Three‐dimensional carbon nanotube scaffolds for long‐term maintenance and expansion of human mesenchymal stem cells

Abstract

Expansion of mesenchymal stem cells (MSCs) and maintenance of their self-renewal capacity in vitro requires specialized robust cell culture systems. Conventional approaches using animal-derived or artificial matrices and a cocktail of growth factors have limitations such as consistency, scalability, pathogenicity, and loss of MSC phenotype. Herein, we report the use of all-carbon 3-D single- and multiwalled carbon nanotube scaffolds (SWCNTs and MWCNTs) as artificial matrices for long-term maintenance and expansion of human MSCs. Three-dimensional SWCNT and MWCNT scaffolds were fabricated using a novel radical initiated thermal cross-linking method that covalently cross-links CNTs to form 3-D macroporous all-carbon architectures. Adipose-derived human MSCs showed good cell viability, attachment, proliferation, and infiltration in MWCNT and SWCNT scaffolds comparable to poly(lactic-co-glycolic) acid (PLGA) scaffolds (baseline control). ADSCs retained stem cell phenotype after 30 days and satisfied the International Society for Cellular Therapy's (ISCT) minimal criteria for MSCs. Post expansion, (1) ADSCs showed in vitro adherence to tissue culture polystyrene (TCPS); (2) MSC surface antigen expression [CD14(-), CD19(-), CD34(-), CD45(-), CD73(+), CD90(+), CD105(+)]; and (3) trilineage differentiation into osteoblasts, adipocytes, and chondrocytes. Results show that cross-linked 3-D MWCNTs and SWCNTs scaffolds are suitable for ex vivo expansion and maintenance of MSCs for therapeutic applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1927-1939, 2017.

Enhanced osteogenic differentiation of mesenchymal stem cells in ankylosing spondylitis: a study based on a three-dimensional biomimetic environment

“…Our previous study demonstrated for the first time that AS-MSCs outperform HD-MSCs in osteogenic differentiation when cultured in a 2D system in vitro 12 . However, some studies reported that the function of cells in 2D culture cannot completely reflect their real capacity in vivo 24 . Recently, 3D biomimetic microenvironments with different types of materials have been widely used in cellular function studies 25 .…”

The Advances in Biomedical Applications of Carbon Nanotubes

“…In this regard, researchers have been working on the fabrication and optimization of CNT-based nano-constructs to serve as a scaffold for mesenchymal stem cells. For example, Lalwani et al fabricated all-carbon 3-D singleand multiwalled CNT scaffolds as artificial matrices for long-term maintenance and expansion of human adipose-derived human mesenchymal stem cells [154]. The fabricated scaffolds demonstrated a good level of cell viability, attachment, proliferation, and infiltration in CNT scaffolds comparable to poly(lactic-co-glycolic) acid (PLGA) scaffolds.…”

Two‐dimensional graphene oxide‐reinforced porous biodegradable polymeric nanocomposites for bone tissue engineering

“…Furthermore, cells were metabolically active and the formation of filopodia and cellular extensions (Figure d, white arrows) extending outward from the cell body (black circles) was observed. It is critical for cells to attach and infiltrate the porous scaffolds and initiate the deposition of ECM proteins for effective new tissue regeneration . Collagen‐I protein acts as a binder to facilitate the attachment of cells with scaffolds and other ECM components thereby playing an essential role in cellular signaling, differentiation and tissue maturation .…”

“…It is critical for cells to attach and infiltrate the porous scaffolds and initiate the deposition of ECM proteins for effective new tissue regeneration. [43][44][45]53 Collagen-I protein acts as a binder to facilitate the attachment of cells with scaffolds and other ECM components thereby playing an essential role in cellular signaling, differentiation and tissue maturation. 54 Immunofluorescence imaging confirms that cells are able to express and secrete collagen-I protein.…”

“…Protein adsorption on scaffolds is essential for cellular adhesion and ECM deposition. [43][44][45] Here, we have assessed the adsorption of collagen-I protein (Figure 4) using a wellaccepted protein solution depletion method 24 employing bicinchoninic acid assay. 46 Collagen-I is the principal constituent of the ECM.…”