22.5.2025
Doctoral thesis on the fabrication of MSN-reinforced naturally derived hydrogels suitable for the delivery and immobilization of hydrophobic small-molecule drugs
M.Sc. (Pharmacy) Alaa Mahran’s doctoral thesis in Pharmaceutical Sciences will be put forth for public defence at the Faculty of Science and Engineering at Åbo Akademi University.
The thesis is entitled Mesoporous silica nanoparticles as a versatile drug delivery carrier for biologicals and small molecules.
The public defence of the doctoral thesis takes place on 28 May 2025, at 1PM in auditorium Argentum, Aurum, Henrikinkatu 2, Turku. You can also follow the doctoral defence online. Professor Timo Laaksonen, University of Helsinki, Finland, will serve as opponent and Professor Jessica Rosenholm, Åbo Akademi University, as custos.
Summary
Hydrogels are highly adaptable materials that can be precisely shaped using semi-solid extrusion 3D printing. However, they often require reinforcement to enhance their mechanical properties and functionality. A common strategy involves incorporating nanoparticles to form nanocomposite hydrogels, combining the benefits of both hydrogels and nanoparticles. Among the various nanoparticles, mesoporous silica nanoparticles (MSNs) offer exceptional potential in drug delivery due to their tunable particle and pore sizes, large surface area, and modifiable surface chemistry. These attributes facilitate the adsorption and immobilization of a broad range of therapeutic agents, including small molecules and biomacromolecules. This thesis aims to fabricate MSN-reinforced naturally derived hydrogels suitable for the delivery and immobilization of hydrophobic small-molecule drugs as well as biological proteins.
Additionally, the thesis investigates the interactions at three key interfaces within MSN-based nanocomposites and their influence on therapeutic outcomes: (1) between MSNs and the loaded cargo, (2) between MSNs and the hydrogel matrix, and (3) between MSNs and cells cultured within the matrix. Surface functionalization with neutral, positively, and negatively charged groups was employed to optimize loading capacity and assess the influence of net surface charge on protein activity, matrix compatibility, and intracellular delivery. It was found that different surface modifications played a pivotal role in controlling loading efficiency, release kinetics, and the biological activity of proteins. While oppositely charged surfaces exhibited high adsorption capacity, strong electrostatic interactions could compromise the biological activity of the loaded proteins.
Additionally, surface-modified MSNs enhanced the intracellular delivery of the hydrophobic drug compared to plain MSNs and improved therapeutic outcomes in applications such as tissue engineering and in vitro tumor modeling. This thesis provides a basis for a deeper understanding of nano–bio interfaces and their impact on the therapeutic performance of MSN-reinforced hydrogel systems, offering valuable insights into the design of advanced drug delivery platforms.
Alaa Mahran was born 1992 in Egypt. She can be reached by phone +358 45 166 7220 or email alaa.mahran@abo.fi.
The doctoral thesis can be read online through the Doria publication archive.
Click here for a press photo of the doctoral student.
Instructions for following the doctoral defence remotely:
To follow the defence, you need the Zoom software or the Google Chrome browser. You do not need to create a Zoom account to follow the defence. If you install the application, you participate by clicking on the meeting link, after which you should allow the link to open in the Zoom app.