Organ-on-a-chip technologies show exponential growth driven by the need to reduce
the number of experimental animals and develop physiologically relevant human models
for testing drugs. In vitro, microfluidic devices should be carefully designed and
fabricated to provide reliable tools for modeling physiological or pathological conditions
and assessing, for example, drug delivery through biological barriers. The aim of
the current study was to optimize the utilization of three existing skin-on-a-chip
microfluidic diffusion chambers with various designs. For this, different perfusion
flow rates were compared using cellulose acetate membrane, polyester membrane, excised
rat skin, and acellular alginate scaffold in the chips. These diffusion platforms
were integrated into a single-channel microfluidic diffusion chamber, a multi-channel
chamber, and the LiveBox2 system. The experimental results revealed that the 40 µL/min
flow rate resulted in the highest diffusion of the hydrophilic model formulation (2%
caffeine cream) in each system. The single-channel setup was used for further analysis
by computational fluid dynamics simulation. The visualization of shear stress and
fluid velocity within the microchannel and the presentation of caffeine progression
with the perfusion fluid were consistent with the measured data. These findings contribute
to the development and effective application of microfluidic systems for penetration
testing.
