Recent patents on eggshell: shell and membrane applications.

The chicken eggshell and its membranes are an inexpensive and abundant waste material which exhibit interesting characteristics for many potential applications. The eggshell is formed mainly of calcium carbonate (CaCO3) and is used widely as an animal feed, lime (Ca(OH)2) substitute or a fertilizer. Moreover, the associated eggshell membranes have a high content of bioactive components, as well as properties of moisture retention and biodegradability which have potential use for clinical, cosmetic, nutraceutical and nanotechnology applications. The eggshell membranes have been also used for biosorption of heavy metals and dyes and as a template to synthesize metal nanoparticles. The combination of nanosized calcium phosphate (Ca3(PO4)2) biomaterials synthesized from eggshell and eggshell membrane show promise to develop drug delivery system and nanowires for electronic devices. In addition, a derived product, the soluble eggshell membrane protein (SEP) has applications in tissue engineering. This review discusses the patented applications of eggshell membrane waste: shell and membrane for the last 10 years as well as their future applications.