Li P.,Beihang University |
Li P.,Beijing Key Laboratory For Optimal Des And Eval Technology Of Implantable And Interventional Med Devices |
Li K.,Beihang University |
Li K.,Beijing Key Laboratory For Optimal Des And Eval Technology Of Implantable And Interventional Med Devices |
And 5 more authors.
RSC Advances | Year: 2016
Magnetic-fluorescent bifunctional microspheres as a drug delivery system (DDS) possess magnetic targeting and fluorescent tracing capabilities simultaneously. The fluorescent intensity of DDS is weakened by magnetic particles, however; the fluorescent tracing of a drug cannot be achieved completely due to the separation of drug and fluorescent materials. In this study, we prepared a benzimidazole (Bim) fluorescent-labeling drug with dual rare earth (RE) ions as EuLa3(Bim)12 to increase the accuracy of tracing and fluorescent intensity. The electrospraying method with dual parallel spinnerets was used to produce Janus polylactide-co-glycolide (PLGA) microspheres with Fe3O4 nanoparticles and the fluorescent-labeling drug EuLa3(Bim)12 in separate chambers. Analysis results revealed that [PLGA/EuLa3(Bim)12]//[PLGA/Fe3O4] Janus microspheres simultaneously possessed superior magnetic and fluorescent properties. Moreover, the [PLGA/EuLa3(Bim)12]//[PLGA/Fe3O4] Janus microspheres showed higher fluorescent intensity than that of PLGA/EuLa3(Bim)12/Fe3O4 composite microspheres. © The Royal Society of Chemistry 2016.
Guo M.,Beihang University |
Guo M.,Beijing Key Laboratory For Optimal Des And Eval Technology Of Implantable And Interventional Med Devices |
Chu Z.,Beihang University |
Chu Z.,Beijing Key Laboratory For Optimal Des And Eval Technology Of Implantable And Interventional Med Devices |
And 11 more authors.
Polymer Degradation and Stability | Year: 2016
The inhomogeneous stress distribution of biodegradable stents after implantation affects the local degradation rate of the stents, leading to stress concentration and hence stent fracture. The quantitative relationship between the tensile stress and degradation rate of stent polymer is first investigated in this work. To implement the study, an in vitro degradation of poly(l-lactide-co-glycolide) (PLGA) membranes was incubated in deionized water under different applied tensile stress levels from 0.1 MPa to 0.5 MPa. By a special designed device, the tensile stress level can be maintained constant during degradation. The mass loss and mechanical properties of the membranes during the degradation were sampled each week until the membranes broke. The experimental results showed that over a range of tensile stress, higher tensile stress might lead to quicker loss of mechanical properties. Specifically, remarkable decreases of elastic modulus and tensile strength in 0.5 MPa group were observed. As the magnitude of tensile stress increased, more mass loss was observed in the loaded groups. In conclusion, the mass loss rate and mechanical properties of PLGA was sensitive to the tensile stress level during the in vitro degradation. The load dependency of our data demonstrates the importance of quantifying the effects of tensile stress on the degradation of biodegradable polymers. Moreover, this quantification model could be used as a prediction tool for the optimization of biodegradable polymer stents. © 2015 Elsevier Ltd. All rights reserved.