@misc{10481/97654,
year = {2024},
month = {11},
url = {https://hdl.handle.net/10481/97654},
abstract = {Nanocrystalline apatite (Ap), known for its exceptional biological properties, faces limitations in hard tissue
engineering due to its poor mechanical properties. To overcome this limitation, we investigated the preparation
of nanocomposites through heterogeneous nucleation of calcium phosphate on exfoliated graphene (G) and
graphene oxide (GO) flakes, selected for their outstanding mechanical properties. The flakes were treated
(functionalized) with amino acids of varying isoelectric points—namely L-Arginine (Arg), L-Alanine (Aln) and LAspartic
acid (Asp)— as well as citrate (Cit) molecules. Furthermore, Tb3+ was incorporated into the formulations
to introduce luminescence and further enrich the functionality of the composite. The synthesis was conducted
using the sitting drop vapor diffusion method. Functionalized GO/Ap nanocomposites significantly
improved roughness, adhesion forces and elastic modulus compared to Ap and G-based particles. GO-Asp-Ap-Tb
nanocomposites exhibited the highest roughness (163.8 ± 116.2 nm), while G-Cit-Ap had the lowest (6.8 ± 5.6
nm). In terms of adhesion force, GO-Cit-Ap-Tb reached the highest value (31.06 ± 13.3 nN), while G-Arg-Ap had
the lowest (3.7 ± 1.8 nN) compared to Ap (13.6 ± 3.2 nN). For the elastic modulus, GO-Aln-Ap-Tb demonstrated
the greatest stiffness (3489 ± 101.01 MPa) compared to Ap (30.2 ± 6.5 MPa), while G-Aln-Ap-Tb showed the
lowest (17.2 ± 8.4 MPa). Concerning their luminescence, regardless of G/Ap and GO/Ap, the relative luminescence
intensities depended on the biomolecule used and decreased in the order Arg > Aln > Asp and Cit.
Furthermore, G/Ap and GO/Ap nanocomposites demonstrated good biocompatibility on murine mesenchymal
stem cells at low concentrations, showing cell viabilities exceeding 80 % at 0.1 μg/mL. This research offers a
novel approach to enhancing the mechanical properties of apatites while preserving their good biocompatibility
properties and introducing new functionalities (i.e. luminescence) in the composites, thereby expanding their
range of applications in hard tissue engineering.},
organization = {Spanish Agencia Estatal de Investigación of the Ministerio de Ciencia e Innovación y Universidades (MCIU),},
organization = {Bioscaffold project, ref. PGC2018-102047-B-I00 (MCIU/AEI/FEDER, UE)},
organization = {FPIgrant (Ref. PRE2019-088832) funded by the Spanish Agencia Estatal de Investigación of the MCIU},
publisher = {Elsevier},
keywords = {Graphene flakes},
keywords = {Graphene oxide},
keywords = {Nanocrystalline apatite},
title = {Biomolecule-functionalized exfoliated-graphene and graphene oxide as heteronucleants of nanocrystalline apatites to make hybrid nanocomposites with tailored mechanical, luminescent, and biological properties},
doi = {10.1016/j.ceramint.2024.10.034},
author = {Acebedo Martínez, Francisco Javier and Baldión, Paula Alejandra and Oltolina, Francesca and Follenzi, Antonia and Falini, Giuseppe and Fernández Sánchez, Jorge Fernando and Choquesillo Lazarte, Duane and Gómez- Morales, Jaime},
}