京尼平交联丝素蛋白—壳聚糖缓释微球的制备与表征

目的 研究不同浓度京尼平和不同丝素蛋白( silk fibroin, SF)与壳聚糖( chitosan, CS)比例制备的SF-CS复合微球包载和缓释牛血清白蛋白( bull serum albumin,BSA)的效能. 方法 无机乳化交联法制备SF-CS微球,取其中SF:CS=1:1比例的微球包载BSA,并与单纯的CS微球进行对比,考察微球的包载效能和缓释效能. 扫描电镜观察微球表面形态,激光粒度分析仪测定微球直径,X射线衍射、傅里叶红外光谱及热重分析对微球表征进行分析,BCA法测定微球的包封率、载药率和累积缓释率. 结果 以m(CS):m(SF)为1:0. 5和京尼平0. 1 g或0. 5 g、m(CS):m(SF)为1:1和京尼平0. 05 g或1 g、m(CS):m(SF)为1:2和京尼平0. 5 g,制备的微球形态较为规则、圆滑,粒径分布在70~150μm. 以m(CS):m(SF)为1:1和京尼平0. 05 g,按投药量10 mg、20 mg或50 mg的BSA制备微球,包封率分别为(50. 16 ± 4. 32)%、(56. 58 ± 3. 58)%和(42. 19 ± 7. 47)%,傅里叶红外光谱、X射线衍射和热重分析的结果证明SF和CS发生交联, BSA、CS和SF间没有发生任何化学反应. 投药量10 mg、20 mg和50 mg组微球缓释结果显示,第1 天分别爆释总量的(30. 79 ± 3. 43)%、(34. 41 ± 4. 46)%和(41. 75 ± 0. 96)%,21 d累积释放(75. 20 ± 2. 52)%、(79. 16 ± 4. 31)%和(89. 04 ± 4. 68)%,以同样方法制备的BSA投入量为10 mg纯CS微球,第1天爆释总量的(39. 53 ± 1. 76)%,21 d爆释(83. 57 ± 2. 33)%. 结论 SF-CS复合微球比单纯的CS微球有更佳的缓释效能,可能是一种有效的药物转运系统.

Preparation and characterization of genipin-crosslinked silk fibroin/chitosan sustained release microspheres

Objective To investigate the efficiency of different concentrations of genipin and silk fibroin ( SF):chi-tosan ( CS) ratios on the package and release of SF-CS composite microspheres. Methods Selected the microspheres with a SF:CS ratio of 1:1 to encapsulate different concentrations of bovine serum albumin ( BSA) and compared their en-capsulation efficiency and sustained-release rate with those of pure chitosan microspheres. SF-CS microspheres were pre-pared with emulsion cross-linking technique. The microspheres were observed by scanning electron microscope. Size dis-tribution was measured by a laser particle size analyzer. X-ray diffractometry ( XRD) , fourier transform infrared spectros-copy ( FTIR) and thermogravimetricanalyzer ( TGA) were used to analyze their structural characteristics. BCA method was used for determination of the drug entrapment, loading rate and cumulative release of the total drug. Results The five types of microspheres ( m ( CS): m ( SF) = 1:0. 5, 0. 1 g or 0. 5 g genipin; m ( CS):m ( SF) = 1:1, 0. 05 g or 1 g ge-nipin; m ( CS):m ( SF) = 1:2, 0. 5 g eniping) had a more spherical shape and smooth surface with particle size between 70-147 μm. The microspheres prepared with m ( CS):m ( SF) of 1:1 and 0. 05 g genipin in the presence of 10 mg, 20 mg, or 50 mg BSA of BSA burst-released ( 30. 79 ± 3. 43)%, ( 34. 41 ± 4. 46)%, or ( 41. 75 ± 0. 96)% of the en-trapped BSA on the first day, and cumulatively released ( 75. 20 ± 2. 52)%, ( 79. 16 ± 4. 31)%, and ( 89. 04 ± 4. 68)%in 21 d, respectively. The pure CS microspheres prepared in the presence of 10 mg BSA burst-released ( 39. 53 ± 1. 76)% on the first day and cumulatively released ( 83. 57 ± 2. 33)% of the total encapsulated BSA in 21 d. Conclusion The SF-CS composite microspheres had a higher sustained release rate than the pure CS microspheres and may be a better drug carrier.