Abstract: A vascularized bio-artificial pancreas for managing diabetes may include a capsule having a semi-permeable interwoven capsular membrane with tapered conduits, wherein the tapered conduits are smaller in diameter proximate to an outer surface of the semi-permeable capsular membrane and larger in diameter proximate to an inner surface of the semi-permeable capsular membrane; a capsular bead encasing a plurality of the capsules; and a capsular pouch encasing the capsular bead and designed to anchor the capsular bead to a transplantation recipient.

Abstract: An immunoisolation patch system, and particularly a patch system comprising multiple immunoisolation microcapsules, each encapsulating biological material such as cells for transplantation, which can be used in the prophylactic and therapeutic treatment of disease in large animals and humans without the need for immunosuppression.

Abstract: An immunoisolation patch system, and particularly a patch system comprising multiple immunoisolation microcapsules, each encapsulating biological material such as cells for transplantation, which can be used in the prophylactic and therapeutic treatment of disease in large animals and humans without the need for immunosuppression.

Abstract: This invention relates to an immunoisolation encapsulation system that protects cellular transplants and thus allows cell function and survival without the need of immunosuppression. The immunoisolation system is a multi-component, multi-membrane capsule that allows optimization of multiple design parameters independently for reproducible functions in large animal models.

Abstract: This invention relates to an immunoisolation encapsulation system that protects cellular transplants and thus allows cell function and survival without the need of immunosuppression. The immunoisolation system is a multi-component, multi-membrane capsule that allows optimization of multiple design parameters independently for reproducible functions in large animals models.

Abstract: The present invention provides a novel reactor for making capsules with uniform membrane. The reactor includes a source for providing a continuous flow of a first liquid through the reactor; a source for delivering a steady stream of drops of a second liquid to the entrance of the reactor; a main tube portion having at least one loop, and an exit opening, where the exit opening is at a height substantially equal to the entrance. In addition, a method for using the novel reactor is provided. This method involves providing a continuous stream of a first liquid; introducing uniformly-sized drops of the second liquid into the stream of the first liquid; allowing the drops to react in the stream for a pre-determined period of time; and collecting the capsules.

Abstract: The present invention is drawn to a composition of matter comprising high viscosity sodium alginate, cellulose sulfate and a multi-component polycation. Additionally, the present invention provides methods for making capsules, measuring capsule permeability to immunologically-relevant proteins and treating disease in an animal using encapsulated cells.Over one thousand combinations of polyanions and polycations were examined as polymer candidates suitable for encapsulation of living cells and thirty-three pairs were effective. The combination of sodium alginate, cellulose sulfate, poly(methylene-co-guanidine) hydrochloride, calcium chloride, and sodium chloride produced the most desirable results. Pancreatic islets encapsulated in this multicomponent capsule demonstrated glucose-stimulated insulin secretion in vitro and reversed diabetes without stimulating immune reaction in mice.

Abstract: Microspheres of a substantially uniform diameter are produced having a central portion composed of a solution of a polyanion containing a biological material, and an outer permeable membrane enclosing the central portion which is a complex of the polyanion and a polycation. The biological material has a molecular size greater than 150,000 Daltons, and the membrane has a porosity such that the biological material does not permeate the membrane. The biological material may comprise living cells or living tissue. The microspheres are formed by individually enveloping falling droplets of a polyanion solution with a collapsing annular sheet of a polycation solution while the sheet is traveling downwardly at the same velocity as the droplets.

Abstract: A method and apparatus for the accurate non-contact detection and measurement of static electric charge on an object using a reciprocating sensing probe that moves relative to the object. A monitor measures the signal generated as a result of this cyclical movement so as to detect the electrostatic charge on the object.

Abstract: The present invention relates to a method and apparatus for producing uniform polymeric spheres with controllable permeability. This invention may be useful for encapsulating living cells or tissue or chemicals or medicines in uniform polymeric spheres. In particular, this invention relates to polymeric microspheres made from polycation and polyanion polymer solutions. An apparatus includes airtight housing 1 having top 3 and bottom 25 chambers. Top chamber 3 includes pressure regulator means 5, stationary polyanion reservoir tank 7, polycation reservoir tank 27, and feed line 9 to adjustable tank 11. Tank 11 is associated with oscillator 13, nozzle 14 and capacitance means 19. Nozzle 14 and oscillator 3 cooperate to form polyanion droplets. In the bottom chamber 25 annular nozzle 50 is used to form an annular jet of polycation solution. The droplets and polycation jet are mixed at minimal impact velocities to form uniform polymeric sphere.

Abstract: A method is described for forming hollow particles, or shells, of extremely small size. The shell material is heated to a molten temperature in the presence of a gas that is at least moderately soluble in the shell material, to form a solution of the molten shell material and the soluble gas. The solution is atomized to form a multiplicity of separate droplets that are cooled while in free fall. Cooling of a droplet from the outside traps the dissolved gas and forces it to form a gas bubble at the center of the droplet which now forms a gas-filled shell. The shell is reheated and then cooled in free fall, in an environment having a lower pressure than the gas pressure in the shell. This causes expansion of the shell, to form a shell having a small wall thickness compared to its diameter.

Abstract: Hollow shells of high uniformity are formed by emitting liquid through an outer nozzle and gas through an inner nozzle, to form a hollow extrusion, by flowing the gas at a velocity between about 1.3 and 10 times the liquid velocity. The natural breakup rate of the extrusion can be increased to decrease shell size by applying periodic perturbations to one of the materials prior to exiting the nozzles, to a nozzle, or to the extrusion.

Abstract: Systems are described for using multiple closely-packed spheres. In one system for passing fluid, a multiplicity of spheres lie within a container, with all of the spheres having the same outside diameter and with the spheres being closely nested in one another to create multiple interstitial passages of a known size and configuration and smooth walls. The container has an inlet and outlet for passing fluid through the interstitial passages formed between the nested spheres. The small interstitial passages can be used to filter out material, especially biological material such as cells in a fluid, where the cells can be easily destroyed if passed across sharp edges. The outer surface of the spheres can contain a material that absorbs a constitutent in the flowing fluid, such as a particular contamination gas, or can contain a catalyst to chemically react the fluid passing therethrough, the use of multiple small spheres assuring a large area of contact of these surfaces of the spheres with the fluid.

Abstract: The improved, heterogeneous catalysts are in the form of gas-impervious, hollow, thin-walled spheres (10) suitably formed of a shell (12) of metal such as aluminum having a cavity (14) containing a gas at a pressure greater than atmospheric pressure. The wall material may be, itself, catalytic or the catalyst can be coated onto the sphere as a layer (16), suitably platinum or iron, which may be further coated with a layer (18) of activator or promoter. The density of the spheres (30) can be uniformly controlled to a preselected value within .+-.10 percent of the density of the fluid reactant such that the spheres either remain suspended or slowly fall or rise through the liquid reactant.

Abstract: Improved, heterogeneous, refractory catalysts are in the form of gas-impervious, hollow, thin-walled spheres (10) suitable formed of a shell (12) of refractory such as alumina having a cavity (14) containing a gas at a pressure greater than atmospheric pressure. The wall material may be itself catalytic or a catalytically active material coated onto the sphere as a layer (16), suitably platinum or iron, which may be further coated with a layer (18) of activator or promoter. The density of the spheres (30) can be uniformly controlled to a preselected value within .+-.10 percent of the density of the fluid reactant such that the spheres either remain suspended or slowly fall or rise through the liquid reactant.

Abstract: Improved, heterogeneous, refractory catalysts are in the form of gas-impervious, hollow, thin-walled spheres (10) suitable formed of a shell (12) of refractory such as alumina having a cavity (14) containing a gas at a pressure greater than atmospheric pressure. The wall material may be itself catalytic or a catalytically active material coated onto the sphere as a layer (16), suitably platinum or iron, which may be further coated with a layer (18) of activator or promoter. The density of the spheres (30) can be uniformly controlled to a preselected value within .+-.10 percent of the density of the fluid reactant such that the spheres either remain suspended or slowly fall or rise through the liquid reactant.

Abstract: A system is described for forming accurately spherical and centered fluid-filled shells, especially of high melting temperature material. Material which is to form the shells is placed in a solid form in a container, and the material is rapidly heated to a molten temperature to avoid recrystallization and the possible generation of unwanted microbubbles in the melt. Immediately after the molten shells are formed, they drop through a drop tower whose upper end is heated along a distance of at least one foot to provide time for dissipation of surface waves on the shells while they cool to a highly viscous, or just above melting temperature so that the bubble within the shell will not rise and become off centered. The rest of the tower is cryogenically cooled to cool the shell to a solid state.

Abstract: A nozzle assembly is described for use in a system that forms small gas-filled shells, which avoids the need for holding a miniature inner nozzle precisely concentric with a miniature outer nozzle. The outer nozzle has a diameter which is less than about 0.7 millimeter, which results in fluid passing through the nozzle having a progressively greater velocity at locations progressively further from the walls of the outer nozzle across most of the nozzle. This highly variable velocity profile automatically forces gas to the center of the outer nozzle. The end of the inner nozzle, which emits gas, is spaced upstream from the tip of the outer nozzle, to provide a distance along which to center the gas. This self-centering characteristic permits the inner nozzle to be positioned so its axis is not concentric with the axis of the outer nozzle.

Abstract: An apparatus is provided for forming gas-filled spheres of metal, glass or other material, which produces spheres (12) of uniform size and wall thickness in a relatively simple system. The system includes concentric nozzles, including an inner nozzle (18) through which gas flows and and an outer nozzle (20), which jointly define an annular passageway (50) through which a liquid flows. The flow rates are adjusted so that the gas flows at greater velocity than does the liquid, out of their respective nozzles, e.g. three times as great, in order to produce an extrusion (30) which undergoes axisymmetric oscillations resulting in the pinch off into hollow spheres with very uniform spacing. The system is useful not only where gas-filled spheres are required, but also is useful to accurately control the dispensing of solid, liquid, or gaseous materials.

Abstract: The improved, heterogeneous catalysts are in the form of gas-impervious, hollow, thin-walled spheres (10) suitably formed of a shell (12) of metal such as aluminum having a cavity (14) containing a gas at a pressure greater than atmospheric pressure. The wall material may be, itself, catalytic or the catalyst can be coated onto the sphere as a layer (16), suitably platinum or iron, which may be further coated with a layer (18) of activator or promoter. The density of the spheres (30) can be uniformly controlled to a preselected value within .+-.10 percent of the density of the fluid reactant such that the spheres either remain suspended or slowly fall or rise through the liquid reactant.