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1.
Int J Biol Macromol ; 190: 940-959, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34478798

RESUMO

Among the diverse nanomaterials, polymer-based nanocomposites are gained more attention due to their high efficacy, target biological activities, biodegradability and biocompatibility-gum acacia (GA) - a polymer obtained from acacia trees-is considering the multifunctional nanocomposite synthesis. Distinctive Physico-chemical and biocompatibility properties of gum acacia are utilised to prepare a highly stable, biologically active, eco-friendly Nanocomposite. In this current investigation, gum acacia - poly ethylene glycol grafted iron oxide nanocomposite (GA-PEG-IONC) was synthesised by in situ green science principles. The synthesised Nanocomposite was evaluated against the molecular mechanism of urinary tract pathogenic bacterial strains and prostate cancer cells (Pc 3). Nanocomposite prepared in this examination exhibited notable structural, functional stability with nanoarchitecture which was affirmed by Fourier transform infrared spectroscopy (FTIR), electron microscopic studies, atomic force microscopy (AFM), vibrating sample magnetometric analysis (VSM) and X-ray diffraction (XRD), Synthesised Nanocomposite brought about notable antibacterial activity against urinary tract pathogenic strains by recording potential inhibitory effect on the expression of Las R gene. Inhibition of Las R gene expression reduced notable effect on biofilm development. Anticancer activity against prostate cancer cells (Pc3) was investigated by measurement of HOXB13 gene expression level. Inhibition of HOXB13 gene expression by the IONC brought about structural, functional changes. HOXB13 gene expression inhibition reveals a remarkable cytotoxic effect by recording decreased cell viability. Morphometric analysis by phase-contrast and DAPI fluorescence staining demonstrates that the Nanocomposite prompted cell morphology anomalies or apoptotic changes. Nanocomposite treatment brought about a good sign of Apoptosis by recording enhanced caspase 3 and 9 activities, DNA fragmentation and elevated reactive oxygen species generation (ROS). Hemocompatibility studies were carried out to determine the biocompatibility of the Nanocomposite. Spectrophotometric estimation of plasma haemoglobin, microscopic examination of whole blood cells shows the Nanocomposite was not inciting any indication of toxicity. These findings infer that IONC synthesised in the present study is the promising contender for a broad scope of biomedical applications, especially as an antibacterial and anticancer agent.


Assuntos
Compostos Férricos/química , Genes vpr , Goma Arábica/química , Proteínas de Homeodomínio/genética , Nanocompostos/química , Polietilenoglicóis/química , Neoplasias da Próstata/genética , Pseudomonas aeruginosa/genética , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Biofilmes/efeitos dos fármacos , Caspase 3/metabolismo , Catéteres , Fragmentação do DNA/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Química Verde , Proteínas de Homeodomínio/metabolismo , Humanos , Masculino , Testes de Sensibilidade Microbiana , Nanocompostos/ultraestrutura , Células PC-3 , Filogenia , Pseudomonas aeruginosa/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
2.
Biotechnol Bioeng ; 112(2): 393-404, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25116006

RESUMO

In this study, the distribution of oxygen and glucose was evaluated along with consumption by hepatocytes using three different approaches. The methods include (i) Computational Fluid Dynamics (CFD) simulation, (ii) residence time distribution (RTD) analysis using a step-input coupled with segregation model or dispersion model, and (iii) experimentally determined consumption by HepG2 cells in an open-loop. Chitosan-gelatin (CG) scaffolds prepared by freeze-drying and polycaprolactone (PCL) scaffolds prepared by salt leaching technique were utilized for RTD analyses. The scaffold characteristics were used in CFD simulations i.e. Brinkman's equation for flow through porous medium, structural mechanics for fluid induced scaffold deformation, and advection-diffusion equation coupled with Michaelis-Menten rate equations for nutrient consumption. With the assumption that each hepatocyte behaves like a micro-batch reactor within the scaffold, segregation model was combined with RTD to determine exit concentration. A flow rate of 1 mL/min was used in the bioreactor seeded with 0.6 × 10(6) HepG2 cells/cm(3) on CG scaffolds and oxygen consumption was measured using two flow-through electrodes located at the inlet and outlet. Glucose in the spent growth medium was also analyzed. RTD results showed distribution of nutrients to depend on the surface characteristics of scaffolds. Comparisons of outlet oxygen concentrations between the simulation results, and experimental results showed good agreement with the dispersion model. Outlet oxygen concentrations from segregation model predictions were lower. Doubling the cell density showed a need for increasing the flow rate in CFD simulations. This integrated approach provide a useful strategy in designing bioreactors and monitoring tissue regeneration.


Assuntos
Reatores Biológicos , Glucose/metabolismo , Oxigênio/metabolismo , Alicerces Teciduais/química , Proliferação de Células , Quitosana/química , Gelatina/química , Células Hep G2 , Humanos , Poliésteres/química , Porosidade , Fatores de Tempo
3.
Ann Biomed Eng ; 42(6): 1319-30, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24719051

RESUMO

The goal of this study was to better understand how analytical permeability models based on scaffold architecture can facilitate a non-invasive technique to real time monitoring of pressure drop in bioreactors. In particular, we evaluated the permeability equations for electrospun and freeze dried scaffolds via pressure drop comparison in an axial-flow bioreactor using computational fluid dynamic (CFD) and experimentation. The polycaprolactone-cellulose acetate fibers obtained by co-axial electrospinning technique and Chitosan-Gelatin scaffolds prepared using freeze-drying techniques were utilized. Initially, the structural properties (fiber size, pore size and porosity) and mechanical properties (elastic modulus and Poisson's ratio) of scaffolds in phosphate buffered saline at 37 °C were evaluated. The CFD simulations were performed by coupling fluid flow, described by Brinkman equation, with structural mechanics using a moving mesh. The experimentally obtained pressure drop values for both 1 mm thick and 2 mm thick scaffolds agreed with simulation results. To evaluate the effect of permeability and elastic modulus on pressure drop, CFD predictions were extended to a broad range of permeabilities spanning synthetic scaffolds and tissues, elastic moduli, and Poisson's ratio. Results indicated an increase in pressure drop with increase in permeability. Scaffolds with higher elastic modulus performed better and the effect of Poisson's ratio was insignificant. Flow induced deformation was negligible in axial-flow bioreactor. In summary, scaffold permeabilities can be calculated using scaffold microarchitecture and can be used in non-invasive monitoring of tissue regeneration.


Assuntos
Reatores Biológicos , Modelos Biológicos , Regeneração , Alicerces Teciduais , Animais , Humanos
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