Photosensitizer-assembled PEGylated graphene-copper sulfide nanohybrids as a synergistic near-infrared phototherapeutic agent

Objectives: Stimulative nanostructures play a crucial role in developing the smart nanomedicine for high therapeutic efficacy with minimum adverse effects. Herein, a near-infrared (NIR) light-responsive nanohybrids p-nanographene oxide (GO)-copper sulfide (CuS)/indocyanine green (ICG) comprised of GO, CuS nanoparticles and photosensitizer ICG was fabricated to couple the photothermal property of CuS and photodynamic effect of ICG in one system in order to achieve the synergistic phototherapy.

Methods: pGO-CuS/ICG was constructed by self-assembling ICG on pGO-CuS nanostructure. Its physicochemical, photothermal and photodynamic properties were studied by spectroscopic methods. The in vitro cellular uptake, cytotoxicity, the single/combined photothermal therapeutic (PTT) and photodynamic therapeutic (PDT) effects were investigated with biological techniques.

Results: pGO-CuS/ICG exhibited high efficacy of photothermal conversation and singlet oxygen generation under NIR laser excitation. It entered into the target cancer cells probably via passive transmembrane pathway and exerted obvious PTT and PDT effect against the tumor cells upon irradiation with the respective 940 and 808 nm lasers. In particular, the tremendous synergistic efficacy of PDT and PTT had been demonstrated by tuning the NIR laser combined irradiation.

Conclusions: This study promises the future applications of pGO-CuS/ICG as a NIR light activable theranostic nanodrug for deep-seated cancer noninvasive phototherapy.     

New-generation photosensitizer-anchored gold nanorods for a single near-infrared light-triggered targeted photodynamic–photothermal therapy

Traditional combined photodynamic and photothermal therapy (PDT/PTT) was limited in clinical treatment of cancer due to the exceptionally low drug delivery efficiency to tumor sites and the activation by laser excitation with different wavelengths. We have accidentally discovered that our synthesized chlorin e6-C-15-ethyl ester (HB, a new type of photosensitizer) be activated by a laser with an excitation wavelength of 660 nm. Herein, we utilized Au nanorods (AuNRs) as 660 nm-activated PTT carriers to be successively surface-functionalized with HB and tumor-targeting peptide cyclic RGD (cRGD) to develop HB-AuNRs@cRGD for single NIR laser-induced targeted PDT/PTT. The HB-AuNRs@cRGD could be preferentially accumulated within tumor sites and rapidly internalized by cancer cells. Thereby, the HB-AuNRs@cRGD could exhibit amplified therapeutic effects by producing both significant reactive oxygen species (ROS) and hyperthermia simultaneously under the guidance of fluorescence imaging. The tumor inhibition rate on ECA109 esophageal cancer model was approximately 77.04%, and the negligible systematic toxicity was observed. This study proposed that HB-AuNRs@cRGD might be a promising strategy for single NIR laser-induced and imaging-guided targeted bimodal phototherapy.     

Inorganic nanoparticles for enhanced photodynamic cancer therapy

Photodynamic therapy (PDT) in cancer treatment uses photosensitizers to generate singlet oxygen followed by photoirradiation. The efficacy of PDT is greatly determined by the dosimetry of activation light and the photosensitizer (PS), modulating the photodynamic reaction at depth in diseased tissue. Development of nano-formulated photosensitizer has emerged as a promising field because of the biocompatibility and the accessibility for multi-functionalization of nanoparticles. In this review, we summarize the contemporary progress in use of inorganic nanoparticles for improvement of PDT in cancer therapeutics.     

Singlet oxygen-induced apoptosis of cancer cells using upconversion fluorescent nanoparticles as a carrier of photosensitizer

The photodynamic effect of upconversion nanoparticles loaded with a photosensitizer was studied on murine bladder cancer cells (MB49). Mesoporous silica was coated onto sodium yttrium fluoride upconversion nanocrystals to form a core-shell structure and then loaded with the photosensitizer zinc (II)-phthalocyanine into the porous silica. The nanoparticles displayed a uniform spherical shape with an average diameter of about 50 nm and showed good dispersibility in water. Intracellular uptake study in MB49 cells revealed a time- and concentration-dependent accumulation of these nanoparticles. Upon irradiation with 980-nm near-infrared light, their efficiency in activating the loaded zinc (II)-phthalocyanine to generate singlet oxygen molecules was confirmed in live cells. The cytotoxic effect of the released singlet oxygen from the nanoplatform was proven by cell viability assay, confocal microscopy, DNA agarose gel electrophoresis, cytochrome c–releasing assay, and prostate-specific antigen–enzyme-linked immunosorbent assay, all of which showed a strong photodynamic effect of the nanoparticles on MB49 cells. This suggests the efficacy of sodium yttrium fluoride upconversion nanoparticles as a carrier for photosensitizers and their use in photodynamic therapy of cancer and some other diseases.From the Clinical EditorIn this study, the photodynamic effect of upconversion nanoparticles loaded with a photosensitizer was investigated on murine bladder cancer cells, with strongly positive results, which may pave its way to future clinical use in malignant tumors and potentially other diseases.     

Phthalocyanines covalently bound to biomolecules for a targeted photodynamic therapy

Photodynamic therapy (PDT) is a relatively new cytotoxic treatment, predominantly used in anticancer approaches, that depends on the retention of photosensitizers in tumor and their activation after light exposure. This technology is based on the light excitation of a photosensitizer which induces very localized oxidative damages within the cells by formation of highly reactive oxygen species, the most important being singlet oxygen. Many photo-activable molecules have been synthesized such as porphyrins, chlorins and more recently phthalocyanines which present a strong light absorption at wavelengths around 670 nm and are therefore well-adapted to the optical window required for PDT application. However, the lack of selective accumulation of these photo-activable molecules within tumor tissue is a major problem in PDT, and one research area of importance is developing targeted photosensitizers. Indeed, targeted photodynamic therapy offers the advantage to enhance photodynamic efficiency by directly targeting diseased cells or tissues. Many attempts have been made to either increase the uptake of the dye by the target cells and tissues or to improve subcellular localization so as to deliver the dye to photosensitive sites within the cells. The aim of this review is to present the actual state of the development of phthalocyanines covalently conjugated with biomolecules that possess a marked selectivity towards cancer cells; for some of them their photophysical properties and photodynamic activity will be presented.     

Synchronous delivery of oxygen and photosensitizer for alleviation of hypoxia tumor microenvironment and dramatically enhanced photodynamic therapy

Photosensitizer, proper laser irradiation, and oxygen are essential components for effective photodynamic therapy (PDT) in clinical cancer therapy. However, native hypoxic tumoral microenvironment is a major barrier hindering photodynamic reactions in vivo. Thus, we have prepared biocompatible liposomes by loading complexes of oxygen-carrier (hemoglobin, Hb) and photosensitizer (indocyanine green, ICG) for enhanced PDT against hypoxic tumor. Ideal oxygen donor Hb, which is an oxygen-carried protein in red blood cells, makes such liposome which provide stable oxygen supply. ICG, as a photosensitizer, could transfer energy from lasers to oxygen to generate cytotoxic reactive oxygen species (ROS) for treatment. The liposomes loading ICG and Hb (LIH) exhibited efficient tumor homing upon intravenous injection. As revealed by T₂-weighted magnetic resonance imaging and immunohistochemical analysis, the intratumoral hypoxia was greatly alleviated, and the level of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in tumor was obviously down-regulated. A weak PDT efficiency was found in cells incubated in simulated hypoxia condition in vitro, while PDT effect was dramatically enhanced in LIH treated hypoxia cells under near-infrared (NIR) laser, which was mainly attributed to massive generation of ROS with sufficient oxygen supply. ROS trigger oxidative damage of tumors and induce complete suppression of tumor growth and 100% survival rate of mice, which were also in good health condition. Our work highlights a liposome-based nanomedicine that could effectively deliver oxygen to tumor and alleviate tumor hypoxia state, inducing greatly improved efficacy compared to conventional cancer PDT and demonstrates the promise of modulating unfavorable tumor microenvironment with nanotechnology to overcome limitations of cancer therapies.     

TSPO 18 kDa (PBR) Targeted Photosensitizers for Cancer Imaging (PET) and PDT

相似文献   

Development of redox-responsive theranostic nanoparticles for near-infrared fluorescence imaging-guided photodynamic/chemotherapy of tumor

The development of imaging-guided smart drug delivery systems for combinational photodynamic/chemotherapy of the tumor has become highly demanded in oncology. Herein, redox-responsive theranostic polymeric nanoparticles (NPs) were fabricated innovatively using low molecular weight heparin (LWMH) as the backbone. Chlorin e6 (Ce6) and alpha-tocopherol succinate (TOS) were conjugated to LMWH via cystamine as the redox-sensitive linker, forming amphiphilic Ce6-LMWH-TOS (CHT) polymer, which could self-assemble into NPs in water and encapsulate paclitaxel (PTX) inside the inner core (PTX/CHT NPs). The enhanced near-infrared (NIR) fluorescence intensity and reactive oxygen species (ROS) generation of Ce6 were observed in a reductive environment, suggesting the cystamine-switched “ON/OFF” of Ce6. Also, the in vitro release of PTX exhibited a redox-triggered profile. MCF-7 cells showed a dramatically higher uptake of Ce6 delivered by CHT NPs compared with free Ce6. The improved therapeutic effect of PTX/CHT NPs compared with mono-photodynamic or mono-chemotherapy was observed in vitro via MTT and apoptosis assays. Also, the PTX/CHT NPs exhibited a significantly better in anti-tumor efficiency upon NIR irradiation according to the results of in vivo combination therapy conducted on 4T1-tumor-bearing mice. The in vivo NIR fluorescence capacity of CHT NPs was also evaluated in tumor-bearing nude mice, implying that the CHT NPs could enhance the accumulation and retention of Ce6 in tumor foci compared with free Ce6. Interestingly, the anti-metastasis activity of CHT NPs was observed against MCF-7 cells by a wound healing assay, which was comparable to LMWH, suggesting LMWH was promising for construction of nanocarriers for cancer management.     

Pyropheophorbide A and c(RGDyK) comodified chitosan-wrapped upconversion nanoparticle for targeted near-infrared photodynamic therapy

Near-infrared (NIR)-to-visible upconversion nanoparticle (UCNP) has shown promising prospects in photodynamic therapy (PDT) as a drug carrier or energy donor. In this work, a photosensitizer pyropheophorbide a (Ppa) and RGD peptide c(RGDyK) comodified chitosan-wrapped NaYF(4):Yb/Er upconversion nanoparticle UCNP-Ppa-RGD was developed for targeted near-infrared photodynamic therapy. The properties of UCNP-Ppa-RGD, such as morphology, stability, optical spectroscopy and singlet oxygen generation efficiency, were investigated. The results show that covalently linked pyropheophorbide a molecule not only is stable but also retains its spectroscopic and functional properties. In vitro studies confirm a stronger targeting specificity of UCNP-Ppa-RGD to integrin α(v)β(3)-positive U87-MG cells compared with that in the corresponding negative group. The photosensitizer-attached nanostructure exhibited low dark toxicity and high phototoxicity against cancer cells upon 980 nm laser irradiation at an appropriate dosage. These results represent the first demonstration of a highly stable and efficient photosensitizer modified upconversion nanostructure for targeted near-infrared photodynamic therapy of cancer cells. The novel UCNP-Ppa-RGD nanoparticle may provide a powerful alternative for near-infrared photodynamic therapy with an improved tumor targeting specificity.     

Ursodeoxycholic acid-conjugated chitosan for photodynamic treatment of HuCC-T1 human cholangiocarcinoma cells

Chitosan was hydrophobically modified with ursodeoxycholic acid (UDCA) to fabricate nano-photosensitizer for photodynamic therapy (PDT) of HuCC-T1 cholangiocarcinoma cells. Synthesis of UDCA-conjugated chitosan (ChitoUDCA) was confirmed using ¹H NMR spectra. Chlorin E6 (Ce6) was used as a photosensitizer and incorporated into ChitoUDCA nanoparticles through formation of ion complexes. Morphology of Ce6-incorporated ChitoUDCA nanoparticles was observed using TEM and their shapes were spherical with sizes around 200–400 nm. The PDT potential of Ce6-incorporated ChitoUDCA nanoparticles were studied with HuCC-T1 human cholangiocarcinoma cells. The results showed that ChitoUDCA nanoparticles enhances of Ce6 uptake into tumor cells, phototoxicity, and ROS generation compared to Ce6 itself. Furthermore, Ce6-incorporated ChitoUDCA nanoparticles showed quenching in aqueous solution and sensing at tumor cells. We suggest that Ce6-incorporated ChitoUDCA nanoparticles are promising candidates for PDT of cholangiocarcinoma cells.     

Gallium phthalocyanine photosensitizers: carboxylation enhances the cellular uptake and improves the photodynamic therapy of cancers

The octacarboxyl gallium (GaPcC) and metal-free (H2PcC) phthalocyanines were prepared using the carboxyl as the peripheral substituent. The carboxylation improves the intracellular delivery of these two PcCs into KB and QGY cancer cells as compared to that of sulfonated aluminum phthalocyanines (AlPcS), a popularly used photosensitizer (PS). Moreover, GaPcC maintains high photoproduction of singlet oxygen. With a short incubation time of 3 hours, GaPcC accumulates sufficiently in both KB and QGY cells and improves photodynamic therapy (PDT) by effectively killing these cancer cells. AlPcS and H2PcC show much lower PDT effects under the same conditions, because AlPcS have a slow cellular uptake rate resulting in a low cellular amount and the ability of H2PcC to produce 1O2 is low. Carboxylation is a promising way to prepare water-soluble metal phthalocyanines (MPcCs) and facilitates the cellular uptake of MPcCs for PDT improvement.     

Cascade two-stage tumor re-oxygenation and immune re-sensitization mediated by self-assembled albumin-sorafenib nanoparticles for enhanced photodynamic immunotherapy

As a promising modality for cancer therapy, photodynamic therapy (PDT) still acquired limited success in clinical nowadays due to the extremely serious hypoxia and immunosuppression tumor microenvironment. To ameliorate such a situation, we rationally designed and prepared cascade two-stage re-oxygenation and immune re-sensitization BSA-MHI148@SRF nanoparticles via hydrophilic and hydrophobic self-assembly strategy by using near-infrared photodynamic dye MHI148 chemically modified bovine serum albumin (BSA-MHI148) and multi-kinase inhibitor Sorafenib (SRF) as a novel tumor oxygen and immune microenvironment regulation drug. Benefiting from the accumulation of SRF in tumors, BSA-MHI148@SRF nanoparticles dramatically enhanced the PDT efficacy by promoting cascade two-stage tumor re-oxygenation mechanisms: (i) SRF decreased tumor oxygen consumption via inhibiting mitochondria respiratory. (ii) SRF increased the oxygen supply via inducing tumor vessel normalization. Meanwhile, the immunosuppression micro-environment was also obviously reversed by two-stage immune re-sensitization as follows: (i) Enhanced immunogenic cell death (ICD) production amplified by BSA-MHI148@SRF induced reactive oxygen species (ROS) generation enhanced T cell infiltration and improve its tumor cell killing ability. (ii) BSA-MHI148@SRF amplified tumor vessel normalization by VEGF inhibition also obviously reversed the tumor immune-suppression microenvironment. Finally, the growth of solid tumors was significantly depressed by such well-designed BSA-MHI148@SRF nanoparticles, which could be potential for clinical cancer therapy.     

Near-infrared imaging of diseases: A nanocarrier approach

Developments in fluorescence imaging, brought popularity to near infrared (NIR) imaging with far-red and NIR fluorophores applied for biosensing and bioimaging in living systems. Noninvasive NIR imaging gained popularity with the use of effective NIR dyes to obtain macroscopic fluorescence images. Several attributes of NIR dyes make them desirable agents, including high specificity, high sensitivity, minimized background interference, and the ability to easily conjugate with drug delivery systems. However, NIR dyes have some drawbacks and limitations, such as low solubility, low stability, and degradation. To overcome these issues, NIR dyes can be encapsulated in appropriate nanocarriers to achieve effective diagnosis, imaging, and therapy monitoring during surgery. Moreover, the vast majority of NIR dyes have photosensitizer features that can effectuate cancer treatment referred to as photodynamic therapy (PDT). In the near future, by combining NIR dyes with appropriate nanocarriers such as liposomes, polymeric micelles, polymeric nanoparticles, dendrimers, quantum dots, carbon nanotubes, or ceramic/silica based nanoparticles, the limitations of NIR dyes can be minimized or even effectively eliminated to form potential effective agents for imaging, therapy, and therapy monitoring of several diseases, particularly cancer.     

Co-delivery of photosensitizer and diclofenac through sequentially responsive bilirubin nanocarriers for combating hypoxic tumors

Considering that photodynamic therapy (PDT)-induced oxygen consumption and microvascular damage could exacerbate hypoxia to drive more glycolysis and angiogenesis, a novel approach to potentiate PDT and overcome the resistances of hypoxia is avidly needed. Herein, morpholine-modified PEGylated bilirubin was proposed to co-deliver chlorin e6, a photosensitizer, and diclofenac (Dc). In acidic milieu, the presence of morpholine could enable the nanocarriers to selectively accumulate in tumor cells, while PDT-generated reactive oxidative species (ROS) resulted in the collapse of bilirubin nanoparticles and rapid release of Dc. Combining with Dc showed a higher rate of apoptosis over PDT alone and simultaneously triggered a domino effect, including blocking the activity and expression of lactate dehydrogenase A (LDHA), interfering with lactate secretion, suppressing the activation of various angiogenic factors and thus obviating hypoxia-induced resistance-glycolysis and angiogenesis. In addition, inhibition of hypoxia-inducible factor-1α (HIF-1α) by Dc alleviated hypoxia-induced resistance. This study offered a sequentially responsive platform to achieve sufficient tumor enrichment, on-demand drug release and superior anti-tumor outcomes in vitro and in vivo.     

Iodinated cyanine dye-based nanosystem for synergistic phototherapy and hypoxia-activated bioreductive therapy

Photodynamic therapy (PDT) has been applied in cancer treatment by utilizing reactive oxygen species (ROS) to kill cancer cells. However, the effectiveness of PDT is greatly reduced due to local hypoxia. Hypoxic activated chemotherapy combined with PDT is expected to be a novel strategy to enhance anti-cancer therapy. Herein, a novel liposome (LCT) incorporated with photosensitizer (PS) and bioreductive prodrugs was developed for PDT-activated chemotherapy. In the design, CyI, an iodinated cyanine dye, which could simultaneously generate enhanced ROS and heat than other commonly used cyanine dyes, was loaded into the lipid bilayer; while tirapazamine (TPZ), a hypoxia-activated prodrug was encapsulated in the hydrophilic nucleus. Upon appropriate near-infrared (NIR) irradiation, CyI could simultaneously produce ROS and heat for synergistic PDT and photothermal therapy (PTT), as well as provide fluorescence signals for precise real-time imaging. Meanwhile, the continuous consumption of oxygen would result in a hypoxia microenvironment, further activating TPZ free radicals for chemotherapy, which could induce DNA double-strand breakage and chromosome aberration. Moreover, the prepared LCT could stimulate acute immune response through PDT activation, leading to synergistic PDT/PTT/chemo/immunotherapy to kill cancer cells and reduce tumor metastasis. Both in vitro and in vivo results demonstrated improved anticancer efficacy of LCT compared with traditional PDT or chemotherapy. It is expected that these iodinated cyanine dyes-based liposomes will provide a powerful and versatile theranostic strategy for tumor target phototherapy and PDT-induced chemotherapy.     

Multi-responsive nanotheranostics with enhanced tumor penetration and oxygen self-producing capacities for multimodal synergistic cancer therapy

Incorporation of multiple functions into one nanoplatform can improve cancer diagnostic efficacy and enhance anti-cancer outcomes. Here, we constructed doxorubicin (DOX)-loaded silk fibroin-based nanoparticles (NPs) with surface functionalization by photosensitizer (N770). The obtained nanotheranostics (N770-DOX@NPs) had desirable particle size (157 nm) and negative surface charge (?25 mV). These NPs presented excellent oxygen-generating capacity and responded to a quadruple of stimuli (acidic solution, reactive oxygen species, glutathione, and hyperthermia). Surface functionalization of DOX@NPs with N770 could endow them with active internalization by cancerous cell lines, but not by normal cells. Furthermore, the intracellular NPs were found to be preferentially retained in mitochondria, which were also efficient for near-infrared (NIR) fluorescence imaging, photothermal imaging, and photoacoustic imaging. Meanwhile, DOX could spontaneously accumulate in the nucleus. Importantly, a mouse test group treated with N770-DOX@NPs plus NIR irradiation achieved the best tumor retardation effect among all treatment groups based on tumor-bearing mouse models and a patient-derived xenograft model, demonstrating the unprecedented therapeutic effects of trimodal imaging-guided mitochondrial phototherapy (photothermal therapy and photodynamic therapy) and chemotherapy. Therefore, the present study brings new insight into the exploitation of an easy-to-use, versatile, and robust nanoplatform for programmable targeting, imaging, and applying synergistic therapy to tumors.     

Trimodal synergistic antitumor drug delivery system based on graphene oxide

A multifunctional antitumor drug delivery system was synthesized based on graphene oxide (GO) for near-infrared (NIR) light controlling chemotherapeutic/photothermal (PTT) /photodynamic (PDT) trimodal synergistic therapy. The system named ICG-Wed-GO was formed by co-loading wedelolactone (Wed) and indocyanine green (ICG) on the surface of GO through π–π stacking interaction. Under NIR laser irradiation, ICG-Wed-GO could effectively absorb and transform optical energy to heat, generate reactive oxygen species (ROS) to ablating and damage tumor cells. The temperature of ICG-Wed-GO solution reached up to 79.4?°C in 10?min with NIR irradiation. In in vitro and in vivo study, ICG-Wed-GO showed excellent antitumor effect. After 14-day treatment of ICG-Wed-GO with NIR laser irradiation, the tumor disappeared completely on tumor-bearing mice. The low biotoxicity of ICG-Wed-GO was also proved. The system achieved the synergistic trimodal chemotherapeutic/photothermal/photodynamic treatment and demonstrated excellent antitumor effect, which is expected to have a greater potential for cancer therapy.     

Enhanced photodynamic efficacy towards melanoma cells by encapsulation of Pc4 in silica nanoparticles

Nanoparticles have been explored recently as an efficient means of delivering photosensitizers for cancer diagnosis and photodynamic therapy (PDT). Silicon phthalocyanine 4 (Pc4) is currently being clinically tested as a photosensitizer for PDT. Unfortunately, Pc4 aggregates in aqueous solutions, which dramatically reduces its PDT efficacy and therefore limits its clinical application. We have encapsulated Pc4 using silica nanoparticles (Pc4SNP), which not only improved the aqueous solubility, stability, and delivery of the photodynamic drug but also increased its photodynamic efficacy compared to free Pc4 molecules. Pc4SNP generated photo-induced singlet oxygen more efficiently than free Pc4 as measured by chemical probe and EPR trapping techniques. Transmission electron microscopy and dynamic light scattering measurements showed that the size of the particles is in the range of 25–30 nm. Cell viability measurements demonstrated that Pc4SNP was more phototoxic to A375 or B16-F10 melanoma cells than free Pc4. Pc4SNP photodamaged melanoma cells primarily through apoptosis. Irradiation of A375 cells in the presence of Pc4SNP resulted in a significant increase in intracellular protein-derived peroxides, suggesting a Type II (singlet oxygen) mechanism for phototoxicity. More Pc4SNP than free Pc4 was localized in the mitochondria and lysosomes. Our results show that these stable, monodispersed silica nanoparticles may be an effective new formulation for Pc4 in its preclinical and clinical studies. We expect that modifying the surface of silicon nanoparticles encapsulating the photosensitizers with antibodies specific to melanoma cells will lead to even better early diagnosis and targeted treatment of melanoma in the future.     

Multifunctional nanoplatforms for fluorescence imaging and photodynamic therapy developed by post-loading photosensitizer and fluorophore to polyacrylamide nanoparticles

We report a novel post-loading approach for constructing a multifunctional biodegradable polyacrylamide (PAA) nanoplatform for tumor-imaging (fluorescence) and photodynamic therapy (PDT). This approach provides an opportunity to post-load the imaging and therapeutic agents at desired concentrations. Among the PAA nanoparticles, a formulation containing the photosensitizer, HPPH [3-(1′-hexyloxyethyl)pyropheophorbide-a], and the cyanine dye in a ratio of 2:1 minimized the undesirable quenching of the HPPH electronic excitation energy because of energy migration within the nanoparticles and/or Förster (fluorescence) resonance energy transfer (FRET) between HPPH and cyanine dye. An excellent tumor-imaging (NIR fluorescence) and phototherapeutic efficacy of the nanoconstruct formulation is demonstrated. Under similar treatment parameters the HPPH in 1% Tween 80/5% aqueous dextrose formulation was less effective than the nanoconstruct containing HPPH and cyanine dye in a ratio of 2 to 1. This is the first example showing the use of the post-loading approach in developing a nanoconstructs for tumor-imaging and therapy.From the Clinical EditorFluorescence imaging is a rapidly evolving and relatively high-throughput tool currently only utilized in preclinical imaging. The authors of this work demonstrate a tumor-specific florescence imaging nanoplatform that enables not only imaging, but photodynamic therapy as well.     

Hypericin lights up the way for the potential treatment of nasopharyngeal cancer by photodynamic therapy

Photodynamic therapy (PDT) involves the administration of a photosensitizer followed by light irradiation with a specific wavelength, giving rise to irreversible tissue destruction. Hypericin, a herbal extract derived from Hypericum perforatum or St. John's Wort, has minimal toxicity but exhibits potent photo-damaging effects in the presence of light. Hypericin is known to generate a high yield of singlet oxygen and other reactive oxygen species that are associated with photo-oxidative cellular damage. The application of PDT with hypericin for the treatment of cancers such as recurrent mesothelioma and skin cancer has been validated in clinical trials. This mini-review focuses on the investigative studies of hypericin as a potential photodynamic agent in the treatment of nasopharyngeal cancer (NPC) in in vitro and in vivo models. NPC is an enigmatic tumor with a multifactorial etiology and a high incidence in the populations of Southern China.