Biolin Scientific
User Days
November 18th–20th 2025

Quartz crystal microbalance with dissipation monitoring (QCM-D) is a powerful, surface-sensitive technique for probing dynamic biological and material phenomena at interfaces. QCM-D has long been valued in fundamental research and recent advances now point to expanding opportunities in translational science and industry-relevant applications. In this talk, I will begin with a brief overview of QCM-D measurement principles, followed by selected examples that illustrate how QCM-D is shaping current and future directions in biointerface science. Case studies will include applications in nanomedicine, antimicrobial detergents, biofouling, bioenergy, and biopharmaceutical development, drawing from academic and industry reports in the scientific literature. Particular emphasis will be placed on how QCM-D provides unique insights into outstanding scientific questions. I will also highlight recent examples from our laboratory, which demonstrate how QCM-D strategies can be integrated into broader experimental frameworks to support anticancer and anti-inflammatory drug discovery and development.   

Layer-by-layer assembly of polyelectrolyte multilayers (PEMs) offers a versatile platform for drug delivery and antimicrobial coatings. In this study, we developed PEM films using natural, oppositely charged polysaccharides. The aminoglycoside antibiotic gentamicin was incorporated as a model drug within specific bilayers during the assembly process. 

The film build-up and stability were systematically studied using Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) at a fixed pH, revealing well-defined multilayer growth and insights into viscoelastic properties. Atomic Force Microscopy (AFM) was employed to characterize the surface topography and the thickness of the multilayers, confirming uniform and nanoscale-structured film formation. 

Finally, the antibacterial activity of the gentamicin-loaded multilayers is currently under investigation against relevant bacterial strains to assess their potential for preventing microbial growth. These multilayer systems show promise for sustained drug delivery and surface-based antibacterial applications, particularly in biomedical and wound-healing contexts. 

Throughout the lifecycle of biopharmaceutical development and manufacturing, monoclonal antibodies (mAbs) are subjected to diverse interfacial stresses and encounter various container surfaces. These interactions can cause the formation of subvisible particles (SVPs) that complicate developability and stability assessments of the drug products. This study leverages quartz crystal microbalance with dissipation (QCM-D), an interfacial characterization technique, as well as both in silico and experimentally measured physicochemical properties, to investigate the significant differences in SVP formation among different mAbs due to interfacial stresses. We conducted forced degradation experiments in borosilicate glass and high-density polyethylene containers, using agitation and stirring to rank 15 mAbs on SVP risks. Our data indicate that the kinetics of antibody adsorption to solid–liquid interfaces correlate strongly with SVP propensity in the stirring study yet show a weaker correlation with agitation-induced SVPs. In addition, SVP morphology was analyzed using self-supervised machine learning on flow imaging microscopy images. Despite the differing surface chemistry of the two container types, stirring resulted in similar SVP morphologies, in contrast to the unique morphologies produced by agitation. Collectively, our research demonstrates the utility of QCM-D and in silico models in evaluating mAb developability and their tendency to form interface-mediated SVPs, providing a strategy to mitigate risks associated with SVP formation in biotherapeutic development. 

Authored by Anouk GALTAYRIE and Stéphanie DEVILLE-FOILLARD

Gold nanoparticles hold promise for biomedical applications such as imaging and therapy, but their use requires them to be functionalised to make them stable in solution and anti-adhesive to components of the biological environment. 

Good candidates for functionalisation include thiol-polyethylene glycol (HS-PEG). However, HS-PEG grafting is unstable in biological media, notably because of biological compounds (cysteine, glutathione) with thiol functions that compete to bind to the gold surface.  

In this work, laboratory synthetized polydentate polymers (cyclic and linear) with several anchoring functions (dithiolane, TA) and anti-adhesive functions (polysarcosine, pSar), both designed to improve (i) the anti-adhesive effect with respect to components in the biological environment and (ii) robustness with respect to thiol compounds have been used. 

By preparing our polymers in a 0.1% trifluoroacetic acid solution, we observed by QCM-D a non-reversible and repeatable adsorption of the polymers. The frequency variation values correspond to the quantities of a polymer monolayer adsorbed on the gold surface. XPS analyses enable us to track carbon, nitrogen, sulphur and gold. More specifically on the S 2p core level, we monitor the proportion of thiolate bonds (S-Au), which is high compared to the intermolecular disulphide bonds, observed if the polymers are prepared in pure water and responsible for an uncontrolled multilayer molecular structure on the surface. 

We also assessed the anti-adhesive effect of monolayers adsorbed in the presence of bovine serum albumin (BSA) by QCM-D. The results show that the cyclic polymer with 6 pSar14 chains and 4 TA functions has the best anti-adhesive properties. 

Finally, the robustness of the polymers deposited in monolayer was evaluated in competition experiments with dithiothreitol (DTT) followed by QCMD and XPS.