One-step 3D printing of polyurethane structures with tailored intrinsic porosity for wound dressing applications using immersion precipitation 3D printing

Purpose Porous structures are crucial for wound dressings, but conventional 3D printing techniques often struggle to produce them effectively. This study aims to develop a one-step 3D printing method to fabricate polyurethane wound dressings with tunable pore architectures, addressing the limitations of traditional approaches. Surface roughness and porosity can be controlled in the present method, leading to a potential influence on cell behavior that promotes wound healing. Design/methodology/approach A novel immersion precipitation 3D printing (ip-3D printing) technique was used, leveraging solvent/non-solvent exchange to control porosity. Four solvent/non-solvent systems were tested to evaluate their effects on pore morphology, printability and biological performance. The resulting structures were characterized using scanning electron microscopy, mechanical testing, water uptake analysis and water vapor transmission rate (WVTR) measurements. In vitro biocompatibility was assessed via live/dead assays, MTS assays and cellular morphology analysis. Findings Non-solvent type and printing conditions significantly influenced pore structure, with exchange rate mechanisms (nucleation and growth, or spinodal decomposition) dictating pore morphology (dense, foam-like or fingerlike). WVTR measurements confirmed microstructure-dependent permeability. In vitro studies demonstrated excellent biocompatibility, with cellular behavior strongly linked to pore architecture. Originality This work introduces the application of one-step ip-3D printing method for foam-like polyurethane wound dressings for the first time, enabling precise control over pore size and surface morphology without post-processing. By linking solvent/non-solvent dynamics to cellular response, it offers a scalable platform for designing customized wound dressings with enhanced performance.