Swimming microorganisms acting as nanorobots versus artificial nanorobotic agents: A perspective view from an historical retrospective on the future of medical nanorobotics in the largest known three-dimensional biomicrofluidic networks

Abstract

The vascular system in each human can be described as a 3D biomicrofluidic network providing a pathway close to approximately 100 000 km in length. Such network can be exploited to target any parts inside the human body with further accessibility through physiological spaces such as the interstitial microenvironments. This fact has triggered research initiatives towards the development of new medical tools in the form of microscopic robotic agents designed for surgical, therapeutic, imaging, or diagnostic applications. To push the technology further towards medical applications, nanotechnology including nanomedicine has been integrated with principles of robotics. This new field of research is known as medical nanorobotics. It has been particularly creative in recent years to make what was and often still considered science-fiction to offer concrete implementations with the potential to enhance significantly many actual medical practices. In such a global effort, two main strategic trends have emerged where artificial and synthetic implementations presently compete with swimming microorganisms being harnessed to act as medical nanorobotic agents. Recognizing the potentials of each approach, efforts to combine both towards the implementation of hybrid nanorobotic agents where functionalities are implemented using both artificial/synthetic and microorganism-based entities have also been initiated. Here, through the main eras of progressive developments in this field, the evolutionary path being described from some of the main historical achievements to recent technological innovations is extrapolated in an attempt to provide a perspective view on the future of medical nanorobotics capable of targeting any parts of the human body accessible through the vascular network.

Unlocking the Potential of Magnetotactic Bacteria as Magnetic Hyperthermia Agents

“…In the last years, a few groups have started to investigate the possibility of using magnetotactic bacteria as nanobiots for cancer treatment. [23,24,27,28] These groups have focused mainly on tracking and analyzing the movement of bacteria in different environments, [29] studying the potential penetration of bacteria into tumors, [30] developing novel magnetic systems to remotely control and guide these bacteria, [31] analyzing their biocompatibility and navigation in blood stream, [32] etc. The initial results have been very positive and there have already been in vivo tests demonstrating the efficiency of these bacteria in tumors targeting.…”

Nanotechnology and stem cells in vascular biology

“…the classification into drug agent or medical device by the principle of action). A safe definition is an artificial device composed of nanoscale components and up to 10 µm in size (5). This description is not standard and that might explain the various and sometimes misused denomination of nanorobots to bionanotechnological devices.…”

“…Another application of nanorobots is the individualization and targeting of microvasculature not accessible with conventional techniques (5). Notable examples include the cerebral vasculature and the network of small tumoral masses that escape resection or conventional therapies.…”

The Fantastic Voyage of the Trypanosome: A Protean Micromachine Perfected during 500 Million Years of Engineering

“…The aim is for the devices to act at the nanoscale, i.e., on the molecular level. Accordingly, medical micro- or nanobots would be micromachines powered by nanoscale motor mechanisms and perform in the delivery of molecules or manipulations of molecular and cellular structures in specific regions of the body [ 2 , 3 , 4 , 5 , 6 ]. The first major challenges for realisation of this concept lie in the creation of mechanisms for propulsion and navigation of the machines in the bloodstream and in tissues, i.e., the engineering of controllable microswimmers [ 7 , 8 , 9 , 10 ].…”