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Dear manoj kumar valluru, Last week 4 patents of relevance to the area of stem cells were issued. - # 7,347,876 (Patent Spotlight), describes how to expand limbal stem cells using amniotic membranes as a support matrix.
- # 7,348,015 cancer vaccine by inserting bacterial immune evasion gene into the mammalian cancer cell.
- # 7,347,999 teaches how to reconstitute a hematopoietic system.
- # 7,349,740 an example of how to write strong claims.
| | Patent Number: 7,347,876 Corneal transplants are performed as a result of chemical or inflammatory injury to the clear part of the eye. Efficacy of corneal transplantation is decreased when the limbal stem cells which produce corneal epithelium are damaged or defective. Accordingly, transplantation of limbal stem cells has been performed clinically. A report in 1999 documented positive effects in some of the 70 patients treated. One of the issues with limbal stem cell transplantation is lack of donors or poor quality of the donor graft. The current patent addresses this problem by expanding ex vivo corneal epithelial stem cell. The current patent has 2 independent claims. The first one covers "a surgical graft" that is made of: - an amniotic membrane - an extracellular matrix - epithelial stem cells. The second independent claim covers "a method for creating a surgical graft" through the steps of - placing healthy epithelial stem cells in an isolated amniotic membrane - enabling healthy epithelial stem cells to expand on the membrane A very interesting point is that while the filing date of the patent is 2001, a recent publication (Yeh et al. Cryopreservation of Human Limbal Stem Cells Ex Vivo Expanded on Amniotic Membrane. Cornea 2008 Apr;27(3):327-333) not only demonstrated that limbal stem cells can be expanded in vitro on amniotic membranes but also that they can be cryopreserved for later use. Noteworthy for people interested in this patent, an issued patent exists covering methods of collecting limbal stem cells, as well as the expansion of conjunctival stem cells is also patented. Ask a question OR leave your comments. | | |
| | Mesenchymal Stem Cells in the Eye
Sunday March 30th, 2008 @ 20:24:11 EST Hyderabad, India -
Mesenchymal stem cells are one of the most clinically advanced forms of stem cell therapy after hematopoietic stem cell transplantation. The conventional source for mesenchymal stem cells has been bone marrow, however these cells can also be extracted from a variety of other tissues such as teeth, placenta, cord blood, and menstrual blood. A recent publication (Polisetty et al. Mesenchymal cells from limbal stroma of human eye. Mol Vis. 2008 Mar 4;14:431-42) describes mesenchymal stem cells found in the limbus of the human eye. The investigators collected limbal tissues from patient biopsy samples during eye surgery. Cells with a spindle-like morphology were expanded as adherent cells in a medium containing EGF, insulin, and fetal calf serum.
The "mesenchymal" cells expanded from the limbus possessed a similar phenotype to bone marrow derived mesenchymal stem cells. For example, they expressed CD90, CD105, and CD29 and lacked expression of CD34, and CD45. Additionally, the limbal derived mesenchymal cells were capable of differentiating into bone, fat and cartilage tissue. The identification of various subsets of stem cells in the human limbus is important since clinically limbal stem cell transplants have been performed with some degree of success. For example, a paper from 1999 (Tsubota et al. Treatment of severe ocular-surface disorders with corneal epithelial stem-cell transplantation. N Engl J Med 1999 Jun 3;340(22):1697-703) describes 70 corneal epithelial stem cell transplants, in which a statistically significant improvement in vision was observed. Ask a question OR leave your comments. Read more StemCellPatents.com News | | |
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