Hyaluronate-heparin conjugate gels for the delivery of basic fibroblast growth factor (FGF-2).
The stability and activity of recombinant growth factors administered locally for the repair of damaged tissue can be directly influenced by the physical structure and chemical composition of the delivery matrix. This study describes a novel basic fibroblast growth factor-2 (FGF-2) delivery system synthesized by the conjugation of a structure-stabilizing polymer, hyaluronate (HA), with a sulfated glycosaminoglycan, heparin (HP), that has inherent specific binding sites for members of the FGF family. The biopolymers were formed via stable amine or labile imine bonds by coupling amine-modified HA with oxidized heparin. The addition of recombinant human FGF-2 resulted in the rapid binding of FGF-2 to the heparin segment of the hyaluronate-heparin (HAHP) conjugate. The FGF-2 was released in vitro from the imine-bonded (HAHPi) gels in the form of FGF-2-heparin complexes through the hydrolysis of the imine bonds. In contrast, the release of growth factor from the more stable amine-bonded (HAHPa) gels required treatment with free heparin or enzymatic digestion of the hyaluronate segment. Functional analysis of the released FGF-2 showed that the HAHP conjugate gels increased both the stability and activity of the growth factor.
Liu
Lin-Shu
LS
Orquest, Inc., Mountain View, California 94043, USA. athompso@orquest.com
Ng
Chee-Keng
CK
Thompson
Andrea Y
AY
Poser
James W
JW
Spiro
Robert C
RC
D016475:3T3 Cells; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D004337:Drug Carriers / Q000138:chemical synthesis; D016503:Drug Delivery Systems / Q000379:methods*; D016222:Fibroblast Growth Factor 2 / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000494:pharmacology; D006493:Heparin / Q000737:chemistry*; D006820:Hyaluronic Acid / Q000737:chemistry*; D020100:Hydrogels / Q000138:chemical synthesis*; D007700:Kinetics; D051379:Mice; D012038:Regeneration; D014945:Wound Healing
D004337:Drug Carriers; D020100:Hydrogels; D016222:Fibroblast Growth Factor 2; D006820:Hyaluronic Acid; D006493:Heparin