Targeting the tumor microenvironment with amphiphilic near-infrared cyanine nanoparticles for potentiated photothermal immunotherapy

Breaking the barriers in effective and safe Toll-like receptor stimulation via nano-immunomodulators for potent cancer immunotherapy

Immunotherapy is an emerging strategy that awakens the intrinsic immune system for cancer treatment. Generally, successful immunotherapy of malignant tumours relies on the effective production of tumour-associated antigens and their lymph node delivery, antigen processing and presentation for T-cell activation, and the dismantling of the immunosuppressive tumour microenvironment. Toll-like receptor (TLR) agonists are potent stimulants in cancer immunotherapy, which can directly activate antigen-presenting cells (APCs) and further induce T cell activation for antitumour immune response and convert immunosuppressive tumour microenvironment to an immunogenic one for cooperative tumour ablation. However, TLR agonists for effective cancer immunotherapy have encountered essential challenges, such as insufficient immune activation and systemic side effects. In recent years, nano-immunomodulators with TLR agonists have been employed for tumour- and/or lymph node-targeted immune activation to improve the antitumour immune response and alleviate their systemic toxicities, providing a promising strategy for enhanced cancer immunotherapy. Herein, we introduce the recent progress in developing various TLR nano-immunomodulators for cancer immunotherapy via APC activation and tumour microenvironment remodelling. Upon elucidating the rational design principles of nano-immunomodulators, we elucidate the advancement of TLR nanoagonists to break the barriers in effective and safe Toll-like receptor stimulation for potent cancer immunotherapy.

Cell membrane nanoparticles in cancer therapy: From basic structure to surface functionalization

Cell membrane nanoparticles (CNPs) have recently garnered significant attention as effective drug-delivery vehicles. Beyond their simple function of encapsulating cargo within a lipid bilayer structure, the cell membrane is a complex entity derived from biological materials, presenting a variety of surface proteins and glycans. Notable features that enhance their effectiveness as delivery vehicles include the inhibition of protein corona formation in the plasma and the suppression of macrophage phagocytosis, both of which contribute to prolonged blood circulation. Furthermore, CNPs exhibit homotypic targeting effects toward their cells of origin, resulting in reduced side effects, and because they are not xenobiotics, the likelihood of nonspecific immune activation is also minimized. This review focuses on various applications of CNPs in cancer therapeutic studies, examining their structural evolution and surface engineering developments. We introduce studies that leverage the inherent functionality of cell membranes and recent research in functional CNPs synthesized through genetic or chemical engineering methods. Through this review, we aim to trace the progression of CNP research, explore potential directions for their use in biomedical applications, and assess the prospects for clinical trials.

Exploring the mechanism of fibronectin extra domain B in the tumor microenvironment and implications for targeted immunotherapy and diagnostics (Review)

Fibronectin extra domain B (FN‑EDB) is a unique domain of FN), whose expression is significantly upregulated in the tumor microenvironment (TME). FN‑EDB plays a key role in tumor cell adhesion, angiogenesis and invasion, and is closely related to tumor malignancy and poor prognosis. Moreover, the high expression of FN‑EDB in multiple cancer types makes it a potential therapeutic target. However, comprehensive studies of the mechanism of FN‑EDB in different cancer types and its potential as therapeutic targets are lacking. The present study aimed to explore the general role of FN‑EDB in multiple types of cancer and to integrate the knowledge of cell biology, molecular biology and immunology, so as to give a comprehensive understanding of the role of FN‑EDB in TME. Furthermore, by focusing on the use of FN‑EDB in clinical diagnosis and treatment, the potential of targeting FN‑EDB as a diagnostic and therapeutic target was evaluated and the progress in clinical trials of these drugs was discussed. By searching web sites such as PubMed and web of science, various high‑quality studies including RNA sequencing, drug experiments, cell experiments, animal models, clinical randomized controlled experiments and large‑scale cohort studies were collected, with sufficient evidence to support a comprehensive evaluation of the function and potential application of FN‑EDB. The present study revealed the general role of FN‑EDB in multiple types of cancer and evaluated its potential as a diagnostic and therapeutic target. It also provided a basis for future development of more effective and precise cancer therapies.

Biomaterials enhancing localized cancer therapy activated anti-tumor immunity: a review

Localized cancer therapies such as radiotherapy, phototherapy, and chemotherapy are precise cancer treatment strategies aimed at minimizing systemic side effects. However, cancer metastasis remains the primary cause of mortality among cancer patients in clinical settings, and localized cancer treatments have limited efficacy against metastatic cancer. Therefore, researchers are exploring strategies that combine localized therapy with immunotherapy to activate robust anti-tumor immune responses, thereby eradicating metastatic cancer. Biomaterials, as novel materials, exhibit great potential in biomedical applications and have achieved great progress in clinic translation. This review introduces biomaterials and their applications in research focused on enhancing localized cancer treatment activated anti-tumor immunity. Additionally, the current challenges and future directions of biomaterials are also discussed, providing insights and references for related research.

Ultrathin BSA-Stabilized Black Phosphorous Nanoreactor Boosts Mild-Temperature Photothermal Therapy Through Modulation of Cellular Self-Defense Fate

Mild-temperature photothermal therapy (mild-PTT, 42-45 °C) offers a higher level of biosafety. However, its therapeutic effects are compromised by the heat shock response (HSR), a cellular self-defense mechanism, which triggers the overexpression of heat shock proteins (HSPs) with the capacity of repairing the damaged tumor cells. Herein, this work fabricates a novel nanoreactor by incorporating up-conversion nanoparticles (UCNPs), chlorin e6 (Ce6), and glucose oxidase (GOx) onto the ultrathin black phosphorus nanosheet (BPNS) (denoted as GOx-BUC). This nanoreactor amplifies mild-PTT effects under irradiation with an 808 nm laser, modulating HSPs-mediated cellular self-defense fate. On one hand, upon irradiation with a 980 nm laser, UCNPs can transfer energy to excite Ce6, leading to the generation of ROS burst, which achieves indiscriminate damage to HSPs activity in deeper tumor tissues. On the other hand, GOx can consume glucose, thereby depleting the ATP energy supply and further suppressing HSPs expression. Consequently, GOx-BUC exhibits excellent anti-tumor efficacy under mild temperature in a human colorectal cancer mouse model, resulting in complete tumor inhibition with negligible side effects. This black phosphorous nanoreactor, featuring dual-track HSPs destruction functionality, introduces novel perspectives for enhancing mild-PTT effectiveness while maintaining high biosafety.

Michael Addition-Based Neoadjuvant for Enhanced Cancer Immunotherapy

Cancer immunotherapy suffers from inefficient antigen presentation owing to the limited endocytosis of antigen by dendritic cells (DCs) and dysfunction of DCs in the immunosuppressive tumor microenvironment (ITME). Here, we revealed that cinnamaldehyde-grafted polyethylenimine (PC) held the potential to serve as a neoadjuvant to modulate the above processes and thus potentiate immune responses. The PC neoadjuvant could capture the tumor antigen generated during chemotherapy to enhance the crosstalk between the antigen and DCs. Then, it depleted the intracellular glutathione by the in situ Michael addition reaction, which not only activated the NOD-, LRR-, and pyrin domain-containing 3 (NLRP3) pathway to promote DCs maturation but also triggered the antigen release. As a result, it significantly augmented antigen presentation with a 46% ratio of DCs maturation and a 53% ratio of CD8+ T cell infiltration in low immunogenic murine breast cancer.

Immunological nanomaterials to combat cancer metastasis

Metastasis causes greater than 90% of cancer-associated deaths, presenting huge challenges for detection and efficient treatment of cancer due to its high heterogeneity and widespread dissemination to various organs. Therefore, it is imperative to combat cancer metastasis, which is the key to achieving complete cancer eradication. Immunotherapy as a systemic approach has shown promising potential to combat metastasis. However, current clinical immunotherapies are not effective for all patients or all types of cancer metastases owing to insufficient immune responses. In recent years, immunological nanomaterials with intrinsic immunogenicity or immunomodulatory agents with efficient loading have been shown to enhance immune responses to eliminate metastasis. In this review, we would like to summarize various types of immunological nanomaterials against metastasis. Moreover, this review will summarize a series of immunological nanomaterial-mediated immunotherapy strategies to combat metastasis, including immunogenic cell death, regulation of chemokines and cytokines, improving the immunosuppressive tumour microenvironment, activation of the STING pathway, enhancing cytotoxic natural killer cell activity, enhancing antigen presentation of dendritic cells, and enhancing chimeric antigen receptor T cell therapy. Furthermore, the synergistic anti-metastasis strategies based on the combinational use of immunotherapy and other therapeutic modalities will also be introduced. In addition, the nanomaterial-mediated imaging techniques (e.g., optical imaging, magnetic resonance imaging, computed tomography, photoacoustic imaging, surface-enhanced Raman scattering, radionuclide imaging, etc.) for detecting metastasis and monitoring anti-metastasis efficacy are also summarized. Finally, the current challenges and future prospects of immunological nanomaterial-based anti-metastasis are also elucidated with the intention to accelerate its clinical translation.

Radiation-based immunogenic vaccine combined with a macrophage "checkpoint inhibitor" for boosting innate and adaptive immunity against metastatic colon cancers

Immunogenic dying tumor cells hold promising prospects as cancer vaccines to activate systemic immunity against both primary and metastatic tumors. Especially, X-ray- induced dying tumor cells are rich in highly immunogenic tumor-associated antigens and self-generated dsDNA as potent adjuvants. However, we found that the X-ray induction process can result in the excessive exposure of phosphatidylserine in cancer vaccines, which can specifically bind with the MerTK receptor on macrophages, acting as a "checkpoint" to facilitate immune silence in the tumor microenvironment. Therefore, we developed a novel strategy combining X-ray-induced cancer vaccines with UNC2250, a macrophage MerTK "checkpoint inhibitor," for treating peritoneal carcinomatosis in colon cancer. By incorporating UNC2250 into the treatment regimen, immunosuppressive efferocytosis of macrophages, which relies on MerTK-directed recognition of phosphatidylserine on vaccines, was effectively blocked. Consequently, the immune analysis revealed that this combination strategy promoted the maturation of dendritic cells and M1-like repolarization of macrophages, thereby simultaneously eliciting robust adaptive and innate immunity. This innovative approach utilizing X-ray-induced vaccines combined with a checkpoint inhibitor may provide valuable insights for developing effective cancer vaccines and immunotherapies targeting colon cancer.

Sequence-Responsive Multifunctional Supramolecular Nanomicelles Act on the Regression of TNBC and Its Lung Metastasis via Synergic Pyroptosis-Mediated Immune Activation

Design of effective nanodrugs to modulate the immunosuppression of tumor microenvironment is a desirable approach to boost the clinical tumor-therapeutic effect. Supramolecular nanomicelles PolyMN-TO-8, which are constructed by self-assembling supramolecular host MTX-MPEG2000, guest NPX-2S, and TO-8 through hydrophobic forces, have excellent stability and responsiveness to carboxylesterase and glutathione in turn. In vivo studies validate that PolyMN-TO-8 enable to trigger pyroptosis-mediated immunogenic cell death under laser, avoiding the occurrence of immune dysregulation simultaneously. This therapeutic mode strengthens dendritic cells' maturation and accelerates the infiltration of CD8+ T cells into tumors through moderate activation of pro-inflammatory factors with elimination of immune-escape, ultimately making the tumor inhibition rate as high as 87.44% via synergistic functions of photodynamic therapy, photothermal therapy, chemotherapy, etc. The loss of immune-escape quickens the infiltration of CD8+ T cells into lungs, and further eschews the generation of tumor nodules in it. Chemotherapy, the release of interferon-γ, and immune memory effect also strengthen the defense against metastasis. The generation of O2 catalyzed by PolyMN-TO-8 under laser is indispensable for tumor metastasis inhibition undoubtedly.

NIR-II fluorescence and PA imaging guided activation of STING pathway in photothermal therapy for boosting cancer immunotherapy by theranostic thermosensitive liposomes

Photothermal immunotherapy has shown great potential for efficient cancer treatment. However, the immunosuppressive tumor microenvironment forms a heavy barrier for photothermal-induced anti-tumor immunity by inhibiting dendritic cell (DC) maturation and cytotoxic T cell response. Moreover, the lack of reliable spatiotemporal imaging modalities makes photothermal immunotherapy difficult to guide tumor ablation and monitor therapeutic outcomes in real time. Herein, we designed a theranostic thermosensitive liposome (PLDD) as a versatile nanoplatform to boost the adaptive anti-tumor immunity of photothermal immunotherapy and to achieve multiple bioimaging modalities in a real-time manner. PLDD contains two major functional components: a multifunctional photothermal agent (DTTB) and an immune potentiator STING pathway agonist (DMXAA). Upon irradiation, the heat generated by DTTB induced the immunogenic cell death (ICD) of the tumor and dissociated the structure of thermosensitive liposome to release DMXAA, which ultimately activated the STING pathway and promoted the ICD-induced immune response by increasing DC cell maturation and T cell recruitment. Moreover, the DTTB in PLDD displayed excellent second near-infrared (NIR-II) fluorescence and photoacoustic (PA) dual-modal imaging, which provided omnibearing information on the tumor and guided the subsequent therapeutic operation. Therefore, this versatile PLDD with light-triggered promotion of anti-tumor immunity and multiple spatiotemporal imaging profiles holds great potential for the future development of cancer immunotherapy.

Atomic vacancies-engineered ultrathin trimetallic nanozyme with anti-inflammation and antitumor performances for intestinal disease treatment

Colitis-associated colorectal cancer, which represents a highly aggressive subtypes of colorectal cancer, requires concurrent antitumor and anti-inflammation therapies in clinic. Herein, we successfully engineered Ru38Pd34Ni28 ultrathin trimetallic nanosheets (TMNSs) by introducing diverse transition metal atoms into the structure of RuPd nanosheets. Density functional theory (DFT) calculations reveal that the elaborate introduction of transition metal Ru and Ni facilitates the formation of Ru-O and Ni-O bonds on the surface of TMNSs for efficient reactive oxygen species (ROS) and reactive nitrogen species (RNS) scavenging, respectively. Moreover, the engineered abundant atomic vacancies on their surface conspicuously improve the performance in eliminating reactive oxygen and nitrogen species (RONS). The designed TMNSs act as a multi-metallic nanocatalyst with RONS elimination performance for chronic colitis treatment by relieving inflammation, as well as photothermal conversion capability for colon cancer therapy by inducing hyperthermia effect. Profiting from the excellent RONS scavenging activities, TMNSs can down-regulate the expression levels of the pro-inflammatory factors, thereby leading to prominent therapeutic efficacy against dextran sulfate sodium-induced colitis. Benefiting from the high photothermal performance, TMNSs cause significant suppression of CT-26 tumors without obvious recurrence. This work provides a distinct paradigm to design multi-metallic nanozymes for colon disease treatment by elaborate introduction of transition metal atoms and engineering of atomic vacancies.

Precision Delivery of Dual Immune Inhibitors Loaded Nanomodulator to Reverse Immune Suppression for Combinational Photothermal-Immunotherapy

Although photothermal therapy (PTT) can noninvasively kill tumor cells and exert synergistic immunological effects, the immune responses are usually harmed due to the lack of cytotoxic T cells (CTLs) pre-infiltration and co-existing of intricate immunosuppressive tumor microenvironment (TME), including the programmed cell death ligand 1 (PD-L1)/cluster of differentiation 47 (CD47)/regulatory T cells (Tregs)/M2-macrophages overexpression. Indoleamine 2, 3-dioxygenase inhibitor (NLG919) or bromodomain extra-terminal inhibitor (OTX015) holds great promise to reprogram suppressive TME through different pathways, but their collaborative application remains a formidable challenge because of the poor water solubility and low tumor targeting. To address this challenge, a desirable nanomodulator based on dual immune inhibitors loaded mesoporous polydopamine nanoparticles is designed. This nanomodulator exhibits excellent biocompatibility and water solubility, PTT, and bimodal magnetic resonance/photoacoustic imaging abilities. Owing to enhanced permeability and retention effect and tumor acidic pH-responsiveness, both inhibitors are precisely delivered and locally released at tumor sites. Such a nanomodulator significantly reverses the immune suppression of PD-L1/CD47/Tregs, promotes the activation of CTLs, regulates M2-macrophages polarization, and further boosts combined therapeutic efficacy, inducing a strong immunological memory. Taken together, the nanomodulator provides a practical approach for combinational photothermal-immunotherapy, which may be further broadened to other "immune cold" tumors.

Revealing the Effect of Photothermal Therapy on Human Breast Cancer Cells: A Combined Study from Mechanical Properties to Membrane HSP70

Hyperthermia-induced overexpression of heat shock protein 70 (HSP70) leads to the thermoresistance of cancer cells and reduces the efficiency of photothermal therapy (PTT). In contrast, cancer cell-specific membrane-associated HSP70 has been proven to activate antitumor immune responses. The dual effect of HSP70 on cancer cells inspires us that in-depth research of membrane HSP70 (mHSP70) during PTT treatment is essential. In this work, a PTT treatment platform for human breast cancer cells (MCF-7 cells) based on a mPEG-NH₂-modified polydopamine (PDA)-coated gold nanorod core-shell structure (GNR@PDA-PEG) is developed. Using the force-distance curve-based atomic force microscopy (FD-based AFM), we gain insight into the PTT-induced changes in the morphology, mechanical properties, and mHSP70 expression and distribution of individual MCF-7 cells with high-resolution at the single-cell level. PTT treatment causes pseudopod contraction of MCF-7 cells and generates a high level of intracellular reactive oxygen species, which severely disrupt the cytoskeleton, leading to a decrease in cellular mechanical properties. The adhesion maps, which are recorded by aptamer A8 functional probes using FD-based AFM, reveal that PTT treatment causes a significant upregulation of mHSP70 expression and it starts to exhibit a partial aggregation distribution on the MCF-7 cell surface. This work not only exemplifies that AFM can be a powerful tool for detecting changes in cancer cells during PTT treatment but also provides a better view for targeting mHSP70 for cancer therapy.

An enzyme-responsive and transformable PD-L1 blocking peptide-photosensitizer conjugate enables efficient photothermal immunotherapy for breast cancer

Mild photothermal therapy combined with immune checkpoint blockade has received increasing attention for the treatment of advanced or metastatic cancers due to its good therapeutic efficacy. However, it remains a challenge to facilely integrate the two therapies and make it potential for clinical translation. This work designed a peptide-photosensitizer conjugate (PPC), which consisted of a PD-L1 antagonist peptide (CVRARTR), an MMP-2 specific cleavable sequence, a self-assembling motif, and the photosensitizer Purpurin 18. The single-component PPC can self-assemble into nanospheres which is suitable for intravenous injection. The PPC nanosphere is cleaved by MMP-2 when it accumulates in tumor sites, thereby initiating the cancer-specific release of the antagonist peptide. Simultaneously, the nanospheres gradually transform into co-assembled nanofibers, which promotes the retention of the remaining parts within the tumor. In vivo studies demonstrated that PPC nanospheres under laser irradiation promote the infiltration of cytotoxic T lymphocytes and maturation of DCs, which sensitize 4T1 tumor cells to immune checkpoint blockade therapy. Therefore, PPC nanospheres inhibit tumor growth efficiently both in situ and distally and blocked the formation of lung metastases. The present study provides a simple and efficient integrated strategy for breast cancer photoimmunotherapy.

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A peptide-photosensitizer conjugate (PPC) with self-assembled ability.

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Self-assembled PPC realized enzyme-responsive PD-L1 blocking peptide release.

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Shape transformation from nanospheres to co-assembled nanofibers.

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Efficient integrated strategy for breast cancer photoimmunotherapy.

Reversing Immune Suppression and Potentiating Photothermal Immunotherapy via Bispecific Immune Checkpoint Inhibitor Loaded Hollow Polydopamine Nanospheres

Despite the great achievements of immune checkpoint blockade (ICB) therapy on programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) axis, ICB monotherapy still faces obstacles in eradicating solid tumors due to the lack of tumor-associated antigens or tumor-specific cytotoxicity. Photothermal therapy (PTT) is a potential therapeutic modality because it can noninvasively kill tumor cells by thermal ablation and generate both tumor-specific cytotoxicity and immunogenicity, which holds great feasibility to improve the efficiency of ICB by providing complementary immunomodulation. Except for the PD-1/PD-L1 axis, the cluster of differentiation 47 (CD47)/signal regulatory protein alpha (SIRPα) pathway has been considered as a novel strategy of tumor cells to evade the surveillance of macrophages and inactivate the immune response of PD-L1 blockade therapy. Therefore, it is necessary to synergize the antitumor effect of dual-targeting PD-L1 and CD47. Although promising, the application of PD-L1/CD47 bispecific antibodies, especially in combination with PTT, remains a formidable problem, due to the low objective response, activity loss at relatively high temperature, or nonvisualization. Herein, instead of using antibodies, we use MK-8628 (MK) to down-regulate both PD-L1 and CD47 simultaneously through halting the active transcription of oncogene c-MYC, leading to elicitation of the immune response. The hollow polydopamine (HPDA) nanospheres are introduced as a biocompatible nanoplatform with high loading capacity and magnetic resonance imaging (MRI) ability to deliver MK and induce PTT (HPDA@MK). Compared to preinjection, HPDA@MK exhibits the strongest MRI signal at 6 h postintravenous injection to guide the precise combined treatment time. However, due to the local delivery and controlled release of inhibitors, HPDA@MK down-regulates c-MYC/PD-L1/CD47, promotes the activation and recruitment of cytotoxic T cells, regulates the M2 macrophages polarization in tumor sites, and especially boosts the combined therapeutic efficacy. Collectively, our work presents a simple but distinctive approach for c-MYC/PD-L1/CD47-targeted immunotherapy combined with PTT that may provide a desirable and feasible strategy for the treatment of other clinical solid tumors.

Rational Design of Polymethine Dyes with NIR-II Emission and High Photothermal Conversion Efficiency for Multimodal-Imaging-Guided Photo-Immunotherapy

Phototheranostics have emerged and flourished as a promising pattern for cancer theranostics owing to their precise photoinduced diagnosis and therapeutic to meet the demands of precision medicine. The diagnosis information and therapeutic effect are directly determined by the fluorescence imaging ability and photothermal conversion efficiency (PCE) of phototheranostic agents. Hence, how to balance the competitive radiative and nonradiative processes of phototheranostic agents is the key factor to evaluate the phototheranostic effect. Herein, molecules named ICRs with high photostaibility  are rationally designed, exhibiting fluorescence emission in the second near-infrared window (NIR-II, 1000-1700 nm) and high PCE, which are related to the strong donor-acceptor (D-A) interaction and high reorganization energy Noteworthily, ICR-Qu with stronger D-A interaction and a large-sized conjugated unit encapsulated in nanoparticles exhibits high PCE (81.1%). In addition, ICR-QuNPs are used for fluorescence imaging (FLI), photoacoustic imaging (PAI), and photothermal imaging (PTI) to guide deep-tissue photonic hyperthermia, achieving precise removal and inhibition of breast cancer. Furthermore, combined with α-PD-1, ICR-QuNPs show huge potential to be a facile and efficient tool for photo-immunotherapy. More importantly, this study not only reports an "all-in-one" polymethine-based phototheranostic agent, but also sheds light on the exploration of versatile organic molecules for future practical applications.

Two-Wave Variable Nanotheranostic Agents for Dual-Mode Imaging-Guided Photo-Induced Triple-Therapy for Cancer

Photothermal therapy (PTT) is a promising strategy for cancer treatment, but its clinical application relies heavily on accurate tumor positioning and effective combination. Nanotheranostics has shown superior application in precise tumor positioning and treatment, bringing potential opportunities for developing novel PTT-based therapies. Here, a nanotheranostic agent is proposed to enhance magnetic resonance imaging (MRI)/ near-infrared fluorescence imaging (NIRFI) imaging-guided photo-induced triple-therapy for cancer. Thermosensitive liposomes co-loaded with SPIONs/IR780 and Abemaciclib (SIA-TSLs), peptide ACKFRGD, and click group 2-cyano-6-amino-benzothiazole (CABT) are co-modified on the surface of SIA-TSLs to form SIA-αTSLs. ACKFRGD can be hydrolyzed to expose the 1, 2-thiolamino groups in the presence of cathepsin B in tumors, which click cycloaddition with the cyano group on CABT, resulting in the formation of SIA-αTSLs aggregates. The aggregation of SIA-αTSLs in tumors enhances the MRI/NIRFI imaging capability and enables precise PTT. Photo-induced triple-therapy enhances precision cancer therapy. First, PTT ablates specific tumors and induces ICD via localized photothermal. Second, local tumor heating promotes the rupture of SIA-αTSLs, which release Abemaciclib to block the tumor cell cycle and inhibit Tregs proliferation. Third, injecting GM-CSF into tumor tissue leads to recruitment of dendritic cells and initiation of antitumor immunity. Collectively, these results present a promising nanotheranostic strategy for future cancer therapy.

Targeted NIR-responsive theranostic immuno-nanomedicine combined TLR7 agonist with immune checkpoint blockade for effective cancer photothermal immunotherapy

Nanomedicine with immunotherapy offers opportunities to target cancer in an effective manner; however, it remains challenging. We herein report a photothermal material loaded with immune-adjuvant combined immune checkpoint blockade for efficient cancer immunotherapy to target estrogen receptor-positive (ER⁺) breast cancer (BC). Endoxifen (END) expressly targets ER⁺ breast cancer cells. As a proof of concept of a targeting ER⁺ agent, END/NIR-responsive polyaniline (PANi)/a toll-like-receptor-7 agonist imiqumoid (R837) activating immune response co-encapsulated nanoparticles were formed as END-PANi-PVP@R837 NPs and found to be very appropriate as an NIR-responsive photothermal platform for versatile immunogenic cell death (ICD) in combination with an immune checkpoint PD-L1 blockade for development as an immunotherapy strategy. In this study, we concentrate on the therapeutic tactic of combining anti-PD-L1 with NPs, not only ablating cancer cells upon NIR irradiation but also providing strong anti-cancer immunity to destroy tumor progression after treatment. In both in vitro and in vivo experiments it was demonstrated that NPs could efficiently activate PTT to induce an immune response and immune resistance based on the PD-L1 checkpoint to ablate the tumor and inhibit tumor recurrence. We confirm the potency of the NPs, which exhibit high photothermal conversion efficacy and stability. The results demonstrate that the NP combination suppresses tumor cell growth at the tumor margin beyond effective PTT and immunotherapy.

Mechanisms of chemotherapeutic resistance and the application of targeted nanoparticles for enhanced chemotherapy in colorectal cancer

Colorectal cancer is considered one of the major malignancies that threaten the lives and health of people around the world. Patients with CRC are prone to post-operative local recurrence or metastasis, and some patients are advanced at the time of diagnosis and have no chance for complete surgical resection. These factors make chemotherapy an indispensable and important tool in treating CRC. However, the complex composition of the tumor microenvironment and the interaction of cellular and interstitial components constitute a tumor tissue with high cell density, dense extracellular matrix, and high osmotic pressure, inevitably preventing chemotherapeutic drugs from entering and acting on tumor cells. As a result, a novel drug carrier system with targeted nanoparticles has been applied to tumor therapy. It can change the physicochemical properties of drugs, facilitate the crossing of drug molecules through physiological and pathological tissue barriers, and increase the local concentration of nanomedicines at lesion sites. In addition to improving drug efficacy, targeted nanoparticles also reduce side effects, enabling safer and more effective disease diagnosis and treatment and improving bioavailability. In this review, we discuss the mechanisms by which infiltrating cells and other stromal components of the tumor microenvironment comprise barriers to chemotherapy in colorectal cancer. The research and application of targeted nanoparticles in CRC treatment are also classified.

Synthesis of strong electron donating-accepting type organic fluorophore and its polypeptide nanoparticles for NIR-II phototheranostics

A novel NIR-II small-molecule D-A type organic fluorophore conjugation of triphenylamine, thiophene, and benzo[c,d] indol groups (TPA-Et) with strong electron-donating and accepting groups has been synthesized. The dye shows a significant Stokes shift for efficient fluorescence in the NIR-II region and high photothermal performance. The TPA-Et was then encapsulated by an amphiphilic copolymer P(OEGMA)₂₀-P(Asp)₁₄, and micelles (P@TP) has been prepared with outstanding NIR-II imaging performance, excellent photothermal conversion efficiency (52.5%) under 808 nm laser irradiation, and good photostability. Fluorescence imaging experiments have consistently shown that P@TP can image tiny blood vessels in mice, enrich effectively in the tumor region, and maintain a relatively stable NIR-II fluorescence signal in the tumor area for a long time up to 60 h. In vivo photothermal therapy has a highly significant anticancer effect without tumor recurrence, demonstrating the apparent advantages of P@TP as a NIR nanotheranostic platform in NIR-II imaging-guided photothermal therapy.

Minimally invasive nanomedicine: nanotechnology in photo-/ultrasound-/radiation-/magnetism-mediated therapy and imaging

Traditional treatments such as chemotherapy and surgery usually cause severe side effects and excruciating pain. The emergence of nanomedicines and minimally invasive therapies (MITs) has brought hope to patients with malignant diseases. Especially, minimally invasive nanomedicines (MINs), which combine the advantages of nanomedicines and MITs, can effectively target pathological cells/tissues/organs to improve the bioavailability of drugs, minimize side effects and achieve painless treatment with a small incision or no incision, thereby acquiring good therapeutic effects. In this review, we provide a comprehensive review of the research status and challenges of MINs, which generally refers to the medical applications of nanotechnology in photo-/ultrasound-/radiation-/magnetism-mediated therapy and imaging. Additionally, we also discuss their combined application in various fields including cancers, cardiovascular diseases, tissue engineering, neuro-functional diseases, and infectious diseases. The prospects, and potential bench-to-bedside translation of MINs are also presented in this review. We expect that this review can inspire the broad interest for a wide range of readers working in the fields of interdisciplinary subjects including (but not limited to) chemistry, nanomedicine, bioengineering, nanotechnology, materials science, pharmacology, and biomedicine.

Acid-Sensitive Nanoparticles Based on Molybdenum Disulfide for Photothermal-Chemo Therapy

The combination of multiple treatments has recently been investigated for tumor treatment. In this study, molybdenum disulfide (MoS₂) with excellent photothermal conversion performance was used as the core, and manganese dioxide (MnO₂), which responds to the tumor microenvironment, was loaded on its surface by liquid deposition to form a mesoporous core-shell structure. Then, the chemotherapeutic drug Adriamycin (DOX) was loaded into the hole. To further enhance its water solubility and stability, the surface of MnO₂ was modified with mPEG-NH₂ to prepare the combined antitumor nanocomposite MoS₂@DOX/MnO₂-PEG (MDMP). The results showed that MDMP had a diameter of about 236 nm, its photothermal conversion efficiency was 33.7%, and the loading and release rates of DOX were 13 and 65%, respectively. During in vivo and in vitro studies, MDMP showed excellent antitumor activity. Under the combined treatment, the tumor cell viability rate was only 11.8%. This nanocomposite exhibits considerable potential for chemo-photothermal combined antitumor therapy.

Multimodal Imaging-Guided Photothermal Immunotherapy Based on a Versatile NIR-II Aggregation-Induced Emission Luminogen

Synergistic photothermal immunotherapy has captured great attention owing to the mutually strengthening therapeutic outcomes towards both original tumors and abscopal tumors. Herein, a versatile theranostic agent displaying aggregation-induced emission, namely TPA-BT-DPTQ, was designed and prepared based on benzo[c]thiophene unit as a building block; it can be used for simultaneous fluorescence imaging (FLI) in the second near-infrared (NIR-II) window, photoacoustic imaging (PAI), photothermal imaging (PTI), and thermal eradication of tumors. Further experiments validate that photothermal therapy (PTT) mediated by TPA-BT-DPTQ nanoparticles not only destroys the primary tumor but also enhances immunogenicity for further suppressing the growth of tumors at distant sites. Furthermore, PTT combining a programmed death-ligand 1 (PD-L1) antibody prevents the metastasis and recurrence of cancer by potentiating the effect of immunotherapy.

Cancer immunogenic cell death via photo-pyroptosis with light-sensitive Indoleamine 2,3-dioxygenase inhibitor conjugate

Immune checkpoint blockade (ICB) therapy currently considered as to be effective way to cure cancer in clinic. However, the insufficient tumor immunogenicity and the immunosuppressive tumor microenvironment always result in diminished efficacy of immunotherapy. Herein, we report the synthesis of an organic photo-immune activator NBS-1MT, the combination of photosensitizer and Indoleamine 2,3-dioxygenase (IDO) inhibitor effectively stimulates lysosomes oxidative stress the releases inflammatory cytokines. This process triggers pyroptosis for the considerable immunogenic cell death (ICD) while reversing suppressive tumor microenvironment. The photo-immune drug shows outstanding potential to activate caspase-1and then remove gasdermin-D (GSDMD), which could stimulate pyroptosis and also inhibit the tumor growth successfully in both primary and distant tumor. Furthermore, pyroptosis activated by photodynamic therapy (PDT) promotes the immune related factors release, and enhance the intratumoral infiltration of cytotoxic T lymphocytes (CTLs) with the induction of ICD of tumor cells and the cascaded synergize with IDO inhibitor, so the general antitumor immune response could be strengthened effectively. Our research confirms that the use of NBS-1MT is a promising strategy to boost the immune response and eventually to inhibit tumor growth.

Vanadyl nanocomplexes enhance photothermia-induced cancer immunotherapy to inhibit tumor metastasis and recurrence

Conventional photothermal therapy (PTT) is insufficient to induce a strong and potent anti-tumor immune response. Herein, we present a vanadyl nanocomplex, which simultaneously serves as a photothermal agent (PTA) and an immunogenic cell death (ICD) inducer to enhance the anti-tumor immunity of PTT. The vanadyl nanocomplex (STVN) is constructed via facile one-step coordination assembly under ambient conditions. STVN not only has a strong and stable photothermal effect under near-infrared (NIR) irradiation, but also can cause severe endoplasmic reticulum (ER) stress by itself, leading to ICD and activating the systemic immune responses. In the absence of any adjuvants, NIR-irradiated STVN almost completely ablates primary tumors and simultaneously inhibits distant tumors in mice bearing bilateral melanoma. Meanwhile, the intratumorally injected STVN combined with NIR effectively suppressed melanoma lung metastasis as well as tumor recurrence, displaying that local STVN-mediated PTT could trigger a systemic anti-tumor immunity. Therefore, STVN, as a novel immunogenicity-enhanced PTA, affords a "one stone two birds" strategy for improved photothermia-induced cancer immunotherapy.