Graphene-based 3D scaffolds in tissue engineering: fabrication, applications, and future scope in liver tissue engineering

Abstract

Tissue engineering embraces the potential of recreating and replacing defective body parts by advancements in the medical field. Being a biocompatible nanomaterial with outstanding physical, chemical, optical, and biological properties, graphene-based materials were successfully employed in creating the perfect scaffold for a range of organs, starting from the skin through to the brain. Investigations on 2D and 3D tissue culture scaffolds incorporated with graphene or its derivatives have revealed the capability of this carbon material in mimicking in vivo environment. The porous morphology, great surface area, selective permeability of gases, excellent mechanical strength, good thermal and electrical conductivity, good optical properties, and biodegradability enable graphene materials to be the best component for scaffold engineering. Along with the apt microenvironment, this material was found to be efficient in differentiating stem cells into specific cell types. Furthermore, the scope of graphene nanomaterials in liver tissue engineering as a promising biomaterial is also discussed. This review critically looks into the unlimited potential of graphene-based nanomaterials in future tissue engineering and regenerative therapy.

Keywords: 3D; graphene; liver; microenvironment; regenerative therapy; scaffold; stem cells; tissue engineering.

Figure 1

Schematic diagram of graphene 3D scaffolds in tissue engineering.

Figure 2

Schematic representation of the 2D and 3D scaffolds.

Figure 3

Structure of graphite, graphene, graphene oxide (GO), and reduced graphene oxide (RGO).

Figure 4

The effect of saturation temperature on the pore morphology and its distribution (in terms of diameter) of GO modified poly(propylene-carbonate) foams: (A) 20°C for 2 hrs, (B) 50°C for 2 hrs, and (C) 80°C for 2 hrs. Notes: Reprinted from Yang G, Su J, Gao J, Hu X, Geng C, Fu Q. Fabrication of well-controlled porous foams of graphene oxide modified poly (propylene-carbonate) using supercritical carbon dioxide and its potential 1820 tissue engineering applications. J Supercrit Fluids. 2013;73:1–9. Copyright 2013, with permission from Elsevier.

Figure 5

(A) SEM images of 3D GO hydrogels prepared with different ratios of cross-linking agent (G) with reducing agent (N) [(a) G/N-0/0, (b) G/N-0/1, (c) G/N-3/0, and (d) G/N-3/1)]. (B) Images of CS–HA–GO composite scaffold: (a) and (b) FESEM images showing the morphology, (c) photograph of CS–HA–GO composite scaffold. Notes: Figure A reprinted from Yu P, Bao R-Y, Shi X-J, Yang W, Yang M-B. Self-assembled high-strength hydroxyapatite/graphene oxide/chitosan composite hydrogel for bone tissue engineering. Carbohydr Polym. 2017;155:507–515. Copyright 2017, with permission from Elsevier. Figure B reprinted from Unnithan AR, Park CH, Kim CS. Nanoengineered bioactive 3D composite scaffold: a unique combination of graphene oxide andnanotopography for tissue engineering applications. Compos Part B Eng. 2016;90:503–511. Copyright 2016, with permission from Elsevier.

Figure 6

(A) SEM micrographs of electrospun nanofibers made of PLA and GO combinations: (a) PLA, (b) PLA/GO (1%), (c) PLA/GO (2%), (d) PLA/GO-g-PEG (1%), (e) PLA/GO-g-PEG (2%), and (f) PLA/GO-g-PEG (5%). (B) Images of electrospun scaffolds using TPU and GO combination (a) TPU, (b) 0.5% GO, (c) 1% GO, and (d) 2% GO. The presence of beading due to GO in the fibrous structure can be seen in the high magnification images of the composites. Notes: Figure A reprinted from Zhang C, Wang L, Zhai T, Wang X, Dan Y, Turng L-S. The surface grafting of graphene oxide with poly (ethylene glycol) as a reinforcement for poly (lactic acid) nanocomposite scaffolds for potential tissue engineering applications. J Mech Behav Biomed Mater. 2016;53:403–413. Copyright 2016, with permission from Elsevier. Figure B reprinted from Jing X, Mi H-Y, Salick MR, Cordie TM, Peng X-F, Turng L-S. Electrospinning thermoplastic polyurethane/graphene oxide scaffolds for small diameter vascular graft applications. Mater Sci Eng C. 2015;49:40–50. Copyright 2015, with permission from Elsevier.

Figure 7

Histological analysis for in vivo bone defect repair by different staining methods: (A) DAPI, (B) Goldner, (C) Masson’s trichrome staining, (D) Toluidine blue, (E) ALP, and (F) OCN. The size bar is 200 μm (all the images). (A color image can be viewed online). Notes: Reprinted from Nie W, Peng C, Zhou X, et al. Three-dimensional porous scaffold by self-assembly of reduced graphene oxide and nano-hydroxyapatite composites for bone tissue engineering. Carbon. 2017;116:325–337. Copyright 2017, with permission from Elsevier.

Figure 8

Healing images of rat tibial bone defects in vivo. (A) Representative X-ray photographs of bone defects of control clot (no filler), filled with GO/GN and filled with GO/CS/GN scaffolds after 2 weeks of implantation. (B) H&E staining and (C) Masson’s trichrome staining of rat tibial bone sections after 2 weeks of post-implantation. The scale bar is 100 μm. Notes: Reprinted from Saravanan S, Anjali C, Vairamani M, Sastry T, Subramanian K, Selvamurugan N. Scaffolds containing chitosan, gelatin and graphene oxide for bone tissue regeneration in vitro and in vivo. Int J Biol Macromol. 2017;104:1975–1985. Copyright 2017, with permission from Elsevier.

Figure 9

Evaluation of the wound healing effect of GF and GF + MSCs in the in vivo models. (A) Images of the different wound post-transplantation of 3, 7, 10, and 14 days. (B) Graph of wound area (%) in the experimental groups with the implantation time. Data were presented by means ± SEM. *p<0.05 and ^#p<0.01. Notes: Reprinted from Li Z, Wang H, Yang B, Sun Y, Huo R. Three-dimensional graphene foams loaded with bone marrow derived mesenchymal stem cells promote skin wound healing with reduced scarring. Mater Sci Eng C. 2015;57:181–188. Copyright 2015, with permission from Elsevier.

Figure 10

Histological examination images of the injury sites at 30 days post-injury by HvG staining. Spinal cords orientation indicated by the set of arrows: Ro – Rostral, C – Caudal, D – Dorsal, and V – Ventral. Notes: Reprinted from López-Dolado E, González-Mayorga A, Gutiérrez MC, Serrano MC. Immunomodulatory and angiogenic responses induced by graphene oxide scaffolds in chronic spinal hemisected rats. Biomaterials. 2016;99:72–81. Copyright 2016, with permission from Elsevier.