US5000963A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of treating the skin using human epidermal sheets
Assignee: Individual
•
Filing: 1988-06-08
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Granted: 1991-03-19
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Expires: 2008-06-08
Abstract
Abstract Procedures are disclosed for eliminating immune competent cells from a population of human epidermal cells. The cells free of immune competent cells are used for growing tissue sheets suitable for transplantation to recipients unrelated to the donor.
Inventors
- 👤 John M. Hefton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:31
CPC Classifications
C; C12; C12N; C12N5/00; C12N5/06; C12N5/0602; C12N5/0625; C12N5/0629; A; A61; A61K; A61K35/00; A61K35/12; A61K35/36; A61L; A61L27/00; A61L27/50; A61L27/60; C12N2509/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
72 words
A process of treating a patient needing a skin transplant which comprises applying to afflicted areas an epidermal sheet produced by a process comprising treating a subpopulation of dissociated human epidermal cells with DNas in an amoutn sufficient to segregate immune competent cells from non-immune competent cells, thereafter recovering the non-immune competent cells as single cells, and growing an integral, self-supporting sheet of non-immune competent epidermal cells from said sub-population of cells.
Claim 2
Dependent Claim
72 words
A process of treating a patient needing a skin transplant which comprises applying to afflicted areas an epidermal sheet produced by a process comprising treating a subpopulation of dissociated human epidermal cells with DNas in an amoutn sufficient to segregate immune competent cells from non-immune competent cells, thereafter recovering the non-immune competent cells as single cells, and growing an integral, self-supporting sheet of non-immune competent epidermal cells from said sub-population of cells.
Claim 3
Dependent Claim
19 words
The process of claim 1 wherein the sub-population of cells consists of cells which do not express HLA-Dr antigen.
Claim 4
Dependent Claim
18 words
The process of claim 1 wherein the sheet is grown at a pH of about 6.5 to 7.2.
Claim 5
Dependent Claim
31 words
The process of claim 1 wherein the sheet of epidermal cells attaches to a tissue culture vessel and the sheet is detached for the vessel by treating with a neutral protease.
Claim 6
Dependent Claim
24 words
The process of claim 1 wherein the dissociation of cells is aided by incubation of the skin in a 0.3 to 0.75% trypsin solution.
Claim 7
Dependent Claim
12 words
The process of claim 1 wherein the afflicted areas are burn wounds.
Claim 8
Dependent Claim
40 words
A process of treating a patient needing a skin transplant which comprises applying to afflicted areas a self-supporting epidermal sheet grown in tissue culture and consisting of essentially non-immune competent human epidermal cells being essentially free of immune competent cells.
Claim 9
Dependent Claim
40 words
A process of treating a patient needing a skin transplant which comprises applying to afflicted areas a self-supporting epidermal sheet grown in tissue culture and consisting of essentially non-immune competent human epidermal cells being essentially free of immune competent cells.
Claim 10
Dependent Claim
20 words
The process of claim 7 wherein the tissue culture is carried out at a pH of about 6.5 to 7.2.
Claim 11
Dependent Claim
26 words
The process of claim 8 wherein the tissue culture is seeded in a medium at a density of 10 5 to 10 8 cells per milliliter.
Claim 12
Dependent Claim
12 words
The process of claim 7 wherein the afflicted areas are burn wounds.
References Cited (Backward Citations)
US4299819A
Cited
US4304866A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-03-18 | 1994-09-17 | 1995-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-18 | 1998-09-17 | 1999-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-18 | 2002-09-17 | 2003-03-19 | $7700.00 | Window Closed / Lapsed |