The structure and dynamics of poly(N-isopropylacrylamide-co-acrylic acid) (NIPAm/AAc) gels prepared either by cross-linker-free UV-induced polymerization or by redox polymerization were compared using swelling measurement and dynamic/static light scattering. Either AAc monomer or AAc polymer units are included in the polymer network. As a result, four types of NIPAm/AAc gels were obtained, namely (A) redox-mono, (B) UV-mono, (C) redox-poly, and (D) UV-poly. A is the reference polymer mostly investigated in the literature. The following facts emerged: Compared to A, B contains a large portion of defects, e.g., dangling chains, loops and branched chains, which leads to characteristic behavior, i.e., (i) larger swelling ratio and (ii) stronger temperature dependence of the spatial inhomogeneities. Charged groups in both C and D are topologically localized on AAc polymer chains, which result in different temperature dependencies of the structure and dynamics.