Tunable construction of multi-shelled hollow carbonate nanospheres and their potential applications

Abstract

The development of multi-shelled hollow carbonate nanospheres (MHCN) for biomedical applications is challenging, and has not been reported. In this study, a facile approach is firstly reported to synthesize hierarchically porous MHCN with controllable shell numbers using a novel strategy called layer-by-layer thermal decomposition of organic acid salts and templates. The choice of organic acid salts as the reactants is innovative and crucial. The shell numbers of porous MHCN can be easily controlled and tuned through adjusting the adsorption temperature of organic acid salts and/or the adsorption ability of the template. The synthetic method can not only open a window to prepare the multi-shelled carbonates but also provide a new strategy to synthesise other multi-shelled inorganic salts. Notably, the hierarchically porous multi-shelled hollow structures empower the carbonates with not only a large specific surface area but also good porosity and permeability, showing great potential for future applications. Herein, our in vitro/vivo evaluations show that CaCO3 MHCN possess a high drug loading capacity and a sustained-release drug profile. It is highly expected that this novel synthetic strategy for MHCN and novel MHCN platform have the potential for biomedical applications in the near future.

Sequential Templating Approach: A Groundbreaking Strategy to Create Hollow Multishelled Structures

“…Owing to their unique physical/chemical properties, HoMSs have been widely functionalized and applied to broad applications, such as lithium ion batteries, solar cells, photocatalysis, sensors, supercapacitors, and drug delivery . Well understanding of geometric effects on properties may promote the rapid development of HoMSs in practical applications.…”

“…Compared with mesoporous structures, HoMSs have more internal cavities that are arranged in order so that sequential catalysis or sequential release can be realized. Therefore, HoMSs are expected to have better performances over their single‐ or double‐shelled counterparts and other ordinary porous structures or nanostructures for applications such as electrochemical energy storage, solar energy conversion, electromagnetic wave absorption, catalysis, and drug delivery …”

Sequential drug release via chemical diffusion and physical barriers enabled by hollow multishelled structures

“…11 ). By combination with the physical barriers introduced by the multi-shell configuration, the release period is prolonged 19 , 32 , 35 – 37 . It is worth noting that the concentration plateau for 3s-TiO 2 –HoMS is lower than that of other TiO 2 systems with the same amount of drug added, which means that the drug molecules are more difficult to release from the triple shells.…”

Small Structures Bring Big Things: Performance Control of Hollow Multishelled Structures

“…The elemental compositions of the HoMSs can be directly determined by the adopted precursors during the synthetic process. Up to now, diverse HoMSs including metal oxides, [ 54 ] sulfides, [ 43 ] phosphides, [ 55 ] carbides, [ 56 ] carbonates, [ 57 ] perovskite, [ 58 ] carbon materials, [ 59 ] organic polymers, [ 60 ] etc. have been successfully fabricated.…”