Abstract:
An apparatus to monitor current density in the application of medicament to a treatment site of a mammalian user of a electrokinetic device including: an applicator cartridge including an active electrode, a matrix carrying a medicament or a medicament and an electrically conductive carrier; a device including an electrical power source connectable to the active electrode, a counter electrode, and an electronic circuit configured to control the application of electrical current through the active electrode to establish a conductive path extending from the power source, through the active electrode, matrix, the treatment site, the user and the counter electrode electrically connected to the power source, and an array of contacts monitoring current density flowing through the matrix and to the treatment site, wherein the array of sensors are arranged monitor the current density at various locations of the matrix and a contact area between the matrix and skin above the treatment site.
Abstract:
A method for determining the viral retentivity of an external jacket of an implantable permselective macrocapsule. Viral retentivity describes the ability of an external jacket to retard the transport of virus particles across the jacket.
Abstract:
Methods and compositions are provided for controlling cell distribution within an implantable bioartificial organ by exposing the cells to a treatment that inhibits cell proliferation, promotes cell differentiation, or affects cell attachment to a growth surface within the bioartificial organ. Such treatments include (1) genetically manipulating cells, (2) exposing the cells to a proliferation-inhibiting compound or a differentiation-inducing compound or removing the cells from exposure to a proliferation-stimulating compound or a differentiation-inhibiting compound; exposing the cells to irradiation, and (3) modifying a growth surface of the bioartificial organ with extracellular matrix molecules, molecules affecting cell proliferation or adhesion, or an inert scaffold, or a combination thereof. These treatments may be used in combination. Cells can be transformed with a proliferation-promoting gene such as the oncogene, SV40, linked to a regulatable promoter such as the Mx1 promoter, the promotor is activated in vitro to express the gene to result in cell proliferation, and the promotor is inactivated before or after insertion of the cells in the bioartificial organ to inhibit expression of the gene to reduce or stop cell proliferation in vivo. The promoter can be reactivated in vivo to again express the gene to result in further cell proliferation. The gene may be a proliferation-suppressing gene such as p53 gene or RB gene, or a differentiation-inducing gene such as high mobility group chromosomal protein 14. Inhibiting gene expression in vitro causes cell proliferation, and inducing gene expression reduces or stops cell proliferation in vivo.
Abstract:
A sealed, implantable, encapsulation device (20) for diffusing a biologically active product or function to an individual which includes a substantially non-porous fitting (32) including an inner surface (33) defining an access port (34). A permselective, porous, membrane (21), having an interior surface (22), cooperates with the fitting inner surface (33) to form a storage cavity (23) therebetween. The membrane interior surface (22) is in substantially cell-tight dry sealing engagement with fitting (32) to seal cavity (23). Living cells (24) are disposed in the cavity (23) which are capable of secreting the biologically active product to an individual. The membrane (21) is of a material capable of permitting the passage of substances between the individual and cells required to provide the biological product or function. A plug member (35) is positioned in the access port (34) and seated in cell-tight sealing engagement with the fitting inner surface (33). A method for sealing the implantable encapsulation device (20) is also provided.
Abstract:
Elongated seamless capsules containing biological material are prepared by a method in which a coagulant, which includes a cell suspension or other biological material, and a polymeric casting solution are extruded through a common extrusion port having at least two concentric bores, such that the coagulant is extruded through an inner bore and the polymeric casting solution is extruded through an outer bore. Extrusion of the coagulant is initiated subsequent to initiating delivery of the casting solution to form a capsule having a curved and smooth leading edge shape. Delivery of the coagulant is then shut off, and extrusion of the casting solution is terminated either immediately or after some predetermined time. This procedure can be modified to form in the capsule a coaxial rod that is connected to one end but not the other end of the capsule. This is accomplished by drawing casting solution into the inner bore after initiating extrusion of the casting solution through the outer bore, and then initiating delivery of the coagulant through the inner bore so as to coagulate the casting solution therein and form a rod, and ejecting the rod from the inner bore by pressure of the coagulant. Delivery of the coagulant and casting solution are then terminated as described above.
Abstract:
This invention relates to methods and compositions of controlling cell distribution within a bioartificial organ by exposing the cells to a treatment that inhibits cell proliferation, promotes cell differentiation, or affects cell attachment to a growth surface within the bioartificial organ. Such treatments include (1) genetically manipulating cells, (2) exposing the cells to a proliferation-inhibiting compound or a differentiation-inducing compound or removing the cells from exposure to a proliferation-stimulating compound or a differentiation-inhibiting compound; exposing the cells to irradiation, and (3) modifying a growth surface of the BAO with ECM molecules, molecules affecting cell proliferation or adhesion, or an inert scaffold, or a combination thereof. These treatments may be used in combination.
Abstract:
A sealed, implantable, encapsulation device (20) for diffusing a biologically active product or function to an individual which includes a substantially non-porous fitting (32) including an inner surface (33) defining an access port (34). A permselective, porous, membrane (21), having an interior surface (22), cooperates with the fitting inner surface (33) to form a storage cavity (23) therebetween. The membrane interior surface (22) is in substantially cell-tight dry sealing engagement with fitting (32) to seal cavity (23). Living cells (24) are disposed in the cavity (23) which are capable of secreting the biologically active product to an individual. The membrane (21) is of a material capable of permitting the passage of substances between the individual and cells required to provide the biological product or function. A plug member (35) is positioned in the access port (34) and seated in cell-tight sealing engagement with the fitting inner surface (33). A method for sealing the implantable encapsulation device (20) is also provided.
Abstract:
Elongated seamless capsules containing biological material are prepared by a method in which a coagulant, which includes a cell suspension or other biologically active factor, and a polymeric casting solution are extruded through a common extrusion port having at least two concentric bores, such that the coagulant is extruded through the inner bore and the polymeric casting solution is extruded through the outer bore. The method involves initiating extrusion of the coagulant subsequent to initiating delivery of the casting solution through the respective bores to form a capsule having a curved and smooth leading edge shape. Delivery of the coagulant is then shut off, and extrusion of the casting solution is terminated either immediately or after some predetermined time.
Abstract:
A device which serves as an artificial pancreas comprises a hollow fiber having an inner diameter of about 5 mm which is surrounded by islets of Langerhans enclosed in a housing. The islets are suspended in a semi-solid matrix which ensures desired distribution of the cells about the hollow fiber. The hollow fiber and suspended islets are enclosed in a housing which further aids the desired distribution of islets about the hollow fiber. The hollow fiber has a porosity which selectively allows passage of substances having a molecular weight of less than about 100,000 Daltons. The semi-solid matrix in which the islets are embedded and suspended is formed of an appropriate supporting material such as alginate or agar.
Abstract:
A sealed, implantable, encapsulation device (20) for diffusing a biologically active product or function to an individual which includes a substantially non-porous fitting (32) including an inner surface (33) defining an access port (34). A permselective, porous, membrane (21), having an interior surface (22), cooperates with the fitting inner surface (33) to form a storage cavity (23) therebetween. The membrane interior surface (22) is in substantially cell-tight dry sealing engagement with fitting (32) to seal cavity (23). Living cells (24) are disposed in the cavity (23) which are capable of secreting the biologically active product to an individual. The membrane (21) is of a material capable of permitting the passage of substances between the individual and cells required to provide the biological product or function. A plug member (35) is positioned in the access port (34) and seated in cell-tight sealing engagement with the fitting inner surface (33). A method for sealing the implantable encapsulation device (20) is also provided.