Abstract: The invention relates to a method for the preparation of microencapsulated colloidal systems such as liposomes, i.e., microspheres which comprise colloidal systems. These microencapsulated colloidal systems can be used as controlled release systems for the delivery of active ingredients in in vivo and in vitro applications. A method is provided in which the colloidal systems are added to a phase which comprises a water soluble crosslinkable polymer followed by formation of microspheres.

Abstract: A process for the preparation of a controlled release system, comprising forming of an aqueous two-phase system form at least two water soluble polymers which are incompatible in solution, at least one of these polymers being cross-linkable, the cross-linkable polymer phase being emulsified in the other polymer phase; adding at least one relesable compound which is soluble in the cross-linked polymer phase in the aqueous solution, allowing the releasable compound to diffuse in the cross linkable polymer phase; cross-linking the cross-linkable polymer before or after the releasable compound is added, preferably to a degree that the pores in the cross-liked structure are substantially smaller than the particle size of the releasable compound; and separating the cross-linked structures enclosing the release able compound from the other phase. Further, the invention relates to microspheres, at least 80 wt.

Abstract: Water soluble polymers or polymeric hydrogels are used to encapsulate antigen to form vaccines. The antigen is mixed with a polymer solution, microparticles are formed of the polymer and antigen, and, optionally, the polymer is crosslinked to form a stable microparticle. Preferred polymers are alginate and polyphospazenes, and mixtures thereof. Microparticles can be administered parenterally or mucosally. For oral delivery, the microparticles are preferably fifteen microns or less in diameter, and adhere to the mucosal lining of the gastointestinal tract, increasing uptake by the reticuloendothelium.

Abstract: The present invention relates to a synthetic transfection or blocking system comprising as a carrier a cationic, water soluble or water dispersable polyacrylate, a polyacrylamide, a poly(C.sub.1-6 alkyl)acrylate or poly(C.sub.1-6 alkyl)acrylamide. In addition, it relates to a method for introducing DNA fragments in target cells, comprising contacting these DNA fragments with a polyacrylate, a polyacrylamide, a poly(C.sub.1-6 alkyl)acrylate or poly(C.sub.1-6 alkyl)acrylamide, which is at least partially substituted with cationic substituents and subsequently contacting the obtained transfection system with target cells. Finally, the invention involves the use of a polyacrylate, a polyacrylamide, a poly(C.sub.1-6 alkyl)acrylate or poly(C.sub.1-6 alkyl)acrylamide, which is at least partially substituted with cationic substituents as a DNA carrier system.

Abstract: The present invention to a synthetic transfection system comprising as a carrier a cationic, water dispersible polyphosphazene. In addition, it relates to a method for introducing DNA fragments in target cells, comprising contacting these DNA fragments with a polyphosphazene which is at least partially substituted with cationic substituents and subsequently contacting the obtained transfection system with target cells. Finally, the invention involves the use of a polyphosphazene which is at least partially substituted with cationic substituents as a transfection vehicle.