PDLLA honeycomb-like scaffolds with a high loading of superhydrophilic graphene/multi-walled carbon nanotubes promote osteoblast in vitro functions and guided in vivo bone regeneration

Edmundo Silva; Luana Marotta Reis de Vasconcellos; Bruno V M Rodrigues; Danilo Martins Dos Santos; Sergio P Campana-Filho; Fernanda Roberta Marciano; Thomas J Webster; Anderson Oliveira Lobo

doi:10.1016/j.msec.2016.11.075

PDLLA honeycomb-like scaffolds with a high loading of superhydrophilic graphene/multi-walled carbon nanotubes promote osteoblast in vitro functions and guided in vivo bone regeneration

Mater Sci Eng C Mater Biol Appl. 2017 Apr 1:73:31-39. doi: 10.1016/j.msec.2016.11.075. Epub 2016 Nov 23.

Authors

Edmundo Silva¹, Luana Marotta Reis de Vasconcellos², Bruno V M Rodrigues³, Danilo Martins Dos Santos⁴, Sergio P Campana-Filho⁴, Fernanda Roberta Marciano⁵, Thomas J Webster⁶, Anderson Oliveira Lobo⁷

Affiliations

¹ Laboratory of Biomedical Nanotechnology, University of Vale do Paraiba, Av. Shishima Hifumi 2911, Sao Jose dos Campos 12224-000, São Paulo, Brazil.
² Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, State University of Sao Paulo (UNESP), Av. Engenheiro Francisco Jose Longo, 777, Sao Jose dos Campos 12245-000, SP, Brazil.
³ Laboratory of Biomedical Nanotechnology, University of Vale do Paraiba, Av. Shishima Hifumi 2911, Sao Jose dos Campos 12224-000, São Paulo, Brazil; Laboratory of Biomedical Nanotechnology, Biomedical Engineering Innovation Center, Universidade Brasil, Rua Carolina Fonseca 235, 08230-030, São Paulo, Brazil.
⁴ Chemistry Institute of Sao Carlos, University of Sao Paulo, Av. Trabalhador Sao-Carlense, 400, 13566-590 Sao Carlos, SP, Brazil.
⁵ Laboratory of Biomedical Nanotechnology, University of Vale do Paraiba, Av. Shishima Hifumi 2911, Sao Jose dos Campos 12224-000, São Paulo, Brazil; Laboratory of Biomedical Nanotechnology, Biomedical Engineering Innovation Center, Universidade Brasil, Rua Carolina Fonseca 235, 08230-030, São Paulo, Brazil; Department of Medicine, Biomaterials Innovation Research Center, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA 02139, USA; Department of Chemical Engineering, Northeastern University, Boston, MA 02115, USA.
⁶ Department of Chemical Engineering, Northeastern University, Boston, MA 02115, USA.
⁷ Laboratory of Biomedical Nanotechnology, University of Vale do Paraiba, Av. Shishima Hifumi 2911, Sao Jose dos Campos 12224-000, São Paulo, Brazil; Laboratory of Biomedical Nanotechnology, Biomedical Engineering Innovation Center, Universidade Brasil, Rua Carolina Fonseca 235, 08230-030, São Paulo, Brazil; Department of Medicine, Biomaterials Innovation Research Center, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA 02139, USA; Department of Chemical Engineering, Northeastern University, Boston, MA 02115, USA. Electronic address: aolobo@pq.cnpq.br.

PMID: 28183613
DOI: 10.1016/j.msec.2016.11.075

Abstract

Herein, we developed honeycomb-like scaffolds by combining poly (d, l-lactic acid) (PDLLA) with a high amount of graphene/multi-walled carbon nanotube oxides (MWCNTO-GO, 50% w/w). From pristine multi-walled carbon nanotubes (MWCNT) powders, we produced MWCNTO-GO via oxygen plasma etching (OPE), which promoted their exfoliation and oxidation. Initially, we evaluated PDLLA and PDLLA/MWCNTO-GO scaffolds for tensile strength tests, cell adhesion and cell viability (with osteoblast-like MG-63 cells), alkaline phosphatase (ALP, a marker of osteoblast differentiation) activity and mineralized nodule formation. In vivo tests were carried out using PDLLA and PDLLA/MWCNTO-GO scaffolds as fillers for critical defects in the tibia of rats. MWCNTO-GO loading was responsible for decreasing the tensile strength and elongation-at-break of PDLLA scaffolds, although the high mechanical performance observed (~600MPa) assures their application in bone tissue regeneration. In vitro results showed that the scaffolds were not cytotoxic and allowed for osteoblast-like cell interactions and the formation of mineralized matrix nodules. Furthermore, MG-63 cells grown on PDLLA/MWCNTO-GO significantly enhanced osteoblast ALP activity compared to controls (cells alone), while the PDLLA group showed similar ALP activity when compared to controls and PDLLA/MWCNTO-GO. Most impressively, in vivo tests suggested that compared to PDLLA scaffolds, PDLLA/MWCNTO-GO had a superior influence on bone cell activity, promoting greater new bone formation. In summary, the results of this study highlighted that this novel scaffold (MWCNTO-GO, 50% w/w) is a promising alternative for bone tissue regeneration and, thus, should be further studied.

Keywords: Alkaline phosphatase; Graphene oxide; In vivo evaluation; Multi-walled carbon nanotubes; Orthopedics; Poly (d, l-lactic acid).

MeSH terms

Animals
Biological Assay
Bone Regeneration / drug effects*
Bone and Bones / drug effects
Bone and Bones / pathology
Cell Line
Cell Survival / drug effects
Graphite / pharmacology*
Guided Tissue Regeneration*
Humans
Hydrophobic and Hydrophilic Interactions*
Male
Materials Testing
Nanotubes, Carbon / chemistry*
Nanotubes, Carbon / ultrastructure
Osteoblasts / cytology*
Osteoblasts / drug effects
Polyesters / chemistry
Polyesters / pharmacology*
Prosthesis Implantation
Rats
Stereoisomerism
Stress, Mechanical
Tensile Strength
Tissue Scaffolds / chemistry*

Substances

Nanotubes, Carbon
Polyesters
poly(lactide)
Graphite