Visible light-induced crosslinking of unmodified gelatin with PEGDA for DLP-3D printable hydrogels

Electroconductive Photo-Curable PEGDA-Gelatin/PEDOT:PSS Hydrogels for Prospective Cardiac Tissue Engineering Application

“…As shown in Figure 1A, after an initial induction time with unchanged G' (i.e., the irradiation time required to induce cross-linking), G' increased as a function of irradiation time, finally reaching a plateau value, suggesting successful photopolymerization for all tested formulations. Therefore, the role of gelatin as a co-initiator in the radical photo-initiating system involving RF as type II photosensitizer was confirmed, in agreement with previous studies (Cosola et al, 2019;Zanon et al, 2021).…”

“…Particularly, the two peaks at 1,644 and 1,540 cm −1 were attributed to the characteristic amide I (C=O stretching mode) and amide II (N-H bending mode) bands of gelatin, respectively. These results suggested the covalent bonding of gelatin within the hydrogel network as previously reported (Cosola et al, 2019;Zanon et al, 2021). Furthermore, all tested formulations showed the presence of the typical absorption peak of carbonyl groups of PEGDA at 1724 cm −1 (C=O stretching mode).…”

“…Previous literature reported that, after taking part in the photoinduced generation of radicals, gelatin remains covalently bonded to the hydrogel network (Cosola et al, 2019;Zanon et al, 2021). In this work, initially the chemical cross-linking of gelatin was qualitatively evaluated by means of infrared spectroscopy.…”

“…In the biomedical field, several photo-crosslinkable hydrogels with tunable mechanical and chemical properties have been reported (Choi et al, 2019). Recently, an innovative photocurable hybrid natural-synthetic hydrogel for biomedical applications has been proposed by Sangermano and coworkers (Cosola et al, 2019;Zanon et al, 2021). Instead of traditional aliphatic or aromatic amines, unmodified gelatin was used as the co-initiator in a Norrish type II photoinitiating system involving PEGDA as the crosslinker and camphorquinone as the photoinitiator.…”

Effects of the number and position of methoxy substituents on triphenylamine-based chalcone visible-light-absorbing photoinitiators

“…Because the photoinitiator must strongly absorb light in the visible range, various free radical photoinitiators have been recently developed, such as those based on the oxime ester, [14][15][16][17][18] phosphine oxide, 19 and acetophenone 20 for type I photoinitiation systems and on benzophenone, 21,22 thioxanthone, [23][24][25] camphorquinone, 26 hexaaryl biimidazole 27 and flavonol 28 for type II photoinitiation systems. A type II photoinitiator, chalcone, is currently considered to be a promising candidate because (1) the chalcone moiety can be easily prepared in high yield through a Claisen-Schmidt reaction, (2) chalcone's derivatives can be easily designed and modified, and (3) chalcone is present in numerous plants and offers biocompatibility.…”