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The Preparation and the Study of Biological Performance of Nano Hydroxyapatite/Chitosan/Tussah Silk Protein Ternary Mixed Materials

Author: ZhangJiBo
Tutor: ZhengDeYu
School: Liaoning Medical
Course: Human Anatomy and Embryology
Keywords: Tussah silk fibroin hydroxyapatite composite scaffolds biocompatibility
CLC: R318.08
Type: Master's thesis
Year: 2013
Downloads: 8
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Abstract

ObjectiveWe prepare the n-HA/CS/TSF composition artificial bone scaffold byfreeze-drying methods. To discuss the biological characters andbiocompatibilities of the artificial scaffold and provide the foundation for the nextexperiment and clinical using.MethodsWe purify the tussah silk fibroin and make the amino acid analysis.Simulation composition of natural bone, we take the freeze-drying preparation ofthe n-HA/CS/TSF composite Manual bone scaffold， according to thepercentage of the n-hydroxyapatite/chitosan/tussah silk fibroin, divided into theexperiment control group(n-HA/CS---70/30), the experiment group1(n-HA/CS/TSF1---70/20/10), the experiment group2(n-HA/CS/TSF2---70/15/15), and the experiment group3(n-HA/CS/TSF3---70/10/20). The HA was usedas control group. the morphology and porosity, pore size were detected byscanning electron microscope. The water absorption and mechanical propertieswere tested according to IS010993standards. The degradation and the PHvalue were observed by dipped into PBS methods in vitro. Fifty SD rats weredivided into experimental group and the control group at randomly, every groupwere10; The artificial scaffold n-HA/CS/TSF1~3, n-HA/CS and HA weresubdivided into5x5x5mm3and transplanted into bilateral sides of spinal column.At2nd,4th,8th,12thand24thweeks, the transplanted scaffold were detected ongross observation, histologic observation by HE staining and the degradation rate test in vivo. Bone marrow mesenchymal stem cells (BMSCs), isolated andprimary cultured from Japanese milk rabbit, were transplanted on the artificialscaffold and co-cultured3,5,7days. The cell’s adhesion and proliferation onscaffold surface were detected by the cell count and MTT methods, and thesurface adsorption were detedcted by the scanning electron microscopy at theday of3,and7.ResultsThe morphology features of the n-HA/CS included: the every hole wereregular and in round shape, and uniform distribution. the average pore diameterwas446μm, and porosity was50%. Acoompay with the increase of TSF, theholes are ranked in the parallel patterns and a little bit like the "fence"appearance of the n-HA/CAS/TSF1~3. The small cells were communicated eachother and there was a trend that the diameter were decreased and porositywere increased according the TSF percent increased. And the artificial surfacehad a small particles a little bit prominent and well-distributed. Though the poresize become narrow of the n-HA/CS/TSF1~3according with the increase of thecontent of TSF, the diameter more than221um. And the voidage was increasedand more than62%. For the compressive strength, that were hit the42.65Mpaof the n-HA/CS/TSF1~3and more than that of the n-HA/CS, which only33.12Mpa. The artificial scaffold were basically fitting for the requests for the bonytissue engineering. The water absorption and degradation in vivo and in vitroweresignificant differences between groups with TSF content, which were allobviously better than the HA vector group. These results all had significantstatistical sense（P<0.05）. There were almost not inflammatory response of allgroups by detected by HE dying. Degeneration speed of HA was lowest.According the TSF increased, Degeneration speed of the n-HA/CS/TSF1~3werefaster than that n-HA/CS. The capillaries were found at2ndweeks after artificialscaffold transplanted into the besides of the vertebral column. And there were atrend to biodegeneration of the scaffold from2ndweek. The TSF contents couldregulate the speed of degradation. The n-HA/CS/TSF1~3scaffolds werenon-toxic, and could promote MBSCs adhesion and proliferation. n-HA/CS/TSF2 is better than n-HA/CS/TSF1in the cell adhesion, growth, and proliferation byelectron microscop, which is statistically significant（P<0.05）.ConclusionN-HA/CS/TSF1, n-HA/CS/TSF2mixed ternary scaffold material hadgood pore size, voidage, water absorption and biomechanical characteristics,non-toxic, moderate degradation. they had very good adhesion and proliferationfor the rabbit BMSCs.

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CLC: > Medicine, health > Basic Medical > Medical science in general > Biomedical Engineering > General issues > Biomaterial
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