Polydimethylsiloxane (PDMS) is renowned for its versatility and unique properties, making it an ideal material for a wide range of applications. Its biocompatibility ensures safe interactions within biological environments, while its chemical inertness and thermal stability prevent reactions or degradation under physiological conditions. These attributes make PDMS an excellent choice for lubricating syringes and similar lab wares, where maintaining the integrity of stored fluids and biological samples is crucial. Although naturally hydrophobic, surface modification techniques can enhance its hydrophilicity, improving performance with aqueous solutions. These combined properties, along with its low cost and ease of fabrication, make PDMS invaluable in both research and industrial settings.
QSense sensors enable you to measure interaction with materials used in a wide range of areas. In the development of QSense PDMS sensors, we have harnessed the unique properties of this material. The PDMS sensors are designed to enable time-resolved surface interaction analysis at the nanoscale by QCM-D, providing insight into molecule-surface interactions and conformational changes. This capability offers valuable data for both research and industrial applications.
One area where the PDMS sensor is particularly useful is in the context of biopharmaceutical development, where it can be used to assess the stability and material compatibility of biopharmaceuticals. Here, we show a case example in the context of pre-filled syringes.
Pre-filled syringes are commonly used for the storage and administration of biopharmaceuticals. During these stages, the therapeutic drugs encounter various materials, such as glass syringe barrels, plastic caps, silicone oil for lubrication, and metal needles. Each surface interaction poses risks of adsorption, concentration loss, and formation of proteinaceous particles. Discovering these issues late in development can jeopardize timelines and incur significant financial costs. Screening for surface-induced instabilities during development can mitigate these risks.
QSense QCM-D analysis is a powerful tool for assessing antibody adsorption, providing insights into potential incompatibilities and mitigation strategies. For instance, pre-treatment steps like applying non-ionic surfactants can protect the PDMS layer from interacting with monoclonal antibodies (mAbs). Understanding the interactions between mAbs, non-ionic surfactants, and silicone oil at the oil/water interface is crucial. In this example, QSense QCM-D and the PDMS sensor, representing the silicone oil-coated syringe barrel, were used to analyze mAb adsorption.
The PDMS-coated sensor was first exposed to buffer to create a baseline. mAb was then introduced and after 2h of mAb exposure there was a rinse with buffer. The time resolved QCM-D raw data, Fig. 1, reveals the mAb-PDMS interaction dynamics and uptake. Upon surface exposure, the mAb adsorbs to the PDMS, and the adsorbed layer remains at the surface after rinse. The ΔD/Δf-ratio (data not shown) indicates that the mAb unfolds on this very hydrophobic surface when hydrophobic pockets on the protein bind to the sensor a scenario which has been suggested as the driving factor for particulate formation and aggregation in silicone oil coated pre-filled syringes [1]
Figure 1: QCM-D raw data, Δf and ΔD, showing the time resolved mAb - PDMS surface interaction.
QSense PDMS sensors leverage the inherent properties of PDMS to facilitate detailed, time-resolved QCM-D analysis of molecule-surface dynamics in various areas. The case study on mAb adsorption to silicone oil demonstrated how these sensors can be used in the biopharmaceutical field in the context of pre-filled syringes, by identifying and mitigating potential surface-induced instabilities in drug delivery systems.
Download the leaflet below to learn more about QSense PDMS sensors.
Mahrad is the Technical Product Manager for QSense Sensors at Biolin Scientific. He holds a Master of Science in Advanced Materials with a business approach from Aalto University and the Technical University of Darmstadt. Additionally, he has a Bachelor of Science in Metallurgical Engineering. Before joining Biolin Scientific, Mahrad spent several years in academia, focusing on the development of nanomaterials for mimicking extracellular vesicles as biosensors. He began his career at Biolin Scientific as a Product Specialist for the Attension product line before transitioning to his current role as the Technical Product Manager for the sensor team.
