Hyperthermia-triggered NO release based on Cu-doped polypyrrole for synergistic catalytic/gas cancer therapy.

Nitric oxide (NO) is a crucial gaseous medium for tumor growth and progression, but it may also cause mitochondrial disorder and DNA damage by drastically increasing its concentration in tumor. Due to its challenging administration and unpredictable release, NO based gas therapy is difficult to eliminate malignant tumor at low safe doses. To address these issues, herein, we develop a multifunctional nanocatalyst called Cu-doped polypyrrole (CuP) as an intelligent nanoplatform (CuP-B@P) to deliver the NO precursor BNN6 and specifically release NO in tumors. Under the aberrant metabolic environment of tumors, CuP-B@P catalyzes the conversion of antioxidant GSH into GSSG and excess H2O2 into ·OH through Cu+/Cu2+ cycle, which results in oxidative damage to tumor cells and the concomitant release of cargo BNN6. More importantly, after laser exposure, nanocatalyst CuP can absorb and convert photons into hyperthermia, which in turn, accelerates the aforesaid catalytic efficiency and pyrolyzes BNN6 into NO. Under the synergistic effect of hyperthermia, oxidative damage, and NO burst, almost complete tumor elimination is achieved in vivo with negligible toxicity to body. Such an ingenious combination of NO prodrug and nanocatalytic medicine provides a new insight into the development of NO based therapeutic strategies. STATEMENT OF SIGNIFICANCE: A hyperthermia-responsive NO delivery nanoplatform (CuP-B@P) based on Cu-doped polypyrrole was designed and fabricated, in which CuP catalyzed the conversion of H2O2 and GSH into ·OH and GSSG to induce intratumoral oxidative damage. After laser irradiation, hyperthermia ablation and responsive release of NO further coupled with oxidative damage to eliminate malignant tumors. This versatile nanoplatform provides new insights into the combined application of catalytic medicine and gas therapy.

Polypyrrole Nanoenzymes as Tumor Microenvironment Modulators to Reprogram Macrophage and Potentiate Immunotherapy.

Nanozyme-based tumor catalytic therapy has attracted widespread attention in recent years, but its therapeutic outcome is drastically diminished by species of nanozyme, concentration of substrate, pH value, and reaction temperature, etc. Herein, a novel Cu-doped polypyrrole nanozyme (CuP) with trienzyme-like activities, including catalase (CAT), glutathione peroxidase (GPx), and peroxidase (POD), is first proposed by a straightforward one-step procedure, which can specifically promote O2 and ·OH elevation but glutathione (GSH) reduction in tumor microenvironment (TME), causing irreversible oxidative stress damage to tumor cells and reversing the redox balance. The PEGylated CuP nanozyme (CuPP) has been demonstrated to efficiently reverse immunosuppressive TME by overcoming tumor hypoxia and re-educating macrophage from pro-tumoral M2 to anti-tumoral M1 phenotype. More importantly, CuPP exhibits hyperthermia-enhanced enzyme-mimic catalytic and immunoregulatory activities, which results in intense immune responses and almost complete tumor inhibition by further combining with αPD-L1. This work opens intriguing perspectives not only in enzyme-catalytic nanomedicine but also in macrophage-based tumor immunotherapy.

[Mechanism of Duhuo Jisheng decotion in delaying degeneration of nucleus pulposus cells in human intervertebral disc].

This paper aimed to investigate the role of Duhuo Jisheng decotion (DHJSD) in delaying human disc degeneration and its possible molecular mechanism. The intervertebral disc specimens were divided into normal and degenerated groups according to Pfirrmann classfication. The expressions of TNF-α, IL-1ß, MMP-3 and MMP-13 in intervertebral disc tissue were detected by Western blot and PCR. Then degenerated human primary NPCs were cultured in vitro, the viability of NPCs treated with stromal cell-derived factor-1 (SDF-1，10 µg·L⁻¹)and various concentrations of DHJSD was assessed by the CCK-8 assay, and the appropriate concentration was screened. The experiment was divided into three groups, control group, SDF-1 group and DHJSD plus SDF-1 group. The levels of TNF-α, IL-1ß, Agg, coIⅡ, MMP-3 and MMP-13 were detected. The levels of CXCR4, NF-κB major groups P65 phosphorylation (p-P65) and nuclear translocation, after treated with CXCR4 siRNA and NF-κB inhibitor (BAY11-7082) were measured by Western blot and immunofluorescence. At the same time, the expression of cell inflammatory factors and extracellular matrix were also measured. The expressions of TNF-α, IL-1ß, MMP-3 and MMP-13 in the degenerated intervertebral disc tissue were significantly increased. In vitro study, the results of CCK-8 indicated that the viability of NPCs was significantly increased when DHJSD concentration was 300 mg·L⁻¹. After the experiment was divided into three groups, compared with SDF-1 group, the expressions of TNF-α, IL-1ß, MMP-3 and MMP-13 in DHJSD group were significantly decreased, but the expressions of Agg, coIⅡ were significantly increased. When CXCR4-siRNA was transfected into NPCs, SDF-1 increased expressions of CXCR4 and p-P65 and inhibited nuclear translocation of P65, whose effect was suppressed by CXCR4-siRNA and DHJSD. In addition, when BAY11-7082 was used to treat NPCs, the expression of TNF-α, IL-1ß, MMP-3 and MMP-13 were significantly decreased. DHJSD could inhibit the production of inflammatory factors and promote the synthesis of extracellular matrix. The potential mechanism may be related to the SDF-1/CXCR4/NF-κB signaling pathway.

Duhuo Jisheng Decoction inhibits SDF-1-induced inflammation and matrix degradation in human degenerative nucleus pulposus cells in vitro through the CXCR4/NF-κB pathway.

Lower back pain (LBP) is the most common disease in orthopedic clinics world-wide. A classic Fangji of traditional Chinese medicine, Duhuo Jisheng Decoction (DHJSD), has been proven clinically effective for LBP but its therapeutic mechanisms remain unclear. We hypothesized that DHJSD might relieve LBP through inhibiting the exaggerated proinflammatory cytokines and extracellular matrix (ECM) degradation. Thus, we studied the effects of DHJSD on stromal cell-derived factor-1 (SDF-1)-induced inflammation and ECM degradation in human nucleus pulposus cells (hNPCs). The primary hNPCs were isolated from either degenerated human intervertebral disc (HID) of LBP patients or normal HID of lumbar vertebral fracture patients, and cultured in vitro. The cells were treated with SDF-1 (10 ng/mL) and subsequently with different concentrations (100-500 µg/mL) of DHJSD for 24 h, respectively. We found that application of DHJSD significantly antagonized the SDF-1-induced production of proinflammatory cytokines and reduction of aggrecan and type II collagen in the hNPCs. DHJSD also markedly reduced the SDF-1-induced increase of CXCR4 and p-p65 and inhibited the nuclear translocation of p65 in the hNPCs. DHJSD, CXCR4-siRNA, and NF-κB inhibitor (BAY11-7082) caused the same inhibition of exaggerated proinflammatory cytokines in the SDF-1-treated hNPCs. These results provided compelling evidence that DHJSD may inhibit the generation of proinflammatory mediators and ECM degradation of HID through an orchestrated targeting at multiple molecules in the SDF-1/CXCR4/NF-κB pathway, thus offered novel mechanistic insights into the clinical effectiveness of DHJSD on LBP.