RESUMO
Waste-activated sludge (WAS) with trace organic pollutants, e.g., polycyclic aromatic hydrocarbons (PAHs), has become an environmental concern. Anaerobic technology is a feasible option for WAS treatment due to its advantages of low-energy consumption and high-energy recovery compared to aerobic technology, but it still has many shortcomings, such as low biogas production and a low organic pollutant removal efficiency. Thus, this study investigated the effects of cellulose on PAHs degradation and microbial community structure variation during anaerobic digestion of sewage sludge. Four semicontinuous experiments were set by adding cellulose to sewage sludge based on the volatile solids (VS) concentration. The proportions of sludge VS to cellulose VS were 1:0 (CK), 1:0.2, 1:0.5 and 1:1. The results showed the following: (1) The biodegradation of 2-ring, 3-ring and 4-ring PAHs was enhanced by cellulose addition, with total PAHs removal efficiencies of 14.82%, 20.75% and 19.35%, respectively. (2) The abundance of bacteria that could degrade PAHs, such as Chloroflexi, Bacteroidetes, Aminicenantes, Planctomycetes and Spirochaeta, was obviously increased by cellulose addition. (3) The abundance of Methanosaeta during sludge anaerobic digestion was apparently increased by cellulose addition. Methanobacterium and Methanolinea appeared after cellulose addition, while they were not observed in the blank experiment.
Assuntos
Celulose/farmacologia , Microbiota/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/análise , Esgotos , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Anaerobiose , Biodegradação Ambiental , Biocombustíveis/análise , Celulose/metabolismo , Esgotos/química , Esgotos/microbiologiaRESUMO
An ultralarge sheet with remarkable lateral dimensions of 10 µm × 10 µm-20 µm × 20 µm is fabricated by the hierarchical self-assembly of porphyrin-ended hyperbranched poly(ether amine) (tetraphenylporphyrin (TPP)-hPEA) in solution. The obtained TPP-hPEA amphiphiles can self-assemble from ultrathin single-layered nanosheets with a thickness of 4 nm to ultralarge multilayered nanosheets with thicknesses from 30 to 70 nm. The lateral dimensions increase from 2 × 2 µm to 5 × 5 µm, and eventually to 10 × 10 µm. In-situ dynamic light scattering and UV-vis spectroscopy studies suggest a hierarchical growth self-assembly mechanism with a self-assembly process that relies on π-π stacking. This 2D self-assembly method provides a significant potential guide for the preparation of ultralarge nanosheets in solution.
Assuntos
Nanoestruturas/química , Polímeros/química , Porfirinas/química , Aminas/química , Éteres/química , Polímeros/síntese química , Porfirinas/síntese químicaRESUMO
Dental pulp stem cells (DPSCs) are a type of mesenchymal stem cell (MSC) characterized by multi-lineage differentiation making it an attractive choice for tissue regeneration. However, before DPSCs can be used for cell-based therapy, we have to understand their biological properties in response to intrinsic and extrinsic stimuli such as lipopolysaccharide (LPS). DPSCs were therefore stimulated with LPS and senescence was evaluated by senescence-associated ß-galactosidase (SA-ß-gal) staining, with cell number and cell-cycle arrest being examined by BrdU assay and flow cytometry, respectively. The morphology of DPSCs was characterized by their flat shape, increased size and increased SA-ß-gal activity after repeated stimulation (3 or 6 times) with LPS. Reactive oxygen species (ROS) staining showed that the number of ROS-stained cells and the DCFH fluorescent level were higher in the LPS-treated DPSCs compared with those in the untreated DPSCs. Protein and mRNA expression levels of γ-H2A.X and p16(INK4A) were also increased in DPSCs with repeated LPS stimulation. We found that the LPS bound with Toll-like receptor 4 (TLR4) and that TLR4 signaling accounted for p16(INK4A) expression. Further results indicated that the senescence of DPSCs stimulated repeatedly with LPS was reversed by p16(INK4A) short interfering RNA. The DNA damage response and p16(INK4A) pathways might be the main mediators of DPSC senescence induced by repeated LPS stimulation. Thus, DPSCs tend to undergo senescence after repeated activation, implying that DPSC senescence starts after many inflammatory challenges. Ultimately, these findings should lead to a better understanding of DPSC-based clinical therapy.
Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Polpa Dentária/citologia , Células-Tronco Mesenquimais/citologia , Dente Serotino/citologia , Receptor 4 Toll-Like/metabolismo , Adolescente , Adulto , Apoptose , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Senescência Celular , Inibidor p16 de Quinase Dependente de Ciclina/biossíntese , Inibidor p16 de Quinase Dependente de Ciclina/genética , Reparo do DNA , Histonas/biossíntese , Humanos , Lipopolissacarídeos , Ligação Proteica , Interferência de RNA , RNA Mensageiro/biossíntese , RNA Interferente Pequeno , Espécies Reativas de Oxigênio/metabolismo , Adulto Jovem , beta-GalactosidaseRESUMO
Insulin-like growth factor 1 (IGF-1) is a multifunctional peptide that can enhance osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs). However, it remains unclear whether IGF-1 can promote osteogenic differentiation of human dental pulp stem cells (DPSCs). In our study, DPSCs were isolated from the impacted third molars, and treated with IGF-1. Osteogenic differentiation abilities were investigated. We found that IGF-1 activated the mTOR signaling pathway during osteogenic differentiation of DPSCs. IGF-1 also increased the expression of runt-related transcription factor 2 (RUNX2), osteocalcin (OCN), osterix (OSX) and collagen type I (COL I) during this process. Rapamycin, an mTOR inhibitor, blocked osteogenic differentiation induced by IGF-1. Meanwhile, CCK-8 assay and flow cytometry results demonstrated that 10-200 ng/mL IGF-1 could enhance proliferation ability of DPSCs and 100 ng/mL was the optimal concentration. In summary, IGF-1 could promote proliferation and osteogenic differentiation of DPSCs via mTOR pathways, which might have clinical implications for osteoporosis.
Assuntos
Proliferação de Células/fisiologia , Polpa Dentária/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Osteogênese/fisiologia , Transdução de Sinais/fisiologia , Células-Tronco/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Adolescente , Adulto , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Proliferação de Células/efeitos dos fármacos , Polpa Dentária/citologia , Feminino , Humanos , Fator de Crescimento Insulin-Like I/farmacologia , Masculino , Osteogênese/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Células-Tronco/citologiaRESUMO
Dental pulp stem cells (DPSCs) are a type of mesenchymal stem cells (MSCs) characterised by self-renewal and multi-lineage differentiation, including chondrocytes, adipocytes, neural cells and osteoblasts, which make it an attractive choice for tissue engineering purposes. Tumour necrosis factor α (TNF-α) had the positive effect on the mineralisation of bone marrow MSCs and stromal cells derived from human adipose tissue. However, the effect of TNF-α on DPSCs is unclear. We found that TNF-α activated the NF-κB pathway during the osteogenic differentiation of DPSCs. TNF-α also increased mineralisation and the expression of bone morphogenetic protein 2 (BMP2), alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2) and collagen type I (COL I) during this process. PDTC, an NF-κB inhibitor, blocked the osteogenic differentiation induced by TNF-α. No effect of TNF-α on proliferation of DPSCs or cell cycle was detected. In summary, TNF-α promotes mineralisation and mineralisation-related gene expression through the NF-κB signalling pathway in DPSCs, which may provide a foundation for autologous transplantation of DPSCs.
Assuntos
Polpa Dentária/citologia , NF-kappa B/metabolismo , Osteogênese/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia , Adolescente , Fosfatase Alcalina/metabolismo , Proteína Morfogenética Óssea 2/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Colágeno Tipo I/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Humanos , NF-kappa B/antagonistas & inibidores , Prolina/análogos & derivados , Prolina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Células-Tronco/citologia , Células-Tronco/metabolismo , Tiocarbamatos/farmacologia , Adulto JovemRESUMO
Bladder tumor is a malignant tumor on bladder mucosa and the most common malignant tumor of urinary system. At present, bladder cancer is mainly treated by surgical resection and intravesical infusion of anticancer drugs. The high-molecular nano-drug-loading system has the advantages of direct focus of the drug in the treatment of cancer, reduced systemic toxicity and high local concentration. The purpose of this paper was to study the effect of polymer nano-drug loading system on bladder cancer perfusion. The synthesized polymer was applied to the establishedmouse bladder cancer model, the anticancer effect of polymer nano-drug loading system on mice in vivo was observed, and the health status of mice during administration was determined. It was found that a large number of drugs could adhere to the tumor tissue after perfusion of bladder cancer with polymer nano-drug loading system, and the effect of killing bladder cancer cells was better.
Assuntos
Preparações Farmacêuticas , Neoplasias da Bexiga Urinária , Administração Intravesical , Animais , Linhagem Celular Tumoral , Camundongos , Perfusão , Polímeros , Neoplasias da Bexiga Urinária/tratamento farmacológicoRESUMO
A high-performance flexible conductive substrate is one of the key components for developing promising wearable devices. Concerning this, a sustainable, flexible, transparent, and conductive cellulose/ZnO/AZO (CZA) film was developed in this study. The cellulose was used as the transparent substrate. The added AZO was as the conductive layer and ZnO functioned as an interface buffer layer. Results showed that the interface buffer layer of ZnO effectively alleviated the intrinsic incompatibility of organic cellulose and inorganic AZO, resulting in the improvement of the performance of CZA film. In compared with the controlled cellulose/AZO (CA) film with 365 Ω/sq sheet resistance and 87% transmittance, this CZA film featured a low conductive sheet resistance of 115 Ω/sq and high transmittance of 89%, as well as low roughness of 1.85 nm Moreover, the existence of conducive ZnO buffer layer enabled the conductivity of CZA film to be stable under the bending treatment. Herein, a flexible electronic device was successfully prepared with the biomass materials, which would be available by a roll-to-roll production process.
Assuntos
Celulose/química , Eletrônica , Alumínio/química , Condutividade Elétrica , Óxido de Zinco/químicaRESUMO
We have determined the production profiles of major ligno(hemi)cellulolytic enzymes at different stages of the mushroom development cycle during industrial scale cultivation of Pleurotus eryngii on supplemented agri-wastes. Endo-1,4-ß-glucanase, cellobiohydrolase and endoxylanase levels remained relatively low during substrate colonization, increased sharply when small fruit bodies appeared, and peaked at maturation. ß-Glucosidase and ß-xylosidase levels decreased when substrate colonization was complete, increased with the appearance of small fruit bodies and primordia, respectively, and reached maxima at maturation. Laccase peaked along with substrate colonization but, after falling sharply in the upper substrate layers, remained relatively low until postinduction. Levels increased slightly when primordia appeared, fell to minimal values during the small and mature fruit body stages, and increased again postharvest. Manganese peroxidase (Mn-P) exhibited a similar pattern initially but high enzyme levels also coincided with primordia formation. Laccase and Mn-P activity patterns were compatible with a lignin-degradation function associated with substrate colonization and, in the former case, a putative role in fruit body morphogenesis. Based on the relatively low levels of polysaccharidases recorded during the initial stages of substrate colonization, we conclude that reducing sugar levels in noncolonized substrate were adequate for sustainable vegetative growth at that stage. We further conclude that the increase in enzyme production later in the developmental cycle was consistent with the replenishment of depleted reducing sugar from cellulose in the growth substrate to levels required for fruit body formation. These data provide new information describing combined temporal and spatial enzyme production profiles throughout the mushroom development cycle under a set of conditions used in industrial scale production.
Assuntos
Proteínas Fúngicas/metabolismo , Pleurotus/enzimologia , Pleurotus/crescimento & desenvolvimento , Resíduos/análise , Agricultura , Celulose 1,4-beta-Celobiosidase/metabolismo , Meios de Cultura/análise , Meios de Cultura/metabolismo , Endo-1,4-beta-Xilanases/metabolismo , Carpóforos/enzimologia , Carpóforos/crescimento & desenvolvimento , Lacase/metabolismo , Lignina/metabolismo , Peroxidases/metabolismo , Pleurotus/genéticaRESUMO
One approach to improve the targeted therapeutic efficiency of lung cancer is to deliver drugs using nano-scaled systems. In this study, RGD peptide-modified, paclitaxel (PTX) prodrug-based, dual-drugs loaded, and redox-sensitive lipid-polymer nanoparticles were developed and the in vitro and in vivo antitumor efficiency was evaluated in lung cancer cells and tumor bearing animal models. RGD-modified PTX and cisplatin (CDDP) loaded LPNs (RGD-ss-PTX/CDDP LPNs) have sizes around 190â¯nm, and zeta potentials of -35â¯mV. The half-maximal inhibitory concentration (IC50) values were 26.7 and 75.3⯵g/mL for drugs loaded LPNs and free drugs combination, which indicates significantly higher antitumor activity of LPNs than free drugs. RGD-ss-PTX/CDDP LPNs also exhibited the best antitumor efficiency in vivo, which inhibited the tumor size of mice from 1486 mm3 to 263 mm3. The results illustrated that the system could successfully load drugs and achieve synergistic combination lung cancer treatment efficiency with lower systemic toxicity compared with free drugs counterparts. The resulting system could be facilitated as a promising targeted nanomedicine for the treatment of lung cancer.
Assuntos
Antineoplásicos/administração & dosagem , Portadores de Fármacos , Lipídeos/química , Neoplasias Pulmonares/tratamento farmacológico , Nanopartículas , Oligopeptídeos/metabolismo , Paclitaxel/administração & dosagem , Polímeros/química , Pró-Fármacos/administração & dosagem , Células A549 , Animais , Antineoplásicos/sangue , Antineoplásicos/química , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/administração & dosagem , Relação Dose-Resposta a Droga , Composição de Medicamentos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Sinergismo Farmacológico , Humanos , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/patologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanomedicina , Oligopeptídeos/química , Oxirredução , Paclitaxel/análogos & derivados , Paclitaxel/sangue , Paclitaxel/química , Pró-Fármacos/química , Pró-Fármacos/metabolismo , Tecnologia Farmacêutica/métodos , Distribuição Tecidual , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
In order to describe iron stability in plastic pipes and to ensure the drinking water security, the influence factors and rules for iron adsorption and release were studied, dependent on the Unplasticized poly (vinyl chloride) (PVC-U) drinking pipes employed in this research. In this paper, sulfate, chloride, and bicarbonate, as well as synthesized models, were chosen to investigate the iron stability on the inner wall of PVC-U drinking pipes. The existence of the three kinds of anions could significantly affect the process of iron adsorption, and a positive association was found between the level of anion concentration and the adsorption rate. However, the scaling formed on the inner surface of the pipes would be released into the water under certain conditions. The Larson Index (LI), used for a synthetic consideration of anion effects on iron stability, was selected to investigate the iron release under multi-factor conditions. Moreover, a well fitted linear model was established to gain a better understanding of iron release under multi-factor conditions. The simulation results demonstrated that the linear model was better fitted than the LI model for the prediction of iron release.
Assuntos
Ferro/química , Poluentes Químicos da Água/análise , Abastecimento de Água , Adsorção , Bicarbonatos/análise , Cloretos/análise , Cloreto de Polivinila/análise , Sulfatos/análiseRESUMO
OBJECTIVE: To study the conditions and parameters of purifying 2,3,5,4'-tetrahydroxy-stilbene-2-O-beta-D-glycoside from Polygonum multiflori. METHOD: Absorption capacity of four resins for 2,3,5,4'-tetrahydroxy-stilbene-2-O-beta-D-glycoside was compared. With the adsorption ability as indexes, the process of absorbing and purifying 2,3,5,4'-tetrahydroxy-stilbene-2-O-beta-D-glycoside from P. multiflori with S-8 macroporous resin absorbent was selected by orthogonal design. RESULT: The S-8 resin was the best of the four resins. The optimum process condition was 50% ethanol as eluting solvent, the flow rate at 1.5 mL x min(-1), pH at 7-8, and the solution concentration at 0.2 g x mL(-1). The absorption capacity by this process was 36.89 mg x g(-1). CONCLUSION: The process is simple and convenient and the regeneration of resin is easy, so this method of purification is advisable.
Assuntos
Glicosídeos/isolamento & purificação , Plantas Medicinais/química , Polygonum/química , Estilbenos/isolamento & purificação , Absorção , Glicosídeos/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Resinas Sintéticas/química , Estilbenos/químicaRESUMO
The update of pipeline was quick over the last few years and the plastic pipes were widely used in the drinking water distribution systems (DWDSs), especially in the small-diameter pipes. In this study, the iron adsorptive characteristics and the affecting factors in unplasticized poly(vinyl chloride) (PVC-U) pipe were investigated. Results showed that the average amount of iron in the 10-year-old PVC-U pipe's interior surface was 2.80 wt% which was almost 187 times larger than that in a new one. Goethite (α-FeOOH) and magnetite (Fe3O4) were the major iron compounds in the scales which covered on the old pipes' interior surface and showed loose and porous images under a scanning electron microscope. Moreover, the influence of the iron concentration on the adsorption amount and rate was discussed. The adsorption amount was significantly influenced by iron concentration, but similar adsorption rate was discovered. Notably, iron was quantitatively adsorbed by PVC-U pipe during the experimental period in accordance with the pseudo second order kinetic model. Meanwhile, regression model and response surface methodology were used to analyze the regular of iron adsorption in different concentrations of chloride (Cl-), sulfate (SO42-), and hydroxyl (OH-). It can be concluded that Cl- and OH- showed the strong ability of iron adsorption which were larger than SO42-.
Assuntos
Água Potável/análise , Compostos de Ferro/análise , Minerais/análise , Cloreto de Polivinila/química , Poluentes Químicos da Água/análise , Adsorção , Cloretos/análise , Radical Hidroxila/análise , Ferro , Cinética , Sulfatos/análiseRESUMO
Polyrotaxane metal-organic frameworks (PMOFs) have attracted considerable attention due to their aesthetic topologies and potential biological applications. In this paper, we synthesized two kinds of hcb networks with nanoscale macrocycles. The hcb networks interlocked with each other in inclined and parallel interlocking modes respectively, giving rise to two new PMOFs, {[Ni(DPDBT)(bdc)]·(H2O)2}n (1) and {[Zn(DPDBT)(fuma)]}n (2). DFT calculations are used to elucidate why the inclined interlocking mode is preferential for 1 while the parallel interlocking mode is preferential for 2. The networks of 1 with a parallel interlocking mode, as well as 2 with an inclined interlocking mode, were simulated. The total energies of the parallel and inclined structures proved that the as-synthesized interlocking modes of 1and 2 are more stable. Moreover, photophysical properties and thermal analyses of related ligands and complexes are investigated and discussed in detail.
Assuntos
Ciclodextrinas/química , Compostos Organometálicos/química , Poloxâmero/química , Teoria Quântica , Rotaxanos/química , Modelos Moleculares , Conformação Molecular , Temperatura , Zinco/químicaRESUMO
BACKGROUND: Amoxicillin is a commonly used antibiotic which has a short half-life in human. The frequent administration of amoxicillin is often required to keep the plasma drug level in an effective range. The short dosing interval of amoxicillin could also cause some side effects and drug resistance, and impair its therapeutic efficacy and patients' compliance. Therefore, a three-pulse release tablet of amoxicillin is desired to generate sustained release in vivo, and thus to avoid the above mentioned disadvantages. METHODS: The pulsatile release tablet consists of three pulsatile components: one immediate-release granule and two delayed release pellets, all containing amoxicillin. The preparation of a pulsatile release tablet of amoxicillin mainly includes wet granulation craft, extrusion/spheronization craft, pellet coating craft, mixing craft, tablet compression craft and film coating craft. Box-Behnken design, Scanning Electron Microscope and in vitro drug release test were used to help the optimization of formulations. A crossover pharmacokinetic study was performed to compare the pharmacokinetic profile of our in-house pulsatile tablet with that of commercial immediate release tablet. The pharmacokinetic profile of this pulse formulation was simulated by physiologically based pharmacokinetic (PBPK) model with the help of Simcyp®. RESULTS AND DISCUSSION: Single factor experiments identify four important factors of the formulation, namely, coating weight of Eudragit L30 D-55 (X1), coating weight of AQOAT AS-HF (X2), the extrusion screen aperture (X3) and compression forces (X4). The interrelations of the four factors were uncovered by a Box-Behnken design to help to determine the optimal formulation. The immediate-release granule, two delayed release pellets, together with other excipients, namely, Avicel PH 102, colloidal silicon dioxide, polyplasdone and magnesium stearate were mixed, and compressed into tablets, which was subsequently coated with Opadry® film to produce pulsatile tablet of amoxicillin. In vitro release study firstly indicated a three-pulse release profile of the tablet. Later the pulse tablet was found to generate the sustained release of amoxicillin in beagle dogs. Furthermore, the Simcyp® software was used to simulate the in vivo concentration time curve model of the three-pulse release tablet for amoxicillin in both human and beagle dog. The prediction by PBPK model nicely fitted the observation in human and beagle dog. CONCLUSIONS: This study has demonstrated the interrelation of factors affecting the pulsatile formulation of amoxicillin using a Box-Behnken design. The three-pulse release tablets of amoxicillin were proven to generate pulsatile release in vitro and sustained release in vivo. This formulation was also found to extend the effective plasma concentration in human compared to the tablet of immediate release based on the simulation data by PBPK modeling. This study provides an example of using PBPK to guide the development of pulsatile dosage forms.
Assuntos
Amoxicilina/farmacocinética , Comprimidos/química , Amoxicilina/química , Amoxicilina/metabolismo , Animais , Área Sob a Curva , Preparações de Ação Retardada , Cães , Composição de Medicamentos , Liberação Controlada de Fármacos , Meia-Vida , Humanos , Masculino , Metacrilatos/química , Microscopia Eletrônica de Varredura , Modelos Teóricos , Polímeros/química , Curva ROCRESUMO
OBJECTIVE: To determine the contents of tetrandine in tetrandine microsphere for the quality control of the preparation. METHOD: Tetradine in microsphere was determined by spectrophotometry of standard curve. RESULT: The content of tetrandine was 44.5% +/- 0.26% (n=3). CONCLUSION: The method was simple, rapid and accurate.
Assuntos
Alcaloides/análise , Benzilisoquinolinas/análise , Medicamentos de Ervas Chinesas/química , Menispermaceae/química , Plantas Medicinais/química , Medicamentos de Ervas Chinesas/análise , Ácido Láctico , Microesferas , Tubérculos/química , Poliésteres , Polímeros , Espectrofotometria Ultravioleta/métodosRESUMO
We have manufactured a highly conductive and stretchable composite by backfilling a preformed graphene/MWCNT aerogel with poly(dimethylsiloxane) (PDMS). The electrical conductivity of our product can reach 2.8 S cm(-1) with only 1.3 wt% graphene/MWCNT loading, and remains constant after 100 times repeated stretching by 20% and 5000 times bending.
Assuntos
Grafite/química , Nanotubos de Carbono/química , Polímeros/química , Dimetilpolisiloxanos/química , Condutividade Elétrica , Tamanho da Partícula , Propriedades de SuperfícieRESUMO
OBJECTIVE: Theaflavin (TF) from the black tea can react to human salivary proline-rich proteins (PRPs) to form stains on exposed dental surfaces. Here, we employed a model of protein/pigment film using TF and dephosphorylated bovine ß-casein (Dß-CN), which has an extended conformation, similar to that of salivary PRPs, on a sensor surface to assess the efficacy of cysteine proteases (CPs) including papain, stem bromelain, and ficin, on removing TF bound to Dß-CN and the control TF readsorption on the residual substrate surfaces was also measured. METHODS: The protein/pigment complex film was built by using a quartz crystal microbalance with dissipation (QCM-D). The efficacies of CPs were assessed by Boltzman equation model. The surface details were detected by grazing angle infrared spectroscopy spectra, atomic force microscopy images, and contact angles. RESULTS: The efficacy order of CPs on hydrolyzing protein/pigment complex film is ficin>papain>bromelain. The results from grazing angle infrared spectroscopy spectra, atomic force microscopy images, and contact angles demonstrated that TF bound on the Dß-CN was effectively removed by the CPs, and the amount of TF readsorption on both the residual film of the Dß-CN/TF and the Dß-CN was markedly decreased after hydrolysis. CONCLUSION: This study indicates the potential application of the CPs for tooth stain removal and suggests that these enzymes are worthy of further investigation for use in oral healthcare.
Assuntos
Antioxidantes/farmacologia , Biflavonoides/química , Catequina/química , Cisteína Endopeptidases/farmacologia , Proteínas Salivares Ricas em Prolina/química , Chá/química , Descoloração de Dente/tratamento farmacológico , Animais , Antioxidantes/uso terapêutico , Biflavonoides/metabolismo , Bromelaínas/farmacologia , Caseínas/química , Catequina/metabolismo , Bovinos , Cisteína Endopeptidases/uso terapêutico , Ficina/farmacologia , Humanos , Hidrólise , Microscopia de Força Atômica , Papaína/farmacologia , Técnicas de Microbalança de Cristal de Quartzo , Proteínas Salivares Ricas em Prolina/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de SuperfícieRESUMO
BACKGROUND: Integrins α(v)ß(3) and α(v)ß(5), both of which specifically recognize the Arg-Gly-Asp (RGD) motif, are overexpressed on many solid tumors and in tumor neovasculature. Thus, coupling the RGD motif to the liposomal surface for achieving active targeting can be a promising strategy for the treatment of tumors. METHODS: Cyclo(Arg-Gly-Asp-D-Phe-Cys) (cRGD) was covalently coupled with the liposomal membrane surface, followed by coating with poly(ethylene glycol) (PEG) using the post-insertion technique. The coupling efficiency of cRGD was determined. Doxorubicin as a model anticancer drug was loaded into liposomes using an ammonium sulfate gradient method to investigate the encapsulation efficiency, cellular uptake by the integrin-overexpressing human glioma cell line U87MG in vitro, and pharmacokinetic properties in Sprague-Dawley rats. RESULTS: cRGD was conjugated to the liposomal surface by a thiol-maleimide coupling reaction. The coupling efficiency reached 98%. The encapsulation efficiency of doxorubicin in liposomes was more than 98%. The flow cytometry test result showed that cRGD-modified liposomes (RGD-DXRL-PEG) had higher cell uptake by U87MG cells, compared with nontargeted liposomes (DXRL-PEG). The cellular uptake was significantly inhibited in the presence of excess free cRGD. Both the targeted (t(1/2) = 24.10 hours) and non-targeted (t(1/2) = 25.32 hours) liposomes showed long circulating properties in rat plasma. The area under the curve of the targeted and nontargeted liposomes was 6.4-fold and 8.3-fold higher than that of doxorubicin solution, respectively. CONCLUSION: This study indicates preferential targeting and long circulating properties for cRGD-modified liposomes in vivo, which could be used as a potential targeted liposomal drug delivery system to treat human glioma.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Lipossomos/farmacocinética , Oligopeptídeos/química , Análise de Variância , Animais , Linhagem Celular Tumoral , Doxorrubicina/administração & dosagem , Doxorrubicina/sangue , Doxorrubicina/química , Doxorrubicina/farmacocinética , Estabilidade de Medicamentos , Citometria de Fluxo , Glioma/metabolismo , Humanos , Lipossomos/administração & dosagem , Lipossomos/química , Oligopeptídeos/administração & dosagem , Oligopeptídeos/farmacocinética , Polietilenoglicóis , Ratos , Ratos Sprague-DawleyRESUMO
OBJECTIVE: To evaluate the thickness and viscoelasticity of whole saliva (WS), parotid saliva (PS) and submandibular/sublingual gland saliva (SMSLS) film adsorption on the hydroxyapatite (HA) surface. METHODS: Ultra-thin layer of HA nanocrystals was coated on the dissipation TiO(2) sensor of gold quartz crystal microbalance using electrophoretic deposition technique. The thickness of the HA layer was measured by the ellipsometer, and element analysis was conducted using X-ray photoelectron spectroscopy. Atomic force microscopy and scanning electron microscope were used to observe its morphology. The in-situ adsorption thickness, the shear elastic modulus and the shear viscosity of salivary layers (WS, PS and SMSLS) on HA surfaces were investigated. The statistical data were analysed by an one-way ANOVA analysis followed by a SNK-q test. RESULTS: The results show that the HA layer was a plate-like morphology with 1.53 ± 0.12 in Ca/P molar ratio, (19.1 ± 0.9) nm in the thickness and (6.5 ± 1.6) nm in the roughness. The thickness of salivary film was SMSLS [(21.84 ± 1.25) nm] > WS[(17.91 ± 1.35) nm] > PS [(14.30 ± 1.03 nm) (P < 0.05). The shear elastic modulus of salivary film was PS [(0.61 ± 0.01) MPa] > SMSLS [(0.31 ± 0.09) MPa] and WS [(0.25 ± 0.03) MPa] (P < 0.05). The trend of the shear viscosity was opposite to one of thickness. CONCLUSIONS: The characteristics of saliva adsorption on HA surface suggest that the thicker, softer and more hydrated properties for the SMSLS and WS films are likely to afford a stronger lubrication to protect oral surfaces from wear and dehydration. The viscoelasticity of the PS film is probably related to the retention covering the oral cavity.
Assuntos
Durapatita/química , Glândula Parótida/metabolismo , Saliva/química , Glândula Sublingual/metabolismo , Glândula Submandibular/metabolismo , Adsorção , Adulto , Feminino , Humanos , Masculino , Microscopia de Força Atômica , Espectroscopia Fotoeletrônica , Técnicas de Microbalança de Cristal de Quartzo , Propriedades de Superfície , Viscosidade , Adulto JovemRESUMO
OBJECTIVE: The aim of the present study was to assess the null hypothesis that there are no differences of affinity between pigments and human whole saliva (WS), and the affinity is not influenced by the functional groups of pigments, temperatures, pH values, and salt concentrations. METHODS: The affinity constants of interactions between WS and theaflavin (TF)/curcumin (Cur)/cyanidin (Cy) were determined by surface plasmon resonance (SPR) and fluorescence quenching. Mass-uptake at various temperatures, pH values, and salt concentrations was also carried out. RESULTS: The order of affinity of the pigments binding to WS is TF>Cur>Cy. A large number of complexes and precipitations of pigments/proteins were formed through a quick, strong, and almost irreversible binding process. The mass-uptake of pigments was affected not only by the functional groups, but also by molecular weight of pigments, temperatures, pH values, and salt concentrations. CONCLUSION: The complex of pigments may easily and rapidly deposit onto the WS film, and are difficult to remove from the WS surface. However, the complex of pigments can be reduced by properly regulating the physicochemical conditions, such as temperatures, pH values, and salt concentrations.