Upon synthesis of a polymeric matrix with pH and temperature responsiveness and antioxidant bioactivity based on poly(maleic anhydride-co-3,9-divinyl-2,4,8,10-tetraoxaspiro [5.5] undecane) derivatives.

Poly(maleic anhydride-co-3,9-divinyl-2,4,8,10-tetraoxaspiro [5.5] undecane), acquired through radical polymerization, was synthesized with the aim to prepare an alternant copolymer with precise placement of functional groups along the polymer backbones. The new structure owing to the suitable and specific functionalities is anticipated to be used as reactive polymer to link bioactive compounds via maleic anhydride moiety. The copolymer was improved in its functionality by maleic anhydride ring opening with different amounts of erythritol in order to confer antioxidant characteristics to the polymeric structure. The chemical structure of the new prepared polymers was confirmed by FTIR and (1)H NMR spectra, and the polymers were also characterized from the viewpoint of their thermal stability. The dual sensitivity of the polymeric structure, at temperature and pH, was evaluated by determining the hydrodynamic radius and zeta potential in interdependence with the environment conditions. The polymer morphology was investigated by SEM. The antioxidant character was evaluated measuring the scavenger properties of the functionalized copolymer with erythritol against the 2,2-diphenyl-1-picrylhydrazyl radicals. The acute toxicity investigation, realized in vivo for the copolymer and the derivatives, allows the inclusion of the compounds into the group of moderately toxic accordingly to Hodge and Sterner toxicity scale owing to the lethal dose 50 determined values.