RESUMO
A facile method for in situ fabrication of three-dimensional gold nanoparticle micropatterns in a cell-resistant polyethylene glycol hydrogel has been developed by combining photochemical synthesis of gold nanoparticles with photolithography technology. The gold nanoparticle micropatterns were further bio-modified with cell integrated polypeptide NcysBRGD based on a gold-thiol bond to improve cell behaviors. Primary cell tests showed that NcysBRGD can enhance cell adhesion very well on the surface of gold nanoparticle micropatterns.
Assuntos
Ouro/química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Nanopartículas Metálicas/química , Peptídeos/química , Sequência de Aminoácidos , Materiais Biocompatíveis/química , Adesão Celular , Desenho de Equipamento , Células HeLa , Humanos , Nanopartículas Metálicas/ultraestrutura , Microtecnologia , Dados de Sequência Molecular , Compostos de Sulfidrila/química , Análise Serial de Tecidos/instrumentaçãoRESUMO
In this study, silica coated Au nanospheres (Au@SiO2) were prepared by a reverse microemulsion method; subsequently, a layer of fluorescent quantum dots (QDs) were adsorbed onto it and then it was coated with silica again. After modifying with PVP, the composite silica coated gold nanosphere and quantum dots nanoparticle (Au@SiO2-QDs/SiO2-PVP) was obtained. This composite structure contained Au and QDs, and it could be used for contrast-enhanced X-ray CT imaging and fluorescence imaging. Characterization showed that the composite nanoparticle had good dispersity, a high fluorescence intensity and a good effect of X-ray absorption, and it was suitable for using as a bimodal imaging probe.
Assuntos
Corantes Fluorescentes/química , Ouro/química , Nanopartículas/química , Pontos Quânticos/química , Dióxido de Silício/química , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Meios de Contraste/química , Meios de Contraste/toxicidade , Diatrizoato de Meglumina/química , Diatrizoato de Meglumina/toxicidade , Emulsões , Corantes Fluorescentes/toxicidade , Ouro/toxicidade , Camundongos , Nanopartículas/toxicidade , Nanopartículas/ultraestrutura , Imagem Óptica , Povidona/química , Pontos Quânticos/toxicidade , Dióxido de Silício/toxicidade , Espectroscopia de Infravermelho com Transformada de Fourier , Tomografia Computadorizada por Raios XRESUMO
This work investigated the suitability of lipid carriers as potential encapsulation method to improve the physical and chemical stability of microalgae oil high in docosahexaenoic acid (DHA). Lipid carriers with various oil contents were successfully prepared by a microfluidization method using stearic acid as solid lipid, microalgae oil as liquid lipid, and poloxamer 188 as surfactant. Results show that the mean particle diameter of the lipid carriers was in the range of 300 to 350 nm with the polydispersity index below 0.2. The lipid carriers were found to have spherical shape when examined under the transmission electron microscope. Data from the encapsulation efficiency and loading capacity indicate high distribution of microalgae oil throughout the lipid carriers and good physical stability as reflected by the particle size and size distribution during storage. Furthermore, the lower DPPH scavenging activity of lipid carriers compared with that of free microalgae oil suggests better chemical stability of microalgae oil encapsulated in lipid carriers. The addition of microalgae oil into lipid phase could disturb the crystalline order and form lattice defects to enable encapsulation of DHA as revealed by the results from differential scanning calorimetery. Current results suggest that this type of novel lipid carriers could be an efficient and promising carrier system for delivery of microalgae oil.
Assuntos
Aditivos Alimentares/química , Tecnologia de Alimentos , Microalgas/química , Nanopartículas/química , Óleos/química , Ácidos Esteáricos/química , Tensoativos/química , Varredura Diferencial de Calorimetria , Fenômenos Químicos , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácidos Docosa-Hexaenoicos/química , Alimentos Fortificados , Sequestradores de Radicais Livres/química , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Nanopartículas/ultraestrutura , Tamanho da Partícula , Poloxâmero/química , Propriedades de Superfície , Temperatura , Fatores de TempoRESUMO
A new type of multifunctional quantum dot (QD)-polypeptide hybrid nanogel with targeted imaging and drug delivery properties has been developed by metal-affinity driven self-assembly between artificial polypeptides and CdSe-ZnS core-shell QDs. On the surface of QDs, a tunable sandwich-like microstructure consisting of two hydrophobic layers and one hydrophilic layer between them was verified by capillary electrophoresis, transmission electron microscopy, and dynamic light scattering measurements. Hydrophobic and hydrophilic drugs can be simultaneously loaded in a QD-polypeptide nanogel. In vitro drug release of drug-loaded QD-polypeptide nanogels varies strongly with temperature, pH, and competitors. A drug-loaded QD-polypeptide nanogel with an arginine-glycine-aspartic acid (RGD) motif exhibited efficient receptor-mediated endocytosis in αvß3 overexpressing HeLa cells but not in the control MCF-7 cells as analyzed by confocal microscopy and flow cytometry. In contrast, non-targeted QD-polypeptide nanogels revealed minimal binding and uptake in HeLa cells. Compared with the original QDs, the QD-polypeptide nanogels showed lower in vitro cytotoxicity for both HeLa cells and NIH 3T3 cells. Furthermore, the cytotoxicity of the targeted QD-polypeptide nanogel was lower for normal NIH 3T3 cells than that for HeLa cancer cells. These results demonstrate that the integration of imaging and drug delivery functions in a single QD-polypeptide nanogel has the potential for application in cancer diagnosis, imaging, and therapy.