TY - JOUR
T1 - Polylactones 57. Biodegradable networks based on A - B - A triblock segments containing poly(ethylene glycol)s - Syntheses and drug release properties
AU - Kricheldorf, Hans R.
AU - Fechner, Björn
AU - Shikanov, Ariella
AU - Domb, Abraham
PY - 2003/7
Y1 - 2003/7
N2 - Condensation of Bu2Sn(OMe)2 with poly(ethylene glycol)s yielded macrocyclic tin alkoxides which were, in turn, used as cyclic initiators for the ring-expansion polymerization of ε-caprolactone, D,L-lactide, or trimethylene carbonate. The resulting cyclic triblock copolymers were in situ cross-linked with trimesoyl chloride. The lengths of the A-B-A triblock segments were varied via the monomer-initiator ratio (M/I) or via the lengths of the poly(ethylene glycol)s. After extraction with CH2Cl2, the isolated networks were characterized by 1H NMR spectroscopy, DSC measurements, and swelling experiments. The release of dexamethasone and 5-fluorouracil from two triblock networks was studied in physiological buffer solutions at 37 °C over a period of several weeks. A strong initial burst was found in all cases. Only a weak initial burst and a more continuous release was observed when networks of random L-lactide/ε-caprolactone copolymers were studied under the same conditions.
AB - Condensation of Bu2Sn(OMe)2 with poly(ethylene glycol)s yielded macrocyclic tin alkoxides which were, in turn, used as cyclic initiators for the ring-expansion polymerization of ε-caprolactone, D,L-lactide, or trimethylene carbonate. The resulting cyclic triblock copolymers were in situ cross-linked with trimesoyl chloride. The lengths of the A-B-A triblock segments were varied via the monomer-initiator ratio (M/I) or via the lengths of the poly(ethylene glycol)s. After extraction with CH2Cl2, the isolated networks were characterized by 1H NMR spectroscopy, DSC measurements, and swelling experiments. The release of dexamethasone and 5-fluorouracil from two triblock networks was studied in physiological buffer solutions at 37 °C over a period of several weeks. A strong initial burst was found in all cases. Only a weak initial burst and a more continuous release was observed when networks of random L-lactide/ε-caprolactone copolymers were studied under the same conditions.
UR - http://www.scopus.com/inward/record.url?scp=0043199408&partnerID=8YFLogxK
U2 - 10.1021/bm0300148
DO - 10.1021/bm0300148
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C2 - 12857078
AN - SCOPUS:0043199408
SN - 1525-7797
VL - 4
SP - 950
EP - 955
JO - Biomacromolecules
JF - Biomacromolecules
IS - 4
ER -