IR-780-Albumin-Based Nanocarriers Promote Tumor Regression Not Only from Phototherapy but Also by a Nonirradiation Mechanism

Integration of 3D Fluorescence Imaging and Luminescent Thermometry with Core-Shell Engineered NaYF4:Nd3+/Yb3+/Ho3+ Nanoparticles

The design of rare-earth-doped upconversion/downshifting nanoparticles (NPs) for theoretical use in nanomedicine has garnered considerable interest. Previous research has emphasized luminescent nanothermometry and photothermal therapy, while three-dimensional (3D) near-infrared (NIR) luminescent tracers have received less attention. Our study introduces Nd3+-, Yb3+-, and Ho3+-doped NaYF4 core-shell luminescent NPs as potential multiparametric nanothermometers and NIR imaging tracers. Nd3+ sensitizes at 804 nm, while Yb3+ bridges to activators Ho3+. We evaluated the photoluminescence properties of Nd3+-, Yb3+-, and Ho3+-doped core and core-shell NPs synthesized via polyol-mediated and thermal decomposition methods. The NaYF4:NdYbHo(7/15/3%)@NaYF4:Nd(15%) core-shell NPs demonstrate competitive nanothermometry capabilities. Specifically, the polyol-synthesized sample exhibits a sensitivity of 0.27% K-1 at 313 K (40 °C), whereas the thermally decomposed synthesized sample shows a significantly higher sensitivity of 0.55% K-1 at 313 K (40 °C) in the near-infrared range. Control samples indicate back energy transfer processes from both Yb and Ho to Nd, while Yb to Ho energy transfer enhances Ho3+-driven upconversion transitions in green and red wavelengths, suggesting promise for photodynamic therapy. Fluorescence molecular tomography confirms 3D NIR fluorescence nanoparticle localization in a biological media after injection, highlighting the potential of core-shell NPs as NIR luminescent tracers. The strategy's clinical impact lies in photothermal treatment planning, leveraging core-shell NPs for (pre)clinical applications, and enabling the easy addition of new functionalities through distinct ion doping.

Tumor-activated targetable photothermal chemotherapy using IR780/zoledronic acid-containing hybrid polymeric nanoassemblies with folate modification to treat aggressive breast cancer

To effectively treat aggressive breast cancer by tumor-activated targetable photothermal chemotherapy, in this work, folate (FA)-modified hybrid polymeric nanoassemblies (HPNs) with a poly(ethylene glycol) (PEG)-detachable capability are developed as vehicles for tumor-targeted co-delivery of IR780, a lipophilic photothermal reagent, and zoledronic acid (ZA), a hydrophilic chemotherapy drug. Through hydrophobic interaction-induced co-assembly, IR780 molecules and ZA/poly(ethylenimine) (PEI) complexes were co-encapsulated into a poly(lactic-co-glycolic acid) (PLGA)-rich core stabilized by the amphiphilic FA-modified D-α-tocopheryl poly(ethylene glycol) succinate (FA-TPGS) and acidity-sensitive PEG-benzoic imine-octadecane (C18) (PEG-b-C18) conjugates. The developed FA-ZA/IR780@HPNs with high ZA and IR780 payloads not only showed excellent colloidal stability in a serum-containing milieu, but also promoted IR780-based photostability and photothermal conversion efficiency. Furthermore, for FA-ZA/IR780@HPNs under simulated physiological conditions, the premature leakage of IR780 and ZA molecules was remarkably declined. In a mimetic acidic tumor microenvironment, the uptake of FA-ZA/IR780@HPNs by FA receptor-overexpressed 4T1 breast cancer cells was remarkably promoted by PEG detachment combined with FA receptor-mediated endocytosis, thus effectively hindering migration of cancer cells and augmenting the anticancer efficacy of photothermal chemotherapy. Notably, the in vivo studies demonstrated that the FA-ZA/IR780@HPNs largely deposited at 4T1 tumor sites and profoundly suppressed tumor growth and metastasis without severe systemic toxicity upon near infrared (NIR)-triggered IR780-mediated hyperthermia integrated with ZA chemotherapy. This work presents a practical strategy to treat aggressive breast tumors with tumor-triggered targetable photothermal chemotherapy using FA-ZA/IR780@HPNs.

Immunogenic Cell Death Photothermally Mediated by Erythrocyte Membrane-Coated Magnetofluorescent Nanocarriers Improves Survival in Sarcoma Model

Inducing immunogenic cell death (ICD) during cancer therapy is a major challenge that might significantly improve patient survival. The purpose of this study was to develop a theranostic nanocarrier, capable both of conveying a cytotoxic thermal dose when mediating photothermal therapy (PTT) after its intravenous delivery, and of consequently inducing ICD, improving survival. The nanocarrier consists of red blood cell membranes (RBCm) embedding the near-infrared dye IR-780 (IR) and camouflaging Mn-ferrite nanoparticles (RBCm-IR-Mn). The RBCm-IR-Mn nanocarriers were characterized by size, morphology, surface charge, magnetic, photophysical, and photothermal properties. Their photothermal conversion efficiency was found to be size- and concentration-dependent. Late apoptosis was observed as the cell death mechanism for PTT. Calreticulin and HMGB1 protein levels increased for in vitro PTT with temperature around 55 °C (ablative regime) but not for 44 °C (hyperthermia), suggesting ICD elicitation under ablation. RBCm-IR-Mn were then intravenously administered in sarcoma S180-bearing Swiss mice, and in vivo ablative PTT was performed five days later. Tumor volumes were monitored for the subsequent 120 days. RBCm-IR-Mn-mediated PTT promoted tumor regression in 11/12 animals, with an overall survival rate of 85% (11/13). Our results demonstrate that the RBCm-IR-Mn nanocarriers are great candidates for PTT-induced cancer immunotherapy.

Cytotoxicities of Tumor-Seeking Dyes: Impact on Future Clinical Trials

Heptamethine (Cy7) dyes with meso-Cl substituents injected intravenously (iv) into mice accumulate in tumors and persist there over several days. We believe this occurs via meso-Cl displacement by the only free cysteine residues of albumin; therefore, conjugating tumor-seeking dyes with fragments can increase selective therapeutic delivery to tumors and drug residence. This strategy has elevated significance recently because the first tumor-seeking dye-drug conjugate has moved into clinical trials. Options for further clinical research include modifying the dye, and use of preformed albumin adducts instead of dyes alone. Herein we show correlations of cytotoxicities, lipophilicities, organelle localization, apoptosis, cell-cycle arrest, wound healing/migration assays, and reactivities/affinities with human serum albumin are difficult to observe. However, our studies arrived at an important conclusion: preformed dye-drug-HSA adducts are less cytotoxic, and therefore preferable for subsequent clinical work, relative to direct injection of meso-Cl-containing forms.

Photothermal Properties of IR-780-Based Nanoparticles Depend on Nanocarrier Design: A Comparative Study on Synthetic Liposomes and Cell Membrane and Hybrid Biomimetic Vesicles

Biomimetic nanoparticles hold great promise for photonic-mediated nanomedicine due to the association of the biological functionality of the membrane with the physical/chemical goals of organic/inorganic structures, but studies involving fluorescent biomimetic vesicles are still scarce. The purpose of this article is to determine how photothermal therapy (PTT) with theranostic IR-780-based nanoparticles depends on the dye content, cholesterol content, lipid bilayer phase and cell membrane type. The photophysical responses of synthetic liposomes, cell membrane vesicles and hybrid nanoparticles are compared. The samples were characterized by nanoparticle tracking analysis, photoluminescence, electron spin resonance, and photothermal- and heat-mediated drug release experiments, among other techniques. The photothermal conversion efficiency (PCE) was determined using Roper's method. All samples excited at 804 nm showed three fluorescence bands, two of them independent of the IR-780 content. Samples with a fluorescence band at around 850 nm showed photobleaching (PBL). Quenching was higher in cell membrane vesicles, while cholesterol inhibited quenching in synthetic liposomes with low dye content. PTT depended on the cell membrane and was more efficient for melanoma than erythrocyte vesicles. Synthetic liposomes containing cholesterol and a high amount of IR-780 presented superior performance in PTT experiments, with a 2.4-fold PCE increase in comparison with free IR-780, no PBL and the ability to heat-trigger doxorubicin release.

Albumin-based nanoparticle for dual-modality imaging of the lymphatic system

The lymphatic system is a complex network of lymphatic vessels, lymph nodes, and lymphoid organs. The current understanding of the basic mechanism and framework of the lymphatic system is relatively limited and not ideal for exploring the function of the lymphatic system, diagnosing lymphatic system diseases, and controlling tumor metastasis. Imaging modalities for evaluating lymphatic system diseases mainly include lymphatic angiography, reactive dye lymphatic angiography, radionuclide lymphatic angiography, computed tomography, and ultrasonography. However, these are insufficient for clinical diagnosis. Some novel imaging methods, such as magnetic resonance imaging, positron emission computed tomography, single-photon emission computed tomography, contrast-enhanced ultrasonography, and near-infrared imaging with agents such as cyanine dyes, can reveal lymphatic system information more accurately and in detail. We fabricated an albumin-based fluorescent probe for dual-modality imaging of the lymphatic system. A near-infrared cyanine dye, IR-780, was absorbed into bovine serum albumin (BSA), which was covalently linked to a molecule of diethylenetriaminepentaacetic acid to chelate gadolinium Gd3+. The fabricated IR-780@BSA@Gd3+ nanocomposite demonstrates strong fluorescence and high near-infrared absorption and can be used as a T1 contrast agent for magnetic resonance imaging. In vivo dual-modality fluorescence and magnetic resonance imaging showed that IR-780@BSA@Gd3+ rapidly returned to the heart through the lymphatic circulation after it was injected into the toe webs of mice, facilitating good lymphatic imaging. The successful fabrication of the new IR-780@BSA@Gd3+ nanocomposite will facilitate the study of the mechanism and morphological structure of the lymphatic system.

Liposomal Glucose Oxidase for Enhanced Photothermal Therapy and Photodynamic Therapy against Breast Tumors

Organic near-infrared fluorescent dye mediated photothermal therapy (PTT) and photodynamic therapy (PDT) suffer from heat shock response, since, heat shock proteins (HSPs) are overexpressed and can repair the proteins damaged by PTT and PDT. Starvation therapy by glucose oxide (GOx) can inhibit the heat shock response by limiting the energy supply. However, the delivery of sufficient and active GOx remains a challenge. To solve this problem, we utilize liposomes as drug carriers and prepare GOx loaded liposome (GOx@Lipo) with a high drug loading content (12.0%) and high enzymatic activity. The successful delivery of GOx shows excellent inhibition of HSPs and enhances PTT and PDT. Additionally, we apply the same liposome formulation to load near-infrared dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbo cyanine iodide (DiR) and prepare DiR contained liposomes (DiR@Lipo) for PTT and PDT. The liposomal formulation substantially enhances the PTT and PDT properties of DiR as well as the cellular uptake and tumor accumulation. Finally, the combination therapy shows excellent tumor inhibition on 4T1 tumor-bearing mice. Interestingly, we also find that the starvation therapy can efficiently inhibit tumor metastasis, which is probably due to the immunogenic effect. Our work presents a biocompatible and effective carrier for the combination of starvation therapy and phototherapy, emphasizing the importance of auxiliary starvation therapy against tumor metastasis and offering important guidance for clinical PTT and PDT.

Homologous targeting nanoparticles for enhanced PDT against osteosarcoma HOS cells and the related molecular mechanisms

BACKGROUND

No prominent advancements in osteosarcoma (OS) treatment have been made in the past 20 years. Although photodynamic therapy (PDT) is an emerging technique for cancer therapy, the lack of targeted photosensitizers for OS treatment severely limits its applications.

RESULTS

In this study, we constructed a potential theranostic nanoplatform by using (poly (lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) encapsulating IR780 into the shell (PLGA-IR780 NPs), which were further camouflaged with human OS cell membranes from the HOS cell line (MH-PLGA-IR780 NPs). These constructed NPs showed the capacity for homologous targeting with excellent photoacoustic (PA)/fluorescence (FL) imaging ability. Benefitting from their homologous targeting capacity, MH-PLGA-IR780 NPs obviously promoted cell endocytosis in vitro and tumor accumulation in vivo, which could further improve PDT performance under near-infrared (NIR) irradiation. In addition, to their homologous targeting and PA/FL dual-mode imaging ability, MH-PLGA-IR780 NPs had advantages in penetrating deeper into tumor tissues and in real-time dynamic distribution monitoring in vivo, which laid a foundation for further clinical applications in OS. Moreover, we demonstrated that PDT guided by the constructed NPs could significantly induce HOS cells apoptosis and ferroptosis via excessive accumulation of reactive oxygen species (ROS), and further determined that the potential anticancer molecular mechanism of apoptosis was triggered by the release of cytochrome c-activated mitochondrial apoptosis (endogenous apoptosis), and that ferroptosis caused the activation of nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy and the inactivation of glutathione peroxidase 4 (GPX4), synergistically leading to excessive accumulation of Lipid-ROS and Lipid peroxides (LPOs). Concurrently, MH-PLGA-IR780 NPs-guided PDT also showed an obvious inhibitory effect on tumor growth in vivo.

CONCLUSION

These results suggest that this homologous targeting-based theranostic nanoplatform provides an effective method to improve PDT performance in OS and contributes a new and promising approach for OS therapy.

Corona protein impacts on alternating current biosusceptometry signal and circulation times of differently coated MnFe2O4 nanoparticles

Background: We evaluated the impacts of corona protein (CP) formation on the alternating current biosusceptometry (ACB) signal intensity and in vivo circulation times of three differently coated magnetic nanoparticles (MNP): bare, citrate-coated and bovine serum albumin-coated MNPs. Methods: We employed the ACB system, gel electrophoresis and mass spectrometry analysis. Results: Higher CP formation led to a greater reduction in the in vitro ACB signal intensity and circulation time. We found fewer proteins forming the CP for the bovine serum albumin-coated MNPs, which presented the highest circulation time in vivo among the MNPs studied. Conclusion: These data showed better biocompatibility, stability and magnetic signal uniformity in biological media for bovine serum albumin-coated MNPs than for citrate-coated MNPs and bare MNPs.

Hows and Whys of Tumor-Seeking Dyes

Active targeting uses molecular fragments that bind receptors overexpressed on cell surfaces to deliver cargoes, and this selective delivery to diseased over healthy tissue is valuable in diagnostic imaging and therapy. For instance, targeted near-infrared (near-IR) dyes can mark tissue to be excised in surgery, and radiologists can use active targeting to concentrate agents for positron emission tomography (PET) in tumor tissue to monitor tumor metastases. Selective delivery to diseased tissue is also valuable in some treatments wherein therapeutic indexes (toxic/effective doses) are key determinants of efficacy. However, active targeting will only work for cells expressing the pivotal cell surface receptor that is targeted. That is a problem because tumors, even ones derived from the same organ, are not homogeneous, patient-to-patient variability is common, and heterogeneity can occur even in the same patient, so monotherapy with one actively targeted agent is unlikely to be uniformly effective. A particular category of fluorescent heptamethine cyanine-7 (Cy-7) dyes, here called tumor seeking dyes, offer a way to circumvent this problem because they selectively accumulate in any solid tumor. Furthermore, they persist in tumor tissue for several days, sometimes longer than 72 h. Consequently, tumor seeking dyes are near-IR fluorescent targeting agents that, unlike mAbs (monoclonal antibodies), accumulate in any solid lesion, thus overcoming tumor heterogeneity, and persist there for long periods, circumventing the rapid clearance problems that bedevil low molecular mass drugs. Small molecule imaging agents and drugs attached to tumor-seeking dyes have high therapeutic indices and long residence times in cancer cells and tumor tissue. All this sounds too good to be true. We believe most of this is true, but the controversy is associated with how and why these characteristics arise. Prior to our studies, the prevailing hypothesis, often repeated, was that tumor seeking dyes are uptaken by organic anion transporting polypeptides (OATPs) overexpressed on cancer cells. This Account summarizes evidence indicating tumor seeking Cy-7 dyes have exceptional accumulation and persistence properties because they covalently bind to albumin in vivo. That adduct formation provides a convenient way to form albumin-bound pharmaceuticals labeled with near-IR fluorophores which can be tracked in vivo. This understanding may facilitate more rapid developments of generally applicable actively targeted reagents.

Noninvasive intratumoral thermal dose determination during in vivo magnetic nanoparticle hyperthermia: combining surface temperature measurements and computer simulations

PURPOSE

Noninvasive thermometry during magnetic nanoparticle hyperthermia (MNH) remains a challenge. Our pilot study proposes a methodology to determine the noninvasive intratumoral thermal dose during MNH in the subcutaneous tumor model.

METHODS

Two groups of Ehrlich bearing-mice with solid and subcutaneous carcinoma, a control group (n = 6), and a MNH treated group (n = 4) were investigated. Histopathology was used to evaluate the percentage of non-viable lesions in the tumor. MNH was performed at 301 kHz and 17.5 kA.m^-1, using a multifunctional nanocarrier. Surface temperature measurements were obtained using an infrared camera, where an ROI with 750 pixels was used for comparison with computer simulations. Realistic simulations of the bioheat equation were obtained by combining histopathology intratumoral lesion information and surface temperature agreement of at least 50% of the pixel's temperature data calculated and measured at the surface.

RESULTS

One animal of the MNH group showed tumor recurrence, while two others showed complete tumor remission (monitored for 585 days). Sensitivity analysis of the simulation parameters indicated low tumor blood perfusion. Numerical simulations indicated, for the animals with complete remission, an irreversible tissue injury of 91 ± 5% and 100%, while the one with recurrence had a lower value, 56 ± 7%. The computer simulations also revealed the in vivo heat efficiency of the nanocarrier.

CONCLUSION

A new methodology for determining noninvasively the three-dimensional intratumoral thermal dose during MNH was developed. The method demonstrates the potential for predicting the long-term preclinical outcome of animals treated with MNH.

Photodynamic Nanophotosensitizers: Promising Materials for Tumor Theranostics

Photodynamic theranostics/therapy (PDT) is a potential strategy for selectively imaging malignant sites and treating cancer via a non-invasive therapeutic method. Photosensitizers, the crucial components of PDT, enable colocalization of photons and light, and photon/light therapy in the therapeutic window of 400-900 nm exhibits photocytotoxicity to tumor cells. Due to their high biostability and photocytotoxicity, nanophotosensitizers (NPSs) are of much interest for malignant tumor theranostics at present. NPS-activated photons transfer energy through the absorption of a photon and convert molecular oxygen to the singlet reactive oxygen species, which leads to apoptosis and necrosis. Moreover, NPSs modified by polymers, including PLGA, PEG-PLA, PDLLA, PVCL-g-PLA, and P(VCL-co-VIM)-g-PLA, exhibit excellent biocompatibility, and a tumor-targeting molecule linked on the nanoparticle surface can precisely deliver NPSs into the tumor region. The development of NPSs will accelerate the progress in tumor theranostics through the photon/light pathway.