Appeal No. 1999-0623
Application No. 08/316,802
26. A drug delivery composition capable of selective release of said drug
into a preselected physiological environment, comprising:
(1) a synthetic bioelastic polypeptide polymer comprising
repeating elastomeric units selected from the group consisting of
bioelastic pentapeptides, tetrapeptides, and nonapeptides, wherein
said repeating units comprise amino acid residues selected from the
group consisting of hydrohobic amino acid and glycine residues and
wherein said repeating units exist in a conformation having a ß-turn;
and
(2) a drug retained by said polymer;
wherein said polymer is selected to be in a first contraction
state, selected from the group consisting of contracted and relaxed
bioelastomer states, when contacted with a physiological
environment present in a human or animal to whom said composition
is administered and wherein said polymer contains a reactive
functional group that undergoes a reaction, either in the presence of
said physiological environment or when said polymer is transported
by a natural process in said human or animal to a location having a
different physiological environment, to produce a second functional
group, wherein the presence of said second functional group in said
polymer causes said polymer to switch to the other of said
contraction states, thereby making said drug available for release
from said matrix into said preselected physiological environment.
28. The composition of claim 26 wherein said polypeptide comprises
repeating units of the formula aP?OG or VP?d, wherein:
V is a peptide-forming residue of L-valine;
P is a peptide-forming residue of L-proline;
G is a peptide-forming residue of glycine;
I is a peptide-forming residue of L-valine, L-leucine, L-isoleucine, L-
phenylalanine or an ionizable peptide-forming residue selected from
the group consisting of the residues of L-Glu, L-Asp, L-His, L-Lys, L-
Tyr, and other ionizable peptide-forming L-amino acids;
? is a peptide-forming residue of glycine or a peptide-forming residue
of D-Glu, D-Asp, D-His, D-Lys, D-Tyr, and other ionizable peptide-
forming D-amino acids;
O is a peptide-forming residue of L-valine, L-leucine, L-isoleucine, L-
phenylalanine or an ionizable peptide-forming residue selected from
the group consisting of the residues of L-Glu, L-Asp, L-His,
L-Lys, L-Tyr7, and other ionizable peptide-forming L-amino acids;
7 We note the following typographical error in appellants’ appendix of claims. The
term “Try” should be --Tyr --. This typographical error was corrected herein.
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