Torsional Deformation and COOH Concentration Effects on HIF-1α Release from N-MWCNTs

Abstract

Nitrogen-doped multi-walled carbon nanotubes with carboxyl groups (COOH-N-MWCNTs) are useful for targeted delivery of biomolecules. They have high chemical activity, and their surface can be modified by adding functional groups or by mechanical deformation. One important task is to control the release of proteins such as hypoxia-inducible factor 1-alpha (HIF-1α), which is important in cancer and cardiovascular diseases.
In this work, COOH-N-MWCNTs with oxygen concentrations in carboxyl groups of 2.7, 4.0, and 6.0 atomic percent were studied. Using the SCC DFTB method, atomic models of the nanotube surface were built. The HIF-1α protein was placed on these surfaces in different orientations. For each case, total energy, electronic density of states (DOS), activation energies, charge distribution, and other properties were calculated. Quantum equations of motion were also used to obtain a formula connecting the amount of released protein with its orientation, orbital interactions, and activation energy.
The results show that for 2.7% and 4.0% oxygen, the best surfaces for protein delivery have torsion angles from 0° to 15°, which allow slow and controlled release through a diffusion–wave mechanism. For 6.0% oxygen, twisting causes the nanotubes to break, so only flat (0° torsion) structures can be used. These findings help in designing CNT-based systems for controlled protein release.

The study was supported by the Russian Science Foundation grant No. 25-22-00377,
https://rscf.ru/project/25-22-00377/.

Speaker

Nadezda Bobenko
Institute of Strength Physics and Materials Science SB RAS
Россия

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