Sterilization of PMMA microfluidic chips by various techniques and investigation of material characteristics

Abstract

a b s t r a c tThe sterilization of microfluidic chips is a vital step of the fabrication process prior to the customer use in biomedical applications. The aim of this study was to analyze the influence of different sterilization techniques and to compare the characteristics of the material before and after sterilization of polymethylmethacrylate (PMMA) microchips. For this, supercritical carbon dioxide (SC-CO 2 ) along with standard sterilization methods such as ultraviolet (UV), heat (autoclaving), ethylene oxide (EtO) and hydrogen peroxide (H 2 O 2 ) were applied. The treated microchips were analyzed by Scanning Electron Microscopy, Differential Scanning Calorimetry, Fourier Transform Infrared Spectroscopy and Laser Scanning Microscopy in order to ascertain any changes in the chemical structure and surface morphology. The optimum sterilization parameters for SC-CO 2 were elicited as 120 bar, 40 • C and 60 min which provided complete sterility and did not alter the main properties of the polymer along with EtO and H 2 O 2 sterilizations unlike heat and UV treatments. However, surface roughness and microchannel profiles were negatively affected. Although complete sterility was achieved, each protocol has its own strengths and weaknesses.

Evaluation of three different decontamination techniques on biofilm formation, and on physical and chemical properties of resin composites

“…All samples had similar spectra before and after the different decontamination techniques. Further, the formation of new absorption bands was not observed, nor was there any loss of signal, which suggests that there was no chemical change of the material's surface structure . Farrugia et al found some band flattening for ATR/FTIR using a longer period of decontamination (10 min) and sonication with 70% ethanol.…”

“…Further, the formation of new absorption bands was not observed, nor was there any loss of signal, which suggests that there was no chemical change of the material's surface structure. 29 Farrugia et al 13 found some band flattening for ATR/FTIR using a longer period of decontamination (10 min) and sonication with 70% ethanol. Therefore, it may be that the time of decontamination used was not long enough (1 min) in this study to cause changes in the chemical structure of the molecules of the resins tested.…”

An image J plugin for the high throughput image analysis of in vitro scratch wound healing assays

“…For these reasons, we designed a polymethyl methacrylate mold for a 24-well plate. This mold is reusable and can be sterilized using different strategies such as supercritical carbon dioxide, hydrogen peroxide gas plasma, ethylene oxide, and even γ-irradiation [31,32]. Furthermore, the mold produced more reproducible and homogeneous scratches in contrast with gaps made using only a pipette tip.…”

Synthetic Microbial Ecology: Engineering Habitats for Modular Consortia

“…The sterilized content would then be flushed out before replenishing the local niche with “fresh” cells. Alternative methods of sterilization rely on one or a combination of physical (autoclaving, UV light) and chemical treatments (ethanol, ethylene oxide, hydrogen peroxide,..) (Skaalure, 2008 ; Horst et al, 2009 ; Zhang et al, 2014 ; Yavuz et al, 2016 ), and could be applied to SLMC, for larger scales (e.g., bioreactors,..), depending on the tolerance of the materials used. Ultimately, in order to limit the risk of the occurrence of adverse events, we suggest the periodic replacement of the cells.…”