Nanometric and monodisperse starch acetate nanospheres can be prepared through a simple procedure of nanoprecipitation, by the dropwise addition of water to an acetone solution of starch acetate, without any stabilizing agent. This is the first report of the preparation of starch-based nanospheres by this method. The size of the nanospheres obtained can be easily controlled by a number of simple and efficient modifications, i.e., through regulation of the polymer concentration in acetone, the proportions of the water and organic phases, and the molecular weight and degree of substitution of the starch esters. A number of reasons are suggested to explain the observed transitions in the particle size. Fluorescence spectroscopic studies proved that these types of nanospheres could be potentially used for the encapsulation of hydrophobic drugs.

A robust method to prepare hydrogels with high mechanical strength is presented. Core/shell nanospheres with derivatizable allyl groups in the shell were first prepared. Starch‐based nanospheres were used as crosslinker to prepare polyacrylamide hydrogels. The starch‐based nanospheres were bridged by acrylamide to form crosslink points in the hydrogel network. They possess an extremely high mechanical strength. The results show that starch‐based nanosphere hydrogels can sustain strengths of 10.34 MPa, which is 60 times greater than for a normal hydrogel. The mechanical properties of SNH can be tailored by varying the content of SN. This approach offered a new way of making functional hydrogel with biodegradable component as a substitute for tissue.magnified image

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