Other

Michael H May

Yu-Ling Cheng

Michael Vivian Sefton

Hai-Hui Lin

Julia E Babensee

John L Semple

The invention relates to the use of a thermal reversible gel, such as a copolymer composition, as a biological filler or implant. The gel has a semi-solid form at body temperature, but upon cooling to a temperature below a threshold level, the gel is liquefied and can be re-shaped, re-sized, manipulated or removed from the body. The gel may be used as a subcutaneous implant, a biological filler, joint or tissue spacer, for wrinkle filling or other cosmetic implants, as a soft-tissue replacement for reconstructive surgery, or as a barrier within the lumen of a biological structure, such as a blood vessel. The implant may be used to provide reversible birth control by providing, for example, a reversible barrier to the cervix or a reversible blockage of the lumen of the vas deferens.

Thermally reversible implant and filler

An angiogenic material is provided which promotes extensive vascularization when implanted in animal tissue. The angiogenic material contains a biocompatible polymer and a vascularizing polymerizable compound capable of forming anions. The polymer may be a polyacrylate, and the polymerizable compound includes compounds having ionizable groups selected from sulfates, sulfonic acid groups and carboxyl groups. These compounds include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, vinylsulfonic acid and vinylacetic acid. The angiogenic material is preferably used in microcapsule coatings and microspheres for implantation in animals. In microcapsules, the angiogenic material promotes better exchange of nutrients, waste products and cellular products between encapsulated cells and the circulatory system of the host animal. Microspheres containing the angiogenic material may be used to assist in recovery of ischemic heart muscle by injection of the microspheres into the heart muscle or blood vessels serving the ischemic area. Also provided is a method of forming small microcapsules and microspheres by passing cell aggregates or air bubbles through layers of a density gradient to obtain microcapsules or microspheres having a diameter no greater than 500 &mgr;m that contain cells or do not contain cells. When cells are present, a semi-permeable coating of the angiogenic material surrounds the cells.

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Brantford, Canada

Michael H May