Targeted photodynamic therapy technique of Janus nanoparticles on breast cancer.

Spherical gold/polyacrylic acid (Au/PAA) polymer-inorganic Janus nanoparticles (JNPs) with simultaneous therapeutic and targeting functions were fabricated. The obtained Au/PAA JNPs were further selectively functionalized with folic acid (FA) and thiol PEG amine (SH-PEG-NH2) on Au sides to provide superior biocompatibility and active targeting, while the other PAA sides were loaded with 5-aminolevulinic acid (5-ALA) to serve as a photosensitizer (PS) for photodynamic therapeutic (PDT) effects on MCF-7 cancer cells. The PS loading of 5-ALA was found to be 83% with an average hydrodynamic size and z-potential of 146 ± 0.8 nm and -6.40 mV respectively for FA-Au/PAA-ALA JNPs. The in vitro PDT study of the JNPs on MCF-7 breast cancer cells under 636 nm laser irradiation indicated the cell viability of 24.7% ± 0.5 for FA-Au/PAA-ALA JNPs at the IC50 value of 0.125 mM. In this regard, the actively targeted FA-Au/PAA-ALA JNPs treatment holds great potential for tumour therapy with high cancer cell-killing efficacy.

Photodynamic Therapy-Mediated Immune Responses in Three-Dimensional Tumor Models.

Photodynamic therapy (PDT) is a promising non-invasive phototherapeutic approach for cancer therapy that can eliminate local tumor cells and produce systemic antitumor immune responses. In recent years, significant efforts have been made in developing strategies to further investigate the immune mechanisms triggered by PDT. The majority of in vitro experimental models still rely on the two-dimensional (2D) cell cultures that do not mimic a three-dimensional (3D) cellular environment in the human body, such as cellular heterogeneity, nutrient gradient, growth mechanisms, and the interaction between cells as well as the extracellular matrix (ECM) and therapeutic resistance to anticancer treatments. In addition, in vivo animal studies are highly expensive and time consuming, which may also show physiological discrepancies between animals and humans. In this sense, there is growing interest in the utilization of 3D tumor models, since they precisely mimic different features of solid tumors. This review summarizes the characteristics and techniques for 3D tumor model generation. Furthermore, we provide an overview of innate and adaptive immune responses induced by PDT in several in vitro and in vivo tumor models. Future perspectives are highlighted for further enhancing PDT immune responses as well as ideal experimental models for antitumor immune response studies.

Targeted Photodynamic Therapy Using Alloyed Nanoparticle-Conjugated 5-Aminolevulinic Acid for Breast Cancer.

Photodynamic therapy (PDT) has been investigated as an effective, non-invasive, and alternative tumor-ablative therapy that uses photosensitizers (PSs) and safe irradiation light in the presence of oxygen to generate reactive oxygen species (ROS) to kill malignant cancer cells. However, the off-target activation of the PSs can hinder effective PDT. Therefore, an advanced drug delivery system is required to selectively deliver the PS to the therapeutic region only and reduce off-target side effects in cancer treatment. The integration of laser-initiated PDT with nanotechnology has provided new opportunities in cancer therapy. In this study, plasmonic bimetallic nanoparticles (NPs) were prepared for the targeted PDT (TPDT) of in vitro cultured MCF-7 breast cancer cells. The NPs were functionalized with PEG through Au-thiol linkage to enhance their biocompatibility and subsequently attached to the PS precursor 5-aminolevulinic acid via electrostatic interactions. In order to enhance specific targeting, anti-HER-2 antibodies (Ab) were decorated onto the surface of the nanoconjugate (NC) to fabricate a 5-ALA/Au-Ag-PEG-Ab NC. In vitro studies showed that the synthesized NC can enter MCF-7 cells and localize in the cytoplasm to metabolize 5-ALA to protoporphyrin IX (PpIX). Upon light irradiation, PpIX can efficiently produce ROS for the PDT treatment of MCF-7. Cellular viability studies showed a decrease from 49.8% ± 5.6 ** to 13.8% ± 2.0 *** for free 5-ALA versus the NC, respectively, under equivalent concentrations of the PS (0.5 mM, IC50). These results suggest that the active targeted NC platform has an improved PDT effect on MCF-7 breast cancer cells.

Fluorescence Sensing with Molecularly Imprinted Polymer-Capped Quantum Dots.

Procedures for the design of a fluorescence sensor based on molecularly imprinted polymer-capped quantum dots (MIP@QDs) together with the synthesis of quantum dots and MIP@QDS are described. Spherical and monodispersed nanoparticles are suitable for fluorescence sensing of an analyte such as pharmaceuticals and polycyclic aromatic hydrocarbons (PAHs). In addition, excellent optical properties, higher quantum yield, and photoluminescence efficiency as well as easy detection of emission spectra are distinctive advantages of quantum dots as fluorescence sensors. Optimization of different variables and analytical applications of the sensor are also presented, which are of value for fluorescence sensing.

Inorganic Nanoparticles Applied for Active Targeted Photodynamic Therapy of Breast Cancer.

Photodynamic therapy (PDT) is an alternative modality to conventional cancer treatment, whereby a specific wavelength of light is applied to a targeted tumor, which has either a photosensitizer or photochemotherapeutic agent localized within it. This light activates the photosensitizer in the presence of molecular oxygen to produce phototoxic species, which in turn obliterate cancer cells. The incidence rate of breast cancer (BC) is regularly growing among women, which are currently being treated with methods, such as chemotherapy, radiotherapy, and surgery. These conventional treatment methods are invasive and often produce unwanted side effects, whereas PDT is more specific and localized method of cancer treatment. The utilization of nanoparticles in PDT has shown great advantages compared to free photosensitizers in terms of solubility, early degradation, and biodistribution, as well as far more effective intercellular penetration and uptake in targeted cancer cells. This review gives an overview of the use of inorganic nanoparticles (NPs), including: gold, magnetic, carbon-based, ceramic, and up-conversion NPs, as well as quantum dots in PDT over the last 10 years (2009 to 2019), with a particular focus on the active targeting strategies for the PDT treatment of BC.

Review: Organic nanoparticle based active targeting for photodynamic therapy treatment of breast cancer cells.

Targeted Photodynamic therapy (TPDT) is a non-invasive and site-specific treatment modality, which has been utilized to eradicate cancer tumour cells with photoactivated chemicals or photosensitizers (PSs), in the presence of laser light irradiation and molecular tissue oxygen. Breast cancer is the commonest cancer among women worldwide and is currently treated using conventional methods such as chemotherapy, radiotherapy and surgery. Despite the recent advancements made in PDT, poor water solubility and non-specificity of PSs, often affect the overall effectivity of this unconventional cancer treatment. With respect to conventional PS obstacles, great strides have been made towards the application of targeted nanoparticles in PDT to resolve these limitations. Therefore, this review provides an overview of scientific peer reviewed published studies in relation to functionalized organic nanoparticles (NPs) for effective TPDT treatment of breast cancer over the last 10 years (2009 to 2019). The main aim of this review is to highlight the importance of organic NP active based PDT targeted drug delivery systems, to improve the overall biodistribution of PSs in breast cancer tumour's.

Recent Advances in Porphyrin-Based Inorganic Nanoparticles for Cancer Treatment.

The application of porphyrins and their derivatives have been investigated extensively over the past years for phototherapy cancer treatment. Phototherapeutic Porphyrins have the ability to generate high levels of reactive oxygen with a low dark toxicity and these properties have made them robust photosensitizing agents. In recent years, Porphyrins have been combined with various nanomaterials in order to improve their bio-distribution. These combinations allow for nanoparticles to enhance photodynamic therapy (PDT) cancer treatment and adding additional nanotheranostics (photothermal therapy-PTT) as well as enhance photodiagnosis (PDD) to the reaction. This review examines various porphyrin-based inorganic nanoparticles developed for phototherapy nanotheranostic cancer treatment over the last three years (2017 to 2020). Furthermore, current challenges in the development and future perspectives of porphyrin-based nanomedicines for cancer treatment are also highlighted.

A triclosan turn-ON fluorescence sensor based on thiol-capped core/shell quantum dots.

Triclosan (TCS) is a common antimicrobial found in many personal care products. A large amount of TCS thus enters the wastewater system leading to the accumulation thereof in water sources. In this work, core-shell structured GSH-CdSe/ZnS fluorescent quantum dots (QDs) were synthesized based on organometallic synthesis with a thiol ligand capping agent. The GSH-CdSe/ZnS QDs showed excellent photostability and a photoluminescence quantum yield of 89%. The fluorescence of the GSH-CdSe/ZnS QDs was enhanced by the introduction of TCS, likely owing to fluorescence resonance energy transfer from TCS to the QDs, allowing for its use as a "turn on" fluorescence probe for the detection and determination of TCS. A linear response was observed in the range of 10-300 nmol L-1 with limits of detection and quantification of 3.7 and 12.4 nmol L-1 respectively. The probe displayed good recoveries (94%-117.5%) for the determination of TCS in tap and river water samples which demonstrated the suitability of this novel sensor for a monitoring application of environmental relevance.