Improved cancer phototheranostic efficacy of hydrophobic IR780 via parenteral route by association with tetrahedral nanostructured DNA

Nitroreductase-Responsive Fluorescent "Off-On" Photosensitizer for Hypoxic Tumor Imaging and Dual-Modal Therapy

Photothermal therapy synergized with photodynamic therapy for the treatment of tumors has emerged as a promising strategy. However, designing photosensitizers with both high photothermal efficiency and high photodynamic performance remains challenging. In contrast, the strategy of rationalizing the design of photosensitizers using the physiological properties of tumors to improve the photon utilization of photosensitizers during phototherapy is more advantageous than the approach of endowing a single photosensitizer with complex functions. Herein, we propose a molecular design (CyNP) to convert from photothermal therapy to photodynamic synergistic photothermal therapy based on the prevalent properties of hypoxic tumors. In the normoxic region of tumors, the deactivation pathway of CyNP excited state is mainly the conversion of photon energy to thermal energy; in the hypoxic region of tumors, CyNP is reduced to CyNH by nitroreductase, and the deactivation pathway mainly includes radiation leap, energy transfer between CyNP and oxygen, and conversion of photons energy to heat energy. This strategy enables real-time fluorescence detection of hypoxic tumors, and it also provides dual-mode treatment for photothermal and photodynamic therapy of tumors, achieving good therapeutic effects in vivo tumor treatment. Our study achieves more efficient tumor photoablation and provides a reference for the design ideas of smart photosensitizers.

Supramolecular dye nanoassemblies for advanced diagnostics and therapies

Dyes have conventionally been used in medicine for staining cells, tissues, and organelles. Since these compounds are also known as photosensitizers (PSs) which exhibit photoresponsivity upon photon illumination, there is a high desire towards formulating these molecules into nanoparticles (NPs) to achieve improved delivery efficiency and enhanced stability for novel imaging and therapeutic applications. Furthermore, it has been shown that some of the photophysical properties of these molecules can be altered upon NP formation thereby playing a major role in the outcome of their application. In this review, we primarily focus on introducing dye categories, their formulation strategies and how these strategies affect their photophysical properties in the context of photothermal and non-photothermal applications. More specifically, the most recent progress showing the potential of dye supramolecular assemblies in modalities such as photoacoustic and fluorescence imaging, photothermal and photodynamic therapies as well as their employment in photoablation as a novel modality will be outlined. Aside from their photophysical activity, we delve shortly into the emerging application of dyes as drug stabilizing agents where these molecules are used together with aggregator molecules to form stable nanoparticles.

Drug repurposing-based nanoplatform via modulating autophagy to enhance chemo-phototherapy against colorectal cancer

Multi-modal combination therapy is regarded as a promising approach to cancer treatment. Combining chemotherapy and phototherapy is an essential multi-modal combination therapy endeavor. Ivermectin (IVM) is a potent antiparasitic agent identified as having potential antitumor properties. However, the fact that it induces protective autophagy while killing tumor cells poses a challenge to its further application. IR780 iodide (IR780) is a near-infrared (NIR) dye with outstanding photothermal therapy (PTT) and photodynamic therapy (PDT) effects. However, the hydrophobicity, instability, and low tumor uptake of IR780 limit its clinical applications. Here, we have structurally modified IR780 with hydroxychloroquine, an autophagy inhibitor, to synthesize a novel compound H780. H780 and IVM can form H780-IVM nanoparticles (H-I NPs) via self-assembly. Using hyaluronic acid (HA) to modify the H-I NPs, a novel nano-delivery system HA/H780-IVM nanoparticles (HA/H-I NPs) was synthesized for chemotherapy-phototherapy of colorectal cancer (CRC). Under NIR laser irradiation, HA/H-I NPs effectively overcame the limitations of IR780 and IVM and exhibited potent cytotoxicity. In vitro and in vivo experiment results showed that HA/H-I NPs exhibited excellent anti-CRC effects. Therefore, our study provides a novel strategy for CRC treatment that could enhance chemo-phototherapy by modulating autophagy.

UV-assisted synthesis of ultra-small GO-Austar for efficient PTT therapeutic architectonic construction

Conventional Au nanomaterial synthesis typically necessitates the involvement of extensive surfactants and reducing agents, leading to a certain amount of chemical waste and biological toxicity. In this study, we innovatively employed ultra-small graphene oxide as a reducing agent and surfactant for the in situ generation of small Au nanoparticles under ultraviolet irradiation (UV) at ambient conditions. After ultra-small GO-Au seeds were successfully synthesized, we fabricated small star-like Au nanoparticles on the surface of GO, in which GO effectively prevented Austar from aggregation. To further use GO-Austar for cancer PTT therapy, through the modification of reduced human serum albumin-folic acid conjugate (rHSA-FA) and loading IR780, the final probe GO-Austar@rHSA-FA@IR780 was prepared. The prepared probe showed excellent biocompatibility and superb phototoxicity towards MGC-803 cells in vitro. In vivo, the final probe dramatically increased tumor temperature up to 58.6 °C after 5 minutes of irradiation by an 808 nm laser, significantly inhibiting tumor growth and nearly eradicating subcutaneous tumors in mice. This research provides a novel and simple method for the synthesis of GO-Au nanocomposites, showcasing significant potential in biological applications.

Sulfobetaine methacrylate-coated reduced graphene oxide-IR780 hybrid nanosystems for effective cancer photothermal-photodynamic therapy

Nanomaterials with near infrared light absorption can mediate an antitumoral photothermal-photodynamic response that is weakly affected by cancer cells' resistance mechanisms. Such nanosystems are commonly prepared by loading photosensitizers into nanomaterials displaying photothermal capacity, followed by functionalization to achieve biological compatibility. However, the translation of these multifunctional nanomaterials has been limited by the fact that many of the photosensitizers are not responsive to near infrared light. Furthermore, the reliance on poly(ethylene glycol) for functionalizing the nanomaterials is also not ideal due to some immunogenicity reports. Herein, a novel photoeffective near infrared light-responsive nanosystem for cancer photothermal-photodynamic therapy was assembled. For such, dopamine-reduced graphene oxide was, for the first time, functionalized with sulfobetaine methacrylate-brushes, and then loaded with IR780 (IR780/SB/DOPA-rGO). This hybrid system revealed a nanometric size distribution, optimal surface charge and colloidal stability. The interaction of IR780/SB/DOPA-rGO with near infrared light prompted a temperature increase (photothermal effect) and production of singlet oxygen (photodynamic effect). In in vitro studies, the IR780/SB/DOPA-rGO per se did not elicit cytotoxicity (viability > 78 %). In contrast, the combination of IR780/SB/DOPA-rGO with near infrared light decreased breast cancer cells' viability to just 21 %, at a very low nanomaterial dose, highlighting its potential for cancer photothermal-photodynamic therapy.

A photoactivatable and phenylboronic acid-functionalized nanoassembly for combating multidrug-resistant gram-negative bacteria and their biofilms

Background

Multidrug-resistant (MDR) gram-negative bacteria-related infectious diseases have caused an increase in the public health burden and mortality. Moreover, the formation of biofilms makes these bacteria difficult to control. Therefore, developing novel interventions to combat MDR gram-negative bacteria and their biofilms-related infections are urgently needed. The purpose of this study was to develop a multifunctional nanoassembly (IRNB) based on IR-780 and N, N'-di-sec-butyl-N, N'- dinitroso-1,4-phenylenediamine (BNN6) for synergistic effect on the infected wounds and subcutaneous abscesses caused by gram-negative bacteria.

Methods

The characterization and bacteria-targeting ability of IRNB were investigated. The bactericidal efficacy of IRNB against gram-negative bacteria and their biofilms was demonstrated by crystal violet staining assay, plate counting method and live/dead staining in vitro. The antibacterial efficiency of IRNB was examined on a subcutaneous abscess and cutaneous infected wound model in vivo. A cell counting kit-8 assay, Calcein/PI cytotoxicity assay, hemolysis assay and intravenous injection assay were performed to detect the biocompatibility of IRNB in vitro and in vivo.

Results

Herein, we successfully developed a multifunctional nanoassembly IRNB based on IR-780 and BNN6 for synergistic photothermal therapy (PTT), photodynamic therapy (PDT) and nitric oxide (NO) effect triggered by an 808 nm laser. This nanoassembly could accumulate specifically at the infected sites of MDR gram-negative bacteria and their biofilms via the covalent coupling effect. Upon irradiation with an 808 nm laser, IRNB was activated and produced both reactive oxygen species (ROS) and hyperthermia. The local hyperthermia could induce NO generation, which further reacted with ROS to generate ONOO-, leading to the enhancement of bactericidal efficacy. Furthermore, NO and ONOO- could disrupt the cell membrane, which converts bacteria to an extremely susceptible state and further enhances the photothermal effect. In this study, IRNB showed a superior photothermal-photodynamic-chemo (NO) synergistic therapeutic effect on the infected wounds and subcutaneous abscesses caused by gram-negative bacteria. This resulted in effective control of associated infections, relief of inflammation, promotion of re-epithelization and collagen deposition, and regulation of angiogenesis during wound healing. Moreover, IRNB exhibited excellent biocompatibility, both in vitro and in vivo.

Conclusions

The present research suggests that IRNB can be considered a promising alternative for treating infections caused by MDR gram-negative bacteria and their biofilms.

Oral pectin/oligochitosan microspheres for colon-specific controlled release of quercetin to treat inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, life quality-reducing disease with no cures available yet. To develop an effective medication suitable for long-term use is an urgent but unmet need. Quercetin (QT) is a natural dietary flavonoid with good safety and multifaceted pharmacological activities against inflammation. However, orally administrated quercetin yields unproductive outcomes for IBD treatment because of its poor solubility and extensive metabolism in the gastrointestinal tract. In this work, a colon-targeted QT delivery system (termed COS-CaP-QT) was developed, of which the pectin (PEC)/Ca²⁺ microspheres were prepared and then crosslinked by oligochitosan (COS). The drug release profile of COS-CaP-QT was pH-dependent and colon microenvironment-responsive, and COS-CaP-QT showed preferential distribution in the colon. The mechanism study showed that QT triggered the Notch pathway to regulate the proliferation of T helper 2 (Th2) cells and group 3 innate lymphoid cells (ILC3s) and the inflammatory microenvironment was remodeled. The in vivo therapeutic results revealed that COS-CaP-QT could relieve the colitis symptoms and maintain the colon length and intestinal barrier integrity.

Application and prospects of nucleic acid nanomaterials in tumor therapy

Cancer poses a great threat to human life, and current cancer treatments, such as radiotherapy, chemotherapy, and surgery, have significant side effects and limitations that hinder their application. Nucleic acid nanomaterials have specific spatial configurations and can be used as nanocarriers to deliver different therapeutic drugs, thereby enabling various biomedical applications, such as biosensors and cancer therapy. In recent decades, a variety of DNA nanostructures have been synthesized, and they have demonstrated remarkable potential in cancer therapy related applications, such as DNA origami structures, tetrahedral framework nucleic acids, and dynamic DNA nanostructures. Importantly, more attention is also being paid to RNA nanostructures, which play an important role in gene therapy. Therefore, this review introduces the developmental history of nucleic acid nanotechnology, summarizes the applications of DNA and RNA nanostructures for tumor treatment, and discusses the development opportunities for nucleic acid nanomaterials in the future.

mRNA-activated DNAzyme nanoprobe for tumor cell precise imaging and gene therapy

A novel Au-nucleic acid nanoprobe, catalyzed by mRNA, has been developed for live cell imaging and precise treatment of tumor cells. This nanoprobe exhibits the remarkable ability to differentiate between tumor cells and normal cells through live cell mRNA imaging, while selectively inducing apoptosis in tumor cells.

Synergistic chemo-photo anticancer therapy by using reversible Diels-Alder dynamic covalent bond mediated polyprodrug amphiphiles and immunoactivation investigation

Highly efficient endocytosis and multi-approach integrated therapeutic tactics are important factors in oncotherapy. With the aid of thermally reversible furan-maleimide dynamic covalent bonds and the "polyprodrug amphiphiles" concept, thermo- and reduction-responsive PEG(-COOH)Fu/MI(-SS-)CPT copolymers were fabricated by the Diels-Alder (D-A) coupling of hydrophilic Fu(-COOH)-PEG and hydrophobic MI(-SS-)-CPT building blocks. The copolymers could self-assemble to form composite nanoparticles with a photothermal conversion reagent (IR780) and maintain excellent stability. In the in vitro simulated environments, the composite nanoparticles could detach Fu(-COOH)-PEG chains by a retro-D-A reaction upon near-infrared light (NIR) irradiation and reduce the size to facilitate endocytosis. Once in the intracellular environment, glutathione (GSH) could trigger a cascade reaction to release active CPT drugs to achieve chemotherapy, which could be further promoted by NIR light induced photothermal therapy. The in vivo mouse tumor model experiments demonstrated that these nanoparticles had an excellent therapeutic effect on solid tumors and inhibited their recurrence. Not only that, the synergistic chemical and optical therapy induced body immune response was also systematically evaluated; the maturation of dendritic cells, the proliferation of T cells, the increase of high mobility group box protein 1, and the decrease of immunosuppressive regulatory T cells confirmed that such synergistic therapy could effectively provide immune protection to the body. We believe such in situ generation of small-sized therapeutic units brought by a dynamically reversible D-A reaction could expand the pathway to design next generation drug delivery systems possessing superior design philosophy and excellent practice effects compared to currently available ones.

DNA Assembly of Plasmonic Nanostructures Enables In Vivo SERS-Based MicroRNA Detection and Tumor Photoacoustic Imaging

Controllable self-assembly of the DNA-linked gold nanoparticle (AuNP) architecture for in vivo biomedical applications remains a key challenge. Here, we describe the use of the programmed DNA tetrahedral structure to control the assembly of three different types of AuNPs (∼20, 10, and 5 nm) by organizing them into defined positioning and arrangement. A DNA-assembled "core-satellite" architecture is built by DNA sequencing where satellite AuNPs (10 and 5 nm) surround a central core AuNP (20 nm). The density and arrangement of the AuNP satellites around the core AuNP were controlled by tuning the size and amount of the DNA tetrahedron functionalized on the core AuNPs, resulting in strong electromagnetic field enhancement derived from hybridized plasmonic coupling effects. By conjugating with the Raman molecule, strong surface-enhanced Raman scattering photoacoustic imaging signals could be generated, which were able to image microRNA-21 and tumor tissues in vivo. These results provided an efficient strategy to build precision plasmonic superstructures in plasmonic-based bioanalysis and imaging.

Self-assembled albumin nanoparticles induce pyroptosis for photodynamic/photothermal/immuno synergistic therapies in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is characterized by a high degree of malignancy, early metastasis, limited treatment, and poor prognosis. Immunotherapy, as a new and most promising treatment for cancer, has limited efficacy in TNBC because of the immunosuppressive tumor microenvironment (TME). Inducing pyroptosis and activating the cyclic guanosine monophosphate-adenosine monophosphate synthase/interferon gene stimulator (cGAS/STING) signaling pathway to upregulate innate immunity have become an emerging strategy for enhancing tumor immunotherapy. In this study, albumin nanospheres were constructed with photosensitizer-IR780 encapsulated in the core and cGAS-STING agonists/H₂S producer-ZnS loaded on the shell (named IR780-ZnS@HSA). In vitro, IR780-ZnS@HSA produced photothermal therapy (PTT) and photodynamic therapy (PDT) effects. In addition, it stimulated immunogenic cell death (ICD) and activated pyroptosis in tumor cells via the caspase-3-GSDME signaling pathway. IR780-ZnS@HSA also activated the cGAS-STING signaling pathway. The two pathways synergistically boost immune response. In vivo, IR780-ZnS@HSA + laser significantly inhibited tumor growth in 4T1 tumor-bearing mice and triggered an immune response, improving the efficacy of the anti-APD-L1 antibody (aPD-L1). In conclusion, IR780-ZnS@HSA, as a novel inducer of pyroptosis, can significantly inhibit tumor growth and improve the efficacy of aPD-L1.

Multifunctional targeted solid lipid nanoparticles for combined photothermal therapy and chemotherapy of breast cancer

Photothermal therapy has emerged as a new promising strategy for the management of cancer, either alone or combined with other therapeutics, such as chemotherapy. The use of nanoparticles for multimodal therapy can improve treatment performance and reduce drug doses and associated side effects. Here we propose the development of a novel multifunctional nanosystem based on solid lipid nanoparticles co-loaded with gold nanorods and mitoxantrone and functionalized with folic acid for dual photothermal therapy and chemotherapy of breast cancer. Nanoparticles were produced using an economically affordable method and presented suitable physicochemical properties for tumor passive accumulation. Upon Near-Infrared irradiation (808 nm, 1.7 W cm^-2, 5 min), nanoparticles could effectively mediate a temperature increase of >20 °C. Moreover, exposure to light resulted in an enhanced release of Mitoxantrone. Furthermore, nanoparticles were non-hemolytic and well tolerated by healthy cells even at high concentrations. The active targeting strategy was found to be successful, as shown by the greater accumulation of the functionalized nanoparticles in MCF-7 cells. Finally, the combined effects of chemotherapy, light-induced drug release and photothermal therapy significantly enhanced breast cancer cell death. Overall, these results demonstrate that the developed lipid nanosystem is an efficient vehicle for breast cancer multimodal therapy.

Photo-controllable burst generation of peroxynitrite based on synergistic interactions of polymeric nitric oxide donors and IR780 for enhancing broad-spectrum antibacterial therapy

The newly attractive peroxynitrite (ONOO^-) therapy can prominently enhance antibacterial therapeutic efficacy. However, it is a great challenge but urgently needed to generate ONOO^- with adjustable release rate and dosage in order to satisfy personalized treatments for different disease types and severities. Herein, PSNO@IR780 nanoparticles are fabricated via co-assembly of an amphiphilic PEG-b-PAASNO block copolymer grafted with abundant nitric oxide (NO) donor units and IR780 as a photothermal and photodynamic agent. Photo-controllable burst generation of ONOO^- from PSNO@IR780 nanoparticles could be realized based on synergistic reactions of rapid NO release induced by increased local temperature and efficiently produced superoxide anion radical (O₂^•-) from IR780. The maximum ONOO^- release dosage is up to 6.73 ± 0.07 µM and release rate is up to 98.1 ± 1.38 nM/s. Furthermore, the ONOO^- release behavior can be precisely manipulated by varying sample concentrations, irradiated durations, output power densities, and laser switches, respectively. Ultra-efficiently generated ONOO^- from biocompatible PSNO@IR780 nanoparticles significantly elevated broad spectrum antibacterial efficiency through damaging bacterial membranes. Thus, PSNO@IR780 nanoparticles may present a new insight into preparation of burst and controllable generating ONOO^- materials, and provide new opportunities for antibacterial therapy. STATEMENT OF SIGNIFICANCE: 1. Polymeric NO donor (PEG-b-PAASNO) grafted with abundant NO donor units was synthesized. 2. PSNO@IR780 nanoparticles were prepared by co-assembly of IR780 and amphiphilic PEG-b-PAASNOpolymer. 3. The maximum ONOO^- release dosage from PSNO@IR780 nanoparticles was 6.73 ± 0.08 µM. 4. The fastest ONOO^- release rate from PSNO@IR780 nanoparticles was 98.1 ± 1.4 nM/s. 5. Ultra-efficiently generated ONOO^- significantly elevated antibacterial efficiency via damaging bac-terial membranes.

High performance carbon dots based prodrug Platform: Image-Guided photodynamic and chemotherapy with On-Demand drug release upon laser irradiation

The design of therapeutic nanoplatforms based on fluorescent carbon dots (CDs) has become a viable strategy because of their aqueous solubility, biocompatibility, and ease of further functionalization. By doping various heteroatoms into pristine CDs structures, we synthesized N-, Cl-, and S-doped CDs (NClS/CDs), as well as Se-, N-, and Cl-doped CDs (NClSe/CDs) with superior optoelectronic properties using rapid and straightforward microwave heating. The quantum efficiencies of these NClS/CDs and NClSe/CDs were enhanced to 30.7 % and 42.9 %, respectively, compared to those of undoped CDs (0.66 %). Owing to their better light absorption properties, NClS/CDs efficiently produced reactive oxygen species (ROS) under 532 nm laser irradiation for photodynamic therapy (PDT). Considering the ROS generation and surface carrier abilities of NClS/CDs, we designed the loading of camptothecin (CPT) drug via a thioketal linker (TL), resulting in h/CDs@CPT nanovesicles (NVs) with a drug-loading efficiency of 46.5 %. Under laser irradiation in an acidic environment, ROS-triggered CPT release was observed, with 50.2 % of CPT released following the breakdown of the ROS-sensitive TL. In vitro cellular studies revealed that h/CDs@CPT NVs possessed minimal cytotoxicity toward HeLa and 4 T1 cancer cells, despite the high clinical efficacy of PDT and ROS-induced chemotherapeutic response under laser treatment. Confocal microscopy of HeLa and 4 T1 cells revealed that h/CDs@CPT NVs produced red-emissive photographs for potential cancer cell detection. Therefore, our study presents an image-guided PDT and chemotherapeutic platform based on h/CDs@CPT NVs, which will be an attractive candidate for future cancer treatment.

Deformable and Disintegrable Multifunctional Integrated Polyprodrug Amphiphiles for Synergistic Phototherapy and Chemotherapy

Multimodal collaborative therapy has been recognized as one of the more effective means to eliminate tumors in the current biomedicine research field as compared with monotherapy. Among them, by taking advantage of its high-precision and controllability, phototherapy has become a mainstay of treatment. However, physical encapsulation of free photosensitive units within nanocarriers was one of the main implementations, which might inevitably result in the photosensitizer leakage and side effect. For this purpose, a kind of multifunctional integrated polyprodrug amphiphiles, P(PFO-IG-CPT)-PEG, were prepared by reversible addition-fragmentation chain transfer polymerization from polymerizable pentadecafluorooctan monomers, indocyanine green monomers, reduction-responsive camptothecin monomers, and acid-responsive PEG based methacrylate monomers (GMA(-OH/-PEG)). The resultant copolymers could self-assemble into spherical nanoparticles in water, performing size-deformability in acidic conditions and subsequent disintegration in reduction environment as demonstrated by in vitro experiments. Furthermore, an enhanced CPT release ratio and rate from nanoparticles could be achieved by a NIR irradiation due to the hyperthermia induced by the covalently linked IG moieties. Not only that, because of the sufficient O₂ content brought by PFO, the NIR light-triggered generation of ¹O₂ was also detected in cells. With the combination of CPT-guided chemotherapy as well as NIR light-guided photo-thermal and photodynamic therapies, fatal and irreversible damage to cancer cells was observed by cell experiments; the implanted tumor size in the mouse model was obviously shrunk upon receiving multimodal collaborative therapy. We speculate that such fabricated nanodiagnosis and treatment systems could meet the growing emergency for effective drug delivery, programmed and on-demand drug release, and multimodal integrated therapy.

In situ assembled titanium carbide-based heterojunctions for the synergistic enhancement of NIR-II photothermal/photodynamic therapy against breast cancer

The combined use of photothermal therapy (PTT) and photodynamic therapy (PDT) could circumvent the drawbacks of each individual therapeutic strategy, resulting in an enhanced antitumor effect. However, the lack of highly effective photo-agents that are irradiation-safe in the biologically transparent window hinder the advancement of phototherapy clinically. Hence, in this study, a charge separation engineering strategy was adopted to fabricate a nanoplatform with heterojunctions, namely, in situ TiO₂-loaded MXene (Ti₃C₂/TiO₂ heterojunctions). This nanoplatform exhibited reduced bandgap (1.68 eV), enhanced NIR-II photothermal conversion efficiency (44.98%), and extended absorption edge compared to pristine TiO₂ for enhanced photodynamic effect. More importantly, the proliferation of tumor cells could be efficiently inhibited at a 5 mm chicken breast depth after 1064 nm laser irradiation, and the intracellular ROS production significantly increased under 660 nm or even 1064 nm laser irradiation with heterojunctions (HJs) compared with that of TiO₂. Moreover, the in vivo data further confirmed that the as-prepared heterojunctions could efficiently eradicate tumors efficiently via improved photothermal effect with NIR-II laser irradiation and upregulated ROS production. Collectively, the reported HJs strategy provides an opportunity for the success of combinational PTT and PDT therapy in tumor treatment.

Design of ROS-Responsive Hyaluronic Acid-Methotrexate Conjugates for Synergistic Chemo-Photothermal Therapy for Cancer

Combining chemotherapy with photothermal therapy (PTT) for cancer treatment could overcome the inherent limitations of both single-modality chemotherapy and PTT. However, the obstacle of accurate drug delivery to tumor sites based on chemo-photothermal remains challenging. This article describes development of a reactive oxygen species (ROS)-responsive hyaluronic acid-based nanoparticle to overcome these drawbacks. Herein, HA-TK-MTX (HTM) was synthesized by a ROS-responsive cleaved thioketal moiety linker (TK) of methotrexate (MTX) and hyaluronic acid (HA). Through hydrophobic interaction and π-π stacking interaction, a photothermal agent IR780 was integrated into the HTM, and the IR780/HTM nanoparticles (IHTM NPs) were obtained. The IHTM NPs show high photostability, excellent photothermal performance, remarkable tumor-targeting ability, and ROS sensibility. Due to the accurate drug delivery ability and superior chemo-photothermal treatment effect of IHTM NPs, the tumor inhibition rate reached 70.95% for 4T1 tumor-bearing mice. This work serves as a precedent for the chemo-photothermal therapy of cancer by rationally designing ROS-responsive nanoparticles.

Therapeutic Applications of Programmable DNA Nanostructures

Deoxyribonucleic acid (DNA) nanotechnology, a frontier in biomedical engineering, is an emerging field that has enabled the engineering of molecular-scale DNA materials with applications in biomedicine such as bioimaging, biodetection, and drug delivery over the past decades. The programmability of DNA nanostructures allows the precise engineering of DNA nanocarriers with controllable shapes, sizes, surface chemistries, and functions to deliver therapeutic and functional payloads to target cells with higher efficiency and enhanced specificity. Programmability and control over design also allow the creation of dynamic devices, such as DNA nanorobots, that can react to external stimuli and execute programmed tasks. This review focuses on the current findings and progress in the field, mainly on the employment of DNA nanostructures such as DNA origami nanorobots, DNA nanotubes, DNA tetrahedra, DNA boxes, and DNA nanoflowers in the biomedical field for therapeutic purposes. We will also discuss the fate of DNA nanostructures in living cells, the major obstacles to overcome, that is, the stability of DNA nanostructures in biomedical applications, and the opportunities for DNA nanostructure-based drug delivery in the future.

A hypoxia-responsive supramolecular formulation for imaging-guided photothermal therapy

Photothermal agents (PTAs) based on organic small-molecule dyes emerge as promising theranostic strategy in imaging and photothermal therapy (PTT). However, hydrophobicity, photodegradation, and low signal-to-noise ratio impede their transformation from bench to bedside. In this study, a novel supramolecular PTT formulation by a stimuli-responsive macrocyclic host is prepared to overcome these obstacles of organic small-molecule PTAs. Methods: Sulfonated azocalix[4]arene (SAC4A) was synthesized as a hypoxia-responsive macrocyclic host. Taking IR780 as an example, the supramolecular nanoformulation IR780@SAC4A was constructed by grinding method, and its solubility, photostability, and photothermal conversion were evaluated. The hypoxia tumor-selective imaging and supramolecular PTT of IR780@SAC4A were further evaluated in vitro and in vivo. Results: IR780@SAC4A is capable of enhancing the solubility, photostability, and photothermal conversion of IR780 significantly, which achieve this supramolecular formulation with good imaging-guided PTT efficacy in vitro and in vivo. Conclusions: This study demonstrates that the supramolecular PTT strategy is a promising cancer theranostic method. Moreover, this supramolecular approach is applicative to construct kinds of supramolecular PTAs, opening a general avenue for extending smart PTT formulations.

Recent advances in constructing high-order DNA structures

Molecular self-assembly is widely used in the fields of biosensors, molecular devices, efficient catalytic materials, and medical biomaterials. As the carrier of genetic information, DNA is a kind of biomacromolecule composed of deoxyribonucleotide units. DNA nanotechnology extends DNA of its original properties as a molecule that stores and transmits genetic information from its biological environment. By taking advantage of its unique base pairing and inherent biocompatibility to produce structurally-defined supramolecular structures. With the continuously development of DNA technology, the assembly method of DNA nanostructures is not only limited on the basis of DNA hybridization but also other biochemical interactions. In this review, we summarize the latest methods used to construct high-order DNA nanostructures. The problems of DNA nanostructures are discussed and the future directions in this field are provided.

Multifunctional phototheranostic nanoplatform based on polydopamine-manganese dioxide-IR780 iodide for effective magnetic resonance imaging-guided synergistic photodynamic/photothermal therapy

Multifunctional phototheranostics combining diagnostic and therapeutic modalities may provide a revolutionary opportunity for cancer treatment. As a promising tumor phototheranostic molecule, IR780 iodide (IR780) shows excellent photodynamic and photothermal performance under near-infrared laser irradiation; however, its hydrophobicity and instability limit its further use in organisms. This work demonstrates the design and development of a multifunctional nanoplatform (PMIDA, referring to polydopamine (PDA)-manganese dioxide (MnO₂)-IR780) for imaging-guided phototherapy. The good biocompatibility of PDA greatly improves the water solubility and photostability of IR780, and its excellent photothermal properties make PMIDA a dual photothermal therapy (PTT). MnO₂-induced generation of oxygen in the tumor microenvironment improves the hypoxia effect and photodynamic therapy (PDT) of IR780. Moreover, Mn²⁺ serves as a decent T₁-weighted magnetic resonance imaging (MRI) probe to guide treatment. Notably, in relevant cellular assays, PMIDA shows high photodynamic and photothermal effects contributing to the final therapeutic effect. The MRI-guided PDT/PTT synergistic therapy effect in vivo is demonstrated by precise tumor diagnosis and complete tumor elimination outcomes. Based on these experiments, PMIDA nanoparticles display promising effects in facilitating intravenous injection of IR780 and achieving magnetic resonance imaging (MRI)-guided phototheranostic efficacy for tumor treatment.

Functionalizing Framework Nucleic-Acid-Based Nanostructures for Biomedical Application

Strategies for functionalizing diverse tetrahedral framework nucleic acids (tFNAs) have been extensively explored since the first successful fabrication of tFNA by Turberfield. One-pot annealing of at least four DNA single strands is the most common method to prepare tFNA, as it optimizes the cost, yield, and speed of assembly. Herein, the focus is on four key merits of tFNAs and their potential for biomedical applications. The natural ability of tFNA to scavenge reactive oxygen species, along with remarkable enhancement in cellular endocytosis and tissue permeability based on its appropriate size and geometry, promotes cell-material interactions to direct or probe cell behavior, especially to treat inflammatory and degenerative diseases. Moreover, the structural programmability of tFNA enables the development of static tFNA-based nanomaterials via engineering of functional oligonucleotides or therapeutic molecules, and dynamic tFNAs via attachment of stimuli-responsive DNA apparatuses, leading to potential applications in targeted therapies, tissue regeneration, antitumor strategies, and antibacterial treatment. Although there are impressive performance and significant progress, the challenges and prospects of functionalizing tFNA-based nanostructures are still indicated in this review.

Dual Tumor Microenvironment Remodeling by Glucose-Contained Radical Copolymer for MRI-Guided Photoimmunotherapy

Aberrant glucose metabolism and immune evasion are recognized as two hallmarks of cancer, which contribute to poor treatment efficiency and tumor progression. Herein, a novel material system consisting of a glucose and TEMPO (2,2,6,6-tetramethylpiperidin-1-yl)oxyl) at the distal ends of PEO-b-PLLA block copolymer (glucose-PEO-b-PLLA-TEMPO), is designed to encapsulate clinical therapeutics CUDC101 and photosensitizer IR780. The specific core-shell rod structure formed by the designed copolymer renders TEMPO radicals excellent stability against reduction-induced magnetic resonance imaging (MRI) silence. Tumor-targeting moiety endowed by glucose provides the radical copolymer outstanding multimodal imaging capabilities, including MRI, photoacoustic imaging, and fluorescence imaging. Efficient delivery of CUDC101 and IR780 is achieved to synergize the antitumor immune activation through IR780-mediated photodynamic therapy (PDT) and CUDC101-triggered CD47 inhibition, showing M1 phenotype polarization of tumor-associated macrophages (TAMs). More intriguingly, this study demonstrates PDT-stimulated p53 can also re-educate TAMs, providing a combined strategy of using dual tumor microenvironment remodeling to achieve the synergistic effect in the transition from cold immunosuppressive to hot immunoresponsive tumor microenvironment.

Overcoming barriers in photodynamic therapy harnessing nano-formulation strategies

Photodynamic therapy (PDT) has been extensively investigated for decades for tumor treatment because of its non-invasiveness, spatiotemporal selectivity, lower side-effects, and immune activation ability. It can be a promising treatment modality in several medical fields, including oncology, immunology, urology, dermatology, ophthalmology, cardiology, pneumology, and dentistry. Nevertheless, the clinical application of PDT is largely restricted by the drawbacks of traditional photosensitizers, limited tissue penetrability of light, inefficient induction of tumor cell death, tumor resistance to the therapy, and the severe pain induced by the therapy. Recently, various photosensitizer formulations and therapy strategies have been developed to overcome these barriers. Significantly, the introduction of nanomaterials in PDT, as carriers or photosensitizers, may overcome the drawbacks of traditional photosensitizers. Based on this, nanocomposites excited by various light sources are applied in the PDT of deep-seated tumors. Modulation of cell death pathways with co-delivered reagents promotes PDT induced tumor cell death. Relief of tumor resistance to PDT with combined therapy strategies further promotes tumor inhibition. Also, the optimization of photosensitizer formulations and therapy procedures reduces pain in PDT. Here, a systematic summary of recent advances in the fabrication of photosensitizers and the design of therapy strategies to overcome barriers in PDT is presented. Several aspects important for the clinical application of PDT in cancer treatment are also discussed.

Self-assembled multifunctional polymeric micelles for tumor-specific bioimaging and synergistic chemo-phototherapy of cancer

Integration of multiple therapies into one nanoplatform holds great promise to overcome the shortcomings of traditional single-modal therapy and achieve favorable antitumor efficacy. Herein, we constructed a dual receptor-targeting nanomicelle system with GSH-responsive drug release for precise fluorescence imaging and superior chemo-phototherapy of cancer. The synthetic amphiphilic hyaluronic acid derivative (FHSV) could self-assemble into nanomicelles in aqueous media. Then, paclitaxel (PTX) and photosensitizer IR780 iodide (IR780) were co-loaded into the micelles by a simple dialysis method. The resulting IR780/PTX/FHSV micelles with a particle size of 150.2 ± 6.9 nm exhibited excellent stability, GSH-responsive drug release and good photothermal/photodynamic efficacy. Once accumulated at the tumor sites, IR780/PTX/FHSV micelles efficiently entered tumor cells through receptor-mediated endocytosis and then rapidly release PTX and IR780 under GSH-rich tumor microenvironment. Upon NIR laser irradiation, IR780 produced local hyperthermia and sufficient reactive oxygen species to promote tumor cells apoptosis and necrosis. The results of in vitro and in vivo experiments consistently demonstrated that compared with single chemotherapy and phototherapy, the chemo-phototherapy could more efficiently kill tumor cells by synergistic antitumor effect. Therefore, our study provides a novel and efficient approach for multimodal treatment of malignant tumor.