Method for designing 3-dimensional porous tissue engineering scaffold

• US 20060129328A1
• Filed: 09/30/2005
• Published: 06/15/2006
• Est. Priority Date: 12/10/2004
• Status: Active Grant

• Current Assignee: Nanyang Polytechnic
• Original Assignee: Nanyang Polytechnic
• Inventors: Leo, Chin Sim, Cheah, Chi Mun
• Granted Patent: US 8,090,540 B2
• Time in Patent Office: Days
• US Class Current: 702/19
• CPC Class Codes: A61F 2/2803 for mandibular reconstruction temporo-mandibular joints A61F2/3099; bone plates for the jaw A61B17/8071
• CPC Class Codes: A61F 2/30942 for designing or making customized prostheses, e.g. using templates, CT or NMR scans, finite-element analysis or CAD-CAM techniques
• CPC Class Codes: A61F 2002/30011 differing in porosity
• CPC Class Codes: A61F 2002/30199 Three-dimensional shapes
• CPC Class Codes: A61F 2002/30838 Microstructures
• CPC Class Codes: A61F 2002/3092 having an open-celled or open-pored structure
• CPC Class Codes: A61F 2002/30948 using computerized tomography, i.e. CT scans
• CPC Class Codes: A61F 2002/30952 using CAD-CAM techniques or NC-techniques
• CPC Class Codes: A61F 2230/0063 Three-dimensional shapes
• CPC Class Codes: A61F 2250/0023 differing in porosity
• CPC Class Codes: B22F 10/20 Direct sintering or melting
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

The present invention provides a method for designing three-dimensional scaffold structures that are anatomically accurate and possess the necessary internal porous micro-architecture design, wherein the porous micro-architecture is necessary for the proliferation and colonization of cultured cells that lead to tissue formation. The design method of the present invention utilizes the patient data derived from medical imaging modalities (e.g., CT or MRI) in combination with computer data manipulation techniques. The present invention further provides that the resultant scaffold design can be easily manufactured by Rapid Prototyping fabrication techniques.

Claims

1. A method for designing a three-dimensional porous scaffold with internal pores and internal channels connecting the internal pores, said method comprising:

generating bitmap templates according to the desired shapes and dimensions of the pores and channels within the scaffold;

the bitmap templates having grids and spacings between the grids;

pre-processing two-dimensional images to obtain the required structure in each image;

duplicating the processed images, wherein the duplicated images are used to fill the slice thicknesses between two consecutive images;

performing Boolean operation between the bitmap templates and the images including the pre-processed and duplicated, thereby the grid pattern of the bitmap templates will be transferred onto the images and will appear as two-dimensional array of pores and channels; and

converting the series of two-dimensional images into STL format;

thereby the three-dimensional porous scaffold is designed.

2. The method of claim 1, wherein, in the step of generating the bitmap templates, the number of different bitmap templates depends on the complexity of the pores and channels.

3. The method of claim 1, wherein, in the step of generating the bitmap templates, the width of the grids and spacings are determined by the shape and dimension of the pores and channels.

4. The method of claim 1, wherein, in the step of pre-processing the two-dimensional images, the pre-processing uses a thresholding process for filtering unwanted data.

5. The method of claim 1, wherein, in the step of duplicating the pre-processed images, the number of duplicates for each slice depends upon the resolution of the DICOM image, the required pore size, or the thickness of the slices.

6. The method of claim 1, wherein, in the step of performing Boolean operation between the bitmap templates and the images, the intersection between the bitmap templates and the images is determined by the pixel intensity of the bitmap.

7. The method of claim 1, wherein the two-dimensional images may be medical image slices taken by CT, MRI, Ultrasound or other computer-based medical imaging systems.

8. The method of claim 1, optionally further comprising:

performing a morphological modification to check, identify and remove all incomplete pores within the image.

9. A method for fabricating a three-dimensional porous scaffold with internal pores and internal channels connecting the internal pores, comprising:

generating bitmap templates according to the desired shapes and dimensions of the pores and channels within the scaffold;

the bitmap templates having grids and spacings between the grids;

pre-processing two-dimensional images to obtain the required structure in each image;

duplicating the processed images, wherein the duplicated images are used to fill the slice thicknesses between two consecutive images;

performing Boolean operation between the bitmap templates and the images including the pre-processed and duplicated, thereby the grid pattern of the bitmap templates will be transferred onto the images and will appear as two-dimensional array of pores and channels;

converting the series of two-dimensional images into STL format;

thereby the three-dimensional porous scaffold is designed; and

fabricating the three-dimensional porous scaffold according to the STL format of the scaffold design.

10. The fabricating method of claim 9, wherein, in the step of generating the bitmap templates, the number of different bitmap templates depends on the complexity of the pores and channels.

11. The fabricating method of claim 9, wherein, in the step of generating the bitmap templates, the width of the grids and spacings are determined by the shape and dimension of the pores and channels.

12. The fabricating method of claim 9, wherein, in the step of pre-processing the two-dimensional images, the pre-processing uses a thresholding process for filtering unwanted data.

13. The fabricating method of claim 9, wherein, in the step of duplicating the pre-processed images, the number of duplicates for each slice depends upon the resolution of the DICOM image, the required pore size, or the thickness of the slices.

14. The fabricating method of claim 9, wherein, in the step of performing Boolean operation between the bitmap templates and the images, the intersection between the bitmap templates and the images is determined by the pixel intensity of the bitmap.

15. The fabricating method of claim 9, wherein the two-dimensional images may be medical image slices taken by CT, MRI, Ultrasound or other computer-based medical imaging systems.

16. The fabricating method of claim 9, optionally further comprising:

performing a morphological modification to check, identify and remove all incomplete pores within the image.

17. The fabricating method of claim 9, wherein, during the step of fabricating the scaffold, the technique includes free-form prototyping.