Effect of doping in carbon nanotubes on the viability of biomimetic chitosan‐carbon nanotubes‐hydroxyapatite scaffolds

Abstract

This work describes the preparation and characterization of biomimetic chitosan/multiwall carbon nanotubes/nano-hydroxyapatite (CTS/MWCNT/nHAp) scaffolds and their viability for bone tissue engineering applications. The cryogenic process ice segregation-induced self-assembly (ISISA) was used to fabricate 3D biomimetic CTS scaffolds. Proper combination of cryogenics, freeze-drying, nature and molecular ratio of solutes give rise to 3D porous interconnected scaffolds with clusters of nHAp distributed along the scaffold surface. The effect of doping in CNT (e.g. with oxygen and nitrogen atoms) on cell viability was tested. Under the same processing conditions, pore size was in the range of 20-150 μm and irrespective on the type of CNT. Studies on cell viability with scaffolds were carried out using human cells from periosteum biopsy. Prior to cell seeding, the immunophenotype of mesenchymal periosteum or periosteum-derived stem cells (MSCs-PCs) was characterized by flow cytometric analysis using fluorescence-activated and characteristic cell surface markers for MSCs-PCs. The characterized MSCs-PCs maintained their periosteal potential in cell cultures until the 2nd passage from primary cell culture. Thus, the biomimetic CTS/MWCNT/nHAp scaffolds demonstrated good biocompatibility and cell viability in all cases such that it can be considered as promising biomaterials for bone tissue engineering.

One-dimensional nitrogen-containing carbon nanostructures

“…Biomimetic chitosan/MWNCNT/nano-hydroxyapatite scaffolds have been prepared by dispersing MWNCNTs in chitosan/nano-hydroxyapatite aqueous suspension at pH 6.0, followed by freeze-drying [513]. Ferritin and bovine serum albumin proteins were chemically bonded to MWNCNTs through a two-step process of diimide-activated amidation [514]: 1) carboxylated MWNCNTs were activated by N-ethyl-N′-(3-dimethylaminopropyl) carbodiimide hydrochloride, forming a stable active ester in the presence of N-hydroxysuccinimide; 2) the active ester was reacted with the amine groups on the proteins of ferritin or bovine serum albumin, forming an amide bond between the MWNCNTs and proteins.…”

Investigation of the dielectric, mechanical, and thermal properties of noncovalent functionalized MWCNTs/polyvinylidene fluoride (PVDF) composites

“…Stretching mode of C–O and C–N appear near 1000 cm –1 . These peaks imply the existence of functional groups attached to CS coated on the MWCNTs surface . Comparing Trition X‐100/MWCNTs to pristine MWCNTs, a new peak at 1511 cm −1 can be assigned to C–H bending on the long alkyl chain.…”

“…The characteristic carboxylate anion stretching band near 1400 cm −1 arises from the acetic acide exposure of the CS/MWCNTs . Stretching mode of C–O and C–N appear near 1000 cm –1 . These peaks imply the existence of functional groups attached to CS coated on the MWCNTs surface .…”

Stem Cells and Nanomaterials

“…Combination of MSCs with the latter nanomaterial is therefore very promising for cartilage regeneration, one of the most difficult tasks in regenerative medicine since this tissue is not vascularized. MWNTs could also be combined to chitosan or hydroxyapatite to successfully mimic bone tissue with acceptable pore size amenable to periosteal stem cell proliferation [130]. Single-walled carbon nanotubes (SWNTs) were also functionalized with poly lactic-co-glycolic acid to form a biocompatible substrate allowing proliferation and differentiation of pre-osteoblasts that successfully expressed mature osteoblast markers [131].…”