title: Controlled release from fibers of polyelectrolyte complexes.
abstract: Controlled release systems for delicate compounds, such as proteins, often suffer the drawbacks of decreased bioactivity and low encapsulation efficiency. This study introduces the concept of producing drug-loaded fibers from interfacial polyelectrolyte complexation. Chitosan-alginate fibers were produced by pulling from the interface between two polyelectrolyte solutions at room temperature. Depending on the component properties, the release time of encapsulated components from these fibers can range from hours to weeks. Dexamethasone was completely released within 2 h, whereas charged compounds such as BSA, PDGF-bb, and avidin showed sustained release for 3 weeks. The fibers were able to release PDGF-bb in a steady fashion for over 3 weeks without an initial burst. Furthermore, the bioactivity of PDGF-bb was retained over this period. Release kinetics could be controlled by the inclusion of heparin, which contains specific binding sites for various growth factors. By varying the alginate/heparin ratios in the anionic polyelectrolyte solution, the release of PDGF-bb could be significantly altered. In this study, interfacial polyelectrolyte complexation has been demonstrated to be a promising technique for producing drug-loaded fibers with high encapsulation efficiency, sustained release kinetics, and capacity to retain the bioactivity of the encapsulants.
authors.affiliation: Department of Biomedical Engineering, The Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA.
authors.forename: I-Chien
authors.initials: IC
authors.lastname: Liao
authors.forename: Andrew C A
authors.initials: AC
authors.lastname: Wan
authors.forename: Evelyn K F
authors.initials: EK
authors.lastname: Yim
authors.forename: Kam W
authors.initials: KW
authors.lastname: Leong
mesh_terms: D000464:Alginates / Q000008:administration & dosage*; D000818:Animals; D001360:Avidin / Q000008:administration & dosage / Q000737:chemistry; D000077214:Becaplermin; D048271:Chitosan / Q000008:administration & dosage*; D003907:Dexamethasone / Q000008:administration & dosage / Q000737:chemistry; D016503:Drug Delivery Systems; D020723:Glucuronic Acid / Q000008:administration & dosage*; D006603:Hexuronic Acids / Q000008:administration & dosage*; D051379:Mice; D041681:NIH 3T3 Cells; D010982:Platelet-Derived Growth Factor / Q000008:administration & dosage / Q000737:chemistry; D020574:Proto-Oncogene Proteins c-sis; D012710:Serum Albumin, Bovine / Q000008:administration & dosage / Q000737:chemistry
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D001360:Avidin; D000077214:Becaplermin; D012710:Serum Albumin, Bovine; D003907:Dexamethasone; D020723:Glucuronic Acid; D048271:Chitosan