Tumor-Targeted cRGD-Coated Liposomes Encapsulating Optimized Synergistic Cepharanthine and IR783 for Chemotherapy and Photothermal Therapy.

Background: Combination therapy offers superior therapeutic results compared to monotherapy. However, the outcomes of combination therapy often fall short of expectations, mainly because of increased toxicity from drug interactions and challenges in achieving the desired spatial and temporal distribution of drug delivery. Optimizing synergistic drug combination ratios to ensure uniform targeting and distribution across space and time, particularly in vivo, is a significant challenge. In this study, cRGD-coated liposomes encapsulating optimized synergistic cepharanthine (CEP; a chemotherapy drug) and IR783 (a phototherapy agent) were developed for combined chemotherapy and photothermal therapy in vitro and in vivo. Methods: An MTT assay was used to evaluate the combination index of CEP and IR783 in five cell lines. The cRGD-encapsulated liposomes were prepared via thin-film hydration, and unencapsulated liposomes served as controls for the loading of CEP and IR783. Fluorescence and photothermal imaging were used to assess the efficacy of CEP and IR783 encapsulated in liposomes at an optimal synergistic ratio, both in vitro and in vivo. Results: The combination indices of CEP and IR783 were determined in five cell lines. As a proof-of-concept, the optimal synergistic ratio (1:2) of CEP to IR783 in 4T1 cells was evaluated in vitro and in vivo. The average diameter of the liposomes was approximately 100 nm. The liposomes effectively retained the encapsulated CEP and IR783 in vitro at the optimal synergistic molar ratio for over 7 d. In vivo fluorescence imaging revealed that the fluorescence signal from cRGD-CEP-IR783-Lip was detectable at the tumor site at 4 h post-injection and peaked at 8 h. In vivo photothermal imaging of tumor-bearing mice indicated an increase in tumor temperature by 32°C within 200 s. Concurrently, cRGD-CEP-IR783-Lip demonstrated a significant therapeutic effect and robust biosafety in the in vivo antitumor experiments. Conclusion: The combination indices of CEP and IR783 were successfully determined in vitro in five cell lines. The cRGD-coated liposomes encapsulated CEP and IR783 at an optimal synergistic ratio, exhibiting enhanced antitumor effects and targeting upon application in vitro and in vivo. This study presents a novel concept and establishes a research framework for synergistic chemotherapy and phototherapy treatment.

A near-infrared and lysosome-targeted BODIPY photosensitizer for photodynamic and photothermal synergistic therapy.

Phototherapy is a promising approach for the treatment of cancers and other diseases. So far, many photosensitizers have been developed for photodynamic therapy (PDT) or photothermal therapy (PTT). However, it remains a challenge to develop a system for synergistic PDT and PTT with specific targeting and real-time fluorescence tracking. Herein, we designed a multifunctional BODIPY derivative, Lyso-BDP, for synergistic PDT and PTT against tumors. Lyso-BDP was composed of three parts: (1) the BODIPY fluorophore was selected as a theranostic core, (2) a morpholine group modified on meso-BODIPY served as a lysosome-targeting unit for enhancing the antitumor effect, and (3) N,N-diethyl-4-vinylaniline was attached to the BODIPY core to extend its wavelength to the near-infrared region. Finally, Lyso-BDP shows near-infrared absorption and emission, photosensitizing activity, lysosomal targeting, and synergistic PDT and PTT effects, and effectively kills cancer cells both in vitro and in vivo. Therefore, our study demonstrates that Lyso-BDP can serve as a promising photosensitizer in the therapy of cancer with potential clinical application prospects.

A Lysosome-Targeted Near-Infrared Fluorescent Probe with Excellent Water Solubility for Surgery Navigation in Breast Cancer.

To get a tumor-targeted contrast agent for imaging guide resection of tumors, we designed a novel fluorescent probe based on the heptamethine cyanine core, Cy7-MO, which has excellent water solubility and near-infrared photophysical and lysosomal targeting properties. The chemical structure of Cy7-MO was characterized by nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. The toxicity of Cy7-MO was evaluated by cell counting kit-8. Then, a cellular-level study was conducted to evaluate the suborganelle localization in 4T1-Luc1 cells, and it was also used for surgical navigation in orthotopic breast tumor resection in vivo. The results showed that Cy7-MO was well targeted to lysosomes. Importantly, the Cy7-MO probe was found to be well tolerable and exhibited excellent biocompatibility. Moreover, the orthotopic breast tumor margin was clearly visualized through fluorescence guiding of Cy7-MO. Finally, the correct tumor tissues were completely removed, and a negative margin was obtained successfully, which demonstrated an enhanced precision of surgery.

A simple and sensitive electrochemical sensor for the detection of peptidase activity.

In this work, a simple and sensitive electrochemical sensor was proposed for the detection of ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) activity. Firstly, the BACE1 specific peptide was modified onto the Au electrode to graft a single-strand DNA with polycytosine DNA sequence (dC12) via amide bonding between peptide and dC12. Because the dC12 is abundant in phosphate groups, thus it can react with molybdate to form redox molybdophosphate, which can generate electrochemical current. Using BACE1 as a model peptidase, the proposed sensor shows a linear response range from 1 to 15 U/mL and limit of detection down to 0.05 U/mL. The sensor displays good performance for the BACE1 activity detection in human serum samples, which may have potential applications in the clinical diagnostics of Alzheimer's disease.

An oxygen-carrying and lysosome-targeting BODIPY derivative for NIR bioimaging and enhanced multimodal therapy against hypoxic tumors.

Cancer treatment modalities have gradually shifted from monotherapies to multimodal therapies. It is still a challenge to develop a synergistic chemo-phototherapy system with relieving tumor hypoxia, specific targeting, and real-time fluorescence tracking. In this study, we designed a multifunctional BODIPY derivative, FBD-M, for synergistic chemo-phototherapy against hypoxic tumors. FBD-M was composed of four parts: 1) The BODIPY fluorophore selected as a theranostic core, 2) A pentafluorobenzene group modified on meso-BODIPY to carry oxygen, 3) A morpholine group hooked to one side of BODIPY served as a lysosome-targeting unit for enhancing antitumor effect, and 4) An aromatic nitrogen mustard group introduced on other side of BODIPY to achieve chemotherapy. After introducing the morpholine and aromatic nitrogen mustard in BODIPY, the conjugate system of BODIPY was also expanded to realize near-infrared (NIR) phototherapy. Finally, FBD-M was obtained by a rational design, which possessed with NIR absorbance and emission, photosensitive activity, oxygen-carrying capability for relieving tumor hypoxia, high photothermal conversion efficiency, good photostability, lysosome targeting, low toxicity, and synergistic chemo-phototherapy against hypoxic tumors. FBD-M had been successfully applied for anticancer in vitro and in vivo. Our study demonstrates that FBD-M can serve as an ideal multifunctional theranostic agents.

Monitoring Cell Plasma Membrane Polarity by a NIR Fluorescence Probe with Unexpected Cell Plasma Membrane-Targeting Ability.

The cell plasma membrane, the natural barrier of a cell, plays critical roles in a mass of cell physiological and pathological processes. Therefore, revealing and monitoring the local status of the cell plasma membrane are of great significance. Herein, using a near-infrared (NIR) fluorescence probe BTCy, microenvironmental polarity in the cell plasma membrane was in situ monitored. BTCy showed sensitive and selective fluorescence decrease response at 706 nm with the increase of polarity as its polarity-responsive D-π-A structure. Most importantly, BTCy showed unexpected cell plasma membrane-targeting ability, probably due to its amphiphilic structure. With BTCy, the distinguishing imaging of cancer and normal cells was done, in which cancer cells exhibited significantly stronger signals due to their lower cell plasma membrane polarity. In addition, with the imaging of BTCy, the ferroptosis process was revealed with no significant cell plasma membrane polarity variation for the first time. Furthermore, BTCy was employed for in vivo imaging of tumor tissue in the 4T1-tumor-bearing mice. The polarity-responsive and cell plasma membrane-targeting properties of BTCy make it a useful tool for monitoring cell plasma membrane polarity variation, providing an efficient and simple method for tumor diagnosis.

Near-Infrared Turn-On Fluorescent Probe for Aqueous Fluoride Ion Detection and Cell Imaging.

Fluoride ions are one of the most essential anions in the human body and have been implicated in various pathological and physiological processes. The detection of fluoride ions in aqueous solution, as well as the imaging of fluoride ions in living cells, remains a challenge. We herein report a BODIPY-based fluorescent probe employing a pinacol borate group as the recognition moiety for the detection of fluoride ions in aqueous solutions. This probe shows high selectivity and sensitivity to fluoride ions with a significant near-infrared fluorescence turn-on response. In addition, this probe was successfully employed in fluorescence bioimaging of fluoride ions in the human cervical cancer cell and mouse mammary cancer cell, demonstrating its good cell permeability and stability under physiological conditions.

Chemiluminescence in Combination with Organic Photosensitizers: Beyond the Light Penetration Depth Limit of Photodynamic Therapy.

Photodynamic therapy (PDT) is a promising noninvasive medical technology that has been approved for the treatment of a variety of diseases, including bacterial and fungal infections, skin diseases, and several types of cancer. In recent decades, many photosensitizers have been developed and applied in PDT. However, PDT is still limited by light penetration depth, although many near-infrared photosensitizers have emerged. The chemiluminescence-mediated PDT (CL-PDT) system has recently received attention because it does not require an external light source to achieve targeted PDT. This review focuses on the rational design of organic CL-PDT systems. Specifically, PDT types, light wavelength, the chemiluminescence concept and principle, and the design of CL-PDT systems are introduced. Furthermore, chemiluminescent fraction examples, strategies for combining chemiluminescence with PDT, and current cellular and animal applications are highlighted. Finally, the current challenges and possible solutions to CL-PDT systems are discussed.

Novel Lysosome-Targeting Fluorescence Off-On Photosensitizer for Near-Infrared Hypoxia Imaging and Photodynamic Therapy In Vitro and In Vivo.

Photodynamic therapy (PDT) has emerged as a new antitumor modality. Hypoxia, a vital characteristic of solid tumors, can be explored to stimulate the fluorescence response of photosensitizers (PSs). Considering the characteristics of PDT, the targeting of organelles employing PS would enhance antitumor effects. A new multifunctional cyanine-based PS (CLN) comprising morpholine and nitrobenzene groups was prepared and characterized. It generated fluorescence in the near-infrared (NIR) region in the presence of sodium dithionite (Na2S2O4) and nitroreductase (NTR). The response mechanism of CLN was well investigated, thus revealing that its obtained reduction product was CLNH. The obtained fluorescence and singlet oxygen quantum yield of CLNH were 8.65% and 1.60%, respectively. Additionally, the selective experiment for substrates indicated that CLN exhibited a selective response to NTR. Thus, CLN fluorescence could be selectively switched on and its fluorescence intensity increased, following a prolonged stay in hypoxic cells. Furthermore, fluorescence colocalization demonstrated that CLN could effectively target lysosomes. CLN could generate reactive oxygen species and kill tumor cells (IC50 for 4T1 cells was 7.4 µM under a hypoxic condition), following its response to NTR. NIR imaging and targeted PDT were finally applied in vivo.

A 1,2-Dioxetane-Based Chemiluminescent Probe for Highly Selective and Sensitive Detection of Superoxide Anions in†Vitro and in†Vivo.

Superoxide anion (O2.- ), a short-lived, highly active reactive oxygen species, participates in many physiological processes. This work reports the design of a chemiluminescent probe (CLO) based on 1,2-dioxetane-phenol with a selective and sensitive response to O2.- . The CLO consisted of a 1,2-dioxetane-phenol as a chemiluminophore core bearing a trifluoromethanesulfonate (Tf) moiety and methyl acrylate group. Upon reacting with O2.- , the Tf was specifically cleaved from the CLO, resulting in chemiluminescence generation. The CLO emits chemiluminescence at 450-650 nm (λmax =540 nm), representing visible and red chemiluminescent molecules, responsive to O2.- . The CLO processes high sensitivity (Limit of detection=66 nM) and selectivity for O2.- with and has been applied to track O2.- fluctuations in living cells and animals. In addition, CLO successfully detected and visualized O2.- -related biochemical processes, making it promising as an important imaging tool for studying redox in biology and medicine.

a Versatile Schiff Base Chemosensor for the Determination of Trace Co2+, Ni2+, Cu2+, and Zn2+ in the Water and Its Bioimaging Applications.

In this work, a simple and versatile Schiff base chemosensor (L) was developed for the detection of four adjacent row 4 metal ions (Co2+, Ni2+, Cu2+, and Zn2+) through colorimetric or fluorescent analyses. L could recognize the target ions in solutions containing a wide range of other cations and anions. The recognition mechanisms were verified with a Job's plot, HR-MS assays, and 1H NMR titration experiments. Then, L was employed to develop colorimetric test strips and TLC plates for Co2+. Meanwhile, L was capable of quantitatively measuring the amount of target ions in tap water and river water samples. Notably, L was used for imaging Zn2+ in HepG2 cells, zebrafish, and tumor-bearing mice, which demonstrated its potential biological applications. Therefore, L can probably serve as a versatile tool for the detection of the target metal ions in environmental and biological applications.

Synthesis of a New Phenyl Chlormethine-Quinazoline Derivative, a Potential Anti-Cancer Agent, Induced Apoptosis in Hepatocellular Carcinoma Through Mediating Sirt1/Caspase 3 Signaling Pathway.

Quinazoline derivatives display multiple pharmacological activities and target various biological receptors. Based on the skeleton of quinazoline core, we designed and synthesized three new quinazoline-phenyl chlormethine conjugates (I-III) bearing a Schiff base (C = N) linker, and investigated their anti-tumor effects on HepG2-xenografted tumor and human cancer cell line HepG2. Among these compounds, compound II showed better inhibitory effect against HepG2 cells. In the present study, TUNEL staining, western blot, molecular docking, and siRNA were used to investigate the inhibitory mechanism of compound II towards hepatoma. Compound II inhibited HepG2-xenografted tumor growth in nude mice. Moreover, Compound II not only up-regulated Bax/Bcl-2 ratio and active-caspase 3 level, but also down-regulated Sirt1 expression and its activity, as well as PGC-1α expression. Furthermore, compound II also significantly suppressed the promotion of HepG2 cell proliferation, as evidenced by MTT assay and lactate dehydrogenase (LDH) release assay. Of note, the cytotoxicity of Compound II on HepG2 cells mainly via regulating Sirt1/caspase 3 signaling pathway, consisting with the results in vivo. Intriguingly, z-DEVD-FMK, a caspase 3 inhibitor, almost abolished the inhibitory effects of compound II. Of note, knockdown of caspase 3 by siRNA significantly reversed the inhibitory effect of compound II on HepG2. Interestingly, compound II directly bonded to Sirt1, indicating that Sirt1 might be a promising therapeutic target of compound II. In summary, our findings reveal that compound II, a new synthetical phenyl chlormethine-quinazoline derivative, contributes to the apoptosis of HepG2 cells both in vivo and in vitro through mediating Sirt1/caspase 3 singling pathway. These findings demonstrate that compound II may be a new potent agent against hepatocellular carcinoma.