ABSTRACT
In this study, the chitosan-based release microspheres were prepared by spray drying method. Chitosan was used as the carrier material, and Panax notoginseng extract, Codonopsis extract, and Atractylodes extract (the mass ratio was 2:7:5) were active substance. The spray drying preparation process of microsphere was optimized by single factor experiment and L9 (34) orthogonal design. Drug loading (DL), particle size, and sustained release performance of microspheres were investigated. The mass fraction of chitosan was 1.5%, the mass ratio of drug to chitosan was 1:3, the inlet air temperature was 130°C, and the injection rate was 400 ml/hr. The chitosan-based microspheres prepared under the above conditions had a smooth surface, and the DL was 23.87 ± 0.93%; the average particle diameter was 10.27 ± 1.05 µm, and the encapsulation efficiency (EE) of the microspheres was 91.28 ± 1.04%. The preparation process of chitosan-based drug microsphere prepared by spray drying method was simple and stable. The prepared microspheres in this paper showed a sustained release effect in vitro.
ABSTRACT
Recently, neutrophil gelatinase-associated lipocalin (NGAL) and its cell surface receptor, NGALR, have been shown to have critical roles in the biology of various tumors. Therefore, we investigated the expression of NGAL and NGALR in tumor sections obtained from patients with gliomas, and compared these results with the clinical characteristics of the patients. Using immunohistochemical assays, the expression levels of NGAL and NGALR were found to be up-regulated in tumor tissues, and to be related to tumor grade (p < 0.001). A positive correlation between expression of the two markers was also observed in these assays (r = 0.849; p < 0.001). Overexpression of NGAL and NGALR in glioma tissues was also confirmed in western blot analysis and real-time quantitative RT-PCR assays. Furthermore, overexpression of NGAL and NGALR was found to be significantly associated with poor prognosis (p < 0.001 in each case). Multivariate analysis identified patient age, tumor grade, and expression levels of NGAL and NGALR to be independent prognostic factors. In particular, NGAL(2+)/NGALR(2+) tissues were associated with lower rates of survival (risk ratio, 1.378; 95% CI, 1.102-1.724; p = 0.005). These findings suggest that NGAL and NGALR expression are frequently up-regulated in gliomas, and are closely associated with poor clinical outcome.
