PDMS Compound Adsorption in Context

Soft lithography of polydimethylsiloxane (PDMS), an elastomeric polymer, has enabled rapid and inexpensive fabrication of microfluidic devices for various biotechnology applications. However, concerns remain about adsorption of compounds on PDMS surfaces because of its porosity and hydrophobicity. Here, the adsorption of 2 small fluorescent dyes of different hydrophobicity (calcein and 5- (and 6-)carboxytetramethylrhodamine (TMR)) on PDMS surface has been systematically characterized, and PDMS adsorption has been compared with 2 traditional substrates: glass and polystyrene. To characterize adsorption in a regimen that is more relevant to microfluidic applications, the adsorption and desorption of the 2 compounds in PDMS microfluidic channels under flow conditions were also studied. Results showed that there was minimal adsorption of the hydrophilic compound calcein on PDMS, whereas the more hydrophobic TMR adsorbed on PDMS up to 4 times of that on glass or polystyrene. Under flow conditions, the desorption profiles and times needed to drop desorbed compound concentrations to negligible levels (desorption time constant, 10-42 s) were characterized. In the worst case scenario, after a 4-min exposure to TMR, 4 min of continuous wash resulted in compound concentrations in the microchannels to drop to values below 2 × 10— 5 of the initial concentration. (Journal of Biomolecular Screening 2009:194-202)

[1]  J. Kasurinen.  A novel fluorescent fatty acid, 5-methyl-BDY-3-dodecanoic acid, is a potential probe in lipid transport studies by incorporating selectively to lipid classes of BHK cells. , 1992, Biochemical and biophysical research communications.

[2]  Mark Bachman,et al.  Tailoring the surface properties of poly(dimethylsiloxane) microfluidic devices. , 2004, Langmuir : the ACS journal of surfaces and colloids.

[3]  Mark Bachman,et al.  Surface-directed, graft polymerization within microfluidic channels. , 2004, Analytical chemistry.

[4]  Nancy Allbritton,et al.  Surface modification of poly(dimethylsiloxane) microfluidic devices by ultraviolet polymer grafting. , 2002, Analytical chemistry.

[5]  R. Nuzzo,et al.  Growth kinetics and morphology of self-assembled monolayers formed by contact printing 7-octenyltrichlorosilane and octadecyltrichlorosilane on Si(100) wafers. , 2004, Langmuir : the ACS journal of surfaces and colloids.

[6]  R. Nuzzo,et al.  Indirect fluorescence detection of simple sugars via high‐pH electrophoresis in poly(dimethylsiloxane) microfluidic chips , 2002, Electrophoresis.

[7]  Robert Langer,et al.  Construction of Nonbiofouling Surfaces by Polymeric Self-Assembled Monolayers , 2003 .

[8]  Sanjivanjit K. Bhal,et al.  The Rule of Five revisited: applying log D in place of log P in drug-likeness filters. , 2007, Molecular pharmaceutics.

[9]  G. Whitesides,et al.  Solvent compatibility of poly(dimethylsiloxane)-based microfluidic devices. , 2003, Analytical chemistry.

[10]  G. Whitesides,et al.  Soft Lithography. , 1998, Angewandte Chemie.

[11]  S. Fowler,et al.  Application of Nile red, a fluorescent hydrophobic probe, for the detection of neutral lipid deposits in tissue sections: comparison with oil red O. , 1985, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[12]  John P. Puccinelli,et al.  Thermal aging and reduced hydrophobic recovery of polydimethylsiloxane , 2006 .

[13]  M. Ladisch,et al.  Poly(dimethylsiloxane) (PDMS) and Silicon Hybrid Biochip for Bacterial Culture , 2003 .

[14]  G. Makrigiorgos,et al.  Detection of lipid peroxidation on erythrocytes using the excimer-forming property of a lipophilic BODIPY fluorescent dye. , 1997, Journal of biochemical and biophysical methods.

[15]  Paul Yager,et al.  A method for characterizing adsorption of flowing solutes to microfluidic device surfaces. , 2007, Lab on a chip.

[16]  G. Theodoridis,et al.  Study of multiple solid-phase microextraction combined off-line with high performance liquid chromatography: Application in the analysis of pharmaceuticals in urine , 2004 .

[17]  F. Lombardo,et al.  Experimental and computational approaches to estimate solubility and permeability in drug discovery and development settings. , 2001, Advanced drug delivery reviews.

[18]  J. Weaver,et al.  Mechanism of electroinduced ionic species transport through a multilamellar lipid system. , 1995, Biophysical journal.

[19]  Pawliszyn,et al.  Determination of distribution constants between a liquid polymeric coating and water by a solid-phase microextraction technique with a flow-through standard water system , 2000, Analytical chemistry.

[20]  K. Imamura,et al.  On the adsorption of proteins on solid surfaces, a common but very complicated phenomenon. , 2001, Journal of bioscience and bioengineering.

[21]  Charles Tanford,et al.  Physical Chemistry of Macromolecules , 1961 .

[22]  George M. Whitesides,et al.  Selective Deposition of Proteins and Cells in Arrays of Microwells , 2001 .

[23]  D. Beebe,et al.  PDMS absorption of small molecules and consequences in microfluidic applications. , 2006, Lab on a chip.

[24]  S. Quake,et al.  From micro- to nanofabrication with soft materials. , 2000, Science.