RESUMO
BACKGROUND:Compared with conventional medications, drug micro-capsule system can control the release of drugs and have wel target properties and biocompatibility. The drugs can be concentrated at the focus and play an important role in clinic. OBJECTIVE:To prepare dacarbazine magnetic micro-capsules with different capsule materials and gelatin complex by coacervation, and to optimize capsule materials and preparation process. METHODS:Fe 3 O 4 RESULTS AND CONCLUSION:The solution complex coacervation method was better than the emulsion coacervation method. As for the solution complex coacervation method, the optimal capsule material was gelatin-sodium alginate, with drug embedding rate 37.90%, the yield rate 72.31%, and the average magnetization intensity 8.53 emu/g. The second material was gelatin-chitosan. As a capsule material, the gelatin was better than chitosan with single coagulation method. Drug embedding rate was 51.58%, the yield rate was 64.50%, and the average magnetization was 6.93 emu/g. Single coagulation method was better than coacervation method. complex coacervation, we prepared the gelatin-Arabic gum magnetic micro-capsule, gelatin-sodium alginate magnetic micro-capsules, gelatin-sodium carboxymethyl cel ulose magnetic micro-capsules, and gelatin-chitosan magnetic micro-capsules. With the emulsion complex coacervation method, we further prepared the gelatin-Arabic gum magnetic micro-capsule, gelatin-sodium alginate magnetic micro-capsules, gelatin-sodium carboxymethyl cel ulose magnetic micro-capsules, and gelatin-chitosan magnetic micro-capsules. The magnetic gelatin micro-capsules and magnetic chitosan micro-capsules were prepared with single coagulation method. The micro-capsules were determined for the embedding rate, the magnetic susceptibility, the micro-capsule size and the release performance, to define the optimal preparation technology of dacarbazine magnetic micro-capsules.
RESUMO
Histopathological examination of testes is important in assessing spermatogenesis and testicular function. Modified Davidson's fluid (mDF) has been proposed as a superior substitute for Bouin's fluid (BF) for fixation of adult animal testes. Besides, 4% paraformaldehyde (PFA) has been commonly used to fix testes with convenience. We compared the morphology of the rat testis fixed in 4% PFA, mDF, or BF using hematoxylin and eosin (HE)-stained sections. Fixation in 4% PFA resulted in obvious tissue shrinkage artifacts, especially between seminiferous epithelium cells. Shrinkage artifacts were also observed in the central area of the testes fixed in BF. Use of mDF did not cause shrinkage artifacts between seminiferous tubules, though a small amount can be observed in seminiferous tubules between germ cells. Clarity of nuclear detail in testes fixed in mDF and BF is better compared to 4% PFA. Our study demonstrated that fixation in mDF provided better morphologic details in the rat testis as compared with 4% PFA and BF.