beta-Cyclodextrin polymer, namely nanosponges (NSs), were synthesized using two cross-linkers: 1,1'-carbonyldiimidazole (CDI) and pyromellitic dianhydride (PMDA). The synthesized NSs were complexed with N,N-diethyl-meta-toluamide (DEET) and, after complex characterization, the NSs cross-linked with CDI were found more effective than those cross-linked with PMDA in terms of encapsulation efficiency and loading capacity. The CDI-NSs were dispersed in a polyacrylic resin, which was thermally polymerized on a polyester fabric surface. The fabric functionalization was evaluated through quantification of DEET extracted from the polyester fabrics, before and after three washing cycles. The results showed that encapsulation into NSs prolongs the persistence of DEET on polyester fabrics.