Mixtures of a nonionic surfactant and non-functionalized nanohydroxyapatite (NHA) enhanced the stability of oil-in-eutectic mixture high internal phase emulsions (HIPEs). Upon ring opening polymerization of the eutectic mixture composed of l-lactide and ε-caprolactone, biodegradable polyHIPEs with specific cavity sizes and selective interfacial functionalization with NHA are produced.