant sustained release strategies and their corresponding benefits to cellular and humoral responses.
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Consistent tumorigenesis with self-assembled hydrogels enables high-powered murine cancer studies. Commun Biol 2021; 4:985. [PMID: 34413455 PMCID: PMC8376877 DOI: 10.1038/s42003-021-02500-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 07/21/2021] [Indexed: 01/05/2023] Open
Abstract
Preclinical cancer research is heavily dependent on allograft and xenograft models, but current approaches to tumor inoculation yield inconsistent tumor formation and growth, ultimately wasting valuable resources (e.g., animals, time, and money) and limiting experimental progress. Here we demonstrate a method for tumor inoculation using self-assembled hydrogels to reliably generate tumors with low variance in growth. The observed reduction in model variance enables smaller animal cohorts, improved effect observation and higher powered studies.
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β-Galactosidase instructed self-assembly of supramolecular bolaamphiphiles hydrogelators. SOFT MATTER 2020; 16:7648-7651. [PMID: 32657300 DOI: 10.1039/d0sm01055c] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
β-Galactosidase instructed supramolecular assemblies of Low Molecular Weight Gelators (LMWGs) derived from glyconucleo-bolaamphiphiles have been designed. These precursors, comprising galactose sensitive units at both polar heads, showed the formation of hydrogels upon the action of β-galactosidase.
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Supramolecular gels derived from nucleoside based bolaamphiphiles as a light-sensitive soft material. Chem Commun (Camb) 2020; 56:3397-3400. [PMID: 32091070 DOI: 10.1039/d0cc00336k] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Light-sensitive Low Molecular Weight Gelators (LMWGs) derived from glyconucleoside bolaamphiphiles containing a stilbene unit displayed gelation abilities in hydroalcoholic mixtures. These materials showed a gel-sol transition under UV irradiation thanks to E-Z isomerization of stilbene and could find potential applications as drug delivery systems.
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13
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Correction: Supramolecular gels derived from nucleoside based bolaamphiphiles as a light-sensitive soft material. Chem Commun (Camb) 2020; 56:9569. [DOI: 10.1039/d0cc90331k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Correction for ‘Supramolecular gels derived from nucleoside based bolaamphiphiles as a light-sensitive soft material’ by Julie Baillet et al., Chem. Commun., 2020, 56, 3397–3400, DOI: 10.1039/D0CC00336K.
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Lipid and Nucleic Acid Chemistries: Combining the Best of Both Worlds to Construct Advanced Biomaterials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:1705078. [PMID: 29341288 DOI: 10.1002/adma.201705078] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 10/20/2017] [Indexed: 06/07/2023]
Abstract
Hybrid synthetic amphiphilic biomolecules are emerging as promising supramolecular materials for biomedical and technological applications. Herein, recent progress in the field of nucleic acid based lipids is highlighted with an emphasis on their molecular design, synthesis, supramolecular properties, physicochemical behaviors, and applications in the field of health science and technology. In the first section, the design and the study of nucleolipids are in focus and then the glyconucleolipid family is discussed. In the last section, recent contributions of responsive materials involving nucleolipids and their use as smart drug delivery systems are discussed. The supramolecular materials generated by nucleic acid based lipids open new challenges for biomedical applications, including the fields of medicinal chemistry, biosensors, biomaterials for tissue engineering, drug delivery, and the decontamination of nanoparticles.
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Untersuchungen zur Bestimmung der kapillaren Durchlässigkeit mit markiertem menschlichem Albumin. Nuklearmedizin 2018. [DOI: 10.1055/s-0038-1624964] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
ZusammenfassungMit dieser Studie stellen wir einen neuen Test vor, durch den die kapillare Durchlässigkeit unter Verwendung von markierten Albuminen näher bestimmt wird.Seine Methode ist einfach, die Ergebnisse sind sehr zufriedenstellend und ermöglichen eine gute Distanzierung von gesunden und pathologischen Personen. Bei gesunden Personen sinkt nach dem Entfernen der Armpresse die Aktivitätsmenge auf die vor dem Anbringen der Armpresse beobachteten Werte.Bei pathologischen Personen mit Ödem wird dagegen in den 6 Minuten, die dem Entfernen der Armpresse folgen, kein Rückgang zu früheren Werten verzeichnet. Die Retention von markierten Albuminen ist immer über 10%.Der Test ist besonders aufschlußreich bei zyklischem Ödem.
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16
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Data on iron oxide core oil-in-water nanoemulsions for atherosclerosis imaging. Data Brief 2017; 15:876-881. [PMID: 29159224 PMCID: PMC5675726 DOI: 10.1016/j.dib.2017.10.059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/13/2017] [Accepted: 10/23/2017] [Indexed: 11/23/2022] Open
Abstract
The data presented in this article are related to the publication entitled "Iron oxide core oil-in-water nanoemulsion as tracer for atherosclerosis MPI and MRI imaging" (Prévot et al., 2017) [1]. Herein we describe the synthesis and the characteristics of the Superparamagnetic Iron Oxide Nanoparticles (SPION) loaded inside nanoemulsions (NEs). Focus was set on obtaining SPION with narrow size distribution and close to superparamagnetic limit (20 nm) in order to reach a reasonable magnetic signal. Nanoparticles (NPs) of three different sizes were obtained (7, 11 and 18 nm) and characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), diffuse reflectance infrared Fourier transform (DRIFT) and thermogravimetric analysis (TGA). SPION were coated with oleic acid (OA) in order to load them inside the oily core of NEs droplets. SPION loaded NEs were magnetically sorted using MACS® MS Column (Miltenyi Biotec) and iron quantification was performed by UV-spectrometry measurements.
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17
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Iron oxide core oil-in-water nanoemulsion as tracer for atherosclerosis MPI and MRI imaging. Int J Pharm 2017; 532:669-676. [PMID: 28899764 DOI: 10.1016/j.ijpharm.2017.09.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 09/04/2017] [Accepted: 09/05/2017] [Indexed: 12/20/2022]
Abstract
PURPOSE For early atherosclerosis imaging, magnetic oil-in-water nanoemulsion (NE) decorated with atheroma specific monoclonal antibody was designed for Magnetic Particle Imaging (MPI) and Magnetic Resonance Imaging (MRI). MPI is an emerging technique based on direct mapping of superparamagnetic nanoparticles which may advantageously complement MRI. METHODS NE oily droplets were loaded with superparamagnetic iron oxide nanoparticles of 7, 11 and 18nm and biofunctionalized with atheroma specific scFv-Fc TEG4-2C antibody. RESULTS Inclusion of nanoparticles inside NE did not change the hydrodynamic diameter of the oil droplets, close to 180nm, nor the polydispersity. The droplets were negatively charged (ζ=-30mV). In vitro MPI signal was assessed by Magnetic Particle Spectroscopy (MPS). NE displayed MRI and MPS signals confirming its potential as new contrast agent. NE MPS signal increase with NPs size close to the gold standard (Resovist). In MRI, NE displayed R2* transversal relaxivity of 45.45, 96.04 and 218.81mM-1s-1 for 7, 11 and 18nm respectively. NE selectively bind atheroma plaque both in vitro and ex vivo in animal models of atherosclerosis. CONCLUSION Magnetic NE showed reasonable MRI/MPS signals and a significant labelling of the atheroma plaque. These preliminary results support that NE platform could selectively image atherosclerosis.
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18
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Carbamate-Based Bolaamphiphile as Low-Molecular-Weight Hydrogelators. Gels 2016; 2:gels2040025. [PMID: 30674156 PMCID: PMC6318576 DOI: 10.3390/gels2040025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 09/21/2016] [Accepted: 09/22/2016] [Indexed: 11/16/2022] Open
Abstract
A new bolaamphiphile analog featuring carbamate moieties was synthesized in six steps starting from thymidine. The amphiphile structure exhibits nucleoside-sugar polar heads attached to a hydrophobic spacer via carbamate (urethane) functions. This molecular structure, which possesses additional H-bonding capabilities, induces the stabilization of low-molecular-weight gels (LMWGs) in water. The rheological studies revealed that the new bolaamphiphile 7 stabilizes thixotropic hydrogels with a high elastic modulus (G′ > 50 kPa).
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19
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Abstract
A new low molecular weight alcogel based on glycosyl-nucleoside-lipids is reported. This material features high elastic moduli and thixotropic properties.
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20
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Anévrysme infectieux de l'aorte thoracique postartériographie par voie numérale. Rev Med Interne 1999. [DOI: 10.1016/s0248-8663(99)80264-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Accidents exposant au sang au CHU d'Amiens: résultats de un an de surveillance. Rev Med Interne 1999. [DOI: 10.1016/s0248-8663(99)80179-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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22
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Lymphomes des sujets âgés: expérience d'un service de médecine interne. Rev Med Interne 1998. [DOI: 10.1016/s0248-8663(98)80017-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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23
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Un myélome rare: le myélome à IgD. À propos de deux cas. Rev Med Interne 1998. [DOI: 10.1016/s0248-8663(98)80197-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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24
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Une atteinte surrénalienne rare: le lymphome à grandes cellules. Rev Med Interne 1998. [DOI: 10.1016/s0248-8663(98)80167-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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25
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La candidose grave de l’héroïnomane. À propos d’un cas. Rev Med Interne 1997. [DOI: 10.1016/s0248-8663(97)80081-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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26
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27
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Une arthropathie bien destructrice de l'épaule. Rev Med Interne 1996. [DOI: 10.1016/0248-8663(96)87146-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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28
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[Salmonella typhimurium cerebral abscess: rare complication of HIV infection]. Presse Med 1996; 25:556. [PMID: 8731803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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29
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Ténosynovite tuberculeuse. Rev Med Interne 1996. [DOI: 10.1016/s0248-8663(97)81168-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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30
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Enquête prospective sur l'utilisation des antalgiques de niveau II chez les personnes âgées. Rev Med Interne 1996. [DOI: 10.1016/s0248-8663(97)81139-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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31
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La fièvre Q. Rev Med Interne 1995. [DOI: 10.1016/0248-8663(96)86513-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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32
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Traitement des pneumopathies à Chlamydia pneumoniae par la roxithromycine. Rev Med Interne 1995. [DOI: 10.1016/0248-8663(96)86616-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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33
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Pneumopathies communautaires mixtes sévères associant Chlamydia pneumoniae et pneumocoques (deux cas) et Chlamydia pneumoniae et légionnelle (un cas). Rev Med Interne 1995. [DOI: 10.1016/0248-8663(96)86615-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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34
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Pneumopathies communautaires de l'adulte. Rev Med Interne 1995. [DOI: 10.1016/0248-8663(96)86519-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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35
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Deux nouveaux cas de Hodgkin compliquant une sarcoïdose: diagnostic erroné ou lien pathogénique ? Rev Med Interne 1995. [DOI: 10.1016/0248-8663(96)86715-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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36
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Pneumopathies à Chlamydia pneumoniae. Rev Med Interne 1995. [DOI: 10.1016/0248-8663(96)86510-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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37
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La Médecine serait facile s'il n'y avait pas les malades. Rev Med Interne 1995. [DOI: 10.1016/0248-8663(96)86487-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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38
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[Subjectivity in the reading of scientific articles]. ARCHIVES DES MALADIES DU COEUR ET DES VAISSEAUX 1994; 87 Spec No 4:79-82. [PMID: 7786140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
With the examples of historical incoherencies in the diagnosis and treatment of myocardial infarction and pulmonary embolism, the author shows that it is not easy to be an objective reader of "good" scientific articles. Our neuropsychological mechanisms do not facilitate an "intelligent" attitude without the aid of affectivity. An unwanted thymotic component places the reader in an ambiguous position with respect to authority and reality. Though one can never know too much, it is difficult, alone, to maintain an intelligent curiosity. Some financial interests may awaken it. During his career, the physician has to navigate between two slightly contradictory necessities: changing his attitude with respect to new information, and according credence to his personal experience.
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Abstract
Biliary tubage, is interesting in the aetiological research of acute pancreatitis, when the origin is unknown after anamnesis, clinical examination, abdominal ultrasonographic studies and retrograde cholangiography. The sludge is the aetiology fond in 40% of the cases. Microscopic crystals are either cholesterol monohydrate, either calcium bilirubinate, or calcium carbonate microspheroliths. Biliary microscopic crystals drive the patients to the cholecystectomy to prevent acute pancreatitis relapses.
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40
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Syndrome de Melkerson-Rosenthal. Rev Med Interne 1994. [DOI: 10.1016/s0248-8663(05)82781-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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42
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[Thrombopenia following treatment with omeprazole]. Presse Med 1993; 22:966. [PMID: 8367424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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P 013 Bowel perforation in the course of Behçet's disease. Rev Med Interne 1993. [DOI: 10.1016/s0248-8663(05)82315-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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44
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Abstract
In familial adenomatous polyposis coli (APC) it is possible to detect APC carriers either by research of bilateral congenital hypertrophy of the retinal pigment epithelium (CHRPE) or by genetic diagnosis (APC gene is localized in 5q21). These detections were performed in 33 patients of four families with the same positivity for genetic typing (11 patients) or for CHRPE (11 patients) which thus avoided annual coloscopy.
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Gastrite folliculaire et Helicobacter pylori. Rev Med Interne 1992. [DOI: 10.1016/s0248-8663(05)81107-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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46
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Pathology. Ir J Med Sci 1992. [DOI: 10.1007/bf02942888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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47
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[Pneumopathies caused by Chlamydia pneumoniae]. Presse Med 1992; 21:1064-9. [PMID: 1326110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Among the atypical pneumonias observed between March 1990 and March 1991, 6 were diagnosed as being caused by Chlamydia pneumoniae of the TWAR strain. The serological diagnosis was obtained by a microimmunofluorescence test. All 6 patients had anti-TWAR antibody levels higher than 512; they were treated with a macrolide administered by the oral route and were cured without sequelae or recurrences. Four cases received a ten day course of roxithromycin 300 mg/day and one case received erythromycin 2 g/day also for 10 days. The sixth case received a short course of azithromycin 500 mg once daily for three days. In 2 other patients presenting with clinical and radiological signs of pneumonia the diagnosis of C. pneumoniae infection could not be made despite an antibody level equal or higher than 512, since the serological results showed cross-reactions between C. pneumoniae, C. trachomatis and C. psittaci antibody responses.
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Uvéite en médecine interne. Rev Med Interne 1992. [DOI: 10.1016/s0248-8663(05)81536-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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49
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[Pulmonary metastasis of meningioma of the falx cerebri]. Rev Med Interne 1992; 13:142-4. [PMID: 1410888 DOI: 10.1016/s0248-8663(05)82198-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We report the case of a woman who had been operated upon for a recurrent meningioma of the falx cerebri which, 22 years after it was discovered, produced pulmonary metastases. Metastases from meningiomas are extremely rare; they affect the lungs in 60% of the cases or, less frequently, the liver or lymph nodes. The factors predictive of secondary dissemination are the site of the tumour, the quality of excision, the histological type (haemangiopericytic meningioma) and the presence of cell necrosis, hypercellularity and strong mitotic activity.
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Abstract
The pharmacokinetics of piperacillin were evaluated in seven healthy volunteers, eight cirrhotic patients without ascites and 11 cirrhotic patients with sterile ascites after a single 15-min intravenous infusion of 4 g of the drug. In ascitic patients, piperacillin rapidly entered the peritoneal fluid. Peritoneal concentrations were higher than 10 mg/l from 0.5 to 8 h after the infusion. Disappearance rate of piperacillin was slower in the ascitic fluid than in plasma. The plasma half life of piperacillin was more prolonged in cirrhotic patients that in control subjects. This difference was more marked in ascitic patients for whom half life was twice as high as in volunteers (1.95 versus 0.91 h; P less than 0.01).
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