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.
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.
Laboratory of Biomedical Nanotechnology, University of Vale do Paraiba, Av. Shishima Hifumi 2911, Sao Jose dos Campos 12224-000, São Paulo, Brazil.
Edmundo
E
Silva
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.
Luana Marotta Reis de
LMR
Vasconcellos
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.
Bruno V M
BVM
Rodrigues
Chemistry Institute of Sao Carlos, University of Sao Paulo, Av. Trabalhador Sao-Carlense, 400, 13566-590 Sao Carlos, SP, Brazil.
Danilo Martins
DM
Dos Santos
Chemistry Institute of Sao Carlos, University of Sao Paulo, Av. Trabalhador Sao-Carlense, 400, 13566-590 Sao Carlos, SP, Brazil.
Sergio P
SP
Campana-Filho
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.
Fernanda Roberta
FR
Marciano
Department of Chemical Engineering, Northeastern University, Boston, MA 02115, USA.
Thomas J
TJ
Webster
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.
Anderson Oliveira
AO
Lobo
D000818:Animals; D001681:Biological Assay; D001861:Bone Regeneration / Q000187:drug effects*; D001842:Bone and Bones / Q000187:drug effects / Q000473:pathology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D006108:Graphite / Q000494:pharmacology*; D048091:Guided Tissue Regeneration; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008297:Male; D008422:Materials Testing; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects; D011091:Polyesters / Q000737:chemistry / Q000494:pharmacology*; D019919:Prosthesis Implantation; D051381:Rats; D013237:Stereoisomerism; D013314:Stress, Mechanical; D013718:Tensile Strength; D054457:Tissue Scaffolds / Q000737:chemistry*
D037742:Nanotubes, Carbon; D011091:Polyesters; C033616:poly(lactide); D006108:Graphite
Alkaline phosphatase; Graphene oxide; In vivo evaluation; Multi-walled carbon nanotubes; Orthopedics; Poly (d, l-lactic acid)