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1.
Molecules ; 28(4)2023 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-36838949

RESUMO

In this paper, an effective method for preparing poly (p-phenylene terephthalamide) -co- poly (dodecanedioyl) decylamine (PA10T/1012)/graphene oxide (GO) composites by pre-dispersion and one-step in situ polymerization was proposed for the first time. During the process of polycondensation, the condensation between the terminal amino groups of PA10T/1012 chains and the oxygen-containing functional groups of GO allowed nylon to be grafted onto graphene sheets. The effects of polymer grafting on the thermal and mechanical properties of (PA10T/1012)/GO composites were studied in detail. Due to the interaction between PA10T/1012 grafted graphene sheets and its matrix, GO is well dispersed in the PA10T/1012 matrix and physically entangled with it, forming a cross-linked network structure of polymer bridged graphene, thus obtaining enhanced tensile strength, tensile modulus and impact strength. More importantly, benefiting from the cross-linked network structure, the heat distortion temperature (HDT) of the composite is greatly increased from 77.3 °C to 144.2 °C. This in situ polycondensation method opens a new avenue to prepare polycondensate graphene-based composites with high strength and high heat distortion temperatures.


Assuntos
Grafite , Nylons , Temperatura , Polimerização , Grafite/química , Temperatura Alta , Polímeros/química
2.
Matern Child Health J ; 22(12): 1771-1779, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30006730

RESUMO

Objective To examine changes in the prevalence and odds of unmet healthcare needs and healthcare utilization among low-income women of reproductive age (WRA) after Ohio's 2014, ACA-associated Medicaid expansion, which extended coverage to non-senior adults with a family income ≤ 138% of the federal poverty level. Methods We analyzed publically available data from the 2012 and 2015 Ohio Medicaid Assessment Survey (OMAS), a cross-sectional telephone survey of Ohio's non-institutionalized adult population. The study included 489 low-income women in 2012 and 1273 in 2015 aged 19-44 years who were newly eligible for Medicaid after expansion in January 2014. Four unmet healthcare need and three healthcare utilization measures were examined. We fit survey-weighted logistic regression models adjusted for race/ethnicity, working status, and educational attainment to determine whether the odds of each measure differed between 2012 and 2015. Results In 2015, low-income WRA had a significantly lower odds of reporting an unmet dental care need (ORadj = 0.72, 95% CI 0.54, 0.95), unmet vision care need (ORadj = 0.68, 95% CI 0.50, 0.93), unmet mental health need (ORadj = 0.57, 95% CI 0.39, 0.83), and unmet prescription need (ORadj = 0.39, 95% CI 0.45, 0.80) compared to 2012. There were no significant differences in the odds of seeing a doctor or dentist in the past year or of having a usual source of care for low-income WRA in 2012 and 2015. Conclusions for Practice After Ohio's 2014 Medicaid expansion the odds of low-income WRA having unmet healthcare needs was reduced. Future research should examine outcomes after a longer period of follow-up and include additional measures, such as self-rated health status.


Assuntos
Acessibilidade aos Serviços de Saúde , Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Medicaid , Pessoas sem Cobertura de Seguro de Saúde , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Pobreza , Adulto , Estudos Transversais , Feminino , Humanos , Renda , Masculino , Pessoas sem Cobertura de Seguro de Saúde/estatística & dados numéricos , Ohio , Patient Protection and Affordable Care Act , Estados Unidos
3.
J Immunol ; 193(5): 2087-95, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25070847

RESUMO

Naive T cell activation is normally restricted to the lymphoid organs, in part because of their limited ability to migrate into the parenchyma of peripheral tissues. The liver vasculature is unique, however, and circulating leukocytes within the hepatic sinusoids have direct access to liver-resident cells, which include an abundant population of Kupffer cells. It is well accepted that recognition of cognate Ag within the liver leads to naive CD8(+) T cell activation in situ, but it is unclear whether the liver also supports naive CD4(+) T cell activation. In this study, we show that naive CD4(+) T cells can be activated to proliferate in the liver when cognate Ag expression is induced in hepatocytes by recombinant adeno-associated viral vectors. Ag-specific retention and activation of naive CD4(+) T cells within the liver are independent of lymphoid tissues but dependent on a clodronate liposome-sensitive population of liver-resident phagocytic cells. To our knowledge, this study provides the first unequivocal evidence that naive CD4(+) T cells can be activated in a nonlymphoid organ. It also gives critical insight into how CD4(+) T cells specific for Ag expressed in the liver are recruited to participate in protective or pathological responses during hepatotropic infections and autoimmune liver disease.


Assuntos
Doenças Autoimunes/imunologia , Linfócitos T CD4-Positivos/imunologia , Células de Kupffer/imunologia , Hepatopatias/imunologia , Fígado/imunologia , Animais , Doenças Autoimunes/genética , Doenças Autoimunes/patologia , Conservadores da Densidade Óssea/farmacologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Ácido Clodrônico/farmacologia , Células de Kupffer/patologia , Lipossomos , Fígado/patologia , Hepatopatias/genética , Hepatopatias/patologia , Ativação Linfocitária , Camundongos , Camundongos Transgênicos
4.
Prev Med ; 74: 55-8, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25773470

RESUMO

OBJECTIVE: Regular use of recommended preventive health services can promote good health and prevent disease. However, individuals may forgo obtaining preventive care when they are busy with competing activities and commitments. This study examined whether time pressure related to work obligations creates barriers to obtaining needed preventive health services. METHODS: Data from the 2002-2010 Medical Expenditure Panel Survey (MEPS) were used to measure the work hours of 61,034 employees (including 27,910 females) and their use of five preventive health services (flu vaccinations, routine check-ups, dental check-ups, mammograms and Pap smear). Multivariable logistic regression analyses were performed to test the association between working hours and use of each of those five services. RESULTS: Individuals working long hours (>60 per week) were significantly less likely to obtain dental check-ups (OR=0.81, 95% CI: 0.72-0.91) and mammograms (OR=0.47, 95% CI: 0.31-0.73). Working 51-60 h weekly was associated with less likelihood of receiving Pap smear (OR=0.67, 95% CI: 0.46-0.96). No association was found for flu vaccination. CONCLUSIONS: Time pressure from work might create barriers for people to receive particular preventive health services, such as breast cancer screening, cervical cancer screening and dental check-ups. Health practitioners should be aware of this particular source of barriers to care.


Assuntos
Emprego/estatística & dados numéricos , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Seguro Saúde/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Serviços Preventivos de Saúde/estatística & dados numéricos , Adolescente , Adulto , Serviços de Saúde Bucal/estatística & dados numéricos , Detecção Precoce de Câncer/estatística & dados numéricos , Emprego/organização & administração , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Vacinas contra Influenza/administração & dosagem , Cobertura do Seguro/legislação & jurisprudência , Cobertura do Seguro/estatística & dados numéricos , Seguro Saúde/legislação & jurisprudência , Modelos Logísticos , Masculino , Mamografia/estatística & dados numéricos , Pessoa de Meia-Idade , Teste de Papanicolaou/estatística & dados numéricos , Patient Protection and Affordable Care Act/normas , Admissão e Escalonamento de Pessoal , Fatores de Tempo , Estados Unidos , Adulto Jovem
5.
Small ; 10(21): 4332-9, 2014 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-25044955

RESUMO

Nanopore technology is one of the most promising approaches for fast and low-cost DNA sequencing application. Single-stranded DNA detection is primary objective in such device, while solid-state nanopores remain less explored than their biological counterparts due to bio-molecule clogging issue caused by surface interaction between DNA and nanopore wall. By surface coating a layer of polyethylene glycol (PEG), solid-state nanopore can achieve long lifetime for single-stranded DNA sticky-free translocation at pH 11.5. Associated with elimination of non-specific binding of molecule, PEG coated nanopore presents new surface characteristic as less hydrophility, lower 1/f noise, and passivated surface charge responsiveness on pH. Meanwhile, conductance blockage of single-stranded DNA is found to be deeper than double-stranded DNA, which can be well described by a string of blobs model for a quasi-equilibrium state polymer in constraint space.


Assuntos
Materiais Revestidos Biocompatíveis/síntese química , DNA de Cadeia Simples/análise , DNA de Cadeia Simples/química , Nanoporos , Polietilenoglicóis/química , Análise de Sequência de DNA/instrumentação , Adesividade/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , DNA de Cadeia Simples/efeitos dos fármacos , Análise em Microsséries/instrumentação , Análise em Microsséries/métodos , Movimento/efeitos dos fármacos , Nanotecnologia/instrumentação , Nanotecnologia/métodos , Análise de Sequência de DNA/métodos , Propriedades de Superfície
6.
Nano Lett ; 13(7): 3048-52, 2013 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-23802688

RESUMO

Voltage-biased solid-state nanopores are well established in their ability to detect and characterize single polymers, such as DNA, in electrolytes. The addition of a pressure gradient across the nanopore yields a second molecular driving force that provides new freedom for studying molecules in nanopores. In this work, we show that opposing pressure and voltage bias enables nanopores to detect and resolve very short DNA molecules, as well as to detect near-neutral polymers.


Assuntos
DNA/química , DNA/efeitos da radiação , Membranas Artificiais , Nanoporos/ultraestrutura , Biopolímeros/química , Biopolímeros/efeitos da radiação , DNA/ultraestrutura , Campos Eletromagnéticos , Eletroporação/métodos , Teste de Materiais , Modelos Químicos , Modelos Moleculares , Movimento (Física) , Tamanho da Partícula , Pressão
7.
Prev Med Rep ; 31: 102106, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36820365

RESUMO

Smokers are more likely to be low-income with limited access to health services. Although Medicaid expansion under the Patient Protection and Affordable Care Act improved access to care for low-income adults, long-term trends in health care access among low-income smokers remain uncharacterized. The study evaluated changes in five access measures among low-income nonelderly (19-64) adults (N = 28976) across smoking status using pooled data from a statewide survey in Ohio covering pre- (i.e., 2012) and post-Medicaid expansion periods (2015, 2017, and 2019) guided by a comprehensive framework of health care access. We found improvements in some, but not all, health care access measures among low-income smokers in the post-Medicaid-expansion period compared to the pre-expansion period. Compared to 2012, the odds for unmet dental care needs declined in 2015 (aOR = 0.67, 95 % CI = 0.45-1.01), 2017 (aOR = 0.53, 95 % CI = 0.35-0.81), and 2019 (aOR = 0.65, 95 % CI = 0.40-1.05) (p trend < 0.001). Similarly, the odds for unmet other health care needs (i.e., medical exams and supplies) were lower in 2015 (aOR = 0.64, 95 % CI = 0.39-1.06), 2017 (aOR = 0.56, 95 % CI = 0.34-0.93), and 2019 (aOR = 0.47, 95 % CI = 0.27-0.83) (p trend < 0.001). Difficulty paying medical bills was also significantly lower in 2015 (aOR = 0.62, 95 % CI = 0.43-0.89), 2017 (aOR = 0.57, 95 % CI = 0.39-0.83) and 2019 (aOR = 0.57, 95 % CI = 0.37-0.87) (p trend < 0.001). While there was notable progress in measures of affordability (i.e., paying medical bills) as well as care availability and accommodation (i.e., unmet needs), there were no meaningful changes in the approachability of care (i.e., having a usual source of care).

8.
Biomed Microdevices ; 14(4): 659-67, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22391881

RESUMO

In this work, a mesh-supported submicron parylene-C membrane (MSPM) is proposed as an artificial Bruch's membrane for the therapy of age-related macular degeneration (AMD). Any artificial Bruch's membrane must first satisfy two important requirements. First, it should be as permeable as healthy human Bruch's membrane to support nutrients transportation. Secondly, it should be able to support the adherence and proliferation of retinal pigment epithelial (RPE) cells with in vivo-like morphologies and functions. Although parylene-C is widely used as a barrier layer in many biomedical applications, it is found that parylene-C membranes with submicron thickness are semipermeable to macromolecules. We first measure the permeability of submicron parylene-C and find that 0.15-0.30 µm parylene-C has similar permeability to healthy human Bruch's membranes. Blind-well perfusion cell viability experiments further demonstrate that nutrients and macromolecules can diffuse across 0.30 µm parylene-C to nourish the cells. A mesh-supported submicron parylene-C membrane (MSPM) structure is design to enhance the mechanical strength of the substrate. In vitro cells culture on the MSPM (with 0.30 µm ultrathin parylene-C) shows that H9-RPE cells are able to adhere, proliferate, form epithelial monolayer with tight intracellular junctions, and become well-polarized with microvilli, which exhibit similar characteristics to RPE cells in vivo. These studies have demonstrated the potential of the MSPM as an artificial Bruch's membrane for RPE cell transplantation.


Assuntos
Técnicas de Cultura de Células/instrumentação , Membranas Artificiais , Polímeros/química , Epitélio Pigmentado da Retina/citologia , Xilenos/química , Linhagem Celular , Proliferação de Células , Sobrevivência Celular , Difusão , Desenho de Equipamento , Humanos , Fenômenos Mecânicos , Peso Molecular , Permeabilidade
9.
Ophthalmic Res ; 48(4): 186-91, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22868580

RESUMO

OBJECTIVE: To evaluate the feasibility of a new technique for the implantation of ultrathin substrates containing stem cell-derived retinal pigment epithelium (RPE) cells into the subretinal space of retina-degenerate Royal College of Surgeon (RCS) rats. METHODS: A platform device was used for the implantation of 4-µm-thick parylene substrates containing a monolayer of human embryonic stem cell-derived RPE (hESC-RPE). Normal Copenhagen rats (n = 6) and RCS rats (n = 5) were used for the study. Spectral-domain optical coherence tomography (SD-OCT) scanning and histological examinations were performed to confirm placement location of the implant. hESC-RPE cells attached to the substrate before and after implantation were evaluated using standard cell counting techniques. RESULTS: SD-OCT scanning and histological examination revealed that the substrates were precisely placed in the rat's subretinal space. The hESC-RPE cell monolayer that covered the surface of the substrate was found to be intact after implantation. Cell counting data showed that less than 2% of cells were lost from the substrate due to the implantation procedure (preimplantation count 2,792 ± 74.09 cells versus postimplantation count 2,741 ± 62.08 cells). Detailed microscopic examination suggested that the cell loss occurred mostly along the edges of the implant. CONCLUSION: With the help of this platform device, it is possible to implant ultrathin substrates containing an RPE monolayer into the rat's subretinal space. This technique can be a useful approach for stem cell-based tissue bioengineering techniques in retinal transplantation research.


Assuntos
Células-Tronco Embrionárias/citologia , Polímeros , Distrofias Retinianas/terapia , Epitélio Pigmentado da Retina/transplante , Transplante de Células-Tronco , Engenharia Tecidual , Alicerces Teciduais , Xilenos , Animais , Contagem de Células , Estudos de Viabilidade , Humanos , Ratos , Ratos Mutantes , Retina/patologia , Distrofias Retinianas/diagnóstico , Tomografia de Coerência Óptica
10.
Carbohydr Polym ; 275: 118740, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34742443

RESUMO

Cellulose has attracted an increasing attention for piezoelectric energy harvesting. However, the limited piezoelectricity of natural cellulose constraints the applications. Therefore, we demonstrate the development of piezoelectric nanogenerators based on robust, durable layered membranes composed of cotton cellulose interfaced maleic-anhydride-grafted polyvinylidene fluoride (PVDF-g-MA) nanofibers. Exploiting polydopamine@BaTiO3 (pBT) nanoparticles as interlayer bridges, interlocked layer-layer interfaces that covalently bind component layers are constructed by a facile and scalable approach. As-obtained membranes exhibit significantly improved piezoelectricity with a maximum piezoelectric coefficient of 27.2 pC/N, power density of 1.72 µW/cm2, and stability over 8000 cycles. Substantial enhancement in piezoelectricity over pristine cellulose is ascribed to the synergy of components and the localized stress concentration induced by pBT nanoparticles. The self-powered device could also be used to detect human physiological motions in different forms. Such cellulose-based membranes can be up-scaled to fabricate ecofriendly, flexible and durable energy harvesters and self-powered wearable sensors.


Assuntos
Materiais Biocompatíveis/química , Celulose/química , Fontes de Energia Elétrica , Nanofibras/química , Fibra de Algodão , Estrutura Molecular , Tamanho da Partícula
11.
Ann Palliat Med ; 10(12): 12664-12677, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35016469

RESUMO

BACKGROUND: With the continuous improvement of human living standards, more and more dental patients are requiring oral implant restoration treatment. However, there is still controversy regarding the influence of risk factors such as osteoporosis, radiotherapy, diabetes, and smoking on the failure of oral implants. This study aimed to explore the correlation between risk factors and failure of oral implant restoration treatment. METHODS: The databases of China National Knowledge Infrastructure (CNKI), Baidu Academic, Weipu, Wanfang, PubMed, EBSCO, Medline, Web of knowledge, Ovid, and the Cochrane Library were searched. The search strategies included: subject terms related to research results such as survival, osseointegration, failure, removal, replacement, and loss; related to risk factors: osteoporosis, head and neck cancer, diabetes, and smoking; and oral implantology as a keyword. RESULTS: Thirty-two articles were included in meta-analysis, there was a high heterogeneity between radiotherapy and dental implant failure (I2=71.6%, P=0.000), and there was an obvious correlation between radiotherapy and dental implant failure [relative risk (RR) =2.09, 95% confidential interval (CI): 1.68-2.61]. There was heterogeneity between diabetes and oral implant failure in the included articles (I2=59.6%, P=0.084). There was no remarkable correlation between osteoporosis and dental implant failure (RR =1.19, 95% CI: 0.81-1.74). There was a high heterogeneity between smoking and dental implant failure in the included articles (I2=33.8%, P=0.092), showing obvious correlation (RR =1.80, 95% CI: 1.53-2.11). DISCUSSION: The results of meta-analysis confirmed that radiotherapy and smoking were greatly associated with oral implant failure.


Assuntos
Diabetes Mellitus , Osteoporose , Administração Oral , Humanos , Fatores de Risco , Fumar
12.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 39(5): 570-575, 2021 Oct 01.
Artigo em Inglês, Zh | MEDLINE | ID: mdl-34636206

RESUMO

OBJECTIVES: This study aims to evaluate the endo-sinus bone remodeling of dental implants placed via osteotome sinus floor elevation (OSFE) after 6 months and using different implant protrusion lengths and bone grafts through cone beam computed tomography (CBCT). METHODS: Ninety-six patients with 124 implants were included and assigned into four groups. Group 1: implant protrusion length<4 mm with bone graft; group 2: implant protrusion length>4 mm with bone graft; group 3: implant protrusion length<4 mm without bone graft; group 4: implant protrusion length>4 mm without bone graft. Apical bone gain (ABG), cortical bone gain (CBG), bone density gain (BDG), and marginal bone loss (MBL) were observed and analyzed at baseline and 6 months after implant surgery. RESULTS: The CBG in grafted groups 1 and 2 was higher than that in non-grafted groups. The ABG and BDG were higher in non-grafted groups 3 and 4 than in grafted groups, and the levels in group 3 were higher than those in group 4. The CBG in grafted group 2 was higher than that in group 1. No significant difference was observed in MBL analysis. CONCLUSIONS: The BDG of IPL<4 mm implants was higher than IPL>4 mm implant when bone grafts were not applied. No relevance was observed between IPL and CBG. Bone grafts can accelerate endo-sinus bone remodeling by increasing CBG and dissipating the influence of IPL on BDG.


Assuntos
Implantes Dentários , Levantamento do Assoalho do Seio Maxilar , Implantação Dentária Endóssea , Humanos , Maxila/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
13.
Mater Sci Eng C Mater Biol Appl ; 118: 111527, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33255080

RESUMO

A novel nanodrug delivery system (NDDS) based on block copolymers of Poly(DEA)-block-Poly(PgMA) (PDPP) was developed to enhance in vitro cellular uptake and anticancer efficacy. pH-responsive doxorubicin (DOX) based small molecule prodrug (DOX-hyd-N3) and mPEG-N3 were co-conjugated onto PDPP via copper-catalyzed "Click chemistry" to give a dual pH-responsive polymeric prodrug (mPEG-g-PDPP-g-hyd-DOX), which could be self-assembled into core-shell polymeric micelles (M(DOX)) with particles size of 81 ± 1 nm in aqueous phase. Additionally, the pH-responsive charge-reversal, stability and drug release behaviour at different pHs were then evaluated. Moreover, the surface charge of M(DOX) could quickly convert from negative (-6.64 ± 3.37 mV) to positive (5.35 ± 1.33 mV) thanks to the protonation of Poly(DEA) moieties as the pH value decreased from 7.4 during blood circulation to 6.5 in extracellular of tumour tissues. Meanwhile, according to the cytotoxicity determined by CCK-8 assay, cellular uptake, flow-cytometric and apoptosis profiles of two human cancer cell lines (HeLa and SW480), we could draw the conclusion that the cellular uptake and anticancer efficacy were significantly enhanced when cells were incubated with micelles at pH 6.5 due to the charge-reversal of micelles from negative to positive. With the protonation of Poly(DEA) moieties in acidic extracellular microenvironment and the pH-responsive DOX release with hydrazone linkage in endo/lysosome pH, this dual pH-responsive-charge-reversal micelle platform might become an encouraging strategy for more effective cancer treatment.


Assuntos
Doxorrubicina , Micelas , Doxorrubicina/farmacologia , Portadores de Fármacos , Liberação Controlada de Fármacos , Humanos , Concentração de Íons de Hidrogênio , Polímeros
14.
Lab Chip ; 10(14): 1826-34, 2010 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-20431822

RESUMO

Parylene-C has been widely used as a biocompatible material for microfluidics and micro total analysis system (microTAS) applications in recent decades. However, its autofluorescence can be a major obstacle for parylene-C based devices used in applications requiring sensitive fluorescence detection. In this paper, Parylene-C was compared with other commonly used polymer and plastic materials in microTAS devices for their autofluorescence. We also report here an in-depth study of the behaviors and mechanisms of the autofluorescence of parylene-C, as well as several other commercialized members in the parylene family, including parylene-D, parylene-N and parylene-HT, using epifluorescence microscopy, fluorimeter and infrared spectroscopy. Strong autofluorescence was induced in parylene-C during short-wavelength excitation (i.e. UV excitation). Variation of autofluorescence intensity of parylene-C film was found to be related to both dehydrogenation and photo-oxidation. Moreover, the influence of microfabrication process on parylene-C autofluorescence was also evaluated. Parylene-HT, which exhibits low initial autofluorescence, decreasing autofluorescence behavior under UV excitation and higher UV stability, can be a promising alternative for microTAS applications with fluorescence detection.


Assuntos
Materiais Biocompatíveis/química , Polímeros/química , Espectrometria de Fluorescência , Xilenos/química , Teste de Materiais
15.
Pharm Res ; 27(1): 187-99, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19888639

RESUMO

PURPOSE: To study the targeting and photodynamic therapy efficiency of porphyrin and galactosyl conjugated micelles based on amphiphilic copolymer galactosyl and mono-aminoporphyrin (APP) incoporated poly(2-aminoethyl methacrylate)-polycaprolactone (Gal-APP-PAEMA-PCL). METHODS: Poly(2-aminoethyl methacrylate)-polycaprolactone (PAEMA-PCL) was synthesized by the combination of ring opening polymerization and reversible addition-fragmentation chain transfer (RAFT) polymerization, and then Gal-APP-PAEMA-PCL was obtained after conjugation of lactobionic acid and 5-(4-aminophenyl)-10,15,20-triphenylporphyrin (APP) to PAEMA-PCL. The chemical structures of the copolymers were characterized, and their biological properties were evaluated in human laryngeal carcinoma (HEp2) and human hepatocellular liver carcinoma (HepG2) cells. RESULTS: Both APP-PAEMA-PCL and Gal-APP-PAEMA-PCL did not exhibit dark cytotoxicity to HEp2 cells and HepG2 cells. However, Gal-APP-PAEMA-PCL was taken up selectively by HepG2 cells and had the higher phototoxicity effect. Both polymers preferentially localized within cellular vesicles that correlated to the lysosomes. CONCLUSIONS: The results indicated that porphyrin and galactosyl conjugated polymer micelles exhibited higher targeting and photodynamic therapy efficacy in HepG2 cells than in HEp2 cells.


Assuntos
Portadores de Fármacos/síntese química , Sistemas de Liberação de Medicamentos/métodos , Galactose/química , Fotoquimioterapia/métodos , Polímeros/síntese química , Porfirinas/síntese química , Receptor de Asialoglicoproteína/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Composição de Medicamentos/métodos , Ensaios de Seleção de Medicamentos Antitumorais , Galactose/farmacocinética , Galactose/farmacologia , Células Hep G2 , Humanos , Micelas , Modelos Biológicos , Tamanho da Partícula , Poliésteres/química , Porfirinas/farmacocinética , Porfirinas/farmacologia
16.
Int J Biol Macromol ; 155: 903-910, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31730992

RESUMO

Although electrospinning of nanofibrous scaffolds benefit to wound healing have been developed at a fast pace, achieving nanofibrous scaffolds with high absorptivity by green electrospinning and crosslinking techniques is still a great challenge. Here, we developed a maleilated hyaluronate/methacrylated poly (vinyl alcohol) (MHA) (MaPVA) composite nanofibers by electrospinning from pure water solvent and followed by photopolymerization to form crosslinking nanofibers network. Electrospinnability of MHA/MaPVA blend systems were investigated and the results shows that the morphology and diameter of the nanofibers were mainly affected by MHA/MaPVA weight ratios by changing viscosity and conductivity of the blend solutions. The crystalline microstructure of the electrospun fibers was not well developed due to intermolecular hydrogen bonding interaction between the molecules of MHA and MaPVA. The photocrosslinking MHA/MaPVA nanofibrous mats can swell to form fibrous hydrogels with high water absorption, meanwhile it is cytocompatible and capable of promoting the cell attachment, which render it great potential for wound dressings.


Assuntos
Curativos Hidrocoloides , Materiais Biocompatíveis/química , Hidrogéis/química , Nanofibras/química , Cicatrização , Animais , Linhagem Celular , Fibroblastos , Ácido Hialurônico/química , Camundongos , Álcool de Polivinil/química
17.
Colloids Surf B Biointerfaces ; 183: 110427, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31408782

RESUMO

A nanocarrier system of methoxypolyethylene glycol amine (mPEG-NH2) functionalized polydopamine (PDA) coated hollow mesoporous silica nanoparticles (HMSNs-PDA-PEG) was developed with pH-responsive, which combined doxorubicin hydrochloride (DOX) and quercetin (QUR) to reverse multidrug resistance (MDR) and improved anticancer effects on taxol (TAX) and DOX double resistant human colorectal cancer cell line HCT-8 (HCT-8/TAX cells). Well-dispersed nanoparticles (HMSNs-PDA-PEG) were prepared with a dimension of around 170 nm. The surface morphology and chemical properties of HMSNs-PDA-PEG were also successfully characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) method, Fourier transform infrared spectroscopy (FT-IR) and dynamic light scattering (DLS). Drug release experiments results indicated that DOX and QUR (QD) loaded nanoparticles (HMSNs-PDA-PEG@QD) had similar release kinetic profiles of each drug, which all exhibited highly sensitive to pH value due to the surface PDA coating. Additionally, the HCT-8 cells or HCT-8/TAX cells were employed to assess the cellular uptake and cytotoxicity of various drug-free or drug-loaded HMSNs samples. Meanwhile, a series of biological evaluations demonstrated that the HMSNs-PDA-PEG@QD exhibited remarkable ability to overcome MDR compared with free DOX and HMSNs-PDA-PEG@DOX. Taken together, these results revealed that HMSNs-PDA-PEG@QD was suitable as a prospective and efficient drug delivery nanosystem for overcoming multidrug resistance.


Assuntos
Antineoplásicos/farmacologia , Portadores de Fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Indóis/química , Nanopartículas/química , Polímeros/química , Dióxido de Silício/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/farmacologia , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , Humanos , Concentração de Íons de Hidrogênio , Cinética , Nanopartículas/ultraestrutura , Paclitaxel/farmacologia , Polietilenoglicóis/química , Porosidade , Quercetina/farmacologia
18.
Biomacromolecules ; 9(10): 2594-600, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18698817

RESUMO

To develop chitosan-based efficient gene vectors, chitosans with different molecular weights were chemically modified with low molecular weight polyethylenimine. The molecular weight and composition of polyethylenimine grafted N-maleated chitosan (NMC-g-PEI) copolymers were characterized using gel permeation chromatography (GPC) and (1)H NMR, respectively. Agarose gel electrophoresis assay showed that NMC-g-PEI had good binding ability with DNA, and the particle size of the NMC-g-PEI/DNA complexes was 200-400 nm, as determined by a Zeta sizer. The nanosized complexes observed by scanning electron microscopy (SEM) exhibited a compact and spherical morphology. The NMC-g-PEI copolymers showed low cytotoxicity and good transfection activity, comparable to PEI (25 KDa) in both 293T and HeLa cell lines, except for NMC 50K-g-PEI. The results indicated that the molecular weight of NMC-g-PEI has an important effect on cytotoxicity and transfection activity, and low molecular weight NMC-g-PEI has a good potential as efficient nonviral gene vectors.


Assuntos
Quitosana/química , Técnicas de Transferência de Genes , Vetores Genéticos/química , Polietilenoimina/química , Soluções Tampão , Cromatografia/métodos , DNA/química , Eletroforese em Gel de Ágar , Células HeLa , Humanos , Técnicas In Vitro , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura/métodos , Peso Molecular , Ligação Proteica , Transfecção
19.
Phys Med Biol ; 53(8): 2051-67, 2008 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-18364554

RESUMO

The purpose of this study was to choose an appropriate head scatter source model for the fast and accurate independent planar dose calculation for intensity-modulated radiation therapy (IMRT) with MLC. The performance of three different head scatter source models regarding their ability to model head scatter and facilitate planar dose calculation was evaluated. A three-source model, a two-source model and a single-source model were compared in this study. In the planar dose calculation algorithm, in-air fluence distribution was derived from each of the head scatter source models while considering the combination of Jaw and MLC opening. Fluence perturbations due to tongue-and-groove effect, rounded leaf end and leaf transmission were taken into account explicitly. The dose distribution was calculated by convolving the in-air fluence distribution with an experimentally determined pencil-beam kernel. The results were compared with measurements using a diode array and passing rates with 2%/2 mm and 3%/3 mm criteria were reported. It was found that the two-source model achieved the best agreement on head scatter factor calculation. The three-source model and single-source model underestimated head scatter factors for certain symmetric rectangular fields and asymmetric fields, but similar good agreement could be achieved when monitor back scatter effect was incorporated explicitly. All the three source models resulted in comparable average passing rates (>97%) when the 3%/3 mm criterion was selected. The calculation with the single-source model and two-source model was slightly faster than the three-source model due to their simplicity.


Assuntos
Cabeça/anatomia & histologia , Radioterapia de Intensidade Modulada/instrumentação , Radioterapia de Intensidade Modulada/métodos , Algoritmos , Simulação por Computador , Desenho de Equipamento , Cabeça/efeitos da radiação , Humanos , Modelos Estatísticos , Modelos Teóricos , Método de Monte Carlo , Imagens de Fantasmas , Fótons , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Espalhamento de Radiação , Fatores de Tempo
20.
Zootaxa ; 4375(1): 136-142, 2018 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-29689785

RESUMO

The new Hexactinellid sponge Chaunoplectella megapora sp. nov. reported in this study was collected from the COMRA contract area, the western part of Clarion-Clipperton Fracture Zone (CCFZ) in the eastern Pacific Ocean at a depth of 5258 m. This sponge's extraordinary multiporous body with the presence of unique codonhexasters, sigmatocomes, toothed discohexasters and hemidiscohexasters, as well as stellate disocohexasters, characterizes it as a new species in the genus Chaunoplectella. This report presents the first record of family Leucopsacidae at this site in the eastern Pacific Ocean.


Assuntos
Poríferos , Animais , Oceano Pacífico
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