Biocompatible polymerization accelerators - Patents

Agent: Paul L. Weaver Kagan Binder, PLLC - Stillwater, MN, US
Inventors: Dale G. Swan, Stephen J. Chudzik, Ronald F. Ofstead
Class: 424078300 (USPTO), A61K031/785 (Intl Class)
#20050112086
05/26/05

The present invention provides method and materials for forming a polymeric matrix having improved biocompatible properties. A polymerization accelerator is provided that includes an N-vinyl group and a biocompatible functional group. The polymerization accelerator is particularly useful for the polymerization of macromers, which can be used to form biocompatible polymeric coatings on the surface of biological materials, such as cells and tissue.
FIELD OF THE INVENTION
[0001] The present invention relates to compounds and compositions that can be used to form polymeric matrices useful with biological systems. More particularly, the invention relates to compounds that can promote the formation of the polymeric matrices and provide biocompatible features to these matrices.
SUMMARY OF THE INVENTION
[0013] In one aspect, the invention provides compositions that include polymerizable material and a polymerization accelerator having a biocompatible functional group. Polymerization accelerators described herein are able to react with the polymerizable material to form a polymeric matrix having biocompatible properties. Therefore, the invention also provides biocompatible polymeric matrices formed by incorporation of the polymerization accelerator into the polymerizable material. In particular, the polymerization accelerators described herein can promote the formation of a polymeric matrix from a composition containing polymerizable polymers (macromers).
[0014] The compositions that include polymerizable material and a polymerization accelerator can also include a polymerization initiator. Particularly useful polymerization initiators include a photoinitiator group, such as a long-wave ultra violet- or visible light-activatable molecule. The composition can also include a macromer, as indicated, wherein preferred macromers are water-soluble macromers. The compositions can also include an acceptor or reductant.
[0015] The polymerization accelerator can include any of the following biocompatible functional groups: phosphonate (PO.sub.3.sup.-), sulfonate (SO.sub.3.sup.-), carboxylate (COO.sup.-), hydroxyl (OH), albumin binding moieties, and phospholipid moieties. A preferred biocompatible functional group is a sulfonate group.
[0016] In another aspect, the polymerization accelerator includes an N-vinyl group. According to the invention, it has been discovered that, in particular, polymerization accelerators having an N-vinyl group are able to promote formation of a polymeric matrix from a composition that includes macromers. One group of polymerization accelerators described herein has an N-vinyl group and a carbonyl carbon. Preferred polymerization accelerators include an N-vinyl amide group. The N-vinyl group can be a part of a heterocyclic ring structure in some cases.
[0017] In another aspect, the invention provides polymerization accelerators that have a biocompatible functional group and an N-vinyl group. In particular polymerization accelerators having an N-vinyl amide and a sulfonate biocompatible functional group are described herein.
[0018] In another aspect, the invention provides a method for forming a biocompatible polymeric matrix. The method includes the steps of: (a) placing in contact with a surface at least the following materials: (i) a polymerization accelerator comprising a biocompatible functional group; (ii) a polymerizable compound; and (iii) a polymerization initiator; and (b) activating the polymerization initiator to promote formation of a biocompatible polymeric matrix on the surface. The method is particularly useful for coating biological surfaces, such as the surface or cells or groups of cells, for example tissue. The biocompatible functional group provided by the polymerization accelerator can improve the biocompatibility of the surface having the formed polymeric matrix.
[0019] More specifically, the polymerization accelerator of the invention can be used in a method for encapsulating cells. The method can include the steps of: (a) placing in contact with one or more cells at least the following materials: (i) a polymerization accelerator comprising a biocompatible functional group; (ii) a polymerizable compound; and (iii) a polymerization initiator; and (b) activating the polymerization initiator to promote formation of a biocompatible polymeric matrix on the one or more cells. Cells, such as endocrine cells from the pancreas, can be encapsulated with a matrix of polymeric material formed using the polymerization accelerator of the invention. The encapsulated cells can be introduced into a subject for therapeutic purposes.
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