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1.
Am J Dent ; 37(3): 131-135, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38899992

RESUMO

PURPOSE: To explore the function of miR-221-3p in the development and course of chronic periodontitis (CP) and offer a fresh avenue for CP diagnosis and management. METHODS: miR-221-3p expression was detected by RT-qPCR. The clinical diagnostic value of miR-221-3p in CP patients was analyzed by receiver operating characteristic (ROC). ELISA was used to determine the IL-1ß and IL-6 in CP subjects and healthy controls. Pearson correlation analysis was performed with miR-221-3p. PDLCs were induced by LPS, transfected with miR-221-3p mimics, and their expression was analyzed for the effects of IL-1ß, and IL-6. RESULTS: The miR-221-3p expression was lower in the gingival sulcus fluid GCF of CP subjects compared to healthy controls. miR-221-3p showed high potential for clinical diagnosis in CP patients by ROC analysis, with high specificity and sensitivity. miR-221-3p was negatively correlated with Probing pocket depth (PD), Attachment loss (AL), Plaque index (PI), and Bleeding index (BI), and negatively correlated with inflammatory factors IL-1ß and IL-6. In LPS-induced PDLCs, IL-1ß and IL-6 were significantly increased, whereas miR-221-3p was significantly downregulated. Overexpression of miR-221-3p inhibited the production of inflammatory factors IL-1ß and IL-6 in LPS-induced PDLCs. CLINICAL SIGNIFICANCE: miR-221-3p expression may be a potential biological marker for the diagnosis of chronic periodontitis and provide a new direction for its treatment of chronic periodontitis.


Assuntos
Biomarcadores , Periodontite Crônica , Interleucina-1beta , Interleucina-6 , MicroRNAs , Humanos , Periodontite Crônica/metabolismo , Periodontite Crônica/genética , MicroRNAs/genética , Biomarcadores/metabolismo , Masculino , Feminino , Interleucina-6/metabolismo , Interleucina-1beta/metabolismo , Adulto , Pessoa de Meia-Idade , Líquido do Sulco Gengival/metabolismo , Inflamação/metabolismo , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Índice Periodontal , Reação em Cadeia da Polimerase em Tempo Real
2.
Molecules ; 25(2)2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31936531

RESUMO

Among the popular electrochemical energy storage devices, supercapacitors (SCs) have attracted much attention due to their long cycle life, fast charge and discharge, safety, and reliability. Transition metal oxides are one of the most widely used electrode materials in SCs because of the high specific capacitance. Among various transition metal oxides, Co3O4 and related composites are widely reported in SCs electrodes. In this review, we introduce the synthetic methods of Co3O4, including the hydrothermal/solvothermal method, sol-gel method, thermal decomposition, chemical precipitation, electrodeposition, chemical bath deposition, and the template method. The recent progress of Co3O4-containing electrode materials is summarized in detail, involving Co3O4/carbon, Co3O4/conducting polymer, and Co3O4/metal compound composites. Finally, the current challenges and outlook of Co3O4 and Co3O4-containing composites are put forward.


Assuntos
Cobalto/química , Técnicas Eletroquímicas , Eletrodos , Óxidos/química , Capacitância Elétrica , Nanotubos de Carbono/química , Polímeros/química
3.
Langmuir ; 35(38): 12509-12517, 2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-31487459

RESUMO

Polymer topology exerts a significant effect on its properties and performance for potential applications. Cyclic topology and its derived structures have been recently shown to outperform conventional linear analogues for drug delivery applications. However, an amphiphilic tadpole-shaped copolymer consisting of a cylic hydrophobic moiety has rarely been explored. For this purpose, a tadpole-shaped amphiphilic diblock copolymer of poly(ethylene oxide)-b-(cyclic poly(ε-caprolactone)) (mPEG-b-cPCL) was synthesized successfully via ring-opening polymerization (ROP) of ε-CL using a mPEG-based macroinitiator with both a hydroxyl and an azide termini and subsequent intrachain Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAc) click cyclization. A comparison study on the self-assembly behaviors, in vitro drug loading and drug release profiles, and degradation properties of the resulting mPEG-b-cPCL (C) with those of the linear counterpart (mPEG-b-PCL, L) revealed that mPEG-b-cPCL micelles are a better formulation than the micelles formed by the linear counterparts in terms of micelle stability, drug loading capacity, and the degradation property. Interestingly, compared to the single degradation of L, C exhibited a slower two-stage degradation process including the topological change from tadpole shape to linear conformation and the subsequent degradation of a linear polymer. This study therefore uncovered the topological effect of a hydrophobic moiety on the properties of the self-assembled micelles and developed a complementary alternative to enhance the micelle stability by introducing a cyclic hydrophobic segment.


Assuntos
Portadores de Fármacos/química , Micelas , Poliésteres/química , Preparações de Ação Retardada , Doxorrubicina/química , Células HeLa , Humanos , Cinética , Polietilenoglicóis/química
4.
Macromol Rapid Commun ; 39(5)2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29314488

RESUMO

Adaptation of cyclic brush polymer for drug delivery applications remains largely unexplored. Herein, cyclic brush copolymer of poly(2-hydroxyethyl methacrylate-g-poly(N-isopropylacrylamide-st-N-hydroxyethylacrylamide)) (cb-P(HEMA-g-P(NIPAAm-st-HEAAm))), comprising a cyclic core of PHEMA and thermosensitive brushes of statistical copolymer of P(NIPAAm-st-HEAAm), is designed and synthesized successfully via a graft-from approach using atom transfer free radical polymerization from a cyclic multimacroinitiator. The composition of the brush is optimized to endow the resulting cyclic brush copolymer with a lower critical solution temperature (LCST) slightly above the physiological temperature, but lower than the localized temperature of tumor tissue, which is suitable for the hyperthermia-triggered anticancer drug delivery. Critical aggregation concentration determination reveals better stability for the unimolecular nanoparticle formed by the cyclic brush copolymer than that formed by the bottlebrush analogue. The dramatically increased size with elevated temperatures from below to above the LCST confirms hyperthermia-induced aggregation for both formulations. Such structural destabilization promotes significantly the drug release at 40 °C. Most importantly, the drug-loaded cyclic brush copolymer shows enhanced in vitro cytotoxicity against HeLa cells than the bottlebrush counterpart. The better stability and higher therapeutic efficacy demonstrates that the thermosensitive cyclic brush copolymer is a better formulation than bottle brush copolymer for controlled drug release applications.


Assuntos
Antineoplásicos/administração & dosagem , Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Polímeros/química , Temperatura , Resinas Acrílicas/química , Antineoplásicos/química , Antineoplásicos/farmacocinética , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/química , Doxorrubicina/farmacocinética , Portadores de Fármacos/síntese química , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Células HeLa , Humanos , Nanopartículas/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Poli-Hidroxietil Metacrilato/química , Polímeros/síntese química
5.
Mol Pharm ; 12(2): 644-52, 2015 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-25495890

RESUMO

Targeted delivery system would be an interesting platform to enhance the therapeutic effect and to reduce the side effects of anticancer drugs. In this study, we have developed lactobionic acid (LA)-modified chitosan-stearic acid (CS-SA) (CSS-LA) to deliver doxorubicin (DOX) to hepatic cancer cells. The average particle size of CSS-LA/DOX was ∼100 nm with a high entrapment efficiency of >95%. Drug release studies showed that DOX release from pH-sensitive micelles is significantly faster at pH 5.0 than at pH 7.4. The LA conjugated micelles showed enhanced cellular uptake in HepG2 and BEL-7402 liver cancer cells than free drug and unconjugated micelles. Consistently, CSS-LA/DOX showed enhanced cell cytotoxicity in these two cell lines. Annexin-V/FITC and PI based apoptosis assay showed that the number of living cells greatly reduced in this group with marked presence of necrotic and apoptotic cells. LA-conjugated carrier induced typical chromatic condensation of cells; membrane blebbing and apoptotic bodies began to appear. In vivo, CSS-LA/DOX showed an excellent tumor regression profile with no toxic side effects. The active targeting moiety, long circulation profile, and EPR effect contributed to its superior anticancer effect in HepG2 based tumor. Our results showed that polymeric micelles conjugated with LA increased the therapeutic availability of DOX in the liver cancer cell based solid tumor without any toxic side effects. The active targeting ligand conjugated nanoparticulate system could be a promising therapeutic strategy in the treatment of hepatic cancers.


Assuntos
Quitosana/química , Doxorrubicina/administração & dosagem , Doxorrubicina/uso terapêutico , Portadores de Fármacos/química , Neoplasias Hepáticas/tratamento farmacológico , Micelas , Polímeros/química , Ácidos Esteáricos/química , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Dissacarídeos/química , Doxorrubicina/química , Sistemas de Liberação de Medicamentos/métodos , Células Hep G2 , Humanos , Camundongos Nus , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 34(6): 550-5, 2012 Dec.
Artigo em Zh | MEDLINE | ID: mdl-23286397

RESUMO

OBJECTIVE: To compare the efficacy of different expression vectors, target genes, and immunization procedures in transfecting mice via liposome to construct murine model of Graves disease. METHODS: We linked pCDNA3.1(+) and pUBC to full-length human TSHR and TSHR A subunit cDNA to yield four plasmids, which were later injected intramascularly or subcutaneously into female Balb/c mice via liposome. The blood anti-TSHR antibody (TRAb) were determined and the body weight were measured after each immunization. Serum thyroid hormone levels were measured after the animals were sacrificed. RESULTS: In mice immunized with pUBC, no significant variance with control in weight nor serum TRAb concentration was observed. Weight gain in pCDNA3.1(+) group was significantlyly slower than controls (p<0.05), and serum TRAb concentration was also significantly elevated. In pCDNA group, animals immunized with TSHR A subunit (TSHRA subgroup) as the target gene revealed even significantly slower weight gain (p<0.001) and even faster TRAb elevation than those immunized with full length TSHR. Significantly higher FT4 (p=0.023) was observed in TSHRA and TSHR subgroups, which was reversely correlated to weight gain, but no significant difference (p>0.05) in FT3 was observed. Weight gain and TRAb concentration mainly varied in the later period of immunization. CONCLUSIONS: Immunization with pCDNA3.1(+) and TSHR A subunit gene together with higher immunization frequency increases the chance of model induction. Furthermore, FT4 is a better indicator for assessing the thyroid function in this model.


Assuntos
Modelos Animais de Doenças , Doença de Graves/genética , Receptores da Tireotropina/genética , Animais , Feminino , Lipossomos , Camundongos , Camundongos Endogâmicos BALB C , Transfecção
7.
J Control Release ; 345: 278-291, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35306117

RESUMO

Inspired by the biological use of a combination of precision and self-assembly to achieve exquisite control and diversity from 20 natural amino acids, there is considerable scope for the development of synthetic precision materials with complex architecture that can access advanced function for biomedical applications. Single cyclic polymers (SCPs) have been shown to offer different and often better performance compared to their linear analogues. Because multicyclic topology in nature offers enhanced effects relative to single cyclization, we hypothesize that multicyclic polymers (MCPs) would access unique features compared to SCPs. However, there are currently quite limited ways to efficiently synthesize MCPs and to precisely modulate the valency of cyclic units. In this work, we report for the first time a straightforward and robust strategy to synthesize MCPs with controllable valency via facile one-pot statistical reversible addition-fragmentation chain transfer (RAFT) copolymerization. We use this strategy to synthesize biocompatible MCPs based on the most classic and important biocompatible polymers of oligo (ethylene glycol) (OEG) and cyclic poly(ε-caprolactone) (cPCL), which can further self-assemble into well-defined nanostructures. We then apply these MCP-based formulations as drug delivery vehicles and demonstrate greater colloidal stability with a low critical micelle concentration (CMC) of 80.3 nM, larger drug loading capacity, higher cellular uptake efficiency, more tumor accumulation, and increased anti-tumor efficacy in murine tumor models compared to SCP-based analogues. We believe this cumulative work demonstrating facile synthesis of MCPs and demonstration of multicyclic topology-enhanced anti-cancer efficiency in vivo provides key technologies and concepts to the burgeoning field of cyclic topology-derived biomaterials.


Assuntos
Antineoplásicos , Micelas , Animais , Sistemas de Liberação de Medicamentos , Camundongos , Polietilenoglicóis/química , Polimerização , Polímeros/química
8.
ACS Biomater Sci Eng ; 6(5): 2812-2821, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33463294

RESUMO

Facile preparation of hyperbranched polymers (HPs) has been advanced tremendously by the use of either various multifunctional agent-mediated controlled living radical polymerizations or a highly reactive ABx unit-modulated self-stepwise polymerizations. However, it remains, to our knowledge, a significant challenge to prepare HPs with simultaneously precisely controlled degree of branching (DB) and biorelevant signal-triggered degradation property for controlled release applications due to the respective limitations of the aforementioned two strategies. For this purpose, a triple functional AB2 unit, A-SS-B2 chain transfer agent (AB2 CTA), that integrates the merits of both multifunctional agents and highly reactive ABx units was designed and synthesized successfully to include a disulfide bond for reduction-triggered polymer degradation toward promoted intracellular release of encapsulated cargoes, a trithiocarbonate group for a universal reversible addition-fragmentation chain transfer (RAFT) polymerization of any vinyl-based monomer, and three terminal groups consisting of one azide and two alkyne functions for the generation of hyperbranched topology via a self-click coupling-based polymerization. A subsequent self-click polymerization of the resulting AB2 CTA by click coupling in the presence of CuSO4·5H2O and sodium ascorbate (NaVc) generated a hyperbranched polymer template (HPT) with precisely modulated DB and a plurality of CTA units for a universal reversible addition-fragmentation chain transfer (RAFT) polymerization of any vinyl-containing monomer. The HPT was next used as a multimacro-CTA for RAFT polymerization of a typical hydrophilic monomer, oligo(ethylene glycol) monomethyl ether methacrylate (OEGMA), to demonstrate the potential of this HPT for a robust and facile production of bioreducible hyperbranched polymers for controlled release applications. The synthesized HPT-4-POEGMA can form unimolecular micelles with enhanced stability due to the hyperbranched structure, and the size of micelles varied in the range from 82.4 to 140.3 nm by a modulation of the molar feed ratio of monomer to HPT and polymerization time. More importantly, HPT-POEGMA micelles incubated with 10 mM glutathione (GSH) showed reduction-triggered cleavage of the disulfide links and polymer degradation for promoted intracellular doxorubicin (DOX) release and enhanced therapeutic efficiency. Taken together, this triple functional AB2 CTA provided a powerful means for the facile preparation of bioreducible hyperbranched polymers with precisely controlled DB for controlled release applications.


Assuntos
Micelas , Polímeros , Doxorrubicina , Metacrilatos , Polimerização
9.
Biomater Sci ; 8(15): 4206-4215, 2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32555884

RESUMO

Fabrication of cyclic graft (cg) copolymer-based polymeric prodrugs by conjugation of drug molecules to cg copolymers via a dynamic covalent bond capable of responding to biorelevant signals integrates simultaneously the merits of cg copolymers and polymeric prodrugs for enhanced stability of nanocarriers and precise modulation of drug release kinetics. To completely eliminate the compromised drug conjugation efficiency due to the steric hindrance of hydrophilic grafts, it will be useful to develop cg polymeric prodrugs with heterogeneous grafts composed of hydrophilic polymers and drug species, respectively. For this purpose, we reported in this study the synthesis of cyclic graft polymeric prodrugs with heterogeneous grafts of hydrophilic oligo (ethylene glycol) (OEG) and reducibly conjugated camptothecin (CPT), cg-poly(oligo(ethylene glycol) monomethyl ether methacrylate)-b-poly((2-hydroxyethyl methacrylate)-disulfide link-camptothecin) (cg-P(OEGMA)-b-P(HEMA-SS-CPT), cg-prodrugs), via an integrated strategy of a previously reported diblock copolymer-based template and post-polymerization intermolecular click conjugation of a reducible CPT prodrug. The micelles self-assembled from cg-prodrugs on one hand had sufficient salt stability due to the branched cg structure, and on the other hand showed a reduction-triggered cleavage of the disulfide link for a promoted CPT release. Most importantly, we uncovered two interesting phenomena of the cg-based polymeric prodrugs as delivery vehicles: (i) the dimensions of both self-assemblies formed by the cg and bottlegraft (bg) polymers depend substantially on the molecular size of the cg and bg polymers likely due to the steric hindrance of the grafted structures of the cg and bg molecules and relatively low aggregation number of the self-assembled structures, and (ii) cg-prodrug-based micelles exhibited greater in vitro cytotoxicity against cancer cells despite the lower drug loading content (DLC) than the bg-based analogues, which results primarily from the faster reduction-triggered degradation and drug release as well as the greater cellular uptake efficiency of the former micelle prodrugs. Taken together, the developed cg-prodrugs provide great potential for chemotherapy, and the aforementioned interesting results will definitely inspire more upcoming studies on the future design and development of novel cg polymers for biomedical applications.


Assuntos
Pró-Fármacos , Camptotecina , Preparações de Ação Retardada , Micelas , Polietilenoglicóis , Polímeros
11.
Oncol Lett ; 16(3): 3183-3192, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30127913

RESUMO

The aim of the present study was to identify potential biomarkers of hepatocellular carcinoma (HCC). Three gene expression profiles of GSE95698, GSE49515 and GSE76427 and a DNA methylation profile of GSE73003 were downloaded from the Gene Expression Omnibus (GEO) database, each comprising data regarding HCC and control tissue samples. The differentially expressed genes (DEGs) between the HCC group and the control group were identified using the limma software package. The Database for Annotation, Visualization and Integrated Discovery (DAVID) was used to perform Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the overlapping DEGs. The PPI network of the overlapping DEGs was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins. A total of 41 DEGs were identified in HCC the group compared with control group. The overlapping DEGs were enriched in 11 GO terms and 3 KEGG pathways. A total of 6,349 DMSs were identified, and 6 of the differentially expressed genes were also differentially methylated [Denticleless protein homolog (DTL), Dual specificity phosphatase 1 (DUSP1), Eomesodermin, Endothelial cell specific molecule 1, Nuclear factor κ-light-chain gene enhancer of activated B cells inhibitor, α (NFKBIA) and suppressor of cytokine signaling 2 (SOCS2)]. The present study suggested that DTL, DUSP1, NFKBIA and SOCS2 may be potential biomarkers of HCC, and the tumor protein 'p53 signaling', 'forkhead box O1' signaling and 'metabolic' pathways may serve roles in the pathogenesis of HCC.

12.
Macromol Biosci ; 18(7): e1800022, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29745057

RESUMO

The cyclic brush polymers, due to the unique topological structure, have shown in the previous studies higher delivery efficacy than the bottlebrush analogues as carriers for drug and gene transfer. However, to the best of knowledge, the preparation of reduction-sensitive cyclic brush polymers for drug delivery applications remains unexplored. For this purpose, a reduction-sensitive amphiphilic cyclic brush copolymer, poly(2-hydroxyethyl methacrylate-g-poly(ε-caprolactone)-disulfide link-poly(oligoethyleneglycol methacrylate)) (P(HEMA-g-PCL-SS-POEGMA)) with reducible block junctions bridging the hydrophobic PCL middle layer and the hydrophilic POEGMA outer corona is designed and synthesized successfully in this study via a "grafting from" approach using sequential ring-opening polymerization (ROP) and atom transfer free radical polymerization (ATRP) from a cyclic multimacroinitiator PHEMA. The resulting self-assembled unimolecular core-shell-corona (CSC) micelles show sufficient salt stability and efficient destabilization in the intracellular reducing environment for a promoted drug release toward a greater therapeutic efficacy relative to the reduction-insensitive analogues. The overall results demonstrate the reducible cyclic brush copolymers developed herein provides an elegant solution to the tradeoff between extracellular stability and intracellular high therapeutic efficacy toward efficient anticancer drug delivery.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Preparações de Ação Retardada/síntese química , Doxorrubicina/farmacologia , Metacrilatos/química , Poliésteres/química , Polietilenoglicóis/química , Antibióticos Antineoplásicos/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Preparações de Ação Retardada/química , Doxorrubicina/metabolismo , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Radicais Livres/química , Células HeLa , Humanos , Interações Hidrofóbicas e Hidrofílicas , Cinética , Micelas , Oxirredução , Tamanho da Partícula , Polimerização
13.
Colloids Surf B Biointerfaces ; 125: 34-44, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25460599

RESUMO

Biodegradable polyurethane (PU) was synthesized by a water-based process. The process rendered homogenous PU nanoparticles (NPs). Spongy PU scaffolds in large dimensions were obtained by freeze-drying the PU NP dispersion. The spongy scaffolds were characterized in terms of the porous structure, wettability, mechanical properties, degradation behavior, and degradation products. The capacity as cartilage tissue engineering scaffolds was evaluated by growing chondrocytes and mesenchymal stem cells (MSCs) in the scaffolds. Scaffolds made from the PU dispersion had excellent hydrophilicity, porosity, and water absorption. Examination by micro-computed tomography confirmed that PU scaffolds had good pore interconnectivity. The degradation rate of the scaffolds in phosphate buffered saline was much faster than that in papain solution or in deionized water at 37°C. The biodegradable PU appeared to be degraded via the cleavage of ester linkage The intrinsic elastic property of PU and the gyroid-shape porous structure of the scaffolds may have accounted for the outstanding strain recovery (87%) and elongation behavior (257%) of the PU scaffolds, compared to conventional poly(d,l-lactide) (PLA) scaffolds. Chondrocytes were effectively seeded in PU scaffolds without pre-wetting. They grew better and secreted more glycosaminoglycan in PU scaffolds vs. PLA scaffolds. Human MSCs showed greater chondrogenic gene expression in PU scaffolds than in PLA scaffolds after induction. Based on the favorable hydrophilicity, elasticity, and regeneration capacities, the novel biodegradable PU scaffolds may be superior to the conventional biodegradable scaffolds in cartilage tissue engineering applications.


Assuntos
Materiais Biocompatíveis/farmacologia , Condrócitos/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Poliuretanos/farmacologia , Alicerces Teciduais , Ânions , Materiais Biocompatíveis/química , Biomarcadores/metabolismo , Cartilagem/citologia , Cartilagem/efeitos dos fármacos , Cartilagem/metabolismo , Proliferação de Células/efeitos dos fármacos , Condrócitos/citologia , Condrócitos/metabolismo , Glicosaminoglicanos/biossíntese , Glicosaminoglicanos/metabolismo , Humanos , Hidrólise , Interações Hidrofóbicas e Hidrofílicas , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Poliésteres/química , Poliésteres/farmacologia , Poliuretanos/química , Porosidade , Cultura Primária de Células , Engenharia Tecidual , Molhabilidade , Microtomografia por Raio-X
14.
Colloids Surf B Biointerfaces ; 104: 66-74, 2013 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-23298590

RESUMO

Biocompatibility is a critical factor in the design and development of candidate materials for biomedical use. This paper reports on the in vitro biocompatibility of magnetic stimuli-sensitive nanohydrogel particles composed of magnetite cores in poly(N-isopropylacrylamide-co-acrylic acid) shells referred to Fe(3)O(4)/P(NIPAAm-co-AAc). The AAc concentration and polymerization time were varied to fabricate magnetic nanoparticles with various AAc levels (1.80-2.37%) and particle sizes (74-213 nm). The P(NIPAAm-co-AAc) shell exhibited thermo-sensitive properties and the Fe(3)O(4) core constituted 2.25-4.10% of the particles by weight. After a 2-day incubation of L929 cells with extract media that had been conditioned with various test samples, the cellular responses were monitored in terms of cell viability and growth. The Live/Dead assays showed that high levels of cellular viability (97.3-98.1%) were observed in all groups, indicating that none of the nanoparticles were cytotoxic. However, the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymetho-xyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assays demonstrated that the activity of mitochondrial dehydrogenase varied significantly in cultures exposed to different magnetic nanohydrogel particles. The murine fibroblasts exposed to the NIP-(AAc5.1-Fe)-2 sample, which contained the highest AAc content and largest particle sizes, were the least metabolically active. In contrast, the activity levels in the cultures treated with the low AAc content and small size particles (NIP-(AAc2.6-Fe)-1) were not significantly different from those in the control group. Our findings suggest that smaller magnetic stimuli-sensitive nanohydrogel particles with a lower AAc content may have little inhibitory impact on cell proliferation. Overall, the in vitro biocompatibilities of the nanoparticles depend on the chemical composition and size of the Fe(3)O(4)/P(NIPAAm-co-AAc) particles.


Assuntos
Acrilamidas/farmacologia , Materiais Biocompatíveis/farmacologia , Compostos Férricos/farmacologia , Hidrogéis/farmacologia , Nanopartículas/química , Polímeros/farmacologia , Temperatura , Acrilamidas/química , Animais , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Compostos Férricos/química , Hidrogéis/química , Campos Magnéticos , Camundongos , Tamanho da Partícula , Polímeros/química , Relação Estrutura-Atividade , Propriedades de Superfície
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