RESUMEN
OBJECTIVES: Zein nanoparticles (Zein NPs) were used as a hydroxyapatite (HA) biomineralization template to generate HA/Zein NPs. Doxorubicin hydrochloride (DOX) was loaded on HA/Zein NPs (HA/Zein-DOX NPs) to improve its pH-sensitive release, bioavailability and decrease cardiotoxicity. METHODS: HA/Zein-DOX NPs were prepared by phase separation and biomimetic mineralization method. Particle size, polydispersity index (PDI), Zeta potential, transmission electron microscope, X-ray diffraction and Fourier-transform infrared spectroscopy of HA/Zein-DOX NPs were characterized. The nanoparticles were then evaluated in vitro and in vivo. KEY FINDINGS: The small PDI and high Zeta potential demonstrated that HA/Zein-DOX NPs were a stable and homogeneous dispersed system and that HA was mineralized on Zein-DOX NPs. HA/Zein-DOX NPs showed pH-sensitive release. Compared with free DOX, HA/Zein-DOX NPs increased cellular uptake which caused 7 times higher in-vitro cytotoxicity in 4T1 cells. Pharmacokinetic experiments indicated the t1/2ß and AUC0- t of HA/Zein-DOX NPs were 2.73- and 3.12-fold higher than those of DOX solution, respectively. Tissue distribution exhibited HA/Zein-DOX NPs reduced heart toxicity with lower heart targeting efficiency (18.58%) than that of DOX solution (37.62%). CONCLUSION: In this study, HA/Zein-DOX NPs represented an antitumour drug delivery system for DOX in clinical tumour therapy with improved bioavailability and decreased cardiotoxicity.
Asunto(s)
Doxorrubicina/administración & dosificación , Portadores de Fármacos/farmacocinética , Sistemas de Liberación de Medicamentos/métodos , Durapatita/farmacocinética , Nanopartículas/química , Zeína/farmacocinética , Animales , Disponibilidad Biológica , Línea Celular , Supervivencia Celular/efectos de los fármacos , Portadores de Fármacos/química , Liberación de Fármacos , Durapatita/química , Ratones , Ratas , Ratas Sprague-Dawley , Distribución TisularRESUMEN
The separation of hazardous metals from contaminated sources is commonly achieved with ion-exchange resins. The resins have a high surface area decorated with many ion-exchange sites and thus a high sorption capacity for the analyte of interest. However, these sites are primarily accessed by diffusion which limits the throughput and quality of the separation. Reported herein is a study of monolithic polyHIPE foam columns surface-grafted with a brush of polymer containing ion-exchange functionality for the separation of Pu. It was found that the loading curves of the foam material are steeper than a similarly scaled resin-based column, and the elution profiles of the foams were narrower than the resin, generating more concentrated eluate relative to the amount of Pu loaded onto the foam columns. On a gravimetric basis, the foams had a similar or greater Pu capacity than the resin with fewer ion-exchange sites per unit mass. These characteristics are mainly due to the convective mass transport which dominates the separation in the polyHIPE materials, suggesting that these materials may be useful for more efficient hazardous metal separations.
RESUMEN
Caulobacter segnis is a unique species of Caulobacter that was initially deemed Mycoplana segnis because it was isolated from soil and appeared to share a number of features with other Mycoplana. After a 16S rDNA analysis showed that it was closely related to Caulobacter crescentus, it was reclassified C. segnis. Because the C. segnis genome sequence available in GenBank contained 126 pseudogenes, we compared the original sequencing data to the GenBank sequence and determined that many of the pseudogenes were due to sequence errors in the GenBank sequence. Consequently, we used multiple approaches to correct and reannotate the C. segnis genome sequence. In total, we deleted 247 bp, added 14 bp, and changed 8 bp resulting in 233 fewer bases in our corrected sequence. The corrected sequence contains only 15 pseudogenes compared to 126 in the original annotation. Furthermore, we found that unlike Mycoplana, C. segnis divides by fission, producing swarmer cells that have a single, polar flagellum.