Photosynthetic Microorganisms-Based Biophotothermal Therapy with Enhanced Immune Response.

The production of oxygen by photosynthetic microorganisms (PSMs) has recently attracted interest concerning the in vivo treatment of multiple diseases for their photosynthetic oxygen production in vivo, since PSMs have good biological safety. Here, the first evidence that PSMs can be used as a photothermal source to perform biophotothermal therapy (bio-PTT) is provided. In vitro and in vivo experiments proved that PSMs can generate heat for the direct elimination of tumors and release a series of pathogen-associated molecular patterns and adjuvants for immune stimulation under light irradiation. Bio-PTT enabled a local tumor inhibition rate exceeding 90% and an abscopal tumor inhibition rate exceeding 75%. This strategy also produced a stronger antitumor immune memory effect to prevent tumor recurrence. The bio-PTT strategy provides a novel direction for photothermal therapy as it simultaneously produces local and abscopal antitumor effects.

Sodium tanshinone IIA sulfonate attenuates cardiac dysfunction and improves survival of rats with cecal ligation and puncture-induced sepsis.

Cardiac dysfunction, a common consequence of sepsis, is the major contribution to morbidity and mortality in patients. Sodium tanshinone IIA sulfonate (STS) is a water-soluble derivative of Tanshinone IIA (TA), a main active component of Salvia miltiorrhiza Bunge, which has been widely used in China for the treatment of cardiovascular and cerebral system diseases. In the present study, the effect of STS on sepsis-induced cardiac dysfunction was investigated and its effect on survival rate of rats with sepsis was also evaluated. STS treatment could significantly decrease the serum levels of C-reactive protein (CRP), procalcitonin (PCT), cardiac troponin I (cTn-I), cardiac troponin T (cTn-T), and brain natriuretic peptide (BNP) in cecal ligation and puncture (CLP)-induced) septic rats and improve left ventricular function, particularly at 48 and 72 h after CLP. As the pathogenesis of septic myocardial dysfunction is attributable to dysregulated systemic inflammatory responses, several key cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), interleukin-10 (IL-10) and high mobility group protein B1 (HMGB1), were detected to reveal the possible mechanism of attenuation of septic myocardial dysfunction after being treated by STS. Our study showed that STS, especially at a high dose (15 mg·kg-1), could efficiently suppress inflammatory responses in myocardium and reduce myocardial necrosis through markedly reducing production of myocardial TNF-α, IL-6 and HMGB1. STS significantly improved the 18-day survival rate of rats with sepsis from 0% to 30% (P < 0.05). Therefore, STS could suppress inflammatory responses and improve left ventricular function in rats with sepsis, suggesting that it may be developed for the treatment of sepsis.

Enhanced photodynamic therapy by encapsulation of perfluorocarbon into PEGylated near-infared dyes.

Near-Infrared (NIR) dyes, with improved tissue penetration, minimal invasiveness and high specificity, have gained great interests in diagnosing and treating tumors. However, the poor solubility in aqueous medium and low 1O2 quantum yields of NIR dyes restrict their application in PDT (photodynamic therapy) research. Herein, a novel nanosystem with modifying the NIR dyes and encapsulating perfluorocarbon is reported for improving the PDT effectiveness of NIR dyes. By adding the PEG2000-SH and the C13 carbon chain to a NIR representative dye IR780, the new formed material PEG-IR780-C13 shows good solubility in water. Then PFTBA was encapsulated into PEG-IR780-C13 to form a nanosystem (PFTBA@PEG-IR780-C13). When exposed to laser irradiation, the nanosystem showed enhanced production of 1O2 and significantly increased PDT both in vivo and in vitro. Therefore, this work provides an approach for design and application of NIR dyes.

Self-assembled albumin nanoparticles for combination therapy in prostate cancer.

Resistance to regular treatment strategies is a big challenge in the treatment of castration-resistant prostate cancer. Combination of photothermal and photodynamic therapy (PTT/PDT) with chemotherapy offers unique advantages over monotherapy alone. However, free drugs, such as photosensitizers and chemotherapeutic agents, lack tumor-targeted accumulation and can be easily eliminated from the body. Moreover, most of the PTT drugs are hydrophobic and their organic solvents have in vivo toxicity, thereby limiting their potential in clinical translation. Herein, simple multifunctional nanoparticles (NPs) using IR780 (a near-infrared dye) and docetaxel (DTX)-loaded nanoplatform based on human serum albumin (HSA) (HSA@IR780@DTX) was developed for targeted imaging and for PTT/PDT with chemotherapy for the treatment of castration-resistant prostate cancer treatment. In this platform, HSA is a biocompatible nanocarrier that binds to both DTX and IR780. DTX and IR780, as hydrophobic drug, can induce the self-assembly of HSA proteins. Transmission electron microscopic imaging showed that NPs formed by self-assembly are spherical with a smooth surface with a hydrodynamic diameter of 146.5±10.8 nm. The cytotoxicity of HSA@IR780@DTX NPs with or without laser irradiation in prostate cancer cells (22RV1) was determined via CCK-8 assay. The antitumor effect of HSA@IR780@DTX plus laser irradiation was better than either HSA@IR780@DTX without laser exposure or single PTT heating induced by HSA@IR780 NPs under near-infrared laser, suggesting a significant combined effect in comparison to monotherapy. Near-infrared fluorescence imaging showed that HSA@IR780@DTX NPs could preferentially accumulate in tumors. In vivo therapeutic efficacy experiment showed that xenografted prostate tumors on mice treated with HSA@IR780@DTX plus near-infrared laser irradiation were completely inhibited, whereas tumors on mice treated with chemotherapy alone (HSA@DTX and HSA@IR780@DTX without laser) or PTT/PDT alone (HSA@IR780 with laser) showed moderate growth inhibition. Overall, HSA@IR780@DTX NPs showed notable targeting and theranostic potential for the treatment of castration-resistant prostate cancer.

Oxygen self-enriched nanoparticles functionalized with erythrocyte membranes for long circulation and enhanced phototherapy.

In recent years, indocyanine green (ICG) encapsulated in different kinds of nano-carriers have been developed to overcome its short lifetime in vivo and non-selectivity in cancer cells. However, these nanoparticles are still easily recognized and captured by the reticuloendothelial system (RES) and the low singlet oxygen quantum (0.08) of ICG inevitably leads to a limited efficacy of phototherapy. To overcome these limitations, a novel oxygen self-enriched biomimetic red blood cell (RBC) was developed by cloaking albumin nanoparticles which contained ICG and perfluorocarbon (PFC) with RBC membranes. Due to the high oxygen capacity of PFC, the oxygen self-enriched nanoparticles can enhance photodynamic therapy (PDT) by generating more singlet oxygen (1O2). After successfully coated RBC membranes onto nanoparticles, the novel oxygen self-enriched biomimetic RBCs remained the characteristics of photothermal therapy (PTT) and enhanced PDT in vitro. Importantly, it can effectively reduce immune clearance in macrophage cells (RAW264.7) and significantly prolong blood circulation time, achieving high accumulation in tumor. In addition, the tumor growth was effectively inhibited after intravenous injection to tumor-bearing mice. Altogether, this oxygen self-enriched RBCs with long circulation time and high oxygen capacity as natural RBCs provide a new strategy to design biomimetic nano-system for clinical cancer phototherapy treatment. STATEMENT OF SIGNIFICANCE: Near-infrared (NIR) dyes encapsulated in nanocarriers have been achieved great interest in cancer phototherapy treatment. However, the low singlet oxygen (1O2) quantum of NIR dyes and short circulation time of nanoparticles lead to unsatisfactory efficacy, limiting their applications. In this study, a novel oxygen self-enriched biomimetic red blood cell (bio-RBC) was developed to produce fluorescence, imaging-guided for photothermal therapy (PTT) and enhanced photodynamic therapy (PDT). It was composed of RBC membranes and albumin nanoparticles (IPH) which contained indocyanine green (ICG) and perfluorocarbon (PFC). After RBC membranes successfully being coated on nanoparticles, bio-RBC can effectively reduce immune clearance in macrophage cells and achieve longer circulation time in vivo, due to the protein retention in RBC membranes. In addition, PFC with high oxygen capacity can provide more oxygen to generate more 1O2 and dissolve 1O2 to enhance its life-time, enhancing PDT cancer treatment. In summary, the novel bio-RBC with longer lifetime and higher oxygen capacity as natural RBCs can significantly accumulate on tumor and effectively enhance phototherapy. It could serve as a novel strategy to overcome the problems of NIR dyes encapsulated nanoparticles, promising for future clinical application.

Self-assembled hemoglobin nanoparticles for improved oral photosensitizer delivery and oral photothermal therapy in vivo.

AIM: The aim of the present study was to use hemoglobin (Hb) nanoparticles (NPs) to improve oral bioavailability of a near-infrared dye IR780 for in vivo antitumor application in photothermal therapy. METHODS: One-step acid-denaturing method was used to encapsulate IR780 into self-assembled Hb NPs (IR780@Hb NPs). Pharmacokinetics, biodistribution and antitumor effect were studied in vivo. RESULTS: The Hb NPs showed high stability in enzymatic and acidic conditions similar to the gastric environment, and enhanced absorption of IR780 into the blood. In vivo imaging revealed that IR780 could accumulate at the tumor sites and effectively caused photothermal effect, which resulted in tumor ablation after oral administration in tumor-bearing mice. CONCLUSION: Hb NPs represent a promising delivery system for improving oral absorption of photosensitizer dyes, which could open new treatment modalities in cancer.

NIR Light-Activated Drug Release for Synergetic Chemo-Photothermal Therapy.

Nanocarriers like PEGylated liposomes have achieved enhanced drug accumulation in tumors and reduced systemic side effects, but failed to actively release the carried drug into cancer cells. To obtain improved therapeutic efficacy, we designed a novel liposome that was inserted by the amphiphilic agent PEG-IR780-C13 (PIC-Lipo) and encapsulated therapeutic agent doxorubicin (DOX), termed as DOX@PIC-Lipo. Upon NIR laser irradiation, the novel liposomes could generate hyperthermia and facilitate the release of encapsulated DOX from PIC-Lipo, which were confirmed by photothermal curves and the DOX release assay in vitro, respectively. In addition, the enhanced DOX release and sufficient hyperthermia have performed synergetic therapeutic efficacy both in vitro and in vivo. Therefore, DOX@PIC-Lipo might provide an active strategy to release the loaded drug for synergetic chemo-photothermal combined therapy.

Self-assembled IR780-loaded transferrin nanoparticles as an imaging, targeting and PDT/PTT agent for cancer therapy.

Combination of photothermal and photodynamic therapy (PTT/PDT) offer unique advantages over PDT alone. However, to achieve synergetic PDT/PTT effect, one generally needs two lasers with different wavelengths. Near-infrared dye IR-780 could be used as photosensitizer both for PTT and PDT, but its lipophilicity limits its practical use and in vivo efficiency. Herein, a simple multifunctional IR780-loaded nanoplatform based on transferrin was developed for targeted imaging and phototherapy of cancer compatible with a single-NIR-laser irradiation. The self-assembled transferrin-IR780 nanoparticles (Tf-IR780 NPs) exhibited narrow size distribution, good photo-stability, and encouraging photothermal performance with enhanced generation of ROS under laser irradiation. Following intravenous injection, Tf-IR780 NPs had a high tumor-to-background ratio in CT26 tumor-bearing mice. Treatment with Tf-IR780 NPs resulted in significant tumor suppression. Overall, the Tf-IR780 NPs show notable targeting and theranostic potential in cancer therapy.

Photothermal Ablation of in Situ Renal Tumor by PEG-IR780-C13 Micelles and Near-Infrared Irradiation.

PEG-IR780-C13 micelles have been demonstrated to be a novel photothermal agent with tumor-targeting property. This study was designed to explore the feasibility of applying PEG-IR780-C13 micelles and near-infrared (NIR) irradiation for thermal ablation of renal tumor by using an in situ tumor model. In addition, the potential thermal injury to normal renal tissue was evaluated. PEG-IR780-C13 micelles were intended to accumulate in renal tumor after systemic delivery. In vitro results revealed that PEG-IR780-C13 micelles were uptaken by RENCA cells mainly through caveola-mediated endocytosis and mainly distributed in late endosomes and lysosomes. Upon NIR irradiation, PEG-IR780-C13 micelles generated heat effectively both in vitro and in vivo, exhibiting a promising photothermal therapeutic property. The photothermal effect of PEG-IR780-C13 micelles could effectively destroy RENCA cells in vitro and adequately inhibit growth of in situ renal tumor in vivo. Meanwhile, PEG-IR780-C13 micelles mediated photothermal therapy (PTT) resulting in only limited injury to normal renal tissue surrounding tumor sites. Our data indicated that PEG-IR780-C13 micelles mediating PTT could generate tumor-specific heat for destruction of renal tumor in a minimally invasive way, providing a novel strategy for thermal ablation of renal tumor.

Self-assembled PEG-IR-780-C13 micelle as a targeting, safe and highly-effective photothermal agent for in vivo imaging and cancer therapy.

IR-780, a representative hydrophobic near-infrared (NIR) fluorescence dye, is capable of fluorescently imaging and photothermal therapy in vitro and in vivo. However, insolubility in all pharmaceutically acceptable solvents limits its further biological applications. To increase solubility, we developed a novel self-assembled IR-780 containing micelle (PEG-IR-780-C13) based on the structural modification of IR-780. Briefly, a hydrophilic PEG2000 was modified on the one side of IR-780, and the hydrophobic carbon chain on the other side was extended from C3 to C16 (additional C13 carbon chain). The modification provides a better self-assemble capability, improved water solubility and higher stability. In addition, PEG-IR-780-C13 micelles are specifically targeted to the tumor after intravenous injection and can be used for tumor imaging. The in vitro cell viability assays and in vivo photothermal therapy experiments indicated that CT-26 cells or CT-26 xenograft tumors can be effectively ablated by combining PEG-IR-780-C13 micelles with 808 nm laser irradiation. More importantly, no significant toxicity can be observed after intravenous administration of the therapeutic dose of generated micelles. Overall, our micelles may have the least safety concern while showing excellent treatment efficacy, and thus may be a new photothermal agent potentially useful in clinical applications.

Hydrophobic IR780 encapsulated in biodegradable human serum albumin nanoparticles for photothermal and photodynamic therapy.

It has been reported that IR780 iodide, a near-infrared dye, can be applied for cancer imaging, photodynamic therapy (PDT) and photothermal therapy (PTT). However, the hydrophobicity and toxicity of IR780 severely limit its further clinical applications. In this study, human serum albumin was used to load IR780 to form nanoparticles (HSA-IR780 NPs) by protein self-assembly. Compared to free IR-780, the solubility of HSA-IR780 NPs was greatly increased (1000-fold) while the toxicity was decreased (from 2.5 mg kg(-1) to 25 mg kg(-1)). Moreover, both PTT and PDT could be observed in HSA-IR780 NPs, as determined by increased temperature and enhanced generation of singlet oxygen after laser irradiation at a wavelength of 808 nm. In vivo studies also showed a great tumor inhibition by the injection of HSA-IR780 NPs into tumor-bearing mice. Therefore, HSA-IR780 NPs may serve as a promising substitute for IR780 in further clinical PDT and PTT.

A sandwiched microarray platform for benchtop cell-based high throughput screening.

The emergence of combinatorial chemistries and the increased discovery of natural compounds have led to the production of expansive libraries of drug candidates and vast numbers of compounds with potentially interesting biological activities. Despite broad interest in high throughput screening (HTS) across varied fields of biological research, there has not been an increase in accessible HTS technologies. Here, we present a simple microarray sandwich system suitable for screening chemical libraries in cell-based assays at the benchtop. The microarray platform delivers chemical compounds to isolated cell cultures by 'sandwiching' chemical-laden arrayed posts with cell-seeded microwells. In this way, an array of sealed cell-based assays was generated without cross-contamination between neighbouring assays. After chemical exposure, cell viability was analyzed by fluorescence detection of cell viability assays on a per microwell basis using a standard microarray scanner. We demonstrate the efficacy of the system by generating four hits from toxicology screens towards MCF-7 human breast cancer cells. Three of the hits were identified in a combinatorial screen of a library of natural compounds in combination with verapamil, a P-glycoprotein inhibitor. A fourth hit, 9-methoxy-camptothecin, was identified by screening the natural compound library in the absence of verapamil. The method developed here miniaturizes existing HTS systems and enables the screening of a wide array of individual or combinatorial libraries in a reproducible and scalable manner. We anticipate broad application of such a system as it is amenable to combinatorial drug screening in a simple, robust and portable platform.