Scaffolds with Magnetic Nanoparticles for Tissue Stimulation

Abstract

Magnetic nanoparticles (MNPs) have been used in several medical applications, including targeted hyperthermia, resonance tomography, diagnostic sensors, and localized drug delivery. Further applications of magnetic field manipulation through MNPs in tissue engineering have been described. The current study aims to develop tissue-engineered polymeric scaffolds with incorporated MNPs for applications that require stimulation of the tissues such as nerves, muscles, or heart. Electrospun scaffolds were obtained using 14%w/v polycaprolactone (PCL) in 2,2,2-Trifluoroethanol (TFE) at concentrations of 5% & 7.5%w/v of dispersed MNPs (iron oxide, Fe3O4, or cobalt iron oxide, CoFe2O4). Scaffolds were analyzed using scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy, uniaxial tensile testing, and cell seeding for biocompatibility. Human bone marrow mesenchymal stem cells (bmMSCs) were seeded on the scaffolds. Biocompatibility was assessed by metabolic activity with Resazurin reduction assay on day 1, 3, 7, 10. Cell-cell and cell-scaffold interactions were analyzed by SEM. Electrospun scaffolds containing MNPs showed a decrease in fiber diameter as compared to scaffolds of pure PCL. The maximum force increases with the inclusion of MNPs, with higher values revealed for iron oxide. The metabolic activity decreased with MNPs, especially for cobalt iron oxide at a higher concentration. On the other hand, the cells developed good cell-scaffold and cell-cell interactions, making the proposed scaffolds good prospects for potential use in tissue stimulation.

Antibacterial and osteoinductive properties of wollastonite scaffolds impregnated with propolis produced by additive manufacturing

“…Cell viability measurements were taken at 1, 3, 7, 14, 21, and 28 days. Cell viability was determined using a resazurin reduction method [ 45 ]. A working solution of 44 μM Alamar Blue Reagent was prepared in a preheated culture medium immediately before the experiments, and 1 ml was added to the samples.…”

Magnetic Force Microscopy and Nanoindentation on 3D Printed Magnetic Scaffolds for Neuronal Cell Growth

“…68 Electrospun PCL fibers containing MNPs (0, 5, or 7 wt/v%) were analyzed using uniaxial tensile testing for samples swollen in PBS at 37 °C; the magnetic PCL samples were stiffer than pure PCL fibers due to the alignment of the MNPs. 73 Copper and silver particles filled PLA nanocomposites prepared via fused filament fabrication (FFF) additive manufacturing; the incorporation of bronze particles into the neat PLA increases the elastic modulus up to 10 and 27% for samples printed in 0 and 90°configurations, respectively, whereas the stiffness increased up to 103% for silver-filled PLA nanocomposite scaffolds. 74 3D printed hybrid magnetorheological silicon-based elastomers were softer than the pure elastomer when no external magnetic field was applied, but under a magnetic field, they presented higher stiffness compared to that of the pure elastomer.…”

“…For instance, magnetic poly­(ε-caprolactone) (PCL) samples were cast and freeze-dried; the Young’s modulus ( E ) values determined by dynamic mechanical analysis for wet PCL scaffolds increased from 1.2 to 1.4 and 2.4 MPa; 5 and 10 wt % of MNPs were added . Electrospun PCL fibers containing MNPs (0, 5, or 7 wt/v%) were analyzed using uniaxial tensile testing for samples swollen in PBS at 37 °C; the magnetic PCL samples were stiffer than pure PCL fibers due to the alignment of the MNPs . Copper and silver particles filled PLA nanocomposites prepared via fused filament fabrication (FFF) additive manufacturing; the incorporation of bronze particles into the neat PLA increases the elastic modulus up to 10 and 27% for samples printed in 0 and 90° configurations, respectively, whereas the stiffness increased up to 103% for silver-filled PLA nanocomposite scaffolds .…”

In vitro evaluation of the osteogenic and antimicrobial potential of porous wollastonite scaffolds impregnated with ethanolic extracts of propolis

“…The scaffolds were cultured in 24-well plates (TPP, Switzerland) in growth medium supplemented with Dulbecco’s modified Eagle medium (Bio&Sell, Germany) containing 2.3% (v/v) stable glutamine, 2.3% (v/v) HEPES, 0.002% (v/v) FGF-2, 11.6% (v/v) fetal bovine serum (Bio&Sell, Germany), and 1.2% (v/v) penicillin/streptomycin. The medium was replaced every 2 days during the first 7 days of culture ( Leal-Marin et al, 2021 ). Subsequently, the cells were cultivated to a differentiation medium by adding 5 mM β-glycerophosphate (Merck, Germany), 50 mM ascorbic acid (Merck, Germany), and 10 nM dexamethasone (Merck, Germany) for 28 days ( Pelaez-Vargas et al, 2012 ).…”

“…Cell proliferation was evaluated at day (1, 3, 7, 14, 21 and 28) using Alamar Blue assay. Cultures were incubated for 1.5 h and fluorescence was quantified using a multiplate reader (Tecan Infinite M200 Nanoquant, United States) at 570 nm (excitation wavelength) and 600 nm (emission wavelength) ( Leal-Marin et al, 2021 ). The results were expressed as the percentage of viability found in the scaffolds relative to the control samples sown in the wells without scaffolds.…”