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Stem Cell Related Patent Number US6287340
| Title: | Bioengineered anterior cruciate ligament | | Inventors: | Altman, Gregory; Medford, MA, USA
Kaplan, David; Stow, MA, USA
Vunjak-Novakovic, Gordana; Belmont, MA, USA
Martin, Ivan; Oberwil, Switzerland | | Summary: | Described herein are methods of producing an anterior cruciate ligament ex vivo. The invention relates to a process by which pluripotent cells, preferably bone marrow stromal cells, which have been seeded into a three-dimensional matrix are then attached to anchors and cultured while the matrix is subjected to mechanical forces through the movement of the attached anchors, resulting in the production of an anterior cruciate ligament ex vivo. Further disclosed are suitable matrix materials to which the cells can adhere, such as a gel made from collagen type I, and suitable anchor materials to which the matrix can attach, such as Goinopra coral and demineralized bone. Optimal mechanical forces are described, to which the matrix is subjected, and which should mimic mechanical stimuli experienced by an anterior cruciate ligament in vivo. Descriptions of the appropriate combination of tension, compression, torsion, and shear, to the matrix are disclosed, such that resulting ligament has fiber bundles which are helically organized. Also included are other mechanical, as well as electromagnetic and chemical stimuli incorporated into the bioengineering process. | | Abstract: | The present invention provides a method for producing an anterior cruciate ligament ex vivo. The method comprises seeding pluripotent stem cells in a three dimensional matrix, anchoring the seeded matrix by attachment to two anchors, and culturing the cells within the matrix under conditions appropriate for cell growth and regeneration, while subjecting the matrix to one or more mechanical forces via movement of one or both of the attached anchors. Bone marrow stromal cells are preferably used as the pluripotent cells in the method. Suitable matrix materials are materials to which cells can adhere, such as a gel made from collagen type I. Suitable anchor materials are materials to which the matrix can attach, such as Goinopra coral and also demineralized bone. Optimally, the mechanical forces to which the matrix is subjected mimic mechanical stimuli experienced by an anterior cruciate ligament in vivo. This is accomplished by delivering the appropriate combination of tension, compression, torsion, and shear, to the matrix. The bioengineered ligament which is produced by this method is characterized by a cellular orientation and/or matrix crimp pattern in the direction of the applied mechanical forces, and also by the production of collagen type I, collagen type III, and fibronectin proteins along the axis of mechanical load produced by the mechanical forces. Optimally, the ligament produced has fiber bundles which are arranged into a helical organization. The method for producing an anterior cruciate ligament can be adapted to produce a wide range of tissue types ex vivo by adapting the anchor size and attachment sites to reflect the size of the specific type of tissue to be produced, and also adapting the specific combination of forces applied, to mimic the mechanical stimuli experienced in vivo by the specific type of tissue to be produced. The methods of the present invention can be further modified to incorporate other stimuli experienced in vivo by the particular developing tissue, some examples of the stimuli being chemical stimuli, and electro-magnetic stimuli. Some examples of tissue which can be produced include other ligaments in the body (hand, wrist, elbow, knee), tendon, cartilage, bone, muscle, and blood vessels. | | US Patent Website: | Click Here for Full Text of Patent | | Title Number: | US6287340 | | Application Number: | US1999000312203 | | Date Filed: | 14/05/1999 | | Date Published: | 11/09/2001 | | Assignee: | Trustees of Tufts College, Boston, MA, USA |
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