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US 4,871,671 AGranted
Immobilization of biological cells in polytetrafluoroethylene matrix
AssigneeMinnesota Mining and Manufacturing Company
InventorsLouis A. Errede, George R. Hunt
Life of this patent
Estimating the term…
Abstract
Articles which are composite structure are prepared which comprise a fibrillated polytetrafluoroethylene (PTFE) matrix containing enmeshed and immobilized therein viable cells capable of their usual and continuous biochemical and biological performances. The viable cells cells can be animal, bacterial, fungal or yeast. Almost all cells entrapped within said matrix are separated from each other and are unbound within said matrix such that when said matrix is cut the cells of the cut edge are free to escape from the matrix.
Claims41
A composite structure comprising:
- (a) a surfactant and soap-free polytetrafluoroethylene fibril matrix containing micropores uniformly throughout said matrix, and
- (b) 0.005 to 15 parts of viable cells per part of polytetrafluoroethylene by weight entrapped within the micropores of said matrix, such that almost all of said viable cells are separated from each other and are unbound within said matrix such that when said matrix is cut the cells at the cut edge are free to escape from said fibril matrix, said entraped viable cells being capable of their usual and continuous biochemical and biological performances.
A composite structure comprising:
- (a) a surfactant and soap-free polytetrafluordethylene fibril matrix containing micropores uniformly throughout said matrix, and
- (b) 0.005 to 15 parts of viable mammalian cells per part of polytetrafluoroethylene by weight entrapped within the micropores of said fibril matrix and are unbound within said matrix such that when said matrix is cut the cells at the cut edge are free to escape from said fibril matrix, said entrapped viable cells being capable of their usual and continuous biochemical and biological performances.
A composite structure consisting essentially of:
- (a) a surfactant and soap-free polytetrafluoroethylene fibril matrix containing micropores uniformly distributed throughout said matrix, and
- (b) 0.005 to 15 parts of viable cells per part of polytetrafluoroethylene by weight entrapped within the micropores of said matrix, such that almost all of said viable cells are separated from each other and are unbound within said matrix such that when said matrix is cut the cells at the cut edge are free to escape from said fibril matrix, said entrapped viable cells being capable of their usual and continuous biochemical and biological performances.
A composite structure consisting essentially of:
- (a) a surfactant and soap-free polytetrafluoroethylene fibril matrix containing micropores uniformly distributed throughout said matrix,
- (b) 0.005 to 15 parts of viable cells part of polytetrafluoroethylene by weight entrapped within said micropores of said matrix, such that almost all of said viable cells are separated from each other and are unbound within said matrix such that when said matrix is cut the cells at the cut edge are free to escape from said fibril matrix, said entrapped viable cells being capable of their usual and continuous biochemical biological performances, and
- (c) greater than 0 and up to 14.995 parts by weight of inert diluent particles per part of polytetrafluoroethylene entrapped within the micropores of said matrix, provided that said vialbe cells plus diluent do not exceed 15 parts cells and diluent to 1 part polytetrafluoroethylene.
A composite structure comprising:
- (a) a surfactant and soap-free polytetrafluoroethylene fibril matrix containing micropores uniformly distributed throughout said matrix, and
- (b) 0.005 to 15 parts of viable cells per part of polytetrafluoroethylene by weight entrapped within the micropores of said matrix, such that almost all of said viable cells are separated from each other and are capable of their usual and continuous biochemical and biological performances,
- said composite structure being prepared by a method comprising the steps of:
- (a) providing a blend consisting essentially of viable cells and surfactant and soap free polytetrafluoroethylene as an aqueous dispersion in the form of a damp paste;
- (b) adding sufficient water as a lubricant to exceed the absorptive capacity of the viable cells yet maintain a stiff dough consistency;
- (c) intensively mixing said stiff dough at a temperature in the range of 5.degree. to 70.degree. C. to fibrillate said polytetrafluoroethylene, and
- (d) biaxially calendering the resultant mass between calendering rolls at a temperature in the range of 5.degree. to 70.degree. C. and a pressure in the range of 1000 to 3000 MPa to cause further fibrillation of said polytetrafluoroethylene to provide said composite structure, said heating being controlled to preserve the viability of the cells.
4 more elements
A composite structure consisting essentially of
- (a) a surfactant and soap-free polytetrafluoroethylene fibril matrix containing micropores uniformly throughout said matrix, and
- (b) 0.005 to 15 parts of viable cells per part of polytetrafluoroethylene by weight entrapped within the micropores of said matrix, such that almost all of said viable cells are separated from each other and are capable of their usual and continuous biochemical and biological performances, and
- (c) greater than 0 up to 14.995 parts per part polytetrafluoroethylene of inert diluent particles admixed with said viable cells,
- provided that said viable cells plus diluent do not exceed 15 parts cells and diluent to 1 part polytetrafluoroethylene,
- said composite structure being prepared by a method comprising the steps of:
- (a) providing a blend consisting essentially of viable cells, diluent particles and surfactant and soap free polytetrafluoroethylene as an aqueous dispersion in the form of a damp paste;
- (b) adding sufficient water as a lubricant to exceed the absorptive capacity of the viable cells yet maintain a stiff dough consistency;
- (c) intensively mixing said stiff dough at a temperature in the range of 5.degree. to 70.degree. C. to fibrillate said polytetrafluoroethylene, and
- (d) biaxially calendering the resultant mass between calendering rolls at a temperature in the range of 5.degree. to 70.degree. C. and a pressure in the range of 1000 to 3000 MPa to cause further fibrillation of said polytetrafluoroethylene to provide said composite structure, said heating being controlled to preserve the viability of the cell.
6 more elements
Dependencies are inferred from the claim text.