Quantifying and modeling loss of estrogen and progesterone in PDMS-based devices

Area of Science:

• Biomaterials Science
• Chemical Engineering
• Endocrinology

Background:

• Polydimethylsiloxane (PDMS) is widely used in microfluidic cell culture.
• Previous studies suggested PDMS sequesters hormones, but specific interaction parameters were unknown.
• This limits the assessment of PDMS-based devices for hormone studies.

Purpose of the Study:

• To quantify the interaction parameters between PDMS and specific steroid hormones.
• To evaluate the impact of these interactions on dynamic hormone dosing protocols in microfluidic devices.
• To provide critical data for designing reliable PDMS-based microfluidic systems for hormone research.

Main Methods:

• Quantification of chemical-PDMS interactions for estradiol, aldosterone, and progesterone.
• Computational modeling of dynamic dosing protocols (pulsed/bolus delivery, circadian control).
• Analysis of flow-rate dependency and static conditions on hormone-PDMS interactions.

Main Results:

• Aldosterone showed no detectable interaction with PDMS.
• Estradiol exhibited modest interaction, while progesterone showed strong interaction.
• PDMS interactions significantly disrupted dynamic dosing protocols in a chemical-specific and flow-rate-dependent manner.
• Estradiol-PDMS interactions were notable at low flow rates but negligible at high flow rates.

Conclusions:

• The binding affinity of hormones to PDMS varies significantly (progesterone > estradiol > aldosterone).
• PDMS-material interactions critically affect the accuracy of dynamic hormone delivery in microfluidic devices.
• These findings are essential for optimizing the design and application of PDMS microfluidic systems for precise steroid hormone research.