Electrically stimulated 3D bioprinting of gelatin-polypyrrole hydrogel with dynamic semi-IPN network induces osteogenesis via collective signaling and immunopolarization

Sayan Deb Dutta; Keya Ganguly; Aayushi Randhawa; Tejal V Patil; Dinesh K Patel; Ki-Taek Lim

doi:10.1016/j.biomaterials.2023.121999

Electrically stimulated 3D bioprinting of gelatin-polypyrrole hydrogel with dynamic semi-IPN network induces osteogenesis via collective signaling and immunopolarization

Biomaterials. 2023 Mar:294:121999. doi: 10.1016/j.biomaterials.2023.121999. Epub 2023 Jan 14.

Authors

Sayan Deb Dutta¹, Keya Ganguly¹, Aayushi Randhawa², Tejal V Patil², Dinesh K Patel³, Ki-Taek Lim⁴

Affiliations

¹ Department of Biosystems Engineering, Kangwon National University, Chuncheon, 24341, Republic of Korea.
² Department of Biosystems Engineering, Kangwon National University, Chuncheon, 24341, Republic of Korea; Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon, 24341, Republic of Korea.
³ Institute of Forest Sciences, Kangwon National University, Chuncheon, 24341, Republic of Korea.
⁴ Department of Biosystems Engineering, Kangwon National University, Chuncheon, 24341, Republic of Korea; Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon, 24341, Republic of Korea; Institute of Forest Sciences, Kangwon National University, Chuncheon, 24341, Republic of Korea; Biomechagen Co., Ltd., Chuncheon, 24341, Republic of Korea. Electronic address: ktlim@kangwon.ac.kr.

PMID: 36669301
DOI: 10.1016/j.biomaterials.2023.121999

Abstract

In recent years, three-dimensional (3D) bioprinting of conductive hydrogels has made significant progress in the fabrication of high-resolution biomimetic structures with gradual complexity. However, the lack of an effective cross-linking strategy, ideal shear-thinning, appropriate yield strength, and higher print fidelity with excellent biofunctionality remains a challenge for developing cell-laden constructs, hindering the progress of extrusion-based 3D printing of conductive polymers. In this study, a highly stable and conductive bioink was developed based on polypyrrole-grafted gelatin methacryloyl (GelMA-PPy) with a triple cross-linking (thermo-photo-ionically) strategy for direct ink writing-based 3D printing applications. The triple-cross-linked hydrogel with dynamic semi-inner penetrating polymer network (semi-IPN) displayed excellent shear-thinning properties, with improved shape fidelity and structural stability during 3D printing. The as-fabricated hydrogel ink also exhibited "plug-like non-Newtonian" flow behavior with minimal disturbance. The bioprinted GelMA-PPy-Fe hydrogel showed higher cytocompatibility (93%) of human bone mesenchymal stem cells (hBMSCs) under microcurrent stimulation (250 mV/20 min/day). Moreover, the self-supporting and tunable mechanical properties of the GelMA-PPy bioink allowed 3D printing of high-resolution biological architectures. As a proof of concept, we printed a full-thickness rat bone model to demonstrate the structural stability. Transcriptomic analysis revealed that the 3D bioprinted hBMSCs highly expressed gene hallmarks for NOTCH/mitogen-activated protein kinase (MAPK)/SMAD signaling while down-regulating the Wnt/β-Catenin and epigenetic signaling pathways during osteogenic differentiation for up to 7 days. These results suggest that the developed GelMA-PPy bioink is highly stable and non-toxic to hBMSCs and can serve as a promising platform for bone tissue engineering applications.

Keywords: 3D bioprinting; Conductive hydrogels; Direct ink writing; Ex-vivo printing; Non-Newtonian flow; Osteogenesis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Bioprinting* / methods
Gelatin / chemistry
Humans
Hydrogels* / chemistry
Osteogenesis
Polymers
Printing, Three-Dimensional
Pyrroles
Rats
Tissue Engineering / methods
Tissue Scaffolds / chemistry

Substances

Hydrogels
polypyrrole
Polymers
Pyrroles
Gelatin