# Universal Solvent Escape Strategies for Efficient Curing of Hydrogen‐Bond‐Rich 3D Printing Inks

## TL;DR

A new 3D printing method enables fast and precise fabrication of scaffolds using hydrogen-bonded polymers, with applications in tissue engineering and drug delivery.

## Contribution

A universal solvent escape strategy combining solvent replacement, nanoparticle-induced turbulence, and optimized printing paths for efficient curing of hydrogen-bonded inks.

## Key findings

- The integrated strategy enabled rapid (<3 min) and structurally precise scaffold fabrication using polymers like chitosan, collagen, and cellulose.
- Scaffolds showed pH-responsive drug delivery and enhanced osteogenic and angiogenic performance via calcium signaling and HIF-1α activation.
- Molecular dynamics and finite element analysis provided insights into solvent removal and curing behavior.

## Abstract

Hydrogen‐bonded polymers have attracted significant interest in biomedical applications due to their excellent biocompatibility, adjustable mechanical properties, and responsiveness to environmental cues. However, these materials face substantial challenges in direct ink writing, primarily arising from persistent solvent entrapment within dense hydrogen‐bonded networks. This trapped solvent severely impairs the printability, drying efficiency, and structural fidelity of scaffolds. To overcome these limitations, this study introduced innovative universal solvent escape strategies integrating three key mechanisms: first, solvent replacement disrupted existing hydrogen‐bonded polymer complexes; second, nanoparticle‐induced microturbulence significantly enhanced solvent evaporation rates; third, computationally optimized printing paths facilitated efficient solvent evacuation. Molecular dynamics simulations provided quantitative insights into how various ways can effectively destroy hydrogen bond solvent networks, allowing rapid solvent removal. Finite element analysis accurately visualized the curing behavior to maximize solvent extraction. This integrated strategy enabled exceptionally rapid (< 3 min) and structurally precise scaffold fabrication across diverse hydrogen‐bonded polymers, including chitosan, collagen, and cellulose. Furthermore, these scaffolds exhibited multifunctional capabilities, utilizing hydrogen‐bonding networks for both structural integrity and pH‐responsive drug delivery. Functional scaffold confirmed significantly improved osteogenic and angiogenic performance via enhanced calcium signaling and activation of HIF‐1α pathways, thereby advancing the fields of tissue engineering and controlled therapeutic delivery.

This study developed a new 3D printing method for hydrogen‐bonded polymers by combining solvent replacement, nanoparticles, and optimized printing paths. This allows fast, precise scaffold fabrication. The scaffolds can be easily customized and release therapeutic agents slowly through protonation, enabling personalized bone, blood vessel, and nerve repair for advanced tissue engineering applications.