Papers by Keyword: Scaffold

Abstract: Recently, regenerative medicine attracts very wide attention. Regenerative medicine is a method of medical care for the purpose of recovery of the lost human organic function, resulted by an accident or diseases. It is considered that there are three important factors in the regenerative medicine, cell, scaffold and cell growth factor. In this research, the talyor made stereolithography method was used to fabricate a highly precise biodegradable scaffold which is suited for individual bone defect part. The sterolithograph, one of rapid prototyping methods, is a method of modeling by using optical hardening resin irradiated by ultraviolet laser. We have used the optical hardening resin by mixing biodegradable β-tcp as the bone formation material. At present, confirmation of detailed fabrication conditions of stereolithography are in proceeding. Experiments by using osteoblasts cells are intended.

Abstract: Atmospheric pressure plasma treatment was used to improve hydrophilic properties and scaffold/cell interaction of poly(S/EGDMA)polyHIPE highly porous foam, prepared from poly(styrene/ethylene glycol dimethacrylate) using high internal phase emulsion technique. With our synthesis procedure and surface treatment, this bioactive material, featuring highly porous structure and good mechanical strength, can be applied as a scaffold for tissue engineering applications. The treatment time and external plasma parameters were investigated in regards to the polyHIPE foam surface’s appropriate for fibroblast implantation. The changes in surface properties were characterized by contact angle measurement, showing that the exposure to air-plasma induced polyHIPE foam with hydrophilic surfaces, as observed by a decrease in contact angle degree. Enhancement of the interaction between the polyHIPE foam and the L929 fibroblast-like cells would imply the hydrophilic improvement of the polyHIPE foam surface due to the polar-like property of the biofluid cell medium.

Abstract: The performance of biomaterial scaffolds for bone tissue engineering, as porous titanium implants, is strongly dependent of its structural features. A reliable structural characterization of this kind of implant is very important. The most of image analysis techniques just supplies 2D information about the structure of specimens. X-ray microtomography is imaging technique that can produce 3D images of samples, however, stochastic models can also estimate properties of porous materials in 3D. This work presents the evaluation of a 3D model (using a truncated Gaussian method) in comparison to 3D microtomography volume, both from a titanium scaffold sample. In order to compare, geometrical parameters were measured for both 3D volumes. By the results, the truncated Gaussian 3D method reproduced a model with similar values to the microtomography volume, showing a good agreement among data, which suggests the use of this technique to estimate physical parameters of titanium scaffolds

Abstract: Low-temperature deposition manufacturing (LDM) has been proven as an effective bone scaffold preparation process, but its further application has been seriously hindered by the existing material over-accumulation problem. In view of the over-accumulation problem of the traditional pneumatic extrusion material feeding way, designed and developed a feeding system based on pneumatic-extrusion and valve-control, which can achieve rapid pressure/relief, Combined with the inflation / deflation time calculation method of fixed volume container for analysis and calculation. A unified data management method of the material feeding device and a regulation scheme of the controller are given. Experimental results show that, by adjusting parameters, the feeding system based on pneumatic-extrusion and valve-control can achieve rapid gas pressure/relief, the flux has been well controlled, the over-accumulation on deposition path at the end has been eliminated, which lead to effective guarantee of scaffold forming quality.

Abstract: Tissue engineering of airway tissues poses many complex challenges. As tissue form is determined by function and vice versa, it is necessary to consider mechanical and physiological constraints in conjunction with standard biologic and biochemical factors when culturing tissues in vitro. This study involved the development and validation of a novel 3-dimensional (3-D) construct with the capacity to periodically expose a cell scaffold to air and medium at application of physiologic strain rates. The ultimate objective was to mimic respiratory conditions experienced by airway tissues during breathing whilst ensuring compatibility with proven cell culture techniques. The Biaxx design consists of an elastomeric porous synthetic scaffold integrated with a unique biopolymer coupling unit which engages with an IAXSYS bioreactor actuator. Uniform biaxial strain was imparted by the coupling unit whilst simultaneously creating a periodic air-liquid interface. Biaxx scaffolds with and without a coating of particulate 45S5 bioglass were employed in an assay to assess cell attachment and proliferation whilst subject to periodic strain. Physiologic lung tissue strain of 5-15% was achieved for over 200,000 cycles at 0.2Hz. Preliminary biological studies with H460 human lung carcinoma cells confirmed cell attachment, growth and proliferation on this promising construct.

Abstract: In this paper, a novel simple method for VEGF immobilization was developed using a new genetically engineered vascular endothelial growth factor (VEGF) fused to IgG-Fc (abbreviated as VEGF-Fc). The fusion protein of VEGF-Fc was biosynthesized by eukaryocyte expression system with the cloning plasmid encoding VEGF165 and Fc domain. Owe to the hydrophobic-bind property of the Fc domain, the VEGF-Fc is efficiently immobilized on the surface of porous polycaprolactone (PCL) scaffold in our study. The quantitative assay of VEGF-Fc immobilization by ELISA showes that the VEGF-Fc can uniformly distributed throughout the PCL scaffold and the immobilization rate is above 96% that is much higher than that of commercial VEGF. Furthermore, the proliferation of HUVECs was improved two times in the VEGF-Fc immobilized PCL scaffold comparing with that in commercial VEGF in cell culture medium, which detected by the cellular glucose consumption assays.

Abstract: Zirconia-alumina ceramic foam scaffolds with a nanocrystalline HAP coating were used for the preparation of integrated motile orbital implants. This study demonstrated that open-cell ceramic foams with enhanced strength-to-density ratio are quite suitable as biocompatible materials for the manufacture of orbital implants for post-enucleation syndrome treatment. In-vivo studies demonstrated that the application of a nanocrystallyne (not sintered) HAP coating facilitated the formation of dense fibrous capsule around the implant as well as the fast tissue ingrowth into the implant’s internal space. Orbital implants with the optimized pore size and HAP content were implanted to the animal’s eye cavity with their fixation to the extraocular muscles, and their motility was ensured.

Abstract: Neural stem cells (NSCs), as therapeutic agents, play the key role in the treatment of central nervous system (CNS) disorders. It is a researching tendency for promote proliferation and differentiation of neural stem cells by using tissue engineering. It is discovered that joint use neural stem cells and NSCs-seeded scaffold may increase the cell survival state and better control cellular microenvironment. We find suitable material include natural biological materials, synthetic materials, compound materials, bio-derived materials and 3D-materials of neural stem cells tissue engineering by analyzing and summing up of the research which combine tissue engineering with NSCs transplant in past several years. It hold out a hope of the possibility of utilizing the treatment of neural stem cells transplantation with tissue engineering, and there has been a great quantity of achievements on the research of it to treat CNS disorders by promote proliferation and differentiate.

Abstract: The relationship between the porosity and the mechanical property was still a bottle-neck in bone tissue engineering scaffold. Porosity increasing may reduce the scaffold strength. In order to solve the contradiction, the idea of enhancing the mechanical properties by controlling the scaffold porosity was proposed in this paper. Using reverse engineering technology, 5 different porosity cranium scaffolds were first established. Their FE models were built through FE surface preprocessing and volume fitted meshing. According to results of static analysis, the displacements and stresses of the 5 porosity scaffolds were compared and discussed and it indicated that the 36% porosity bionic scaffold have good porous level and mechanical properties.

Abstract: The silk fibroin/sodium alginate scaffolds were prepared using lyophilization method. And then, the blend scaffolds were treated with calcium ions. The morphology of the blend scaffolds exhibited a thin layer structure before calcium ions treatment, and much more rod-like structure appeared at the layer surface with adding the increase content of sodium alginate in the blend scaffolds. After calcium ions treatment, much more rod-like structure disappeared after adding 30% sodium alginate or more in the blend scaffolds. Wide angle X-ray diffraction and Fourier transform infrared analysis results confirmed the crystal structure of silk fibroin was not influenced by adding the different content of sodium alginate, exhibiting the silk I and silk II structure co-existed in the blend scaffolds. And the same time, the average mass loss value of the blend scaffolds was higher than the pure silk fibroin scaffold, reaching 9.884%, 11.2%, and 8.626%, respectively, when the blend scaffolds contained 10%, 30%, and 50% sodium alginate, respectively. Thus, the silk fibroin/sodium alginate scaffolds should be a useful biomaterial applicable for a wide range of tissue engineering.