Zein films as substrates for cell attachment

Circulating tumor cells (CTCs) are cells that have shed into the vasculature from a primary tumor and circulate in the blood stream. Circulating tumor cells play an important role in metastasis. The long term goal of this project is to capture and remocve CTC’s from the blood stream. Numerous studies on glutamine metabolism in cancer indicate that many tumors are avid glutamine consumers in vivo and in vitro. Prolamins are a group of plant seed proteins having high glutamine content. A main example is corn zein. Zein has been reported to support cell attachment. The main hypothesis in this work was that zein is able to support attachment of cancer (HeLa) cells. In this work, HeLa cells were grown on glass slides coated with zein films. It was reported that the hydrophobicity and topography of substrates are important for cell attachment. Therefore, a secondary hypothesis was that the hydrophobicity and topography of zein substrates could be optimized for cancer cell attachment. The hydrophobicity of zein films had been observed to reflect the hydrophobicity of its underlying substrate. Thus, glass slides were treated with oxygen plasma to modulate their hydrophobicity. The surface hydrophobicity of substrates intended for cell attachment was measured with a CAM 200 Goniometer. Topographic features were examined by MFP-3D AFM. Results showed that HeLa cells were observed to adhere and grow on zein substrates cast on oxygen treated plasma glass slides. The glutamine effect of zein on HeLa cells was evidenced by the cells unfavorable response when zein was deamidated by surface treatment with hydrochloric acid. HeLa cells on zein films developed elongated cells at 24h and 48 h of incubation. Zein was believed to support HeLa cells attachment. Results of this work are expected to be useful in designing bio surfaces for isolation of cancer cells