The combination of thermoresponsive polymers with natural biomaterials can extend the properties portfolio, especially in the field of biomedicine, where a great cell adhesiveness and biodegradation is necessary for bone regeneration. The poly(N-isopropylacrylamide)-grafted-gelatin gels were already reported where several synthetic parameters, such as polymer or gelatin were varied and final properties were studied. Nevertheless, the ratio of the cross-linker was always the same, and consequently, their properties were not analyzed yet. There are various preparation methods of these systems but microwave synthesis was not deeply studied, and consequently, important benefits can be obtained due to its efficiency and time saving. In this work, we modified the ratio of cross-linker and important changes are observed in the thermoresponsive and mechanical properties tested by calorimetry, thermogravimetry, rheology, and atomic force microscopy. The amount of cross-linker modulates the homogeneity of the resulting gels, and consequently, the lower critical solution temperature, the absorption of water into surfaces and the mechanical behavior of the new materials.