A novel method for synthesizing nanoscale polymer networks that swell in acidic media is described here sing photoinitiated emulsion polymerization. These nanomatrices consist of a cross-linked core of poly[2- (diethylamino)ethyl methacrylate] surface grafted with poly(ethylene glycol) (PDGP) with an average diameter of 50-150 nm. Control over mesh size, surface charge, encapsulation efficiency, and in vitro biocompatibility was obtained by varying cross-linking density. The ability to image nanomatrices in their dry state using conventional scanning electron microscopy was made possible by increasing cross-linking density. Theoretical calculations of matrix mesh sizes were supported by the encapsulation of both insulin and colloidal gold 2-5 nm in diameter. To ability to sequester and control the aggregation of an inorganic phase confirmed their use as a nanocomposite matrix material. These networks could be used as imaging agents, drug delivery devices, or components of sensing devices.