title: Robocasting nanocomposite scaffolds of poly(caprolactone)/hydroxyapatite incorporating modified carbon nanotubes for hard tissue reconstruction.
abstract: Nanocomposite scaffolds with tailored 3D pore configuration are promising candidates for the reconstruction of bone. Here we fabricated novel nanocomposite bone scaffolds through robocasting. Poly(caprolactone) (PCL)-hydroxyapatite (HA) slurry containing ionically modified carbon nanotubes (imCNTs) was robotic-dispensed and structured layer-by-layer into macrochanneled 3D scaffolds under adjusted processing conditions. Homogeneous dispersion of imCNTs (0.2 wt % relative to PCL-HA) was achieved in acetone, aiding in the preparation of PCL-HA-imCNTs slurry with good mixing property. Incorporation of imCNTs into PCL-HA composition significantly improved the compressive strength and elastic modulus of the robotic-dispensed scaffolds (~1.5-fold in strength and ~2.5-fold in elastic modulus). When incubated in simulated body fluid (SBF), PCL-HA-imCNT nanocomposite scaffold induced substantial mineralization of apatite in a similar manner to the PCL-HA scaffold, which was contrasted in pure PCL scaffold. MC3T3-E1 cell culture on the scaffolds demonstrated that cell proliferation levels were significantly higher in both PCL-HA-imCNT and PCL-HA than in pure PCL, and no significant difference was found between the nanocomposite scaffolds. When the PCL-HA-imCNT scaffold was implanted into a rat subcutaneous tissue for 4 weeks, soft fibrous tissues with neo-blood vessels formed well in the pore channels of the scaffolds without any significant inflammatory signs. Tissue reactions in PCL-HA-imCNT scaffold were similar to those in PCL-HA scaffold, suggesting incorporated imCNT did not negate the beneficial biological roles of HA. While more long-term in vivo research in bone defect models is needed to confirm clinical availability, our results suggest robotic-dispensed PCL-HA-imCNT nanocomposite scaffolds can be considered promising new candidate matrices for bone regeneration.
authors.affiliation: Department of Nanobiomedical Science and WCU Research Center, Dankook University, South Korea.
authors.forename: Biligzaya
authors.initials: B
authors.lastname: Dorj
authors.forename: Jong-Eun
authors.initials: JE
authors.lastname: Won
authors.forename: Joong-Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Seong-Jun
authors.initials: SJ
authors.lastname: Choi
authors.forename: Ueon Sang
authors.initials: US
authors.lastname: Shin
authors.forename: Hae-Won
authors.initials: HW
authors.lastname: Kim
mesh_terms: D000818:Animals; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D019245:Compressive Strength / Q000187:drug effects; D017886:Durapatite / Q000494:pharmacology*; D007477:Ions; D051379:Mice; D008970:Molecular Weight; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D011091:Polyesters / Q000494:pharmacology*; D051381:Rats; D012371:Robotics / Q000379:methods*; D012996:Solutions; D040521:Subcutaneous Tissue / Q000187:drug effects; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D007477:Ions; D037742:Nanotubes, Carbon; D011091:Polyesters; D012996:Solutions; D014867:Water; C016240:polycaprolactone; D017886:Durapatite