TY  - GEN
AV  - public
TI  - Biocompatible active microcarriers
KW  - degradable
microparticle
nanoparticle
active
motion
magnetics
propulsion
biocompatible
carrier
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/36515/
CY  - Heidelberg
Y1  - 2025///
A1  - Peter, Florian Ralf
N2  - Modern medicine is on the verge of evolving from traditional methods based on the systemic administration of chemical drugs, radiation therapies, and invasive surgeries towards a new era of more sophisticated, targeted approaches. The emergence of new technologies and deeper comprehension of biological mechanisms allowed scientists to engineer more targeted treatment options that better address the  fundamental causes of diseases. The potential of active micro- and nanomachines lies in their ability to perform tasks or deliver therapeutics at the same length scale as biological machinery. However, very few new treatment options have been approved and integrated into standard medical practices. A significant concern is that synthetic nano- and microstructures do not meet the necessary biosafety standards, primarily due to their frequent reliance on inorganic, toxic materials. A lack of long-term toxicology studies is even preventing the implementation of biocompatible designs, because there are no effective retrieval strategies available.
The first part of this thesis investigates how biological building blocks can be re-imagined to function outside of their typical purpose and environment, thereby attaining novel functionalities. DNA nanotechnology was employed to program unreactive DNA strands to self-assemble into a larger structure. The combination of a DNA scaffold with catalytically active platinum nanoparticles has enabled the successful fabrication of a unique active hybrid nanostructure. This combination of such fundamentally different materials was demonstrated to be stable and active in a high-energy fuel, which presents a multitude of potential applications, including the fabrication of chemical motors and larger functional machinery.
In the context of biological applications, the use of magnetic helical microswimmers for the transportation of medicines over longer distances within biological environments is regarded as the most promising approach. By replacing the conventional materials typically used to construct such structures, the author has fabricated an almost entirely biodegradable variant composed of magnesium and zinc. This directly addresses the biosafety concerns associated with the use of microcarriers in biomedical applications, thereby circumventing the need for a retrieval strategy. The demonstrated transport capabilities and adjustable degradation behaviour provide an actively guided transportation platform that can release therapeutics over time. The presented research represents a notable advancement over existing active microswimmers, particularly in the context of targeted drug or gene delivery.
The eye and its associated diseases were investigated as a potential target organ for the implementation of such active, degradable microcarriers. The current limitations of retinal therapy were surveyed and addressed using active microswimmers to identify solutions that are not available with conventional methods. The degradation of biological barriers with enzymes or the condensation of DNA into extremely small nanoparticles were demonstrated as promising research directions, both of which can potentially be combined with and benefit from targeted delivery through active microswimmers. The work shown in this thesis therefor helps bridge the technological gap between the envisioned applications for active microcarriers and the state of the art.
ID  - heidok36515
ER  -