Acid-labile poly(N-vinyl formamide) (“PNVF”) nanocapsules were synthesized by free radical polymerization of N-vinyl formamide with optional active ingredients on the surface of silica nanoparticles. Polymerization in the presence of a novel cross-linker that contains an acid-labile ketal facilitated stable etching of silica nanoparticle templates using sodium hydroxide and recovery of PNVF nanocapsules. The formamido side group of PNVF was then hydrolyzed by extended exposure to sodium hydroxide to produce polyvinylamine (“PVAm”) nanocapsules. PNVF and PVAm nanoparticles are also synthesized that form nanogels with optional active ingredients.