Preparation of small bio-compatible microspheres
AssigneeCalifornia Institute of Technology
InventorsAlan Rembaum, Shiao-Ping S. Yen, William J. Dreyer
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Abstract
Small, round, bio-compatible microspheres capable of covalently bonding proteins and having a uniform diameter below about 3500 A are prepared by substantially instantaneously initiating polymerization of an aqueous emulsion containing no more than 35% total monomer including an acrylic monomer substituted with a covalently bondable group such a hydroxyl, amino or carboxyl and a minor amount of a cross-linking agent.
Claims14
An aqueous emulsion polymerization composition for forming a suspension of discrete polymeric beads having a diameter below 3500 A containing an effective amount of at least 0.003 percent to 0.1 percent by weight of a free radical catalyst, a surface active agent and not more than 35% by weight of an ethylenically unsaturated monomer mixture comprising in percent by weight:
- 25-50% by weight of a freely water-soluble monoethylenically unsaturated monomer substituted with a covalent bonding group selected from carboxyl, amino or hydroxyl;
- 5-20% by weight of a polyunsaturated cross-linking agent;
- and
- 40-70% by weight of at least one sparingly, water-soluble, ethylenically unsaturated, second monomer having hydrophobic characteristics.
Dependencies are inferred from the claim text.