| dc.description.abstract | The 21st century dawned with remarkable advances in the controlled motion of nanoparticles. These particles could be manipulated through external energy sources (chemical, magnetic, acoustic, or biological), resulting in controlled navigation- earning the moniker “micro-nanomotors.” From a biological perspective, targeted navigation allows capabilities such as local rheological measurements, payload delivery (such as drugs and genetic material), and mechanical force application. Micro-nanomotors provide increased efficiency without increasing cost compared to conventional methodologies while allowing access to hard-to-reach locations and cavities in the body.
Helical magnetic nanomotors can be propelled by an externally applied rotating magnetic field- a scalable, non-invasive form of actuation with minimal effects on biological systems. Spatiotemporal manipulation and multifunctionality of these motors can be used for movement in blood, magnetic hyperthermia, active colloidal manipulation, manoeuvering inside living cells, and measurement of local viscosity. These properties of helical magnetic nanomotors make them ideal candidates for theranostics in medicine. We begin this work by developing a protocol for the large-scale manufacture of these nanomotors - a necessity for their biological applications.
The deciding factors for the clinical application of any formulation are toxicity and biodistribution. Despite the considerable research in micro-nanomotors, there is a lack of a comprehensive study on toxicity and biodistribution in cellular and animal models. Here, we address this issue by investigating the in-vitro and in-vivo toxicity and biodistribution of helical magnetic nanomotors. We use two different cell lines to evaluate the influence of nanomotors in cell death, cellular apoptosis, and gene expression. We also demonstrate the toxicity in-vivo in Balb/c mice and quantify the biodistribution of intravenously-injected nanomotors.
Radiotherapy is used in more than 50% of all cancer treatments. Despite recent technological advancements, radiotherapy suffers significant drawbacks such as normal tissue toxicity, radiation-induced out-of-field toxicity and obstacles such as tumour heterogeneity and cancer stem cells. Since the nanomotors were observed to be biocompatible, they were ideal candidates for therapeutics. In this work, we demonstrate the use of nanomotors as radiosensitizers through in-vitro studies in radioresistant MDA-MB-231 cells and in-vivo studies in Balb/c mice.
Engulfment of nanoparticles by phagocytic cells is another critical problem encountered in the field of nanomedicine. In this work, we present preliminary studies on using the manoeuvrability of nanomotors to escape phagocytosis by macrophages.
Many of the envisaged biological applications of nanomotors require the development of two crucial technologies. The first is to select and separate cells containing internalized nanomotors to scale up biophysical experiments. The second is to develop a live cell imaging system that is compatible with magnetic actuation. We conclude this work after describing our progress in addressing these two challenges. | en_US |
