Reversal of pancreatic desmoplasia by a tumour stroma-targeted nitric oxide nanogel overcomes TRAIL resistance in pancreatic tumours.

OBJECTIVE: Stromal barriers, such as the abundant desmoplastic stroma that is characteristic of pancreatic ductal adenocarcinoma (PDAC), can block the delivery and decrease the tumour-penetrating ability of therapeutics such as tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), which can selectively induce cancer cell apoptosis. This study aimed to develop a TRAIL-based nanotherapy that not only eliminated the extracellular matrix barrier to increase TRAIL delivery into tumours but also blocked antiapoptotic mechanisms to overcome TRAIL resistance in PDAC. DESIGN: Nitric oxide (NO) plays a role in preventing tissue desmoplasia and could thus be delivered to disrupt the stromal barrier and improve TRAIL delivery in PDAC. We applied an in vitro-in vivo combinatorial phage display technique to identify novel peptide ligands to target the desmoplastic stroma in both murine and human orthotopic PDAC. We then constructed a stroma-targeted nanogel modified with phage display-identified tumour stroma-targeting peptides to co-deliver NO and TRAIL to PDAC and examined the anticancer effect in three-dimensional spheroid cultures in vitro and in orthotopic PDAC models in vivo. RESULTS: The delivery of NO to the PDAC tumour stroma resulted in reprogramming of activated pancreatic stellate cells, alleviation of tumour desmoplasia and downregulation of antiapoptotic BCL-2 protein expression, thereby facilitating tumour penetration by TRAIL and substantially enhancing the antitumour efficacy of TRAIL therapy. CONCLUSION: The co-delivery of TRAIL and NO by a stroma-targeted nanogel that remodels the fibrotic tumour microenvironment and suppresses tumour growth has the potential to be translated into a safe and promising treatment for PDAC.

Photodynamic antitumor activity of Gallium(III) and Phosphorus(V) complexes of trimethoxyl A2B triaryl corrole.

Two new trimethoxyl A2B triaryl corroles 10-(2,4,6-trimethoxyphenyl)-5,15-bis(pentafluorophenyl)- corrole (1) and 10-(3,4,5-trimethoxyphenyl)-5,15-bis(pentafluorophenyl)-corrole (2) and their gallium(III) and phosphorus(V) (1-Ga, 1-P, 2-Ga and 2-P) complexes had been prepared and well characterized by UV-vis, NMR and HR-MS. Among all compounds, 2-Ga, 1-P and 2-P showed excellent in vivo photodynamic activity against the MDA-MB-231, A549, Hela and HepG2 cell lines upon light irradiation at 625 nm. And 2-P even exhibited higher phototoxicity than the clinical photosensitizer temoporfin. Also, 2-P exhibited the highest singlet oxygen quantum yield and photostability. The preliminary investigation revealed that 2-P could be rapidly absorbed by tumor cells and mainly located in the cytoplasm. After photodynamic therapy (PDT) treatment with 2-P, mitochondrial membrane potential destruction, intracellular ROS level increasing and nuclear fragmentation of cancer cells could be observed. Cell cycle analysis demonstrated that the 2-P PDT may cause tumor cell arrest at sub-G1 stage and induce early and late apoptosis of cells. These results suggest that 2-P is a promising candidate as a photosensitizer for photodynamic therapy.

Halogenated Gallium Corroles:DNA Interaction and Photodynamic Antitumor Activity.

A series of halogenated gallium corroles were synthesized and characterized by UV-vis, HRMS, NMR, and FT-IR. The interaction between these gallium corroles and calf thymus DNA had been investigated by spectroscopic methods. These gallium corroles would interact with CT-DNA via an outside binding mode. The photodynamic antitumor activity in vitro of these gallium corroles toward different cell lines had also been tested. 3-Ga displayed low cytotoxicity to normal cells under both light and dark conditions but high phototoxicity to liver cancer cells HepG2. The vitro experiment results showed that 3-Ga could be efficiently absorbed by tumor cells. After light illumination, it may induce reactive oxygen species (ROS) and cause destruction of the mitochondrial membrane potential, which may finally trigger tumor cell apoptosis. Flow cytometry results showed that HepG2 cells were mainly distributed in the sub-G0 phase, which corresponds to cells with highly fragmented DNA or dead cells generally. This suggests that 3-Ga could lead to tumor cell apoptosis after light illumination.

DNA interaction and photodynamic antitumor activity of transition metal mono-hydroxyl corrole.

A series of iron(III), manganese(III) and copper(III) mono-hydroxyl corrole complexes had been prepared and well characterized by UV-vis, 1H NMR, 19F NMR and HR-MS. These metallocorroles may bind to CT-DNA through external binding mode. Metallocorrole Fe-2c exhibited significant phototoxicity and low toxicity toward A549 tumor cells. While manganese (III) and copper (III) corroles showed hypotoxicity to A549, MCF-7 and HepG-2 tumor cells, whether under dark or illumination conditions. All tested metallocorroles exhibited non-toxicity to human normal cells (GES-1) with or without irradiation at 625 nm. Cell cycle analysis indicated that metallocorrole Fe-2c arrested the cell cycle at G2/M phase and increased the Sub-G1 phase in A549 cell lines. It was mainly localized at mitochondria and could significantly reduce mitochondrial membrane potential after photodynamic treatment, which would further induce tumor cell apoptosis.

Construction of 5-Fluorouracil and Gallium Corrole Conjugates for Enhanced Photodynamic Therapy.

Molecular hybridization is a well-established strategy for developing new drugs. In the pursuit of promising photosensitizers (PSs) with enhanced photodynamic therapy (PDT) efficiency, a series of novel 5-fluorouracil (5FU) gallium corrole conjugates (1-Ga-4-Ga) were designed and synthesized by hybridizing a chemotherapeutic drug and PSs. Their photodynamic antitumor activity was also evaluated. The most active complex (2-Ga) possesses a low IC50 value of 0.185 µM and a phototoxic index of 541 against HepG2 cells. Additionally, the 5FU-gallium corrole conjugate (2-Ga) exhibited a synergistic increase in cytotoxicity under irradiation. Excitedly, treatment of HepG2 tumor-bearing mice with 2-Ga under irradiation could completely ablate tumors without harming normal tissues. 2-Ga-mediated PDT could disrupt mitochondrial function, cause cell cycle arrest in the sub-G1 phase, and activate the cell apoptosis pathway by upregulating the cleaved PARP expression and the Bax/Bcl-2 ratios. This work provides a useful strategy for the design of new corrole-based chemo-photodynamic therapy drugs.

Azide-modified corrole phosphorus complexes for endoplasmic reticulum-targeted fluorescence bioimaging and effective cancer photodynamic therapy.

Study on corrole photosensitizers (PSs) for photodynamic therapy (PDT) has made remarkable progress. Targeted delivery of PSs is of great significance for enhancing therapeutic efficiency, decreasing the dosage, and reducing systemic toxicity during PDT. The development of PSs that can be specifically delivered to the subcellular organelle is still an attractive and challenging work. Herein, we synthesize a series of azide-modified corrole phosphorus and gallium complex PSs, in which phosphorus corrole 2-P could not only precisely target the endoplasmic reticulum (ER) with a Pearson correlation coefficient (PCC) up to 0.92 but also possesses the highest singlet oxygen quantum yields (ΦΔ = 0.75). This renders it remarkable PDT activity at a very low dosage (IC50 = 23 nM) towards HepG2 tumor cell line while ablating solid tumors in vivo with excellent biosecurity. Furthermore, 2-P exhibits intense red fluorescence (ΦF = 0.25), outstanding photostability, and a large Stokes shift (190 nm), making it a promising fluorescent probe for ER. This study provides a clinically potential photosensitizer for cancer photodynamic therapy and a promising ER fluorescent probe for bioimaging.

Gallium(III) Amide Corroles: DNA Interaction and Photodynamic Activity in Cancer Cells.

A series of gallium(III) amide corroles including meso-5,15-bis(pentafluorophenyl)-10-(4-Pyridinamide-phenyl)corrole gallium (III) (1-Ga), meso-5,15-bis(pentafluorophenyl)-10-(4-Furamide-phenyl)corrole gallium(III) (2-Ga) and meso-5,15-bis(pentafluorophenyl)-10-(4-Thiophenamide-phenyl)corrole gallium(III) (3-Ga) were synthesized. The interaction of these complexes with DNA and their photodynamic antitumor activities have been studied. UV spectra titration showed that these gallium(III) corroles interact with calf thymus DNA (CT-DNA) through an external binding mode. All three gallium(III) corroles can effectively generate singlet oxygen under illumination and have good photostability. Among the three gallium(III) corroles, 2-Ga exhibited excellent photodynamic antitumor activity against the tested tumor cell lines under light irradiation (625±2 nm, 0.3 mW/cm2 , 1.08 J/cm2 ). The best phototoxicity was observed by 2-Ga against HepG2 cells (IC50 =6.3±0.9), which is even better than temoporfin (IC50 =8.4±1.8). It could block HepG2 cells in the sub-G0 phase and effectively induce apoptosis of HepG2 cells under 625 nm light irradiation.

Photodynamic Antitumor Activity of 5,15-Bis(perfluorophenyl)-10-(4-carboxyphenyl)corrole and its Gallium(III) and Phosphorus(V) Complexes.

This work reports the preparation and characterization of an A2 B corrole 5,15-bis(perfluorophenyl)-10-(4-carboxyphenyl)corrole and its gallium(III) and phosphorus(V) complexes. Their in-vitro photodynamic anticancer activities against A549, MDA-MB-231, B16, HepG2, and Hela cell lines were also investigated. Among three compounds, phosphorus(V) complexexhibits the best photostability, highest fluorescence quantum yields (ΦF =0.138), and the highest singlet-oxygen quantum yields (ΦΔ =0.87). Also, the phosphorus(V) complex exhibits the best photodynamic antitumor activity against MDA-MB-231 cells with a low IC50 (0.08 µM) upon light irradiation at 625±2 nm, which is much lower than commercial PDT drug Temoporfin (0.1 µM) at the same conditions. The cellular localization assay confirmed that the phosphorus(V) complexis mainly distributed in the cytoplasm and have a good ability to produce reactive oxygen species (ROS) under light illumination, which would further cause oxidative damage to tumor cells and finally result in the apoptosis. After PDT treatment, phosphorus(V) complex may cause tumor cell arrest at the G2/M stage. The preliminary results showed phosphorus(V) corrole complex is a good candidate for photodynamic therapy (PDT) of tumors.

Delivery of sorafenib by myofibroblast-targeted nanoparticles for the treatment of renal fibrosis.

Fibrosis is an excessive accumulation of the extracellular matrix within solid organs in response to injury and a common pathway that leads functional failure. No clinically approved agent is available to reverse or even prevent this process. Herein, we report a nanotechnology-based approach that utilizes a drug carrier to deliver a therapeutic cargo specifically to fibrotic kidneys, thereby improving the antifibrotic effect of the drug and reducing systemic toxicity. We first adopted in vitro-in vivo combinatorial phage display technology to identify peptide ligands that target myofibroblasts in mouse unilateral ureteral obstruction (UUO)-induced fibrotic kidneys. We then engineered lipid-coated poly(lactic-co-glycolic acid) nanoparticles (NPs) with fibrotic kidney-homing peptides on the surface and sorafenib, a potent antineoplastic multikinase inhibitor, encapsulated in the core. Sorafenib loaded in the myofibroblast-targeted NPs significantly reduced the infiltration of α-smooth muscle actin-expressing myofibroblasts and deposition of collagen I in UUO-treated kidneys and enhanced renal plasma flow measured by Technetium-99m mercaptoacetyltriglycine scintigraphy. This study demonstrates the therapeutic potential of the newly identified peptide fragments as anchors to target myofibroblasts and represents a strategic advance for selective delivery of sorafenib to treat renal fibrosis. SIGNIFICANCE STATEMENT: Renal fibrosis is a pathological feature accounting for the majority of issues in chronic kidney disease (CKD), which may progress to end-stage renal disease (ESRD). This manuscript describes a myofibroblast-targeting drug delivery system modified with phage-displayed fibrotic kidney-homing peptides. By loading the myofibroblast-targeting nanoparticles (NPs) with sorafenib, a multikinase inhibitor, the NPs could suppress collagen synthesis in cultured human myofibroblasts. When given intravenously to mice with UUO-induced renal fibrosis, sorafenib loaded in myofibroblast-targeting NPs significantly ameliorated renal fibrosis. This approach provides an efficient therapeutic option to renal fibrosis. The myofibroblast-targeting peptide ligands and nanoscale drug carriers may be translated into clinical application in the future.

Hydroxy-corrole and its gallium(III) complex as new photosensitizer for photodynamic therapy against breast carcinoma.

Three mono-hydroxy corroles 1-3 and their gallium(III) complexes Ga1-3 were synthesized, and their photodynamic antitumour activities towards breast cancer cells were investigated. All corroles showed excellent cytotoxicity against the MDA-MB-231 and 4T1 cell lines upon light irradiation at 625 nm. Ga3 exhibited excellent phototoxicity and selectivity against MDA-MB-231 cells, with an IC50 of 0.06 ± 0.03 µM and a selective index value of 1338.83 (relative to human normal Huvec cells). The performance of Ga3 was even better than that of the clinical photodynamic therapy drug m-THPC. A preliminary mechanistic investigation revealed that corrole 3 and Ga3 were mainly located in the cytoplasm. Upon irradiation, they could generate intracellular reactive oxygen to destroy the mitochondrial membrane potential and arrest the cell cycle at the sub-G1 phase. Flow cytometry revealed that corrole 3 and Ga3 induced cancer cell apoptosis after photodynamic treatment. Corrole 3 and Ga3 displayed negligible cytotoxicity in the dark. These results suggest that corrole 3 and Ga3 are promising candidates for use in the photodynamic therapy of breast cancer.

[Cloning of alpha-bungarotoxin gene and its prokaryotic expression as a non-fusion protein].

On the basis of the reported amino acid sequence of alpha-bungarotoxin (alpha-BGT), DNA sequence of alpha-BGT was deduced and fourteen partially complementary oligonucleotides were designed and synthesized. A plasmid carrying the coding region of alpha-BGT was obtained by primer extension, PCR and ligation with pMD-18-T. The target fragment was digested with Xba I and EcoR I, recovered and ligated with pET28a(+). The resultant expression vector was transformed into BL21 (DE3), BL21 (DE3) Codon plus, and BL21 (DE3) plysS, respectively. Recombinant alpha-BGT was expressed in BL21 (DE3) and was analyzed by 15% Tris/tricine SDS-PAGE. The result showed that the recombinant protein, mostly found in inclusion bodies, accounted for 11.98% of the total bacterial lysate. The expression capacity could be increased to 16.28% by optimizing expression conditions. Western blotting results showed that the expressed protein had similar immunogenicity with the natural alpha-BGT protein purified from the venom of Krait Bungarus spp. In vivo toxicity assay of purified and renatured proteins in mice showed that LD50 was about 1.28 microg/g.