Catalytic Synthesis and Characterization of Biodegradable ...

More documents

Recommendations

Info

Chapter 1 PANI fibers. 169 These devices have promising biomedical applications as electrical-responsive actuators, such as micropumps and valves for labs-on-a-chip, 170 steerable catheters for minimally invasive surgery, 171 blood vessel connectors (Figure. 1.5.19), 172 and microvalves for urinary incontinence. Figure. 1.5.18 (A) When current is applied, the left PPy film acts as anode and swells by the entry of the hydrated counter ions. Simultaneously, the right film acts as cathode and contracts by the expulsion of the counter ions. These volume changes and the constant length of the non-conducting film promote the movement of the triple layer device. (B) By changing the direction of current the movement takes place in the opposite direction. 167 Scavenging of free radicals is a protective response in biological system, which may afford against various diseases, such as cardio-vascular diseases and cancer. The potential role of PANi 129 as antioxidants in rubber mixes has already been considered, and the PANi was demonstrated to be efficient in slowing down the rate of oxidation. And recently the electroactive polymers were also used in biological applications. 173 These polymers such as PANi and PPy in their neutral form can eliminate 2 ~ 4 free radicals per monomer unit. The ability of these materials to scavenge free radicals is attributed to their oxidation activity and has no relationship with electrical stimulation. These materials have potential biomedical applications in tissues experiencing high oxidative stress. ‐ 38 ‐
- 39 - Polymerization and Applications of Biodegradable Polyesters Figure. 1.5.19 PPy blood vessel connector insertion surgery. (A, B) A PPy-Au bilayer device in the reduced state is curled into a roll that is inserted half-way into one of the ends of the severed blood vessel. (C, D) The other half of the device is inserted inside the other end of the vessel and the bilayer expands a few minutes after PPy is oxidized. The PPy tube holds the two parts of the blood vessel together during healing, which replaces sutures. The connector is non-thrombogenic and very thin to avoid restricting the space inside the blood vessel. 172 Although many kinds of electroactive polymers (most of them are CPs) have been explored for biomedical application, little attentions have been paid on the biologically active radical polymers. Therefore, in this thesis we prepared novel TEMPO-contained electroacitve polymers and investigated the feasibility of them in biomedical application. This exploration was creative and important for developing novel electroacitve biomaterials. 1.6 Radicals Polymers As a stable radical, 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) has applications throughout chemistry and biochemistry. For example, it was widely used as a radical trapping, as a spinning-labeled reagent in biological systems, as a reagent in organic synthesis, and as a mediator in controlled free radical polymerization. 174-177 TEMPO is prepared by the oxidation of 2,2,6,6-tetramethylpiperidine (TEMP). It was well known that the nitroxide free radicals could participate in one-electron redox reaction in acidic medium to yield relatively stable
Page 1 and 2: Catalytic Synthesis and Characteriz
Page 3 and 4: Preface Biodegradable polyesters ha
Page 5 and 6: Chapter 3 Polymerization of Lactic
Page 7 and 8: Chapter 1 Polymerization and Applic
Page 9 and 10: - 3 - Polymerization and Applicatio
Page 13 and 14: 1.2.2 Aluminum Catalysts - 7 - Poly
Page 17 and 18: 1.3 Polylactide 1.3.1 Introduction
Page 19 and 20: - 13 - Polymerization and Applicati
Page 21 and 22: 1.3.4 Application of PLA Figure 1.3
Page 27 and 28: 1.5.1.4 Polyaniline (PANi) - 21 - P
Page 43: - 37 - Polymerization and Applicati
Page 47 and 48: 1.6.1 Radical Polymers for Organic
Page 51 and 52: initialization of the device by app
Page 55 and 56: 1.6.2.4 Others - 49 - Polymerizatio
Page 63 and 64: 182. R. B. Weller, J. Invest. Derma
Page 65 and 66: Chapter 2 Synthesis and Electrochem
Page 67 and 68: Synthesis and Electrochemistry of S
Page 79: Synthesis and Electrochemistry of S
Page 84 and 85: Chapter 3 3.1 Introduction Poly(lac
Page 86 and 87: Chapter 3 polydispersity index (PDI
Page 88 and 89: Chapter 3 aluminum based complexes
Page 90 and 91: Chapter 3 3.5 Conclusions Co(III) c
Page 92 and 93: Chapter 3 22. Z. H. Tang, X. S. Che
Page 94 and 95:
Chapter 4 4.1 Introduction Stimulus
Page 96 and 97:
Chapter 4 the proton of methenyl gr
Page 98 and 99:
Chapter 4 attributed to the amide g
Page 100 and 101:
Chapter 4 4.4 Thermal Properties Th
Page 102 and 103:
Chapter 4 Figure 4.8 MTT assay for
Page 104 and 105:
Chapter 4 The 1 H NMR and 13 C NMR
Page 106 and 107:
Chapter 4 Cell viability (%) = (Asa
Page 109 and 110:
Chapter 5 Synthesis of Triblock Cop
Page 111 and 112:
5.2 Synthesis of Triblock Copolymer
Page 113 and 114:
Sample Table 1. Feed and result com
Page 115 and 116:
= 25 μm. B: MTT assay for the cyto
Page 117 and 118:
‐ 109 ‐ Synthesis of Triblock C
Page 119:
‐ 111 ‐ Synthesis of Triblock C
Page 124 and 125:
Chapter 6 6.1 Introduction Since th
Page 126 and 127:
Chapter 6 6.3 Synthesis of MPEG-b-P
Page 128 and 129:
Chapter 6 used to characterize the
Page 130 and 131:
Chapter 6 Figure 6.6 Cyclic voltamm
Page 132 and 133:
Chapter 6 vivo cytotoxicity was als
Page 134 and 135:
Chapter 6 NMR. Characterization of
Page 136 and 137:
Chapter 6 CO2 for 24 h. RSC96 cells
Page 141 and 142:
Chapter 7 Conclusion and Future Pro
Page 143 and 144:
‐ 131 ‐ Conclusion and Future P
Page 145 and 146:
‐ 133 ‐ Conclusion and Future P
Page 147 and 148:
13. Xuan Pang, Xuesi Chen, Xiuli Zh
Page 149:
Acknowledgments The present thesis
show all

Catalytic Synthesis and Characterization of Biodegradable ...

Create successful ePaper yourself

Delete template?

Save as template?