title: Microchannel acoustophoresis does not impact survival or function of microglia, leukocytes or tumor cells.
abstract: BACKGROUND
  The use of acoustic forces to manipulate particles or cells at the microfluidic scale (i.e. acoustophoresis), enables non-contact, label-free separation based on intrinsic cell properties such as size, density and compressibility. Acoustophoresis holds great promise as a cell separation technique in several research and clinical areas. However, it has been suggested that the force acting upon cells undergoing acoustophoresis may impact cell viability, proliferation or cell function via subtle phenotypic changes. If this were the case, it would suggest that the acoustophoresis method would be a less useful tool for many cell analysis applications as well as for cell therapy.
  
  
  METHODS
  We investigate, for the first time, several key aspects of cellular changes following acoustophoretic processing. We used two settings of ultrasonic actuation, one that is used for cell sorting (10 Vpp operating voltage) and one that is close to the maximum of what the system can generate (20 Vpp). We used microglial cells and assessed cell viability and proliferation, as well as the inflammatory response that is indicative of more subtle changes in cellular phenotype. Furthermore, we adapted a similar methodology to monitor the response of human prostate cancer cells to acoustophoretic processing. Lastly, we analyzed the respiratory properties of human leukocytes and thrombocytes to explore if acoustophoretic processing has adverse effects.
  
  
  RESULTS
  BV2 microglia were unaltered after acoustophoretic processing as measured by apoptosis and cell turnover assays as well as inflammatory cytokine response up to 48 h following acoustophoresis. Similarly, we found that acoustophoretic processing neither affected the cell viability of prostate cancer cells nor altered their prostate-specific antigen secretion following androgen receptor activation. Finally, human thrombocytes and leukocytes displayed unaltered mitochondrial respiratory function and integrity after acoustophoretic processing.
  
  
  CONCLUSIONS
  We conclude that microchannel acoustophoresis can be used for effective continuous flow-based cell separation without affecting cell viability, proliferation, mitochondrial respiration or inflammatory status.
authors.affiliation: Neuronal Survival Unit, Department of Experimental Medical Science, Wallenberg Neuroscience Center, Lund University, Lund, Sweden.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Burguillos
authors.forename: Cecilia
authors.initials: C
authors.lastname: Magnusson
authors.forename: Maria
authors.initials: M
authors.lastname: Nordin
authors.forename: Andreas
authors.initials: A
authors.lastname: Lenshof
authors.forename: Per
authors.initials: P
authors.lastname: Augustsson
authors.forename: Magnus J
authors.initials: MJ
authors.lastname: Hansson
authors.forename: Eskil
authors.initials: E
authors.lastname: Elmér
authors.forename: Hans
authors.initials: H
authors.lastname: Lilja
authors.forename: Patrik
authors.initials: P
authors.lastname: Brundin
authors.forename: Thomas
authors.initials: T
authors.lastname: Laurell
authors.forename: Tomas
authors.initials: T
authors.lastname: Deierborg
mesh_terms: D001773:Blood Cells / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival; D006801:Humans; D007962:Leukocytes / Q000378:metabolism*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods; D017628:Microglia / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D009369:Neoplasms / Q000378:metabolism*; D014465:Ultrasonics