Organic molecule-based photothermal agents: an expanding photothermal therapy universe

Nucleic Acid-Modified Nanoparticles for Cancer Therapeutic Applications

Nanomaterials including metal or metal oxide nanoparticles, carbonous nanomaterial (e.g., carbon dots) or metal-organic framework nanoparticles provide porous, catalytically active surfaces and functional interfaces for binding of ions or molecular agents. By the conjugation of nucleic acids to the nanoparticles, hybrid nanostructures revealing emerging multimodal catalytic/photocatalytic activities, high loading capacities, and effective targeted cell permeation efficacies are formed. The review article exemplifies the application of nucleic acid-modified nanoparticles conjugates for therapeutic treatment of cancer cells. Stimuli-responsive reconfiguration of nucleic acid strands and the specific recognition and catalytic function of oligonucleotides associated with porous, catalytic, and photocatalytic nanoparticles yield hybrid composites demonstrating cooperative synergistic properties for medical applications. The targeted chemodynamic, photodynamic, photothermal and chemotherapeutic treatment of cancer cells by the oligonucleotide/nanoparticle conjugates is addressed. In addition, the application of oligonucleotide/nanoparticle conjugates for gene therapy treatment of cancer cells is discussed.

Fluorescence and photothermal dual-modal image guided integrated diagnosis and treatment

The early diagnosis and real-time monitoring of cancer are great significance for the establishment of integrated diagnosis and treatment systems. In this study, organic molecules as an all-in-one phototheranostic named FL-DPP2 nanoparticles was developed for monitoring the location and size of tumour and for achieving photo and gene synergistic therapy. The photothermal conversion efficiency (η) of FL-DPP2 nanoparticles reached 29.4 % and the quantum yield of 1O2 production was 38 %. In addition, it can deliver the p53 gene into nucleus rapidly under laser irradiation, which induced synergistic cancer cells apoptosis with effective tumor growth inhibition. This work provided an innovative strategy to design and constructed all-in-one nanoplatforms for clinical phototheranostics to realize dual-modal image guided integrated diagnosis and treatment.

Hesperidin Derivatives Contained Hydrogel Dressing for Photothermal Treatment of Melanoma and Postoperative Tissue Regeneration

Melanoma is a severe malignant skin tumor. It is crucial to effectively eliminate melanoma and promote rapid and healthy regeneration of postoperative tissue defects. Herein, hesperidin derivatives (HD) have been developed as the bioactive components of hydrogels that are capable of ablating melanoma via photothermal therapy (PTT) and promoting tissue regeneration. HD have been prepared by heating hesperidin alkaline solution followed by dialysis and lyophilization, and GelMA hydrogels encapsulating HD kill cancer cells and bacteria under near-infrared (NIR) irradiation. The in vitro test and in vivo transcriptomic analysis confirmed that the HD containing GelMA hydrogels induce the immunogenic cell death (ICD) effect of tumor cells by significantly upregulating chemokine-related, cytokine-related, and apoptosis-related genes, thereby enhancing therapeutic efficacy. In a mouse model of infected skin wounds, the HD containing hydrogels under 808 nm light irradiation effectively promoted wound repair. This was achieved through accelerated wound closure and enhanced skin regeneration, mediated by increased angiogenesis and collagen deposition. In conclusion, the HD containing hydrogels provide a new strategy for the clinical treatment of melanoma and postoperative tissue defect repair following operative resection of cancer.

Nonconjugated Structural Distortion Promoting the Formation of NIR Triplet States in Phenothiazine Dyes for Cancer Photoimmunotherapy

Near-infrared (NIR) triplet-state dyes are pivotal for advanced biomedical and material science applications. Although numerous strategies have been proposed to enhance the photosensitization efficiency of dyes, significant challenges remain. Herein, we propose a novel strategy leveraging nonconjugated structural distortion to enhance triplet-state formation. This strategy, achieved by introducing steric groups at the edges of the phenothiazine (PTZ) dye framework, notably enhances intersystem crossing (ISC) and prolongs triplet-state lifetime. Based on this strategy, HNBS and HNBSe are synthesized, which exhibit exceptional triplet-state quantum yields (47.2% for HNBS and 87.7% for HNBSe) and prolonged triplet-excited-state lifetimes (21.1 µs for HNBS and 6.3 µs for HNBSe). These values substantially exceed those of conventional dyes, such as NBS (negligible and NBSe (3.2 µs). Under ultralow-light doses (0.45 J cm- 2 in vitro, and 6 J cm- 2 in vivo), these photosensitizers demonstrate robust tumor cell inhibition, highlighting their exceptional photosensitizing ability. Mechanistically, HNBS possesses lysosomal-targeting ability, and upon light irradiation, it induces lysosomal damage, triggering pyroptosis and immunogenic cell death. These processes promote dendritic cell maturation and T-cell differentiation, augmenting the immune response and enabling effective photoimmunotherapy.

Recent advances in anti-tumor mechanisms and biological applications of vanadium compounds

Vanadium, a transition metal, has emerged as a promising element in the development of therapeutic drugs. While not an essential element for life, vanadium compounds have demonstrated significant potential as anticancer agents. Current evidence suggests that these compounds exert their anti-tumor effects through multiple mechanisms, including DNA damage, cell cycle regulation, induction of apoptosis and autophagy, inhibition of metastasis and invasion, and disruption of mitochondrial function. Furthermore, vanadium compounds have shown efficacy against a wide range of cancers, such as melanoma, breast, colorectal, pancreatic, liver, and central nervous system tumors, as well as oral squamous cell carcinoma. This review aims to comprehensively examine the anti-tumor properties and underlying mechanisms of various vanadium compounds while also providing an overview of their current biological applications.

Small Molecule-Mediated Photothermal Therapy Induces Apoptosis in Cancer Cells

Cancer remains as one of the most life-threatening diseases in the whole world. Most of the therapeutic strategies to eradicate cancer are highly invasive, leading to severe injury and trauma to the patients. In recent times, phototherapy has emerged as one of the noninvasive therapeutic strategies for cancer treatment. However, development of novel small-molecule photothermal agents remains a major challenge. To address this, herein, a small molecule library having aromatic substituted-3-methoxy-pyrrole and 2-(3-cyano-4,5,5-trimethylfuran-2(5 H)-ylidene) malononitrile in a concise synthetic strategy is designed and synthesized. One of the library members (7H) self-assembles into spherical-like nanoparticles having <100 nm size in water and is found to exhibit remarkable increase in temperature under 740 nm near-infrared (NIR) light. Interestingly, compound 7H homes into the lysosomal compartments and the lipid droplets in the HCT-116 colon cancer cells within 3 h and induces photothermal effect followed by generation of reactive oxygen species while irradiating under 740 nm NIR light for 10 min. Moreover, 7H triggers programmed cell death (apoptosis) to induce remarkable HCT-116 cell killing. This small molecule-mediated photothermal effect shows potential to be an interesting tool for the next-generation noninvasive cancer phototherapy.

A conjugated molecule based on tetra-fused thienoisoindigo ribbon for NIR-II photothermal cancer therapy

Water-soluble nanoparticles (NPs) based on the well-defined 4ThIID molecules, namely 4ThIID NPs, were prepared. Benefiting from the strong NIR-II absorption and high photothermal conversion properties of 4ThIID, the ε1064 × PTCE1064 value of 4ThIID NPs reaches 9.18 × 104, which is the highest value among the reported NIR-II photothermal small molecules. In vivo experiments show that 4ThIID NPs can effectively inhibit the growth of tumors in mouse models under the irradiation of a 1064 nm laser.

Lignin-Based Photothermal Materials: Bridging Sustainability and High-Efficiency Energy Conversion

Photothermal materials can effectively absorb light and convert it into heat, providing sustainable solutions to mitigate environmental pollution and energy shortages. Compared to traditional photothermal materials, lignin has garnered significant attention due to its wide availability, low cost, biocompatibility, renewability, and sustainability. Consequently, lignin-based materials are considered ideal candidates for the development of eco-friendly photothermal systems, aligning well with the increasing demand for sustainable energy solutions. This review discusses the potential of lignin-based photothermal materials, highlighting their unique molecular structure and the photothermal properties imparted by their aromatic rings, which facilitate effective energy conversion through non-radiative vibrational relaxation. Discussed the latest advances in the applications of lignin photothermal materials in photothermal drive, solar desalination, and biomedicine. Despite the significant potential of lignin, challenges such as structural variability, long-term stability, and scalability remain critical. This paper integrates recent progress and proposes strategies to optimize the photothermal performance of lignin-based materials, while emphasizing important directions for sustainable development, thereby providing a roadmap to fully realize the potential of lignin in next-generation green technologies.

Dual-drug loaded hyaluronic acid conjugates coated polydopamine nanodrugs for synergistic chemo-photothermal therapy in triple negative breast cancer

Although combination of chemotherapy and photothermal therapy (PTT) holds significant promise for treating triple-negative breast cancer, the existing delivery systems for achieving synergistic antitumor activity remains unsatisfactory. Herein, we developed of dual-drug loaded hyaluronic acid (HA) nanodrugs, which exhibited pH, glutathione (GSH), and thermal triple-responsiveness and CD44-targeting capabilities for chemo-PTT synergistic therapy in breast cancer. Gemcitabine (GCB) and metformin (MET) were conjugated to HA via amide and disulfide bonds to form dual-drug loaded prodrugs (HSGM), which were then coated onto the surface of polydopamine nanoparticles (PDA NPs) to self-assemble into HSGM/PDA NPs. These NPs selectively accumulated at the tumor site through HA receptors and released GCB and MET in response to low pH and high GSH concentrations. The NPs demonstrated excellent photothermal performance, with heat generated from near-infrared (NIR)-laser irradiation accelerating drug release within tumor. Additionally, MET inhibited the production of heat shock protein 70 (HSP 70), mitigating thermotolerance induced by PTT, thereby enhancing the PTT effect. The combination of chemotherapy and PTT synergistically improved anti-tumor efficacy (tumor inhibition ratio: 99.11 %) while showing negligible systemic toxicity, effectively preventing tumor metastasis and recurrence. This integrated approach offers valuable insights for the clinical treatment of breast cancer and other malignant tumors.

Biomimetic modification of macrophage membrane-coated prussian blue nanoparticles loaded with SN-38 to treat colorectal cancer by photothermal-chemotherapy

SN-38 is the active metabolite of irinotecan and acts as an effective topoisomerase I inhibitor with therapeutic effects on many malignant tumors, including some drug-resistant cancers. However, the poor solubility, low bioavailability, and severe dose-dependent toxicity limits the clinical application of SN-38. Currently, emerging macrophage membrane-coated nanoparticles provide an efficient biomimetic approach to develop novel SN-38 formulations for the reduction of its side effects. Photothermal therapy (PTT) is a promising methods in tumor treatment to thermally ablate tumors using various materials such Prussian blue nanoparticles (NPs) and can combined with chemotherapy to synergistically work. There is no report that combined SN38 and photothermal therapy for the treatment of colorectal cancer (CRC). SN38-PB@CM NPs were constructed by loading SN-38 into macrophage cell membrane-coated hollow mesoporous Prussian blue (PB) NPs. The morphology, size and zeta potential were evaluated by transmission microscopy and dynamic light scatter (DLS). Coomassie bright blue staining was performed to assess total protein profile. The photothermal properties of it were also investigated via near-infrared imaging. CCK8 and calcein-AM/PI staining were used to evaluate cell viability. Flow cytometry was performed to assess cell apoptosis. The fluorescent microscopy was used to observe cellular uptake of SN38-PB@CM NPs to assess its internalization in vitro. The biodistribution, tumor-targeting efficacy, antitumor efficacy and safety of SN38-PB@CM NPs in vivo were assessed in CT26 tumor-bearing mice via In Vivo Imaging System. SN38-PB@CM NPs were successfully constructed and exhibited a uniform size distribution (140.5 ± 4.3 nm) and an excellent drug-loading capacity (5.61 ± 0.64%). SN38-PB@CM NPs showed stable release properties within 72 h. It can also enhance the selective intracellular delivery of SN38 in vitro and showed good near-infrared (NIR) photothermal properties. And the NPs showed excellent tumor targeting, effective photothermal therapy, improved biosafety and antitumor efficacy on CT26-bearing mice. Multifunctional SN38-PB@CM NPs could achieve improved biosafety, great tumor-targeting, high-efficiency PTT and excellent antitumor efficacy, which provided a promising and attractive combination therapy for the treatment of CRC.

Enhancing the photothermal properties of indocyanine green in melanoma spheroids via encapsulation in Span 80-containing lipid nanocapsules

Indocyanine green (ICG), a well-known photosensitiser, has shown potential in photothermal therapy (PTT) for cancer treatment, but its effectiveness is limited by poor skin penetration and rapid clearance. To address this, lipid nanocapsules (LNCs) were used as nanocarriers to enhance ICG's cellular uptake and photothermal (PT) performance in melanoma cells. Utilising our recently developed Span 80-modified LNCs (LNC100-S8) with high biocompatibility and enhanced cellular uptake in B16F10 melanoma cells, ICG was loaded into LNC100-S8 using the phase inversion temperature method. The results showed that ICG encapsulation at 4.5 mg/mL maintained small LNC sizes (95-105 nm). Moreover, the heating capacity of ICG in LNCs was approximately 1.5 times higher than free ICG, achieving temperature increases over 10 °C post-irradiation. In cell cancer monolayers, LNC100-S8 enhanced ICG uptake by 1.5 times compared to free ICG and reduced cell viability to 50 % following 808 nm laser irradiation. More promisingly, ICG-LNC100-S8 combined with laser irradiation significantly reduced three-dimensional B16F10 spheroids size up to 11 days post-treatment compared to free ICG. Overall, our findings validate LNC100-S8, as promising nanocarriers for enhancing ICG-based PTT, supporting their potential applications in vivo to treat melanoma and other skin cancers.

Hypoxia-Targeted-Therapy: Mussel-inspired hollow polydopamine nanocarrier containing MoS2 nanozyme and tirapazamine with anti-angiogenesis property for synergistic tumor therapy

Photothermal therapy (PTT) using thermal and tumor microenvironment-responsive reagents is promising for cancer treatment. This study demonstrates an effective PTT nanodrug consisting of hollow-structured, thermally sensitive polydopamine nanobowls (HPDA NB), molybdenum sulfide (MoS2) nanozyme, and tirapazamine (TPZ; a hypoxia-responsive drug), with a structure of HPDA@TPZ/MoS NBs, which is hereafter denoted as HPTZMoS NBs. With the Fenton-like activity, the HPTZMoS NBs in the presence of H2O2 catalyze the formation of hydroxyl radicals, providing chemodynamic therapy (CDT) effect and deactivating glutathione. Under acidic conditions, HPTZMoS NBs facilitate the release of sulfide ions (S2-) and TPZ, providing a combination of chemotherapy (CT) and hydrogen sulfide (H2S) gas therapy (GT). Under an 808-nm NIR laser irradiation, the HPTZMoS NBs efficiently convert photo energy to thermal energy, providing PTT and improved CDT, CT, and GT effects. Upon treatment with an NIR laser and H2O2, a synergistic effect leads to substantial tumor cell eradication. Additionally, HPTZMoS NBs disrupt vascular endothelial growth factor (VEGF-A165)-induced cell migration in human umbilical vein endothelial cells through its strong interaction with VEGF-A165. In vivo studies in 4T1-tumor-bearing mice confirm that HPTZMoS NBs induces significant tumor destruction through a combination of PTT, hyperthermia-induced CDT, GT, and CT pathways. This study presents a multifaceted, highly selective nanotherapy platform with potent anti-angiogenesis properties, holding significant promise for future clinical applications.

Carbohydrate polymer-functionalized metal nanoparticles in cancer therapy: A review

Metal nanoparticles have been emerged as promising candidates in cancer therapy because of their large surface area, optical properties and ROS generation. Therefore, these nanoparticles are able to mediate cell death through hyperthermia, photothermal therapy and ROS-triggered apoptosis. The various metal nanoparticles including gold, silver and iron oxide nanostructures have been exploited for the theranostic application. Moreover, precision oncology and off-targeting features can be improved by metal nanoparticles. The modification of metal nanoparticles with carbohydrate polymers including chitosan, hyaluronic acid, cellulose, agarose, starch and pectin, among others can significantly improve their anti-cancer activities. Carbohydrate polymers have been idea for the purpose of drug delivery due to their biocompatibility, biodegradability and increasing nanoparticle stability. In addition, carbohydrate polymers are able to improve drug delivery, cellular uptake and sustained release of cargo. Such nanoparticles are capable of responding to the specific stimuli in the tumor microenvironment including pH and light. Furthermore, the carbohydrate polymer-modified metal nanoparticles can be utilized for the combination of chemotherapy, phototherapy and immunotherapy. Since the biocompatibility and long-term safety are critical factors for the clinical translation of nanoparticles, the modification of metal nanoparticles with carbohydrate polymers can improve this way to the application in clinic.

GSH-Triggered Nitric Oxide Release from Polyurethane Nanocarriers for Gas-Photothermal Synergistic Therapy of Bacterial-Infected Wounds

Wound bacterial infections pose a significant challenge to global public health. Nitric oxide (NO), an endogenous gaseous molecule, shows great potential in antibacterial therapy. However, efficient NO delivery remains a critical challenge. Photothermal therapy (PTT) offers a noninvasive and highly localized treatment for bacterial infections. Leveraging the advantages of both approaches, this study developed a polymer-based nanocarrier to achieve synergistic NO delivery and PTT. For the first time, an amphiphilic polyurethane PEG-PNU-PEG containing dinitrate NO donors were synthesized, which further self-assembled into polymeric nanomicelles loaded with a NIR emitting conjugated polymer. In the bacterial microenvironment, elevated glutathione (GSH) triggered NO release. Simultaneously, the conjugated polymer enabled effective photothermal therapy, further promoting NO release for gas therapy. Experimental results demonstrated that the synergistic NO and PTT treatment effectively eradicated bacteria, eliminating 69.93% ± 2.79% of S. aureus biofilm, a > 4.5-fold improvement compared to NO treatment alone (14.8% ± 2.92%). The in vitro antibacterial assay showed an inhibition rate exceeding 99.0%, while in vivo studies on infected skin wounds revealed a bacterial clearance rate of 95.0% ± 1.95%. Furthermore, this system suppressed inflammatory cytokines, promoted collagen deposition, and accelerated skin regeneration, providing an effective strategy for broad-spectrum antibacterial therapy and wound healing.

High-Efficiency ICG Molecular Vibration Therapy for Bradyarrhythmia Using Cardiomyocyte-Based Biosensing

Bradyarrhythmia is a major cause of cardiovascular disease morbidity and mortality. Currently, medication and/or surgery are the conventional clinical therapeutic strategies for bradyarrhythmia, whereas drug side effects, invasive surgery, or potential complications limit their extensive application. Therefore, the development of alternative therapies for bradyarrhythmia is urgently needed. Herein, we propose a universal and efficient drug-mimicking strategy to treat bradyarrhythmia, which relies on the photothermal properties of near-infrared-triggered indocyanine green (ICG). An in situ integrated cell-based biosensing-regulating platform was developed to assess treatment efficacy by dynamically analyzing the cardiomyocyte electrophysiology activities. These findings indicate that the thermal vibration of ICG can efficiently enhance the electrophysiology of cardiomyocytes with bradyarrhythmia and maintain a rhythmic state for a long time, which is superior to that of Au nanorod plasmonic localized heating. Moreover, qualitative investigations confirmed that thermal stimulation is a pivotal factor in enhancing cardiomyocyte electrophysiological activity during photothermal treatment. This study provides a noninvasive drug-mimicking treatment strategy for bradyarrhythmia and establishes a reliable cell-based biosensing-regulating platform for electrophysiological assessment and drug screening, contributing to the further development of bradyarrhythmia therapies.

Intratumoral self-assembly of renal-clearable gold nanoparticles as precise photothermal nanomedicine for liver tumor therapy

Noninvasive photothermal therapy (PTT) for cancer with photothermal agents (PTAs) has recently achieved success in both preclinical and clinical trials. However, traditional PTAs tend to nonspecifically accumulate in normal liver tissue, hampering their use in PTT of liver tumors. By taking advantage of extremely low liver accumulation from ultrasmall renal-clearable gold nanoparticles (AuNPs), we report a biosafe therapeutic PTT strategy to treat liver tumors precisely through the intratumoral self-assembly of renal-clearable AuNPs at the tumor site via host-guest interactions. After active tumor targeting from the host AuNPs functionalized with both cyclo (Arg-Gly-Asp-d-Phe-Cys) and cyclodextrin, the guest AuNPs functionalized with both pH-responsive doxorubicin and adamantane are designed to precisely trigger intratumoral self-assembly, enhancing both PTT and chemotherapy toward the liver tumor microenvironment. This smart design principle generates a precise therapeutic action toward liver tumors without causing any noticeable heating effect or damage to the surrounding normal liver tissue.

Biomimetic Copper-Based Nanoplatform for Enhanced Tumor Targeting and Effective Melanoma Therapy

Designing advanced biomimetic nanoplatforms that combine photothermal therapy (PTT) and immune activation represents a modern approach to addressing the challenges of cancer therapy. This study presents a nanobiomimetic hollow copper-sulfide (HCuS) platform for precise homotypic tumor targeting and melanoma treatment. The HCuS@OVA@CM (COC) nanoplatform-encapsulated ovalbumin (OVA) antigen protein within HCuS nanoparticles and was coated with melanoma cell membranes (B16F10). Importantly, this design facilitates specific tumor accumulation and achieves 16.0% photothermal conversion efficiency under 1064 nm NIR-II irradiation, which is a key factor for therapeutic success. In vitro studies have demonstrated that this nanoplatform induces immunogenic cell death (ICD), enhances antigen presentation, and stimulates dendritic cell (DCs) maturation. In vivo experiments confirmed that COC-mediated NIR-II photothermal treatment significantly suppressed tumor growth without notable body weight loss. This biomimetic nanoplatform approach offers a targeted, enhanced, and effective immune response for tumor photothermal immunotherapy, making it a promising candidate for advanced melanoma treatment and anticancer therapy.

Reduced graphene oxide quantum dots/manganese dioxide/glucose oxidase nanoparticles for cascade catalytic cancer treatment in multimodal starvation therapy-augmented chemodynamic/photothermal therapy

Combination cancer therapy can boost the overall treatment efficacy using functional nanomaterials that specifically target cancer cells. Furthermore, the treatment outcome can be improved by focusing on specific characteristics in the tumor microenvironment (TME). In this study, tumor-targeting multifunctional nanoparticles were constructed from reduced graphene oxide quantum dots (rGOQD), manganese dioxide (MnO2), glucose oxidase (GOx), and cell-penetrating peptide (CPP). The rGOQD/MnO2/GOx/CPP nanoparticles can treat tumors by strengthening chemodynamic/photothermal therapy (CDT/PTT) with starvation therapy (ST). The MnO2 reacts with high concentrations of endogenous H2O2 in an acidic TME to produce reactive oxygen species (ROSs) from Mn2+. The highly cytotoxic hydroxyl radical (•OH) kills cancer cells and initiates CDT. The MnO2 can also consume the •OH scavenger glutathione (GSH) in cancer cells and eliminate their antioxidant defense. The GOx oxidizes glucose to cause cancer cell glucose starvation for ST, which produces H2O2 to boost the efficacy of CDT. By consuming glucose, ST mediated by GOx leads to reduced ATP production in the glycolysis pathway. This downregulates the expression of ATP-dependent heat shock proteins that provide cancer cell thermal resistance when the photothermal agent rGOQD is irradiated with near-infrared (NIR) light for PTT. Therefore, we prepare different rGOQD-based nanoparticles and characterize their physicochemical and biological properties. The nanoparticles were studied in vitro against U87 glioblastoma cells for targeted cancer therapy. Using nude mice bearing subcutaneous U87 tumors, the in vivo study indicates rGOQD/MnO2/GOx/CPP plus NIR irradiation can substantially inhibit the tumor growth rate without causing adverse effects from CPP-mediated trimodal ST/CDT/PTT.

NIR-Triggered siRNA Release and Lysosomal Escape for Synergistic Photothermal Tumor Therapy

Background

Resistance to traditional treatments has spurred research into innovative therapeutic approaches for tumors. Among these innovative treatments, photothermal therapy (PTT) has gained increasing attention for its use of photothermal agents (PTAs) to convert light into heat for localized tumor ablation. However, PTT faces limitations due to heat shock protein 70 (HSP70)-mediated resistance in tumor cells. Combining PTT via indocyanine green (ICG) with siRNA HSP70 could reduce the thermal resistance of the tumor, thereby enhancing treatment efficacy. Albumin-based nanoparticles (NPs) can effectively deliver ICG and siRNA into tumor cells. When exposed to near-infrared (NIR) light, these nanoparticles trigger lysosomal escape and release, further enhancing gene silencing activity.

Methods

This study aimed to develop a biocompatible delivery system, HSA@ICG/siRNA NPs, for photothermal-enhanced tumor therapy. The nanoparticles were characterized for size, charge, surface functionalization, and photoconversion properties. In vitro antitumor efficacy was evaluated using MTT assay, calcein AM/PI staining, RT-PCR, and Western blot in 4T1 tumor cells. In vivo, we assessed photothermal effects, biodistribution, tumor inhibition, and biosafety following irradiation.

Results

Characterization confirmed the successful synthesis of uniform, stable HSA@ICG/siRNA NPs with effective photothermal conversion properties. Cellular uptake studies revealed high siRNA internalization, with laser-induced lysosomal escape enhancing cytoplasmic delivery. In vitro, gene silencing reduced mRNA and protein levels by 82.8% and 65%, respectively. In vivo, local tumor temperature increased to 42°C within 3 minutes, indicating a mild but effective photothermal effect. Tumor inhibition rates were 50.00% ± 9.16% for HSA@ICG and 71.26% ± 7.92% for HSA@ICG/siRNA, demonstrating enhanced tumor suppression. The treatment achieved sustained tumor targeting with minimal off-target toxicity.

Conclusion

As a dual-function photothermal therapy agent, HSA@ICG/siRNA NPs combine targeted gene silencing with photothermal effects, demonstrating significant therapeutic promise. This integrated approach addresses tumor resistance, offering a potential advancement in cancer treatment strategies.

Dual-Regulated Biomimetic Nanocomposites For Promoted Tumor Photodynamic Immunotherapy

Effective tumor immunotherapy is hindered by an immunosuppressive tumor microenvironment (TME), especially in triple-negative breast cancer. Though phototherapy could induce immunogenic cell death (ICD) to increase antitumor immunity, the simultaneous upregulation of indoleamine 2,3-dioxygenase (IDO) induces the negative immunomodulatory effect termed as the "immune-metabolism" loop to compromise immunotherapeutic efficacy. Herein, we developed IMMGP consisting of biomimetic IND-Mn@PM (IDP) and ICG-MnO2@PM (IMP), which combines the phototherapy-induced ICD and metabolic reprogramming to solve the dilemma. During the light-on phase, IMP effectively kills cancer cells with potent photodynamic ROS generation with the assistance of MnO2-produced oxygen and induces ICD to reverse the immunosuppressive TME. In the light-off phase, Mn2+ (from IDP and MnO2-based redox reaction) elicits a Fenton-like reaction to relay ROS generation, which is further orchestrated with continuous exhaustion of intratumoral GSH by the conversion of Mn3+ to Mn2+, and promotes dendritic cell maturation. Moreover, the released indoximod (IND) downregulated IDO to inhibit kynurenine metabolism, which reinvigorates T cell-mediated antitumor immunity. Collectively, IMMGP amplifies the immune response by breaking the "immune-metabolism" loop and sustaining the "immunologically hot" state after phototherapy, thus leading to nearly complete tumor inhibition (94.25%). Thus, IMMGP-mediated dual-phase photodynamic immunotherapy offers a novel approach in cancer nanomedicine.

Beneficial Probiotics with New Cancer Therapies for Improved Treatment of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a malignant form of primary liver cancer. Intricate networks linked to the host immune system may be associated with the pathogenesis of HCC. A huge amount of interdisciplinary medical information for the treatment of HCC has been accumulated over recent years. For example, advances in new immunotherapy have improved the results of treatment for HCC. This approach can be advantageously combined with standard conventional treatments such as surgical resection to improve the therapeutic effect. However, several toxic effects of treatments may pose a significant threat to human health. Now, a shift in mindset is important for achieving superior cancer therapy, where probiotic therapy may be considered, at least within the bounds of safety. The interplay between the gut microbiota and immune system could affect the efficacy of several anticancer treatments, including of immune checkpoint therapy via the alteration of Th17 cell function against various malignant tumors. Here, some recent anticancer techniques are discussed, whereby the growth of HCC may be effectively and safely repressed by probiotic therapy.

Self-Assembly of H2S-Generating Photosensitizer for Gas-Assisted Synergistic Photothermal Therapy

Photothermal therapy (PTT) is emerging as a promising cancer treatment, but uneven heat distribution increases side effects and reduces treatment precision, where high-temperature zones risk inducing undesired inflammation, while low-temperature regions are insufficient due to upregulation of heat shock proteins (HSPs). Herein, a gas-assisted PTT strategy is designed to link near-infrared heptamethine cyanine (Cy7) with self-immolative phenyl thiocarbonate (PTC), a hydrogen sulfide (H2S) donor through a disulfide bond, creating a small-molecule photosensitizer (Cy7-SS-PTC) that can self-assemble into nanoparticles (NPs) without stabilizers. Upon internalized by cancer cells, Cy7-SS-PTC NPs respond to elevated glutathione levels, and simultaneously release Cy7 and H2S via a cascade reaction. The released Cy7 reassembles into nanoaggregates, generating hyperthermia under 808 nm light irradiation, and then binds to albumin, producing strong near-infrared fluorescence to track tumors for precise treatment. The released H2S not only disrupts the mitochondrial respiratory chain, blocks ATP production, and suppresses HSP70 overexpression to amplify the efficacy of low-temperature PTT regions but also curbs proinflammatory cytokines in high-temperature PTT zones, delivering powerful tumor ablation with minimal inflammation. This small-molecule-based "H2S-assisted PTT" strategy optimizes the current PTT and validates its potential clinical application.

"Antenna Effect"-Enhanced AuNPs@rGO Photothermal Coating Promotes 3D Printing of Osteogenic Active Scaffolds to Repair Bone Defects after Malignant Tumor Surgery

Malignant bone tumor defects are difficult to treat because of the simultaneous need for tumor treatment and bone-repair promotion. This study presents a bioactive composite scaffold (T-rGO@Au) for personalized bone defect repair and bone tumor treatment. The T-rGO@Au scaffold has a porous structure, and its mechanical properties are close to those of human cancellous bone. The T-rGO@Au scaffold can induce upregulation of osteopontin (OPN), RUNX-2, and osteocalcin (OCN) gene expression. In vivo experiments showed that the bone volume/total volume (BV/TV) ratio with the T-rGO@Au scaffold was the highest. The new bone was tightly integrated with the implant, demonstrating effective osseointegration. The T-rGO@Au scaffold locally generated high temperatures and reactive oxygen species under near-infrared excitation, and AuNPs enhanced the photothermal performance of rGO through the "antenna effect." Furthermore, in vitro experiments showed that the tumor cell nuclei were destroyed, late-stage apoptotic cells increased, and cell morphology was severely damaged. Additionally, RNA-seq revealed that tumor cell destruction was mediated through signaling pathways, such as the MAPK pathway. In vivo antitumor experiments also demonstrated that the T-rGO@Au scaffold significantly inhibited the growth of tumor cells within 2 weeks. Thus, the T-rGO@Au scaffold provides a new treatment strategy for the development of implantable scaffolds for bone tumor defects.

A novel conjugated polymer synthesized via a noble metal-free catalyst in photothermal therapy of hepatocellular carcinoma mediated by second near-infrared (NIR-II) laser

Photothermal therapy (PTT) utilizes photothermal materials to convert light energy into heat under external light irradiation, effectively killing cancer cells. Therefore, the efficacy of PTT is largely determined by the photothermal conversion efficiency of the material. In this study, we developed a novel ladder-type conjugated polymer, PPAPA, via a phenazine ring fusion reaction. PPAPA exhibits a high photothermal conversion efficiency of 75.2 % under 1064 nm laser irradiation, comparable to the benchmark organic photothermal agent SWCNT. Notably, the synthesis of PPAPA avoids the use of noble metal catalysts, eliminating potential biotoxicity caused by residual catalysts and ensuring optimal photothermal stability and efficiency. Furthermore, PPAPA demonstrates efficient photothermal conversion under near-infrared II (NIR-II) 1064 nm laser irradiation, enabling deeper tissue penetration and reduced tissue absorption. This work comprehensively investigates the photothermal properties of PPAPA and evaluates its efficacy in tumor PTT, demonstrating its potential as a novel and effective therapeutic strategy for cancer treatment, offering new hope for patients.

NIR-II Emissive Persistent Neutral π-Radical with Rapid Doublet Internal Conversion for Efficient Cancer Photothermal Theranostics

Organic radicals are considered prospective materials for near-infrared (NIR) photothermal applications, however, sustainability remains the major obstacle of recently reported ionic radical photothermal agents. This work achieved robust sustainability on a series of neutral π-radicals through rational design donor (D)-acceptor (A). With efficient doublet internal conversion, 10H-spiro(acridine-9,9'-fluorene) (SFA)-BTM presented strong NIR absorption extended to 1000 nm and efficient non-radiative relaxation. SFA-BTM nanoparticles (NPs) realized comparable NIR-I photothermal conversion efficiency (PCE) and photoacoustic sensitivity. Also, the π-radical NPs displayed NIR-II emission and achieved high-resolution whole-body angiography for the first time by the NIR-II bioimaging. Ultimately, the photothermal capabilities are confirmed in an orthotopic bone tumor model by effective ablation of cancer cells in vitro and inhibition of the deterioration of tumor in vivo. This research offers a new horizon in the conception and development of sustainable organic radicals for effective NIR-II imaging and theranostics applications.

Regio-isomerization Optimization Strategy for Photosensitizers: Achieving Ultrahigh Type I Reactive Oxygen Species Generation to Enhance Cancer Photoimmunotherapy

Phototherapy, renowned for its noninvasiveness, is widely employed in tumor treatment. However, the tumor microenvironment is usually hypoxic, with insufficient reactive oxygen species (ROS) production, severely limiting its application. Herein, we introduce a regio-isomerization optimization strategy and have synthesized four regio-isomeric photosensitizers featuring a donor-acceptor (D-A) configuration by tactically varying the linkage sites between D and A. Among them, TAF-3 with excellent photostability has an ultrahigh type I ROS production efficiency (4.79 times that of methylene blue) and a photothermal conversion efficiency of 41.7%. TAF-3 improves the conjugation degree; produces an appropriate intramolecular charge transfer effect, which enhances its optical properties and phototherapeutic efficiency; and promotes a stronger immune cell death effect, reducing postoperative melanoma recurrence by 60%. Overall, the optical attributes of D-A type photosensitizers can be tailored through the precision modulation of regio-isomerization, offering a promising avenue for the advancement of clinical photosensitizers suitable for phototherapy.

Molecular light-to-heat conversion promotes orthogonal synthesis and assembly of metal-organic frameworks

Temperature is a fundamental parameter in any chemical process, affecting reaction rates, selectivity and more. In this regard, photon-assisted heat generation for chemical reactions utilizing photothermal materials is emerging as an exciting tool for innovative research. Herein, we develop a synthesis and in-situ assembly strategy for metal-organic frameworks (MOFs) based on the distinct heating of photothermal materials under visible light. A simple cobalt chloride molecular complex is utilized as an efficient and stable light-to-heat converter for initial MOF formation. A thorough investigation of the assembly mechanism reveals the key role photothermal conversion has in the synthesis of the superstructures. Finally, palladium nanoparticles (PdNPs) are utilized as competing photothermal agents (PTAs) shedding light on the dynamics between different heat sources within a reaction and resulting in MOF-NP composites. This work highlights the versatility of the photothermal approach in the synthesis of advanced materials introducing a promising route to the micro/nano assembly of different materials.

NIR-II photothermal therapy combined with activatable immunotherapy against the recurrence and metastasis of orthotopic triple-negative breast cancer

It remains a clinical challenge to treat triple-negative breast cancer due to its aggressiveness and metastasis. Photothermal therapy (PTT) in combination with checkpoint blockade immunotherapy offers a promising strategy for such intractable tumors. In this study, a second near-infrared (NIR-II) photothermal agent (PCD NPs) and a tumor microenvironment-activatable nanoprodrug (NLG NPs) for indoleamine 2,3-dioxygenase 1 (IDO-1) blockade have been designed for the therapy of orthotopic triple-negative breast cancer. The NIR-II absorption of PCD NPs can guarantee the high penetration depth of the laser during PTT. At the same time, NLG NPs can be decomposed into the NLG919 monomer in the tumor microenvironment, which can effectively strengthen the immunogenic cell death-induced immune response. NIR-II PTT in synergy with IDO-1 blockade can effectively inhibit tumor growth and prevent tumor recurrence and metastasis. This work thus provides a safe, efficient and feasible method for the treatment of malignant tumors.

Self-Assembled Peptide-Gold Nanoparticle 1D Nanohybrids Functionalized with GHK Tripeptide for Enhanced Wound-Healing and Photothermal Therapy

Glycyl-l-histidyl-l-lysine (GHK) tripeptides are known for their remarkable therapeutic potential, including wound-healing, anti-inflammatory activity, and cellular regeneration. However, their clinical application has been significantly hindered by poor biological stability and limited efficacy in a physiological medium. In this study, we introduce a sophisticated approach to overcome these limitations by developing supramolecular peptide nanofiber-gold (Au) nanoparticle (NP) hybrids functionalized with GHK tripeptides. By strategically manipulating peptide self-assembly and NP integration, we demonstrated a useful platform that enhances both therapeutic efficacy and material stability. Our methodology involves the precise engineering of 9-fluorenylmethoxycarbonyl-diphenylalanine scaffolds with GHK and KHG tripeptides, enabling robust nanofibril formation through π-π stacking and hydrogen bonding. Critically, we discovered that the specific amino acid sequence significantly influences the surface exposure of lysine, directly impacting the nanohybrid's wound-healing capabilities. The resultant nanohybrids exhibit exceptional characteristics: Au NPs are spatially confined within the peptide nanofibers, achieving a remarkably uniform size distribution of approximately 3 nm. These nanohybrids demonstrate superior near-infrared (NIR) light absorption and photothermal conversion efficiency, enabling effective eradication of cancer cells and organoids killing under NIR irradiation. This dual-functional nanohybrid integrates biocompatible and enzymatically degradable peptide scaffolds to achieve synergistic wound-healing and cancer-killing effects. By mitigating the cytotoxicity and biodegradability issues associated with conventional photothermal agents, our system provides a promising strategy to improve postoperative cancer therapy and promote tissue regeneration. This work highlights the potential of peptide-inorganic nanohybrids in advancing multifunctional therapeutic platforms for cancer treatment and tissue repair.

Biomimetic-Nanoparticle-Enhanced Photothermal Immunotherapy: Targeted Delivery of Near-Infrared Region II Agents and Immunoadjuvants for Tumor Immunogenicity

Advancing at the cutting edge of oncology, the synergistic application of photothermal therapy coupled with immunotherapy is rapidly establishing itself as an innovative and potent strategy against cancer. A critical challenge in this domain is the precise and efficient targeting of tumor tissues with photothermal agents and immunoadjuvants while minimizing interference with healthy tissues. In this paper, we introduce an ingenious biomimetic nanoparticle platform, cancer cell membrane coated F127/(R837 and IR1048) (CFRI) nanoparticles encapsulating a near-infrared region II photothermal agent, IR1048, and an immunostimulatory molecule, R837, with their surface modified using membranes derived from tumor cells, conferring exceptional specificity for tumor targeting. CFRI nanoparticles demonstrated an extraordinary photothermal conversion efficiency of 49%, adeptly eradicating in situ tumors. This process also triggered the release of damage-associated molecular patterns, thereby activating dendritic cells and catalyzing the maturation and differentiation of T cells, initiating a robust immune response. In vivo animal models substantiated that the CFRI-mediated synergistic photothermal and immunotherapeutic strategy markedly suppressed the proliferation of in situ tumors and provoked a vigorous systemic immune response, effectively curtailing the metastasis and recurrence of distant tumors. The successful development of the CFRI nanoparticle system offers a promising horizon for future clinical translations and pioneering research in oncology.

Multidimensional applications of prussian blue-based nanoparticles in cancer immunotherapy

Immunotherapy holds notable progress in the treatment of cancer. However, the clinical therapeutic effect remains a significant challenge due to immune-related side effects, poor immunogenicity, and immunosuppressive microenvironment. Nanoparticles have emerged as a revolutionary tool to surmount these obstacles and amplify the potency of immunotherapeutic agents. Prussian blue nanoparticles (PBNPs) exhibit multi-dimensional immune function in cancer immunotherapy, including acting as a nanocarrier to deliver immunotherapeutic agents, as a photothermal agent to improve the efficacy of immunotherapy through photothermal therapy, as a nanozyme to regulate tumor microenvironment, and as an iron donor to induce immune events related to ferroptosis and tumor-associated macrophages polarization. This review focuses on the advances and applications of PBNPs in cancer immunotherapy. First, the biomedical functions of PBNPs are introduced. Then, based on the immune function of PBNPs, we systematically reviewed the multidimensional application of PBNPs in cancer immunotherapy. Finally, the challenges and future developments of PBNPs-based cancer immunotherapy are highlighted.

Nanomedicine's shining armor: understanding and leveraging the metal-phenolic networks

Metal-phenolic networks (MPNs), which comprise supramolecular amorphous networks formed by interlinking polyphenols with metal ions, garner escalating interest within the realm of nanomedicine. Presently, a comprehensive synthesis of the cumulative research advancements and utilizations of MPNs in nanomedicine remains absent. Thus, this review endeavors to firstly delineate the characteristic polyphenols, metal ions, and their intricate interaction modalities within MPNs. Subsequently, it elucidates the merits and demerits of diverse synthesis methodologies employed for MPNs, alongside exploring their potential functional attributes. Furthermore, it consolidates the diverse applications of MPNs across various nanomedical domains encompassing tumor therapy, antimicrobial interventions, medical imaging, among others. Moreover, a meticulous exposition of the journey of MPNs from their ingress into the human body to eventual excretion is provided. Lastly, the persistent challenges and promising avenues pertaining to MPNs are delineated. Hence, this review offering a comprehensive exposition on the current advancements of MPNs in nanomedicine, consequently offering indirect insights into their potential clinical implementation.

Ultra-pH-sensitive nanoplatform for precise tumor therapy

The emergence of precision cancer treatment has triggered a paradigm shift in the field of oncology, facilitating the implementation of more effective and personalized therapeutic approaches that enhance patient outcomes. The pH of the tumor microenvironment (TME) plays a pivotal role in both the initiation and progression of cancer, thus emerging as a promising focal point for precision cancer treatment. By specifically targeting the acidic conditions inherent to the tumor microenvironment, innovative therapeutic interventions have been proposed, exhibiting significant potential in augmenting treatment efficacy and ameliorating patient prognosis. The concept of ultra-pH-sensitive (UPS) nanoplatform was proposed several years ago, demonstrating exceptional pH sensitivity and an adjustable pH transition point. Subsequently, diverse UPS nanoplatforms have been actively explored for biomedical applications, enabling the loading of fluorophores, therapeutic drugs, and photosensitizers. This review aims to elucidate the design strategy and response mechanism of the UPS nanoplatform, with a specific emphasis on its applications in surgical therapy, immunotherapy, drug delivery, photodynamic therapy, and photothermal therapy. The potential and challenges of translating in the clinic on UPS nanoplatforms are finally explored. Thanks to its responsive and easily modifiable nature, the integration of multiple functional units within a UPS nanoplatform holds great promise for future advancements in tumor precision theranositcs.

Polydopamine Decorated Hyaluronic Acid Clusters for Tumor Cell Targeting Combination Therapy via Template Self-Consumption Methods

Photothermal-chemodynamic-chemotherapy (PTT-CDT-CT) combination therapy significantly enhances the therapeutic efficacy against tumors. However, synthesizing PTT-CDT-CT nanosystems is complex, typically requiring the preparation and conjugation of three components into a single carrier. To overcome this challenge, a facile template self-consumption method is developed. In this approach, hyaluronic acid (HA), recognized for its tumor cell targeting properties, chelates with Cu2+ to form Cu-HA, which then transforms into CuO2@HA cluster templates. These templates self-consume gradually, producing ·OH and Cu2+, which catalyze the rapid polymerization of dopamine and coordinate with polydopamine respectively, enhancing the photothermal conversion efficiency. After gossypol loading, GPDA@HA clusters are formed, achieving high gossypol loading efficiency due to π-π stacking between gossypol and PDA, as well as coordination between gossypol and Cu2+. The GPDA@HA clusters are effectively internalized by tumor cells through endocytosis, mediating the synergistic damage or inhibition of intracellular proteins, and nucleic acids against tumor cells via PTT, CDT, and CT. Crucially, the synergism of PTT-CDT-CT combination therapy far surpasses those of a single modality. This work introduces a new pathway for the synthesis of PTT-CDT-CT nanosystems, avoiding the conventional synthesis and loading of different therapeutic agents, and provides insights into developing personalized drug combination therapies with high efficacy.

Supramolecular Synthesis of Dithienylethene-Albumin Complexes for Enhanced Photoswitching In Photoacoustic Imaging-Guided Near-Infrared Photothermal Therapy

Photoswitchable molecules can transit between two distinct isomers, enabling them to perform highly controllable imaging and therapeutic functions under certain laser irradiation. Dithienylethenes (DTEs), a class of photoswitchable molecules, exhibit strong thermal stability and high fluorescence quantum yield. However, the short excitation wavelength poses a significant challenge for the application of DTEs in photocontrolled imaging and therapy. Therefore, the development of DTE-based derivatives or hybrid materials with near-infrared (NIR) excitation is of great importance. In this study, two novel DTE derivatives are synthesized, whose closed-ring isomers exhibit strong absorption in the NIR region. Compared with a DTE derivative previously reported and commercially available ones, these two DTE derivatives show higher photoswitching efficiency and extended absorption wavelength. Notably, the supramolecular assembly between DTE derivatives and albumin confers NIR-activated photothermal switching ability on DTE molecules in aqueous solution. In addition, DTE-albumin nanoparticles are further developed to enable photoswitchable photoacoustic imaging (PAI) and photothermal therapy (PTT) for in vivo antitumor applications. Finally, by integrating a thermo-responsive free radical initiator into DTE-albumin nanoparticles, photoswitchable PTT and chemodynamic therapy (CDT) are achieved, effectively inhibiting tumor growth and preventing tumor metastasis.

Rational design of AIEgens through π-bridge engineering for dual-modal photodynamic and photothermal therapy

A series of aggregation-induced emission luminogens (AIEgens) with donor-π-acceptor (D-π-A) architecture were rationally designed and synthesized through π-bridge engineering for dual-modal photodynamic and photothermal therapy. The AIEgens (TPT, TFT, and TTT) were constructed using methoxy-substituted tetraphenylene as the electron donor and tricyanofuran as the electron acceptor, connected via different π-bridges (phenyl, furan, or thiophene). These compounds exhibited red-shifted absorption (460-545 nm) and emission (712-720 nm) with remarkable aggregation-induced emission characteristics. Among them, TTT demonstrated superior photophysical properties and was successfully encapsulated into amphiphilic calixarene-based nanoparticles (T@Q NPs) with uniform morphology. The T@Q NPs showed efficient reactive oxygen species generation and photothermal conversion (η = 6.98 %), enabling effective tumor cell ablation through combined photodynamic and photothermal therapy. In vivo studies revealed that T@Q NPs achieved 70 % tumor growth inhibition in 4T1 tumor-bearing mice without obvious systemic toxicity. This work presents an effective strategy for designing AIEgens-based phototherapeutic agents through π-bridge engineering, offering promising candidates for clinical translation in tumor phototherapy.

Mini Review On: The Roles of DNA Nanomaterials in Phototherapy

DNA-based functional nanomaterials are distinguished by their structural designability and functional controllability, making them particularly attractive in the biomedical field. Using DNA nanomaterials for cancer treatment through synergistic approaches combining photodynamic therapy and photothermal therapy has garnered significant attention. This growing interest has driven the active development of various DNA nanomaterials tailored for integrated strategies targeting cancer, including phototherapy, chemotherapy, etc. This review provides an overview of DNA nanoplatforms employed in phototherapy and synergistic therapy for cancer treatment. It highlights recent advances in DNA nanoplatforms that leverage multifaceted synergy to enhance phototherapeutic efficacy. It also offers a new perspectives and clinical application potential of DNA nanomaterials in synergistic phototherapy for malignant tumors, focusing on developments in recent years and potential directions for future research and applications.

Biodegradable semiconducting polymer nanoparticles for phototheranostics

Semiconducting polymer nanoparticles (SPNs) have been widely applied for phototheranostics. However, the disadvantage of in vivo long-term metabolism greatly suppresses the clinical application of SPNs. To improve the metabolic rate and minimize the long-term toxicity of SPNs, biodegradable semiconducting polymers (BSPs), whose backbones may be degraded under certain conditions, have been designed. This review summarizes recent advances in BSP-constructed nanoparticles (BSPNs) for phototheranostics. BSPs are divided into two categories: conjugated backbone degradable BSPs (CBD-BSPs) and non-conjugated backbone degradable BSPs (NCBD-BSPs), based on the feature of chemical structure. The biological applications, including cancer imaging and combination therapy, of these BSPNs are described. Finally, the conclusion and future perspectives of this field are discussed.

Bowl-Shaped Anthracene-Fused Antiaromatic Ni(II) Norcorrole: Synthesis, Structure, Assembly with C60, and Photothermal Conversion

The synthesis of bowl-shaped antiaromatic molecules is challenging because the molecular distortion further destabilizes these already inherently reactive molecules. Here, we report the synthesis and properties of bowl-shaped fused anthrylnorcorroles that exhibit near-infrared (NIR) absorption reaching 1900 nm. The oxidation of meso-anthryldibromodipyrrin provides fused anthryldibromodipyrrin, which was converted to the fused mono- and bisanthrylnorcorroles through Ni(0)-mediated intramolecular coupling with a bis(dibromodipyrrin) Ni(II) complex. Single-crystal X-ray diffraction analyses revealed bowl-shaped structures for the fused mono- and bisanthrylnorcorroles, which enables them to act as suitable receptors for C60 with bonding constants of 2.89×103 M-1 and 1.59×103 M-1, respectively. The formation of a 1 : 1 complex between the fused monoanthrylnorcorrole and C60 was confirmed by single-crystal X-ray diffraction analysis. The effective expansion of the π-conjugation through the triple fusion of the norcorrole with the anthracene units substantially enhances the near-infrared absorption bands, which endows these anthrylnorcorroles with effective photothermal conversion.

Random Copolymerization: An Efficient Strategy for Significantly Enhancing Photothermal Performance Through Synergistic Open-Shell Radical and TICT Effects

Currently, photothermal (PT) polymers are gaining increasing attention in water evaporation, photocatalysis and photothermal therapy. However, high-performance PT polymers often require conjugated backbones and/or large fused units, which can impede non-radiative decay and lead to suboptimal PT performance. The development of general strategies for preparing high-performance PT polymers remains a significant challenge. In this paper, the high-performance donor-acceptor (D-A) random copolymers, named PBT4T-BBT-x (x = 0, 5, 10, 20 and 100), were fabricated by cross-mixing bithiophene donors with benzothiadiazole (BT) and benzodithiadiazole (BBT) acceptors. Notably, when the ratios of BT and BBT are finely tuned, the polymers exhibit significantly controllable open-shell radical effects and twisted intermolecular charge transfer (TICT) states. The synergistic effects of radicals and TICT states notably enhanced the PT performance of random copolymers. Specifically, when the proper ratios of BBT units are used, the photothermal conversion efficiency (PTCE) is remarkably increased from 21.7% to 58.5%, and the PT temperature obviously increases from 150 °C to 232 °C under 808 nm laser irradiation. Furthermore, the random copolymers exhibit good water evaporation rates. We propose that this strategy provides a valuable synthesis pathway for generating high-performance photothermal therapy and water evaporation materials.

Metal-Bridging Cyclic Bilatriene Analogue Affords Stable π-Radicaloid Dyes with Near-Infrared II Absorption

Stable neutral metal radicaloid complexes have been synthesized from a modified tetrapyrrolic pigment, bilatriene, with iridium(I) and rhodium(I) cyclooctadiene (COD) synthons. The bilatriene skeleton contains α-linked conjugated pyrrole units, whereas an N-confused analogue used in this work possesses β-linked pyrrole moieties at the terminal, demonstrating a unique metal binding capability. Unprecedentedly, the metal-COD cations are accommodated at the outer nitrogen sites, which induced the formation of open-shell metal-radicaloid species. The resulting compounds are highly stable under ambient conditions and demonstrated facile redox conversion to afford the corresponding cation and anion species. Furthermore, the radicaloid complexes showed a distinct second near-infrared absorption (NIR-II) capability extending up to 1500 nm along with high photostability. These features emphasized that the complexes can be potential NIR-II light-responsible photothermal and photoacoustic imaging contrast agents based on the metal-radicaloid dye platform.

Transition metal complexes: next-generation photosensitizers for combating Gram-positive bacteria

The rise of antibiotic-resistant Gram-positive bacterial infections poses a significant threat to public health, necessitating the exploration of alternative therapeutic strategies. A photosensitizer (PS) can convert energy from absorbed photon into reactive oxygen species (ROS) for damaging bacteria. This photoinactivation action bypassing conventional antibiotic mechanism is less prone to resistance development, making antibacterial photodynamic therapy (aPDT) highly efficient in combating Gram-positive bacteria. Photodynamic transition metal complexes leveraging the unique properties of metals to enhance the aPDT activity are the next-generation PS. This review provides an overview of metal-based PS for combating Gram-positive bacteria. Based on the structures, these metal-PS could be mainly classified as metal-tetrapyrrole derivatives, ruthenium complexes, iridium complexes, and zinc complexes. PS based on complexes of other transition metals such as silver, cobalt, and rhenium are also presented. Finally, we summarize the advantages and shortcomings of these metal- PS, conclude some critical aspects impacting their aPDT performances and give a perspective on their future development.

The anti-biofilm effect of α-amylase/glycopolymer-decorated gold nanorods

The continuous evolution of bacteria and the formation of biofilm have exacerbated resistance issues, highlighting the urgent need for new antibacterial materials. In this study, L-fucose was polymerized to synthesize thiolated poly(2-(L-fucose) ethyl methacrylate) (PFEMA-SH), which was subsequently co-modified with α-amylase onto gold nanorods (GNR) to prepare the antibacterial nanoparticle composite, GNR-Amy-PFEMA (G-A-P). These nanomaterials exhibit both photothermal and enzymatic properties, enabling G-A-P to effectively sterilize and disperse biofilm. Under near-infrared light irradiation, the temperature of G-A-P composite increases significantly, leading to bacterial cell damage and biofilm disruption. The G-A-P composite demonstrated nearly 100 % eradication of planktonic bacteria after 5 min of irradiation and achieved a 70.9 % reduction in mature biofilm biomass, with a 3.37-log decrease in the number of bacteria within the biofilm. These composites display strong antimicrobial activity and hold great potential for the removal of Pseudomonas aeruginosa biofilm. Furthermore, the ability of G-A-P to reduce biofilm formation without the use of traditional antibiotics suggests that it may offer an antibiotic-free alternative for managing biofilm-related infections.

Quinoidal Semiconductor Nanoparticles for NIR-II Photoacoustic Imaging and Photoimmunotherapy of Cancer

Photoagents with ultra-high near-infrared II (NIR-II) light energy conversion efficiency hold great promise in tumor phototherapy due to their ability to penetrate deeper tissues and minimize damage to surrounding healthy cells. However, the development of NIR-II photoagents remain challenging. In this study, an all-fused-ring quinoidal acceptor-donor-acceptor (A-D-A) molecule, SKCN, with a BTP core is synthesized, and nanoparticles named FA-SNPs are prepared. The unique quinoidal structure enhances π-electron delocalization and bond length uniformity, significantly reducing the bandgap of SKCN, resulting in strong NIR-II absorption, a high molar extinction coefficient, and a photothermal conversion efficiency of 75.14%. Enhanced molecular rigidity also facilitates efficient energy transfer to oxygen, boosting reactive oxygen species generation. By incorporating the immunomodulator R848, FA-SRNPs nanoparticles are further developed, effectively modulating the tumor immune microenvironment by reducing Tregs and M-MDSCs infiltration, promoting dendritic cell maturation, M1 macrophage polarization, and activating CD8+ T cells and NK cells. Comprehensive studies using orthotopic ovarian cancer models demonstrated strong tumor targeting, photoacoustic imaging capabilities, and significant tumor suppression and metastasis inhibition, and also showing excellent therapeutic efficacy in an orthotopic breast cancer model. This study provides strong evidence for the potential application of quinoidal A-D-A molecules in cancer photoimmunotherapy.

A One-Stone-Two-Birds Strategy for Intervertebral Disc Repair: Constructing a Reductive Chelation Hydrogel to Mitigate Oxidative Stress and Promote Disc Matrix Reconstruction

Intervertebral disc degeneration (IVDD) is characterized by fibrosis of nucleus pulposus (NP) cells and accelerated surrounding extracellular matrix catabolism. Bioactive hydrogels have shown significant potential in regulating cellular functions and tissue homeostasis. In this work, a dynamic hydrogel (HA-NCSN/Cu) is designed via the reductive chelation of hyaluronic acid grafted with thiourea (HA-NCSN) and Cu2+. The reductivity of the grafted thiourea groups of HA-NCSN can quickly reduce part of the chelated Cu2+ to Cu+. Therefore, during the gelation process, the color of hydrogel become dark immediately, which endowed hydrogel with remarkable photothermal effect. The abundant thiourea groups inside hydrogel can effectively scavenge reactive oxygen species to mitigate the inflammatory stress of NP cells. RNA sequencing analysis further reveals that glutathione signaling pathway is significantly altered. Meanwhile, mild photothermal therapy could activate the TGF-β/Smad pathway in NP cells, promoting the expression and secretion of Aggrecan and Collagen II. Ultimately, the combined modulation of inflammation alleviation and matrix regeneration achieves the restoration of the structure and function of the damaged intervertebral disc, which is also strongly demonstrated by the in vivo animal experiments. All of these results demonstrate the great potential of the dynamic HA-NCSN/Cu hydrogel in IVDD treatment.

Tumor microenvironment ameliorative and adaptive nanoparticles with photothermal-to-photodynamic switch for cancer phototherapy

The notorious tumor microenvironment (TME) usually becomes more deteriorative during phototherapeutic progress that hampers the antitumor efficacy. To overcome this issue, we herein report the ameliorative and adaptive nanoparticles (TPASIC-PFH@PLGA NPs) that simultaneously reverse hypoxia TME and switch photoactivities from photothermal-dominated state to photodynamic-dominated state to maximize phototherapeutic effect. TPASIC-PFH@PLGA NPs are designed by incorporating oxygen-rich liquid perfluorohexane (PFH) into the intraparticle microenvironment to regulate the intramolecular motions of AIE photosensitizer TPASIC. TPASIC exhibits a unique aggregation-enhanced reactive oxygen species (ROS) generation feature. PFH incorporation affords TPASIC the initially dispersed state, thus promoting active intramolecular motions and photothermal conversion efficiency. While PFH volatilization leads to nanoparticle collapse and the formation of tight TPASIC aggregates with largely enhanced ROS generation efficiency. As a consequence, PFH incorporation not only currently promotes both photothermal and photodynamic efficacies of TPASIC and increases the intratumoral oxygen level, but also enables the smart photothermal-to-photodynamic switch to maximize the phototherapeutic performance. The integration of PFH and AIE photosensitizer eventually delivers more excellent antitumor effect over conventional phototherapeutic agents with fixed photothermal and photodynamic efficacies. This study proposes a new nanoengineering strategy to ameliorate TME and adapt the treatment modality to fit the changed TME for advanced antitumor applications.

Preclinical advance in nanoliposome-mediated photothermal therapy in liver cancer

Liver cancer is a highly lethal malignant tumor with a high incidence worldwide. Therefore, its treatment has long been a focus of medical research. Although traditional treatment methods such as surgery, radiotherapy, and chemotherapy have increased the survival rate of patients, their efficacy remains unsatisfactory owing to the nonspecific distribution of drugs, high toxicity, and drug resistance of tumor tissues. In recent years, the application of nanotechnology in the medical field has opened a new avenue for the treatment of liver cancer. Among these treatment methods, photothermal therapy (PTT) based on nanoliposomes has attracted wide attention owing to its unique targeting and high efficiency. This article reviews the latest preclinical research progress of nanoliposome-based PTT for liver cancer and its metastasis, discusses the preclinical challenges in this field, and proposes directions for improvement, with the aim of improving the effectiveness of liver cancer treatment.

A supramolecular diazapyrene radical assembly with NIR absorption for selective photothermal antibacterial activity

A supramolecular radical assembly that can be induced in situ by facultative anaerobic bacteria has been reported and used for selective near-infrared (NIR) photothermal antibacterial action. Herein, we report the synthesis of a water-soluble diazapyrene derivative (DAPNP), which could be in situ initiated into the corresponding radicals by facultative anaerobic bacteria, such as E. coli or S. aureus. The introduction of cucurbit[10]uril (CB[10]) alters the stacking mode of the diazapyrene radical cations, resulting in a redshift of their characteristic absorption peak from the visible region to the NIR region. Under 660 nm laser irradiation, the in situ-induced supramolecular radical assembly exhibits great photothermal conversion properties and achieves highly efficient antibacterial activity (up to 98%). In contrast, with the aerobic B. subtilis it is difficult to induce the formation of diazapyrene radical cations in situ and maintain good activity under light irradiation. In addition, DAPNP@CB[10] exhibits excellent biocompatibility and has great potential as an intelligent photothermal material for antibacterial applications.

Effective Antitumor Synergistic Treatment with Fiber-Photothermal Therapy and Heat Shock Protein Inhibitors

Effective treatment of malignant tumors remains a thorny issue in current medicine. As a new type of anticancer strategy, photothermal therapy (PTT) has attracted tremendous attention due to its favorable therapeutic effectiveness, high spatial-temporal controllability, and low occurrence of side effects. However, the efficacy of PTT is significantly reduced due to the limited penetration of light and heat-induced overexpression of heat shock protein (Hsp). Herein, we propose an antitumor synergistic therapy that combines fiber-optic PTT and Hsp inhibitors. A rare-earth-doped optical fiber was used as the PTT actuator, and the Hsp inhibitor AT533 was loaded on the fiber surface by use of a hydrogel layer. PTT fibers can be guided to reach tumor lesions directly without being subject to the light penetration limit. The Hsp inhibitor can be released upon the softening of the hydrogel layer under photoheating to deactivate Hsp in the tumor and thus reduce the resistance of the tumor to PTT. This synergistic treatment enhanced the effect of PTT and successfully eradicated tumors in colorectal cancer (CRC) xenograft mouse models, providing a feasible way to realize antitumor and antirecurrence treatment. More importantly, the success of the synergistic treatment of PTT and Hsp inhibition opens new avenues for the development of multimodal and multitype synergistic fiber-optic treatments, which offer pronounced enhancement of therapeutic effectiveness for treating cancer.