TGF-beta 3 고정화된 조직재생의학용 주입형 히알루론산 하이드로젤
In situ crosslinkable hyaluronic acid based hydrogel covalently bound with TGF-beta 3 for tissue regenerative medicine
- 주제(키워드) tissue regeneration , hydrogel , TGF-beta3 , hyaluronic acid
- 발행기관 아주대학교
- 지도교수 박기동 교수님
- 발행년도 2012
- 학위수여년월 2012. 2
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 실제URI http://www.dcollection.net/handler/ajou/000000012316
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
In situ forming hydrogel have been widely studied as a cell supporting matrix and protein delivery carrier for tissue regeneration medicine. For an effective regeneration of tissue, various growth factors were used to promote new formation of tissue. In many growth factor loading tools into scaffolds, immobilization method is more effective than others because activity of growth factors was maintained within the hydrogels for a long term. Facile immobilization of growth factors in hyaluronic acid (HA) hydrogels using dual enzymes is reported in the paper. The hydrogels were formed by using horseradish peroxidase (HRP) and hydrogen peroxide (H2O2) and transforming growth factor-？3 (TGF-？3) was covalently conjugated on the hydrogels in situ using tyrosinase (Ty) without any modifications. For the preparation of hydrogels, HA was grafted with poly(ethylene glycol) (PEG), which was modified with a tyrosine. The gelation times of the HA hydrogels were ranging from 415 to 17 s and the storage moduli was dependent on the concentration of H2O2 and Ty (470-1600 Pa). A native TGF-？3 (200 ng/mL) was readily encapsulated in the HA hydrogels and 17% of the TGF-？3 was released over 1 month at the Ty concentration of 0.5 KU/mL, while the release was faster when 0.3 KU/mL of Ty was used for the encapsulation (27%). It can be suggested that the growth factors resident in the hydrogels for a long period of time may lead cells proliferating and differentiating, whereas the growth factors that are initially released from the hydrogels can induce the ingrowth of cells into the matrices. Therefore, the dual enzymatic methods as facile gel forming and loading of various native growth factors or therapeutic proteins could be highly promising for biomedical applications.
more목차
1. INTRODUCTION 1
1.1. Tissue engineering 1
1.2. Hydrogels as a biomaterial 3
1.2.1. Hyaluronic acid 5
1.2.2. Enzymatic cross-linkable hydrogels 7
1.3. Controlled release of growth factor 8
1.4. Transforming Growth Factor-beta (TGF-β3) family 9
1.5. Tyrosinase-mediated reactions 11
1.6. Objectives 14
2. EXPERIMENTAL PARTS 16
2.1. Materials 16
2.2. Synthesis of polymers 16
2.2.1. PNC-PEG-PNC conjugate 16
2.2.2. Amino PEG-tyramine (H₂N-PEG-TA) conjugate 17
2.2.3. Hyaluronic acid-PEG-tyramine (HAPT) conjugate 17
2.3. The gelation time of HAPT hydrogels 18
2.4. Rheological measurements of HAPT hydrogels 18
2.5. In situ immobilization of TGF-β3 in HAPT hydrogels and release study 19
3. RESULTS AND DISCUSSION 20
3.1. Synthesis and characterization of polymers 20
3.1.1. ¹H NMR spectrum of PNC-PEG-PNC 20
3.1.2. Characterizations of H₂N-PEG-TA and HAPT conjugates 21
3.2. Preparation of in situ HAPT 22
3.3. Gelation time of HAPT hydrogels 22
3.4. Rheological measurements 24
3.4.1. Effects of H₂O₂ concentration of storage modulus 24
3.4.2. Effects of Ty concentration of storage modulus 25
3.5. In vitro release behavior of TGF-β3 from HAPT hydrogels 27
4. CONCLUSIONS 29
5. REFERENCES 30
