Pectin-based bioinks for 3D models of neural tissue produced by a pH-controlled kinetics

Abstract

Introduction: In the view of 3D-bioprinting with cell models representative of neural cells, we produced inks to mimic the basic viscoelastic properties of brain tissue. Moving from the concept that rheology provides useful information to predict ink printability, this study improves and expands the potential of the previously published 3D-reactive printing approach by introducing pH as a key parameter to be controlled, together with printing time.Methods: The viscoelastic properties, printability, and microstructure of pectin gels crosslinked with CaCO3 were investigated and their composition was optimized (i.e., by including cell culture medium, HEPES buffer, and collagen). Different cell models representative of the major brain cell populations (i.e., neurons, astrocytes, microglial cells, and oligodendrocytes) were considered.Results and Discussion: The outcomes of this study propose a highly controllable method to optimize the printability of internally crosslinked polysaccharides, without the need for additives or post-printing treatments. By introducing pH as a further parameter to be controlled, it is possible to have multiple (pH-dependent) crosslinking kinetics, without varying hydrogel composition. In addition, the results indicate that not only cells survive and proliferate following 3D-bioprinting, but they can also interact and reorganize hydrogel microstructure. Taken together, the results suggest that pectin-based hydrogels could be successfully applied for neural cell culture.

A novel on-a-chip system with a 3D-bioinspired gut mucus suitable to investigate bacterial endotoxins dynamics

“…Considering the perspective of using the MI-device in culture condition with the presence of eukaryotic cells, the I-Bac3Gels were produced in DMEM and the hydrogel formation achieved by crosslinking alginate with insoluble calcium salts and an acidifying agent to reach homogeneous properties [ 75 , 77 , [95] , [96] , [97] ]. The formulation here proposed showed an elastic -like predominant behaviour ( G’ > G″ ), expressing viscoelastic moduli in the physiological range of reference (2–200 Pa) ( Fig.…”

Global hotspots and emerging trends in 3D bioprinting research

“…Besides, it is worth noting that gelatin is mostly used in combination with other materials in bioinks, and its main function is to maintain the shape of the printing scaffold before ink crosslinking. After 2018, more materials have been discovered to be suitable for use as bio-inks., including chitosan ( Kołodziejska et al 2021 ; Xu J. et al 2022 ; Lazaridou et al 2022 ), gellan gum ( Cernencu and Ioniță, 2023 ), hydroxyapatite ( Heid and Boccaccini, 2020 ), pectin ( Mahendiran et al 2021 ; Merli et al 2022 ), cellulose ( Ahlfeld et al 2020 ; Zennifer et al 2021 ) and polysaccharides ( Naranda et al 2021 ; Teixeira et al 2022 ). Meanwhile, we also noticed that dECM, GelMA, and alginate have received more attention recently.…”