title: Coaxial electrospinning of (fluorescein isothiocyanate-conjugated bovine serum albumin)-encapsulated poly(epsilon-caprolactone) nanofibers for sustained release.
abstract: As an aim toward developing biologically mimetic and functional nanofiber-based tissue engineering scaffolds, we demonstrated the encapsulation of a model protein, fluorescein isothiocyanate-conjugated bovine serum albumin (fitcBSA), along with a water-soluble polymer, poly(ethylene glycol) (PEG), within the biodegradable poly(epsilon-caprolactone) (PCL) nanofibers using a coaxial electrospinning technique. By variation of the inner flow rates from 0.2 to 0.6 mL/h with a constant outer flow rate of 1.8 mL/h, fitcBSA loadings of 0.85-2.17 mg/g of nanofibrous membranes were prepared. Variation of flow rates also resulted in increases of fiber sizes from ca. 270 nm to 380 nm. The encapsulation of fitcBSA/PEG within PCL was subsequently characterized by laser confocal scanning microscopy, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) analysis. In vitro release studies were conducted to evaluate sustained release potential of the core-sheath-structured composite nanofiber PCL-r-fitcBSA/PEG. As a negative control, composite nanofiber PCL/fitcBSA/PEG blend was prepared from a normal electrospinning method. It was found that core-sheath nanofibers PCL-r-fitcBSA/PEG pronouncedly alleviated the initial burst release for higher protein loading and gave better sustainability compared to that of PCL/fitcBSA/PEG nanofibers. The present study would provide a basis for further design and optimization of processing conditions to control the nanostructure of core-sheath composite nanofibers and ultimately achieve desired release kinetics of bioactive proteins (e.g., growth factors) for practical tissue engineering applications.
authors.affiliation: Division of Bioengineering, Department of Mechanical Engineering, and Nanoscience and Nanotechnology Initiative, National University of Singapore, 9 Engineering Drive 1, Singapore 117576. biezyz@nus.edu.sg
authors.forename: Y Z
authors.initials: YZ
authors.lastname: Zhang
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.forename: Y
authors.initials: Y
authors.lastname: Feng
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: C T
authors.initials: CT
authors.lastname: Lim
authors.forename: S
authors.initials: S
authors.lastname: Ramakrishna
mesh_terms: D000818:Animals; D002417:Cattle; D004563:Electrochemistry; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors
chemical_list: D011091:Polyesters; C016240:polycaprolactone; D012710:Serum Albumin, Bovine; D016650:Fluorescein-5-isothiocyanate