Conjugation of antioxidant molecule to PEGylated NPs for pH dependent drug release

Abstract This paper reports the encapsulation of antioxidant molecule Quercetin on PEG-diamine coated nanoparticles (NPs) by aqueous synthesis method to improve itʼs poor water solubility and stability. Two types of PEGylated NPs (PEGylated CdSe and PEGylated CdSe/CdS) have been used to conjugate Quercetin. The synthesis have been done using two different approaches, in first case organic solvent DMSO along with DI (De-Ionized) water have been used to dissolve Quercetin whereas during the second procedure DI water have been solely used to dissolve Quercetin. UV–vis absorption spectroscopy, TEM and IR results give the confirmation of conjugation of Quercetin to PEGylated NPs. Controlled release has been observed for both pH environments with a maximum release for CPD-I with 95.89% at pH 7.4 whereas at pH 5 CCPD-I shows maximum release i.e. 76.10%. The antioxidant activity results provide that the Quercetin molecules retain their antioxidant properties after conjugation with PEGylated NPs.