Dual gatekeepers-modified mesoporous organic silica nanoparticles for synergistic photothermal-chemotherapy of breast cancer

HYPOTHESIS

Construction of dual gatekeepers-functionalized mesoporous organic silica nanoparticles (MONs) with both physical and chemical mechanisms for modulated drug delivery properties provides one solution to the extracellular stability vs. intracellular high therapeutic efficiency of MONs that hold great potential for clinical translations.

EXPERIMENTS

We reported herein facile construction of diselenium-bridged MONs decorated with dual gatekeepers, i.e., azobenzene (Azo)/polydopamine (PDA) for both physical and chemical modulated drug delivery properties. Specifically, Azo can act as a physical barrier to block DOX in the mesoporous structure of MONs for extracellular safe encapsulation. The PDA outer corona serves not only as a chemical barrier with acidic pH-modulated permeability for double insurance of minimized DOX leakage in the extracellular blood circulation but also for inducing a PTT effect for synergistic PTT and chemotherapy of breast cancer.

FINDINGS

An optimized formulation, DOX@(MONs-Azo3)@PDA resulted in approximately 1.5 and 2.4 fold lower IC50 values than DOX@(MONs-Azo3) and (MONs-Azo3)@PDA controls in MCF-7 cells, respectively, and further mediated complete tumor eradication in 4T1 tumor-bearing BALB/c mice with insignificant systematic toxicity due to the synergistic PTT and chemotherapy with enhanced therapeutic efficiency.

Near-infrared absorbing semiconducting polymer nanomedicines for cancer therapy

As a new type of organic optical nanomaterials, semiconducting polymer nanoparticles (SPNs) have the advantages of good optical characteristics and photostability, low toxicity concerns, and relatively simple preparation processes. Particularly, near-infrared (NIR) absorbing SPNs have shown a great promise in biomedicine. In addition to acting as nanoprobes for molecular imaging, these SPNs can produce local heat and reactive oxygen species with the stimulation of NIR light, allowing photothermal therapy (PTT) and photodynamic therapy (PDT), respectively. Herein, we summarize the recent development of SPN-based nanomedicines for cancer therapy. The rational designs of SPNs for enhanced PTT, PDT, or combinational PTT/PDT to achieve effective ablation of tumor tissues are highlighted. Via loading/conjugating SPNs with other therapeutic elements (such as chemotherapeutic drugs and immunotherapeutic agents), phototherapy-combined chemotherapy or immunotherapy can be realized, which is then discussed. In especial, the constructions of SPN-based nanomedicines for NIR photoactivatable chemotherapy and immunotherapy are introduced with representative examples. Finally, we discuss the current challenges and key concerns of SPNs for their biomedical applications and give an outlook for their future clinical translation. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Engineered photoresponsive biohybrids for tumor therapy

Engineered biohybrids have recently emerged as innovative biomimetic platforms for cancer therapeutic applications. Particularly, engineered photoresponsive biohybrids hold tremendous potential against tumors due to their intriguing biomimetic properties, photoresponsive ability, and enhanced biotherapeutic functions. In this review, the design principles of engineered photoresponsive biohybrids and their latest progresses for tumor therapy are summarized. Representative engineered photoresponsive biohybrids are highlighted including biomolecules-associated, cell membrane-based, eukaryotic cell-based, bacteria-based, and algae-based photoresponsive biohybrids. Representative tumor therapeutic modalities of the engineered photoresponsive biohybrids are presented, including photothermal therapy, photodynamic therapy, synergistic therapy, and tumor therapy combined with tissue regeneration. Moreover, the challenges and future perspectives of these photoresponsive biohybrids for clinical practice are discussed.

Recent Developments in Nanoparticle-Based Photo-Immunotherapy for Cancer Treatment

Phototherapy is an emerging approach for cancer treatment that is effective at controlling the growth of primary tumors. In the presence of light irradiation, photothermal and photodynamic agents that are delivered to tumor sites can induce local hyperthermia and the production of reactive oxygen species, respectively, that directly eradicate cancer cells. Nanoparticles, characterized by their small size and tunable physiochemical properties, have been widely utilized as carriers for phototherapeutic agents to improve their biocompatibility and tumor-targeted delivery. Nanocarriers can also be used to implement various codelivery strategies for further enhancing phototherapeutic efficiency. More recently, there has been considerable interest in augmenting the immunological effects of nanoparticle-based phototherapies, which can yield durable and systemic antitumor responses. This review provides an overview of recent developments in using nanoparticle technology to achieve photo-immunotherapy.

BODIPY as a Multifunctional Theranostic Reagent in Biomedicine: Self-Assembly, Properties, and Applications

The use of boron dipyrromethene (BODIPY) in biomedicine is reviewed. To open, its synthesis and regulatory strategies are summarized, and inspiring cutting-edge work in post-functionalization strategies is highlighted. A brief overview of assembly model of BODIPY is then provided: BODIPY is introduced as a promising building block for the formation of single- and multicomponent self-assembled systems, including nanostructures suitable for aqueous environments, thereby showing the great development potential of supramolecular assembly in biomedicine applications. The frontier progress of BODIPY in biomedical application is thereafter described, supported by examples of the frontiers of biomedical applications of BODIPY-containing smart materials: it mainly involves the application of materials based on BODIPY building blocks and their assemblies in fluorescence bioimaging, photoacoustic imaging, disease treatment including photodynamic therapy, photothermal therapy, and immunotherapy. Lastly, not only the current status of the BODIPY family in the biomedical field but also the challenges worth considering are summarized. At the same time, insights into the future development prospects of biomedically applicable BODIPY are provided.

Near-Infrared Fluorescent Hydroxyapatite Nanoparticles for Targeted Photothermal Cancer Therapy

Near-infrared (NIR) fluorophores have attracted great attention due to their excellent optical and photothermal properties. Among them, a bone-targeted NIR fluorophore (named P800SO3) contains two phosphonate groups, which play important roles in binding with hydroxyapatite (HAP) as the main mineral component of bones. In this study, biocompatible and NIR fluorescent HAP nanoparticles functionalized with P800SO3 and polyethylene glycol (PEG) were readily prepared for tumor-targeted imaging and photothermal therapy (PTT). The PEGylated HAP nanoparticle (HAP800-PEG) demonstrated improved tumor targetability with high tumor-to-background ratios (TBR). Moreover, the HAP800-PEG also showed excellent photothermal properties, and the temperature of tumor tissue reached 52.3 °C under NIR laser irradiation, which could completely ablate the tumor tissue without recurrence. Therefore, this new type of HAP nanoparticle has great potential as a biocompatible and effective phototheranostic material, which enables the use of P800SO3 for targeted photothermal cancer treatment.

Nanomaterials for Skin Cancer Photoimmunotherapy

Skin cancer is one of the most common types of cancer, and its incidence continues to increase. It is divided into two main categories, melanoma and non-melanoma. Treatments include surgery, radiation therapy, and chemotherapy. The relatively high mortality in melanoma and the existing recurrence rates, both for melanoma and non-melanoma, create the need for studying and developing new approaches for skin cancer management. Recent studies have focused on immunotherapy, photodynamic therapy, photothermal therapy, and photoimmunotherapy. Photoimmunotherapy has gained much attention due to its excellent potential outcomes. It combines the advantages of photodynamic and/or photothermal therapy with a systemic immune response, making it ideal for metastatic cancer. This review critically discusses different new nanomaterials' properties and mechanisms of action for skin cancer photoimmunotherapy and the main results obtained in the field.

Multi-Channel Lanthanide Nanocomposites for Customized Synergistic Treatment of Orthotopic Multi-Tumor Cases

Simultaneous photothermal ablation of multiple tumors is limited by unpredictable photo-induced apoptosis, caused by individual intratumoral differences. Here, a multi-channel lanthanide nanocomposite was used to achieve tailored synergistic treatment of multiple subcutaneous orthotopic tumors under non-uniform whole-body infrared irradiation prescription. The nanocomposite reduces intratumoral glutathione by simultaneously activating the fluorescence and photothermal channels. The fluorescence provides individual information on different tumors, allowing customized prescriptions to be made. This enables optimal induction of hyperthermia and dosage of chemo drugs, to ensure treatment efficacy, while avoiding overtherapy. With an accessional therapeutic laser system, customized synergistic treatment of subcutaneous orthotopic cancer cases with multiple tumors is possible with both high efficacy and minimized side effects.

Near-infrared-II-activatable sulfur-deficient plasmonic Bi2S3-x-Au heterostructures for photoacoustic imaging-guided ultrasound enhanced high performance phototherapy

Bismuth sulfide is widely used as an n-type semiconductor material in photocatalytic reactions. However, bismuth sulfide has poor absorption in the near-infrared region and low charge separation efficiency, limiting its application in phototherapy and sonodynamic therapy (SDT). In this study, we successfully synthesized an "all-in-one" phototheranostic nanoplatform, namely Bi₂S_3-x-Au@HA, based on a single second near-infrared (NIR-II) light-responsive Schottky-type Bi₂S_3-x-Au heterostructure for photoacoustic (PA) imaging-guided SDT-enhanced photodynamic therapy (PDT)/photothermal therapy (PTT). Bi₂S_3-x-Au@HA exhibits excellent NIR-II plasmonic and photothermal properties, rendering it with NIR-II PA imaging capabilities for accurate diagnosis. Additionally, the high-density sulfur vacancies constructed on the Bi₂S₃ surface cause it to possess a reduced band gap (1.21 eV) that can act as an electron trap. Using the density functional theory, we confirmed that the light and ultrasound-induced electrons are more likely to aggregate on the Au nanoparticle surface through interfacial self-assembly, which promotes electron-hole separation and enhances photocatalytic activity with increased reactive oxygen species (ROS) generation. With a further modification of hyaluronic acid (HA), Bi₂S_3-x-Au@HA can selectively target cancer cells through HA and CD44 protein interactions. Both in vitro and in vivo experiments demonstrated that Bi₂S_3-x-Au@HA effectively suppressed tumor growth through SDT-enhanced PTT/PDT under a single NIR-II laser and ultrasound irradiation with negligible toxicity. Our findings provide a framework for fabricating Schottky-type heterostructures as single NIR-II light-responsive nanotheranostic agents for PA imaging-guided cancer phototherapy.

Conjugated Polymer Nanoparticles for Tumor Theranostics

Water-dispersible conjugated polymer nanoparticles (CPNs) have demonstrated great capabilities in biological applications, such as in vitro cell/subcellular imaging and biosensing, or in vivo tissue imaging and disease treatment. In this review, we summarized the recent advances of CPNs used for tumor imaging and treatment during the past five years. CPNs with different structures, which have been applied to in vivo solid tumor imaging (fluorescence, photoacoustic, and dual-modal) and treatment (phototherapy, drug carriers, and synergistic therapy), are discussed in detail. We also demonstrated the potential of CPNs as cancer theranostic nanoplatforms. Finally, we discussed current challenges and outlooks in this field.

Intelligent delivery system targeting PD-1/PD-L1 pathway for cancer immunotherapy

The drugs targeting the PD-1/PD-L1 pathway have gained abundant clinical applications for cancer immunotherapy. However, only a part of patients benefit from such immunotherapy. Thus, brilliant novel tactic to increase the response rate of patients is on the agenda. Nanocarriers, particularly the rationally designed intelligent delivery systems with controllable therapeutic agent release ability and improved tumor targeting capacity, are firmly recommended. In light of this, state-of-the-art nanocarriers that are responsive to tumor-specific microenvironments (internal stimuli, including tumor acidic microenvironment, high level of GSH and ROS, specifically upregulated enzymes) or external stimuli (e.g., light, ultrasound, radiation) and release the target immunomodulators at tumor sites feature the advantages of increased anti-tumor potency but decreased off-target toxicity. Given the fantastic past achievements and the rapid developments in this field, the future is promising. In this review, intelligent delivery platforms targeting the PD-1/PD-L1 axis are attentively appraised. Specifically, mechanisms of the action of these stimuli-responsive drug release platforms are summarized to raise some guidelines for prior PD-1/PD-L1-based nanocarrier designs. Finally, the conclusion and outlook in intelligent delivery system targeting PD-1/PD-L1 pathway for cancer immunotherapy are outlined.

Mn-Si-based nanoparticles-enhanced inhibitory effect on tumor growth and metastasis in photo-immunotherapy

The anticancer effect of phototherapy has been limited by some factors, including the easy degradation of photo agents, the complex tumor microenvironment, and the limited immune activation capacity, which impedes its efficiency in inhibiting tumor growth and tumor metastasis. Herein, Mn-doped mesoporous silica nanoparticles were synthesized to load the photo agent of IR 780, which were further coated with Mn (IMM). Notably, the combination of IMM and an 808 nm laser irradiation simultaneously inhibited the growth of primary tumors and distant untreated tumors in a bilateral animal model, which could be attributed to the protection of IMM to IR 780, the regulation functions to the tumor microenvironment, as well as the enhanced immune activation capacity. This work highlighted an alternative strategy for enhancing the inhibitory effect on both tumor growth and tumor metastasis in the combinational anticancer therapy of phototherapy and immunotherapy (photo-immunotherapy).

An oxygen-carrying and lysosome-targeting BODIPY derivative for NIR bioimaging and enhanced multimodal therapy against hypoxic tumors

Cancer treatment modalities have gradually shifted from monotherapies to multimodal therapies. It is still a challenge to develop a synergistic chemo-phototherapy system with relieving tumor hypoxia, specific targeting, and real-time fluorescence tracking. In this study, we designed a multifunctional BODIPY derivative, FBD-M, for synergistic chemo-phototherapy against hypoxic tumors. FBD-M was composed of four parts: 1) The BODIPY fluorophore selected as a theranostic core, 2) A pentafluorobenzene group modified on meso-BODIPY to carry oxygen, 3) A morpholine group hooked to one side of BODIPY served as a lysosome-targeting unit for enhancing antitumor effect, and 4) An aromatic nitrogen mustard group introduced on other side of BODIPY to achieve chemotherapy. After introducing the morpholine and aromatic nitrogen mustard in BODIPY, the conjugate system of BODIPY was also expanded to realize near-infrared (NIR) phototherapy. Finally, FBD-M was obtained by a rational design, which possessed with NIR absorbance and emission, photosensitive activity, oxygen-carrying capability for relieving tumor hypoxia, high photothermal conversion efficiency, good photostability, lysosome targeting, low toxicity, and synergistic chemo-phototherapy against hypoxic tumors. FBD-M had been successfully applied for anticancer in vitro and in vivo. Our study demonstrates that FBD-M can serve as an ideal multifunctional theranostic agents.

Perovskite-Type Manganese Vanadate Sonosensitizers with Biodegradability for Enhanced Sonodynamic Therapy of Cancer

Sonodynamic therapy (SDT) has attracted intensive attention, but is still hindered by low sonosensitization and non-biodegradability of the traditional sonosensitizers. Herein, perovskite-type manganese vanadate (MnVO₃ ) sonosensitizers integrating high reactive oxide species (ROS) production efficiency and appropriate bio-degradability are developed for enhanced SDT. Taking advantage of the intrinsic properties of perovskites such as narrow bandgap and substantial oxygen vacancies, MnVO₃ shows a facile ultrasound (US)-triggered electrons-holes separation and restrained recombination, thus enhancing the ROS quantum yield in SDT. Furthermore, MnVO₃ exhibits a considerable chemodynamic therapy (CDT) effect under the acidic condition probably owing to the presence of manganese and vanadium ions. Due to the presence of high-valent vanadium, MnVO₃ can also eliminate glutathione (GSH) within the tumor microenvironment, which synergistically amplifies the efficacy of SDT and CDT. Importantly, the perovskite structure bestows MnVO₃ with superior biodegradability, which alleviates the long-term presence of residues in metabolic organs after therapeutic actions. Based on these characteristics, US-assisted MnVO₃ achieves an excellent antitumor outcome along with low systemic toxicity. Overall, perovskite-type MnVO₃ may be promising sonosensitizers for highly efficient and safe treatment of cancer. The work attempts to explore the potential utility of perovskites in the design of degradable sonosensitizers.

Photon-Controlled Pyroptosis Activation (PhotoPyro): An Emerging Trigger for Antitumor Immune Response

Pyroptosis refers to the process of gasdermin-mediated lytic programmed cell death (PCD) characterized by the release of pro-inflammatory cytokines. Our knowledge of pyroptosis has expanded beyond the cellular level and now includes extracellular responses. In recent years, pyroptosis has attracted considerable attention due to its potential to induce host immunity. For instance, at the 2022 International Medicinal Chemistry of Natural Active Ligand Metal-Based Drugs (MCNALMD) conference, numerous researchers demonstrated an interest in photon-controlled pyroptosis activation ("PhotoPyro"), an emerging pyroptosis-engineered approach for activating systemic immunity via photoirradiation. Given this enthusiasm, we share in this Perspective our views on this emerging area and expound on how and why "PhotoPyro" could trigger antitumor immunity (i.e., turning so-called "cold" tumors "hot"). In doing so, we have tried to highlight cutting-edge breakthroughs in PhotoPyro while suggesting areas for future contributions. By providing insights into the current state of the art and serving as a resource for individuals interested in working in this area, it is hoped that this Perspective will set the stage for PhotoPyro to evolve into a broadly applicable cancer treatment strategy.

A biomimetic nanoplatform for precise reprogramming of tumor-associated macrophages and NIR-II mediated antitumor immune activation

The therapeutic effects of photothermal therapy (PTT) are dependent on the photothermal conversion efficiency of photothermal agents (PTAs) in tumors and the subsequent activation of the antitumor immune system. However, the insufficient tumor accumulation of current PTAs and the inevitable recruitment of tumor-associated macrophages (TAMs) could further compromise the antitumor activities of PTT. To address these issues, a biomimetic photothermal nanoplatform Au@Fe-PM is developed for the targeted remodeling of TAMs, which promotes the antitumor immunity of PTT. Au nanorods with second near-infrared (NIR-II) absorptions are fabricated to serve as PTAs to induce immunogenic cell death in tumor cells. The ferric hydroxide shell coated on Au nanorods can release iron ions to repolarize M2-like TAMs into the tumoricidal M1 phenotype via P38 and STAT1-mediated signaling pathways. Moreover, the surface decoration of platelet membranes endows biomimetic nanoplatform with enhanced tumor targeting ability for precise tumor ablation and TAM regulation. Consequently, Au@Fe-PM under NIR-II laser irradiation exhibits significantly higher inhibitory effects in a poor immunogenic 4T1 tumor-bearing mouse model with a 50% complete remission rate compared to conventional PTT (0%). By simultaneously reversing the immunosuppressive tumor microenvironment, this biomimetic nanoplatform offers a promising strategy for enhancing the antitumor efficacy of PTT. STATEMENT OF SIGNIFICANCE: The therapeutic effects of current photothermal therapy (PTT) are hindered by the insufficient tumor accumulation of conventional photothermal agents and the recruitment of immunosuppressive tumor-associated macrophages (TAMs) after PTT. Herein, we report a biomimetic iron-based second near-infrared (NIR-II) photothermal nanoplatform (Au@Fe-PM) for targeted TAMs reprogramming and NIR-II mediated anti-tumor immunity. Au@Fe-PM can actively target the tumor site with the help of surface-decorated platelet membranes. Meanwhile, iron ions would be released from Au@Fe-PM in acidic lysosomes to reprogram TAMs into tumoricidal M1-like macrophages, which promotes the antitumor responses elicited by NIR-II PTT, thereby contributing to remarkable tumor inhibitory effects, with 50% higher complete remission rate than that of conventional PTT.

Metal-Organic Frameworks Applications in Synergistic Cancer Photo-Immunotherapy

Conventional cancer therapies, such as radiotherapy and chemotherapy, can have long-term side effects. Phototherapy has significant potential as a non-invasive alternative treatment with excellent selectivity. Nevertheless, its applicability is restricted by the availability of effective photosensitizers and photothermal agents, and its low efficacy when it comes to avoiding metastasis and tumor recurrence. Immunotherapy can promote systemic antitumoral immune responses, acting against metastasis and recurrence; however, it lacks the selectivity displayed by phototherapy, sometimes leading to adverse immune events. The use of metal-organic frameworks (MOFs) in the biomedical field has grown significantly in recent years. Due to their distinct properties, including their porous structure, large surface area, and inherent photo-responsive properties, MOFs can be particularly useful in the fields of cancer phototherapy and immunotherapy. MOF nanoplatforms have successfully demonstrated their ability to address several drawbacks associated with cancer phototherapy and immunotherapy, enabling an effective and low-side-effect combinatorial synergistical treatment for cancer. In the coming years, new advancements in MOFs, particularly regarding the development of highly stable multi-function MOF nanocomposites, may revolutionize the field of oncology.

Photo-/piezo-activated ultrathin molybdenum disulfide nanomedicine for synergistic tumor therapy

Molybdenum disulfide (MoS₂), as a transition metal dichalcogenide, has attracted tremendous attention owing to its remarkable electronic, physical, and chemical properties. In this study, based on the energy-converting nanomedicine, we report multifunctional two-dimensional (2D) MoS₂ nanosheets with inherent plasmonic property and piezocatalytic activity for imaging-guided synergistic tumor therapy. MoS₂ nanosheets display strong plasmon resonances in the near-infrared (NIR) region, especially in the second NIR biological window, possessing a notable light energy to heat effect under 1064 nm laser irradiation, which not only serves as a robust photothermal agent for cancer cell ablation but also acts as a contrast-enhanced agent for thermal imaging and photoacoustic imaging. Meanwhile, MoS₂ nanosheets feature a remarkable piezotronic effect, exhibiting mechanical vibration energy to electricity under the stimulation of ultrasound-mediated microscopic pressure for reactive oxygen species generation to further kill cancer cells. The new function for old materials may open up the in-depth exploration of MoS₂-based functional biomaterials in the future clinical application of imaging-guided photothermal and piezocatalytic synergetic treatment.

Nanomaterials as multimodal photothermal agents (PTAs) against 'Superbugs'

Superbugs, also known as multidrug-resistant bacteria, have become a lethal and persistent threat due to their unresponsiveness toward conventional antibiotics. The main reason for this is that superbugs can rapidly mutate and restrict any foreign drug/molecule in their vicinity. Herein, nanomaterial-mediated therapies have set their path and shown burgeoning efficiency toward the ablation of superbugs. Notably, treatment modalities like photothermal therapy (PTT) have shown prominence in killing multidrug-resistant bacteria with their ability to generate local heat shock-mediated hyperthermia in such species. However, photothermal treatment has some serious limitations, such as high cost, complexity, and even toxicity to some extent. Hence, it is important to resolve such shortcomings of PTTs as they provide substantial tissue penetration. This is why multimodal PTTs have emerged and taken over this domain of research for the past few years. In this work, we have summarized and critically reviewed such exceptional works of recent times and provided a perspective to enhance their efficiencies. Profoundly, we discuss the design rationales of some novel photothermal agents (PTAs) and shed light on their mechanisms. Finally, challenges for PTT-derived multimodal therapy are presented, and capable synergistic bactericidal prospects are anticipated.

Design of One-for-All Near-Infrared Aggregation-Induced Emission Nanoaggregates for Boosting Theranostic Efficacy

Fluorescence-guided phototherapy, including photodynamic and photothermal therapy, is considered an emerging noninvasive strategy for cancer treatments. Organic molecules are promising theranostic agents because of their facile construction, simple modification, and good biocompatibility. Organic systems that integrated multifunctionalities in a single component and achieved high efficiency in both imaging and therapies are rarely reported as the inherently competitive energy relaxation pathways are hard to modulate, and fluorescence quenching occurs upon molecular aggregation. Herein, a versatile theranostic platform with near-infrared emission, high fluorescence quantum yield, robust reactive oxygen species production, and excellent photothermal conversion efficiency was developed based on an aggregation-induced emission luminogen, namely, TPA-TBT. In vivo studies revealed that the TPA-TBT nanoaggregates exhibit outstanding photodynamic and photothermal therapy efficacy to ablate tumors inoculated in a mouse model. This work offers a design strategy to develop one-for-all cancer theranostic agents by modulating and utilizing the relaxation energy of excitons in full.

Machine Learning Predicting Optimal Preparation of Silica-Coated Gold Nanorods for Photothermal Tumor Ablation

Gold nanorods (GNRs) coated with silica shells are excellent photothermal agents with high surface functionality and biocompatibility. Understanding the correlation of the coating process with both structure and property of silica-coated GNRs is crucial to their optimizing preparation and performance, as well as tailoring potential applications. Herein, we report a machine learning (ML) prediction of coating silica on GNR with various preparation parameters. A total of 306 sets of silica-coated GNRs altogether were prepared via a sol-gel method, and their structures were characterized to extract a dataset available for eight ML algorithms. Among these algorithms, the eXtreme gradient boosting (XGboost) classification model affords the highest prediction accuracy of over 91%. The derived feature importance scores and relevant decision trees are employed to address the optimal process to prepare well-structured silica-coated GNRs. The high-throughput predictions have been adopted to identify optimal process parameters for the successful preparation of dumbbell-structured silica-coated GNRs, which possess a superior performance to a conventional cylindrical core-shell counterpart. The dumbbell silica-coated GNRs demonstrate an efficient enhanced photothermal performance in vivo and in vitro, validated by both experiments and time domain finite difference calculations. This study epitomizes the potential of ML algorithms combined with experiments in predicting, optimizing, and accelerating the preparation of core-shell inorganic materials and can be extended to other nanomaterial research.

TGF-β blocking combined with photothermal therapy promote tumor targeted migration and long-term antitumor activity of CAR-T cells

TGF-β is widely existed in tumor microenvironment, taking part in tumorigenesis process including angiogenesis, cancer associated fibroblast (CAF) proliferation, and immunosuppression. It inhibited the activation, proliferation, migration and differentiation of T cells, in which way caused a limited therapeutic effects of chimeric antigen receptor T (CAR-T) towards solid tumor such as lymphoma. To targeted block TGF-β at tumor site, we take advantages of nano-techniques to deliver TGF-β inhibitors LY2157299 (LY) towards the tumor sites, in order to help achieve a improved and long-term functions of CAR-T towards lymphoma. Based on amphipathic hydroxyethyl starch-polycaprolactone (HES-PCL), LY and photosensitizer indocyanine green (ICG) were co-loaded in HES-PCL to achieve LY/ICG@HES-PCL nanoparticle. The enhanced function of CAR-T benefited from LY/ICG@HES-PCL were verified through lymphoma Raji cells in vitro and Nod scid gamma mice engrafted with the Raji cells in vivo. LY was targeted transported to tumor site and accelerated release by mild ICG photothermal. Chemokines CXCL9/10/11 ​at the tumor site relevant to CAR-T migration and chemokines receptor CXCR3 of CAR-T could be up-regulated by LY, thus facilitated the enhanced accumulation of CAR-T at lymphoma site. T effector memory cells differentiation could also be accelerated by LY/ICG@HES-PCL. Combined therapy of LY/ICG@HES-PCL and CAR-T achieved 2.4 times higher antitumor activity and 2.7 times higher relapse inhibiting rates than CAR-T alone within 15 days and 11 days, respectively. The results suggested that LY/ICG@HES-PCL facilitated the enhanced therapeutic index of CAR-T cells towards lymphoma simply and safely, it may be further potentiated applied for other solid tumors.

Titanium-Based Nanoarchitectures for Sonodynamic Therapy-Involved Multimodal Treatments

Sonodynamic therapy (SDT) has considerably revolutionized the healthcare sector as a viable noninvasive therapeutic procedure. It employs a combination of low-intensity ultrasound and chemical entities, known as a sonosensitizer, to produce cytotoxic reactive oxygen species (ROS) for cancer and antimicrobial therapies. With nanotechnology, several unique nanoplatforms are introduced as a sonosensitizers, including, titanium-based nanomaterials, thanks to their high biocompatibility, catalytic efficiency, and customizable physicochemical features. Additionally, developing titanium-based sonosensitizers facilitates the integration of SDT with other treatment modalities (for example, chemotherapy, chemodynamic therapy, photodynamic therapy, photothermal therapy, and immunotherapy), hence increasing overall therapeutic results. This review summarizes the most recent developments in cancer therapy and tissue engineering using titanium nanoplatforms mediated SDT. The synthesis strategies and biosafety aspects of Titanium-based nanoplatforms for SDT are also discussed. Finally, various challenges and prospects for its further development and potential clinical translation are highlighted.

Polydopamine nanomotors loaded indocyanine green and ferric ion for photothermal and photodynamic synergistic therapy of tumor

The limited penetration depth of nanodrugs in the tumor and the severe hypoxia inside the tumor significantly reduce the efficacy of photothermal-photodynamic synergistic therapy (PTT-PDT). Here, we synthesized a methoxypolyethylene glycol amine (mPEG-NH₂)-modified walnut-shaped polydopamine nanomotor (PDA-PEG) driven by near-infrared light (NIR). At the same time, it also loaded the photosensitizer indocyanine green (ICG) via electrostatic/hydrophobicinteractions and chelated with ferric ion (Fe³⁺). Under the irradiation of NIR, the asymmetry of PDA-PEG morphology led to the asymmetry of local photothermal effects and the formation of thermal gradient, which can make the nanomotor move autonomously. This ability of autonomous movement was proved to be used to improve the permeability of the nanomotor in three-dimensional (3D) tumor sphere. Fe³⁺ can catalyze endogenous hydrogen peroxide to produce oxygen, so as to overcome the hypoxia of tumor microenvironment and thereby generate more singlet oxygen to kill tumor cells. Animal experiments in vivo confirmed that the nanomotors had a good PTT-PDT synergistic treatment effect. The introduction of nanomotor technology has brought new ideas for cancer optical therapy.

Nano-biotechnology in tumour and cancerous disease: A perspective review

In recent years, drug manufacturers and researchers have begun to consider the nanobiotechnology approach to improve the drug delivery system for tumour and cancer diseases. In this article, we review current strategies to improve tumour and cancer drug delivery, which mainly focuses on sustaining biocompatibility, biodistribution, and active targeting. The conventional therapy using cornerstone drugs such as fludarabine, cisplatin etoposide, and paclitaxel has its own challenges especially not being able to discriminate between tumour versus normal cells which eventually led to toxicity and side effects in the patients. In contrast to the conventional approach, nanoparticle-based drug delivery provides target-specific delivery and controlled release of the drug, which provides a better therapeutic window for treatment options by focusing on the eradication of diseased cells via active targeting and sparing normal cells via passive targeting. Additionally, treatment of tumours associated with the brain is hampered by the impermeability of the blood-brain barriers to the drugs, which eventually led to poor survival in the patients. Nanoparticle-based therapy offers superior delivery of drugs to the target by breaching the blood-brain barriers. Herein, we provide an overview of the properties of nanoparticles that are crucial for nanotechnology applications. We address the potential future applications of nanobiotechnology targeting specific or desired areas. In particular, the use of nanomaterials, biostructures, and drug delivery methods for the targeted treatment of tumours and cancer are explored.

Reduction-Hypersensitive Podophyllotoxin Prodrug Self-Assembled Nanoparticles for Cancer Treatment

Podophyllotoxin (PPT) has shown strong antitumor effects on various types of cancers. However, the non-specific toxicity and poor solubility severely limits its clinical transformation. In order to overcome the adverse properties of PPT and explore its clinical potential, three novel PTT−fluorene methanol prodrugs linked by different lengths of disulfide bonds were designed and synthesized. Interestingly, the lengths of the disulfide bond affected the drug release, cytotoxicity, pharmacokinetic characteristics, in vivo biodistribution and antitumor efficacy of prodrug NPs. To be more specific, all three PPT prodrugs could self-assemble into uniform nanoparticles (NPs) with high drug loading (>40%) via the one-step nano precipitation method, which not only avoids the use of surfactants and cosurfactants, but also reduces the systemic toxicity of PPT and increases the tolerated dose. Among the three prodrug NPs, FAP NPs containing α-disulfide bond showed the most sensitive tumor-specific response and fastest drug release rate, thus demonstrating the strongest in vitro cytotoxicity. In addition, three prodrug NPs showed prolonged blood circulation and higher tumor accumulation. Finally, FAP NPs demonstrated the strongest in vivo antitumor activity. Our work will advance the pace of podophyllotoxin towards clinical cancer treatment.

Metal selenide nanomaterials for biomedical applications

Metal selenide nanomaterials have received enormous attention as they possess diverse compositions, microstructures, and properties. The combination of selenium with various metallic elements gives the metal selenide nanomaterials distinctive optoelectronic and magnetic properties, such as strong near-infrared absorption, excellent imaging properties, good stability, and long in vivo circulation. This makes metal selenide nanomaterials advantageous and promising for biomedical applications. This paper summarizes the research progress in the last five years in the controlled synthesis of metal selenide nanomaterials in different dimensions and with different compositions and structures. Then we discuss how surface modification and functionalization strategies are well-suited for biomedical fields, including tumor therapy, biosensing, and antibacterial biological applications. The future trends and issues of metal selenide nanomaterials in the biomedical field are also discussed.

Self-Assembled Aza-BODIPY and Iron(III) Nanoparticles for Photothermal-Enhanced Chemodynamic Therapy in the NIR-II Window

Despite its promising potential in cancer treatment, synergistic photothermal/chemodynamic therapy remains underdeveloped with regard to the utilization of metal-organic materials under second near-infrared (NIR-II) laser excitation. Herein, we report a three-dimensional network constructed via the metal coordination between catechol-functionalized aza-boron dipyrromethenes and iron ions (ABFe), which was further encapsulated by F127 to obtain ABFe nanoparticles (NPs) for combined photothermal/chemodynamic therapy. ABFe NPs exhibited intense absorption in the NIR-II range and negligible fluorescence. Upon 1064 nm laser irradiation, ABFe NPs showed high photothermal conversion efficiency (PCE = 55.0%) and excellent photothermal stability. The results of electron spin resonance spectra and o-phenylenediamine chromaticity spectrophotometry proved that ABFe NPs were capable of generating harmful reactive oxygen species from hydrogen peroxide for chemodynamic therapy, which was promoted by photothermal performance. Notably, in vitro and in vivo experiments demonstrated the great potential of ABFe NPs in photoacoustic imaging and photothermal-enhanced chemodynamic therapy under NIR-II laser irradiation. Therefore, the current work presents a prospective NIR-II excitation therapeutic nanomedicine for combination therapy, offering a novel strategy for simultaneously achieving extended NIR absorption of aza-BODIPY and enhanced chemodynamic therapy with metal-organic materials.

Recent advances in lanthanide-doped up-conversion probes for theranostics

Up-conversion (or anti-Stokes) luminescence refers to the phenomenon whereby materials emit high energy, short-wavelength light upon excitation at longer wavelengths. Lanthanide-doped up-conversion nanoparticles (Ln-UCNPs) are widely used in biomedicine due to their excellent physical and chemical properties such as high penetration depth, low damage threshold and light conversion ability. Here, the latest developments in the synthesis and application of Ln-UCNPs are reviewed. First, methods used to synthesize Ln-UCNPs are introduced, and four strategies for enhancing up-conversion luminescence are analyzed, followed by an overview of the applications in phototherapy, bioimaging and biosensing. Finally, the challenges and future prospects of Ln-UCNPs are summarized.

Insight on nano drug delivery systems with targeted therapy in treatment of oral cancer

Oral cancer is a type of cancer that develops in the mouth and is one of the deadliest malignancies in the world. Currently surgical, radiation therapy, and chemotherapy are most common treatments. Better treatment and early detection strategies are required. Chemotherapeutic drugs fail frequently due to toxicity and poor tumor targeting. There are high chances of failure of chemotherapeutic drugs due to toxicity. Active, passive, and immunity-targeting techniques are devised for tumor-specific activity. Nanotechnology-based drug delivery systems are the best available solution and important for precise targeting. Nanoparticles, liposomes, exosomes, and cyclodextrins are nano-based carriers for drug delivery. Nanotechnology is being used to develop new techniques such as intratumoral injections, microbubble mediated ultrasonic therapy, phototherapies, and site-specific delivery. This systematic review delves into the details of such targeted and nano-based drug delivery systems in order to improve patient health and survival rates in oral cancer.

Development of Wireless Power-Transmission-Based Photodynamic Therapy for the Induction of Cell Death in Cancer Cells by Cyclometalated Iridium(III) Complexes

Photodynamic therapy (PDT), a noninvasive method for cancer therapy, involves the generation of reactive oxygen species (ROS) by the photochemical excitation of photosensitizers (PSs) to induce cell death in cancer cells. A variety of PS including porphyrin derivatives and metal complexes such as iridium (Ir) complexes have been reported. In clinical trials, red-near infrared (NIR) light (650-900 nm) is preferred for the excitation of PSs due to its deeper penetration into tissues compared with visible light (400-500 nm). To overcome this limitation, we established a PDT system that uses cyclometalated iridium(III) (Ir(III)) complexes that are excited with blue light in the wireless power transmission (WPT) system. To achieve this, we developed a light-emitting diode (LED) light device equipped with a receiver coil that receives electricity from the transmitter coil through magnetic resonance coupling. The LEDs in the receiving device use blue light (470 nm) to irradiate a given Ir(III) complex and excite triplet oxygen (³O₂) to singlet oxygen (¹O₂) which induces cell death in HeLa S3 cells (human cervical carcinoma cells). The results obtained in this study suggest that WPT-based PDT represents a potentially new method for the treatment of tumors by a non-battery LED, which are otherwise difficult to treat by previous PDT systems.

Functionalized biomimetic nanoparticles combining programmed death-1/programmed death-ligand 1 blockade with photothermal ablation for enhanced colorectal cancer immunotherapy

Immune checkpoint blockade therapy targeting programmed death-1 (PD-1) or its major ligand programmed death-ligand 1 (PD-L1) has achieved remarkable success in the treatment of several tumors, including colorectal cancer. However, the efficacy of PD-1/PD-L1 inhibitors is limited in some colorectal cancers within the immunosuppressive tumor microenvironment (such as when there is a lack of immune cell infiltration). Herein, anti-PD-L1 functionalized biomimetic polydopamine-modified gold nanostar nanoparticles (PDA/GNS@aPD-L1 NPs) were developed for synergistic anti-tumor treatment by combining PD-1/PD-L1 blockade with photothermal ablation. PDA/GNS@aPD-L1 NPs were prepared by encapsulating photothermal nanoparticles (polydopamine-modified gold nanostar, PDA-GNS) with cell membrane isolated from anti-PD-L1 single-chain variable fragment (scFv) over-expressing cells. In addition to disrupting PD-1/PD-L1 immunosuppressive signals, the anti-PD-L1 scFv on the membrane of PDA/GNS@aPD-L1 NPs was conducive to the accumulation of PDA-GNS at tumor sites. Importantly, the tumor photothermal ablation induced by PDA-GNS could reverse the immunosuppressive tumor microenvironment, thereby further improving the efficiency of PD-1/PD-L1 blockade therapy. In this study, the synthetized PDA/GNS@aPD-L1 NPs exhibited good biocompatibility, efficient photothermal conversion ability, and enhanced tumor-targeting ability. In vivo studies revealed that a PDA/GNS@aPD-L1 NP-based therapeutic strategy significantly inhibited tumor growth, and prolonged overall survival by further promoting the maturation of dendritic cells (DCs), increasing the infiltration of CD8⁺T cells, and decreasing the number of immunosuppressive cells (such as regulatory T cells and myeloid-derived suppressive cells). Collectively, the developed PDA/GNS@aPD-L1 NP-based therapeutic strategy combines PD-1/PD-L1 blockade with photothermal ablation, which could remodel the tumor microenvironment for effective clinical colorectal cancer therapy. STATEMENT OF SIGNIFICANCE: Immunosuppressive tumor microenvironment is the main challenge facing programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) blockade therapy. By encapsulating photothermal nanoparticles (polydopamine-modified gold nanostar, PDA-GNS) with cell membrane over-expressing anti-PD-L1 single-chain variable fragment, we constructed anti-PD-L1 functionalized biomimetic nanoparticles (PDA/GNS@aPD-L1 NPs). By specific binding to the PD-L1 present on tumor cells, PDA/GNS@aPD-L1 NPs could disrupt PD-1/PD-L1 immunosuppression signaling, and effectively deliver PDA-GNS targeting to tumor sites. Additionally, PDA-GNS-mediated local photothermal ablation of tumors promoted the release of tumor-associated antigens and thus activated anti-tumor immune responses. Meanwhile, hyperthermia facilitates immune cell infiltration by increasing tumor vascular permeability. Therefore, PDA/GNS@aPD-L1 NPs could sensitize tumors to PD-1/PD-L1 blockade therapy by remodeling the immunosuppressive tumor microenvironment, which provides a new strategy for tumor treatment.

Two-Dimensional FePS3 Nanosheets as an Integrative Sonosensitizer/Nanocatalyst for Efficient Nanodynamic Tumor Therapy

As the emerging modalities for tumor therapy, sonodynamic therapy (SDT) and chemodynamic therapy (CDT) can generate reactive oxygen species (ROS), typically inducing tumor cell apoptosis. However, the construction of more efficient sonosensitizers integrated with excellent Fenton/Fenton-like catalytic activity to improve the synergistic therapeutic effect of SDT and CDT is still highly challenging. In this study, 2D semiconductor FePS₃ nanosheets (NSs), as one of the metal phosphorus trichalcogenides for both sonosensitizer and Fenton catalyst, are successfully synthesized via an ultrasonic-assisted liquid phase exfoliation method from bulk FePS₃ and further modified with lipoic acid-polyethylene glycol (LA-PEG) to obtain FePS₃ -PEG NSs with desirable biocompatibility. The in vitro and in vivo results demonstrate that the engineered FePS₃ -PEG NSs induce the combinatorial SDT/CDT effect attributing to the enhanced ROS generation and significant glutathione depletion, which can conduct highly efficient and safe tumor inhibition and prolong the life span of tumor-bearing mice. This work provides the paradigm of semiconductor FePS₃ NSs as the integrative sonosensitizer/Fenton nanocatalyst for dual nanodynamic tumor therapy, paving the new way for exploring other 2D metal phosphorus trichalcogenides in biomedicine.

Multicompartment Nanoparticles by Crystallization-Driven Self-Assembly of Star Polymers: Combining High Stability and Loading Capacity

Herein novel multicompartment nanoparticles (MCNs) that combine high stability and cargo loading capacity are developed. The MCNs are fabricated by crystallization-driven self-assembly (CDSA) of a tailor-made 21 arm star polymer, poly(L-lactide)[poly(tert-butyl acrylate)-block-poly(ethylene glycol)]₂₀ [PLLA(PtBA-b-PEG)₂₀ ]. Platelet-like or spherical MCNs containing a crystalline PLLA core and hydrophobic PtBA subdomains are formed and stabilized by PEG. Hydrophobic cargos, such as Nile Red and chemotherapeutic drug doxorubicin, can be successfully encapsulated into the collapsed PtBA subdomains with loading capacity two orders of magnitude higher than traditional CDSA nanoparticles. Depolarized fluorescence measurements of the Nile Red loaded MCNs suggest that the free volume of the hydrophobic chains in the nanoparticles may be the key for regulating their drug loading capacity. In vitro study of the MCNs suggests excellent cytocompatibility of the blank nanoparticles as well as a dose-dependent cellular uptake and cytotoxicity of the drug-loaded MCNs.

Pt(II) metallacycles encapsulated by ferritin enable precise cancer combination chemo-photodynamic therapy

Different from common anti-tumor drugs, organoplatinum(II) metallacycles can integrate imaging and other therapeutic capabilities by incorporating corresponding functional donor ligands to enable potential applications in biomedicine. However, most of the emerging therapeutic agents not only show poor solubility and selectivity but also have serious side effects and unsatisfactory efficacy and encounter the tendency to develop drug resistance due to their single treatment model. Herein, an organoplatinum(II) metallacycle (PtM) was designed and synthesized using coordination-driven self-assembly via the combination of a metallic chemotherapy precursor and a reactive oxygen species generating organic precursor. The hydrophobic PtM molecules were encapsulated in the cavity of human heavy chain ferritin (HFn) during the reassembly of HFn to prepare the active targeting nanoagent HFn-PtM for use in chemo-photodynamic combination therapy. The HFn-PtM nanoagents exhibited excellent stability in buffer (pH from 5 to 7.2), alleviating the concern of drug leakage during circulation. A cellular uptake assay indicated that HFn-PtM could efficiently enter specific cells that overexpress the transferrin receptor 1. In vitro and in vivo anti-tumor investigations revealed that HFn-PtM exhibited excellent anti-tumor efficiency with negligible systemic toxicity. This work provides a strategy for the easy construction of multifunctional organoplatinum-based tumor-targeted drugs.

Novel albumin-binding photodynamic agent EB-Ppa for targeted fluorescent imaging guided tumour photodynamic therapy

The targeted and novel albumin-binding strategy has been attractive in the field of cancer therapy. Herein, we have developed an organic small molecule-based photosensitizer, Evans Blue-Pyropheophorbide-alpha (EB-Ppa), to treat solid tumors with extremely high photodynamic therapeutic efficiency, which is stable in serum-containing aqueous media and can effectively accumulate in the tumor site due to the enhanced permeability and retention (EPR) effect. Particularly, after the photodynamic therapeutic treatment with EB-Ppa, all breast tumors (4T1 cell line) xenografted in nude mice shrink fast due to the singlet oxygen generated by EB-Ppa with laser irradiation. Furthermore, EB-Ppa shows negligible toxicity in major organs. These results demonstrate that EB-Ppa presents the great potential of photodynamic therapy for efficient tumor treatment.

Smart Chemical Oxidative Polymerization Strategy To Construct Au@PPy Core-Shell Nanoparticles for Cancer Diagnosis and Imaging-Guided Photothermal Therapy

Imaging-guided photothermal therapy (PTT) in a single nanoscale platform has aroused extensive research interest in precision medicine, yet only a few methods have gained wide acceptance. Thus, it remained an urgent need to facilely develop biocompatible and green probes with excellent theranostic capacity for superior biomedical applications. In this study, a smart chemical oxidative polymerization strategy was successfully developed for the synthesis of Au@PPy core-shell nanoparticles with polyvinyl alcohol (PVA) as the hydrophile. In the reaction, the reactant tetrachloroauric acid (HAuCl₄) was reduced by pyrrole to fabricate a gold (Au) core, and pyrrole was oxidized to deposit around the Au core to form a polypyrrole (PPy) shell. The as-synthesized Au@PPy nanoparticles showed a regular core-shell morphology and good colloidal stability. Relying on the high X-ray attenuation of Au and strong near-infrared (NIR) absorbance of PPy and Au, Au@PPy nanoparticles exhibited excellent performance in blood pool/tumor imaging and PTT treatment by a series of in vivo experiments, in which tumor could be precisely positioned and thoroughly eradicated. Hence, the facile chemical oxidative polymerization strategy for constructing monodisperse Au@PPy core-shell nanoparticles with potential for cancer diagnosis and imaging-guided photothermal therapy shed light on an innovative design concept for the facile fabrication of biomedical materials.

De Novo Design of Reversibly pH-Switchable NIR-II Aggregation-Induced Emission Luminogens for Efficient Phototheranostics of Patient-Derived Tumor Xenografts

Phototheranostics has received sustained attention due to its great potential in revolutionizing conventional strategies of cancer treatment. However, trapped by the complexity, poor reproducibility, insufficient phototheranostic outputs, and inevitable damage to normal tissue of most multicomponent phototheranostic systems, its clinical translation has been severely hindered. Therefore, the exploration of "one for all" smart phototheranostic agents with versatile functionalities remains an appealing yet enormously challenging task. Herein, a reversibly pH-switchable and near-infrared second photosensitizer featuring aggregation-induced emission was tactfully designed by molecular engineering for precise tumor-targeting fluorescence imaging-guided phototherapy. Thanks to the strong intramolecular charge transfer, enhanced highly efficient intersystem crossing, and sufficient intramolecular motion, the developed agent DTTVBI was endowed with boosted type-I superoxide anion radical generation and excellent photothermal performance under 808 nm laser irradiation. More importantly, DTTVBI nanoparticles with high biocompatibility exhibit remarkably enhanced type-I photodynamic/photothermal therapy in the tumor region, thus offering significant antitumor effects both in vitro and in the patient-derived tumor xenograft model of colon cancer. This work sheds new light on the development of superior versatile phototheranostics for cancer therapy.

Chirality-Dependent Tumor Phototherapy Using Amino Acid-Engineered Chiral Phosphorene

Phosphorene, also known as black phosphorus nanosheet (BPNS), has been investigated as a nanoagent for tumor therapy. However, promoting its intracellular accumulation while preventing the cytoplasmic decomposition remains challenging. Herein, for the first time, we propose a chiral BPNS designed through surface engineering based on amino acids with high biocompatibility and an abundant source for application in chirality-dependent tumor phototherapy based on its intracellular metabolism. The advantage of using cysteine (Cys) over other amino acids was that its d, l, or dl-form could efficiently work as the chirality inducer to modify the BPNS through electrostatic interaction and prevent alterations in the intrinsic properties of the BPNS. In particular, d-Cys-BPNS displayed an approximately threefold cytotoxic effect on tumor cells compared with l-Cys-BPNS, demonstrating a chirality-dependent therapy behavior. d-Cys-BPNS not only promoted high intracellular content but also showed resistance to cytoplasmic decomposition. Cys-engineered BPNS also demonstrated chirality-dependent phototherapy effects on tumor-bearing mice, in proximity to the results in vitro. Chiral engineering is expected to open new avenues that could promote the use of BPNS in tumor phototherapy and boost chiral nanomedicine.

Phototheranostic Agents Based on Nonionic Heptamethine Cyanine for Realizing Synergistic Cancer Phototherapy

Asymmetrical heptamethine cyanine with near-infrared (NIR) absorption is used for photothermal therapy (PTT) of cancer. Aiming to overcome the drawbacks caused by the high temperature of PTT, the development of asymmetrical heptamethine cyanine with photothermal and photodynamic properties is still an attractive strategy. Different from the traditional method of the heavy atom effect, in this work, the carboxyl or sulfonic groups are introduced into the indole ring or branch chain of asymmetrical heptamethine cyanine to afford a series of new phototherapy agents. After being encapsulated by DSPE-PEG₂₀₀₀ , BSS-Et NPs exhibit robust photostability, efficient reactive oxygen species generation (49%), and excellent photothermal conversion efficiency of about 37.6% under 808 nm laser irradiation. BSS-Et NPs possess passive tumor-targeting properties in vivo to not only visualize the tumor by NIR fluorescence imaging but also eliminate the tumor without any recurrence by photodynamic therapy and PTT synergistic therapy under laser irradiation. In addition, benefitting from the characteristics of organic small molecules, they can be metabolized quickly through the liver without inducing toxicity in the whole body. In general, this study provides a new direction for the development of multifunctional phototherapy agents for cancer treatment.

Advanced materials and technologies for oral diseases

Oral disease, as a class of diseases with very high morbidity, brings great physical and mental damage to people worldwide. The increasing burden and strain on individuals and society make oral diseases an urgent global health problem. Since the treatment of almost all oral diseases relies on materials, the rapid development of advanced materials and technologies has also promoted innovations in the treatment methods and strategies of oral diseases. In this review, we systematically summarized the application strategies in advanced materials and technologies for oral diseases according to the etiology of the diseases and the comparison of new and old materials. Finally, the challenges and directions of future development for advanced materials and technologies in the treatment of oral diseases were refined. This review will guide the fundamental research and clinical translation of oral diseases for practitioners of oral medicine.

Terpyridine-Grafted Nitrogen-Terminal Endowing Cyanine with Metal-Ion-Regulated Photophysical Properties for Cancer Theranostics

Heptamethine cyanines (Cy7) are one of the most important dyes in bioimaging and phototherapy, but they often suffer from poor photostability or limited photothermal conversion efficiency. Here, a facile molecular engineering approach to regulating the photophysical properties of Cy7 by metal ions is demonstrated. By innovatively modifying the nitrogen with functional groups, a novel terpyridine-grafted nitrogen-terminated Cy7 scaffold (denoted as CydtPy) was synthesized and exhibited tunable photophysical properties when chelating with various metal ions (Mn²⁺, Fe²⁺, etc.). In comparison with metal-ion-free PEGylated CydtPy (LET-11), Mn²⁺-chelated LET-11 (namely, LET-11-Mn) exhibited the increased fluorescence emission intensity, and Fe²⁺-chelated LET-11 (namely, LET-11-Fe) showed the enhanced photostability with ~2-fold increase in photothermal conversion efficiency. By simply switching the chelated metal ion species, LET-11-Mn or LET-11-Fe could be used for near-infrared fluorescence imaging, magnetic resonance imaging, or photoacoustic imaging. Furthermore, LET-11-Fe displayed superior synergistic efficacy of photothermal therapy and chemodynamic therapy both in vitro and in vivo. This work not only provides a new strategy for regulating the photophysical properties of cyanine dyes but also establishes a versatile nanoplatform for cancer theranostics.

Fluorination Enhances NIR-II Emission and Photothermal Conversion Efficiency of Phototheranostic Agents for Imaging-Guided Cancer Therapy

Phototheranostics with second near-infrared (NIR-II) imaging and photothermal effect have become a burgeoning biotechnology for tumor diagnosis and precise treatment. As important parameters of phototheranostic agents (PTAs), fluorescence quantum yield (QY) and photothermal conversion efficiency (PCE) are usually considered as a pair of contradictions that is difficult to be simultaneously enhanced. Herein, a fluorination strategy for designing A-D-A type PTAs with synchronously improved QY and PCE is proposed. Experimental results show that the molar extinction coefficient (ε), NIR-II QY, and PCE of all fluorinated PTAs nanoparticles (NPs) are definitely improved compared with the chlorinated counterparts. Theoretical calculation results demonstrate that fluorination can maximize the electrostatic potential difference by virtue of the high electronegativity of fluorine, which may increase intra/intermolecular D-A interactions, tighten molecule packing, and further promote the increase of ε, ultimately leading to simultaneously enhanced QY and PCE. In these PTA NPs, FY6-NPs display NIR-II emission extended to 1400 nm with the highest NIR-II QY (4.2%) and PCE (80%). These features make FY6-NPs perform well in high-resolution imaging of vasculature and NIR-II imaging-guided photothermal therapy (PTT) of tumors. This study develops a valuable guideline for constructing NIR-II organic PTAs with high performance.

Spatiotemporally Controlled Formation and Rotation of Magnetic Nanochains In Vivo for Precise Mechanotherapy of Tumors

Systemic cancer therapy is always accompanied with toxicity to normal tissue, which has prompted concerted efforts to develop precise treatment strategies. Herein, we firstly develop an approach that enables spatiotemporally controlled formation and rotation of magnetic nanochains in vivo, allowing for precise mechanotherapy of tumor. The nanochain comprised nanocomposites of pheophorbide-A (PP) modified iron oxide nanoparticle (IONP) and lanthanide-doped down-conversion NP (DCNP). In a permanent magnetic field, the nanocomposites would be aligned to form nanochain. Next, MnO₂ NPs were subsequently administered to accumulate in tumor as suppliers of Mn²⁺ , which coordinates with PP to immobilize the nanochain. In a rotating magnetic field, the nanochain would rapidly rotate, leading to apoptosis/necrosis of tumor cell. The nanochain showed high T₂ -MR and NIR-II fluorescence imaging signals, which facilitated guided therapy. The strategy has great potential in practical applications.

Cancer nanomedicine in preoperative therapeutics: Nanotechnology-enabled neoadjuvant chemotherapy, radiotherapy, immunotherapy, and phototherapy

Surgical resection remains a mainstay in the treatment of malignant solid tumors. However, the use of neoadjuvant treatments, including chemotherapy, radiotherapy, phototherapy, and immunotherapy, either alone or in combination, as a preoperative intervention regimen, have attracted increasing attention in the last decade. Early randomized, controlled trials in some tumor settings have not shown a significant difference between the survival rates in long-term neoadjuvant therapy and adjuvant therapy. However, this has not hampered the increasing use of neoadjuvant treatments in clinical practice, due to its evident downstaging of primary tumors to delineate the surgical margin, tailoring systemic therapy response as a clinical tool to optimize subsequent therapeutic regimens, and decreasing the need for surgery, with its potential for increased morbidity. The recent expansion of nanotechnology-based nanomedicine and related medical technologies provides a new approach to address the current challenges of neoadjuvant therapy for preoperative therapeutics. This review not only summarizes how nanomedicine plays an important role in a range of neoadjuvant therapeutic modalities, but also highlights the potential use of nanomedicine as neoadjuvant therapy in preclinical and clinic settings for tumor management.

In-situ bio-assembled specific Au NCs-Aptamer-Pyro conjugates nanoprobe for tumor imaging and mitochondria-targeted photodynamic therapy

Mitochondrion has emerged as a promising drug target for photodynamic therapy (PDT), due to its significant role in supporting life activities and being reactive oxygen species (ROS)-sensitive. Herein, we establish a new strategy that in-situ bio-synthesized Au NCs combine with mitochondria-targeted aptamer-Pyro conjugates (ApPCs) for specific tumor imaging and PDT. The prepared ApPCs can serve as template for the in-situ bio-synthesis of Au NCs, thereby facilitating the generation of Au NCs-ApPCs assemblies in unique tumor microenvironment. Compared with highly negatively charged ApPCs, bio-synthesized nanoscale Au NCs-ApPCs assemblies are conducive to cell uptake, which consequently benefits the delivery of ApPCs. After dissociated from Au NCs-ApPCs, internalized ApPCs can selectively accumulate in mitochondria and generate excess ROS to disrupt the mitochondrial membrane upon irradiation, thus inducing efficient cell killing. In vitro assays demonstrated that the fluorescent Au NCs-ApPCs assemblies could be specifically produced in cancerous cells, indicating the specific tumor imaging ability, while intracellular ApPCs co-localized well with mitochondria. CCK-8 results revealed over 80% cell death after PDT. In vivo study showed that fluorescent Au NCs-ApPCs assemblies were exclusively generated in tumor and achieved long-term retention; tumor growth was significantly inhibited after 15-day PDT treatment. All these evidences suggest that in-situ bio-synthesized Au NCs-ApPCs assembly is a potent mitochondria-targeted nanoprobe to boost the PDT efficacy of cancers.