Biomimetic three-dimensional nanocrystalline hydroxyapatite and magnetically synthesized single-walled carbon nanotube chitosan nanocomposite for bone regeneration

Abstract

Background: Many shortcomings exist in the traditional methods of treating bone defects, such as donor tissue shortages for autografts and disease transmission for allografts. The objective of this study was to design a novel three-dimensional nanostructured bone substitute based on magnetically synthesized single-walled carbon nanotubes (SWCNT), biomimetic hydrothermally treated nanocrystalline hydroxyapatite, and a biocompatible hydrogel (chitosan). Both nanocrystalline hydroxyapatite and SWCNT have a biomimetic nanostructure, excellent osteoconductivity, and high potential to improve the load-bearing capacity of hydrogels. Methods: Specifically, three-dimensional porous chitosan scaffolds with different concentrations of nanocrystalline hydroxyapatite and SWCNT were created to support the growth of human osteoblasts (bone-forming cells) using a lyophilization procedure. Two types of SWCNT were synthesized in an arc discharge with a magnetic field (B-SWCNT) and without a magnetic field (N-SWCNT) for improving bone regeneration. Results: Nanocomposites containing magnetically synthesized B-SWCNT had superior cytocompatibility properties when compared with nonmagnetically synthesized N-SWCNT. B-SWCNT have much smaller diameters and are twice as long as their nonmagnetically prepared counterparts, indicating that the dimensions of carbon nanotubes can have a substantial effect on osteoblast attachment. Conclusion: This study demonstrated that a chitosan nanocomposite with both B-SWCNT and 20% nanocrystalline hydroxyapatite could achieve a higher osteoblast density when compared with the other experimental groups, thus making this nanocomposite promising for further exploration for bone regeneration.

Nanoengineered biomimetic hydrogels for guiding human stem cell osteogenesis in three dimensional microenvironments

“…For example, in a recent work, nanocrystalline hydroxyapatite and single-walled carbon nanotubes were used in combination with hydrogel to impart improved bioactivity and mechanical properties to the nanocomposite hydrogels for bone tissue engineering. 14 In another approach, Henstock et al , remotely activated human mesenchymal stem cells (hMSCs) through mechanotransduction in collagen hydrogel using MNPs to provide necessary stimulations for bone regeneration. 15 Other nanomaterials recently used to prepare nanocomposite hydrogels for such orthopedic applications include bioprinted ceramic nanoparticles, gold nanoparticles, electrospun organic–inorganic nanofibers, and bioceramics.…”

Design of a Novel 3D Printed Bioactive Nanocomposite Scaffold for Improved Osteochondral Regeneration

“…Similar to our previous studies, morphological analysis of synthesized nHA displayed grain sizes in the range of 50–100 nm in length and 20–30 nm in width. 26 More importantly, with the incorporation of 60 wt% nHA in the subchondral region, a 61% increase in compressive modulus and 87% increase in ultimate compressive strength were observed.…”

“…After 20 h, the nHA precipitate was centrifuged and rinsed thoroughly with water three times, dried at 80 °C for 12 h and ground into a fine powder and thoroughly characterized as described in our previous work. 26-31 …”

Integrating biologically inspired nanomaterials and table-top stereolithography for 3D printed biomimetic osteochondral scaffolds

“…A wet chemistry plus hydrothermal treatment method was used to synthesize nHA with good crystallinity and nanometer particle size as described in our previous papers 32–36 . Briefly, 37.5 mL of a 0.6 M ammonium phosphate (Sigma Aldrich, St. Louis, MO) solution was added to 375 mL of water and adjusted to pH 10 with ammonium hydroxide (Fisher Scientific, Pittsburgh, PA).…”