Microcapsule composition suitable for cardiovascular injection
AssigneeConnaught Laboratories Limited
InventorsMartin Hommel, Anthony Mein-Fang Sun, Mattheus F. A. Goosen
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Abstract
Perfectly spherical, smooth and uniform microcapsules, which may contain living cells, are produced having a diameter less than 700 .mu.m, e.g. 150 to about 500 microns, by employing an electrostatic droplet generator. A droplet is suspended from a pointed source, such as a needle, and is charged with high static voltage. A collecting vessel or ring device is charged with opposing polarity and attracts the droplet When a voltage potential threshold is passed, the droplet moves from the source to the collecting vessel. The voltage pulse height, pulse frequency and length, and extrusion rate of the droplet are adjustable so that predetermined sizes of droplets may be repeatedly generated and collected.
Claims18
A composition of spherical, smooth and uniform microcapsules suitable for cardiovascular injection into an animal body, said microcapsules comprising:
- a core comprising one or more viable, healthy, physiologically-active tissue cells capable of on going metabolism and an aqueous medium of nutrients sufficient to maintain said tissue cells and allow normal metabolism thereof, and
- a biocompatible semi-permeable membrane surrounding and enclosing said core, said semi-permeable membrane being permeable to tissue nutrients and metabolic products produced by the tissue but impermeable to immune system proteins,
- said membrane comprising ionically-interacted biocompatible materials and having a negatively-charged outer surface, said microcapsules having a diameter consisting essentially of about 150 to about 500 microns.
A method of controlling blood sugar levels in diabetic animals, which comprises:
- cardiovascularly injecting an effective amount of biocompatible, spherical and smooth microcapsules each having a diameter consisting essentially of from about 150 to about 500 microns,
- said microcapsules each having (1) a core comprising one or more viable, healthy, physiologically-active islets of Langerhans capable of on-going metabolism to produce insulin and a medium sufficient to maintain said islets of Langerhans and allow normal metabolism thereof and (2) a biocompatible semi-permeable membrane surrounding and enclosing said core, said semi-permeable membrane being permeable to nutrients for the islets and insulin produced thereby but impermeable to immune system proteins, said membrane comprising ionically-interacted biocompatible materials and having a negatively-charged outer surface.
Dependencies are inferred from the claim text.