Supported Lipid Bilayer Platform for Characterizing the Membrane-Disruptive Behaviors of Triton X-100 and Potential Detergent Replacements

Abstract

Triton X-100 (TX-100) is a widely used detergent to prevent viral contamination of manufactured biologicals and biopharmaceuticals, and acts by disrupting membrane-enveloped virus particles. However, environmental concerns about ecotoxic byproducts are leading to TX-100 phase out and there is an outstanding need to identify functionally equivalent detergents that can potentially replace TX-100. To date, a few detergent candidates have been identified based on viral inactivation studies, while direct mechanistic comparison of TX-100 and potential replacements from a biophysical interaction perspective is warranted. Herein, we employed a supported lipid bilayer (SLB) platform to comparatively evaluate the membrane-disruptive properties of TX-100 and a potential replacement, Simulsol SL 11W (SL-11W), and identified key mechanistic differences in terms of how the two detergents interact with phospholipid membranes. Quartz crystal microbalance-dissipation (QCM-D) measurements revealed that TX-100 was more potent and induced rapid, irreversible, and complete membrane solubilization, whereas SL-11W caused more gradual, reversible membrane budding and did not induce extensive membrane solubilization. The results further demonstrated that TX-100 and SL-11W both exhibit concentration-dependent interaction behaviors and were only active at or above their respective critical micelle concentration (CMC) values. Collectively, our findings demonstrate that TX-100 and SL-11W have distinct membrane-disruptive effects in terms of potency, mechanism of action, and interaction kinetics, and the SLB platform approach can support the development of biophysical assays to efficiently test potential TX-100 replacements.

Unraveling the Biophysical Mechanisms of How Antiviral Detergents Disrupt Supported Lipid Membranes: Toward Replacing Triton X-100

“…At low probe concentrations in PBS, the fluorescence emission peak wavelength is ∼477 nm. , As micelles form at the detergent CMC, the probe molecules partition into the hydrophobic center of the micelles and the emission peak blue-shifts due to the change in local dielectric properties. The CMC values in PBS were determined to be around 400 μM for TXR, 8 μM for PS80, 60 μM for PS20, and 20 μM for BC10, while the previously determined CMC value for TX-100 is ∼300 μM . The experimentally measured CMC values agree well with past reports. ,,− …”

“…The CMC values in PBS were determined to be around 400 μM for TXR, 8 μM for PS80, 60 μM for PS20, and 20 μM for BC10, while the previously determined CMC value for TX-100 is ∼300 μM. 27 The experimentally measured CMC values agree well with past reports. 27,29,36−39 Detergent CMC values mainly depend on amphiphile hydrophobicity, with greater hydrophobicity typically equaling lower CMC values.…”

“…Figure 4 presents the QCM-D data obtained for detergents run at 2 × CMC. TX-100-mediated disruption of DOPC SLBs monitored by QCM-D was recently described 27 but was initially repeated here to confirm its membrane-disruptive behavior as a reference at the defined test concentration (2 ×CMC) (Figure 4A, line without symbols). At 2 × CMC, or 600 μM TX-100, there was an initial transient Δf drop to approximately −52 Hz and a ΔD increase of 5 × 10 −6 , lasting several minutes, which indicated detergent binding to the surface.…”

“…At 0.5 × CMC, or 150 μM, TX-100 had slight and reversible adsorption onto the SLB platform without significant membrane disruption as previously reported (Figure 5A, line without symbols). 27 The Δf signal decreased slightly to around −30 Hz and the ΔD signal increased to 3 × 10 −6 , indicating minimal detergent adsorption and induced perturbations. Upon a buffer wash, both signals returned to around baseline values.…”

Facile and scalable fabrication of exosome-mimicking nanovesicles through PEGylated lipid detergent-aided cell extrusion

“…This finding is distinct from past characterization efforts involving single-chain lipid amphiphiles, such as fatty acids, monoglycerides, and glycolipids, in which cases only micellar concentrations elicited membrane interactions. 50,51 It is likely that the two alkyl chains of the MEL PEG112 detergent establish more stable membrane association with lipid bilayers. 52 Nevertheless, it should be emphasized that MEL PEG112 detergent micelles interacted more rapidly with the SLB platform, further supporting that sufficiently high MEL PEG112 concentrations above the CMC are particularly wellsuited for cell extrusion processing.…”