title: Polymer-Enriched 3D Graphene Foams for Biomedical Applications.
abstract: Graphene foams (GFs) are versatile nanoplatforms for biomedical applications because of their excellent physical, chemical, and mechanical properties. However, the brittleness and inflexibility of pristine GF (pGF) are some of the important factors restricting their widespread application. Here, a chemical-vapor-deposition-assisted method was used to synthesize 3D GFs, which were subsequently spin-coated with polymer to produce polymer-enriched 3D GFs with high conductivity and flexibility. Compared to pGF, both poly(vinylidene fluoride)-enriched GF (PVDF/GF) and polycaprolactone-enriched GF (PCL/GF) scaffolds showed improved flexibility and handleability. Despite the presence of the polymers, the polymer-enriched 3D GF scaffolds retained high levels of electrical conductivity because of the presence of microcracks that allowed for the flow of electrons through the material. In addition, polymer enrichment of GF led to an enhancement in the formation of calcium phosphate (Ca-P) compounds when the scaffolds were exposed to simulated body fluid. Between the two polymers tested, PCL enrichment of GF resulted in a higher in vitro mineralization nucleation rate because the oxygen-containing functional group of PCL had a higher affinity for Ca-P deposition and formation compared to the polar carbon-fluorine (C-F) bond in PVDF. Taken together, our current findings are a stepping stone toward future applications of polymer-enriched 3D GFs in the treatment of bone defects as well as other biomedical applications.
authors.affiliation: †Residues and Resource Reclamation Centre (R3C), Nanyang Environment and Water Research Institute (NEWRI), Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore.
authors.forename: Jun Kit
authors.initials: JK
authors.lastname: Wang
authors.forename: Gordon Minru
authors.initials: GM
authors.lastname: Xiong
authors.affiliation: ⊥Graphene Research Center, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore.|||Department of Physics, National University of Singapore, Singapore 117542, Singapore.
authors.forename: Minmin
authors.initials: M
authors.lastname: Zhu
authors.affiliation: ⊥Graphene Research Center, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore.|||Department of Physics, National University of Singapore, Singapore 117542, Singapore.
authors.forename: Barbaros
authors.initials: B
authors.lastname: Özyilmaz
authors.affiliation: ⊥Graphene Research Center, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore.|||Department of Physics, National University of Singapore, Singapore 117542, Singapore.
authors.forename: Antonio Helio
authors.initials: AH
authors.lastname: Castro Neto
authors.affiliation: ▽School of Biological Sciences, Nanyang Technological University, 60 Nanyang Avenue, Singapore 637551, Singapore.|¶Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, A*STAR, Singapore 138673, Singapore.
authors.forename: Nguan Soon
authors.initials: NS
authors.lastname: Tan
authors.affiliation: ⊥Graphene Research Center, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore.
authors.forename: Cleo
authors.initials: C
authors.lastname: Choong
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis*; D001826:Body Fluids / Q000737:chemistry*; D002130:Calcium Phosphates / Q000138:chemical synthesis*; D004553:Electric Conductivity; D005740:Gases / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D008422:Materials Testing; D011091:Polyesters / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D066330:Printing, Three-Dimensional; D005465:Fluorocarbon Polymers
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; D005740:Gases; D006108:Graphite; D011091:Polyesters; D011145:Polyvinyls; C024865:polyvinylidene fluoride; D005465:Fluorocarbon Polymers; C016240:polycaprolactone; C020243:calcium phosphate
keywords: biomineralization; chemical vapor deposition (CVD); graphene foam (GF); poly(vinylidene fluoride) (PVDF); polycaprolactone (PCL)