ObjectiveTo fabricate the bionic scaffolds of rat spinal cord by combining three dimensional (3D) printer and 3D software, so as to lay the foundation of theory and technology for the manufacture of scaffolds by using biomaterials. MethodsThree female Sprague Dawley rats were scanned by 7.0T MRI to obtain the shape and position data of the cross section and gray matter of T8 to T10 spinal cord. Combined with data of position and shape of nerve conduction beam, the relevant data were obtained via Getdata software. Then the 3D graphics were made and converted to stereolithography (STL) format by using SolidWorks software. Photosensitive resin was used as the materials of spinal cord scaffolds. The bionic scaffolds were fabricated by 3D printer. ResultsMRI showed that the section shape of T8 to T10 segments of the spinal cord were approximately oval with a relatively long sagittal diameter of (2.20±0.52) mm and short transverse diameter of (2.05±0.24) mm, and the data of nerve conduction bundle were featured in the STL format. The spinal cord bionic scaffolds of the target segments made by 3D printer were similar to the spinal cord of rat in the morphology and size, and the position of pores simulated normal nerve conduction of rat spinal cord. ConclusionSpinal cord scaffolds produced by 3D printer which have similar shape and size of normal rat spinal cord are more bionic, and the procedure is simple. This technology combined with biomaterials is also promising in spinal cord repairing after spinal cord injury.
ObjectiveTo prepare bionic spinal cord scaffold of collagen-heparin sulfate by three-dimensional (3-D) printing, and provide a cell carrier for tissue engineering in the treatment of spinal cord injury. MethodsCollagen-heparin sulfate hydrogel was prepared firstly, and 3-D printer was used to make bionic spinal cord scaffold. The structure was observed to measure its porosity. The scaffold was immersed in simulated body fluid to observe the quality change. The neural stem cells (NSCs) were isolated from fetal rat brain cortex of 14 days pregnant Sprague-Dawley rats and cultured. The experiment was divided into 2 groups: in group A, the scaffold was co-cultured with rat NSCs for 7 days to observe cell adhesion and morphological changes;in group B, the NSCs were cultured in 24 wells culture plate precoating with poly lysine. MTT assay was used to detect the cell viability, and immunofluorescence staining was used to identify the differentiation of NSCs. ResultsBionic spinal cord scaffold was fabricated by 3-D printer successfully. Scanning electron microscope (SEM) observation revealed the micro porous structure with parallel and longitudinal arrangements and with the porosity of 90.25%±2.15%. in vitro, the value of pH was not changed obviously. After 8 weeks, the scaffold was completely degraded, and it met the requirements of tissue engineering scaffolds. MTT results showed that there was no significant difference in absorbence (A) value between 2 groups at 1, 3, and 7 days after culture (P>0.05). There were a lot of NSCs with reticular nerve fiber under light microscope in 2 groups;the cells adhered to the scaffold, and axons growth and neurosphere formation were observed in group A under SEM at 7 days after culture. The immunofluorescence staining observation showed that NSCs could differentiated into neurons and glial cells in 2 groups;the differentiation rate was 29.60%±2.68% in group A and was 10.90%±2.13% in group B, showing significant difference (t=17.30, P=0.01). ConclusionThe collagen-heparin sulfate scaffold by 3-D-printed has good biocompatibility and biological properties. It can promote the proliferation and differentiation of NSCs, and can used as a neural tissue engineered scaffold with great value of research and application.
ObjectiveTo explore a method of three-dimensional (3D) printing technology for preparation of personalized rat brain tissue cavity scaffolds so as to lay the foundation for the repair of traumatic brain injury (TBI) with tissue engineered customized cavity scaffolds. MethodsFive male Sprague Dawley rats[weighing (300±10) g] were induced to TBI models by electric controlled cortical impactor. Mimics software was used to reconstruct the surface profile of the damaged cavity based on the MRI data, computer aided design to construct the internal structure. Then collagen-chitosan composite was prepared for 3D bioprinter of bionic brain cavity scaffold. ResultsMRI scans showed the changes of brain tissue injury in the injured side, and the position of the cavity was limited to the right side of the rat brain cortex. The 3D model of personalized cavity containing the internal structure was successfully constructed, and cavity scaffolds were prepared by 3D printing technology. The external contour of cavity scaffolds was similar to that of the injured zone in the rat TBI; the inner positive crossing structure arranged in order, and the pore connectivity was good. ConclusionCombined with 3D reconstruction based on MRI data, the appearance of cavity scaffolds by 3D printing technology is similar to that of injured cavity of rat brain tissue, and internal positive cross structure can simulate the topological structure of the extracellular matrix, and printing materials are collagen-chitosan complexes having good biocompatibility, so it will provide a new method for customized cavity scaffolds to repair brain tissue cavity after TBI.