PhD defense by Shahana Bishnoi

On Thursday 24 November 2022, Shahana Bishnoi will defend her PhD thesis " UV-assisted punching for fabrication of biocompatible microgel shapes for applications in drug delivery".


Time: 13.00

Place: Building101, Meeting Room 2 (R3.143) & zoom:

Please be aware that the PhD defense may be recorded - This will also be informed at the beginning of the PhD defense.


Supervisor: Associate Professor Leticia Hosta-Rigau

Co-Supervisor: Professor Stephan Sylvest Keller


Assessment committee:
Professor Niels B. Larsen, DTU Health Tech

Associate Professor Matthias Worgull, Karlsruhe Institute of Technology

Research Staff Member, Head of Advanced Nanofabrication Group Helmut Schift, Paul Scherrer Institute


Associate Professor Martin Dufva, DTU Health Tech


Hydrogels are 3D polymeric matrices that adsorb water while maintaining their structural integrity when placed in aqueous environments. They have become increasingly important for drug delivery of biomacromolecules due to their biocompatibility, porous matrix and high water content. Traditionally, hydrogel based micro- and nano-carriers have been fabricated by established bottom-up techniques, yielding spherical carriers. However, recent studies highlight that carrier shape and size play a significant role in carrier flow, bioadhesion, internalization and interaction with biological membranes. As a result, there has been high impetus in developing shape and size specific carriers for drug delivery, bringing top-down techniques to the forefront for their development.
In the current work, UV-assisted punching is introduced as a novel technique for the top-down fabrication of shape-specific hydrogel based carriers termed “microgel shapes” with varying geometries. It is a facile, temperature ambient and organic solventless method that allows for process integrated incorporation of biomacromolecules. Microgel shapes in circular, elliptical, square and rod-like geometries were successfully fabricated with carrier length varying from 100 – 8 μm and carrier height varying from 25 – 2 µm.  Biocompatibility of the developed microgel shapes was confirmed through hemocompatibilty and cell viability assays. The microgel shapes were successfully loaded with model biomacromolecules and in vitro release studies were performed to explore the potential of microgel shapes as carriers for their oral delivery. Finally, microgel shapes were loaded with an active enzyme to assess their potential as intravenous micro-reactors and retention of catalytic activity was confirmed through colorimetric assays.


Thu 24 Nov 22
13:00 - 16:00



Building 101, Meeting Room 2 (R3.143) & zoom