Browsing by Subject "4D printing"

4D printing is becoming increasingly investigated as it is emerging as a pioneering method for biofabrication. By implementing programmable shape changing thermoresponsive hydrogels in bioink formulations, a 4D response can be achieved, which can be manipulated to print artificial organs and tissues. The limited selection of biocompatible thermoresponsive hydrogels, accompanied by the mechanical weakness of hydrogels have restricted the mainstream application of this technology in the field of bioprinting. The most commonly studied thermoresponsive polymer is poly(N-isopropylacrylamide), but it is understood that the monomer N-isopropylacrylamide exhibits cytotoxicity at low concentrations. The primary goal of this study is to investigate poly(2-substituted-2-oxazoline) macromonomers as potential alternatives to poly(N-isopropylacrylamide), and the secondary goal is to investigate microgels as an additive in crosslinked networks to enhance hydrogel mechanical strength. The results in this work indicate that poly(2-n-propyl-2-oxazoline-co-2-ethyl-2-oxazoline) is a promising candidate for 4D printing, because it’s LCST can be fine-tuned by altering the monomer ratio. However, it still requires further investigation as it requires an acrylamide comonomer to crosslink, and it also has compatibility issues with commercial printing additives like Pluronic F127. The addition of 2 wt.% microgel also showed promise as it enhanced the hydrogels mechanical strength over threefold.