•The dual-responsive bioscaffold can realize the minimally invasive implantation and precise navigation.•The hybrid printing ink exhibits excellent shape memory and hydrophilic properties.•The ...synergistic application of NIR and SMF effectively fosters vascularized bone regeneration.
Currently, treating irregular bone defects with a critical size is still challenging as material implantation in the complex defects with irregular shapes, effective osteogenesis and sufficient vascularization cannot be easily achieved simultaneously via a simple strategy. Herein, a dual-responsive bone tissue engineering scaffold is developed using a 4D printing strategy by intergrating a single type of multifunctional magnetic nanoparticles, Fe3O4@SiO2, with printing inks made of bioceramics and biopolymers. Minimally invasive implantation, fluent navigation of scaffolds as well as the precise boundary matching between scaffolds and the irregular defects are achieved through near-infrared (NIR) irradiation-based temperature responsive shape recovery and static magnetic field (SMF) stimulation. Moreover, improved bone regeneration in critical-sized bone defects is successfully achieved through the activation of PI3K/AKT pathway which significantly promotes osteogenic differentiation and vascularization. Besides, NIR-based photothermal stimulation upregulates the expression of heat shock protein (HSP90) and further promotes the osteogenesis and vascularization. The in vivo study also confirms that our scaffold can precisely fit the bone defect, and induce satisfactory osteogenesis and angiogenesis. This work provides a facile strategy to simultaneously-realize easy scaffold implantation in irregular bone defects and improves osteogenesis and angiogenesis by integrating a single type of multifunctional nanoparticles with scaffold matrices.
We designed a UV-crosslinked network to prepared 4D printed smart structures through UV-assisted DIW printing. 4D printed semi-IPN were obtained through a two-stage UV-thermal curing process, ...resulted in an increase in the glass transition temperature to a maximum of 187.4 °C. The highest storage modulus (5229MPa) and the lowest shrinkage rate (0.21%) were achieved of 4D printed polymer. 4D printed composite structure realizes in-situ self-blocking second-stage curing, deformation process after curing.
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•Designed a UV-crosslinked network for 4D printed smart structures.•High modulus and low shrinkage of printed materials through a two-step curing design.•Composite sandwich structure with electrical-driven shape memory performance.
In recent years, the field of shape memory materials with active deformation capabilities has experienced rapid development. However, bismaleimide, as a widely used structural material in the aerospace industry, has been neglected in the field of shape memory. This work designed a UV-crosslinked network with 1-vinyl-2-pyrrolidone monomer, and prepared 4D printed smart structures based on shape memory bismaleimide resin through UV-assisted DIW printing. 4D printed semi-interpenetrating network polymer materials were obtained through a two-stage UV-thermal curing process, resulted in an increase in the material's glass transition temperature to a maximum of 187.4 °C. The storage modulus was improved to 5229 MPa. More important, we achieved a lowest shrinkage rate (0.21 %) of 4D printed polymer. The composite sandwich structure with electrical-driven shape memory performance was printed by double-sided printing of bismaleimide resin on conductive carbon fabric. 4D printed composite structure realizes in-situ self-blocking secondary curing, deformation process after curing. This significant progress provides a promising prospect for remote controllable and precise driving in the aerospace field.
