Interaction and oxidative damage of DVDMS to BSA: a study on the mechanism of photodynamic therapy-induced cell death

MRI Directed Magnevist Effective to Study Toxicity of Gd-Doped Mesoporous Carbon Nanoparticles in Mice Model

Purpose

Magnetic resonance imaging (MRI) has been a valuable and widely used examination technique in clinical diagnosis and prognostic efficacy evaluation. The introduction of MRI contrast agent (CA) improves its sensitivity obviously, particularly with the development of nano-CA, which presents higher contrast enhancement ability. However, systematical evaluation of their toxicity is still limited, hampering their further translation in clinics.

Methods

In this paper, to systematically evaluate the toxicity of nano-CA, Gd-doped mesoporous carbon nanoparticles (Gd-MCNs) prepared by a one-step hard template method were introduced as a model and clinically used MRI CA, Magnevist (Gd-DTPA) as control. Their in vitro blood compatibility, cellular toxicity, DNA damage, oxidative stress, inflammation response as well as in vivo toxicity and MR imaging behaviors were studied and compared.

Results

The experimental results showed that compared with Gd-DTPA, Gd-MCNs displayed negligible influence on the red blood cell shape, aggregation, BSA structure, macrophage morphology and mitochondrial function. Meanwhile, limited ROS and inflammatory cytokine production also illustrated the cellular compatibility of Gd-MCNs. For in vivo toxicity evaluation, Gd-MCNs presented acceptable in vivo biosafety even under 12 times injection for 12 weeks. More importantly, at the same concentration of Gd, Gd-MCNs displayed better contrast enhancement of tumor than Gd-DTPA, mainly coming from its high MRI relaxation rate which is nearly 9 times that of Gd-DTPA.

Conclusion

In this paper, we focus on the toxicity evaluation of MRI nano-CA, Gd-MCNs from different angles. With Gd-DTPA as control, Gd-MCNs appeared to be highly biocompatible and safe nanoparticles that possessed promising potentials for the use of MRI nano-CA. In the future, more research on the long-term genotoxicity and the fate of nanoparticles after being swallowed should be performed.

BODIPY nanoparticles functionalized with lactose for cancer-targeted and fluorescence imaging-guided photodynamic therapy

A series of four lactose-modified BODIPY photosensitizers (PSs) with different substituents (-I, -H, -OCH₃, and -NO₂) in the para-phenyl moiety attached to the meso-position of the BODIPY core were synthesized; the photophysical properties and photodynamic anticancer activities of these sensitizers were investigated, focusing on the electronic properties of the different substituent groups. Compared to parent BODIPY H, iodine substitution (BODIPY I) enhanced the intersystem crossing (ISC) to produce singlet oxygen (¹O₂) due to the heavy atom effect, and maintained a high fluorescence quantum yield (Φ_F) of 0.45. Substitution with the electron-donating methoxy group (BODIPY OMe) results in a significant perturbation of occupied frontier molecular orbitals and consequently achieves higher ¹O₂ generation capability with a high Φ_F of 0.49, while substitution with the electron-withdrawing nitro group (BODIPY NO2) led a perturbation of unoccupied frontier molecular orbitals and induces a forbidden dark S₁ state, which is negative for both fluorescence and ¹O₂ generation efficiencies. The BODIPY PSs formed water-soluble nanoparticles (NPs) functionalized with lactose as liver cancer-targeting ligands. BODIPY I and OMe NPs showed good fluorescence imaging and PDT activity against various tumor cells (HeLa and Huh-7 cells). Collectively, the BODIPY NPs demonstrated high ¹O₂ generation capability and Φ_F may create a new opportunity to develop useful imaging-guided PDT agents for tumor cells.

Sinoporphyrin sodium, a novel sensitizer for photodynamic and sonodynamic therapy

Sinoporphyrin sodium (DVDMS) is a novel sensitizer discovered by Professor Fang Qi-Cheng and widely used in photodynamic (PDT) and sonodynamic therapy (SDT). We searched databases including PubMed, Web of Science, CNKI, etc. for system review of its progress. We found that, both DVDMS-PDT and -SDT had been proven effective for inhibiting tumor growth and mechanisms involved reactive oxygen species, autophagy, and mitochondrial apoptosis pathways. Material advances enhanced antitumor effects and expanded its application. The safety of DVDMS in animals was evaluated, and metabolic parameters were uncovered. Additionally, DVDMS-PDT also exhibited therapeutic effects on non-neoplastic diseases like psoriasis and bacterial infections. Two phase I clinical trials of DVDMS have been documented, but recruitments had still not been completed. In conclusion, DVDMS is a promising sensitizer for both PDT and SDT; however, there are some shortcomings in previous studies like inconsistent treatment parameters, which need systematic assessments in future. Moreover, more mechanisms such as the role of autophagy need to be discovered. Further evidence of the safety and effectiveness of new materials are needed, and the application in non-neoplastic diseases like actinic keratosis and fungal infection deserves further development. Above all, promoting its clinical applications is the most important goal.

Pharmacokinetics and Tissue Distribution of DVDMS-2 in Tumor-bearing Mice

DVDMS-2 is a novel candidate for photodynamic therapy of tumors. The purpose of the present study was to assess the distribution and elimination of DVDMS-2 in mice bearing hepatoma 22 tumors. DVDMS-2 (1, 2 and 4 mg kg^-1 ) was injected intravenously into the mice, extracted from biological tissues and quantified using a fluorescence assay. The data obtained were processed with WinNonlin pharmacokinetic software. The fluorescence assay established for DVDMS-2 quantification was a rapid, reproducible, sensitive and specific method with good linearity. The pharmacokinetics of DVDMS-2 in tumor-bearing mice conformed to a two-compartment model. DVDMS-2 accumulated in tumor tissue to a greater extent than adjacent tissues (skin, muscle) and sustained a relatively high-level concentration 12 to 24 h following administration, which may be the optimal treatment time point. In conclusion, DVDMS-2 selectively accumulated in tumor tissue and was eliminated at a rapid rate in tumor-bearing mice, suggesting that DVDMS-2 may have few side effects, including skin phototoxicity. The present study established the pharmacokinetic characteristics of DVDMS-2, which may be beneficial in future clinical study.

Focused ultrasound-augmented targeting delivery of nanosonosensitizers from homogenous exosomes for enhanced sonodynamic cancer therapy

Sonodynamic therapy (SDT), wherein focused ultrasound is used to guide the site-specific delivery of nano-sonosensitizers and trigger profound sono-damage, has great potential in cancer theranostics. The development of nanosensitizers with high sono-activatable efficiency and good biosafety is however challenging.

Methods: In this study, we designed a functionalized smart nanosonosensitizer (EXO-DVDMS) by loading sinoporphyrin sodium (DVDMS), an excellent porphyrin sensitizer with both potential therapeutic and imaging applications, onto homotypic tumor cell-derived exosomes. Because of the high binding-affinity between DVDMS and proteins, coincubation of DVDMS and exosome would result in DVDMS attached on the surface or loaded in the core of exosomes. The prepared EXO-DVDMS was applied for ultrasound-responsive controlled release and enhanced SDT.

Results: Tumor cell-derived exosomes exhibited high stability and specificity towards the homotypic tumors, along with highly controlled ultrasound-responsive drug release, and boosted reactive oxygen species (ROS) generation to augment SDT. Intriguingly, EXO-DVDMS was endocytosed by lysosomes, and the low pH in the latter triggered DVDMS relocation synergistically with the ultrasound, thereby initiating multiple cell death-signaling pathways. Furthermore, the exosomal formulation served as a functionalized nanostructure, and facilitated simultaneous imaging and tumor metastasis inhibition, that were respectively 3-folds and 10-folds higher than that of free form.

Conclusions: Taken together, our findings suggest that an extracorporeal ultrasound device can non-invasively enhance homogenous tumor targeting and SDT toxicity of EXO-DVDMS, and the developed endogenous nano-sonosensitizer is a promising nanoplatform for activated cancer theranostics.

Synthesis and evolution of S-Porphin sodium as a potential antitumor agent for photodynamic therapy against breast cancer

The novel sensitizer S-Porphin sodium can generate ROS by radiation with a long wavelength to cause tumor cell death.

Apoptosis and autophagy induced by DVDMs-PDT on human esophageal cancer Eca-109 cells

BACKGROUND

Esophageal cancer is a common gastrointestinal cancer. About 300,000 people die from esophageal cancer every year in the world. Photodynamic therapy (PDT) has attracted attention as a feasible cancer therap for this diagnosis. Sinoporphyrin sodium (DVDMs) is a novel sensitizer isolated from photofrin. In this study, we aimed to investigate the effects of DVDMs mediated photodynamic therapy and the possible mechanism on human esophageal cancer Eca-109 cells.

METHODS

Cell viability was measured by MTT assay and cell apoptosis was determined by Annexin V-PE/7-AAD and western blot. MDC staining and western blot were used to evaluate cell autophagy. The production of intracellular reactive oxygen species (ROS) was detected by flow cytometry. The expression of MAPK and HO-1 were detected by western blot.

RESULTS

DVDMs-PDT decreased cell viability and induced cell apoptosis and autophagy. Autophagy inhibition reduced cell apoptosis triggered by DVDMs-PDT in Eca-109 cells. Generation of ROS was detected in DVDMs-PDT group. p38MAPK, JNK and HO-1 were activated after PDT treatment and the activation were reversed by adding ROS scavenger NAC.

CONCLUSIONS

Our studies demonstrated that DVDMs-PDT induced apoptosis and autophagy in Eca-109 cells. DVDMs-PDT induced ROS generation in Eca-109 cells, and the generation of ROS activated p38MAPK and JNK. Activation of p38MAPK and JNK may be involved in PDT-induced apoptosis.

808nm light triggered black TiO2 nanoparticles for killing of bladder cancer cells

The black TiO₂ nanoparticles are synthesized via a facile calcination method combined with an in-situ controllable solid-state reaction approach. The results indicate that the photocatalyst with a narrow band gap of ~2.32 eV extends the photoresponse to visible light and near infrared region. And thus more reactive oxygen species can be obtained to induce the cell-killing under 808 nm light triggering. The as-obtained black TiO₂ nanoparticles exhibiting low toxicity, good biocompatibility and high anticancer effect in vitro, is demonstrated as efficient photosensitizers for phototherapy to kill the bladder cancer cells. These findings suggest that the facile synthetic black TiO₂ nanomaterials will have broad application in biomedicine.

Selective photocytotoxicity of anthrols on cancer stem-like cells: The effect of quinone methides or reactive oxygen species

Cancer stem cells (CSCs) are a subpopulation of cancer cells that share properties of embryonic stem cells like pluripotency and self-renewal and show increased resistance to chemo- and radiotherapy. Targeting CSC, rather than cancer cells in general, is a novel and promising strategy for cancer treatment. Novel therapeutic approaches, such as photodynamic therapy (PDT) have been investigated. A promising group of phototherapeutic agents are reactive intermediates - quinone methides (QMs). This study describes preparation of QM precursor, 2-hydroxy-3-hydroxymethylanthracene (2) and a detailed photochemical and photobiological investigation on similar anthracene derivatives 3 and 4. Upon photoexcitation with near visible light at λ > 400 nm 1 and 2 give QMs, that were detected by laser flash photolysis and their reactivity with nucleophiles has been demonstrated in the preparative irradiation experiments where the corresponding adducts were isolated and characterized. 3 and 4 cannot undergo photodehydration and deliver QM, but lead to the formation of phenoxyl radical and singlet oxygen, respectively. The activity of 1-4 was tested on a panel of human tumor cell lines, while special attention was devoted to demonstrate their potential selectivity towards the cells with CSC-like properties (HMLEshEcad). Upon the irradiation of cell lines treated with 1-4, an enhancement of antiproliferative activity was demonstrated, but the DNA was not the target molecule. Confocal microscopy revealed that these compounds entered the cell and, upon irradiation, reacted with cellular membranes. Our experiments demonstrated moderate selectivity of 2 and 4 towards CSC-like cells, while necrosis was shown to be a dominant cell death mechanism. Especially interesting was the selectivity of 4 that produced higher levels of ROS in CSC-like cells, which forms the basis for further research on cancer phototherapy, as well as for the elucidation of the underlying mechanism of the observed CSC selectivity based on oxidative stress activation.