Biological properties of macroporous cryostructurate based on extracellular matrix components

Abstract

Objective: to study the biological properties of macroporous cryostructurate from multicomponent concentrated collagen-containing solution (MCCS) as a promising matrix for the formation of cell- and tissue-engineered constructs.Materials and methods. A macroporous spongy carrier was obtained by cryostructuring of collagencontaining extract, prepared by acetic acid hydrolysis of chicken connective tissue (BIOMIR Service, Russian Federation). N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide (Sigma-Aldrich, USA) was used to make the cryostructurate water insoluble. The micromorphology of the sponge surface was studied using scanning electron microscopy. The cytotoxicity of the carrier was evaluated by reaction of the mouse NIH 3T3 fibroblast cell culture using automated microscope IncuCyte ZOOM (EssenBioscience, USA). Biocompatibility of the macroporous carrier was studied on cultures of human adipose tissue-derived mesenchymal stromal cells (AD-MSC), human hepatocellular carcinoma cell line HepG2 and human umbilical vein endothelial cell line EA.hy926. The metabolic activity of cells was determined using PrestoBlue™ reagents (Invitrogen™, USA). Cell population development during long-term cultivation of the cell-engineered construct (CEC) was assessed by fluorescencelifetime imaging microscopy over the entire surface of the sample using a Leica Dmi8 inverted microscope with Leica Thunder software (Leica Microsystems, Germany).Results. Optical microscopy and scanning electron microscopy (SEM) showed the presence of pores of different sizes in the resulting biopolymer material: large pores with 237 ± 32 μm diameter, medium-sized pores with 169 ± 23 μm diameter, and small-sized pores with 70 ± 20 μm diameter; large and medium-sized pores were predominant. The studied media did not exhibit cytotoxicity. Cell adhesion and proliferation on the surface of the material and their penetration into the underlying layers during long-term cultivation were observed. The highest metabolic activity of the cells was observed for human AD-MSC on day 14, which corresponds to the normal dynamics of development of a population of cells of this type. The functional activity of HepG2 cells – albumin and urea production – was shown in the liver CEC model.Conclusion. The good adhesion and active proliferation that were shown for the three cell types indicate that the resulting biopolymer carrier is biocompatible, and that the spread of the cells into the inner volume of the sponge and active population of the sponge under prolonged culturing indicates that this material can be used to create cell- and tissue-engineered constructs.

Keywords

• cryogenic structuring
• collagen
• tissue engineering