A Three-Dimensional Bioprinted Copolymer Scaffold with Biocompatibility and Structural Integrity for Potential Tissue Regeneration Applications

Abstract

The present study was to investigate the rheological property, printability, and cell viability of alginate–gelatin composed hydrogels as a potential cell-laden bioink for three-dimensional (3D) bioprinting applications. The 2 g of sodium alginate dissolved in 50 mL of phosphate buffered saline solution was mixed with different concentrations (1% (0.5 g), 2% (1 g), 3% (1.5 g), and 4% (2 g)) of gelatin, denoted as GBH-1, GBH-2, GBH-3, and GBH-4, respectively. The properties of the investigated hydrogels were characterized by contact angle goniometer, rheometer, and bioprinter. In addition, the hydrogel with a proper concentration was adopted as a cell-laden bioink to conduct cell viability testing (before and after bioprinting) using Live/Dead assay and immunofluorescence staining with a human corneal fibroblast cell line. The analytical results indicated that the GBH-2 hydrogel exhibited the lowest loss rate of contact angle (28%) and similar rheological performance as compared with other investigated hydrogels and the control group. Printability results also showed that the average wire diameter of the GBH-2 bioink (0.84 ± 0.02 mm (*** p < 0.001)) post-printing was similar to that of the control group (0.79 ± 0.05 mm). Moreover, a cell scaffold could be fabricated from the GBH-2 bioink and retained its shape integrity for 24 h post-printing. For bioprinting evaluation, it demonstrated that the GBH-2 bioink possessed well viability (>70%) of the human corneal fibroblast cell after seven days of printing under an ideal printing parameter combination (0.4 mm of inner diameter needle, 0.8 bar of printing pressure, and 25 °C of printing temperature). Therefore, the present study suggests that the GBH-2 hydrogel could be developed as a potential cell-laden bioink to print a cell scaffold with biocompatibility and structural integrity for soft tissues such as skin, cornea, nerve, and blood vessel regeneration applications.

Advanced optical assessment and modeling of extrusion bioprinting

“…In other research, the deflection angle was measured 20 s post-deposition, though deformation continued at a slower pace, as discerned from a 24-h creep analysis of the hydrogels 22 . Elsewhere, the filament was captured immediately post-deposition in a FFT, to prevent undesired material spreading 14 . Given the diverse methods of conducting similar experiments, it is essential to emphasize the unification of measurement procedures to enhance comparability, especially when incorporating time dependency into such evaluations 23 .…”

“…The Filament Fusion Test (FFT) evaluates the thickness of a printed strand by employing a narrowing pattern of printed lines. As the spacing between the lines decreases, it eventually leads to the fusion of two neighboring strands [11][12][13][14] . Another version involves the printing of a rectangular pore to determine material spreading, comparing the theoretical to the actual perimeter area within the pore.…”

An Innovative Biofunctional Composite Hydrogel with Enhanced Printability, Rheological Properties, and Structural Integrity for Cell Scaffold Applications

“…Alginate and gelatin composite hydrogels are the most widely used composites for fabricating tissues and organs for bone engineering; they have cell-binding motifs to facilitate cell adhesion, excellent structural integrity, and extrusion printability [14,15]. Due to the latter, exploring the printability of irregularly shaped hydrogels is necessary to improve the rheological properties of alginate-gelatin hydrogels and ensure good printability, shape fidelity, and cell viability [16,17]. When designing biopolymer inks, one of the most important considerations is the rheology characterization.…”

3D-Bioprinted Biomimetic Multilayer Implants Comprising Microfragmented Adipose Extracellular Matrix and Cells Improve Wound Healing in a Murine Model of Full-Thickness Skin Defects

“…The goal of bioprinting technology for tissue engineering is to improve the transplantation success rate, accelerate wound repair, promote vascularization, and reduce pathogen transfer and immune rejection . Fibrin, alginate, chitosan, polycaprolactone, gelatin, and the derivative gelatin methacrylate have been extensively explored and used in 3D bioprinting to construct skin scaffolds. − …”