Macrophage-reprogramming upconverting nanoparticles for enhanced TAM-mediated antitumor therapy of hypoxic breast cancer

In an attempt to achieve antitumor effects by switching the phenotype of macrophages from the tumor-promoting M2 type to the tumor-suppressing M1 type, we fabricated mannose-decorated/macrophage membrane-coated, silica-layered NaErF4@NaLuF4 upconverting nanoparticles (UCNPs) co-doped with perfluorocarbon (PFC)/chlorin e6 (Ce6) and loaded with paclitaxel (PTX) (UCNP@mSiO2-PFC/Ce6@RAW-Man/PTX: ∼61 nm; -11.6 mV). These nanoparticles were designed to have two major functionalities, (i) efficient singlet oxygen generation aided by an oxygen supply and (ii) good targeting to tumor-associated macrophage (TAMs) (M2-type), to induce polarization to M1 type macrophages that release proinflammatory cytokines and suppress breast cancers. The primary UCNPs consisted of lanthanide elements (erbium and lutetium) in a core@shell structure, and they facilely emitted 660 nm light in response to a deep-penetrating 808 nm near-infrared laser. Moreover, the UCNPs@mSiO2-PFC/Ce6@RAW-Man/PTX were able to release O2 and generate 1O2 because of the co-doped PFC/Ce6 and upconversion. Our nanocarriers' excellent uptake to RAW 264.7 macrophage cells (M2 type) and efficient M1-type polarization activity were clearly demonstrated using qRT-PCR and immunofluorescence-based confocal laser scanning microscopy. Our nanocarriers displayed significant cytotoxicity to 4T1 cells in 2D culture and 3D co-culture systems of 4T1/RAW 264.7 cells. More importantly, UCNPs@mSiO2-PFC/Ce6@RAW-Man/PTX (+808 nm laser) noticeably suppressed tumor growth in 4T1-xenografted mice, compared with the other treatment groups (332.4 vs. 709.5-1185.5 mm3). We attribute this antitumor efficacy to the prominent M1-type macrophage polarization caused by our nanocarriers through efficient ROS/O2 generation and targeting of M2-type TAMs via mannose ligands on coated macrophage-membrane.

Upconverting nanoparticle-containing erythrocyte-sized hemoglobin microgels that generate heat, oxygen and reactive oxygen species for suppressing hypoxic tumors

Inspired by erythrocytes that contain oxygen-carrying hemoglobin (Hb) and that exhibit photo-driven activity, we introduce homogenous-sized erythrocyte-like Hb microgel (μGel) systems (5–6 μm) that can (i) emit heat, (ii) supply oxygen, and (iii) generate reactive oxygen species (ROS; ¹O₂) in response to near-infrared (NIR) laser irradiation. Hb μGels consist of Hb, bovine serum albumin (BSA), chlorin e6 (Ce6) and erbium@lutetium upconverting nanoparticles (UCNPs; ∼35 nm) that effectively convert 808 nm NIR light to 660 nm visible light. These Hb μGels are capable of releasing oxygen to help generate sufficient reactive oxygen species (¹O₂) from UCNPs/Ce6 under severely hypoxic condition upon NIR stimulation for efficient photodynamic activity. Moreover, the Hb μGels emit heat and increase surface temperature due to NIR light absorption by heme (iron protoporphyrin IX) and display photothermal activity. By changing the Hb/UCNP/Ce6 ratio and controlling the amount of NIR laser irradiation, it is possible to formulate bespoke Hb μGels with either photothermal or photodynamic activity or both in the context of combined therapeutic effect. These Hb μGels effectively suppress highly hypoxic 4T1 cell spheroid growth and xenograft mice tumors in vivo.

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Erythrocyte-like hemoglobin μGels are prepared with upconverting nanoparticles.

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The μGels respond to the 808 nm near-infrared laser irradiation.

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The μGels emit heat, supply oxygen, and generate reactive oxygen species.

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The μGels have combined photothermal and photodynamic activity.

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The μGels suppress the growth of severe hypoxic 4T1 xenograft tumors.

Amplified Fenton-Based Oxidative Stress Utilizing Ultraviolet Upconversion Luminescence-Fueled Nanoreactors for Apoptosis-Strengthened Ferroptosis Anticancer Therapy

As an emerging anticancer strategy, ferroptosis has recently been developed in combination with current therapeutic modalities to overcome the existing limitations of conventional therapies. Herein, an ultraviolet (UV) upconversion luminescence-fueled nanoreactor is explored to combine ferroptosis and apoptosis through the UV-catalyzed Fenton reaction of an iron supplement (ferric ammonium citrate) loaded in a mesoporous silica layer in addition to the support of a chemotherapeutic agent (cisplatin) attached on the functionalized silica surface for the treatment of triple negative breast cancer (TNBC). The nanoplatform can circumvent the low penetration depth typical of UV light by upconverting near-infrared irradiation and emitting UV photons that convert Fe³⁺ to Fe²⁺ to boost the generation of hydroxyl radicals (·OH), causing devastating lipid peroxidation. Apart from DNA damage-induced apoptosis, cisplatin can also catalyze Fenton-based therapy by its abundant production of hydrogen peroxide (H₂O₂). As a bioinspired lipid membrane, the folate receptor-targeted liposome as the coating layer offers high biocompatibility and colloidal stability for the upconversion nanoparticles, in addition to prevention of the premature release of encapsulated hydrophilic compounds, before driving the nanoformulation to the target tumor site. As a result, superior antitumor efficacy has been observed in a 4T1 tumor-bearing mouse model with negligible side effects, suggesting that such a nanoformulation could play a pivotal role in effective apoptosis-strengthened ferroptosis TNBC therapy.

Combined phototherapy with metabolic reprogramming-targeted albumin nanoparticles for treating breast cancer

Triple-negative breast cancer (TNBC) is characterized by rapid tumor growth and resistance to cancer therapy, and has a poor prognosis. Accumulating data have revealed that cancer metabolism relies on both the Warburg effect and oxidative phosphorylation (OXPHOS), which are strongly related to the high proliferation and chemoresistance of cancer cells. Phototherapy is considered as a non-invasive method to precisely control drug activity with reduced side effects. Herein, our group introduced an Abraxane-like nanoplatform, named LCIR NPs, which significantly eradicates cancer cells via synergism between metabolic reprogramming and phototherapy effects. Endowed with mitochondria-targeting residues, the nanoparticles efficiently inhibited mitochondrial complexes I and IV as well as hexokinase II, leading to the depletion of intracellular ATP. Consequently, the photodynamic and photothermal effect triggered by NIR irradiation was enhanced due to the alleviation of hypoxia and the thermoresistance mechanism that rely on mitochondrial metabolism. In vivo experiments showed that the tumor size of mice that received the combination treatment was only 50.7 mm³, which was 21 times smaller than that of the untreated group and was much lower than those of other single treatments after 21 days. Additionally, almost no systemic undesired toxicity was detected during the observation period. We believe that the concept of LCIR as presented here offers a potential platform to overcome the resistance to conventional therapies by the incorporation with the energy metabolism inhibition approach.

Combined Antitumor Therapy Using In Situ Injectable Hydrogels Formulated with Albumin Nanoparticles Containing Indocyanine Green, Chlorin e6, and Perfluorocarbon in Hypoxic Tumors

Combined therapy using photothermal and photodynamic treatments together with chemotherapeutic agents is considered one of the most synergistic treatment protocols to ablate hypoxic tumors. Herein, we sought to fabricate an in situ-injectable PEG hydrogel system having such multifunctional effects. This PEG hydrogel was prepared with (i) nab^TM-technique-based paclitaxel (PTX)-bound albumin nanoparticles with chlorin-e6 (Ce6)-conjugated bovine serum albumin (BSA-Ce6) and indocyanine green (ICG), named ICG/PTX/BSA-Ce6-NPs (~175 nm), and (ii) an albumin-stabilized perfluorocarbon (PFC) nano-emulsion (BSA-PFC-NEs; ~320 nm). This multifunctional PEG hydrogel induced moderate and severe hyperthermia (41−42 °C and >48 °C, respectively) at the target site under two different 808 nm laser irradiation protocols, and also induced efficient singlet oxygen (¹O₂) generation under 660 nm laser irradiation supplemented by oxygen produced by ultrasound-triggered PFC. Due to such multifunctionality, our PEG hydrogel formula displayed significantly enhanced killing of three-dimensional 4T1 cell spheroids and also suppressed the growth of xenografted 4T1 cell tumors in mice (tumor volume: 47.7 ± 11.6 and 63.4 ± 13.0 mm³ for photothermal and photodynamic treatment, respectively, vs. PBS group (805.9 ± 138.5 mm³), presumably based on sufficient generation of moderate heat as well as ¹O₂/O₂ even under hypoxic conditions. Our PEG hydrogel formula also showed excellent hyperthermal efficacy (>50 °C), ablating the 4T1 tumors when the irradiation duration was extended and output intensity was increased. We expect that our multifunctional PEG hydrogel formula will become a prototype for ablation of otherwise poorly responsive hypoxic tumors.

Highly Red Light-Emitting Erbium- and Lutetium-Doped Core-Shell Upconverting Nanoparticles Surface-Modified with PEG-Folic Acid/TCPP for Suppressing Cervical Cancer HeLa Cells

Photodynamic therapy (PDT) combined with upconverting nanoparticles (UCNPs) are viewed together as an effective method of ablating tumors. After absorbing highly tissue-penetrating near-infrared (NIR) light, UCNPs emit a shorter wavelength light (~660 nm) suitable for PDT. In this study, we designed and prepared highly red fluorescence-emitting silica-coated core-shell upconverting nanoparticles modified with polyethylene glycol (PEG5k)-folic acid and tetrakis(4-carboxyphenyl)porphyrin (TCPP) (UCNPs@SiO2-NH2@FA/PEG/TCPP) as an efficient photodynamic agent for killing tumor cells. The UCNPs consisted of two simple lanthanides, erbium and lutetium, as the core and shell, respectively. The unique core-shell combination enabled the UCNPs to emit red light without green light. TCPP, folic acid, and PEG were conjugated to the outer silica layer of UCNPs as a photosensitizing agent, a ligand for tumor attachment, and a dispersing stabilizer, respectively. The prepared UCNPs of ~50 nm diameter and -34.5 mV surface potential absorbed 808 nm light and emitted ~660 nm red light. Most notably, these UCNPs were physically well dispersed and stable in the aqueous phase due to PEG attachment and were able to generate singlet oxygen (1O2) with a high efficacy. The HeLa cells were treated with each UCNP sample (0, 1, 5, 10, 20, 30 μg/mL as a free TCPP). The results showed that the combination of UCNPs@SiO2-NH2@FA/PEG/TCPP and the 808 nm laser was significantly cytotoxic to HeLa cells, almost to the same degree as naïve TCPP plus the 660 nm laser based on MTT and Live/Dead assays. Furthermore, the UCNPs@SiO2-NH2@FA/PEG/TCPP was well internalized into HeLa cells and three-dimensional HeLa spheroids, presumably due to the surface folic acid and small size in conjunction with endocytosis and the nonspecific uptake. We believe that our UCNPs@SiO2-NH2@FA/PEG/TCPP will serve as a new platform for highly efficient and deep-penetrating photodynamic agents suitable for various tumor treatments.

Indocyanine Green and Curcumin Co-Loaded Nano-Fireball-Like Albumin Nanoparticles Based on Near-Infrared-Induced Hyperthermia for Tumor Ablation

Background

Indocyanine green (ICG) has received considerable interest as a biocompatible organic photothermal agent, and curcumin (Cur) is considered an attractive natural chemopreventive and chemotherapeutic compound. However, the in vivo applicability of ICG and Cur is significantly restricted by their poor ability to target tumors and their extremely low solubility.

Materials and Methods

To address these problems, ICG/Cur-loaded albumin nanoparticles (ICG-BSA-Cur-NPs) based on the nab^TM (nanoparticle albumin-bound) technology were applied to neuroblastomas in vivo.

Results

The fabricated ICG-BSA-Cur-NPs were found to be spherical, ~150 nm in size and highly dispersible and stable in aqueous solution. Approximately 80% of the incorporated ICG and Cur were gradually released from the NPs over 48 h. All formulations of ICG-BSA-Cur-NPs (5~20 µg/mL) showed efficient hyperthermia profiles (up to 50–60°C within 5 min) in response to 808-nm NIR laser irradiation in vitro and in vivo. Notably, ICG-BSA-Cur-NPs illuminated with 808-nm laser irradiation (1.5 W/cm²) showed excellent cytotoxicity toward N2a cells in vitro and undisputable antitumor efficacy in N2a-xenografted mice in vivo, compared to other tested sample groups (tumor volumes for PBS, BSA-Cur-NPs, free ICG, and ICG-BSA-Cur-NPs groups were 1408.6 ± 551.9, 1190.6 ± 343.6, 888.6 ± 566.2, and 103.0 ± 111.3 mm³, respectively).

Conclusion

We demonstrate that these hyperthermal chemotherapeutic ICG-BSA-Cur-NPs have potential as a future brain tumor treatment.