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1.
ACS Nano ; 16(12): 20430-20444, 2022 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-36382718

RESUMO

Photothermal therapy (PTT) is an effective treatment modality that is highly selective for tumor suppression and is a hopeful alternative to traditional cancer therapy. However, PTT-induced inflammatory responses may result in undesirable side effects including increased risks of tumor recurrence and metastasis. Here we developed multifunctional MnO nanoparticles as scavengers of proinflammatory molecules to alleviate the PTT-induced inflammatory response. The MnO nanoparticles improve the PTT therapy by (1) binding and scavenging proinflammatory molecules to inhibit the proinflammatory molecule-induced Toll-like receptors (TLR) activation and nuclear factor kappa B (NF-κB) signaling; (2) inhibiting activated macrophage-induced macrophage recruitment; and (3) inhibiting tumor cell migration and invasion. In vivo experimental results showed that further treatment with MnO nanoparticles after laser therapy not only inhibited the PTT-induced inflammatory response and primary tumor recurrence but also significantly reduced tumor metastasis due to the scavenging activity. These findings suggest that MnO nanoparticles hold the potential for mitigating the therapy-induced severe inflammatory response and inhibiting tumor recurrence and metastasis.


Assuntos
Neoplasias da Mama , Nanopartículas Multifuncionais , Nanopartículas , Feminino , Humanos , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Nanopartículas/química , Recidiva Local de Neoplasia , Fototerapia/métodos , Recidiva , Inflamação
2.
Nat Commun ; 13(1): 5925, 2022 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-36207325

RESUMO

Periodontitis is a common type of inflammatory bone loss and a risk factor for systemic diseases. The pathogenesis of periodontitis involves inflammatory dysregulation, which represents a target for new therapeutic strategies to treat periodontitis. After establishing the correlation of cell-free DNA (cfDNA) level with periodontitis in patient samples, we test the hypothesis that the cfDNA-scavenging approach will benefit periodontitis treatment. We create a nanoparticulate cfDNA scavenger specific for periodontitis by coating selenium-doped hydroxyapatite nanoparticles (SeHANs) with cationic polyamidoamine dendrimers (PAMAM-G3), namely G3@SeHANs, and compare the activities of G3@SeHANs with those of soluble PAMAM-G3 polymer. Both G3@SeHANs and PAMAM-G3 inhibit periodontitis-related proinflammation in vitro by scavenging cfDNA and alleviate inflammatory bone loss in a mouse model of ligature-induced periodontitis. G3@SeHANs also regulate the mononuclear phagocyte system in a periodontitis environment, promoting the M2 over the M1 macrophage phenotype. G3@SeHANs show greater therapeutic effects than PAMAM-G3 in reducing proinflammation and alveolar bone loss in vivo. Our findings demonstrate the importance of cfDNA in periodontitis and the potential for using hydroxyapatite-based nanoparticulate cfDNA scavengers to ameliorate periodontitis.


Assuntos
Ácidos Nucleicos Livres , Dendrímeros , Periodontite , Selênio , Animais , Ácidos Nucleicos Livres/genética , Dendrímeros/farmacologia , Hidroxiapatitas , Camundongos , Periodontite/tratamento farmacológico
3.
J Clin Med ; 10(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34362147

RESUMO

Hemolytic anemia (HA) renders erythropoietic stress on the bone marrow and has been linked to osteoporosis. In this nationwide retrospective cohort study, we examined this correlation by utilizing the Taiwan National Health Insurance Research Database (NHIRD). We identified two cohorts, matching population with and without HA in a 1:4 ratio. A total of 2242 HA patients and 8968 non-HA patients were enrolled. Patients with HA had a significantly higher cumulative incidence (log-rank test p = 0.0073), higher incidence density (5.11 vs. 3.76 per 1000 persons-years), and a 1.31-fold risk of developing osteoporosis than non-HA patients (aHR = 1.31, 95% C.I. 1.04-1.63, p = 0.01). After adjusting for age, sex, and comorbidities, patients with factors including female (aHR = 2.57, 95% C.I. 2.05-3.22, p < 0.001), age > 65 (aHR = 9.25, 95% C.I. 7.46-11.50, p < 0.001), diagnosis of cholelithiasis (aHR = 1.76, 95% C.I. 1.20-2.58, p = 0.003) and peptic ulcer disease (aHR = 1.87, 95% C.I. 1.52-2.29, p < 0.001) had significantly higher risk of osteoporosis. We propose that this correlation may be related to increased hematopoietic stress, increased consumption of nitric oxide (NO) by hemolysis, and the inhibitory effects of iron supplements on osteogenesis through the receptor activator of nuclear factor κB ligand (RANKL)/Osteoprotegerin pathway and the Runt-related transcription factor 2 (RUNX2) factor. Our findings suggest that patients with hemolytic anemia are at a higher risk of developing osteoporosis, and it would be in the patient's best interest for physicians to be aware of this potential complication and offer preventative measures.

4.
Sci Rep ; 11(1): 10496, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34006944

RESUMO

Since iron is essential for neurotransmitter synthesis, decreased iron stores might lead to reduced production of biogenic amines which phenomenon was shown in Fibromyalgia (FM) patients. The aims are to investigate the association of iron deficiency anemia (IDA) and FM and to find the effects of different interventions. We conducted a study using the Taiwan National Health Insurance Research Database. The IDA cohort consisted of 13,381 patients with newly diagnosed IDA between 2000 and 2008. Each patient with IDA was frequency-matched with one people without IDA, by sex, age and index year. The Cox proportional hazards regression analysis was conducted to estimate the association between IDA and FM risk. The event was the occurrence of FM. The overall incidence density rate of FM in the IDA cohort was higher than in the non-IDA cohort with a multivariable Cox proportional hazards model measured adjusted hazard ratio [HR], 1.19; 95% confidence interval [CI], 1.13-1.25). When using non-IDA group as reference, we compared with different therapies for IDA. The adjusted HRs of FM were 1.38 (95% CI = 1.30-1.47), 1.10 (95% CI = 1.03-1.16), 1.18 (95% CI = 0.98-1.43) and 0.73 (95% CI = 0.58-0.90) for IDA patient without therapy, iron supplement alone, blood transfusion alone and both iron supplement and blood transfusion respectively. Our results suggest IDA is associated with an increased risk of FM. All patients should have iron supplementation both to correct anemia and replenish body stores.


Assuntos
Anemia Ferropriva/complicações , Fibromialgia/complicações , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Taiwan
5.
Biomaterials ; 272: 120770, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33798957

RESUMO

Three-dimensional in vitro tumor models provide more physiologically relevant responses to drugs than 2D models, but the lack of proper evaluation indices and the laborious quantitation of tumor behavior in 3D have limited the use of 3D tumor models in large-scale preclinical drug screening. Here we propose two indices of 3D tumor invasiveness-the excess perimeter index (EPI) and the multiscale entropy index (MSEI)-and combine these indices with a new convolutional neural network-based algorithm for tumor spheroid boundary detection. This new algorithm for 3D tumor boundary detection and invasiveness analysis is more accurate than any other existing algorithms. We apply this spheroid monitoring and AI-based recognition technique ("SMART") to evaluating the invasiveness of tumor spheroids grown from tumor cell lines and from primary tumor cells in 3D culture.


Assuntos
Aprendizado Profundo , Esferoides Celulares , Linhagem Celular Tumoral , Sobrevivência Celular , Avaliação Pré-Clínica de Medicamentos
6.
Adv Mater ; 32(50): e2004385, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33164250

RESUMO

Chemotherapy causes off-target toxicity and is often ineffective against solid tumors. Targeted and on-demand release of chemotherapeutics remains a challenge. Here, cancer-cell-membrane-coated mesoporous organosilica nanoparticles (MONs) containing X-ray- and reactive oxygen species (ROS)-responsive diselenide bonds for controlled release of doxorubicin (DOX) at tumor sites are developed. DOX-loaded MONs coated with 4T1 breast cancer cell membranes (CM@MON@DOX) show greater accumulation at tumor sites and prolonged blood circulation time versus an uncoated control in mice bearing 4T1 orthotopic mammary tumors. Under low-dose X-ray radiation, the DOX-loaded MONs exhibit carrier degradation-controlled release via cleavage of diselenide bonds, resulting in DOX-mediated immunogenic cell death at the tumor site. Combination with a PD-L1 checkpoint blockade further enhances inhibition of tumor growth and metastasis with low systemic toxicity. Together, the findings show the promise of these biomimetic, radiation-responsive diselenide-bond-bridged MONs in chemo-immunotherapy.


Assuntos
Materiais Biomiméticos/química , Portadores de Fármacos/química , Imunoterapia/métodos , Nanopartículas/química , Selênio/química , Dióxido de Silício/química , Animais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Neoplasias da Mama/radioterapia , Linhagem Celular Tumoral , Doxorrubicina/química , Doxorrubicina/uso terapêutico , Humanos , Camundongos , Porosidade , Raios X
7.
Mol Pharm ; 17(3): 757-768, 2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-32011888

RESUMO

Salmon calcitonin (sCT) is a potent calcium-regulating peptide hormone and widely applied for the treatment of some bone diseases clinically. However, the therapeutic usefulness of sCT is hindered by the frequent injection required, owing to its short plasma half-life and therapeutic need for a high dose. Oral delivery is a popular modality of administration for patients because of its convenience to self-administration and high patient compliance, while orally administered sCT remains a great challenge currently due to the existence of multiple barriers in the gastrointestinal (GI) tract. Here, we introduced an orally targeted delivery system to increase the transport of sCT across the intestine through both the paracellular permeation route and the bile acid pathway. In this system, sCT-based glycol chitosan-taurocholic acid conjugate (GC-T)/dextran sulfate (DS) ternary nanocomplexes (NC-T) were produced by a flash nanocomplexation (FNC) process in a kinetically controlled mode. The optimized NC-T exhibited well-controlled properties with a uniform and sub-60 nm hydrodynamic diameter, high batch-to-batch reproducibility, good physical or chemical stability, as well as sustained drug release behaviors. The studies revealed that NC-T could effectively improve the intestinal uptake and permeability, owing to its surface functionalization with the taurocholic acid ligand. In the rat model, orally administered NC-T showed an obvious hypocalcemia effect and a relative oral bioavailability of 10.9%. An in vivo assay also demonstrated that NC-T induced no observable side effect after long-term oral administration. As a result, the orally targeted nanocomplex might be a promising candidate for improving the oral transport of therapeutic peptides.


Assuntos
Calcitonina/administração & dosagem , Hormônios e Agentes Reguladores de Cálcio/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Absorção Intestinal/efeitos dos fármacos , Nanocompostos/química , Administração Oral , Animais , Disponibilidade Biológica , Transporte Biológico , Células CACO-2/efeitos dos fármacos , Células CACO-2/metabolismo , Calcitonina/efeitos adversos , Calcitonina/sangue , Calcitonina/farmacocinética , Cálcio/sangue , Hormônios e Agentes Reguladores de Cálcio/efeitos adversos , Hormônios e Agentes Reguladores de Cálcio/sangue , Hormônios e Agentes Reguladores de Cálcio/farmacocinética , Quitosana/química , Sulfato de Dextrana/química , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Meia-Vida , Humanos , Hipocalcemia/induzido quimicamente , Injeções Subcutâneas , Masculino , Ratos , Ratos Sprague-Dawley , Ácido Taurocólico/química
8.
J Transl Med ; 17(1): 154, 2019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31088562

RESUMO

BACKGROUND: The onset of chronic fatigue syndrome (CFS) has been shown to be associated with several immunological conditions such as infections or atopy. The aim of this study was to clarify the risk of chronic fatigue syndrome following the diagnosis of psoriasis, an immune-related dermatological disease, by analyzing the National Health Insurance Research Database of Taiwan. METHOD: 2616 patients aged 20 years or older with newly diagnosed psoriasis during 2004-2008 and 10,464 participants without psoriasis were identified. Both groups were followed up until the diagnoses of CFS were made at the end of 2011. RESULTS: The relationship between psoriasis and the subsequent risk of CFS was estimated through Cox proportional hazards regression analysis, with the incidence density rates being 2.27 and 3.58 per 1000 person-years among the non-psoriasis and psoriasis populations, respectively (adjusted hazard ratio [HR] = 1.48, with 95% confidence interval [CI] 1.07-2.06). In the stratified analysis, the psoriasis group were consistently associated with a higher risk of CFS in male sex (HR = 2.05, 95% CI 1.31-3.20) and age group of ≥ 60 years old (HR = 2.32, 95% CI 1.33-4.06). In addition, we discovered that the significantly increased risk of CFS among psoriasis patients is attenuated after they receive phototherapy and/or immunomodulatory drugs. CONCLUSIONS: The data from this population-based retrospective cohort study revealed that psoriasis is associated with an elevated risk of subsequent CFS, which is differentiated by sex and age.


Assuntos
Síndrome de Fadiga Crônica/epidemiologia , Síndrome de Fadiga Crônica/etiologia , Psoríase/complicações , Adulto , Estudos de Coortes , Comorbidade , Intervalos de Confiança , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fatores de Risco , Índice de Gravidade de Doença , Taiwan/epidemiologia , Adulto Jovem
9.
Integr Biol (Camb) ; 9(12): 956-967, 2017 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-29168874

RESUMO

In vitro models of the neuromuscular junction (NMJ) are emerging as a valuable tool to study synaptogenesis, synaptic maintenance, and pathogenesis of neurodegenerative diseases. Many models have previously been developed using a variety of cell sources for skeletal muscle and motoneurons. These models can advanced by integrating beneficial features of the native developmental milieu of the NMJ. We created a functional in vitro model of NMJ by bioreactor cultivation of transdifferentiated myocytes and stem cell-derived motoneurons, in the presence of electrical stimulation. In conjunction with a coculture medium, electrical stimulation resulted in improved maturation and function of motoneurons and myocytes, as evidenced by mature cellular structures, increased expression of neuronal and muscular genes, clusterization of acetylcholine receptors (AChRs) in the vicinity of motoneurons, and the response to glutamate stimulation. To validate the model and demonstrate its utility for pharmacological testing, we documented the potency of drugs that affect key pathways during NMJ signal transduction: (i) acetylcholine (ACh) synthesis, (ii) ACh vesicular storage, (iii) ACh synaptic release, (iv) AChR activation, and (v) ACh inactivation in the synaptic cleft. The model properly responded to the drugs in a concentration-dependent manner. We thus propose that this in vitro model of NMJ could be used as a platform in pharmacological screening and controlled studies of neuromuscular diseases.


Assuntos
Reatores Biológicos , Neurônios Motores/efeitos dos fármacos , Células Musculares/efeitos dos fármacos , Junção Neuromuscular/efeitos dos fármacos , Junção Neuromuscular/fisiologia , Animais , Separação Celular , Técnicas de Cocultura , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos/métodos , Estimulação Elétrica , Ácido Glutâmico/química , Proteínas de Fluorescência Verde/metabolismo , Magnetismo , Camundongos , Neurônios Motores/fisiologia , Células Musculares/citologia , Células-Tronco/citologia
10.
Blood ; 125(15): 2418-27, 2015 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-25700434

RESUMO

Coagulation factor replacement therapy for the X-linked bleeding disorder hemophilia is severely complicated by antibody ("inhibitor") formation. We previously found that oral delivery to hemophilic mice of cholera toxin B subunit-coagulation factor fusion proteins expressed in chloroplasts of transgenic plants suppressed inhibitor formation directed against factors VIII and IX and anaphylaxis against factor IX (FIX). This observation and the relatively high concentration of antigen in the chloroplasts prompted us to evaluate the underlying tolerance mechanisms. The combination of oral delivery of bioencapsulated FIX and intravenous replacement therapy induced a complex, interleukin-10 (IL-10)-dependent, antigen-specific systemic immune suppression of pathogenic antibody formation (immunoglobulin [Ig] 1/inhibitors, IgE) in hemophilia B mice. Tolerance induction was also successful in preimmune mice but required prolonged oral delivery once replacement therapy was resumed. Orally delivered antigen, initially targeted to epithelial cells, was taken up by dendritic cells throughout the small intestine and additionally by F4/80(+) cells in the duodenum. Consistent with the immunomodulatory responses, frequencies of tolerogenic CD103(+) and plasmacytoid dendritic cells were increased. Ultimately, latency-associated peptide expressing CD4(+) regulatory T cells (CD4(+)CD25(-)LAP(+) cells with upregulated IL-10 and transforming growth factor-ß (TGF-ß) expression) as well as conventional CD4(+)CD25(+) regulatory T cells systemically suppressed anti-FIX responses.


Assuntos
Fator IX/uso terapêutico , Hemofilia B/terapia , Administração Oral , Transferência Adotiva , Animais , Formação de Anticorpos , Linfócitos T CD4-Positivos/imunologia , Fator IX/administração & dosagem , Fator IX/genética , Fator IX/imunologia , Hemofilia B/imunologia , Humanos , Interleucina-10/imunologia , Masculino , Camundongos , Fitoterapia , Plantas Geneticamente Modificadas/genética , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/uso terapêutico , Nicotiana/genética , Fator de Crescimento Transformador beta/imunologia
11.
Arthritis Rheumatol ; 66(11): 3062-72, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25047145

RESUMO

OBJECTIVE: The discovery of novel disease-modifying drugs for osteoarthritis (OA) is limited by the lack of adequate genetically defined cartilage tissues for application in high-throughput screening systems. We addressed this need by synthesizing cartilage from induced pluripotent stem cells (iPSCs) to establish and validate an in vitro model of OA. METHODS: Native or iPSC-derived mouse cartilage samples were treated with the cytokine interleukin-1α (IL-1α) for 3 days to model the inflammatory environment of OA. The biochemical content, mechanical properties, and gene expression of the resulting tissues were assayed. In addition, the inflammatory and catabolic environment of the media was assessed. To establish high-throughput capability, we used a 96-well plate format and conducted a screen of previously identified candidate OA drugs. Glycosaminoglycan (GAG) release into the medium was used as the primary output for screening. RESULTS: Treatment of iPSC-derived or native cartilage with IL-1α induced characteristic features of OA in a rapid and dose-dependent manner. In addition to the loss of GAGs and tissue mechanical properties, IL-1α treatment induced the expression of matrix metalloproteinases and increased the production of the inflammatory mediators nitric oxide and prostaglandin E2 . In the high-throughput screen validation, all candidate OA therapeutic agents provided some benefit, but only the NF-κB inhibitor SC514 effectively reduced cartilage loss in response to IL-1α. CONCLUSION: This work demonstrates the utility of iPSCs for studying cartilage pathology and provides a platform for identifying novel, patient-specific therapeutic agents that prevent cartilage degradation and modify the course of OA development.


Assuntos
Cartilagem/patologia , Diferenciação Celular , Avaliação Pré-Clínica de Medicamentos/métodos , Osteoartrite/patologia , Células-Tronco Pluripotentes/patologia , Animais , Antirreumáticos/uso terapêutico , Cartilagem/efeitos dos fármacos , Cartilagem/metabolismo , Células Cultivadas , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Glicosaminoglicanos/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Técnicas In Vitro , Interleucina-1alfa/efeitos adversos , Interleucina-1alfa/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Osteoartrite/induzido quimicamente , Osteoartrite/metabolismo , Células-Tronco Pluripotentes/efeitos dos fármacos , Células-Tronco Pluripotentes/metabolismo
12.
Adv Drug Deliv Rev ; 65(6): 800-10, 2013 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-23415952

RESUMO

Oral delivery is an attractive route to deliver therapeutics via nanoparticles due to its ease of administration and patient compliance. This review discusses laboratory techniques for studying oral delivery of nanoparticles, which offer protection of cargo through the gastrointestinal tract. Some of the difficulties in modeling oral delivery include the harsh acidic environment, variable pH, and the tight monolayer of endothelial cells present throughout the gastrointestinal tract. The use of in vitro techniques including the Transwell ® system, simulated gastric/intestinal fluid, and diffusion chambers addresses these challenges. When studying effects after oral delivery in vivo, bioimaging of nanoparticle biodistribution using radioactive markers has been popular. Functional assays such as immune response and systemic protein concentration analysis can further define the merits of the oral delivery systems. As biologics become increasingly more important in chronic therapies, nanoparticle-mediated oral delivery will assume greater prominence, and more sophisticated in vitro and in vivo models will be required.


Assuntos
Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/farmacocinética , Trato Gastrointestinal/metabolismo , Modelos Biológicos , Nanopartículas/administração & dosagem , Administração Oral , Animais , Disponibilidade Biológica , Linhagem Celular , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Testes Hematológicos , Humanos , Imunoensaio , Reação em Cadeia da Polimerase , Cintilografia
13.
Int J Radiat Oncol Biol Phys ; 71(2): 517-25, 2008 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-18407431

RESUMO

PURPOSE: Patients with malignant gliomas have a poor prognosis. To explore a novel and more effective approach for the treatment of patients with malignant gliomas, we designed a strategy that combines caspase-8 (CSP8) gene therapy and radiation treatment (RT). In addition, the specificity of the combined therapy was investigated to decrease the unpleasant effects experienced by the surrounding normal tissue. METHODS AND MATERIALS: We constructed the plasmid pEGR-green fluorescence protein that included the radiation-inducible early growth response gene-1 (Egr-1) promoter and evaluated its characteristics. The pEGR-CSP8 was constructed and included the Egr-1 promoter and CSP8 complementary DNA. Assays that evaluated the apoptosis inducibility and cytotoxicity caused by CSP8 gene therapy combined with RT were performed using U251 and U87 glioma cells. The pEGR-CSP8 was transfected into the subcutaneous U251 glioma cells of nude mice by means of in vivo electroporation. The in vivo effects of CSP8 gene therapy combined with RT were evaluated. RESULTS: The Egr-1 promoter yielded a better response with fractionated RT than with single-dose RT. In the assay of apoptosis inducibility and cytotoxicity, pEGR-CSP8 showed response for RT. The pEGR-CSP8 combined with RT is capable of inducing cell death effectively. In mice treated with pEGR-CSP8 and RT, apoptotic cells were detected in pathologic sections, and a significant difference was observed in tumor volumes. CONCLUSIONS: Our results indicate that radiation-inducible gene therapy may have great potential because this can be spatially or temporally controlled by exogenous RT and is safe and specific.


Assuntos
Neoplasias Encefálicas/terapia , Caspase 8/genética , Terapia Genética/métodos , Glioma/terapia , Plasmídeos/uso terapêutico , Animais , Apoptose , Neoplasias Encefálicas/radioterapia , Caspase 8/uso terapêutico , Terapia Combinada/métodos , Proteína 1 de Resposta de Crescimento Precoce/genética , Proteína 1 de Resposta de Crescimento Precoce/uso terapêutico , Eletroporação/métodos , Técnicas de Transferência de Genes , Genes Reporter/genética , Vetores Genéticos/genética , Vetores Genéticos/uso terapêutico , Glioma/radioterapia , Humanos , Luciferases/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Plasmídeos/genética , Ligante Indutor de Apoptose Relacionado a TNF
14.
Biomaterials ; 25(18): 4327-32, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15046923

RESUMO

The efficacy of a drug delivery system is predicated on its retention in the target tissue. Microparticle is one of the most popular and effective drug delivery configurations. Recently, it has been shown that the interaction between drug-loaded microparticles and tissues is related to the effectiveness of paclitaxel delivery to the bladder wall of mice for treating superficial bladder cancer. In this study, the adhesive interaction between poly(methylidene malonate 2.12) or PMM 2.1.2 microparticles and collagen, which serves as the model extracellular matrix for bladder wall, was probed with confocal reflectance interference contrast microscopy (C-RICM), single-particle compressive force measurement and contact mechanics theory. Young's modulus of single PMM 2.1.2 microparticle was determined as 1.56 +/- 0.25 x 10(4)N/m(2). For plain PMM 2.1.2 microparticle in water (pH 5.5), the degree of deformation (a/R) on collagen coated substrate decreased from 0.77 to 0.26 against the increase of mid-plane diameter from 2 to 18 microm. The adhesion energy of PMM 2.1.2 microparticle was determined from Maguis-JKR theory and remained at around 1.5 mJ/m(2) against the increase of particle diameter. At pH 4, the average degree of particle deformation and adhesion energy was increased by 11% and 32%, respectively, in comparison with that at pH 5.5. The loading of paclitaxel in PMM 2.1.2 microspheres enhanced the deformation and adhesion of microspheres at pH 5.5. It is hypothesized that the electrostatic repulsion between paclitaxel and collagen at pH 4 reduces the adhesion energy of PMM 2.1.2-paclitaxel microsphere. This study may offer insight for design of future microparticulate delivery systems by providing the experimental and theoretical tools to study the bioadhesive interaction between drug-loaded microparticles and model extracellular matrices.


Assuntos
Portadores de Fármacos/química , Matriz Extracelular/química , Malonatos/química , Teste de Materiais/métodos , Paclitaxel/administração & dosagem , Paclitaxel/química , Polietilenos/química , Adesividade , Adsorção , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Sistemas de Liberação de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Elasticidade , Tamanho da Partícula
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