Design and Synthesis of Chitosan-Gelatin Hybrid Hydrogels for 3D Printable in vitro Models.

Sofia Magli,Elisa Masseroni,Francesco Nicotra,Giulia Risi,Sabrina Bertini,Elisa Ballarini,Giulia Beatrice Rossi,Cesare Cosentino,Luca Crippa,Guido Cavaletti,Laura Piazza,Laura Russo

doi:10.3389/fchem.2020.00524

Abstract

The development of 3D printable hydrogels based on the crosslinking between chitosan and gelatin is proposed. Chitosan and gelatin were both functionalized with methyl furan groups. Chemical modification was performed by reductive amination with methyl furfural involving the lysine residues of gelatin and the amino groups of chitosan to generate hydrogels with tailored properties. The methyl furan residues present in both polymers were exploited for efficient crosslinking via Diels-Alder ligation with PEG-Star-maleimide under cell-compatible conditions. The obtained chitosan-gelatin hybrid was employed to formulate hydrogels and 3D printable biopolymers and its processability and biocompatibility were preliminarily investigated.

Highlights

This strategy requires the introduction in the biopolymer chains of functional groups able to react with sufficiently fast kinetics in mild and biocompatible conditions and without the formation of toxic side products—in other words, a “click reaction” (Nimmo and Shoichet, 2011; Azagarsamy and Anseth, 2013; Tam et al, 2017)
Gelatin (GE) and chitosan (CH) were chosen as commercially available starting materials with biocompatible properties. Both GE and CH starting polymers were functionalized by reductive amination with 5-methyl furfural, in order to obtain the methylfuran derivatives GE-MF and CH-MF (Scheme 2)
CH-MF and GE-MF were characterized by chemical-physical methods to determine the reproducibility of the reaction and the degree of functionalization

Summary

Introduction

This strategy requires the introduction in the biopolymer chains of functional groups able to react with sufficiently fast kinetics in mild and biocompatible conditions and without the formation of toxic side products—in other words, a “click reaction” (Nimmo and Shoichet, 2011; Azagarsamy and Anseth, 2013; Tam et al, 2017). In order to fulfill this objective, we have investigated a strategy to functionalize gelatin and chitosan, selected as biopolymers, in order to obtain a final construct with both polysaccharide and protein properties.

Results

Conclusion