With the improvement of people’s living standards, obesity has become a health threat, but an effective drug treatment for obesity has not been found yet. Here, we suggest the use of celastrol, a pentacyclic triterpenoid from the traditional Chinese medicine Tripterygium wilfordii, which has a powerful antiobesity effect. Increasing studies have discovered that obesity is closely related to inflammation. In addition, MMP-2 enzyme is highly expressed in inflammatory sites. According to the principle of the prodrug, celastrol was used as a hydrophobic group, PVGLIG as a link, and dextran sulfate as a hydrophilic group to form a micelle (DS-PVGLIG-Cel). Celastrol was then loaded for the effective treatment of high-fat-diet (HFD)-induced obesity. MMP-2-sensitive assays confirmed that PVGLIG cleavage by MMP-2 enzymes favors the synchronous release of celastrol. A series of animal experiments tested that the preparation group has a strong weight loss effect. Our results suggest that this will shed light on a strategy for the subsequent effective treatment of HFD obesity.
Jiaojiao Chen,Yarong Song,Wenqian Yang,Jianhui Guo,Saihui Zhang,Dong Wan,Yonghui Liu,Jie Pan
Chemotherapy remains the primary treatment for cancer; however, conventional chemotherapeutic drugs have several shortcomings, including poor solubility, lack of targeting, low bioavailability, and high toxicity to healthy tissues. In order to overcome these limitations, drug delivery systems (DDS) have emerged as a promising alternative. In this study, we synthesized TPGS3350-PVGLIG-SS-DOX polymeric micelles that incorporate both extracellular MMP2/9 enzyme response and intracellular reduction response at a nanoscale level. The micelles remained stable throughout the blood circulation and only aggregated at the tumor sites, thanks to the enhanced permeability and retention (EPR) effect. Moreover, the tumor tissue showed a high expression of MMP2/9 enzymes, which resulted in the cleavage of the PVGLIG peptide sequence, ultimately leading to an improved phagocytosis efficiency. Under the action of high intracellular GSH concentration, the disulfide bond was broken and DOX was released to induce tumor cell death. The TPSD&D micelles exhibited good tumor inhibitory activity in vivo and significantly reduced toxic side effects on normal tissues. Our work provides a simple method to assemble tumor-targeted prodrug micelles to improve cancer therapy, which holds potential for clinical applications in antitumor therapy.
Jing-Bo Hu,Di Liu,Jing Qi,Kong-jun Lu,Fei-yang Jin,Xiao-Ying Ying,Jian You,Yong-Zhong Du
Based on the overproduction of matrix metalloproteinase-2 (MMP-2) in renal tissue during acute kidney injury (AKI) occurrence, we developed a MMP-2 enzyme-triggered polymeric prodrug with sialic acid (SA) as the targeting group to the inflamed vascular endothelial cells for enhanced therapeutic outcomes. An MMP-2-responsive peptide, PVGLIG, was used to endow the polymeric prodrug with the ability to rapidly release the anti-inflammatory drug, curcumin (CUR), after the targeted site is reached and to improve the drug concentration in the target tissue. The sialic acid–dextran–PVGLIG–curcumin (SA-DEX-PVGLIG-CUR) polymeric prodrug was successfully synthesized via multi-step chemical reactions and characterized by 1H NMR. The water solubility of CUR was significantly increased in the polymeric prodrug and was approximately 23-fold higher than that of free CUR. The in vitro drug release results showed that the release rate of SA-DEX-PVGLIG-CUR was significantly enhanced compared to that of SA-DEX-CUR in a dissolving medium containing the MMP-2 enzyme, suggesting that SA-DEX-PVGLIG-CUR had rapid drug release characteristics in an inflammatory environment. A cellular uptake test confirmed that SA-DEX-PVGLIG-CUR was effectively internalized by inflamed vascular endothelial cells in comparison with that by normal cells, and the mechanism was associated with the specific interaction between SA and E-selectin receptors specifically expressed on inflamed vascular endothelial cells. Bio-distribution results further demonstrated the rapid and increased renal accumulation of SA-DEX-PVGLIG-CUR in AKI mice. Benefiting from the rapid drug release in renal tissue, SA-DEX-PVGLIG-CUR effectively ameliorated the pathological progression of AKI compared with free CUR and SA-DEX-CUR, as reflected by the improved renal functions, histopathological changes, pro-inflammatory cytokine production, oxidative stress and expression of apoptosis related proteins. Altogether, this study provided a new therapeutic strategy for the treatment of AKI.
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