Nanoparticles Prepared From Pterostilbene (PTE): A New Strategy for Reducing Blood Glucose and Improving Diabetic Complications

Abstract

Aim: New envisions are put forward on the cross application of plant extracts and biomaterials, especially new conjectures are put forward on glucose lowering nanodrug delivery systems.Study design and methods: In this study, pterostilbene (PTE) was esterified with acryloyl chloride firstly, and then 3-acrylamidophenyl boric acid (AAPBA) and PTE esterified by acryloyl chloride were copolymerized into p(AAPBA-b-PTE). The characterization and structure of its polymer were examined. Additionally, p(AAPBA-b-PTE) nanoparticles and insulin loaded p(AAPBA-b-PTE) nanoparticles were prepared. The properties of pH, temperature and glucose sensitivity were investigated. And tested the drug loading and release of NPs. The nanoparticle toxicity was observed through cell and animal experiments, and the nanoparticle biodegradation process under physiological conditions was also observed. Finally, the effects of NPs on reducing blood sugar, antioxidation and improving micro inflammation were investigated in vivo.Results: Based on PTE, we successfully synthesized p(AAPBA-b-PTE) NPs. The NPs were basically round in shape with sizes between 150 and 250 nm. It has good pH and glucose sensitivity. The entrapment efficiency (EE) of insulin loaded NPs is about 56%, and the drug loading (LC) is about 13%. The highest release of insulin was 70%, and the highest release of PTE was 85%. Meanwhile, the insulin could undergo self-regulation according to the change of glucose concentration, thus achieving an effective and sustained release. Both in vivo and in vitro experiments showed that the NPs were safe and nontoxic. Under physiological conditions, it can be completely degraded within 40 days. Fourteen days after the mice were injected with p(AAPBA-b-PTE) NPs, there were no obvious abnormalities in the heart, liver, spleen, lung, and kidney. Moreover, the NPs can effectively reduce blood glucose, improve the antioxidant capacity and improve the micro inflammation status in mice.Conclusions: Using PTE as raw material, p(AAPBA-b-PTE) NPs were successfully prepared, which can effectively reduce blood glucose, improve antioxidant capacity, and reduce inflammatory response. It provided a new way for the combination of plant extracts and biomaterials to regulate and treat diseases through NPs or other dosage forms.