Unmodified Rose Bengal photosensitizer conjugated with NaYF4:Yb,Er upconverting nanoparticles for efficient photodynamic therapy

Photodynamic Treatment of Human Breast and Prostate Cancer Cells Using Rose Bengal-Encapsulated Nanoparticles

Cancer, a prominent cause of death, presents treatment challenges, including high dosage requirements, drug resistance, poor tumour penetration and systemic toxicity in traditional chemotherapy. Photodynamic therapy, using photosensitizers like rose bengal (RB) with a green laser, shows promise against breast cancer cells in vitro. However, the hydrophilic RB struggles to efficiently penetrate the tumour site due to the unique clinical microenvironment, aggregating around rather than entering cancer cells. In this study, we have synthesized and characterized RB-encapsulated chitosan nanoparticles with a peak particle size of ~200 nm. These nanoparticles are readily internalized by cells and, in combination with a green laser (λ = 532 nm) killed 94-98% of cultured human breast cancer cells (MCF-7) and prostate cancer cells (PC3) at a low dosage (25 μg/mL RB-nanoparticles, fluence ~126 J/cm2, and irradiance ~0.21 W/cm2). Furthermore, these nanoparticles are not toxic to cultured human normal breast cells (MCF10A), which opens an avenue for translational applications.

Targeting Tumor Microenvironment by Metal Peroxide Nanoparticles in Cancer Therapy

Solid tumors have a unique tumor microenvironment (TME), which includes hypoxia, low acidity, and high hydrogen peroxide and glutathione (GSH) levels, among others. These unique factors, which offer favourable microenvironments and nourishment for tumor development and spread, also serve as a gateway for specific and successful cancer therapies. A good example is metal peroxide structures which have been synthesized and utilized to enhance oxygen supply and they have shown great promise in the alleviation of hypoxia. In a hypoxic environment, certain oxygen-dependent treatments such as photodynamic therapy and radiotherapy fail to respond and therefore modulating the hypoxic tumor microenvironment has been found to enhance the antitumor impact of certain drugs. Under acidic environments, the hydrogen peroxide produced by the reaction of metal peroxides with water not only induces oxidative stress but also produces additional oxygen. This is achieved since hydrogen peroxide acts as a reactive substrate for molecules such as catalyse enzymes, alleviating tumor hypoxia observed in the tumor microenvironment. Metal ions released in the process can also offer distinct bioactivity in their own right. Metal peroxides used in anticancer therapy are a rapidly evolving field, and there is good evidence that they are a good option for regulating the tumor microenvironment in cancer therapy. In this regard, the synthesis and mechanisms behind the successful application of metal peroxides to specifically target the tumor microenvironment are highlighted in this review. Various characteristics of TME such as angiogenesis, inflammation, hypoxia, acidity levels, and metal ion homeostasis are addressed in this regard, together with certain forms of synergistic combination treatments.

Importance of Rose Bengal Loaded with Nanoparticles for Anti-Cancer Photodynamic Therapy

Rose Bengal (RB) is a photosensitizer (PS) used in anti-cancer and anti-bacterial photodynamic therapy (PDT). The specific excitation of this PS allows the production of singlet oxygen and oxygen reactive species that kill bacteria and tumor cells. In this review, we summarize the history of the use of RB as a PS coupled by chemical or physical means to nanoparticles (NPs). The studies are divided into PDT and PDT excited by X-rays (X-PDT), and subdivided on the basis of NP type. On the basis of the papers examined, it can be noted that RB used as a PS shows remarkable cytotoxicity under the effect of light, and RB loaded onto NPs is an excellent candidate for nanomedical applications in PDT and X-PDT.

One-Pot Synthesis Bodipy Nano-Precipitations for Prostate Cancer Treatment

Here in this study, we proposed a polystyrene maleic anhydride (PSMA) stabilized Bodipy nanoparticles (PB NPs) in a one-pot approach for the photodynamic therapy (PDT) of prostate cancer. The nanoparticle formed by precipitation method was then employed to treat PC-3 cells and PC-3 tumor bearing nude mice model. It was shown that this platform showed promising anticancer performance than free bodipy with reduced side effects.

Phenylboronic Acid Modification Augments the Lysosome Escape and Antitumor Efficacy of a Cylindrical Polymer Brush-Based Prodrug

Timely lysosome escape is of paramount importance for endocytosed nanomedicines to avoid premature degradation under the acidic and hydrolytic conditions in lysosomes. Herein, we report an exciting finding that phenylboronic acid (PBA) modification can greatly facilitate the lysosome escape of cylindrical polymer brushes (CPBs). On the basis of our experimental results, we speculate that the mechanism is associated with the specific interactions of the PBA groups with lysosomal membrane proteins and hot shock proteins. The featured advantage of the PBA modification over the known lysosome escape strategies is that it does not cause significant adverse effects on the properties of the CPBs; on the contrary, it enhances remarkably their tumor accumulation and penetration. Furthermore, doxorubicin was conjugated to the PBA-modified CPBs with a drug loading content larger than 20%. This CPBs-based prodrug could eradicate the tumors established in mice by multiple intravenous administrations. This work provides a novel strategy for facilitating the lysosome escape of nanomaterials and demonstrates that PBA modification is an effective way to improve the overall properties of nanomedicines including the tumor therapeutic efficacy.

The role of photodynamic therapy in breast cancer - A review of in vitro research

Breast cancer is the most common cancer affecting women and the incidence of occurrence is increasing. Currently, there are many methods of detecting and treating breast cancer. Some treatments have a number of side effects. Photodynamic therapy (PDT) is a minimally invasive method of treatment which uses monochromatic light of low to medium energy to excite previously applied photosensitizers (PS) for ROS production. The purpose of this article is to present a general overview of the use of PDT in in vitro studies of various cancer cell lines. A literature search for articles corresponding to the topic of this review was performed using the PubMed and Scopus databases using the following keywords: 'photodynamic therapy', 'breast cancer', and 'photosensitizer(s).' Much of the reviewed literature is based on evaluations of the cytotoxic potential of various PSs, particularly against the MCF-7 cell line, and enhancement of PDT potential with nanotechnology. Research on photodynamic effects in vitro may be helpful in the pre-clinical search for optimal methods for in vivo clinical treatment.

One-pot synthesis chlorin e6 nano-precipitation for colorectal cancer treatment Ce6 NPs for colorectal cancer treatment

The drug nanoparticles free of additional carriers hold great promise in drug delivery and are suitable for the therapy of cancers. Herein, we developed a one-pot method to prepare chlorin e6 (Ce6) nano-precipitations (Ce6 NPs) for effective photodynamic therapy of colorectal cancer. The drug loading of Ce6 NPs was around 81% and showed acceptable stability, high biocompatibility as well as effective reactive oxygen species (ROS) generation capability. As a result, the Ce6 NPs can produce significantly elevated ROS upon laser irradiations and achieved better anticancer benefits than free Ce6.

Light Technology for Efficient and Effective Photodynamic Therapy: A Critical Review

Photodynamic therapy (PDT) is a cancer treatment with strong potential over well-established standard therapies in certain cases. Non-ionising radiation, localisation, possible repeated treatments, and stimulation of immunological response are some of the main beneficial features of PDT. Despite the great potential, its application remains challenging. Limited light penetration depth, non-ideal photosensitisers, complex dosimetry, and complicated implementations in the clinic are some limiting factors hindering the extended use of PDT. To surpass actual technological paradigms, radically new sources, light-based devices, advanced photosensitisers, measurement devices, and innovative application strategies are under extensive investigation. The main aim of this review is to highlight the advantages/pitfalls, technical challenges and opportunities of PDT, with a focus on technologies for light activation of photosensitisers, such as light sources, delivery devices, and systems. In this vein, a broad overview of the current status of superficial, interstitial, and deep PDT modalities-and a critical review of light sources and their effects on the PDT process-are presented. Insight into the technical advancements and remaining challenges of optical sources and light devices is provided from a physical and bioengineering perspective.

Photosensitizer-Functionalized Nanocomposites for Light-Activated Cancer Theranostics

Photosensitizers (PSs) have received significant attention recently in cancer treatment due to its theranostic capability for imaging and phototherapy. These PSs are highly responsive to light source of a suitable wavelength for image-guided cancer therapy from generated singlet oxygen and/or thermal heat. Various organic dye PSs show tremendous attenuation of tumor cells during cancer treatment. Among them, porphyrin and chlorophyll-based ultraviolet-visible (UV-Vis) dyes are employed for photodynamic therapy (PDT) by reactive oxygen species (ROS) and free radicals generated with 400-700 nm laser lights, which have poor tissue penetration depth. To enhance the efficacy of PDT, other light sources such as red light laser and X-ray have been suggested; nonetheless, it is still a challenging task to improve the light penetration depth for deep tumor treatment. To overcome this deficiency, near infrared (NIR) (700-900 nm) PSs, indocyanine green (ICG), and its derivatives like IR780, IR806 and IR820, have been introduced for imaging and phototherapy. These NIR PSs have been used in various cancer treatment modality by combining photothermal therapy (PTT) and/or PDT with chemotherapy or immunotherapy. In this review, we will focus on the use of different PSs showing photothermal/photodynamic response to UV-Vis or NIR-Vis light. The emphasis is a comprehensive review of recent smart design of PS-loaded nanocomposites for targeted delivery of PSs in light-activated combination cancer therapy.

Dual Antibacterial Effect of In Situ Electrospun Curcumin Composite Nanofibers to Sterilize Drug-Resistant Bacteria

Bacterial infection especially caused by multidrug-resistant bacteria still endangers human life. Photodynamic therapy (PDT) can effectively kill bacteria, and nanofiber-based PDT can effectively reduce damage to normal tissues. However, current photosensitizers coated on the surfaces of fibers would release to the wound, causing some side effects. And nanofibers prepared by traditional method exhibit poor adhesion on the wound, which severely reduces the PDT effect due to its short-range effect. Herein, core-shell curcumin composite nanofibers are prepared by in situ electrospinning method via a self-made portable electrospinning device. The obtained composite nanofibers show superior adhesiveness on different biological surface than that of traditional preparation method. Upon 808-nm irradiation, these composite nanofibers effectively produced singlet oxygen (1O2) without curcumin falling off. After these composite nanofibers' exposure to drug-resistant bacteria, they exhibit dual antibacterial behaviors and efficiently kill the drug-resistant bacteria. These dual antibacterial nanofiber membranes with excellent adhesiveness may benefit the application of wound infection as antibacterial dressing.

NIR Photoregulated Theranostic System Based on Hexagonal-Phase Upconverting Nanoparticles for Tumor-Targeted Photodynamic Therapy and Fluorescence Imaging

Although photodynamic therapy (PDT) is an effective, minimally invasive therapeutic modality with advantages in highly localized and specific tumor treatments, large and deep-seated cancers within the body cannot be successfully treated due to low transparency to visible light. To improve the therapeutic efficiency of tumor treatment in deep tissue and reduce the side effects in normal tissue, this study developed a near-infrared (NIR)-triggered upconversion nanoparticle (UCNP)-based photosensitizer (PS) carrier as a new theranostics system. The NaYF4:Yb/Er UCNPs were synthesized by a hydrothermal method, producing nanoparticles of a uniformly small size (≈20 nm) and crystalline morphology of the hexagonal phase. These UCNPs were modified with folic acid-conjugated biocompatible block copolymers through a bidentate dihydrolipoic acid linker. The polymer modified hexagonal phase UCNPs (FA-PEAH-UCNPs) showed an improved dispersibility in the aqueous solution and strong NIR-to-vis upconversion fluorescence. The hydrophobic PS, pheophorbide a (Pha), was then conjugated to the stable vectors. Moreover, these UCNP-based Pha carriers containing tumor targeting folic acid ligands exhibited the significantly enhanced cellular uptake efficiency as well as PDT treatment efficiency. These results suggested that this system could extend the excitation wavelength of PDT to the NIR region and effectively improve therapeutic efficiency of PSs.