文献汇报

1. 文献汇报 王宇瀛 2010.7.7

2. Implants 抗癌体内植入剂 药用辅料主要为生物相容性好可降解吸收的高分子多聚物 药用辅料+抗癌有效成分 • 肿瘤局部放置不仅能够降低抗癌药物的全身毒性反应，同时还能选择性地提高肿瘤局部的药物浓度，增强化疗药物及放射治疗等非手术疗法的治疗效果。 抗癌药物增效剂选自铂类化合物、紫杉醇类抗癌药物和植物生物碱之一或组合 抑制肿瘤细胞内的DNA修复功能 降低肿瘤细胞对抗癌药物的耐受性

3. Glioma Implants Failure Materials Submicron/nanoscale Microspheres Micro-porous Microfiber Microspheres,microparticles,discs Films

4. Films

5. Materials and Methods • Materials : Poly(l-lactide) (PLLA); D--Tocopheryl polyethylene glycol 1000 succinate(TPGS); Paclitaxel • Preparation of paclitaxel-loaded PLLA and PLLA/TPGS films • Morphology: FESEM • DSC • Tensile testing • In vitro drug release

6. Results：Morphology biphasic honeycomb surface Fig. 1. FESEM images of the paclitaxel-loaded PLLA/TPGS films of PLLA:TPGS ratio 100:0 (the pure PLLA film); 95:5, 90:10 and 85:15, respectively.

7. Results：DSC 5% and 10% of TPGS did not exhibit significant influence on the crystallization of the PLLA, while a larger amount of TPGS (15%) showed a significant negative influence causing a pronounced decrease of Hm from 42.1 for PLLA/TPGS 100/0 to 33.2 J/g for the PLLA/TPGS 85/15. 93.6℃ PLLA 52℃ 172.6℃ 81.4 ℃ 168.9℃ there was no such a peak detected, indicating that paclitaxel was molecularly or amorphously distributed in the films. Fig. 2. DSC thermograms of the paclitaxel-loaded PLLA and PLLA/TPGS films.

8. Results：Tensile testing PLLA /TPGS膜在断裂前表现出塑性形变——韧性 Fig. 3. Tensile stress–strain curves of the paclitaxel- loaded PLLA and PLLA/TPGS films.

9. Results：Tensile testing Tensile strength was expressed as maximum load/(thickness×width). 之前文献报道：Drug particles 可塑剂 因此此研究选同样的载药量

10. Results：In vitro drug release 蜂窝结构增大了暴露面积 Fig. 4. In vitro drug release profiles of paclitaxel from the PLLA and PLLA/TPGS films.

11. Conclusion • PLLA/TPGS film exhibited a biphasic honeycomb structure • Tensile testing of the PLLA/TPGS films exhibited a much higher flexibility than the PLLA film • Such a honeycomb-patterned PLLA/TPGS film could have better performance than the PLLA film as implants for localized drug delivery

12. Microspheres,microparticles,discs

13. Materials and Methods • Microspheres • Microparticles • discs---spray dirier, press, d=5mm • Paclitaxel-PLGA(50:50) • Etanidazole(依他硝唑，抗寄生虫)-PLGA（65:35） 1.E-disc——ultrasonication, spray dry, freeze-dry, compression 2.P-disc/P-microspheres: 5%PEG+95%PLGA+1%drug——ultrasonication 3.EHDA(直流电雾化)制备microparticles: drug loading 10% / 20% C6 subcutaneous in BALB/c nude mice Discs in tumor, microspheres around/ microparticles inject twice

14. Results and Discussion • The four treatments • Etanidazole released from implanted discs with irradiation • Paclitaxel released from spray-dried microspheres • Paclitaxel released from EHDA-fabricated microparticles (iv) Paclitaxel spray-dried discs

15. Etanidazole released from implanted discs with irradiation Placebo control 1.0mg E d9 0.5mg E d9 Secondary control 1.0mg E d6 0.5mg E d6

16. Paclitaxel released from spray-dried microspheres 0.5mg P 9d Placebo control 1.0mg P 9d 0.5mg P 6d 1.0mg P 6d

17. Paclitaxel released from EHDA-fabricated microparticles Placebo control 10% DL(0.5mg P) 1.0mg Commercial Taxol 20%DL(1.0mg P) The cytotoxicity of the microparticles

18. Paclitaxel spray-dried discs 提高载药量（15%，25%，40%）后，除对照组，均无显著差异 Relocate the discs (15%) on the contralateral flank

19. Comparison between treatments Placebo control 1% E discs 15% P discs 20% P microparticles 1% P moctopheres microparticles and microspheres which have an initial burst over the first 2 days before a linear release, are generally more effective in tumor suppression where tumor growth is arrested by the burst and sustained by the latter linear release. This becomes evident when comparing against groups from the Paclitaxel discs, which have a much slower release rate profile.

20. Etanidazole(依他硝唑，抗寄生虫)-PLGA（65:35）-disc？？？Etanidazole(依他硝唑，抗寄生虫)-PLGA（65:35）-disc？？？

21. Microfiber

22. Results > discs, wafers Fig. 1. SEM images of electrospun fibers. (A) Paclitaxel–PLGA microfiber (MF) (bar 10 mm); (B) paclitaxel–PLGA submicrofiber (SF) (bar 2 mm).

23. Results DSC 吸热融化峰223℃ Tg50℃

24. Results Fig. 3. Degradation analysis of paclitaxel–PLGA fiber discs/sheets. (A) SEM images of different dosage forms after 60 days; (A1) microfiber disc (MFD) (bar 5 mm); (A2) submicrofiber disc (SFD); (A3) microfiber sheet (MFS) (bar 5 mm); (A4) submicrofiber sheet (SFS) (B) Gel permeation chromatograms (GPC) of MFD, SFD, MFS and SFS after 60 days. disc microfiber Sub-microfiber sheet SFS>SFD>>MFS>MFD

25. Results 矛盾 Fiber discs 接近零级释放 Fiber sheet 早期有突释现象，随后接近零级 优于Gliadel的突释情况 Fig. 4. In vitro paclitaxel release from different dosage forms. Each data point represents the average of triplicate samples and error bars represent standard deviation.

26. least highest

27. Results 皮下移植瘤C6 Fig. 6. In vivo subcutaneous tumor inhibition profiles for different treatment groups.

28. Summary • Limited implantation space • Sheets could be used in the case of a larger cavity and discs could be implanted into smaller cavities • Shortage: • Taxol1,2,3,4

29. Micro-porous

30. Production of PLGA foams and compressed disks Paclitaxel-loaded foams and compressed disks were prepared from drug-loaded PLGA microparticles obtained by spray drying

31. Results and Discussion

32. Tg analysis of PLGA foams with varying copolymer compositions Foam Tg > Pellet Tg Clearly, the CO2 induced a more oriented structure in PLGA during the foaming pro- cess, leading to the higher Tg value for the foam.

33. The interconnectivity between pores enhances water penetration and the shorter diffusion path in the polymer increases the release rate of hydrophobic molecules .

34. In vitro release

35. Super-saturation of paclitaxel in PLGA; Drug crystals may form inside the polymer matrix Diffusion Polymer swelling Polymer degradation

36. summary • 收获：

37. Microspheres

38. Mathods • Paclitaxel-loaded PLGA microspheres were fabricated using • electrohydrodynamic atomization （直流电雾化）and • entrapped by electrospray and gelation. • The physicochemical characterizations were performed • using scanning electron microscopy and differential • scanning calorimetry. • In vitro release of paclitaxel was quantified using high • performance liquid chromatography. • Cytotoxicity of the formulations was assessed by the • quantification of IC50and caspase-3 activity against C6 • glioma cells in vitro. • The formulations were tested against a subcutaneous C6 • glioma tumour in nude mice.

39. Fig. 1. Schematic for the fabrication of alginate beads entrapping PLGA-paclitaxel microspheres by electrospray dripping followed by CaCl2 gelation.

40. Results Fig. 2. (B) cross-sectional view of an alginate gel bead entrapping PLGA-paclitaxel microspheres; (C) high magnification image of b with the large arrow showing the microspheres and the small arrow pointing to the gel matrix; (D) higher magnification of the alginate matrix with the arrow showing the hydrogel（水凝胶）.

41. Results DSC

42. Results

43. Results

44. Results

45. Results

46. Results C6 皮下 nude mice

47. submicron/nanoscale

48. Background • Firstly, paclitaxel-loaded PLGA submicron-fibers (F2) was developed. • Secondly, we demonstrated a composite implant consisting of paclitaxel-PLGA microspheres entrapped in alginate hydrogel matrix (H80 and M80). • Hence, in this study, firstly, we have developed a new fiber formulation: paclitaxel-loaded PLGA nanofiber (F3) and characterized the in vitro drug release. • Secondly, four formulations (F2, F3, H80, M80) were investigated for in vivo release (in plasma) and in vivo bio-distribution/penetration in mouse brain over time. • Finally, two formulations with the desired drug penetration were tested for therapeutic efficacy in an intracranial U87 MG-luc2 glioblastoma mice model through in vivo luciferase imaging & histochemical analysis.

49. Materials and methods • Preparation of paclitaxel-loaded PLGA micro/nanofibers electrospinning technique F2: Paclitaxel-PLGA submicron-fiber ~0.93µm F3: Paclitaxel-PLGA nanofiber 102 ± 20nm Placebo fiber: same condition without the drug • Fabrication of alginate beads entrapping paclitaxel-PLGA microspheres • Physicochemical characterization of the implants • Cell culture and maintenance （U87 MG-luc2） • Animal care and maintenance • In vivo paclitaxel release into mouse plasma and bio-distribution in mouse brain • Therapeutic efficacy study in an intracranial glioblastoma xenograft model in nude mice

50. Results • Physicochemical characterization of the implants • Fig. 1. Physical and in vitro release characterization of the formulations. • Representative FESEM image of paclitaxel-loaded F3 fiber disc; • Representative scanning electron microscopy image of the cross-sectional view of an alginate gel bead entrapping PLGA-paclitaxel microspheres (H80);