J. Cappello et al., IN-SITU SELF-ASSEMBLING PROTEIN POLYMER GEL SYSTEMS FOR ADMINISTRATION, DELIVERY, AND RELEASE OF DRUGS, Journal of controlled release, 53(1-3), 1998, pp. 105-117
Sequential block copolymers consisting of tandem repetition of amino a
cids have been constructed and genetically produced based on the natur
al repeating structures of silk and elastin protein. Combinations of s
ilklike and elastinlike amino acid sequence blocks in a high molecular
weight protein polymer are used to confer properties similar to those
observed with hard block and soft block segmented polyurethanes. A ce
rtain subset of these silk-elastinlike protein compositions, termed Pr
oLastins, will undergo an irreversible solution to gel transition in p
hysiological, aqueous solution. The transition occurs over time and ca
n be controlled by temperature, solution conditions, and additives whi
ch either prevent or promote hydrogen bond-mediated chain crystallizat
ion. The process involves no covalent crosslinking. Characterization o
f the gelling properties of various ProLastin compositions and their a
bility to release compounds which are incorporated directly into the g
els are presented. (C) 1998 Elsevier Science B.V.