Adjusting the accuracy of PEGDA-GelMA vascular network by dark pigments via digital light processing printing

Abstract

Vascularization is one of the most important factors greatly influencing scaffold regeneration. In this study, a precise network of hollow vessels was printed by digital light processing (DLP) with poly(ethylene glycol) diacrylate (PEGDA)/gelatin-methacryloyl (GelMA), and dark pigmentation absorbers were added to ensure printing accuracy. First, the compound bio-inks of the PEGDA-GelMA hydrogel were prepared for direct vascular printing, and a high-precision DLP system was established. Second, the printing effects of three dark absorbers, namely, nigrosin, brilliant black, and brilliant blue, on the x-, y-, and z-axes were studied. By printing models with different densities, it was determined that 0.2% nigrosin, 0.1% brilliant black, and 0.3% brilliant blue had better effects on the x- and y-axes accuracy, and the absorbance of the absorbers played a decisive role in adjusting the accuracy. Additionally, to solve the problem of uneven curing on the upper and lower surfaces caused by the addition of an absorber with high absorbance, a model of the difference in curing width between the upper and lower surfaces of a unit-layer slice based on high-absorbance absorbers was established, and the reference value for the slice thickness was calculated. Third, the biological and mechanical properties of the bio-inks were verified with scanning electron microscopy and Fourier transform infrared, and by tensile, swelling, degradation, and cytotoxicity tests on different concentrations of PEGDA-GelMA hydrogel and absorbers. The results showed that 30% PEGDA-7% GelMA/0.1% brilliant black was the optimal preparation to print a hollow vascular network. The error of the printing tube wall and cavity was between 1% and 3%, which demonstrates the high precision of the method. Human umbilical vein endothelial cells were planted in the lumen, and the survival rate achieved 107% on the seventh day, demonstrating the good biocompatibility of the composite hydrogel.

PBP‐based bioprinting of hydrogels for biomedical applications

“…101,102 The addition of GelMA can improve the elastic properties of PEGDA hydrogel scaffolds and print vascular network structures with good performance. 65 The addition of PAs also improves printing accuracy. HUVECs are implanted into the lumen.…”

“…In particular, the 3D vascular network is more conducive to nutrient exchange and cellular perfusion 101,102 . The addition of GelMA can improve the elastic properties of PEGDA hydrogel scaffolds and print vascular network structures with good performance 65 . The addition of PAs also improves printing accuracy.…”

Three-Dimensional (3D) Printing in Cancer Therapy and Diagnostics: Current Status and Future Perspectives

“…In a study, PEGDA and silk methacrylate were used to develop photo-cross-linkable bio-ink together with chondrocytes for the biofabrication of 3D bioprinted cartilage constructs, which increased the expression of aggrecan and collagen type II and suggested that silk methacrylate (SilMA)-polyethylene glycol diacrylate (PEGDA) bio-ink could be a potential candidate for bioprinting chondrocytes to develop cartilage tissue repair and regeneration [96]. In a study, it was reported that composite hydrogel containing 30% PEGDA-7% GelMA/0.1% brilliant black was used to print a hollow vascular network, and, after printing human umbilical vein endothelial cells, showed an increased survival rate one week post-printing and exhibited effective biocompatibility of the composite hydrogel [97]. In another study, PEG-clay nanocomposite cross-linking hydrogel has been developed to fabricate the 3D printing of osteoblast cells.…”

Additive Manufacturing and Physicomechanical Characteristics of PEGDA Hydrogels: Recent Advances and Perspective for Tissue Engineering

“…The hydrogels have also be used in various other applications, such as in the fabrication of micro-and nano-devic [47][48][49]. Moving away from molding and bulk cross-linking processes, 3D printing using s reolithography (SLA) and digital image processing (DLP) among other advanced printi techniques offer a faster and more dependable manufacturing approach for creating com plex scaffold shapes with reliable mechanical properties [50][51][52][53]. The use of 3D print PEGDA hydrogels has been studied extensively for developing skeletal muscle microt sues and contractile cardiac tissue as the demand for PEGDA hydrogels continues to gro (Figure 2).…”

“…Previo papers mainly focused on the synthesis of the PEGDA hydrogels and material design an fabrication of bioactive hydrogels and their cell viability and interactions with the EC and neglected the importance of studying the fabrication processes and how different p rameters can influence the physicochemical and mechanical properties of the 3D PEGD hydrogels [54,55]. The impact of layer-by-layer (LbL) fabrication on number of intrin properties of photo-cross-linked 3D printed PEGDA hydrogels including their chemic Moving away from molding and bulk cross-linking processes, 3D printing using stereolithography (SLA) and digital image processing (DLP) among other advanced printing techniques offer a faster and more dependable manufacturing approach for creating complex scaffold shapes with reliable mechanical properties [50][51][52][53]. The use of 3D printed PEGDA hydrogels has been studied extensively for developing skeletal muscle microtissues and contractile cardiac tissue as the demand for PEGDA hydrogels continues to grow (Figure 2).…”