PMID- 19324392
OWN - NLM
STAT- MEDLINE
DCOM- 20090710
LR  - 20161125
IS  - 1879-1298 (Electronic)
IS  - 0045-6535 (Linking)
VI  - 76
IP  - 1
DP  - 2009 Jun
TI  - Development of a dynamic delivery method for in vitro bioassays.
PG  - 83-90
LID - 10.1016/j.chemosphere.2009.02.023 [doi]
AB  - Measuring the biological activity of hydrophobic chemicals using in vitro assays 
      is challenging because their aqueous solubility is low and the high density of 
      bio-suspensions strongly decreases the bioavailability of hydrophobic pollutants. 
      Dynamic dosing by partitioning from a stable polymer has a potential to overcome 
      these limitations. Poly(dimethylsiloxane) (PDMS) was chosen due to its documented 
      bio-compatibility and excellent partitioning properties. PDMS sheets were loaded 
      with five polycyclic aromatic hydrocarbons (PAHs) and then immersed in model 
      bio-suspensions composed of membrane vesicles ("chromatophores", composed of 30% 
      lipids and 70% proteins) isolated from the photosynthetic bacterium Rhodobacter 
      sphaeroides or phospholipid bilayer vesicles (liposomes) composed of 
      palmitoyl-oleoyl phosphatidylcholine (POPC). Method development included the 
      determination of partition coefficients between chromatophores or liposomes and 
      water, desorption rate constants from PDMS to bio-suspensions, and diffusion 
      resistances in both PDMS and bio-suspensions. The release of the PAHs from the 
      PDMS into the bio-suspensions was measured and modeled as a combination of 
      diffusion in pure water and diffusion in a completely mixed solvent composed of 
      water and bio-suspensions. The mass transfer resistance for the release was lower 
      in the PDMS than in the tested solutions, which demonstrates that PDMS can 
      efficiently deliver PAHs even to dense biosuspensions. The contribution of 
      aqueous diffusion to the mass transfer decreased with increasing hydrophobicity 
      of the PAHs indicating that hydrophobic chemicals are efficiently transported 
      with suspended biomaterial. The passive dosing system is versatile and offers a 
      number of applications. Promising are tests with instantaneous response, where 
      the time-dependent effect can be translated to concentration-effect curves but 
      the system is also applicable for assuring constant dosing for longer-term 
      testing.
FAU - Kwon, Jung-Hwan
AU  - Kwon JH
AD  - Department of Environmental Toxicology (Utox), Swiss Federal Institute of Aquatic 
      Science and Technology (Eawag), Dubendorf, Switzerland. jhkwon@ajou.ac.kr
FAU - Wuethrich, Thomas
AU  - Wuethrich T
FAU - Mayer, Philipp
AU  - Mayer P
FAU - Escher, Beate I
AU  - Escher BI
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20090325
PL  - England
TA  - Chemosphere
JT  - Chemosphere
JID - 0320657
RN  - 0 (Dimethylpolysiloxanes)
RN  - 0 (Environmental Pollutants)
RN  - 0 (Liposomes)
RN  - 0 (Polycyclic Aromatic Hydrocarbons)
RN  - 059QF0KO0R (Water)
RN  - 63148-62-9 (baysilon)
SB  - IM
MH  - Adsorption
MH  - Algorithms
MH  - Biological Assay/*methods
MH  - Chromatophores/chemistry
MH  - Diffusion
MH  - Dimethylpolysiloxanes/*chemistry
MH  - Environmental Pollutants/*analysis
MH  - Hydrophobic and Hydrophilic Interactions
MH  - Liposomes/chemistry
MH  - Models, Chemical
MH  - Polycyclic Aromatic Hydrocarbons/*analysis
MH  - Time Factors
MH  - Water/chemistry
EDAT- 2009/03/28 09:00
MHDA- 2009/07/11 09:00
CRDT- 2009/03/28 09:00
PHST- 2008/12/10 00:00 [received]
PHST- 2009/02/06 00:00 [revised]
PHST- 2009/02/06 00:00 [accepted]
PHST- 2009/03/28 09:00 [entrez]
PHST- 2009/03/28 09:00 [pubmed]
PHST- 2009/07/11 09:00 [medline]
AID - S0045-6535(09)00184-2 [pii]
AID - 10.1016/j.chemosphere.2009.02.023 [doi]
PST - ppublish
SO  - Chemosphere. 2009 Jun;76(1):83-90. doi: 10.1016/j.chemosphere.2009.02.023. Epub 
      2009 Mar 25.