Complete inclusion of bioactive molecules and particles in polydime-thylsiloxane: a straightforward process under mild conditions
Pith reviewed 2026-05-24 17:14 UTC · model grok-4.3
The pith
Biomolecules remain active when embedded as liquid phases in PDMS via slow curing under mild conditions.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
By applying a slow curing process, biomolecules can be incorporated via a simple process as liquid stable phases inside a polydimethylsiloxane matrix under mild conditions, preserving their biochemical properties without loss due to adsorption at the liquid-polymer interface.
What carries the argument
The slow curing process that enables complete inclusion of biomolecules as stable liquid phases inside the PDMS matrix.
If this is right
- The PDMS matrix protects the inclusions from external stimuli.
- These soft liquid composite materials are new tools of interest for robotics, microfluidics, diagnostics and chemical microreactors.
- The process is carried out under mild conditions with regards to temperature, pH and relative humidity and is thus suitable for application to biological entities.
Where Pith is reading between the lines
- Such composites could support distributed enzymatic reactions within flexible microfluidic channels.
- The liquid-phase stability might allow repeated use of embedded catalysts without polymer-induced degradation.
- Testing the method with living cells could reveal whether the approach extends to hybrid bio-synthetic systems.
Load-bearing premise
The slow curing process allows complete inclusion of the biomolecules as stable liquid phases inside the PDMS matrix without causing damage or irreversible adsorption at the interface.
What would settle it
Direct measurement of significant loss in enzymatic activity or fluorescence after curing, or imaging evidence of adsorption at the polymer interface, would falsify the claim of preserved properties and complete inclusion.
Figures
read the original abstract
By applying a slow curing process, we show that biomolecules can be incorporated via a simple process as liquid stable phases inside a polydimethylsiloxane (PDMS) matrix. The process is carried out under mild conditions with regards to temperature, pH and relative humidity, and is thus suitable for application to biological entities. Fluorescence and enzymatic activity measurements, show that the biochemical properties of the proteins and enzyme tested are preserved, without loss due to adsorption at the liquid-polymer interface. Protected from external stimuli by the PDMS matrix, these soft liquid composite materials are new tools of interest for robotics, microfluidics, diagnostics and chemical microreactors.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript describes a slow-curing process under mild conditions (temperature, pH, humidity) to incorporate biomolecules and particles as stable liquid phases inside a PDMS matrix. Fluorescence and enzymatic activity data are presented to support the claim that biochemical properties are preserved without loss attributable to adsorption at the liquid-polymer interface, yielding protected composite materials for robotics, microfluidics, diagnostics, and microreactors.
Significance. If the central claims of complete bulk-liquid inclusion and activity preservation are substantiated, the method would provide a simple, mild-condition route to embed sensitive biological entities in PDMS, enabling new protected soft composites. The work is experimental and process-oriented with no parameter-free derivations or machine-checked proofs.
major comments (2)
- [Abstract] Abstract: The claim that fluorescence and enzymatic activity measurements demonstrate preservation 'without loss due to adsorption at the liquid-polymer interface' is not supported by the data as described. Bulk activity/fluorescence signals cannot distinguish complete inclusion from interfacial adsorption if the adsorbed fraction retains function (a plausible outcome under mild conditions). No controls such as deliberate surface-adsorption assays, post-cure leaching quantification, or interface-specific spectroscopy are referenced to isolate this possibility.
- [Abstract] Abstract and methods description: No raw data, error bars, replicate numbers, or detailed protocols are provided in the available text, preventing evaluation of the quantitative support for 'complete inclusion' and activity preservation. This is load-bearing for the central experimental claim.
Simulated Author's Rebuttal
We thank the referee for their constructive comments on our manuscript. We address each major comment point by point below, indicating where revisions will be made.
read point-by-point responses
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Referee: [Abstract] Abstract: The claim that fluorescence and enzymatic activity measurements demonstrate preservation 'without loss due to adsorption at the liquid-polymer interface' is not supported by the data as described. Bulk activity/fluorescence signals cannot distinguish complete inclusion from interfacial adsorption if the adsorbed fraction retains function (a plausible outcome under mild conditions). No controls such as deliberate surface-adsorption assays, post-cure leaching quantification, or interface-specific spectroscopy are referenced to isolate this possibility.
Authors: We agree that bulk measurements of fluorescence and enzymatic activity do not definitively exclude the possibility that an adsorbed fraction at the interface retains function. The experimental design relies on the slow-curing process to achieve bulk liquid-phase inclusion, but the current data presentation does not include explicit controls to isolate interfacial effects. We will revise the abstract to qualify or remove the claim regarding 'without loss due to adsorption at the liquid-polymer interface' and add a discussion of this limitation, drawing on the process conditions and any available supporting observations from the work. revision: yes
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Referee: [Abstract] Abstract and methods description: No raw data, error bars, replicate numbers, or detailed protocols are provided in the available text, preventing evaluation of the quantitative support for 'complete inclusion' and activity preservation. This is load-bearing for the central experimental claim.
Authors: The manuscript contains figures presenting fluorescence and activity data, but we acknowledge that the text as provided to the referee lacks explicit details on raw data, error bars, replicate numbers, and full protocols. We will expand the methods section with detailed protocols, specify replicate numbers and statistical analysis, ensure error bars are clearly indicated in figures, and provide access to raw data in the revised submission to allow full evaluation of the quantitative claims. revision: yes
Circularity Check
No circularity: experimental process with direct measurements only
full rationale
The paper is a methods description of an experimental incorporation process for biomolecules into PDMS under mild slow-curing conditions. It reports fluorescence and enzymatic activity data to support preservation of biochemical properties. No equations, fitted parameters, predictions, derivations, or self-citations appear in the provided text or abstract. The central claim rests on direct experimental observations rather than any reduction to inputs by construction. Per the rules, this is the normal self-contained case and receives score 0 with empty steps list.
Axiom & Free-Parameter Ledger
Reference graph
Works this paper leans on
-
[1]
Song, H.; Tice, J. D.; Ismagilov, R. F. A Microfluidic System for Controlling Reaction Net- works in Time. Angewandte Chemie 2003, 115, 792-796
work page 2003
-
[2]
A Strain‐Regulated, Refillable Elastic Patch for Controlled Release
Bongsoo, K.; SangHyuk, Y.; Kim Yong‐Jin; Jaeyoon, P.; Byunghoon, K.; Seungjoo, H.; Kang Sun‐Woong; Keonwook, K.; Unyong, J. A Strain‐Regulated, Refillable Elastic Patch for Controlled Release. Adv. Mater. Interfaces 2016, 3, 1500803
work page 2016
-
[3]
Stretchable electronics based on Ag- PDMS composites
Larmagnac, A.; Eggenberger, S.; Janossy, H.; Vörös, J. Stretchable electronics based on Ag- PDMS composites. Sci. Rep. 2014, 4, 7254
work page 2014
-
[4]
W.; Boltyanskiy, R.; Allen, B.; Jensen, K
Style, R. W.; Boltyanskiy, R.; Allen, B.; Jensen, K. E.; Foote, H. P.; Wettlaufer, J. S.; Du- fresne, E. R. Stiffening solids with liquid inclusions. Nat Phys 2015, 11, 82-87
work page 2015
-
[5]
Kim, H. K.; Lee, D.; Lim, S. Wideband -Switchable Metamaterial Absorber Using Injected Liquid Metal. Scientific Reports 2016, 6, 31823
work page 2016
-
[6]
S. Khan; S. Tinku; L. Lorenzelli; R. S. Dahiya Flexible Tactile Sensors Using Screen-Printed P(VDF-TrFE) and MWCNT/PDMS Composites. IEEE Sensors Journal 2015, 15, 3146-3155
work page 2015
-
[7]
Sadasivuni, K. K.; Mohiuddin, M.; Gao, X.; Akther, A.; Mun, S.; Kim, J., In Cellulose/PDMS hybrid material for actuating lens; 2015; Vol. 9434, pp 94340K-94340K-6
work page 2015
-
[8]
Deployable Soft Composite Structures
Wang, W.; Rodrigue, H.; Ahn, S. Deployable Soft Composite Structures. Scientific Reports 2016, 6, 20869
work page 2016
-
[9]
Martinez, R. V.; Branch, J. L.; Fish, C. R.; Lihua, J.; Shepherd, R. F.; Nunes, R. M.; Zhigang, S.; Whitesides, G. M. Robotic Tentacles with Three‐Dimensional Mobility Based on Flexible Elastomers. Adv Mater 2012, 25, 205-212
work page 2012
-
[10]
Iino, R.; Matsumoto, Y.; Nishino, K.; Yamaguchi, A.; Noji, H. Design of a large -scale femtoliter droplet array for single -cell analysis of drug -tolerant and drug -resistant bacteria. Frontiers in Microbiology 2013, 4
work page 2013
-
[11]
Nanoliter-Scale Protein Crystallization and Screening with a Microfluidic Droplet Robot
Zhu, Y.; Zhu, L.; Guo, R.; Cui, H.; Ye, S.; Fang, Q. Nanoliter-Scale Protein Crystallization and Screening with a Microfluidic Droplet Robot. Scientific Reports 2014, 4, 5046
work page 2014
-
[12]
Walt, D. R. Protein measurements in microwells. Lab Chip 2014, 14, 3195-3200
work page 2014
-
[13]
Bose, S.; Wan, Z.; Carr, A.; Rizvi, A. H.; Vieira, G.; Pe'er, D. Scalable microfluidics for single cell RNA printing and sequencing. Genome Biol. 2015, 16, 120
work page 2015
-
[14]
M.; Mazutis, L.; Akartuna, I.; Tallapragada, N.; Veres, A.; Li, V
Klein, A. M.; Mazutis, L.; Akartuna, I.; Tallapragada, N.; Veres, A.; Li, V. Droplet barcod- ing for single-cell transcriptomics applied to embryonic stem cells. Cell 2015, 161, 1187-1201
work page 2015
-
[15]
Lach, S.; Yoon, S. M.; Grzybowski, B. A. Tactic, reactive, and functional droplets outside of equilibrium. Chem. Soc. Rev. 2016, 45, 4766-4796
work page 2016
-
[16]
Simple, robust storage of drops and fluids in a microfluidic device
Boukellal, H.; Selimovic, S.; Jia, Y.; Cris tobal, G.; Fraden, S. Simple, robust storage of drops and fluids in a microfluidic device. Lab Chip 2009, 9, 331-338
work page 2009
-
[17]
Stone, H. A.; Stroock, A. D.; Ajdari, A. ENGINEERING FLOWS IN SMALL DEVICES. Annu. Rev. Fluid Mech. 2004, 36, 381-411
work page 2004
-
[18]
Song, H.; C hen, D. L.; Ismagilov, R. F. Reactions in Droplets in Microfluidic Channels. Angewandte Chemie International Edition 2006, 45, 7336-7356
work page 2006
-
[19]
J., Warren J., Meldrum F.C., Precipitation of Calcium Carbonate in Con- finement
Loste E., Park R. J., Warren J., Meldrum F.C., Precipitation of Calcium Carbonate in Con- finement. Advanced Functional Materials 14(12):1211-1220
-
[20]
Sensors and Actuators B: Chemical 2012161(1), 1176-1183
Kobayashi, T., Konishi, S.; Microfluidic chip with serially connected filters for improve- ment of collection efficiency in blood plasma separation. Sensors and Actuators B: Chemical 2012161(1), 1176-1183
-
[21]
Jin, B.; Esteva-Font, C.; Verkman, A. S. Droplet-based microfluidic platform for measure- ment of rapid erythrocyte water transport. Lab Chip 2015, 15, 3380-3390
work page 2015
-
[22]
Taylor, N.; Elbaum-Garfinkle, S.; Vaidya, N.; Zhang, H.; Stone, H. A.; Brangwynne, C. P. Biophysical characterization of organelle -based RNA/protein liquid phases using microfluid- ics. Soft Matter 2016, 12, 9142-9150
work page 2016
-
[23]
Reconfigurable plasmonic devices using liquid metals
Wang, J.; Liu, S.; Nahata, A. Reconfigurable plasmonic devices using liquid metals. Opt. Express 2012, 20, 12119-12126
work page 2012
-
[24]
Liquid metal sponges for mechanically durable, all -soft, electrical conductors
Liang, S.; Li, Y.; Chen, Y.; Yang, J.; Zhu, T.; Zhu, D.; He, C.; Liu, Y.; Handschuh -Wang, S.; Zhou, X. Liquid metal sponges for mechanically durable, all -soft, electrical conductors. J. Mater. Chem. C 2017, 5, 1586-1590
work page 2017
-
[25]
Chipara, A. C.; Owuor, P. S.; Sanjit, B.; Gustavo, B.; Asif, S. A. S.; Mircea, C.; Robert, V.; Jun, L.; Galvao, D. S.; Tiwary, C. S.; Ajayan, P. M. Structural Reinforcement through Liquid Encapsulation. Adv. Mater. Interfaces 2017, 4, 1600781
work page 2017
-
[26]
Lawton, R. A.; Price, C. R.; Runge, A . F.; Doherty III, W. J.; Saavedra, S. S. Air plasma treatment of submicron thick PDMS polymer films: effect of oxidation time and storage condi- tions. Colloids Surf. Physicochem. Eng. Aspects 2005, 253, 213-215
work page 2005
-
[27]
Process and material properties of polydimethylsiloxane (PDMS) for Optical MEMS
Schneider, F.; Draheim, J.; Kamberger, R.; Wallrabe, U. Process and material properties of polydimethylsiloxane (PDMS) for Optical MEMS. Sensors and Actuators A: Physical 2009, 151, 95-99
work page 2009
-
[28]
Mata, A.; Fleischman, A. J.; Roy, S. Characterization of Polydimethylsiloxane (PDMS) Properties for Biomedical Micro/Nanosystems. Biomed. Microdevices 2005, 7, 281-293
work page 2005
-
[29]
Morteza, A.; Sahar, S.; Nelson, B. J.; Metin, S. Recent Advances in Wearable Transdermal Delivery Systems. Adv Mater 2018, 30, 1704530
work page 2018
-
[30]
Wu, D.; Zhao, B.; Dai, Z.; Qin, J.; Lin, B. Gr afting epoxy-modified hydrophilic polymers onto poly(dimethylsiloxane) microfluidic chip to resist nonspecific protein adsorption. Lab Chip 2006, 6, 942-947
work page 2006
-
[31]
Roach, L. S.; Song, H.; Ismagilov, R. F. Controlling Nonspecific Protein Adsorption in a Plug-Based Microfluidic System by Controlling Interfacial Chemistry Using Fluorous -Phase Surfactants. Anal. Chem. 2005, 77, 785-796
work page 2005
-
[32]
From Protein Features to Sensing Surfaces
Faccio, G. From Protein Features to Sensing Surfaces. Sensors 2018, 18
work page 2018
-
[33]
R estraining non-specific adsorption of protein using Parylene C-caulked polydimethylsiloxane
Liu, Y.; Zhang, L.; Wu, W.; Zhao, M.; Wang, W. R estraining non-specific adsorption of protein using Parylene C-caulked polydimethylsiloxane. Biomicrofluidics 2016, 10, 024126
work page 2016
-
[34]
Chandradoss, S. D.; Haagsma, A. C.; Lee, Y. K.; Hwang, J.; Nam, J.; Joo, C. Surface Pas- sivation for Single-molecule Protein Studies. Journal of Visualized Experiments: JoVE 2014, 50549
work page 2014
-
[35]
Keir, B.; Wu Min‐Hsien; Zheng, C.; Zhangfeng, C.; Watts, J. F.; Baker, M. A. Simple sur- face treatments to modify protein adsorption and cell attachment properties within a poly(di- methylsiloxane) micro‐bioreactor. Surf. Interface Anal. 2006, 38, 198-201
work page 2006
-
[36]
Herrmann, M.; Roy, E.; Veres, T.; Tabrizian, M. Microfluidic ELISA on non -passivated PDMS chip using magnetic bead transfer inside dual networks of channels. Lab Chip 2007, 7, 1546-1552
work page 2007
-
[37]
McDonald, J. C.; Whitesides, G. M. Poly(dimethylsiloxane) as a Material for Fabricating Microfluidic Devices. Acc. Chem. Res. 2002, 35, 491-499
work page 2002
-
[38]
Vagenende, V.; Yap, M. G. S.; Trout, B. L. Mechanisms of Protein Stabilization and Pre- vention of Protein Aggregation by Glycerol. Biochemistry (N. Y.) 2009, 48, 11084-11096
work page 2009
-
[39]
Stepanenko, O. V.; Stepanenko, O. V.; Kuznetsova, I. M.; Verkhusha, V. V.; Turoverov, K. K. Beta-Barrel Scaffold of Fluorescent Proteins: Folding, Stability and Role in Chromophore Formation. International review of cell and molecular biology 2013, 302, 221-278
work page 2013
-
[40]
Quiquampoix H., A stepwise approach to the understanding of extracellular enzyme activity in soil. I. Effect of electrostatic interactions on the conformation of a beta-D-glucosidase ad- sorbed on different mineral surfaces. Biochimie, 1987, Jun-Jul; 69(6-7):753-63
work page 1987
-
[41]
Baugh L., Vogel V., Structural changes of fibronectin adsorbed to model surfaces probed by fluorescence resonance energy transfer, J. Biomed. Mater. Res . A, 2004, Jun 1; 69(3):525 - 34
work page 2004
-
[42]
Chumbimuni-Torres, K.; Coronado, R. E.; Mfuh, A. M.; Castro-Guerrero, C.; Silva, M. F.; Negrete, G. R.; Bizios, R.; Garcia, C. D. Adsorption of proteins to thin -films of PDMS and its effect on the adhesion of human endothelial cells. RSC Adv. 2011, 1, 706-714
work page 2011
-
[43]
Cai, Z.; Qiu, W.; Shao, G., Wang, W.; A new fabrication method for all-PDMS waveguides, Sensors and Actuators A: Physical 2013 204 44-47
work page 2013
-
[44]
Rodríguez Couto, S.; Toca Herrera, J. L. Industrial and biotechnologic al applications of laccases: A review. Biotechnol. Adv. 2006, 24, 500-513
work page 2006
-
[45]
My voyage of discovery to proteins in flatland …and beyond
Norde, W. My voyage of discovery to proteins in flatland …and beyond. Colloids and Sur- faces B: Biointerfaces 2008, 61, 1-9
work page 2008
-
[46]
Heterologous laccase pro- duction and its role in industrial applications
Piscitelli, A.; Pezzella, C.; Giardina, P.; Farac o, V.; Sannia, G. Heterologous laccase pro- duction and its role in industrial applications. Bioengineered Bugs 2010, 1, 252-262
work page 2010
-
[47]
Fungal laccases - occurrence and properties
Baldrian, P. Fungal laccases - occurrence and properties. FEMS Microbiol. Rev. 2006, 30, 215-242
work page 2006
-
[48]
Heyries, K. A.; Marquette, C. A.; Blum, L. J. Straightforward Protein Immobilization on Sylgard 184 PDMS Microarray Surface. Langmuir 2007, 23, 4523-4527
work page 2007
-
[49]
van Reenen, A.; de Jong, A. M.; den Toonder, Jaap M. J.; Prins, M. W. J. Integrated lab - on-chip biosensing system s based on magnetic particle actuation - a comprehensive review. Lab Chip 2014, 14, 1966-1986
work page 2014
-
[50]
Chong, W. H.; Chin, L. K.; Tan, R. L. S.; Wang, H.; Liu, A. Q.; Chen, H. Stirring in Sus- pension: Nanometer -Sized Magnetic Stir Bars. Angewandte Chemie Intern ational Edition 2013, 52, 8570-8573
work page 2013
-
[51]
Long, Z.; Shetty, A. M.; Solomon, M. J.; Larson, R. G. Fundamentals of magnet -actuated droplet manipulation on an open hydrophobic surface. Lab Chip 2009, 9, 1567-1575
work page 2009
-
[52]
Innocenti Malini R., Lesage J., Toncelli C., Fortunato G., Rossi R. M., Spano F., Crosslink- ing dextran electrospun nanofibers via borate chemistry: Proof of concept for wound patches, European Polymer Journal, 110 (2019), 276-282. Supporting Information Complete inclusion of bioactive molecules and particles in polydi- methylsiloxane: a straightforward ...
work page 2019
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