Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 45 8 2016 10 10 1054 1063 Ladan DELPHI Dept. of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran, Iran Houri SEPEHRI Dept. of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran, Iran Elahe MOTEVASELI Dept. of Medical Genetics, Tehran University of Medical Sciences, Tehran, Iran Mohammad Reza KHORRAMIZADEH Endocrinology and Metabolic Research Institute, Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran 2016 08 28 2016 08 28 Background: Collagen-based three-dimensional (3D) in vitro systems have been introduced to study the physiological states of cells. As a biomolecule, collagen is usually extracted from terrestrial animals whilst aquatic animals like squid contain large amounts of collagen. Methods: In order to make effective use of marine organisms, we selected Persian Gulf squid in 2015 to extract the required collagen. Then, a 3D culture system based on the extracted collagen was applied to investigate cellular mechanisms in a native microenvironment. The formed collagen gel was used to investigate the growth of MDA-MB-231 breast cancer cells as well as responses to pectic acid. Results: The results revealed that the extracted collagen contained α, ß and γ components with high water holding capacity. This collagen formed a gel-like structure, which could promote the proliferation of MDA-MB-231 breast cancer cells. The MDA-MB-231 cells’ viability in presence of pectic acid, demonstrating the cells’ behavior in a 3D culture system. Conclusion: It seems that the collagen extracted from squid skin has type I collagen properties. It might be used as a substrate in 3D cell culture systems.     https://ijph.tums.ac.ir/index.php/ijph/article/view/7607 https://ijph.tums.ac.ir/index.php/ijph/article/download/7607/5513