CCR3 and allergic rhinitis: Furthermore, Teng et al. [84] selected PVA as a backbone molecule (P) and grafted pH-cleavable hydrophilic terminal mPEG2000-Hyd-SH (H) and CCR3 antagonist peptide (C), which inhibit eosinophil (EOS) chemotaxis, to prepare ketotifen (KT) nanoparticles (PHCK) for the treatment of allergic rhinitis (Figure 2B).