A kind of multifunctional bio print system and prepare the method for organizational project organ based on biological printing systemTechnical field
The present invention relates to biomedical engineering and field of medical technology, particularly a kind of many shower nozzles, many materials biological printing system and prepare the method for organizational project organ based on biological printing system.
Background technology
The human organ defect caused by various accident, wound or disease can cause dysfunction, traditional restorative procedure adopts allosome transplant operation, although this method can obtain satisfactory effect, but donor organ source is very limited, in addition, because immunological rejection needs life-time service immunosuppressant, so a lot of complication and additional injury may be caused.After the 80's scientist proposes " tissue engineering " concept first, tissue engineering technique is for the treatment of numerous tissue defects, patient organ failure brings dawn, three elements in organizational project mainly comprise the microenvironment of seed cell, timbering material and Growth of Cells, and wherein timbering material is for supporting the frame material that cells grown is a complete tissue, therefore becoming one of key of Tissue Engineering Study and clinical practice thereof.Tissue engineering bracket material for Organ printing should have following characteristics: good biological tissue's compatibility, does not cause the immunological rejection of body, avirulence; There is biodegradability and degraded controllability, plasticity and certain mechanical strength; Have certain porosity, good surface activity, maintain growth its on cellular morphology and phenotype; And sticking and breed, inducing tissue regeneration of cell can be promoted.At present, Biomaterials in Tissue Engineering Scaffolds mainly divides two large classes: natural biologic material is (as de-cell epimatrix, polysaccharide, fibroin albumen and collagen etc.) and the degradation material (as polyglycolic acid and complex, polylactic acid, polylactic acid and polyglycolic acid copolymers etc.) of synthetic.The advantage that natural biologic material is given prominence to is: good biocompatibility, similar to extra-cellular matrix structure, be beneficial to sticking, breed and breaking up of cell, toxicity is little, easy degraded, inflammation is not produced, so there is the incomparable advantage of synthetic material as the timbering material of cell culture in organizational project after catabolite is absorbed by the body.In view of the foregoing, the tissue engineering bracket adopting natural biologic material preparation to be applicable to human nerve regeneration has become the focus of people's research, but it is long that the rack forming method reported in most of document (as particle pore method, method of electrostatic spinning, lyophilization etc.) often also exists preparation time, the problem such as organic solvent residual and poor mechanical property, limits its application to a certain extent
In recent years, three-dimensional printing technology is developed rapidly and applies preparing in used in tissue engineering natural biologic material support.Three-dimensional printing technology is developed in 1989 by people such as Massachusetts Institute Technology Emanual Sachs the earliest, it is a rapid shaping technique based on ejection-type, it first computer Aided Design (CAD) technology prepare the STL electronic document model of institute's printing objects, then the principle according to " successively print, be layering " prints the object with distinctive appearance or complex internal structure.Its forming process is not by the restriction of any geometry, print position, printing times and print speed can arbitrarily control, different materials can pass through different nozzle printing, the material printed can be solution, suspension or emulsion, therefore, 3 D-printing can be easy to controls local material composition, microstructure and surface characteristic.In addition this technology have easy to operate, the course of processing is flexible, shaping speed is fast, operating cost is low and the feature that reliability is high, has become now one of the most vital new technique in rapid shaping technique field.Document Porous Ti6Al4V scaffold directly fabricating by rapid prototyping(Jia Ping Li.Biomaterials 2006, 27 1223 – 1235) disclose Ti6Al4V powder dissolution is prepared Ti6Al4V jelly in organic solvent, then this jelly is put into printer " print cartridge ", according to the CAD model in three-dimensional printer, successful print has gone out the easy drying and moulding of fibrous Ti6Al4V(), and prepared the rectangular block shape body with loose structure, finally further sinter molding is carried out to this porous block body, and confirm that the cellular Ti6Al4V blocks of this printing has the function promoting that osteocyte adheres to and grows, in the potential using value of field of tissue engineering technology tool.Document 3D Fiber-Deposited Electrospun IntegratedScaffolds Enhance Cartilage Tissue Formation(Lorenzo Moroni. Adv. Funct.Mater. 2008,18,53 – 60) disclose the vesicular texture that use in conjunction three-dimensional printing technology and melting electrostatic spinning rule have successfully prepared PEOT/PBT polymer, this porous polymer structure has the effect of good Promote cell's growth equally.In addition, document Incorporation of growth factor containing Matrigel promotesvascularization of porous PLGA scaffolds(M. W. Laschke, J Biomed Mater Res85A:397 – 407,2008) reported the PLGA three-dimensional printer of melting has been printed as porous network structure, and growth factor-loaded for revascularization, find that growth factor-loaded porous PLGA network can promote the structure of tissue engineering blood vessel faster
The above-mentioned material used relates generally to inorganic material and synthetic macromolecular material, and this kind of material often has the features such as good mechanical property, resistance to elevated temperatures and easy machine-shaping, so than being easier to for 3 D-printing molding preparation field.Utilize this kind of material of 3 D-printing molding by the reparation attempted for osseous tissue, skin histology, nervous tissue and cardiovascular organization etc., and achieve certain Preliminary Study Results.But, for some natural biologic materials (extracellular matrix protein, polysaccharide molecule and fibroin albumen quasi-molecule etc.), due to the particularity of its character, as having the feature of the not easily machine-shaping such as mobility after non-refractory, changeableness, obtain solution, greatly limit its application in 3 D-printing forming field.Natural biologic material three-dimensional printing technology at present for organizational project mainly comprises the methods such as heat injection printing technique, piezoelectricity printing technique, laser printing, and its printing shaping method mainly comprises the sedimentation method, thermosetting method, injects method of molding and cross-linking method.Wherein, only has a small amount of reported in literature by natural biologic material with the research of synthetic material compound in order to 3 D-printing molding, document " Fabrication of 3D chitosan – hydroxyapatite scaffolds " (T.H.Ang. Materials Science and Engineering C 2002, 20:35 – 42) method that adopts three-dimensional printing technology and the sedimentation method to combine, utilize the feature of insolubility, chitosan and hydroxyapatite mixed liquor are printed in the mixed solution of NaOH and ethanol, form a kind of precipitate of similar water gel, then lyophilizing molding is carried out to this precipitate, obtain the compound rest of chitosan and hydroxyapatite.Although natural biologic material chitosan has been carried out printing shaping, but in the process printed, mainly still by means of the mechanical property being used for improving article shaped of hydroxyapatite, and owing to being directly be printed on molding in solution, therefore the stability controlling article shaped shape is difficult to, support form easily changes, in addition, because natural biologic material has specific biological characteristics (conformation change, easy degeneration etc.), therefore not all this kind of material is all applicable to sedimentation method molding.At present, there is no bibliographical information and three-dimensional printing technology is specifically applied to independent a kind of natural biologic material.
Summary of the invention
The present invention is directed to prior art deficiency, provide a kind of many shower nozzles, many materials the biometric print decorum and prepare the method for organizational project organ based on biological printing system, controlled the temperature of printing environment by sterile constant-temperature device, timbering material can be made to solidify the survival rate that can ensure again cell.
The concrete technical scheme of the present invention is as follows:
A kind of multifunctional bio print system, comprises control system, biometric print machine and sterile constant-temperature device
The method that above-mentioned control system can adopt this area routine to use carries out computer-aided design (CAD) modeling.These designs can derive from the digitized image reconstruct to natural organ or tissue.Such as by obtaining view data to the three-dimensionalreconstruction etc. of the noninvasive scanning of human body (as MRI or CT) or meticulous layering, also can utilize some theoretic principles, design that rule carries out space structure, obtaining the data structure of tissue
Above-mentioned biometric print machine comprises 6 removable printing heads, with the microinjection type electric spray of electric heater unit, piston switch type pneumatic sprayhead and displacement type piezo jets (Fig. 1).Of the present invention with electric heater unit microinjection type electric spray for printing the development of full-bodied timbering material, by electric heater unit, can heat as required and change the viscosity of timbering material, obtain the fluid of required jet performance.Shower nozzle is all steel structure, and jet thrust is large, stable performance, and Quick-detachable cleaning is sterilized.But when microinjection type electric spray prints low-viscosity timbering material, because material movement inertia is comparatively large, stop-spraying later a small amount of material can flow out from nozzle, produces " curtain coating " phenomenon, therefore this is not enough to this, have developed again piston switch type pneumatic sprayhead for printing the timbering material of low-viscosity.Cell printing adopts the displacement type piezo jets of MicroFab company, strong to Cell sap control ability, and easily realize high accuracy and spray, little to cell damage, cell survival rate is greater than 90%.Timbering material for different organizational project organs is different with cell selects suitable printing head
The present invention devises the sterile constant-temperature device of biometric print machine, make it with sterilizing function, can sterilizing be carried out after printed material has installed additional, reach the object of purification printing environment, and printing environment can be made to keep making timbering material solidify the temperature that can make again cellular activities.
Present invention also offers and utilize above-mentioned multifunctional bio printer system to prepare the method for organizational project organ, comprise the following steps:
(1) set up the computer mock-up of the implant that will print, described physical model derives from different tissues and the organ of human body, carries out slicing delamination to it, obtains the shape information of every layer, and by plane information by software rasterizing;
(2) preparation needs the multiple timbering material and the various kinds of cell liquid that carry out organizational project Organ printing;
(3) by all shower nozzle disassembly, cleaning sterilizations;
(4) timbering material step (2) prepared and Cell sap join in the shower nozzle printing this material respectively, after closing printing environment, carry out disinfection by ultraviolet light 30 minutes;
(5) file containing organ shape information step (1) designed is input in the software of control system, controls the work of biometric print machine;
(6) operating ambient temperature of biometric print machine is controlled between 0 to 40 DEG C, printer head moves along xy axle on print platform, translational speed is 1-20mm, form the back-shaped planar structure (Fig. 2-(1)) of support, after having beaten one deck, printing head moves up 0.15-0.2mm along the z-axis direction, print lower one deck, the back-shaped planar structure printed becomes 90 degree with last layer, rasterizing structure (Fig. 2-(2)) is become after two-layer printing completes, Cell sap (Fig. 2-(3)) is sprayed at the clearance position of grid, after completing, printing head moves up 0.15-0.2mm along the z-axis direction, so repeatedly, successively pile up molding (Fig. 2-(4)), until whole organizational project Organ printing completes
Timbering material in above-mentioned steps (2) can be natural biologic material and synthetic macromolecular material, preferred natural biologic material, one or more more preferably in collagen, extracellular matrix protein, polysaccharide and fibroin albumen
Cell sap in above-mentioned steps (2) contains the glucose, aminoacid, inorganic salt, cell growth factor etc. needed for cell and Growth of Cells for Cell sap.
Beneficial effect of the present invention
(1) the present invention adopts many shower nozzles, the mode of many materials prints organizational project organ, various kinds of cell needed for organ is directly printed in biological support, the cell concentration achieving the precise positioning of different cells in biological support and accurately control required for this position.The present invention can the printing shaping of extensive use and various organization engineering organ, and accurately can control form and the relevant parameter of organizational project organ
(2) the present invention can print and have complicated outside and the organizational project organ of external morphology, can meet clinical needs
(3) the present invention can according to the different needs of tissue or organ, adjustment print parameters, the advantage of printing is combined in conjunction with support and various kinds of cell, the support of energy straight forming natural biologic material and synthetic macromolecular material, and directly print the cell required for this position, for organizational project and regenerative medicine in the position needed.
Accompanying drawing explanation
Fig. 1 is the biometric print machine schematic diagram comprising 6 removable printing heads; Fig. 2 is the work process schematic diagram of biological printer printing head: in Fig. 2, (1) has namely beaten the back-shaped planar structure that one deck forms support, in Fig. 2, (2) i.e. two-layer printing becomes rasterizing structure after completing, in Fig. 2, (3) namely spray Cell sap at the clearance position of grid, and in Fig. 2, (4) namely successively pile up molding.