Novel Extrusion System for the Encapsulation of Drug Delivering Bio-Medical Micro-Robots

Presentation BY:

Malcolm T. Gibson

The University of ArizonaAdvanced Micro and Nano Systems Laboratory

Dept. of Aerospace and Mechanical Engineering

Presentation Objectives

• Introduction

• Micro-Robotics Research

• Encapsulation Methods

• The Extrusion System

• Drug Delivery Mechanisms

• Discoveries

• Conclusion

• Acknowledgements

Introduction - Bio-Medical Micro-Robots

• Bio-Medical Micro-Robots are wireless devices for the remote delivery of drugs to systems within the human body.

• Future Applications include:

– replacing high-risk

intraocular surgeries.

– Presenting an alternative to

invasive cancer treatments.

– Targeted Drug delivery

IRIS - ETH Zurich

Micro-Robot Research

Biomicrorobotics research is focused on building sub-mm sized, untethered robots for in-vivo medical applications.

Areas of Research:

- Structural Assembly

- Electroplating

- Drug Storage

- Encapsulation

- Bio-Polymers, Skin

- Remote Actuation

- Ultrasound

- Diffusion

- Magnetic Modulation

- Robot Propulsion

Building a complete robotic system that “swims” inside the human body is an advanced challenge and requires an innovative combination of Micro- and Nanotechnology.

IRIS - ETH ZurichIRIS - ETH Zurich

Micro-Robot Encapsulation

Encapsulation• Purpose

• Drug Storage • Drug Capacity

• Methods • Dip Coating • Soaking • Extrusion

• Materials • Sodium Alginate• Sunflower Oil

Co-fluidic robot extrusion system.

The extrusion system utilizes drop formation via a capillary tip in a multi-phase laminar flow regime. It is designed to uniformly encapsulate micro-robots within a drug complex.

Important Concepts

• Characterizing Flow Regimes• Co-Laminar Flow Mechanics• Reynold’s Numbers• Ohnesorge Numbers• Bond and Capillary Numbers• Interfacial Forces

Micro-Robot Drug Storage

Drug Storage - Methods and Materials

Soaks for 5 min.

Poly-l-lysine solution

Soaks for 4 min.

Polyethylenimine solution

NaAlg./ HRPDroplet

15 Min.

A

B

10 20 30 40 min.

CaCl2 solution

Drug Substitute - Horseradish Peroxidase - 44,000 Da enzyme protein

Drug Entrapment Matrix - Sodium Alginate - Cellulose fiber found in plant Cells - high strength and durability.

Surface Skin Formation - Polymer Coating - Inhibits release prior to actuation

Skin

Bare

Dru

g R

elea

sed

(n

g)

Micro-Robot Actuation

Actuation Mechanisms• Diffusion - Bare Robots

- Drug Limited by Area

• Magnetic Modulation

- Magnetic Interference

• Ultrasound

- Drug Encapsulation

Drug Release vs. Time

IRIS - ETH Zurich

Dru

g R

elea

sed

(n

g)

Time (min.)

Actuation

Discoveries and Conclusion

~ Thank you for your Attention ~~ Thank you for your Attention ~

The University of ArizonaAdvanced Micro and Nano Systems Laboratory

Dept. of Aerospace and Mechanical Engineering

Ultrasound has been confirmed as a successful alternative Release mechanism for encapsulated micro-robots while presenting new Capabilities for controlled drug release.

The utilization of a dual-phase extrusion system allows increased uniformity and controlled variability of the encapsulation process.

By Encapsulating micro-Robots we can increase in the drug capacity and storage capabilities of the Micro-robot.

Acknowledgement and Thanks

Acknowledgement and Thanks toDr. Eniko T. Enikov

Principal Investigator and Mentor

Advanced Micro and Nano-Systems laboratory GroupFor their help and guidance

UA/NASA Space Grant ProgramFor their support and research Encouragement

ASU/NASA Space Grant ProgramFor Organizing and Hosting the Statewide Symposium

The Institute of Robotics and Intelligent Systems (IRIS)ETH Zurich - Switzerland

The University of ArizonaAdvanced Micro and Nano Systems Laboratory

Dept. of Aerospace and Mechanical Engineering