title: Biodegradable polyphosphazene-nanohydroxyapatite composite nanofibers: scaffolds for bone tissue engineering.
abstract: Bone is a natural composite comprised of hierarchically arranged collagen fibrils, hydroxyapatite and proteoglycans in the nanometer scale. This preliminary study reports the fabrication of biodegradable poly[bis(ethyl alanato)phosphazene]-nanohydroxyapatite (PNEA-nHAp) composite nanofiber matrices via electrospinning. Binary solvent compositions of THF and ethanol were used as a spinning solvent to attain better nanohydroxyapatite dispersibility in PNEA solution. These nanocomposites were characterized for morphology, nHAp distribution and content using spectroscopy and gravimetric estimations. Composite nanofibers fabricated in the diameter range of 100-310 nm could encapsulate 20-40 nm nHAp crystals. A better composite nanofiber yield was obtained for 50% (w/w) nHAp experimental loadings. Incremental experimental loading beyond 60% (w/w) hindered electrospinning due to polymer-nHAp phase separation. Composites nanofibers had a rougher surface and nodules along the length of the fibers suggesting nHAp encapsulation. Further, characterization via energy dispersive X-ray spectroscopy and X-ray mapping confirmed the nHAp encapsulation. Providing cells with a natural bone like environment with a fibrillar structure and natural hydroxyapatite can enhance bone tissue regeneration/repair.
authors.affiliation: Department of Chemistry, University of Virginia, Virginia 22903, USA.
authors.forename: Subhabrata
authors.initials: S
authors.lastname: Bhattacharyya
authors.forename: Sangamesh G
authors.initials: SG
authors.lastname: Kumbar
authors.forename: Yusuf M
authors.initials: YM
authors.lastname: Khan
authors.forename: Lakshmi S
authors.initials: LS
authors.lastname: Nair
authors.forename: Anurima
authors.initials: A
authors.lastname: Singh
authors.forename: Nick R
authors.initials: NR
authors.lastname: Krogman
authors.forename: Paul W
authors.initials: PW
authors.lastname: Brown
authors.forename: Harry R
authors.initials: HR
authors.lastname: Allcock
authors.forename: Cato T
authors.initials: CT
authors.lastname: Laurencin
mesh_terms: D020341:Absorbable Implants; D018786:Bone Substitutes / Q000138:chemical synthesis*; D019245:Compressive Strength; D003460:Crystallization / Q000379:methods; D017886:Durapatite / Q000737:chemistry*; D055119:Elastic Modulus; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D050997:Nanomedicine / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D009943:Organophosphorus Compounds / Q000737:chemistry*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D013499:Surface Properties; D013718:Tensile Strength; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D018786:Bone Substitutes; D046911:Macromolecular Substances; D009943:Organophosphorus Compounds; D011108:Polymers; C108974:poly(phosphazene); D017886:Durapatite