Hydrogels in the nano regime are termed as nanogels (NGs). The formulation in the nano range renders the synthesis process easy as well as scalable with better control over designing/cross-linking between the NGs. Nanogels have shown controllable swelling, viscoelasticity, and high biocompatibility leading to their use in targeted and stimuli-responsive drug delivery purposes. The designing and engineering of materials plays a pivotal role in accounting for the improvement in the basic properties of the materials and hence, is very important for material scientists. The study of the design and functional characteristics of NGs is the only way to understand their chemical and biological responses in biological models and in turn helps to generate a rationale for development of smart NGs and therapeutic inventions.