**3. Synthesis and classification of CD-NSs**

The choice of appropriate synthetic conditions, allowed to obtain both watersoluble and water-insoluble polymer products, known also as CD-NSs or insoluble, and branched or soluble polymer [30–32]. The latter case allowed to overcome the limits of pristine CDs in terms of solubility in water and specific organic solvent, while the resulting formation of a three-dimensional cross-linked network was related to the presence of interstitial spaces among the monomers [33]. In this regard, the nature of the cross-linker and its amount in respect to the CD, ratio which defines the so-called cross-linking density, are presented to have a great impact on the properties and structure of the final material [34]. Also, being said interstices wider and more hydrophilic in respect to the cavities of CDs, a wider hosting capability was observed as a result.
