MSOT-Guided Nanotheranostics for Synergistic Mild Photothermal Therapy and Chemotherapy to Boost Necroptosis/Apoptosis

Epigallocatechin-3-gallate at the nanoscale: a new strategy for cancer treatment

CONTEXT

Epigallocatechin-3-gallate (EGCG), the predominant catechin in green tea, has shown the potential to combat various types of cancer cells through its ability to modulate multiple signaling pathways. However, its low bioavailability and rapid degradation hinder its clinical application.

OBJECTIVE

This review explores the potential of nanoencapsulation to enhance the stability, bioavailability, and therapeutic efficacy of EGCG in cancer treatment.

METHODS

We searched the PubMed database from 2019 to the present, using 'epigallocatechin gallate', 'EGCG', and 'nanoparticles' as search terms to identify pertinent literature. This review examines recent nano-engineering technology advancements that encapsulate EGCG within various nanocarriers. The focus was on evaluating the types of nanoparticles used, their synthesis methods, and the technologies applied to optimize drug delivery, diagnostic capabilities, and therapeutic outcomes.

RESULTS

Nanoparticles improve the physicochemical stability and pharmacokinetics of EGCG, leading to enhanced therapeutic outcomes in cancer treatment. Nanoencapsulation allows for targeted drug delivery, controlled release, enhanced cellular uptake, and reduced premature degradation of EGCG. The studies highlighted include those where EGCG-loaded nanoparticles significantly inhibited tumor growth in various models, demonstrating enhanced penetration and efficacy through active targeting mechanisms.

CONCLUSIONS

Nanoencapsulation of EGCG represents a promising approach in oncology, offering multiple therapeutic benefits over its unencapsulated form. Although the results so far are promising, further research is necessary to fully optimize the design of these nanosystems to ensure their safety, efficacy, and clinical viability.

Construction of Methotrexate-Loaded Bi2S3 Coated with Fe/Mn-Bimetallic Doped ZIF-8 Nanocomposites for Cancer Treatment Through the Synergistic Effects of Photothermal/Chemodynamic/Chemotherapy

A combination of therapeutic modalities in a single nanostructure is crucial for a successful cancer treatment. Synergistic photothermal therapy (PTT) can enhance the effects of chemodynamic therapy (CDT) and chemotherapy, which could intensify the therapeutic efficacy to induce cancer cell apoptosis. In this study, Fe and Mn on a zeolitic imidazolate framework (ZIF-8) (Fe/Mn-ZIF-8; FMZ) were synthesized through ion deposition. Furthermore, bismuth sulfide nanorods (Bi2S3 NRs; BS NRs) were synthesized via a hydrothermal process and coated onto FMZ to generate the core-shell structure of the Bi2S3@FMZ nanoparticles (B@FMZ). Next, methotrexate (MTX) was loaded effectively onto the porous surface of ZIF-8 to form the B@FMZ/MTX nanoparticles. The Fenton-like reaction catalyzes Fe2+/Mn2+ ions by decomposing H2O2 in the tumor microenvironment, resulting in the formation of toxic hydroxyl radicals (·OH), which promotes the CDT effect of killing cancer cells. Furthermore, under 808 nm laser irradiation, these B@FMZ nanoparticles showed a strong PTT effect, owing to the presence of intense BS NRs as a photothermal agent. The B@FMZ nanoparticles exhibited a prominent drug release efficiency of 87.25% at pH 5.5 under near-infrared laser irradiation due to the PTT effect can promote the drug delivery performance. The B@FMZ nanoparticles were subjected to dual-modal imaging, guided magnetic resonance imaging, and X-ray computed tomography imaging. Both in vitro and in vivo results suggested that the B@FMZ/MTX nanoparticles exhibited enhanced antitumor effects through the combined therapeutic effects of PTT, CDT, and chemotherapy. Therefore, these nanoparticles exhibit good biocompatibility and are promising candidates for cancer treatment.

A Diketopyrrolopyrrole-Based All-in-One Nanoplatform for Self-Reinforcing Mild Photothermal Therapy Cascade Immunotherapy for Tumors

Mild photothermal therapy (PTT) has attracted attention for effectively avoiding the severe side effects associated with high-temperature tumor ablation. However, its progress is hindered by the limited availability of high-performance photothermal agents (PTAs) and the thermoresistance of cancer cells induced by heat shock reactions. Herein, this work proposes a new strategy to expand the library of high-performance organic small-molecule PTAs and utilize it to construct a multifunctional nano-theranostic platform. By incorporating additional acceptors and appropriate π-bridges, a diketopyrrolopyrrole-based dye BDB is developed, which exhibits strong absorption and bright fluorescence emission in the near-infrared (NIR) region. Subsequently, BDB is co-coated with the heat shock protein (HSP) inhibitor tanespimycin (17-AAG) using the functional amphiphilic polymers DSPE-Hyd-PEG2000-cRGD to form an all-in-one nanoplatform BAG NPs. As a result, BAG NPs can precisely target tumor tissue, guide the treatment process in real-time through NIR-II fluorescence/photoacoustic/photothermal imaging, and release 17-AAG on demand to enhance mild PTT. Additionally, the mild PTT has been demonstrated to induce immunogenic cell death (ICD) and activate a systemic anti-tumor immune response, thereby suppressing both primary and distant tumors. Overall, this study presents a multifunctional nanoplatform designed for precise mild PTT combined with immunotherapy for effective tumor treatment.

PARP inhibitor boost the efficacy of photothermal therapy to TNBC through enhanced DNA damage and inhibited homologous recombination repair

Triple-negative breast cancer (TNBC) could benefit from PARP inhibitors (PARPi) for their frequent defective homologous recombination repair (HR). However, the efficacy of PARPi is limited by their lower bioavailability and high susceptibility to drug resistance, so it often needs to be combined with other treatments. Herein, polydopamine nanoparticles (PDMN) were constructed to load Olaparib (AZD) as two-channel therapeutic nanoplatforms. The PDMN has a homogeneous spherical structure around 100 nm and exhibits a good photothermal conversion efficiency of 62.4%. The obtained AZD-loaded nanoplatform (PDMN-AZD) showed enhanced antitumor effects through the combination of photothermal therapy (PTT) and PARPi. By western blot and flow cytometry, we found that PTT and PARPi could exert synergistic antitumor effects by further increasing DNA double-strand damage (DSBs) and enhancing HR defects. The strongest therapeutic effect of PDMN-AZD was observed in a BRCA-deficient mouse tumor model. In conclusion, the PDMN-AZD nanoplatform designed in this study demonstrated the effectiveness of PTT and PARPi for synergistic treatment of TNBC and preliminarily explained the mechanism.

Spatiotemporal Regulation of Cell Fate in Living Systems Using Photoactivatable Artificial DNA Membraneless Organelles

Coacervates formed by liquid-liquid phase separation emerge as important biomimetic models for studying the dynamic behaviors of membraneless organelles and synchronously motivating the creation of smart architectures with the regulation of cell fate. Despite continuous progress, it remains challenging to balance the trade-offs among structural stability, versatility, and molecular communication for regulation of cell fate and systemic investigation in a complex physiological system. Herein, we present a self-stabilizing and fastener-bound gain-of-function methodology to create a new type of synthetic DNA membraneless organelle (MO) with high stability and controlled bioactivity on the basis of DNA coacervates. Specifically, long single-strand DNA generated by rolling circle amplification (RCA) is selected as the scaffold that assembles into membraneless coacervates via phase separation. Intriguingly, the as-formed DNA MO can recruit RCA byproducts and other components to achieve self-stabilization, nanoscale condensation, and function encoding. As a proof of concept, photoactivatable DNA MO is constructed and successfully employed for time-dependent accumulation and spatiotemporal management of cancer in a mouse model. This study offers new, important insights into synthetic membraneless organelles for the basic understanding and manipulation of important life processes.

Nanomaterials-based advanced systems for photothermal / photodynamic therapy of oral cancer

The traditional clinical approaches for oral cancer consist of surgery, chemotherapy, radiotherapy, immunotherapy, and so on. However, these treatments often induce side effects and exhibit limited efficacy. Photothermal therapy (PTT) emerges as a promising adjuvant treatment, utilizing photothermal agents (PTAs) to convert light energy into heat for tumor ablation. Another innovative approach, photodynamic therapy (PDT), leverages photosensitizers (PSs) and specific wavelength laser irradiation to generate reactive oxygen species (ROS), offering an effective and non-toxic alternative. The relevant combination therapies have been reported in the field of oral cancer. Simultaneously, the advancement of nanomaterials has propelled the clinical application of PTT and PDT. Therefore, a comprehensive understanding of PTT and PDT is required for better application in oral cancer treatment. Here, we review the use of PTT and PDT in oral cancer, including noble metal materials (e.g., Au nanoparticles), carbon materials (e.g., graphene oxide), organic dye molecules (e.g., indocyanine green), organic molecule-based agents (e.g., porphyrin-analog phthalocyanine) and other inorganic materials (e.g., MXenes), exemplify the advantages and disadvantages of common PTAs and PSs, and summarize the combination therapies of PTT with PDT, PTT/PDT with chemotherapy, PTT with radiotherapy, PTT/PDT with immunotherapy, and PTT/PDT with gene therapy in the treatment of oral cancer. The challenges related to the PTT/PDT combination therapy and potential solutions are also discussed.

Nano-injectable pH/NIR-responsive hydrogel for chemo-photothermal synergistic drug delivery

Conventional cancer treatments are highly toxic and ineffective; therefore, it is essential to develop less toxic and minimally invasive treatment methods. A pH/Near Infra-red (NIR) dual-responsive, nano-injectable smart hydrogel was fabricated by incorporating CuS nanoparticles into the hydrogel networks formed by a random copolymer of N-isopropylacrylamide (NIPAM) and double-bond functionalized uracil. Microstructural characterizations of synthesized polymer and hydrogels were carried out using transmission electron microscope (TEM), scanning electron microscope (SEM), nuclear magnetic resonance (NMR) and fourier transform infrared spectroscopy (FT-IR). Multiple hydrogen bonding interactions between uracils function as physical cross-linking points to construct the network structure of the polymeric nanogel without the addition of additional cross-linking agents, ensuring the material's safety. The amino group on the structure of uracil gives the uracil-modified polymeric hydrogel excellent pH responsiveness. Notably, as a temperature-responsive material, poly (N-isopropylacrylamide) (PNIPAM) nanogel solution can achieve in situ gel formation (within 100 s at 37°C) above its lower critical solution temperature (LCST), granting injectability to polymeric solutions. Moreover, using a hierarchical construction strategy, the variable loading of DOX and CuS was achieved. First, a heterogeneous system was created by encapsulating doxorubicin (DOX) inside the nanogel via hydrophobic and π-π stacking interactions, followed by the introduction of CuS nanoparticles as photosensitizers outside of the nanogels. Due to the presence of CuS nanoparticles, the gel is able to convert NIR light into local heat to enhance the destruction of tumor cells while simultaneously achieving rapid in situ gel formation. The in situ-forming hydrogel showed promising tissue biocompatibility. The in vitro antitumor test demonstrated the capacity of the nanocomposite hydrogel for chemo-photothermal synergistic therapy. Therefore, this prepared platform has the potential to become a safe and effective, smart-responsive drug carrier for chemotherapy and PTT synergy, a minimally invasive material for tumor treatment.

Tumor Microenvironment Activated Photoacoustic-Fluorescence Bimodal Nanoprobe for Precise Chemo-immunotherapy and Immune Response Tracing of Glioblastoma

Synergistic therapy strategy and prognostic monitoring of glioblastoma's immune response to treatment are crucial to optimize patient care and advance clinical outcomes. However, current systemic temozolomide (TMZ) chemotherapy and imaging methods for in vivo tracing of immune responses are inadequate. Herein, we report an all-in-one theranostic nanoprobe (PEG/αCD25-Cy7/TMZ) for precise chemotherapy and real-time immune response tracing of glioblastoma by photoacoustic-fluorescence imaging. The nanoprobe was loaded with TMZ and targeted regulatory T lymphocyte optical dye αCD25-Cy7 encapsulated by glutathione-responsive DSPE-SS-PEG2000. The results showed that the targeted efficiency of the nanoprobe to regulatory T lymphocytes is up to 92.3%. The activation of PEG/αCD25-Cy7/TMZ by glutathione enhanced the precise delivery of TMZ to the tumor microenvironment for local chemotherapy and monitored glioblastoma's boundary by photoacoustic-fluorescence imaging. Immunotherapy with indoleamine 2,3-dioxygenase inhibitors after chemotherapy could promote immunological responses and reduce regulatory T lymphocyte infiltration, which could improve the survival rate. Photoacoustic imaging has in real-time and noninvasively depicted the dynamic process of immune response on a micrometer scale, showing that the infiltration of regulatory T lymphocytes after chemotherapy was up-regulated and would down-regulate after IDO inhibitor treatment. This all-in-one theranostic strategy is a promising method for precisely delivering TMZ and long-term dynamically tracing regulatory T lymphocytes to evaluate the immune response in situ for accurate tumor chemo-immunotherapy.

DNA Damage Inducer Mitoxantrone Amplifies Synergistic Mild-Photothermal Chemotherapy for TNBC via Decreasing Heat Shock Protein 70 Expression

Patients with triple-negative breast cancer (TNBC) have the worst clinical outcomes when compared to other subtypes of breast cancer. Nanotechnology-assisted photothermal therapy (PTT) opens new opportunities for precise cancer treatment. However, thermoresistance caused by PTT, as well as uncertainty in the physiological metabolism of existing phototherapeutic nanoformulations, severely limit their clinical applications. Herein, based on the clinically chemotherapeutic drug mitoxantrone (MTO), a multifunctional nanoplatform (MTO-micelles) is developed to realize mutually synergistic mild-photothermal chemotherapy. MTO with excellent near-infrared absorption (≈669 nm) can function not only as a chemotherapeutic agent but also as a photothermal transduction agent with elevated photothermal conversion efficacy (ƞ = 54.62%). MTO-micelles can accumulate at the tumor site through the enhanced permeability and retention effect. Following local near-infrared irradiation, mild hyperthermia (<50 °C) assists MTO in binding tumor cell DNA, resulting in chemotherapeutic sensitization. In addition, downregulation of heat shock protein 70 (HSP70) expression due to enhanced DNA damage can in turn weaken tumor thermoresistance, boosting the efficacy of mild PTT. Both in vitro and in vivo studies indicate that MTO-micelles possess excellent synergetic tumor inhibition effects. Therefore, the mild-photothermal chemotherapy strategy based on MTO-micelles has a promising prospect in the clinical transformation of TNBC treatment.

Mild photothermal/radiation therapy potentiates ferroptosis effect for ablation of breast cancer via MRI/PA imaging guided all-in-one strategy

BACKGROUND

Nanotheranostics advances anticancer management by providing therapeutic and diagnostic functions, that combine programmed cell death (PCD) initiation and imaging-guided treatment, thus increasing the efficacy of tumor ablation and efficiently fighting against cancer. However, mild photothermal/radiation therapy with imaging-guided precise mediating PCD in solid tumors, involving processes related to apoptosis and ferroptosis, enhanced the effect of breast cancer inhibition is not fully understood.

RESULTS

Herein, targeted peptide conjugated gold nano cages, iRGD-PEG/AuNCs@FePt NPs ternary metallic nanoparticles (Au@FePt NPs) were designed to achieve photoacoustic imaging (PAI)/Magnetic resonance imaging (MRI) guided synergistic therapy. Tumor-targeting Au@FePt forms reactive oxygen species (ROS), initiated by X-ray-induced dynamic therapy (XDT) in collaboration with photothermal therapy (PTT), inducing ferroptosis-augmented apoptosis to realize effective antitumor therapeutics. The relatively high photothermal conversion ability of Au@FePt increases the temperature in the tumor region and hastens Fenton-like processes to achieve enhanced synergistic therapy. Especially, RNA sequencing found Au@FePt inducting the apoptosis pathway in the transcriptome profile.

CONCLUSION

Au@FePt combined XDT/PTT therapy activate apoptosis and ferroptosis related proteins in tumors to achieve breast cancer ablation in vitro and in vivo. PAI/MRI images demonstrated Au@FePt has real-time guidance for monitoring synergistic anti-cancer therapy effect. Therefore, we have provided a multifunctional nanotheranostics modality for tumor inhibition and cancer management with high efficacy and limited side effects.

Nanotechnological strategies to increase the oxygen content of the tumor

Hypoxia is a negative prognostic indicator of solid tumors, which not only changes the survival state of tumors and increases their invasiveness but also remarkably reduces the sensitivity of tumors to treatments such as radiotherapy, chemotherapy and photodynamic therapy. Thus, developing therapeutic strategies to alleviate tumor hypoxia has recently been considered an extremely valuable target in oncology. In this review, nanotechnological strategies to elevate oxygen levels in tumor therapy in recent years are summarized, including (I) improving the hypoxic tumor microenvironment, (II) oxygen delivery to hypoxic tumors, and (III) oxygen generation in hypoxic tumors. Finally, the challenges and prospects of these nanotechnological strategies for alleviating tumor hypoxia are presented.

Mn3 O4 Nanoshell Coated Metal-Organic Frameworks with Microenvironment-Driven O2 Production and GSH Exhaustion Ability for Enhanced Chemodynamic and Photodynamic Cancer Therapies

Nanomedicine exhibits emerging potentials to deliver advanced therapeutic strategies in the fight against triple-negative breast cancer (TNBC). Nevertheless, it is still difficult to develop a precise codelivery system that integrates highly effective photosensitizers, low toxicity, and hydrophobicity. In this study, PCN-224 is selected as the carrier to enable effective cancer therapy through light-activated reactive oxygen species (ROS) formation, and the PCN-224@Mn₃ O₄ @HA is created in a simple one-step process by coating Mn₃ O₄ nanoshells on the PCN-224 template, which can then be used as an "ROS activator" to exert catalase- and glutathione peroxidase-like activities to alleviate tumor hypoxia while reducing tumor reducibility, leading to improved photodynamic therapeutic (PDT) effect of PCN-224. Meanwhile, Mn²⁺ produced cytotoxic hydroxyl radicals (∙OH) via the Fenton-like reaction, thus producing a promising spontaneous chemodynamic therapeutic (CDT) effect. Importantly, by remodeling the tumor microenvironment (TME), Mn₃ O₄ nanoshells downregulated hypoxia-inducible factor 1α expression, inhibiting tumor growth and preventing tumor revival. Thus, the developed nanoshells, via light-controlled ROS formation and multimodality imaging abilities, can effectively inhibit tumor proliferation through synergistic PDT/CDT, and prevent tumor resurgence by remodeling TME.

Research Progress of Nanomedicine-Based Mild Photothermal Therapy in Tumor

With the booming development of nanomedicine, mild photothermal therapy (mPTT, 42-45°C) has exhibited promising potential in tumor therapy. Compared with traditional PTT (>50°C), mPTT has less side effects and better biological effects conducive to tumor treatment, such as loosening the dense structure in tumor tissues, enhancing blood perfusion, and improving the immunosuppressive microenvironment. However, such a relatively low temperature cannot allow mPTT to completely eradicate tumors, and therefore, substantial efforts have been conducted to optimize the application of mPTT in tumor therapy. This review extensively summarizes the latest advances of mPTT, including two sections: (1) taking mPTT as a leading role to maximize its effect by blocking the cell defense mechanisms, and (2) regarding mPTT as a supporting role to assist other therapies to achieve synergistic antitumor curative effect. Meanwhile, the special characteristics and imaging capabilities of nanoplatforms applied in various therapies are discussed. At last, this paper puts forward the bottlenecks and challenges in the current research path of mPTT, and possible solutions and research directions in future are proposed correspondingly.

Recent advances in photothermal therapy-based multifunctional nanoplatforms for breast cancer

Breast cancer (BC) is one of the most common cancers in women worldwide; however, the successful treatment of BC, especially triple-negative breast cancer (TNBC), remains a significant clinical challenge. Recently, photothermal therapy (PTT), which involves the generation of heat under irradiation to achieve photothermal ablation of BC with minimal invasiveness and outstanding spatial–temporal selectivity, has been demonstrated as a novel therapy that can overcome the drawbacks of chemotherapy or surgery. Significantly, when combining PTT with chemotherapy and/or photodynamic therapy, an enhanced synergistic therapeutic effect can be achieved in both primary and metastatic BC tumors. Thus, this review discusses the recent developments in nanotechnology-based photothermal therapy for the treatment of BC and its metastasis to provide potential strategies for future BC treatment.