Facile fabrication of near‐infrared light‐responsive shape memory nanocomposite scaffolds with hierarchical porous structures

Abstract

In this work, the near‐infrared (NIR) light‐responsive shape memory scaffolds with hierarchical porous structures are designed and facilely formed by freeze drying of 3D printed viscous gel‐like pickering emulsions, which are stabilized by hydrophobically modified graphene oxide (g‐GO) and silica nanoparticles, and contain thermo‐responsive poly(d, l‐lactic acid‐co‐trimethylene carbonate) (PLMC) in the oil phase. The prepared scaffolds display an interconnected filament structure with hierarchical pores and high porosity. The incorporation of g‐GO nanoparticles into PLMC matrix prompts that the scaffold shape memory can be triggered by NIR light with fast shape recovery. Moreover, the in vitro mineralization experiment shows that the scaffolds have biological activity, and the drug release study demonstrates that the scaffolds can be used as drug carriers with efficient drug release capacity. Furthermore, cell culture assays based on mouse bone mesenchymal stem cells exhibit that the scaffolds own good cytocompatibility. Therefore, the facile preparation and remote activation of the shape memory nanocomposite scaffolds with hierarchical porous structure and multifunctionality represents a highly attractive candidate as minimally invasive implantation scaffolds for bone tissue engineering applications.

Glass, Ceramic, Polymeric, and Composite Scaffolds with Multiscale Porosity for Bone Tissue Engineering

“…In this method, 3D printing makes the macropores and the emulsion droplets and the pore throats form the micropores. [219][220][221][222][223][224] For example, nanoHA/PCL composite scaffolds have been prepared by 3D printing of HIPEs. To achieve this, a dichloromethane solution containing PCL with dispersed HA and silica nanoparticles was transformed into a water-in-oil HIPE by slowly adding water.…”

“…Multiple steps involved, difficult to achieve full interconnectivity between micropores [214][215][216][217][218] 3D printing with emulsion templating Polymers, composites Control over scaffold shape, high reproducibility Multiple steps involved; necessary to find the correct surfactants to stabilize emulsions for each specific system [219][220][221][222][223][224] Gas foaming with emulsion templating…”

“…[ 220 ] In another study, poly( d , l ‐lactide ‐co ‐trimethylene carbonate) scaffolds with macropores of diameter ≈1 mm and micropores of diameter <10 μm were prepared by a similar approach using partially hydrophobic silica as thickener and stabilizer along with hydrophobically modified graphene oxide nanoparticles as another stabilizer (Figure 5 M,N). [ 223 ] In a study, a combination of gas foaming with emulsion templating resulted in PCL/poly(urethane urea) (PUU) scaffolds with dual porosity. [ 225 ] Here, a water‐in‐oil emulsion was prepared by using a continuous organic phase composed of an oligomeric polyol, toluene and a diisocyanate and the droplet phase composed of NaCl and water.…”

“…M,N) 3D printing and emulsion templating method. Adapted with permission [223]. Copyright 2016, John Wiley and Sons.…”

Light and Shape‐Memory Polymers: Characterization, Preparation, Stimulation, and Application

“…In this section, photothermal fillers at micro-/nanoscale which can present wide spectrum absorption are introduced and used to create SMP composites (SMPCs). [33][34][35][36][37][38][39][40][41] The approaches to enhance filler dispersion in SMPCs are discussed, which ensure both good thermal conductivity and mechanical property reinforcement. More importantly, many organic functional groups and inorganic fillers present selective absorption toward light with unique wavelengths including UV light, visible light, and so on.…”