Table 3.

Aryl Boronic Ester-Based Oxidation-Responsive Systems

Polymer structure	Formulation	Oxidant	Response to oxidation	Evidence of degradation	Ref.
Modified dextran	100 nm NPs	1 mM H2O2	Cleavage of boronic ester yields water-soluble dextran	NMR of NP, t1/2=4 h	(17)
				OD of NP, t1/2=36 min
Modified polycresol	150 nm NPs	50, 100 μM, and 1 mM H2O2	Degradation into small molecules on quinone methide rearrangement	NR quenching	(45)
				t1/2 ∼ 45 h at 50 μM H2O2
				t1/2 ∼ 30 h at 100 μM H2O2
				t1/2 ∼ 10 h at 1 mM H2O2
				Paclitaxel release
				63% at 50 μM H2O2 (3 days)
				97% at 1 mM H2O2 (2 days)
				23% (2 days) in PBS only
				NMR of polymer, complete degradation within 3 days, 50 mM H2O2
				TEM of NP, particle deformation within 3 days, 1 mM H2O2

NPs, nanoparticles, NR, Nile red; OD, optical density; PBS, phosphate-buffered saline.