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Microencapsulation of living tissue and cells

  • US 4,673,566 A
  • Filed: 05/24/1984
  • Issued: 06/16/1987
  • Est. Priority Date: 06/01/1983
  • Status: Expired due to Fees
First Claim
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1. A microcapsule having a diameter of about 500 to about 2000 μ

  • m and suitable for implantation into an animal body, comprising;

    a core comprising one or more viable, healthy, physiologically-active tissue cells capable of ongoing metabolism, anda 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 semi-permeable membrane having a molecular weight cut-off of below about 150,000 daltons,said biocompatible membrane being a hydrogel formed by ionic reaction between a polylysine polymer having a molecular weight from about 10,000 to about 30,000 daltons and a polymeric material bearing negatively-charged groups to provide an outer negatively-charged surface,said polylysine polymer membrane having a durability sufficient to permit said microcapsules to be injected in the animal body and sufficient to maintain said microcapsules in an intact form and to permit said tissue to effect ongoing metabolism when injected into the animal body for a period of time exceeding three months.

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