Covalent Attachment of Fibronectin onto Emulsion‐Templated Porous Polymer Scaffolds Enhances Human Endometrial Stromal Cell Adhesion, Infiltration, and Function

Abstract

A novel strategy for the surface functionalization of emulsion‐templated highly porous (polyHIPE) materials as well as its application to in vitro 3D cell culture is presented. A heterobifunctional linker that consists of an amine‐reactive N‐hydroxysuccinimide ester and a photoactivatable nitrophenyl azide, N‐sulfosuccinimidyl‐6‐(4′‐azido‐2′‐nitrophenylamino)hexanoate (sulfo‐SANPAH), is utilized to functionalize polyHIPE surfaces. The ability to conjugate a range of compounds (6‐aminofluorescein, heptafluorobutylamine, poly(ethylene glycol) bis‐amine, and fibronectin) to the polyHIPE surface is demonstrated using fluorescence imaging, FTIR spectroscopy, and X‐ray photoelectron spectroscopy. Compared to other existing surface functionalization methods for polyHIPE materials, this approach is facile, efficient, versatile, and benign. It can also be used to attach biomolecules to polyHIPE surfaces including cell adhesion‐promoting extracellular matrix proteins. Cell culture experiments demonstrated that the fibronectin‐conjugated polyHIPE scaffolds improve the adhesion and function of primary human endometrial stromal cells. It is believed that this approach can be employed to produce the next generation of polyHIPE scaffolds with tailored surface functionality, enhancing their application in 3D cell culture and tissue engineering whilst broadening the scope of applications to a wider range of cell types.

Basic Principles of Emulsion Templating and Its Use as an Emerging Manufacturing Method of Tissue Engineering Scaffolds

“…First, they functionalised PolyHIPEs with N-sulfosuccinimidyl-6-(4 -azido-2 -nitrophenylamino hexanoate (sulfo-SANPAH)), which is a photo-linker compound that enables conjugation of biomolecules to the surfaces, and then they further functionalised the surface by covalent attachment of fibronectin to sulfo-SANPAH molecule. An improved cell attachment and infiltration of human endometrial stromal cells have been found when compared to unmodified, just sulfo-SANPAH functionalised, and fibronectin-absorbed (physically) PolyHIPEs (Richardson et al, 2019).…”

“…The suitability of the morphology of PolyHIPE matrices to be used as TE scaffolds has been well-accepted. However, as PolyHIPEs are most commonly created using w/o emulsions, they are highly hydrophobic, and lack of functionality which limits their interaction with biological tissues ( Richardson et al, 2019 ). Thus, starting from the early 2000s, researchers started to explore the ways of enhancing the biological activities of the PolyHIPE scaffolds using various methods such as chemical functionalisation ( Aldemir Dikici et al, 2019a ), incorporation of the hydrophilic particles such as HA ( Akay et al, 2004 ; Wang et al, 2016 ), incorporation of a single biologically active agent ( Ratcliffe et al, 2019 ; Richardson et al, 2019 ), or decoration PolyHIPEs with cell-derived in vitro generated ECM ( Aldemir Dikici et al, 2020 ; Table 2 ).…”

“…The solubilities of the materials that need to be removed should be considered for the selection of the washing solvent. Acetone is one of the commonly used solvents for washing of PolyHIPEs due to the high solubility of a wide range of polymers in acetone ( Caldwell et al, 2012 ; Hayward et al, 2013a ; Richardson et al, 2019 ). In our recent studies, we have used methanol instead of acetone due to it being less toxic and less destructive to crosslinked monoliths ( Aldemir Dikici et al, 2019a , b ).…”

Sterilization of PAN/Gelatine Nanofibrous Mats for Cell Growth

“…It is well-known that certain proteins present in the serum promote cell adhesion (e.g. fi bronectin [12]). Another possibility to enable cell adhesion is coating the cell culture fl asks with collagen, which is an established method to enable cell adhesion [13].…”

Inhibition of Inflammation‐Associated Thrombosis with ROS‐Responsive Heparin‐DOCA/PVAX Nanoparticles

“…Hematoxylin is alkaline, which makes the chromatin in the nucleus and the nucleic acid in the cytoplasm purple and blue. Eosin is an acid dye that makes the components of the cytoplasm and extracellular matrix reddish . The tails of normal mice show uniform purple and blue structure (Figure a).…”