| 查看: 394 | 回复: 9 | |||
| 当前主题已经存档。 | |||
| 当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖 | |||
[交流]
求专业的英语翻译，不要机译的！【有效期至2009年1月2日】
|
|||
|
Biodegradable block copolymers Abstract :Recently, block copolymers have got tremendous impetus on the ongoing research in the area of drug delivery technology, due to their capability to provide a biomaterial having a broad range of amphiphilic characteristics, as well as targeting the drugs to specific site. This article is an attempt to review applications of block copolymers in surface modification, drug targeting, nano and microparticles, hydrogels, micelles etc. The physicochemical properties of block copolymers and various synthetic routes for block copolymers are also discussed. Introduction Biodegradable polymers are the youngest members of the materials family with increasing applications in pharmaceutical, medical and biomedical engineering [1–5]. Biodegradable polymers are not limited to release of drugs, peptides or proteins at the characteristic rates and specific site target, but are also extended to medical devices [6] and wound dressing [7], as well as for fabricating scaffold in tissue engineering [8,9]. To meet these demands, biodegradable block copolymers have been found as promising biomaterials by virtue of their ability to manipulate their amphiphilic behavior, mechanical and physical properties by adjusting the ratio of the constituting block or adding new blocks of desired properties. The recent developments in this field are the subject of this review, which addresses the types of biodegradable block copolymers, synthetic routes, properties and their uses as different carriers for delivery of various drugs, peptide and proteins, as targeted agents for target specific delivery. D egradation of and drug release from a novel 2,2-bis(2-oxazoline) linked poly(lactic acid) polymer Abstract The degradation rate of poly(lactic acid) (PLA) is typically modified by copolymerization of the glycolide with lactide. In the present study, the degradation rate of PDLLA was modified by a novel linking of PLA with 2,29-bis(2-oxazoline). This modification resulted in formation of a more rapidly degrading poly(ester amide) (PEA) for controlled drug release. The hydrolytic degradation of PDLLA and PEA films was studied in PBS (pH 7.4, USP XXIV, 37 8C); the resulting decrease in molecular weight was determined by size exclusion chromatography and the weight loss of films was measured. Drug releases of guaifenesin (mw 198.2), timolol (mw 332.4), sodium salicylate (mw 160.1) and FITC–dextran (mw 4400) from PDLLA and PEA films and microspheres were examined in PBS (pH 7.4, 37 8C). The degradation rate of PEA was substantially greater than that of PDLLA. The release profiles of all small model drugs (mw ,332.4) from PDLLA films were biphasic or triphasic, while the release profiles of small model drugs from PEA films varied extensively. Due to the faster weight loss of PEA, FITC–dextran (mw 4400) was released substantially more rapidly from PEA microspheres than from PDLLA microspheres. In conclusion, all model drugs, except guaifenesin, were released faster from PEA preparations than from PDLLA preparations. Conclusion In conclusion,the addition of 2,29-bis(2-oxazoline) as a chain extender to PLA increased the hydrolytic degradation rate of the polymer.The release profiles of all small model drugs from PDLLA films were biphasic or triphasic, while release profiles of small model drugs from PEA films varied extensively.In particular,PEA enhanced the release of a macromolecule from microspheres due to the faster degradation rate of PEA.The present results suggest that PEA provides an alternative to existing biodegradable lactic acid-based polymers for controlled drug delivery. [ Last edited by zzgyb on 2009-1-17 at 09:18 ] |
回复此楼» 猜你喜欢
22408 312求调剂
已经有26人回复
-
收到复试调剂但是去不了
已经有8人回复
-
260求调剂
已经有5人回复
-
急需调剂
已经有10人回复
-
申博/考博
已经有4人回复
-
化工学硕294分，求导师收留
已经有37人回复
-
求调剂
已经有11人回复
-
一志愿华中农业071010，320求调剂
已经有19人回复
-
304求调剂
已经有7人回复
-
求博导｜生物质基多孔碳/超级电容方向，已有相关成果，寻能源材料/碳材料方向老师
已经有3人回复
人在旅途2006
金虫 (著名写手)
- 应助: 1 (幼儿园)
- 金币: 1170.9
- 帖子: 1609
- 在线: 10.8小时
- 虫号: 441073
- 注册: 2007-10-27
- 性别: GG
- 专业: 无机材料化学
7楼2009-01-01 16:25:49
2楼2008-12-31 11:04:11
高锰钢
木虫 (正式写手)
- 博学EPI: 1
- 应助: 0 (幼儿园)
- 金币: 2180.3
- 散金: 13
- 红花: 3
- 帖子: 393
- 在线: 109.4小时
- 虫号: 277589
- 注册: 2006-09-09
- 性别: GG
- 专业: 金属材料的力学行为
4楼2008-12-31 23:58:08
rockingyouth
捐助贵宾 (正式写手)
- 应助: 8 (幼儿园)
- 金币: 59.1
- 散金: 16
- 红花: 2
- 帖子: 519
- 在线: 203.6小时
- 虫号: 160833
- 注册: 2006-01-09
- 性别: GG
- 专业: 有机合成
5楼2009-01-01 10:49:02
20