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Fabrication, Characterization and Biocompatibility of Liquid-Electrospinning Novel Three-Dimensional Scaffolds

Author: Li
Tutor: MoXiuMei
School: Donghua University
Course: Biochemistry and Molecular Biology
Keywords: The dynamic liquid - electrostatic spinning Scaffolds Nano yarn Fiber reinforced Tissue Engineering
CLC: R318.08
Type: Master's thesis
Year: 2012
Downloads: 15
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Abstract

The bone is an important human supporting structure having the function of the the protection organ and perform hematopoietic. Massive bone defect is a major problem faced by orthopedic. Tissue engineering for the repair of bone defects new way. Bracket, seed cells, growth factors, the three elements of the tissue engineering. Bone tissue engineering scaffolds basic purpose is to imitate and close to the mechanical properties and structure of cancellous bone. Bone extracellular matrix (extracellular matrix, ECM) is composed of the rigid inorganic substances by the mineralization of organic components and mineralization. ECM plays a vital role in the growth process of the cells, the building has the a similar ECM structure and function of the stent is one of the key technologies of tissue engineering. This paper the dynamic liquid - electrostatic spinning technology to prepare two types of novel biodegradable nanofiber scaffolds, respectively alternating phosphate - calcium liquid impregnation and simulated body fluid (SBF) immersion method biomimetic simulate natural bone tissue structure and ingredients. MC3T3-E1 cell research, two types of stent biocompatibility, and provide a new method for bone tissue scaffold construction. The main contents are as follows: (1) for the first time using a modified the dynamic liquid - electrostatic spinning technology prepared silk fibroin (silk fibroin, SF) and P (LLA-CL) blended nano yarn and pure P (LLA-CL) nano yarn scaffolds with phosphoric acid - calcium liquid alternately dipping method biomimetic mineralization. By scanning electron microscopy and infrared spectroscopy, X-ray diffraction spectroscopy mineralization yarn structure and physicochemical properties of the two kinds of nano. The research results show that the nano yarn is formed by a plurality of nanofibers into shares. Nano yarn ratio SF and P (LLA-CL), P (LLA-CL) on the constituent unit blended nano yarn larger diameter, while the macro-structure rules. SF and P (LLA-CL) Blend, by the reception of the water, can be made SF is rapidly converted to a water-insoluble B-folded Silk II crystalline structure. Infrared spectroscopy, X-ray diffraction spectroscopy confirmed by phosphate - calcium liquid alternately dipping method to make the bracket on the deposition of hydroxyapatite particles. The cell compatibility experiments show, the nanofibers formed nano-yarns greatly affect cell adhesion and migration behavior. The pure polymeric material P (LLA-CL) due to the hydrophobic surface of the lack of cell adhesion functional group, is not conducive to cell proliferation, mixed SF nano yarn stent can effectively promote cell proliferation. MC3T3-E1 cells in the mineralization front and rear two stents are capable of proliferating, wherein P (LLA-CL) / SF, P (LLA-CL)-HA and P (LLA-CL) / SF-HA bracket on the number of cells appear significant proliferation (P gt; 0.05). HE staining proved in the mineralization around nano Yarn shelves have been found in the ingrowth of cells, cell growth along the fibers, showing towards migrating along the fibers throughout the entire stent. Experimental results show that the improved dynamic liquid - Electrostatic spinning technology can provide a three-dimensional scaffold for tissue engineering method, the preparation of three-dimensional yarn is able to overcome conventional electrostatic spinning preparation of a nanofiber membrane causes cell is difficult to grow into the stent. internal disadvantage, is expected to be applied to the bone tissue repair. (2) In order to enhance the mechanical properties of the three-dimensional structure of the nanofibers, the use of fiber reinforced principles combined with freeze-drying technology to prepare a new type of P (LLA-CL), and P (LLA-CL) / SF nano yarn reinforced silk fibroin composite scaffolds, induced by 75% ethanol vapor stent water insolubility. 10 × SBF immersion method biomimetic stent. The results show that the fiber reinforced composite scaffolds porosity, mechanical properties had a huge impact. With nano yarn added, compared to the pure SF stent, the porosity of the two types of fiber reinforced composite scaffold has decreased to some extent, while the mechanical properties are increased significantly. The pure SF a modulus of elasticity of the stent to 1.2848 ± 0.1107MPa, and porosity of about 86.28%. 1.17017 ± O.1619MPa, PLCL-R-SF a modulus of elasticity of the stent increases the porosity is decreased to 84.97%, and the PLCL / SF-R-SF bracket the elastic modulus of the elastic modulus increased to 1.7265 ± 0.5042MPa pore The rate decreased to 82.82%. Mineralization deposition of crystalline particles of calcium and phosphorus ratio (Ca / P) was 1.56, close to the hydroxyapatite Ca / P = 1.67. Infrared spectroscopy, X-ray diffraction spectroscopy further confirmed by 10 × SBF dipping method so that the stent is deposited on the ball type hydroxy apatite particles. PLCL-R-SF-HA and PLCL / SF-the R-the SF-HA bracket on the number of cells has been a significant increase in the resistance (P gt; 0.05), MC3T3-E1 on the stent has been secreted itself significantly extracellular matrix. Spherical hydroxyapatite particles at the nano level may reduce the proliferation of MC3T3-E1 cells early in the bracket, but in the late hydroxyapatite on cell proliferation play a significant role in promoting. The experimental results prove that the fiber-reinforced this approach can greatly improve the mechanical strength of the three-dimensional fibrous scaffold, fiber-reinforced composite scaffold has good potential in the bone tissue repair.

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