PEOT/PBT ELECTROSPUN SCAFFOLDS TARGETING OSTEOPOROSIS

Not scheduled
20m
ICE Krakow

ICE Krakow

ul. Marii Konopnickiej 17 30-302 Kraków

Speaker

Tomasina, Clarissa (MERLN Institute for for Technology-Inspired Regenerative Medicine, Maastricht University )

Description

Introduction
Osteoporosis is a disease that interferes with bone homeostasis making the bone weak and susceptible to fractures. One of the areas affected is the pelvis, whose fractures force the patients to undergo invasive surgeries and long bed recovery.
Here, we aim at fabricating an electrospun composite scaffold based on PEOT/PBT and loaded with particles to promote bone regeneration as well as bioactive molecules to target osteoporosis. Mesoporous bioactive glasses (MBGs) and hydroxyapatite (nanoHA) particles were included due to their high bioactive character and ability to mimic bone morphological and chemical features. To hinder the osteoporotic process, ICOS-Fc, a molecule able to reversibly inhibit osteoclast activity, was grafted on the MBGs or directly on the PEOT/PBT scaffolds.

Methodology
Electrospun PEOT/PBT-based composite scaffolds were fabricated by dissolving 28% PEOT/PBT in chloroform:hexafluoroisopropanol (CHCl3:HFIP). MBGs and nanoHA particles were then incorporated at concentrations ranging from 5% to 15%. Composite scaffolds were characterized by means of scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and energy-dispersive X-ray spectroscopy (EDX).
Afterwards, MBGs were functionalized with ICOS-Fc (MBG_ICOS)1. MBG_ICOS were sonicated and afterwards incubated in CHCl3:HFIP. Supernatants were collected after sonication and incubation steps and particles were left to air dry for complete solvent removal. An ELISA-like assay was used to determine the presence and activity of ICOS-Fc in the supernatant and on the MBG_ICOS.
Alternatively, to graft ICOS-Fc directly onto the surface, scaffolds underwent aminolysis and then EDC/NHS chemistry. The efficiency of the grafting was evaluated through an ELISA-like assay and fluorescence using a fluorescent ICOS-Fc ligand (ICOS-L).
Finally, the effect of the ICOS-Fc on the scaffolds will be assessed by migration on U2OS, a human osteosarcoma cell line, positive for ICOSL.

Results
PEOT/PBT scaffolds were electrospun with MBGs and nanoHA at a percentage of up to 12,5% and 15%, respectively. Composite scaffolds showed a uniform distribution of particles into the meshes.
MBG_ICOS showed to be stable in the CHCl3:HFIP electrospinning solvent. In particular, the functionalized particles showed no decrease of presence and activity of ICOS-Fc before and after incubation in the solvent. Additionally, the supernatant collected after the sonication and incubation steps showed no ICOS-Fc present.
To graft ICOS-Fc on the meshes, aminolysis and EDC/NHS chemistry showed the possibility to bind around 25 ug/ml of ICOS-Fc to the scaffolds, which was measured through an ELISA-like assay. ICOS-L further confirmed the presence of the molecule on the fibers.
It is expected that the mobility of U2OS cells will be inhibited on the scaffolds, therefore evidencing the effect of ICOS-Fc on cell migration.

Conclusions
In conclusion, PEOT/PBT scaffolds were successfully spun alone and with MBGs and nanoHA particles. In addition, ICOS-Fc was incorporated into the meshes by functionalizing MBGs or by directly grafting on the electrospun fibers.
These results showed the potential to include in electrospun scaffolds not only particles such as nanoHA and MBGs, but also bioactive molecules able to target osteoporosis.

  1. Fiorilli, S., et al., Nanomaterials (Basel) (2021) 11 (2), 321

94238152929

Presentation materials

There are no materials yet.