Dissertation > Excellent graduate degree dissertation topics show

Preparation of magnetic nano- fiber composite materials and the effect of the process of osteogenesis

Author: QiXiaoJin
Tutor: XuHaiYan
School: Peking Union Medical College , China
Course: Biomedical Engineering
Keywords: Bone Tissue Engineering Magnetic nanoparticles Nanofiber structure Regeneration and repair
CLC: R318.08
Type: Master's thesis
Year: 2010
Downloads: 153
Quote: 0
Read: Download Dissertation

Abstract

Human bone defects due to various reasons due to trauma, infection, tumors, congenital malformations and functional loss often require implantation of alternatives to be repaired. Although autogenous bone graft is the treat bone defects recognized \Therefore, the research and development of the ideal artificial bone substitute materials has been one of Biomaterials and tissue engineering concern in the field of important research direction. Bone tissue engineering research focus is to seek the cell seeding bracket and guide new bone ingrowth biological material, which is one of the key issues of tissue engineering research, nano-structured materials in recent years has been confirmed in tissue engineering scaffolds of great The application potential. Natural extracellular matrix distribution in the extracellular space, nano-fiber network is composed of protein and polysaccharide secreted by cells, cell migration, an important role in the regulation of life processes such as proliferation and differentiation. Therefore, the bracket with the structural characteristics of the nanofiber can maximize bionic the characteristics of the natural extracellular matrix by the Investigator more and more attention. Has so far can be prepared by a variety of techniques nanofibers of different materials to simulate the natural extracellular matrix. Electrospinning technology is the long fibers can be prepared by the continuous nano technology, The prepared nonwoven film material having a porosity of nanofiber structures and micron scale, similar with the microscopic structure of the natural extracellular matrix. Can be prepared by the electrostatic spinning technique into nanofibers stent materials including natural materials, synthetic polymeric materials, and composite materials. Polylactic acid (PLA) is a biocompatible and biodegradable characteristics of the polymer, cell growth scaffold material in bone and cartilage tissue regeneration and repair of bone tissue engineering. Hydroxyapatite (HA) is one of the main component of natural bone tissue, has good bone conduction characteristics. Diameter of less than 20nm iron oxide nano-particles having a superparamagnetic (Magnetic nanoparticle, M-NP), enabling the cells in a plurality of tiny magnetic field. The subject electrospinning technology prepared by the PLA, HA and γ-Fe2O3-NP magnetic nanofiber nonwoven composite membrane materials, or applied magnetic field, the composite membrane materials paramagnetic nanofiber structure of mouse osteoblast MC3T3-E1 into bone process. The main contents include: the electrospinning optimized screening process parameters, preparation of magnetic the nanofiber nonwoven composite membrane; observe the microstructure of the composite film morphology by scanning electron microscopy; through the the MTS kit detection of MC3T3-E1 cells in the composite film on proliferation; the BALP kit detects role; secreted alkaline phosphatase function of the composite film on MC3T3-E1 cells were observed through a scanning electron microscope on the magnetic nano fiber scaffolds mineralization; intertransverse bone injury in rabbits The model of the magnetic nanofiber composite membrane for bone tissue repair process and the possible mechanism of action. At the same time, the joint application of the external magnetic field and the magnetic nanofiber materials research role vitro / within bone tissue regeneration and repair. The experimental results show that the application of the electrostatic spinning technique are prepared magnetic nano fiber composite membrane material having a nanofiber network structure similar to the extracellular matrix, a fiber diameter of 300-600nm, a pore diameter of about several microns. The magnetic nano-fiber composite membranes can significantly promote the proliferation of MC3T3-E1, and this effect is more evident in the case of the presence of an applied magnetic field; ALP secretion test results show that in the case of the presence of an applied magnetic field, magnetic nano-fiber composite membrane can significantly promote cell differentiation, earlier and / or more secretion of ALP; scanning electron microscopy observation, plus the presence of a magnetic field, the magnetic nano-fiber composite membranes can significantly promote the process of mineralization of MC3T3-E1. Animal experiments showed that magnetic nano-fiber composite membranes can significantly promote the formation of new bone, joint application of an external magnetic field, the effect is more pronounced. The results of the study for further research and development to be able to guide and promote cell regeneration and repair of bone tissue scaffold has laid a good foundation. This paper also studied the role of the gradient micro and nano structural rearrangement of fibroblast adhesion and skeleton. Closely related to the selection and tissue regeneration and repair fibroblasts as the object of study, using the casting method to prepare a polyurethane (PU) film of the base material, as a cell growth surface has a gradient of micro and nano trench structure; combined microscopic observation, MTS Activity cell detection methods, and means of immunofluorescence analysis, gradient nano-micron trench structure of cell adhesion, proliferation, and the biological behavior of skeleton development, cell spreading. Experimental results show that the micro and nano trench structure able to promote the adhesion and proliferation of fibroblasts on the material surface, and induction of cell response to the growth of micro-nano-trench structure, along with the groove in a direction parallel to skeletal rearrangement. The results for the cell stent design and structure of the surface of the implant design with a reference value.

Related Dissertations

CLC: > Medicine, health > Basic Medical > Medical science in general > Biomedical Engineering > General issues > Biomaterial
© 2012 www.DissertationTopic.Net Mobile