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1.
J Infect Dis ; 228(6): 694-703, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-36932045

RESUMO

BACKGROUND: Alpha kinase 1 (ALPK1) agonist has recently been reported to demonstrate anti-hepatitis B virus (HBV) efficacy via activating NF-κB signaling, which is crucial for maximizing interferon (IFN) responses. Here, we investigated the impact of ALPK1 on HBV replication and explored ALPK1 variants for predicting the response to pegylated IFN-α (PegIFN-α) treatment. METHODS: The potential anti-HBV effect of ALPK1 was evaluated in HBV-integrated and HBV-infected hepatoma cells. The potentially functional genetic variants of ALPK1 were screened out, and their correlations with PegIFN-α treatment response were assessed in 945 hepatitis B e antigen (HBeAg)-positive patients with chronic hepatitis B (CHB). RESULTS: We revealed that ALPK1 inhibited HBV replication in hepatocytes via activating the JAK-STAT pathway. ALPK1 overexpression improved the anti-HBV effect of IFN-α in cell models. A missense variant, rs35389530 (P660L), of ALPK1 was strongly associated with combined response (CR; namely, HBeAg seroconversion and HBV DNA level <3.3log10 IU/mL) to PegIFN-α treatment in patients with CHB (P = 2.12 × 10-6). Moreover, a polygenic score integrating ALPK1_rs35389530 and 2 additional genetic variants was further significantly associated with CR (Ptrend = 9.28 × 10-7), hepatitis B surface antigen (HBsAg) level (Ptrend = .0002), and HBsAg loss (Ptrend = .025). CONCLUSIONS: The anti-HBV effects of ALPK1 through activating JAK-STAT pathway provides a new perspective for CHB therapy. ALPK1_rs35389530 and polygenic score are potential biomarkers to predict PegIFN-α treatment response and may be used for optimizing CHB treatment.


Assuntos
Vírus da Hepatite B , Hepatite B Crônica , Humanos , Vírus da Hepatite B/genética , Antivirais/farmacologia , Antivirais/uso terapêutico , Antígenos de Superfície da Hepatite B/uso terapêutico , Antígenos E da Hepatite B , Janus Quinases/uso terapêutico , Fatores de Transcrição STAT/uso terapêutico , Transdução de Sinais , Interferon-alfa/farmacologia , Interferon-alfa/uso terapêutico , DNA Viral , Polietilenoglicóis/uso terapêutico , Replicação Viral , Resultado do Tratamento
2.
Clin Gastroenterol Hepatol ; 18(1): 196-204.e8, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31042581

RESUMO

BACKGROUND & AIMS: Variants in STAT4 (rs7574865) have been associated with seroconversion to hepatitis B e antigen (HBeAg) and reduction in levels of hepatitis B virus (HBV) DNA in patients with chronic infection treated with interferon alpha (IFNA). We evaluated the associations among rs7574865, loss of HB surface antigen (HBsAg, a marker of functional cure of HBV infection), and response to treatment with pegylated IFNA (PegIFN) or nucleos(t)ide analogues (NUCs) in HBeAg-positive patients with chronic HBV infection. METHODS: We performed a retrospective analysis of 1823 HBeAg-positive patients with chronic HBV infection (954 patients treated with PegIFN and 869 patients treated with NUCs) included in 4 phase-4 multicenter randomized controlled trials. The Cochran-Armitage trend test was used to evaluate the association of rs7574865 genotype with combined response (CR, defined as HBeAg seroconversion and HBV DNA level <2000 IU/mL) and loss of HBsAg at week 72, for patients given PegIFN, or week 104, for patients given NUCs. RESULTS: We found a significant association between rs7574865 genotype and CR (P = .004) and loss of HBsAg (P = .037) in patients treated with PegIFN. In patients with HBV genotype B infection, 43.6% of those with rs7574865 TT achieved a CR, compared to patients with rs7574865 GG (20.5%), and 7.7% had loss of HBsAg, compared to 1.9% of patients with rs7574865 GG. However, in patients treated with NUCs, we found no association of rs7574865 genotype with CR (P = .811) or loss of HBsAg (P=.439). CONCLUSIONS: In a retrospective analysis of data from 4 clinical trials, we found rs7574865 in STAT4 to be associated with functional cure of chronic HBV infection by PegIFN treatment, but not NUCs treatment, in HBeAg-positive patients with HBV genotype B infection.


Assuntos
Antivirais/uso terapêutico , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/genética , Interferon-alfa/uso terapêutico , Fator de Transcrição STAT4/genética , Adulto , DNA Viral/análise , Feminino , Genótipo , Antígenos E da Hepatite B/imunologia , Hepatite B Crônica/imunologia , Humanos , Masculino , Nucleosídeos/uso terapêutico , Nucleotídeos/uso terapêutico , Polietilenoglicóis/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Proteínas Recombinantes/uso terapêutico , Estudos Retrospectivos , Soroconversão , Adulto Jovem
3.
Inhal Toxicol ; 32(9-10): 388-401, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-33043732

RESUMO

OBJECTIVE: The growing applications of nanocelluloses in the fields of advanced nanocomposites, electronics, and medical devices necessitate investigation of their potential adverse effects on human health. The lungs are the primary and the most important route for the entry of nanocelluloses into the human body in occupational settings. However, data on the pulmonary toxicity of cellulose nanofibrils (CNFs) and its molecular mechanism are limited. This study investigated the pulmonary toxicity of CNFs and its genomic expression using the RNA sequencing approach. MATERIALS AND METHODS: Female C57BL/6 mice were administered CNFs at 50 µg/mouse by oropharyngeal aspiration. Samples were collected at 3 and 14 days after exposure to CNFs (DAEC). RESULTS: At three DAEC, the microscopic sections of lungs revealed a significant inflammatory response. In terms of gene expression alterations, 94 genes were up-regulated, and 107 genes were down-regulated. Most of these differentially expressed genes were involved in the inflammatory and immune responses, including chemokines, NK cells, killer cell lectin-like receptors, CD antigens, T cell-specific GTPases, immunity-related GTPase family M members, and interferon-induced proteins encoding genes. However, only 9 and 26 genes at 14 DAEC were significantly up- and down-regulated, respectively. CONCLUSIONS: The pathological analysis of lung sections and the analysis of sequencing data suggested that the homeostasis of mice lungs was restored at 14 DAEC. The findings of this study provide insights into the pulmonary toxicity, and underlying toxicological mechanisms, caused by exposure to CNFs, and are useful for the assessment of the potential toxicity of nanocelluloses.


Assuntos
Celulose/toxicidade , Pulmão/efeitos dos fármacos , Nanofibras/toxicidade , Administração por Inalação , Animais , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/patologia , Camundongos Endogâmicos C57BL
4.
Int J Biol Macromol ; 258(Pt 2): 128965, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38151087

RESUMO

Tobacco mosaic virus (TMV) is the most widely spread and harmful virus in the world, causing serious economic losses annually. However, the low anti-erosion ability of the pesticides for TMV management make it easy to be washed by the rain, which makes the effective duration of the pesticides shorter. In this paper, a new bio-based nanogel with superior antiviral activity was reported, and its slow-release behavior, rain erosion resistance and the antiviral mechanism was systematically studied. The results determined that the nanogels (Zn2+@ALGNP and Zn2+@ALGNP@PL) exhibited sustained releasing of Zn2+ with a 7 days duration, and the ε-PL coating could enhance the releasing rate of Zn2+. Moreover, Zn2+@ALGNP@PL displayed a lower contact angle, indicating greater adhesion to the leaf surface, and in consequence imposed better resistance to simulate rain erosion than pure Zn2+. Strikingly, Zn2+@ALGNP@PL could inhibit plant virus infection by aggregating the virions and reducing its coat protein stability, as well as inducing the efficient expression of reactive oxygen species, antioxidant enzymes and resistance genes to enhance plant resistance and promote plant growth. Overall, this study had successfully developed a high rain-erosion resistant bio-based nanogel capable of continue to induce resistant plants and promote plant growth.


Assuntos
Praguicidas , Polietilenoglicóis , Polietilenoimina , Vírus do Mosaico do Tabaco , Nanogéis , Nicotiana , Doenças das Plantas , Antivirais/farmacologia , Praguicidas/farmacologia
5.
Artigo em Inglês | MEDLINE | ID: mdl-38019760

RESUMO

In the treatment process of cancers like oral cancer, it is necessary to employ extensive surgical resection to achieve cancer eradication. However, this often results in damage to crucial functions such as chewing and speaking, leading to a poorer prognosis and a reduced quality of life. To address this issue, a multifunctional theranostic agent named MBPN-T-BTD has been developed by precisely modulating the excitation state energy distribution in the radiative/nonradiative decay pathways using the characteristics of twisted intramolecular charge transfer and aggregation-induced emission. This agent outperforms clinically utilized indocyanine green (ICG) in various aspects, including the second near-infrared window (NIR-II, 1000-1700 nm) fluorescence (FL) and photothermal conversion efficiency (PCE). Its nanoparticle form (BTB NPs) can be effectively used for high-contrast delineation of lymph node mapping and tongue and floor of mouth cancers using NIR-II FL, enabling surgeons to achieve more precise and thorough tumor clearance. For tumors located in close proximity to vital organs such as the tongue, the exceptional PCE (71.96%) of BTB NPs allows for targeted photothermal ablation with minimal damage to peripheral healthy tissues. This contribution provides a safer and more effective paradigm for minimally invasive or noninvasive treatment of oral cancer, ensuring the preservation of normal organ functions and showing potential for improving the overall prognosis and quality of life for cancer patients.

6.
Int J Biol Macromol ; 223(Pt A): 961-970, 2022 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-36379280

RESUMO

Cold-set interpenetrating polymer network gels as riboflavin (RF) delivery vehicles based on wheat bran arabinoxylans (AX) and pea protein isolate (PPI) were developed via enzymatic-crosslinking. The impact of AX concentrations on the physicochemical property, in vitro digestion property and microstructure of IPN gels was explored. Increased concentrations of AX enhanced the viscoelasticity of IPN gels and resulted in a more compact microstructure. However, at a concentration of 5.0 % (w/v), the faster and stronger crosslinking of AX molecules caused separate network gel between PPI and AX. The IPN gel improved the encapsulation efficiency and release property of embedded RF as compared to PPI gel. SEM results showed that IPN gel maintained a complete network structure after gastric digestion. Particularly, the IPN gel with 1.0 % AX exhibited a homogeneous and complete network structure even after intestinal digestion, which explained the reason for the highest encapsulation efficiency and lowest release ratios of RF.


Assuntos
Hidrogéis , Proteínas de Ervilha , Hidrogéis/química , Fibras na Dieta , Riboflavina , Polímeros/química
7.
Food Chem ; 318: 126520, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32155563

RESUMO

Gas chromatography-ion mobility spectrometry (GC-IMS) and dynamic quantitative descriptive analysis (D-QDA) were combined to explore the aroma release and perception from the retronasal cavity during bread consumption. D-QDA results elucidated that the sweet, creamy, and roasty notes were the most active attributes during oral processing. The final stage of oral processing had the most complicated changing pattern, followed by the intermediate and initial stages. Thirteen aroma compounds were detected in the retronasal cavity, of which eight had odor activity values (OAVs) greater than 1. The total OAV changing pattern was consistent with the D-QDA results. Addition experiments further confirmed that acetoin, 2,3-butanedione, and 3-(methylthio)propanal were key aroma compounds contributing to retronasal olfaction. 2,3-Butanedione and 3-(methylthio)propanal were both identified as key odorants in the mouth cavity and retronasal cavity during oral processing, but they had 30% loss during the breath delivery from the mouth cavity to the retronasal cavity.


Assuntos
Pão/análise , Odorantes/análise , Acetoína/análise , Adulto , Diacetil/análise , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Masculino , Cavidade Nasal , Reprodutibilidade dos Testes , Olfato , Paladar , Triticum , Compostos Orgânicos Voláteis/análise
8.
Aliment Pharmacol Ther ; 51(4): 469-478, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31943297

RESUMO

BACKGROUND: To date, 14 single-nucleotide polymorphisms (SNPs) have been identified as susceptibility loci for chronic hepatitis B (CHB). AIM: To investigate if these SNPs are associated with treatment response of hepatitis B e antigen (HBeAg)-positive CHB patients. METHODS: We performed a retrospective analysis of 1623 Han Chinese HBeAg-positive CHB patients (782 patients treated with pegylated interferon alpha [PegIFNα] for 48 weeks plus 24 weeks follow-up, and 841 patients treated with nucleos(t)ide analogues [NUCs] for 104 weeks) included in four phase-IV multicentre randomised controlled trials. All 14 SNPs were genotyped for each CHB patient. A polygenic score (PGS) was used to evaluate the cumulative effect of multiple SNPs. The associations of SNPs or PGS with combined response (CR) and hepatitis B s antigen (HBsAg) loss were assessed. RESULTS: We found that rs12614, a missense variant of complement factor B (CFB), was significantly associated with CR in PegIFNα-treated patients, and the CR rate in patients with the rs12614 TT/CT genotype was less than one-third of that in patients with the CC genotype (7.4% vs 22.6%, P = 0.009). Moreover, a PGS integrating CFB rs12614 and STAT4 rs7574865 (previously reported to be associated with response to PegIFNα) was significantly associated with both CR (P-trend = 4.000 × 10-4 ) and HBsAg loss (P-trend = 0.010) in PegIFNα-treated patients. However, none of the SNPs were associated with treatment response in NUCs-treated patients. CONCLUSIONS: CFB rs12614 is an independent predictor of response to PegIFNα therapy in Chinese HBeAg-positive CHB patients. A PGS integrating CFB rs12614 with STAT4 rs7574865 can effectively discriminate responders to PegIFNα from nonresponders.


Assuntos
Antivirais/uso terapêutico , Biomarcadores Farmacológicos , Fator B do Complemento/genética , Hepatite B Crônica , Interferon-alfa/uso terapêutico , Mutação de Sentido Incorreto , Adolescente , Adulto , Idoso , Povo Asiático/estatística & dados numéricos , Biomarcadores Farmacológicos/análise , Estudos de Coortes , Esquema de Medicação , Feminino , Genótipo , Antígenos E da Hepatite B/imunologia , Hepatite B Crônica/diagnóstico , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/genética , Hepatite B Crônica/imunologia , Humanos , Interferon-alfa/química , Masculino , Pessoa de Meia-Idade , Polietilenoglicóis/química , Polietilenoglicóis/uso terapêutico , Polimorfismo de Nucleotídeo Único , Prognóstico , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
9.
Food Res Int ; 123: 612-622, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31285010

RESUMO

The purpose of this study was to investigate the aroma release and perception from white bread during oral processing by gas chromatography-ion mobility spectrometry (GC-IMS) and dynamic sensory evaluation of temporal dominance of sensations (TDS). TDS curves indicated that two maximum aroma perception signals, fermentation-like and flour-like attributes, were perceived at the beginning and swallowing, respectively. The fermentation-like, flour-like, and sour attributes were the 3 dominant aromas during oral processing. A total of 35 volatile compounds were detected in the mouth cavity during chewing white bread, 19 of them were confirmed and quantified by using the respective external standard. Based on PLSR analysis, 8 aroma compounds were predicted as potent odorants contributing to the aroma perception from chewing white bread. By application of odor activity values analysis and addition experiments, ethyl butanoate, butyl acetate, hexanal, 3-(methylthio)-propanal, 3-methylbutanal, and 2,3-butanedione were confirmed as the key odorants contributing to the aroma perception during chewing of white bread.


Assuntos
Pão/análise , Cromatografia Gasosa-Espectrometria de Massas , Mastigação , Odorantes/análise , Paladar , Acetatos/análise , Adulto , Aldeídos/análise , Butileno Glicóis/análise , Comportamento do Consumidor , Feminino , Fermentação , Farinha/análise , Humanos , Espectrometria de Mobilidade Iônica , Masculino , Pirazinas/análise , Triticum/química , Compostos Orgânicos Voláteis/análise , Adulto Jovem
10.
Food Chem ; 298: 125003, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260957

RESUMO

The oral breakdown, sensory properties, and volatile release during mastication of white bread were investigated. The results of correlation analysis for white bread's physical properties and it's oral physiological parameters during chewing have elucidated that bread's physical properties determined the oral processing behavior. During chewing of white bread, 15 dominant ions with regularly changing patterns were monitored by proton transfer reaction-mass spectrometry (PTR-MS). These dominant ions derived from 32 volatile compounds were further confirmed by pure standards. Partial least squares regression (PLSR) analysis was used to explore the positive correlations between the sensory analysis and the dominant aroma compounds. Results have shown that 9 aroma compounds were predicted as the potent odorants contributing to the changes in aroma profiles. Finally, 3-hydroxy-2-butanone, 2-methyl-1-propanol, and heptanoic acid were confirmed as the key aroma compounds contributing to the changes in aroma profiles of white bread before and after chewing.


Assuntos
Pão , Mastigação , Odorantes/análise , Compostos Orgânicos Voláteis/análise , Acetoína/análise , Adulto , Pão/análise , Butanóis/análise , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Cromatografia Gasosa-Espectrometria de Massas/estatística & dados numéricos , Ácidos Heptanoicos/análise , Humanos , Análise dos Mínimos Quadrados , Masculino , Espectrometria de Massas/métodos , Espectrometria de Massas/estatística & dados numéricos , Saliva/química , Microextração em Fase Sólida/métodos , Paladar , Triticum/química
11.
Eur J Pharm Sci ; 35(1-2): 96-103, 2008 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-18644439

RESUMO

There are a number of therapies available to recanalize occluded arteries. However, even though proven beneficial, these approaches are not without significant shortcomings. Previous research showed that by encapsulating therapeutic thrombolytic enzymes in liposomic formulations, the reperfusion times in vivo were significantly lower than for administration of free thrombolytic. Like liposomes, biodegradable, diblock polymers of poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) have been shown to have therapeutic benefit as delivery vehicles for a variety of drug delivery concepts. We report on new formulations based on tissue plasminogen activator (tPA) encapsulated in magnetic, PLA-PEG microcarriers. We studied the tPA encapsulation efficiency, loading, and release after varying the molecular weight of polymer, carrier size, tPA solution composition, and use of ultrasound to enhance release. We loaded 3.3-9.4wt% tPA and 12-17wt% magnetite into the carriers, depending on the exact formulation. The release of tPA was complete 20min after reconstitution. Ultrasound insonation failed to enhance tPA release rates in smaller carriers but significantly enhanced release in larger carriers. With these formulations, we should be able to achieve lytic concentrations if we can magnetically concentrate 5mg of carrier within about 11ml of blood volume near the clot.


Assuntos
Ativador de Plasminogênio Tecidual/administração & dosagem , Implantes Absorvíveis , Fenômenos Químicos , Físico-Química , Portadores de Fármacos , Composição de Medicamentos , Excipientes , Óxido Ferroso-Férrico , Cinética , Magnetismo , Microscopia Eletrônica de Varredura , Microesferas , Polietilenoglicóis , Poliglactina 910 , Solubilidade , Ativador de Plasminogênio Tecidual/química
12.
Med Eng Phys ; 30(1): 1-8, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17400018

RESUMO

High gradient magnetic separation (HGMS) of magnetic materials from fluids or waste products has many established industrial applications. However, there is currently no technology employing HGMS for ex-vivo biomedical applications, such as for the removal of magnetic drug- or toxin-loaded spheres from the human blood stream. Importantly, human HGMS applications require special design modifications as, in contrast to conventional use where magnetic elements are permanently imbedded within the separation chambers, medical separators need to avoid direct contact between the magnetic materials and blood to reduce the risk of blood clotting and to facilitate convenient and safe treatment access for many individuals. We describe and investigate the performance of a magnetic separator prototype designed for biomedical applications. First, the capture efficiency of a prototype HGMS separator unit consisting of a short tubing segment and two opposing magnetizable fine wires along the outside of the tubing was investigated using 2D mathematical modeling. Second, the first-pass effectiveness to remove commercially available, magnetic polystyrene spheres from human blood using a single separator unit was experimentally verified. The theoretical and experimental data correlated well at low flow velocities (<5.0 cm/s) and high external magnetic fields (>0.05 T). This prototype separator unit removed >90% in a single pass of the magnetic spheres from water at mean flow velocity < or =8.0 cm/s and from blood mimic fluids (ethylene glycol-water solutions) at mean flow velocity < or =2.0 cm/s. In summary, we describe and prove the feasibility of a HGMS separator for biomedical applications.


Assuntos
Desenho Assistido por Computador , Separação Imunomagnética/instrumentação , Sangue , Simulação por Computador , Campos Eletromagnéticos , Desenho de Equipamento , Análise de Falha de Equipamento , Etilenoglicol/química , Humanos , Separação Imunomagnética/métodos , Técnicas Analíticas Microfluídicas/instrumentação , Microesferas , Poliestirenos/química , Soluções/química , Suspensões/química , Viscosidade
13.
Phys Med Biol ; 52(17): 5205-18, 2007 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-17762081

RESUMO

A portable separator has been developed to quantitatively separate blood-borne magnetic spheres in potentially high-flow regimes for the human detoxification purpose. In the separator design, an array of biocompatible capillary tubing and magnetizable wires is immersed in an external magnetic field that is generated by two permanent magnets. The wires are magnetized and the high magnetic field gradient from the magnetized wires helps to collect blood-borne magnetic nano/micro-spheres from the blood flow. In this study, a 3D numerical model was created and the effect of tubing-wire configurations on the capture efficiency of the system was analyzed using COMSOL Multiphysics 3.3(R). The results showed that the configuration characterized by bi-directionally alternating wires and tubes was the best design with respect to the four starting configurations. Preliminary in vitro experiments verified the numerical predictions. The results helped us to optimize a prototype portable magnetic separator that is suitable for rapid sequestration of magnetic nano/micro-spheres from the human blood stream while accommodating necessary clinical boundary conditions.


Assuntos
Materiais Biocompatíveis/isolamento & purificação , Análise Química do Sangue , Misturas Complexas/isolamento & purificação , Desenho Assistido por Computador , Hemofiltração/instrumentação , Magnetismo/instrumentação , Modelos Teóricos , Simulação por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Hemofiltração/métodos , Magnetismo/uso terapêutico , Miniaturização , Tamanho da Partícula
14.
Med Hypotheses ; 68(5): 1071-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17123743

RESUMO

We describe the conceptual approach, theoretical background and preliminary experimental data of a proposed platform technology for specific and rapid decorporation of blood-borne toxins from humans. The technology is designed for future emergent in-field or in-hospital detoxification of large numbers of biohazard-exposed victims; for example, after radiological attacks. The proposed systems is based on nanoscale technology employing biocompatible, superparamagnetic nanospheres, which are functionalized with target-specific antitoxin receptors, and freely circulate within the human blood stream after simple intravenous injection. Sequestration of the blood-borne toxins onto the nanosphere receptors generates circulating nanosphere-toxin complexes within a short time interval; mathematical modeling indicates prevailing of unbound nanosphere receptors over target toxin concentrations at most therapeutic injection dosages. After a toxin-specific time interval nanosphere-toxin complexes are generated within the blood stream and, after simple arterial or venous access, the blood is subsequently circulated via a small catheter through a portable high gradient magnetic separator device. In this device, the magnetic toxin complexes are retained by a high gradient magnetic field and the detoxified blood is then returned back to the blood circulation (extracorporeal circulation). Our preliminary in vitro experiments demonstrate >95% first pass capture efficiency of magnetic spheres within a prototype high gradient magnetic separation device. Further, based on the synthesis of novel hydrophobic magnetite nanophases with high magnetization ( approximately 55 emu/g), the first biodegradable magnetic nanospheres at a size range of approximately 280 nm and functionalized with PEG-maleimide surface groups for specific antibody attachment are described here. In future applications, we envision this technology to be suitable for emergent, in-field usage for acutely biohazard exposed victims as both the injectable toxin-binding magnetic spheres and the separator device are made to be portable, light-weight, zero-power, and self- or helper-employed. Details of the technology are presented and the state-of-knowledge and research is discussed.


Assuntos
Engenharia Biomédica/métodos , Separação Imunomagnética/instrumentação , Magnetismo , Modelos Biológicos , Nanotubos/toxicidade , Materiais Biocompatíveis/química , Biotinilação , Radioisótopos de Césio , Filtração , Humanos , Separação Imunomagnética/métodos , Injeções Intravenosas , Ácido Láctico/sangue , Ácido Láctico/química , Microesferas , Nanotecnologia/instrumentação , Nanotecnologia/métodos , Nanotubos/química , Tamanho da Partícula , Polietilenoglicóis/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Polímeros/química , Propriedades de Superfície
15.
J Control Release ; 119(1): 52-8, 2007 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-17350131

RESUMO

The objective of this study was to develop high magnetization, biodegradable/biocompatible polymer-coated magnetic nanospheres for biomedical applications. Magnetic spheres were prepared by a modified single oil-in-water emulsion-solvent evaporation method utilizing highly-concentrated hydrophobic magnetite and poly(d,l lactide-co-glycolide) (PLGA). Hydrophobic magnetite prepared using oleic acid exhibited high magnetite concentrations (84 wt.%) and good miscibility with biopolymer solvents to form a stable oily suspension. The oily suspension was then emulsified within an aqueous solution containing poly(vinyl alcohol). After rapid evaporation of the organic solvent, we obtained solid magnetic nanospheres. We characterized these spheres in terms of external morphology, microstructure, size and zeta potential, magnetite content and distribution within the nanospheres, and magnetic properties. The results showed good encapsulation where the magnetite distorted the smooth surface morphology only at the highest magnetite concentrations. The mean diameter was 360-370 nm with polydispersity indices of 0.12-0.20. We obtained high magnetite content (40-60%) and high magnetization (26-40 emu/g). The high magnetization properties were obtained while leaving sufficient polymer to retain drugs making these biodegradable spheres suitable as a potential platform for the design of magnetically-guided drug delivery and other in vivo biomagnetic applications.


Assuntos
Ácido Láctico/síntese química , Magnetismo , Nanotubos/química , Ácido Poliglicólico/síntese química , Polímeros/síntese química , Disponibilidade Biológica , Ácido Láctico/farmacocinética , Ácido Poliglicólico/farmacocinética , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Polímeros/farmacocinética
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