The effect of micromachining process to the biocompatibility of 3C-SiC membranes

Abstract

3C-Silicon Carbide (SiC) has been identified as a potential biomaterial for implantable devices. The prospect of 3C-SiC membrane as the working component for BioMEMS in in-vitro blood pressure sensing could be a new challenge for biomedical engineers. Although, 3C-SiC is known to be biocompatible, but the micromachining process normally used in semiconductor industry might alter the biocompatibility of 3C-SiC. In this study, we investigate the biocompatibility of 3C-SiC which had been subjected to Potassium Hydroxide (KOH) wet etching and reactive ion etching (RIE) using tetrafluoromethane (CF4). The Chinese Hamster Ovary (CHO) cells were directly cultured onto the prepared samples of 3C-SiC, Si and controls to investigate 3C-SiC biocompatibility. The cells were detached from the substrates and grown further in 6 well plates for another 24 hours at 37°C with 5% CO2 and 95% relative humidity for further testing. Cell viability percentage was determined by Trypan Blue exclusion technique which revealed the preference of the cells to grow and to proliferate on the treated SiC samples. However, the results could be inaccurate due to the nature of the testing which compromises the further ability of the cells to proliferate. Thus, a comparison was made by using Methylthiazolyldiphenyltetrazolium bromide (MTT) assay, a typical cytotoxicity assay, and also PrestoBlue™ reagent (which is the state-of-the-art assay for biocompatibility determination) to confirm the cell viability on the treated and untreated SiC. Thus, the results showed that the cells proliferated better on surface of the 3C-SiC treated with halogenated plasma which indicate the enhancement of biocompatibility of the semiconductor material due to the RIE.