Nonaqueous Synthesis of Macroporous Nanocomposites Using High Internal Phase Emulsion Stabilized by Nanohydroxyapatite

Abstract

Nonaqueous high internal phase emulsions (HIPEs) stabilized by nanohydroxyapatite (NHA)/surfactant hybrids are used as template to prepare interconnected porous monoliths. The use of a sustainable deep eutectic solvent (DES) comprised of urea and choline chloride (UChCl), as the internal phase, enables an efficient interaction of NHA/surfactant at the HIPE interface, which in turn allows for a bottom‐up approach to selective interfacial functionalization of poly(HIPE's) voids surface after polymerization of methyl methacrylate continuous phase. UChCl DES is a suitable internal phase for HIPE polymerization thanks to its polarity and viscosity that provides further stabilization of the emulsion precursor. This simple synthetic method produces well‐defined functional poly(methyl methacrylate) (pMMA) scaffolds with tunable mechanical properties and exposed NHA at the inner surface. Based upon a preliminary biocompatibility in vivo test, poly(HIPEs) show enhanced biocompatibility in comparison with sterile gauze. Interestingly, pMMA NHA nanocomposite scaffold remains in the tissue after 90 d allowing little ingrowth of cells while causing a normal foreign‐body reaction in the rats' muscle tissue. Interfacial functionalization of well‐defined interconnected porous monoliths with nanomaterials via DES‐based HIPEs approach is a promising method that encourages further investigation for the synthesis of biodegradable and biocompatible scaffolds nanocomposites for tissue engineering purposes.