A novel nano-superparamagnetic agent for photodynamic and photothermal therapies: An in-vitro study

Molecular MR Imaging of Prostate Cancer by Specified Iron Oxide Nanoparticles With PSMA-11 Peptides: A Preclinical Study

BACKGROUND

Prostate-specific membrane antigen (PSMA) can provide a prostate cancer (PCa) detection approach in positron emission tomography (PET) using Food and Drug Administration (FDA)-approved PSMA-11 peptide. There are some studies evaluated magnetic-nanoprobes for PSMA detection by MRI, using non-FDA-approved ligands including antibodies or peptides, which are not as specific as PSMA-11.

PURPOSE

To assess targeted iron oxide nanoparticles (IONPs) by PSMA-11 peptides as a potential specific nano-molecular probes to investigate a PSMA+ PCa-xenograft model by MRI.

STUDY TYPE

Prospective.

ANIMAL MODEL

Twenty male C57BL6 nude mice induced subcutaneously PSMA+ LNCaP cell line tumor.

FIELD STRENGTH/SEQUENCE

1.5 T, T2-W Fast Spin echo and T2*-W Gradient echo.

ASSESSMENT

Coated IONPs with Carboxymethylated-dextran (DNPs) and with bovine serum albumin (BNPs), as well as, targeted DNPs with PSMA-11-HYNIC peptide (TDNPs) and targeted BNPs with PSMA-11-HBED peptide (TBNPs) were injected intravenously with dose 2.8 mg Fe/kg. Coronal T2-W and the T2*-W images were obtained before and 4 hours and 6 hours post-injection. Signal intensity (SI) and relative signal enhancement (RSE) were computed in two- and three-dimensional analyses. Histological analysis of tumors was evaluated, and the Fe distribution within the body based on atomic absorption spectroscopy was calculated.

STATISTICAL TESTS

One-way ANOVA followed by Tukey's multiple comparison test, Paired-samples T-test, P < 0.05 was considered significant.

RESULTS

A reduction in T2-W SI was achieved as 22 ± 7%, 59 ± 3%, 65 ± 5%, and 78 ± 3% respectively for BNPs, TBNPs, DNPs, and TDNPs 6 hours post-injection. The most difference between targeted and non-targeted groups was observed at 6 hours for PSMA-11-HBED, and at 4 hours for PSMA-11-HYNIC. RSE indicated 88.6 ± 3.1% and 80.7 ± 3.2% enhanced contrast between tumor and muscle region for TBNPs and TDNPs on T2*-W images.

CONCLUSIONS

Both TBNPs and TDNPs are promising novel nano-molecular probes for PSMA+ PCa tumor detection. The injection dose of non-targeted IONPs can be reduced by using targeted nanoprobes three times for BNPs and two times for DNPs.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 1.

Hyphae-specific genes: Possible molecular targets for magnetic iron oxide nanoparticles alone and combined with visible light in Candida albicans

Candida albicans readily develops resistance to fluconazole. Magnetic iron oxide nanoparticles (denoted as MION) and antimicrobial photodynamic therapy are attracting attention as therapeutic agents. This study aims to investigate the inhibitory efficacy of MION alone and combined with visible light against C. albicans and expression analysis of hyphal wall protein 1 (HWP1) and agglutinin-like sequence 1 (ALS1) genes in C. albicans. Antifungal susceptibility testing, photodynamic activity assay, reactive oxygen species (ROS) production assay and gene expression analysis were determined in C. albicans treated with MION alone and combined with visible light. MION at 1 × minimum inhibitory concentration (MIC) level (500 μg/mL) exhibited antifungal activity against C. albicans isolates. Further, 1 × MIC levels of MION alone and combined with visible light displayed remarkable fungicidal effects at 24 and 48 h after treatment. The MION combined with visible light caused the highest levels of ROS production by all C. albicans isolates. The relative RT-PCR data showed significant downregulation of HWP1 and ALS1 genes which are the key virulence genes in C. albicans. Differences in gene expression of  HWP1 and ALS1 were more significant in MION combined with visible light treatments than MION alone. Our study sheds a novel light on facile development of effective treatment of C. albicans especially fluconazole-resistant C. albicans infections. The hyphae-specific genes HWP1 and ALS1 could be probable molecular targets for MION alone and combined with visible light in C. albicans.

Exploring the Role of Phytochemicals as Potent Natural Photosensitizers in Photodynamic Therapy

BACKGROUND

Cancer is still considered a deadly disease worldwide due to difficulties in diagnosis, painful treatment procedures, costly therapies, side effects, and cancer relapse. Cancer treatments using conventional methods like chemotherapy and radiotherapy were not convincing due to its post-treatment toxicity in the host. In Photodynamic Therapy (PDT), three individual non-toxic components including a photosensitizer, light source and oxygen cause damage to the cells and tissues when they are combined.

OBJECTIVE

In recent years, phytochemicals are being increasingly recognized as potent complementary drugs for cancer because of its natural availability, less toxicity and therapeutic efficiency in par with commercial drugs. Hence, the idea of using phytochemicals as natural photosensitizers in PDT resulted in a multiple pool of research studies with promising results in preclinical and clinical investigations.

METHODS

In this review, the potential of phytochemicals to act as natural photosensitizers for PDT, their mode of action, drawbacks, challenges and possible solutions are discussed in detail.

RESULTS

In PDT, natural photosensitizers, when used alone or in combination with other photosensitizers, induced cell death by apoptosis and necrosis, increased oxidative stress, altered cancer cell death signaling pathways, increased cytotoxicity and DNA damage in cancer cells. The pro-oxidant nature of certain antioxidant polyphenols, hormesis phenomenon, Warburg effect and DNA damaging potential plays a significant role in the photosensitizing mechanism of phytochemicals in PDT.

CONCLUSION

This review explores the role of phytochemicals that can act as photosensitizers alone or in combination with PDT and its mechanism of action on different cancers.

Smart Responsive Nanoformulation for Targeted Delivery of Active Compounds From Traditional Chinese Medicine

Traditional Chinese medicine (TCM) has been used to treat disorders in China for ~1,000 years. Growing evidence has shown that the active ingredients from TCM have antibacterial, antiproliferative, antioxidant, and apoptosis-inducing features. However, poor solubility and low bioavailability limit clinical application of active compounds from TCM. “Nanoformulations” (NFs) are novel and advanced drug-delivery systems. They show promise for improving the solubility and bioavailability of drugs. In particular, “smart responsive NFs” can respond to the special external and internal stimuli in targeted sites to release loaded drugs, which enables them to control the release of drug within target tissues. Recent studies have demonstrated that smart responsive NFs can achieve targeted release of active compounds from TCM at disease sites to increase their concentrations in diseased tissues and reduce the number of adverse effects. Here, we review “internal stimulus–responsive NFs” (based on pH and redox status) and “external stimulus–responsive NFs” (based on light and magnetic fields) and focus on their application for active compounds from TCM against tumors and infectious diseases, to further boost the development of TCM in modern medicine.

Ag2S-Glutathione quantum dots for NIR image guided photothermal therapy

Synthesis of ultrasmall, colloidally stable, biocompatible Ag₂S-gluthatione quantum dots for NIR image guided-long wavelength photothermal therapy agents.

Indocyanine green loaded APTMS coated SPIONs for dual phototherapy of cancer

Superparamagnetic iron oxide nanoparticles (SPIONs) have been recently recognized as highly efficient photothermal therapy (PTT) agents. Here, we demonstrate, for the first time to our knowledge, dose and laser intensity dependent PTT potential of small, spherical, 3-aminopropyltrimethoxysilane coated cationic superparamagnetic iron oxide nanoparticles (APTMS@SPIONs) in aqueous solutions upon irradiation at 795 nm. Indocyanine green (ICG) which has been recently used for photodynamic therapy (PDT), was loaded to APTMS@SPIONs to improve the stability of ICG and to achieve an effective mild PTT and PDT (dual therapy) combination for synergistic therapeutic effect on cancer cells via a single laser treatment in the near infrared (NIR). Neither APTMS@SPIONs nor ICG-APTMS@SPIONs showed dark toxicity on MCF7 breast and HT29 colon cancer cell lines. A safe laser procedure was determined as 10 min irradiation at 795 nm with 1.8 W/cm² of laser intensity, at which APTMS@SPION did not cause a significant cell death. However, free ICG reduced cell viability at and above 10 μg/ml under these conditions along with generation of reactive oxygen species (ROS), more effectively in MCF7. ICG-APTMS@SPION treated cells showed 2-fold increase in ROS generation and near complete cell death at and below 5 μg/ml ICG dose, even in less sensitive HT29 cells after a single laser treatment at NIR, which would be safe for the healthy tissue and provide a longer penetration depth. Besides, both components can be utilized for diagnosis and the overall composition may be used for optical-image guided phototherapy in the NIR region.