Motility analysis of bacteria-based microrobot (bacteriobot) using chemical gradient microchamber

Area of Science:

• Biomedical Engineering
• Microfluidics
• Nanotechnology

Background:

• Bacteria-based microrobots (bacteriobots) offer potential for active drug delivery, leveraging tumor targeting, diagnosis, and therapy.
• Enhancing bacteriobot motility is crucial for effective therapeutic applications.

Purpose of the Study:

• To fabricate bacteriobots with enhanced motility via selective attachment of flagellar bacteria (Salmonella typhimurium).
• To quantitatively evaluate the chemotactic motility of these bacteriobots using a novel microfluidic chamber.

Main Methods:

• Selective bovine serum albumin (BSA) patterning on polystyrene (PS) microbeads for S. typhimurium attachment.
• Development of a microfluidic chamber to generate stable chemical gradients for chemotaxis evaluation.
• Quantitative assessment of S. typhimurium and bacteriobot directional movement in response to chemo-attractants (L-aspartic acid) and chemo-repellents (NiSO4).

Main Results:

• S. typhimurium showed a 16% increase in the chemo-attractant gradient and a 22% decrease in the chemo-repellent gradient.
• Bacteriobots exhibited similar chemotactic behavior, with a 14% increase in attractant and a 13% decrease in repellent gradients.
• The microfluidic system successfully demonstrated and quantified the directional motility of both bacteria and bacteriobots.

Conclusions:

• The fabricated bacteriobots display chemotactic motility comparable to S. typhimurium.
• The developed microfluidic chamber is an effective tool for quantitatively evaluating bacteriobot directional movement.
• These findings support the potential of bacteriobots as active drug delivery systems.