碩士 / 國立臺北科技大學 / 化學工程與生物科技系化學工程碩士班 / 106 / The 3D printing technology can make three-dimensional porous scaffolds that are connected to each other, which is beneficial to cell growth, nutrient transport and metabolite elimination. Sodium alginate is a natural polymer that is soluble in water and non-cytotoxic. It is soft, permeable, not easy to stick to wounds, easy to remove, absorbs wound exudate and blood, accelerates blood clotting and facilitates tissue repair. Chitosan is also a commonly used natural substrate with a unique property of positively charged ions on the surface, which can attract red blood cells and platelets to achieve rapid hemostasis, which is beneficial to wound healing. The 3D scaffold made of sodium alginate has poor mechanical properties and is less able to delay the release of the drug. Therefore, the chitosan is coated on the alginate fiber by means of ion crosslinking, thereby improving the mechanical properties of the 3D scaffold and delaying the drug release.
In this experiment, a porous scaffold was prepared by 3D printing. The experiment was divided into a control group and an experimental group. The control group was cross-linked with alginic acid and calcium chloride to make a scaffold. The experimental group used alginic acid and chitosan mix with calcium chloride is crosslinked to make a scaffold coated with chitosan. Three kinds of antibiotics (Ampicillin, Tetracycline Hydrochloride, Chloramphenicol) with similar molecular weights were used as carrier drugs in drug delivery systems to study their release properties(drug load, drug release rate) and antibacterial ability (inhibition zone), and the chitosan content, mechanical strength, degradation rate, cell activity test were discussed.
Using three different methods, proved that the chitosan was successfully coated on the sodium alginate scaffold. First, the experimental results show that the fluorescence of the experimental group can be observed by fluorescence microscopy; Second, the SEM image show a clear coating on the stent; Finally, the ninhydrin is used to quantify chitosan, and scaffold can cover about 1000 μg chitosan. Tensile test, Young’s modulus was 0.14 MPa in the control group and 0.43 MPa in the experimental group. Ultimate Tensile Strength was 0.10 MPa in the control group and 0.22 MPa in the experimental group. From the above values, the mechanical strength of the experimental group was significantly better than that of the control group (p<0.05). Degradation rate, the experimental group coated with chitosan, and chitosan was insoluble in calcium and magnesium salt buffer solution, therefore the degradation rate was slower, and the degradation rate of the control group on 14 days was about 22.47% compared with 12.98% in the experimental group has significant difference (p<0.05). Drug release rate, on the first day, the difference between the experimental group and the control group was different, Ampicillin difference was about 9%; Tetracycline HCl was about 14%; Chloramphenicol was about 5%, because the experimental group was coated with chitosan, the drug release was delayed. In addition, Chloramphenicol was released in the experimental group for about 13 days, while the control group was released in about 10 days. From the above results, it was concluded that the hydrophobicity of Chloramphenicol can significantly slow down drug release. Drug loading, Chloramphenicol was significantly different from other antibiotics (p<0.05). Because Chloramphenicol was more hydrophobic than other antibiotics, it was not easy to lose or absorb drugs during the manufacturing process. The control group and the experimental group had little difference. Ampicillin is about 107 μg; Tetracycline HCl is about 114 μg; Chloramphenicol is about 32 μg. Inhibition zone, the experimental group and the control group had antibacterial effects against Gram-negative bacteria and Gram-positive bacteria, while the experimental group was coated with chitosan, and the drug release rate was slow, so that the inhibition zone was smaller than the control group. (p<0.05). Finally, human fibroblasts(CRL-2522) were inoculated on the scaffolds of the experimental group and the control group for 1, 4, and 7 days, and the cells increased, and the typeⅠcollagen was also secreted normally.
The chitosan-coated scaffold can not only slowly release a sufficient amount of antibiotics, but also does not hinder skin repair, and can be used for skin dressing in the future.
| Identifer | oai:union.ndltd.org:TW/106TIT0506A069 |
| Date | January 2018 |
| Creators | Tie-Kun Peng, 彭鐵坤 |
| Contributors | 林忻怡 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 89 |
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