폴리락타이드 스테레오 콤플렉스 형성을 이용한 주입형 하이드로젤의 합성 및 특성평가
Preparation and characterization of injectable hydrogel by stereocomplexation of 4-arm PEG-PDLA/PLLA block copolymers
- 주제(키워드) stereocomplexed hydrogel
- 발행기관 아주대학교
- 지도교수 박기동
- 발행년도 2009
- 학위수여년월 2009. 2
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 실제URI http://www.dcollection.net/handler/ajou/000000009808
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Injectable hydrogels are quite promising materials because they have the potential to minimize invasive implantation, which provide versatile fitness irrelevant to the damaged regions and facilitate the incorporation of bioactive agents or cells. In situ gel formation through stereocomplex formation is a promising candidate for injectable hydrogels. In this paper, a new series of enantiomeric 4-arm PEG-PLA block copolymers and their stereocomplexed hydrogels were prepared by bulk ring-opening polymerization of D-lactide and L-lactide, respectively, with stannous octoate as a catalyst. The prepared polymers were characterized by 1H NMR, FT IR, GPC and TGA, confirming the tailored structure and chain lengths. The swelling and degradation behavior of the hydrogels formed from a selected copolymer series are observed in different concentrations. The results showed that a larger portion of the polymers in a solution induced a slower degradation rate. The rheological behavior indicated that the prepared hydrogel underwent in situ gelation and had favorable mechanical strength. In addition, its feasibility as an injectable scaffold was evaluated using a media dependence test for cell culture. It was found that a Tris solution was more favorable for in situ gel formation than PBS and DMEM solutions. These results suggest that in situ forming hydrogel through the construction of a stereocomplex with enantiomeric 4-arm PEG-PLA copolymers was accomplished. Overall, enantiomeric 4-arm PEG-PLA copolymers are new species of stereocomplexed hydrogels that are suitable for further research into injectable hydrogels.
more목차
CONTENTS
Ⅰ. INTRODUCTION
A. Tissue Engineering
B. Polymeric Biomaterials for Tissue Engineering
1. Ideal biomaterial characteristics
2. Pores and permeation in biomaterials
3. Biodegradability
4. Material stiffness
C. Injectable Hydrogels
1. Photoinitiated crosslinking
2. Temperature sensitive systems
3. Crosslinking with addition reaction
4. Crosslinking using enzymes
D. Stereocomplex formation
1. Polylactide (PLA)
2. Stereocomplex formation between enantiomeric PLAs
E. Objectives
Ⅱ. EXPERIMENTS
A. Materials
B. Synthesis of 4-arm PEG-PLA block copolymers
C. Characterizations of the 4-arm PEG-PLA block copolymers
D. Preparation of the stereocomplexed hydrogel
E. Characterizations of the stereocomplexed hydrogel
1. Rheological analysis
2. Gel swelling behavior
Ⅲ. RESULTS AND DISCUSSIONS
A. Synthesis of the 4-arm PEG-PLA block copolymers
B. Thermal stability
C. In situ hydrogelation by stereocomplex formation
D. Rheological properties of hydrogels
E. Swelling and degradation behavior of hydrogels
F. Feasibility as injectable scaffolds
Ⅳ. CONCLUSIONS
Ⅴ. REFERENCES
