# A Dialysis Membrane-Integrated Microfluidic Device for Controlled Drug Retention and Nutrient Supply

## TL;DR

A new microfluidic device with a dialysis membrane helps maintain realistic drug concentrations and nutrient supply for more accurate drug testing in the lab.

## Contribution

The novel integration of a dialysis membrane in a microfluidic device enables continuous drug retention and nutrient supply, mimicking in vivo pharmacokinetics.

## Key findings

- The dialysis membrane effectively retains high-molecular-weight drugs while allowing low-molecular-weight nutrients to pass through.
- Anticancer drug efficacy was successfully evaluated under continuously changing drug concentrations using the device.
- The device bridges the gap between static in vitro assays and physiological in vivo conditions for drug testing.

## Abstract

Traditional pre-clinical drug evaluation methods, including animal experiments and static cell cultures using human-derived cells, face critical limitations such as interspecies differences, ethical concerns, and poor physiological relevance. More recently, microphysiological systems (MPSs) that use microfluidic devices to mimic in vivo conditions have emerged as promising platforms. By enabling perfusion cell culture and incorporating human-derived cells, MPSs can evaluate drug efficacy and toxicity in a more human-relevant manner. However, standard MPS protocols rely on discrete medium changes, causing abrupt changes in drug concentrations that do not reflect the continuous pharmacokinetics seen in vivo. To overcome this limitation, we developed a Dialysis Membrane-integrated Microfluidic Device (DMiMD) which maintains continuous drug concentrations through selective medium change via a dialysis membrane. The membrane’s molecular weight cut-off (MWCO) enables the retention of high-molecular-weight drugs while facilitating the passage of essential low-molecular-weight nutrients such as glucose. We validated the membrane’s molecular selectivity and confirmed effective nutrient supply using cells. Additionally, anticancer drug efficacy was evaluated under continuously changing drug concentrations, demonstrating that the DMiMD successfully mimics in vivo drug exposure dynamics. These results indicate that the DMiMD offers a robust in vitro platform for accurate assessment of drug efficacy and toxicity, bridging the gap between conventional static assays and the physiological complexities of the human body.