Abstract: Membranes and methods for making membranes are disclosed. The membranes include a polymeric matrix and a particulate material immobilized within the matrix. The membranes may find particular application in methods and apparatus for removing organic compounds from a biological fluid as part of a pathogen inactivation treatment.

Abstract: The present invention provides a method for preparing submicron-sized particles. The method includes the steps of: (1) providing a multiphase system having an organic phase and an aqueous phase, the organic phase having a pharmaceutically effective compound therein; and (2) sonicating the system to evaporate a portion of the organic phase to cause precipitation of the compound in the aqueous phase and having an average effective particle size of less than about 2 m.

Abstract: A filter for removing leukocytes from blood comprises a filter media enclosed in a housing. The filter media includes a main filter region comprising a porous membrane structure extending between first and second skin surfaces. The porous membrane structure is formed by intersecting cells having a range of diameters. The cells adjacent to the first skin surface have diameters generally smaller than the diameters of the cells adjacent to the second skin surface. The first skin surface includes an open area defined by pores, which are formed by the intersection of cells with the first skin surface. The majority of the open area is defined by pores having a diameter of between about 12 &mgr;m and 28 &mgr;m.

Abstract: Enhanced hydrophobic membranes and methods of making such membranes are disclosed. The membranes are made of a polymer, such as polyvinylidene difluoride coated with a fluorochemical acrylate polymer to enhance hydrophobicity. Membranes of the type described above are made without cross-linking, grafting or in situ polymerization.

Abstract: A filter for removing leukocytes from blood comprises a filter media enclosed in a housing. The filter media includes a main filter region comprising a porous membrane structure extending between first and second skin surfaces. The porous membrane structure is formed by intersecting cells having a range of diameters. The cells adjacent to the first skin surface have diameters generally smaller than the diameters of the cells adjacent to the second skin surface. The first skin surface includes an open area defined by pores, which are formed by the intersection of cells with the first skin surface. The majority of the open area is defined by pores having a diameter of between about 12 &mgr;m and 28 &mgr;m.

Abstract: A filter for removing leukocytes from blood comprises a filter media enclosed in a housing. The filter media includes a main filter region comprising a porous membrane structure extending between first and second skin surfaces. The porous membrane structure is formed by intersecting cells having a range of diameters. The cells adjacent to the first skin surface have diameters generally smaller than the diameters of the cells adjacent to the second skin surface. The first skin surface includes an open area defined by pores, which are formed by the intersection of cells with the first skin surface. The majority of the open area is defined by pores having a diameter of between about 12 &mgr;m and 28 &mgr;m.

Abstract: A device and method for inactivating pathogens in therapeutic fluids with sterilizing radiation in a continuous thin fluid flow arrangement that exhibits radiation dose uniformity for fluids having high optical densities. Radiation dose uniformity is achieved in part through a “carrying” mechanism that moves or carries the fluid, thereby eliminating a channel flow velocity profile where flow volumes near the channel walls run the risk of overexposure to the radiation due to very large residence times within the channel. The device comprises a relatively flat belt chamber (22) connected to a fluid flow through an inlet (24) and an outlet (26) on the belt chamber (22). The belt chamber (22) has a top surface (28) and a bottom surface (30). A radiation permeable plate (32) is disposed adjacent the top surface (28) of the belt chamber (22) and is in contact with the belt chamber (22). A radiation source (42) is provided adjacent to the plate (32) adjacent to a side opposite the belt chamber (22).

Abstract: A membrane capable of sensing gaseous phase ammonia is provided. The membrane includes a hydrophobic membrane layer that has a microporous structure and a pH sensitive dye embedded within the microporous structure such that the membrane is capable of calorimetrically sensing a change in ammonia with a high degree of sensitivity and responsiveness as applied to, for example, a change in ammonia dissolved in a dialysis solution during dialysis therapy.

Abstract: A device and method for inactivating pathogens in therapeutic fluids with sterilizing radiation in a continuous flow arrangement while exhibiting radiation dose uniformity and narrow residence time distribution of the fluid within the device. The device (10) comprises a radiation permeable cylindrical tube (12) having a concentric cylindrical rotor (14) disposed therein, thereby providing a thin gap (16) therebetween. A top plate (18) having a fluid outlet (26) and a bottom plate (20) having a fluid inlet (24) seal the cylindrical tube (12). The inlet (24) and outlet (26) are both in fluid communication with the thin gap (16). A rotor shaft (36) is disposed axially through the cylindrical rotor (14) and is connected to a motor (30). A pump provides fluid flow through the device (10). A radiation source provides sterilizing radiation to the fluid through the cylindrical tube (12).

Abstract: A method and apparatus for filtering suspensions of medical and biological fluids, one aspect of which is separating a suspension comprising at least two types of particles which are differently sized or shaped and in which the first type of particle may be deformable at a relatively lower force and/or faster rate than the second type of particle. A filter member is provided having substantially precisely dimensioned pore sizes, with the pores being dimensioned to allow passage of the first type of suspended particle without distortion or only minimal distortion and passage of the second type of particle only with substantial distortion.

Abstract: An apparatus is disclosed for separating a suspension comprising at least two types of particles which are differently sized or shaped and in which the first type of particle may be deformable at a relatively lower force or faster rate than the second type of particle. A housing is provided having a generally cylindrical inner surface in which is mounted a rotor having a generally cylindrical outer surface. The outer surface of the rotor is spaced from the inner surface of the housing to define a suspension processing gap. A filter membrane is provided on the surface of the rotor or the housing that has pores with substantially precisely dimensioned shapes and sizes to correspond substantially to the shape of the first type of particle, thus allowing passage of the first type of particle and blocking passage of the second type of particle. A suspension is directed into the processing gap for either a selected residence time in contact with the filter membrane and/or at a selected force.

Abstract: Membranes and methods for making membranes are disclosed. The membranes include a polymeric matrix and a particulate material immobilized within the matrix. The membranes may find particular application in methods and apparatus for removing organic compounds from a biological fluid as part of a pathogen inactivation treatment.

Abstract: A method and apparatus for filtering suspensions of medical and biological fluids, one aspect of which is separating a suspension comprising at least two types of particles which are differently sized or shaped and in which the first type of particle may be deformable at a relatively lower force and/or faster rate than the second type of particle. A filter member is provided having substantially precisely dimensioned pore sizes, with the pores being dimensioned to allow passage of the first type of suspended particle without distortion or only minimal distortion and passage of the second type of particle only with substantial distortion.

Abstract: Membranes and methods for making membranes are disclosed. The membranes include a polymeric matrix and a particulate material immobilized within the matrix. The membranes may find particular application in methods and apparatus for removing organic compounds from a biological fluid as part of a pathogen inactivation treatment.

Abstract: A permeable structure forms a chamber to hold living cells. The structure includes a first permeable region surrounding at least a portion of the chamber having a conformation that, when implanted in host tissue, substantially blocks penetration of host cells into the chamber while permitting solute transport. The structure also includes a second permeable region overlying the first permeable region having a conformation that, when implanted in host tissue, forms a permeable interface with host tissue that permits solute transport. A third permeable region is located between the first and second permeable regions. The third region comprises a solution of polymer material formed in place between the first and second permeable regions. The third permeable region bonds the first and second permeable regions together. The third permeable region also has a conformation that, when implanted in host tissue, permits solute transport between the first and second permeable regions.

Abstract: A method correlates average fiber diameter with performance for a complex filtration media comprising a matrix of fibers having a fibrillated component with a diameter so small (e.g., less than 0.01 microns), that cannot be physically measured with accuracy. The method manufactures a selected matrix, derives the number average diameter of the fibers according to prescribed steps, some of which do not require actual physical measurements, and observes a performance characteristic. The method repeats the foregoing steps for different matrixes, yielding different number average diameters. The method expresses change in the selected performance characteristic as a function of change in number average diameter of the matrices.

Abstract: Polymer membrane structures are microfabricated from polyimide film by lithography or etching. The microfabricated structures have systematically varied dimensions and geometries conducive to implanting in host tissue and the promotion, when implanted, of new vascular structures.

Abstract: Improved Implant assemblies and methodologies provide immuno-protection for implanted allografts, xenografts, and isografts. The assemblies and methodologies establish an improved chamber for holding the implanted cells. The chambers include first and second wall elements and an intermediate sealing element. The first and second wall elements overlie an open area in the sealing member to form a chamber for holding cells for implantation. A sealed region is created between the wall elements and the sealing element body to close the chamber. In one arrangement, the sealed region is created by means of a sonic weld made while the implanted cells are present in the chamber. In another arrangement, the sealed region is created by means of applying an external force to compress the peripheral edges of the wall elements and the sealing element together while the implanted cells are present in the chamber.

Abstract: Improved Implant assemblies and methodologies provide immuno-protection for implanted allografts, xenografts, and isografts. The assemblies and methodologies establish an improved chamber for holding the implanted cells. The chambers include first and second wall elements and an intermediate sealing element. The first and second wall elements overlie an open area in the sealing member to form a chamber for holding cells for implantation. A sealed region is created between the wall elements and the sealing element body to close the chamber. In one arrangement, the sealed region is created by means of a sonic weld made while the implanted cells are present in the chamber. In another arrangement, the sealed region is created by means of applying an external force to compress the peripheral edges of the wall elements and the sealing element together while the implanted cells are present in the chamber.

Abstract: Provided, is a membrane unit which can sealably accommodate a variable plurality of stacked planar membrane elements.