Figure 43 Schematic of the HGSM synthesis (left) and HGGelMA
construction (right).[151]
The water-soluble ultraviolet PI Irgacure 2959 has been widely used in
cell encapsulation and tissue
engineering,[152-154] however, there are
significant limitations to its application. Firstly, UV light has been
known to be harmful for delivered cells and host tissues, secondly, its
solubility in water is relatively poor.[152,
155-156] Thus, the limitations of UV sources can be avoided by
employing PI which could match to visible light. Lithium acylphosphinate
salt (LAP) as a visible light PI possesses fine water solubility and
allows cell encapsulation at lower PI concentrations, enabling efficient
photopolymerization compared to Irgacure 2959. Monteiro et
al.[157] prepared the gelatin methacryloyl (GelMA)
hydrogels encapsulating odontoblast-like cells by using dental curing
devices (DL) with emission wavelength in visible light range, as shown
in Figure 44. The results show that short-time exposure to DL did not
significantly affect cell survival, simultaneously, preparation of GelMA
hydrogels by DL source is faster than UV source, and showed higher
cellular activity with larger pore sizes.