Transparent PEG-Fibrin Gel as a Flexible Tool for Cell Encapsulation

Abstract

The aim of this study was to modify the chemical structure and to optimize the composition of the fibrin gel for effective cell encapsulation. Materials and Methods. We prepared PEGylated fibrin gels using different fibrinogen concentrations (25-50 mg/ml) and PEGfibrinogen molar ratio 10:1 and 5:1 and characterized them via Fourier transform infrared spectroscopy and differential scanning calorimetry. Within the gels, we encapsulated primary culture of fibroblasts and analyzed using light and laser confocal microscopy. Results. PEGylation of fibrinogen allowed us to achieve the gel transparency and preserve its biocompatibility. We revealed that the gel prepared from PEGylated 5:1 fibrinogen (25 mg/ml) provided the most favorable microenvironment for spreading, growth, and proliferation of fibroblasts. This PEG-fibrin gel can be used for encapsulation of different cell types that is essential for various approaches in tissue engineering and diagnostic systems.

Digging deeper: structural background of PEGylated fibrin gels in cell migration and lumenogenesis

“…10 Natural brin rapidly degrades and is not transparent, so several modications have been suggested to overcome these limitations and, moreover, those have been shown to increase its angiogenic potential. [11][12][13] Among them, PEGylation (modication with functionalized polyethylene glycol (PEG)) is of particular interest.…”

“…To avoid the aforementioned problems, another common type of brin PEGylation using NHS-functionalized PEG was studied by several groups. 12,15,[18][19][20][21] This type of modication proceeding through the covalent binding of amino groups does not require protein refolding and is easy to carry out. However, despite the good results in biological experiments, no study was dedicated to the structural properties of this modication, though this knowledge could help in understanding cell-matrix interactions and possible ways to tune them.…”

Beyond 2D: effects of photobiomodulation in 3D tissue-like systems

“…7,55 The data obtained on the gel structure agreed with the earlier obtained results. 5,73 A positive correlation between fibrin gel stiffness and fibrinogen concentration was shown in previous studies that allows the preparation of fibrin gels with desired mechanical properties in a range of low Young's modulus values (<10 kPa). 74 The PEGylation is another factor, which affects gel stiffness by reducing it.…”

“…act as a base of these structures, for example, decellularized tissues [1][2][3] or hydrogels. [4][5][6] Such systems can maintain cell viability, proliferative and physiological activity, and in some cases, initiate and direct cell differentiation. 7,8 At the same time, one of the key challenges of tissue engineering is the preservation of viable cells in these constructs and transplantation of large grafts to replace extensive defects.…”

Fibrin-based Bioinks: New Tricks from an Old Dog

“…Its fibrillar structure serves as a scaffold for invading cells which bind to its fibers through cellular receptors and form capillaries. It was showed that the fiber network morphology can be significantly influenced by fibrinogen and thrombin concentrations[ 65 - 67 ], pH[ 68 ], buffers[ 5 ], incorporation of extra molecules[ 27 ], etc.…”