Multilayered polyelectrolyte poly(sodium 4-styrenesulfonate)/poly(allylamine hydrochloride) microcapsules prepared using layer-by-layer (LbL) assembly technology were filled by UV-photopolymerization of acrylamide derivatives directly into the capsule interior. Influences of component properties and polymerization conditions on the structure of the obtained composites are discussed. Mixing formed polymer chains with the capsule wall material stabilizes the initial wall conformation and lowers capsule sensitivity to environmental conditions.