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Expired Canadian patentCanada

Polyethylene glycol/polycation block copolymers

CA 2524907 C · Owner: The University Of Tokyo · Inventors: Fukushima, Shigeto; Kataoka, Kazunori; Kanayama, Naoki

CIPO record

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Abstract From the Canadian patent

The invention provides block copolymers formed of poly(ethylene glycol) segments and poly(amino acid derivative) segments having side chains of at least one kind of specific amine residue. The invention also provides polyion complexes of such copolymers with polynucleotides and the like. These block copolymers are useful as carriers for in vivo delivery of active substances such as DNA.

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Filed May 7, 2004 and granted January 31, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 7, 2024.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 7, 2026.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMay 7, 2004
GrantedJanuary 31, 2012
Term endedMay 7, 2024
Patent numberCA 2524907 C
Classification (IPC)C08G69/48 +2 more

Timeline

Timeline From CIPO dates

2005200720092011201320152017201920212023Application filedMay 7, 2004Patent grantedJan 31, 2012Term endedMay 7, 2024

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.