The Horizon of the Emulsion Particulate Strategy: Engineering Hollow Particles for Biomedical Applications

Abstract

With their hierarchical structures and the substantial surface areas, hollow particles have gained immense research interest in biomedical applications. For scalable fabrications, emulsion-based approaches have emerged as facile and versatile strategies. Here, the recent achievements in this field are unfolded via an "emulsion particulate strategy," which addresses the inherent relationship between the process control and the bioactive structures. As such, the interior architectures are manipulated by harnessing the intermediate state during the emulsion revolution (intrinsic strategy), whereas the external structures are dictated by tailoring the building blocks and solidification procedures of the Pickering emulsion (extrinsic strategy). Through integration of the intrinsic and extrinsic emulsion particulate strategy, multifunctional hollow particles demonstrate marked momentum for label-free multiplex detections, stimuli-responsive therapies, and stem cell therapies.

Fundamentals and Design‐Led Synthesis of Emulsion‐Templated Porous Materials for Environmental Applications

“…In addition to the environmental applications described above, emulsion‐templated porous materials have also been widely used in other applications such as heterogeneous catalysis, [ 132 , 152 , 203 , 211 , 220 , 226 , 249 ] biomedical applications, [ 26 , 50 , 161 , 170 ] energy storage, [ 234 , 236 , 241 , 251 , 258 ] and chromatography, [ 111 , 123 ] to name a few. All these applications have explored the highly interconnected hierarchical porosity, chemical functionality and desired physical properties presented by emulsion‐templated porous materials.…”

“…This concept of stabilizing interfaces with particles of different shapes and sizes is known as the “Pickering effect” or “Pickering stabilization”, [ 47 ] which has also been used to stabilize O/W, water‐in‐oil (W/O), and non‐aqueous emulsions. [ 48 , 49 , 50 , 51 ] Different types of particles including metal–organic framework (MOF) nanoparticles (NPs) have been used as stabilizers for Pickering emulsions. [ 51 ] For instance, the W/W emulsions have been stabilized with nanoplates and nanorods in the form of cellulose nanocrystals.…”

Antibacterial, conductive, and osteocompatible polyorganophosphazene microscaffolds for the repair of infectious calvarial defect

“…In the field of tissue engineering, microsphere-type microscaffolds are highlighted due to the flexibility in their compositions and functional designs and as units to construct 3D structures with desired spacial speciality, as well as, their injectability to fill irregular defects at minimal invasion. 36,37 In this study, multipurpose biodegradable microspheres were developed in order to regenerate bone defects in the conditions of the severely infected cases. Apart from antibacterial activity, other functions like antioxidant activity and osteoinductivity are also crucial in determining the efficiency of bone formation.…”

Nanomotor‐Derived Porous Biomedical Particles from Droplet Microfluidics

“…[ 10 , 11 ] As an alternative, emulsion‐based technique is a popular method for porous particle generation, specifically including phase inversion, phase ripening, and phase separation. [ 8 , 12 ] Compared with the template method, this technique does not require removing process, and thus there is no extra etchants or pore‐forming agents needed, which indicates the emulsion‐based procedure is biologically safer to some extent. [ 13 , 14 ] However, the generation devices used in this method always need elaborate design that is not easy‐operating, and the diffusion of organic solvents during the process can also affect the biocompatibility of the generated particles, which might hamper their further applications in biomedicine.…”