Skip to content

Integrated Remotely Reconfigurable Capsule Pump for Drug Delivery Systems

A shape memory alloy actuated micro-pump optimized for drug delivery applications

Published: 31st August 2021
Integrated Remotely Reconfigurable Capsule Pump for Drug Delivery Systems
Source: lukszczepanski, https://stock.adobe.com/uk/275432620, stock.adobe.com

Background

Wound healing is a complex process that involves several overlapping and subtle stages; therefore, effective treatment of chronic wounds requires real-time monitoring of the wound healing biomarkers (e.g., pH and temperature). There are several types of ‘smart-bandage’ under development particularly aimed towards chronic and non-healing wounds and include functions such as:

• Monitoring the healing progress;

• Removing excessive constituents such as excess moisture or compounds (e.g., elastase) which hinders healing;

• Detecting bacterial infection and;

• Delivering drugs or growth factors as required to promote faster healing.

However, the majority of these strategies rely on the topical and passive delivery of therapeutics, which are shown to have low success rates and ineffectiveness because of the following (i) failure to address the existence of necrotic tissue and thick crust typically covering chronic wounds (where the live tissue is located below them), (ii) the lack of vascularization in wound surface, (iii) aggressive and inefficient response of the immune system due to the hypoxic wound environment. 

Moreover, none of these strategies incorporate drug delivery, oxygenation, and vacuum therapy in one integrated platform. Accordingly, utilizing new drug delivery tools can facilitate and optimize transdermal delivery of therapeutics and provide new treatment methods in chronic wound care. 

Technology Overview

The proposed novel design integrates a built-in drug reservoir within the pump package forming a self-contained preloaded capsule pump. The new design results in a compact, simple, and inexpensive micro‑pump and reduces the probability of contamination with attained almost zero dead volume values, which is lower than the state-of-the-art micro‑pumps. The pump consists of a NiTi-alloy SMA spring embedded in a flexible polymeric capsule and actuated by joule heating. Unlike other SMA micro‑pump designs actuate by diaphragm strips or wires, our design can achieve strokes in the order of 6 mm at a 27% deflection ratio, and output pressures up to 14 kPa were successfully attained resulting in flow rates exceeding 2524 µl/min under free convention conditions. Pump frequency up to 4 Hz was successfully achieved. The pump was optimized for maximum stroke and pressure in a closed-loop manner. The stroke and the pump’s output pressure are controlled by changing the applied voltage, whereas the frequency of the pump is controlled by the input signal. Two bicuspid polymeric check-valves are designed and integrated onto the pump to control the flow direction. The reservoir is replaceable which makes the pump capsule reusable after pumping all the vaccine inside it. This pump will be reconfigured wirelessly by the doctor to pump the vaccine into the patient. To ensure that the released drug amount matches the desired dosage and never exceeds the safety limits, a dose tracker is added to the pump. A custom-made micro thermo-anemometer is placed at the output of the pump. This allows for closed-loop feedback control over the pump and ensures that no drug is released when undesired.

Benefits

(1) Miniaturized to a total size of fewer than 500 mm3 by utilizing SLA 3D printing technology.

(2) Incorporation of a feedback tracking sensor to send real-time information to confirm the delivered dose and pump status. 

(3) Online remote dose reconfigurability.

Applications

Implantable and wearable drug delivery systems used for diabetes control, cancer treatment, chronic wound healing, and chronic pain management.

Opportunity

  • Development partner
  • Commercial partner
  • Licensing
  • University spin out
  • Seeking investment
Patents
  • US Provisional Patent Application - filed on 30/03/2021
  • 63/167783
IP Status
  • Patent application submitted
  • Provisional patent
Seeking
  • Seeking investment
  • University spin out
  • Licensing
  • Commercial partner
  • Development partner