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| Title: | Application of shear flow stress to chondrocytes or chondrocyte stem cells to produce cartilage |
| Inventors: | Seliktar, Dror; Atlanta, GA, USA Dunkelman, Noushin; San Diego, CA, USA Peterson, Alvin Edward; Jamul, CA, USA Schreiber, Ronda Elizabeth; Ramona, CA, USA Willoughby, Jane; Del Mar, CA, USA Naughton, Gail K.; Del Mar, CA, USA |
| Summary: | This invention describes a bio-reactor for use in producing cartilage from cultured mammalian cells. Properties of a growth chamber and a substrate for the attachment of cells are provided, as are methods for applying shear flow stress to the cells. Further disclosed are methods by which chondrocytes, chondrocyte stem cells, or myoblasts and fibroblasts which transdifferentiate into chondrocytes, are cultured under a shear flow stress of approximately 1 to 100 dynes/cm2 to produce artificial cartilage. Claims of the invention include cells subjected to this shear flow stress which display enhanced maintenance of chondrocyte phenotype while also producing an extracellular matrix containing an enhanced ratio of type II collagen to type I collagen. The substrate is described as being a scaffold, or a nonporous surface such as the surface of a rotatable drum or disc, or the surface of a static plate that supports cell growth in a monolayer, from which cartilage is produced when the substrate is covered with a liquid growth medium and inoculated with the medium cells capable of producing cartilage. Conditions are described under which the cells are allowed to attach to the substrate to which relative movement is applied and maintained between the growth medium and the cells to provide the shear flow stress required to produce the shear flow stressed cells, the culturing of which produces the cartilage. Therapeutic applications are included for surgical transplantation in the replacement of damaged or missing cartilage. |
| Abstract: | Mammalian cells capable of producing cartilage are cultured under a shear flow stress of about 1 to about 100 dynes/cm.sup.2 to produce artificial cartilage for surgical transplantation to replace damaged or missing cartilage. Shear flow stressed cells display enhanced maintenance of chondrocyte phenotype and produce an extracellular matrix containing an enhanced ratio of type II collagen to type I collagen. The cells may be chondrocytes, chondrocyte stem cells or cells such as myoblasts or fibroblasts that transdifferentiate into chondrocytes. A bioreactor is used containing a growth chamber having a substrate on which the cells capable of producing cartilage are attached, and means for applying relative movement between a liquid culture medium and the substrate to provide the shear flow stress. The substrate may be a scaffold, or a nonporous surface such as the surface of a rotatable drum or disc, or the surface of a static plate that supports cell growth in a monolayer. Cartilage is produced by covering the substrate with a liquid growth medium, inoculating into the medium cells capable of producing cartilage, allowing the cells to attach to the substrate, applying and maintaining relative movement between the growth medium and the cells to provide the shear flow stress to produce shear flow stressed cells, and culturing the shear flow stressed cells to produce cartilage. |
| US Patent Website: | Click Here for Full Text of Patent |
| Title Number: | US5928945 |
| Application Number: | US1996000753104 |
| Date Filed: | 20/11/1996 |
| Date Published: | 27/07/1999 |
| Assignee: | Advanced Tissue Sciences, Inc., La Jolla, CA, USA |