title: Fabrication and characterization of anisotropic nanofiber scaffolds for advanced drug delivery systems.
abstract: Stimuli-responsive, polymer-based nanostructures with anisotropic compartments are of great interest as advanced materials because they are capable of switching their shape via environmentally-triggered conformational changes, while maintaining discrete compartments. In this study, a new class of stimuli-responsive, anisotropic nanofiber scaffolds with physically and chemically distinct compartments was prepared via electrohydrodynamic cojetting with side-by-side needle geometry. These nanofibers have a thermally responsive, physically-crosslinked compartment, and a chemically-crosslinked compartment at the nanoscale. The thermally responsive compartment is composed of physically crosslinkable poly(N-isopropylacrylamide) poly(NIPAM) copolymers, and poly(NIPAM-co-stearyl acrylate) poly(NIPAM-co-SA), while the thermally-unresponsive compartment is composed of polyethylene glycol dimethacrylates. The two distinct compartments were physically crosslinked by the hydrophobic interaction of the stearyl chains of poly(NIPAM-co-SA) or chemically stabilized via ultraviolet irradiation, and were swollen in physiologically relevant buffers due to their hydrophilic polymer networks. Bicompartmental nanofibers with the physically-crosslinked network of the poly(NIPAM-co-SA) compartment showed a thermally-triggered shape change due to thermally-induced aggregation of poly(NIPAM-co-SA). Furthermore, when bovine serum albumin and dexamethasone phosphate were separately loaded into each compartment, the bicompartmental nanofibers with anisotropic actuation exhibited decoupled, controlled release profiles of both drugs in response to a temperature. A new class of multicompartmental nanofibers could be useful for advanced nanofiber scaffolds with two or more drugs released with different kinetics in response to environmental stimuli.
authors.affiliation: Department of Bionano Engineering, College of Engineering Sciences, Hanyang University, Education Research Industry Cluster at Ansan Campus, Ansan, South Korea.
authors.forename: Ghulam
authors.initials: G
authors.lastname: Jalani
authors.affiliation: Department of Bionano Engineering, College of Engineering Sciences, Hanyang University, Education Research Industry Cluster at Ansan Campus, Ansan, South Korea.
authors.forename: Chan Woo
authors.initials: CW
authors.lastname: Jung
authors.affiliation: Department of Bionano Engineering, College of Engineering Sciences, Hanyang University, Education Research Industry Cluster at Ansan Campus, Ansan, South Korea.
authors.forename: Jae Sang
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Bionano Engineering, College of Engineering Sciences, Hanyang University, Education Research Industry Cluster at Ansan Campus, Ansan, South Korea.
authors.forename: Dong Woo
authors.initials: DW
authors.lastname: Lim
mesh_terms: D000818:Animals; D016880:Anisotropy; D002417:Cattle; D003907:Dexamethasone / Q000031:analogs & derivatives / Q000737:chemistry / Q000493:pharmacokinetics; D016503:Drug Delivery Systems / Q000295:instrumentation*; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000493:pharmacokinetics; D013696:Temperature
chemical_list: D011108:Polymers; D012710:Serum Albumin, Bovine; C004180:dexamethasone 21-phosphate; D003907:Dexamethasone
keywords: actuation; anisotropy; drug delivery; nanofibers; stimuli responsiveness; tissue engineering