Effects of nanofibrillated cellulose hydrogels on adipose tissue extract and hepatocellular carcinoma cell spheroids in freeze-drying

• Published in: Cryobiology 2019-12, Vol.91, p.137-145
• Main Authors: Auvinen, Vili-Veli, Merivaara, Arto, Kiiskinen, Jasmi, Paukkonen, Heli, Laurén, Patrick, Hakkarainen, Tiina, Koivuniemi, Raili, Sarkanen, Riina, Ylikomi, Timo, Laaksonen, Timo, Yliperttula, Marjo
• Format: Article
• Language: English
• Subjects: 3D cell culture; Adipose Tissue - chemistry; Adipose tissue extract; Carcinoma, Hepatocellular; Cell Membrane - pathology; Cell spheroids; Cellulose - pharmacology; Cryopreservation - methods; Freeze Drying; Hep G2 Cells; Humans; Hydrogels - chemistry; Hydrogels - pharmacology; Liver Neoplasms; Nanofibers - chemistry; Nanofibrillated cellulose; Spheroids, Cellular - cytology; Tissue Extracts - pharmacology; Tumor Cells, Cultured; Water - chemistry
• ISSN: 0011-2240; 1090-2392
• DOI: 10.1016/j.cryobiol.2019.09.005

The aim of this study was to evaluate the effects of two nanofibrillated cellulose (NFC) hydrogels on two human derivatives during freeze-drying. Native NFC hydrogel is a suitable platform to culture 3D cell spheroids and a hydrogel processed further, called anionic NFC (ANFC) hydrogel, is an excellent platform for controlled release of proteins. Moreover, it has been shown to be compatible with freeze-drying when correct lyoprotectants are implemented. Freeze-drying is a method, where substance is first frozen, and then vacuum dried trough sublimation of water in order to achieve dry matter without the loss of the original three-dimensional structures. The first chosen human derivative was adipose tissue extract (ATE) which is a cell-free growth factor-rich preparation capable of promoting growth of regenerative cells. The release of growth factors from the freeze-dried mixture of ATE and ANFC was compared to that of non-freeze-dried control mixtures. The release profiles remained at the same level after freeze-drying. The second derivative was hepatocellular carcinoma (HepG2) cell spheroids which were evaluated before and after freeze-drying. The 3D structure of the HepG2 cell spheroids was preserved and the spheroids retained 18% of their metabolic activity after rehydration. However, the freeze-dried and rehydrated HepG2 cell spheroids did not proliferate and the cell membrane was damaged by fusion and formation of crystals. [Display omitted]