Development And Experimental Research Of A Biological Three-dimensional Printing Compound Molding System Oriented To Tissue Engineering

Tissue damage repair is a hotspot in tissue engineering research.Using tissue scaffolds to complete tissue repair and reconstruction is one of the most common treatment methods used in clinic.Compared with the traditional scaffold manufacturing methods,the bio-printing technology has the advantages of being able to manufacture a complicated structure with personality and high precision.With the development and progress of bio-printing technology,precise manufacturing of target tissue substitutes is of great significance in the field of tissue engineering research.In order to realize the structure-function integrated manufacturing of the target tissue,this paper designed a bio-printing device based on composite manufacturing technologies.Then printing experiments and tests were conducted by taking meniscus scaffold as an example to verify the possibility of the designed device.The main research of this paper is as follows:Firstly,a male volunteer's meniscus CT scanned images were selected as the main data source.In the Matlab GUI environment,the meniscus CT images were binarized,filtered,and edge-detected to obtain a sharply defined image.The Mimics 3D modeling software was used to reconstruct the three-dimensional model of the meniscus,and three different internal structures of the meniscus were designed.The mechanical simulation analysis were carried out in Abaqus to provide data sources for later printing experiments.Secondly,in order to realize the manufacturing of the meniscus scaffold,the functional requirements of the device were analyzed.Then a dual-nozzle bio-printing device with a composite technology was designed combining the fused deposition with the pneumatic extrusion technology.A mechanical frame composed of a three-axis motion frame and an ARM-based electrical control system together form a dual nozzle printing device.Switching control method between dual nozzles was then focused on,leading to a foundation for realizing accurate and reliable operation of the platform.Finally,the bio-printing device based on composite manufacturing technologies was used as the experimental platform.Linear printing test under the two processes were completed and then three cylindrical hydrogel scaffolds(print track angles separately set as 30°,45°,90°)were printed by using the pneumatic extrusion nozzle.The best printing parameters were acquired and the PLA/alginate meniscus scaffolds were printed in the end.The above meniscus model reconstruction and bio-printing experimental research based on composite manufacturing process has important theoretical support and reference value for complex tissue repair including bone and cartilage,and serves scientific guiding value.