"Trojan Horse" Phototheranostics: Fine-Engineering NIR-II AIEgen Camouflaged by Cancer Cell Membrane for Homologous-Targeting Multimodal Imaging-Guided Phototherapy

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

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

Remote Control of Energy Transformation-Based Cancer Imaging and Therapy

Cancer treatment requires precise tumor-specific targeting at specific sites that allows for high-resolution diagnostic imaging and long-term patient-tailorable cancer therapy; while, minimizing side effects largely arising from non-targetability. This can be realized by harnessing exogenous remote stimuli, such as tissue-penetrative ultrasound, magnetic field, light, and radiation, that enable local activation for cancer imaging and therapy in deep tumors. A myriad of nanomedicines can be efficiently activated when the energy of such remote stimuli can be transformed into another type of energy. This review discusses the remote control of energy transformation for targetable, efficient, and long-term cancer imaging and therapy. Such ultrasonic, magnetic, photonic, radiative, and radioactive energy can be transformed into mechanical, thermal, chemical, and radiative energy to enable a variety of cancer imaging and treatment modalities. The current review article describes multimodal energy transformation where a serial cascade or multiple types of energy transformation occur. This review includes not only mechanical, chemical, hyperthermia, and radiation therapy but also emerging thermoelectric, pyroelectric, and piezoelectric therapies for cancer treatment. It also illustrates ultrasound, magnetic resonance, fluorescence, computed tomography, photoluminescence, and photoacoustic imaging-guided cancer therapies. It highlights afterglow imaging that can eliminate autofluorescence for sustained signal emission after the excitation.

Bioinspired AIE Nanomedicine: A Burgeoning Technology for Fluorescence Bioimaging and Phototheranostics

Nanomedicine on the basis of aggregated-induced emission (AIE) luminogens with exceptional potency is growing into a sparkling frontier in fluorescence imaging and phototheranostics. Of particular interest is biomimetic AIE nanomedicine comprised by AIE luminogens and biocarrier, which represents a win-win integration and are recently developed at a tremendous pace, mainly benefiting from the intrinsic advantages including enhanced biocompatibility, prolonged circulation time, specific targeting ability, immune activation, and supremely extraordinary phototheranostic outputs. In view of the inexhaustible and vigorous vitality in the field, this review provides an integrated picture on biomimetic AIE nanomedicine involving the basic concepts, significant breakthroughs, and recent trends. In addition, based on the current achievements, some critical challenges and perspectives are also discussed.

Surface-engineered erythrocyte membrane-camouflage fluorescent bioprobe for precision ovarian cancer surgery

PURPOSE

Fluorescence imaging-guided surgery has been used in oncology. However, for tiny tumors, the current imaging probes are still difficult to achieve high-contrast imaging, leading to incomplete resection. In this study, we achieved precise surgical resection of tiny metastatic cancers by constructing an engineering erythrocyte membrane-camouflaged bioprobe (AR-M@HMSN@P).

METHODS

AR-M@HMSN@P combined the properties of aggregation-induced emission luminogens (AIEgens) named PF3-PPh3 (P), with functional erythrocyte membrane modified by a modular peptide (AR). Interestingly, AR was composed of an asymmetric tripodal pentapeptide scaffold (GGKGG) with three appended modulars: KPSSPPEE (A6) peptide, RRRR (R4) peptide and cholesterol. To verify the specificity of the probe in vitro, SKOV3 cells with overexpression of CD44 were used as the positive group, and HLF cells with low expression of CD44 were devoted as the control group. The AR-M@HMSN@P fluorescence imaging was utilized to provide surgical guidance for the removal of micro-metastatic lesions.

RESULTS

In vivo, the clearance of AR-M@HMSN@P by the immune system was reduced due to the natural properties inherited from erythrocytes. Meanwhile, the A6 peptide on AR-M@HMSN@P was able to specifically target CD44 on ovarian cancer cells, and the electrostatic attraction between the R4 peptide and the cell membrane enhanced the firmness of this targeting. Benefiting from these multiple effects, AR-M@HMSN@P achieved ultra-precise tumor imaging with a signal-to-noise ratio (SNR) of 15.2, making it possible to surgical resection of tumors < 1 mm by imaging guidance.

CONCLUSION

We have successfully designed an engineered fluorescent imaging bioprobe (AR-M@HMSN@P), which can target CD44-overexpressing ovarian cancers for precise imaging and guide the resection of minor tumors. Notably, this work holds significant promise for developing biomimetic probes for clinical imaging-guided precision cancer surgery by exploiting their externally specified functional modifications.

Near-Infrared-II Nanomaterials for Activatable Photodiagnosis and Phototherapy

Near-Infrared-II (NIR-II) spans wavelengths between 1,000 to 1,700 nanometers, featuring deep tissue penetration and reduced tissue scattering and absorption characteristics, providing robust support for cancer treatment and tumor imaging research. This review explores the utilization of activatable NIR-II photodiagnosis and phototherapy based on tumor microenvironments (e. g., reactive oxygen species, pH, glutathione, hypoxia) and external stimulation (e. g., laser, ultrasound, photothermal) for precise tumor treatment and imaging. Special emphasis is placed on the advancements and advantages of activatable NIR-II nanomedicines in novel therapeutic modalities like photodynamic therapy, photothermal therapy, and photoacoustic imaging. This encompasses achieving deep tumor penetration, real-time monitoring of the treatment process, and obtaining high-resolution, high signal-to-noise ratio images even at low material concentrations. Lastly, from a clinical perspective, the challenges faced by activatable NIR-II phototherapy are discussed, alongside potential strategies to overcome these hurdles.

NIR-II light in clinical oncology: opportunities and challenges

Novel strategies utilizing light in the second near-infrared region (NIR-II; 900-1,880 nm wavelengths) offer the potential to visualize and treat solid tumours with enhanced precision. Over the past few decades, numerous techniques leveraging NIR-II light have been developed with the aim of precisely eliminating tumours while maximally preserving organ function. During cancer surgery, NIR-II optical imaging enables the visualization of clinically occult lesions and surrounding vital structures with increased sensitivity and resolution, thereby enhancing surgical quality and improving patient prognosis. Furthermore, the use of NIR-II light promises to improve cancer phototherapy by enabling the selective delivery of increased therapeutic energy to tissues at greater depths. Initial clinical studies of NIR-II-based imaging and phototherapy have indicated impressive potential to decrease cancer recurrence, reduce complications and prolong survival. Despite the encouraging results achieved, clinical translation of innovative NIR-II techniques remains challenging and inefficient; multidisciplinary cooperation is necessary to bridge the gap between preclinical research and clinical practice, and thus accelerate the translation of technical advances into clinical benefits. In this Review, we summarize the available clinical data on NIR-II-based imaging and phototherapy, demonstrating the feasibility and utility of integrating these technologies into the treatment of cancer. We also introduce emerging NIR-II-based approaches with substantial potential to further enhance patient outcomes, while also highlighting the challenges associated with imminent clinical studies of these modalities.

Chemodynamic PtMn Nanocubes for Effective Photothermal ROS Storm a Key Anti-Tumor Therapy in-vivo

Background

Chemodynamic therapy (CDT) is a new treatment approach that is triggered by endogenous stimuli in specific intracellular conditions for generating hydroxyl radicals. However, the efficiency of CDT is severely limited by Fenton reaction agents and harsh reaction conditions.

Methods

Bimetallic PtMn nanocubes were rationally designed and simply synthesized through a one-step high-temperature pyrolysis process by controlling both the nucleation process and the subsequent crystal growth stage. The polyethylene glycol was modified to enhance biocompatibility.

Results

Benefiting from the alloying of Pt nanocubes with Mn doping, the structure of the electron cloud has changed, resulting in different degrees of the shift in electron binding energy, resulting in the increasing of Fenton reaction activity. The PtMn nanocubes could catalyze endogenous hydrogen peroxide to toxic hydroxyl radicals in mild acid. Meanwhile, the intrinsic glutathione (GSH) depletion activity of PtMn nanocubes consumed GSH with the assistance of Mn3+/Mn2+. Upon 808 nm laser irradiation, mild temperature due to the surface plasmon resonance effect of Pt metal can also enhance the Fenton reaction.

Conclusion

PtMn nanocubes can not only destroy the antioxidant system via efficient reactive oxygen species generation and continuous GSH consumption but also propose the photothermal effect of noble metal for enhanced Fenton reaction activity.

Acceptor-donor-acceptor-type molecules with large electrostatic potential difference for effective NIR photothermal therapy

Although acceptor-donor-acceptor (A-D-A)-type molecules offer advantages in constructing NIR absorbing photothermal agents (PTAs) due to their strong intramolecular charge transfer and molecular planarity, their applications in photothermal therapy (PTT) of tumors remain insufficiently explored. In particular, the influence of ESP distribution on the optical properties of A-D-A photosensitizers has not been investigated. Herein, we analyze and compare the difference in ESP distribution between A-D-A-type small molecules and polymers to construct NIR absorbing PTAs with a high extinction coefficient (ε) and high photothermal conversion efficiency (PCE). The calculation results of density functional theory (DFT) indicate that the large ESP difference makes A-D-A-type small molecules superior to their polymer counterparts in realizing tight molecular packing and strong NIR absorbance. Among the as-prepared nanoparticles (NPs), Y6 NPs exhibited an obvious bathochromic shift of absorption peak from 711 nm to 822 nm, with the NIR-II emission extended to 1400 nm. Moreover, a high ε value of 5.69 L g-1 cm-1 and a PCE of 66.3% were attained, making Y6 NPs suitable for PTT. With a concentration of 100 μg mL-1, Y6 NPs in aqueous dispersion yielded a death rate of 93.4% for 4T1 cells upon 808 nm laser irradiation (1 W cm-2) for 10 min, which is comparable with the best results of recently reported PTT agents.

Semiconducting Polymers Based on Asymmetric Thiadiazoloquinoxaline for Augmented In Vivo NIR-II Photoacoustic Imaging

A photoacoustic (PA) imaging technique using the second near-infrared (NIR-II) window has attracted more and more attention because of its merits of deeper penetration depth and higher signal-to-noise (S/N) ratio than that using the first near-infrared (NIR-I) one. However, the design and development of high-performance PA imaging contrast agents in the NIR-II window is still a challenge. A semiconducting polymer, constructed by asymmetric units, exhibits regiorandom characteristics that effectively increase the distortion of the backbone. This increase in the degree of twist can regulate the twisted intramolecular charge transfer (TICT) effect, resulting in an enhancement of the PA signal. In this paper, an asymmetric structural acceptor strategy is developed to improve the PA signals of the resulting semiconducting polymer (PATQ-MP) in the NIR-II window with improved brightness, higher S/N ratio, and better photothermal conversion efficiency compared to polymers with the same main-chain structure containing a symmetric acceptor. DFT analysis showed that PATQ-MP containing an asymmetric acceptor monomer had a larger dihedral angle, which effectively improved the PA signal intensity by enhancing the TICT effect. The PEG-encapsulated PATQ-MP nanoparticles exhibit promising performance in the PA imaging of mouse tumors in vivo, demonstrating the clear identification of microvessels as small as 100 μm along with rapid metabolism within a span of 5 h. Therefore, this work provides a unique molecular design strategy for improving the signal intensity of PA imaging in the NIR-II window.

A Self-Delivery Nanodrug Simultaneously Inhibits COX-2/PGE2 Mediated Inflammation and Downregulates PD-L1 to Boost Photoimmunotherapy

Phototherapy promotes anti-tumor immunity by inducing immunogenic cell death (ICD), However, the accompanying inflammatory responses also trigger immunosuppression, attenuating the efficacy of photo-immunotherapy. Herein, they co-assembled a cell-membrane targeting chimeric peptide C16-Cypate-RRKK-PEG8-COOH (CCP) and anti-inflammatory diclofenac (DA) to develop a nanodrug (CCP@DA) that both enhances the immune effect of phototherapy and weakens the inflammation-mediated immunosuppression. CCP@DA achieves cell membrane-targeting photodynamic and photothermal synergistic therapies to damage programmed death ligand 1 (PD-L1) and induce a strong ICD to activate anti-tumor response. Simultaneously, the released DA inhibits the cycoperoxidase-2 (COX-2)/prostaglandin E2 (PGE2) pathway in tumor cells to inhibit pro-tumor inflammation and further down-regulate PD-L1 expression to relieve the immunosuppressive microenvironment. CCP@DA significantly inhibited tumor growth and inflammation both in vitro and in vivo, while maintaining a potent anti-tumor immune response. Additionally, it exhibits excellent anti-metastatic capabilities and prolongs mouse survival time with a single dose and low levels of near-infrared (NIR) light exposure. This work provides a valuable strategy to control the therapy-induced inflammation for high-efficiency photoimmunotherapy.

Planar-structured thiadiazoloquinoxaline-based NIR-II dye for tumor phototheranostics

Second near-infrared (NIR-II) fluorescence imaging shows huge application prospects in clinical disease diagnosis and surgical navigation, while it is still a big challenge to exploit high performance NIR-II dyes with long-wavelength absorption and high fluorescence quantum yield. Herein, based on planar π-conjugated donor-acceptor-donor systems, three NIR-II dyes (TP-DBBT, TP-TQ1, and TP-TQ2) were synthesized with bulk steric hindrance, and the influence of acceptor engineering on absorption/emission wavelengths, fluorescence efficiency and photothermal properties was systematically investigated. Compared with TP-DBBT and TP-TQ2, the TP-TQ1 based on 6,7-diphenyl-[1,2,5]thiadiazoloquinoxaline can well balance absorption/emission wavelengths, NIR-II fluorescence brightness and photothermal effects. And the TP-TQ1 nanoparticles (NPs) possess high absorption ability at a peak absorption of 877 nm, with a high relative quantum yield of 0.69% for large steric hindrance hampering the close π-π stacking interactions. Furthermore, the TP-TQ1 NPs show a desirable photothermal conversion efficiency of 48% and good compatibility. In vivo experiments demonstrate that the TP-TQ1 NPs can serve as a versatile theranostic agent for NIR-II fluorescence/photoacoustic imaging-guided tumor phototherapy. The molecular planarization strategy provides an approach for designing efficient NIR-II fluorophores with extending absorption/emission wavelength, high fluorescence brightness, and outstanding phototheranostic performance.

Thiophene π-Bridge Manipulation of NIR-II AIEgens for Multimodal Tumor Phototheranostics

The fabrication of a multimodal phototheranostic platform on the basis of single-component theranostic agent to afford both imaging and therapy simultaneously, is attractive yet full of challenges. The emergence of aggregation-induced emission luminogens (AIEgens), particularly those emit fluorescence in the second near-infrared window (NIR-II), provides a powerful tool for cancer treatment by virtue of adjustable pathway for radiative/non-radiative energy consumption, deeper penetration depth and aggregation-enhanced theranostic performance. Although bulky thiophene π-bridges such as ortho-alkylated thiophene, 3,4-ethoxylene dioxythiophene and benzo[c]thiophene are commonly adopted to construct NIR-II AIEgens, the subtle differentiation on their theranostic behaviours has yet to be comprehensively investigated. In this work, systematical investigations discovered that AIEgen BT-NS bearing benzo[c]thiophene possesses acceptable NIR-II fluorescence emission intensity, efficient reactive oxygen species generation, and high photothermal conversion efficiency. Eventually, by using of BT-NS nanoparticles, unprecedented performance on NIR-II fluorescence/photoacoustic/photothermal imaging-guided synergistic photodynamic/photothermal elimination of tumors was demonstrated. This study thus offers useful insights into developing versatile phototheranostic systems for clinical trials.

An NIR-II Excitable AIE Small Molecule with Multimodal Phototheranostic Features for Orthotopic Breast Cancer Treatment

One-for-all phototheranostics, referring to a single component simultaneously exhibiting multiple optical imaging and therapeutic modalities, has attracted significant attention due to its excellent performance in cancer treatment. Benefitting from the superiority in balancing the diverse competing energy dissipation pathways, aggregation-induced emission luminogens (AIEgens) are proven to be ideal templates for constructing one-for-all multimodal phototheranostic agents. However, to this knowledge, the all-round AIEgens that can be triggered by a second near-infrared (NIR-II, 1000-1700 nm) light have not been reported. Given the deep tissue penetration and high maximum permissible exposure of the NIR-II excitation light, herein, this work reports for the first time an NIR-II laser excitable AIE small molecule (named BETT-2) with multimodal phototheranostic features by taking full use of the advantage of AIEgens in single molecule-facilitated versatility as well as synchronously maximizing the molecular donor-acceptor strength and conformational distortion. As formulated into nanoparticles (NPs), the high performance of BETT-2 NPs in NIR-II light-driven fluorescence-photoacoustic-photothermal trimodal imaging-guided photodynamic-photothermal synergistic therapy of orthotopic mouse breast tumors is fully demonstrated by the systematic in vitro and in vivo evaluations. This work offers valuable insights for developing NIR-II laser activatable one-for-all phototheranostic systems.

Recent Advances on NIR-II Light-Enhanced Chemodynamic Therapy

Chemodynamic therapy (CDT) is a particular oncological therapeutic strategy by generates the highly toxic hydroxyl radical (•OH) from the dismutation of endogenous hydrogen peroxide (H2O2) via Fenton or Fenton-like reactions. However, single CDT therapies have been limited by unsatisfactory efficacy. Enhanced chemodynamic therapy (ECDT) triggered by near-infrared (NIR) is a novel therapeutic modality based on light energy to improve the efficiency of Fenton or Fenton-like reactions. However, the limited penetration and imaging capability of the visible (400-650 nm) and traditional NIR-I region (650-900 nm) light-amplified CDT restrict the prospects for its clinical application. Combined with the high penetration/high precision imaging characteristics of the second near-infrared (NIR-II,) nanoplatform, it is expected to kill deep tumors efficiently while imaging the treatment process in real-time, and more notably, the NIR-II region radiation with wavelengths above 1000 nm can minimize the irradiation damage to normal tissues. Such NIR-II ECDT nanoplatforms have greatly improved the effectiveness of CDT therapy and demonstrated extraordinary potential for clinical applications. Accordingly, various strategies have been explored in the past years to improve the efficiency of NIR-II Enhanced CDT. In this review, the mechanisms and strategies used to improve the performance of NIR-II-enhanced CDT are outlined.

Cell Membrane-Coated Nanoparticles for Precision Medicine: A Comprehensive Review of Coating Techniques for Tissue-Specific Therapeutics

Nanoencapsulation has become a recent advancement in drug delivery, enhancing stability, bioavailability, and enabling controlled, targeted substance delivery to specific cells or tissues. However, traditional nanoparticle delivery faces challenges such as a short circulation time and immune recognition. To tackle these issues, cell membrane-coated nanoparticles have been suggested as a practical alternative. The production process involves three main stages: cell lysis and membrane fragmentation, membrane isolation, and nanoparticle coating. Cell membranes are typically fragmented using hypotonic lysis with homogenization or sonication. Subsequent membrane fragments are isolated through multiple centrifugation steps. Coating nanoparticles can be achieved through extrusion, sonication, or a combination of both methods. Notably, this analysis reveals the absence of a universally applicable method for nanoparticle coating, as the three stages differ significantly in their procedures. This review explores current developments and approaches to cell membrane-coated nanoparticles, highlighting their potential as an effective alternative for targeted drug delivery and various therapeutic applications.

Cancer Cell Membrane-Based Materials for Biomedical Applications

The nanodelivery system provides a novel direction for disease diagnosis and treatment; however, its delivery effectiveness is restricted by the short biological half-life and inadequate tumor targeting. The immune evasion properties and homologous targeting capabilities of natural cell membranes, particularly those of cancer cell membranes (CCM), have gained significant interest. The integration of CCM and nanoparticles has resulted in the emergence of CCM-based nanoplatforms (CCM-NPs), which have gained significant attention due to their unique properties. CCM-NPs not only prolong the blood circulation time of core nanoparticles, but also direct them for homologous tumor targeting. Herein, the history and development of CCM-NPs as well as how these platforms have been used for biomedical applications are discussed. The application of CCM-NPs for cancer therapy will be described in detail. Translational efforts are currently under way and further research to address key areas of need will ultimately be required to facilitate the successful clinical adoption of CCM-NPs.

Platelet membrane-derived biomimetic microbubbles with enhanced targeting ability for the early detection of myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI) is a widely recognized cardiovascular disease that significantly impacts the prognosis of patients undergoing myocardial infarction recanalization. This condition can be fatal and involves complex pathophysiological mechanisms. Early diagnosis of MIRI is crucial to minimize myocardial damage and reducing mortality. Based on the inherent relationship between platelets and MIRI, we developed biomimetic microbubbles coated with platelet membrane (MB-pla) for early identification of MIRI. The MB-pla were prepared through a recombination process involving platelet membrane obtained from rat whole blood and phospholipids, blended in appropriate proportions. By coating the microbubbles with platelet membrane, MB-pla acquired various adhesion molecules, thereby gaining the capability to selectively adhere to damaged endothelial cells in the context of MIRI. In vitro experiments demonstrated that MB-pla exhibited remarkable targeting characteristics, particularly toward type IV collagen and human umbilical vein endothelial cells that had been injured through hypoxia/reoxygenation procedures. In a rat model of MIRI, the signal intensity produced by MB-pla was notably higher than that of control microbubbles. These findings were consistent with results obtained from fluorescence imaging of isolated hearts and immunofluorescence staining of tissue sections. In conclusion, MB-pla has great potential as a non-invasive early detection method for MIRI. Furthermore, this approach can potentially find application in other conditions involving endothelial injury in the future.

Photonic control of image-guided ferroptosis cancer nanomedicine

Photonic nanomaterials, characterized by their remarkable photonic tunability, empower a diverse range of applications, including cutting-edge advances in cancer nanomedicine. Recently, ferroptosis has emerged as a promising alternative strategy for effectively killing cancer cells with minimizing therapeutic resistance. Novel design of photonic nanomaterials that can integrate photoresponsive-ferroptosis inducers, -diagnostic imaging, and -synergistic components provide significant benefits to effectively trigger local ferroptosis. This review provides a comprehensive overview of recent advancements in photonic nanomaterials for image-guided ferroptosis cancer nanomedicine, offering insights into their strengths, constraints, and their potential as a future paradigm in cancer treatment.

Ultrasound-nanovesicles interplay for theranostics

Nanovesicles (NVs) are widely used in the treatment and diagnosis of diseases due to their excellent vascular permeability, good biocompatibility, high loading capacity, and easy functionalization. However, their yield and in vivo penetration depth limitations and their complex preparation processes still constrain their application and development. Ultrasound, as a fundamental external stimulus with deep tissue penetration, concentrated energy sources, and good safety, has been proven to be a patient-friendly and highly efficient strategy to overcome the restrictions of traditional clinical medicine. Recent research has shown that ultrasound can drive the generation of NVs, increase their yield, simplify their preparation process, and provide direct therapeutic effects and intelligent control to enhance the therapeutic effect of NVs. In addition, NVs, as excellent drug carriers, can enhance the targeting efficiency of ultrasound-based sonodynamic therapy or sonogenetic regulation and improve the accuracy of ultrasound imaging. This review provides a detailed introduction to the classification, generation, and modification strategies of NVs, emphasizing the impact of ultrasound on the formation of NVs and summarizing the enhanced treatment and diagnostic effects of NVs combined with ultrasound for various diseases.

Fused-Ring Pyrrole-Based Near-Infrared Emissive Organic RTP Material for Persistent Afterglow Bioimaging

Organic near-infrared room temperature phosphorescence (RTP) materials offer remarkable advantages in bioimaging due to their characteristic time scales and background noise elimination. However, developing near-infrared RTP materials for deep tissue imaging still faces challenges since the small band gap may increase the non-radiative decay, resulting in weak emission and short phosphorescence lifetime. In this study, fused-ring pyrrole-based structures were employed as the guest molecules for the construction of long wavelength emissive RTP materials. Compared to the decrease of the singlet energy level, the triplet energy level showed a more effectively decrease with the increase of the conjugation of the substituent groups. Moreover, the sufficient conjugation of fused ring structures in the guest molecule suppresses the non-radiative decay of triplet excitons. Therefore, a near-infrared RTP material (764 nm) was achieved for deep penetration bioimaging. Tumor cell membrane is used to coat RTP nanoparticles (NPs) to avoid decreasing the RTP performance compared to traditional coating by amphiphilic surfactants. RTP NPs with tumor-targeting properties show favorable phosphorescent properties, superior stability, and excellent biocompatibility. These NPs are applied for time-resolved luminescence imaging to eliminate background interference with excellent tissue penetration. This study provides a practical solution to prepare long-wavelength and long-lifetime organic RTP materials and their applications in bioimaging.

Reviewing the evolutive ACQ-to-AIE transformation of photosensitizers for phototheranostics

Photodynamic therapy (PDT) represents an emerging noninvasive treatment technique for cancers and various nonmalignant diseases, including infections. During the process of PDT, the physical and chemical properties of photosensitizers (PSs) critically determine the effectiveness of PDT. Traditional PSs have made great progress in clinical applications. One of the challenges is that traditional PSs suffer from aggregation-caused quenching (ACQ) due to their discotic structures. Recently, aggregation-induced emission PSs (AIE-PSs) with a twisted propeller-shaped conformation have been widely concerned because of high reactive oxygen species (ROS) generation efficiency, strong fluorescence efficiency, and resistance to photobleaching. However, AIE-PSs also have some disadvantages, such as short absorption wavelengths and insufficient molar absorption coefficient. When the advantages and disadvantages of AIE-PSs and ACQ-PSs are complementary, combining ACQ-PSs and AIE-PSs is a "win-to-win" strategy. As far as we know, the conversion of traditional representative ACQ-PSs to AIE-PSs for phototheranostics has not been reviewed. In the review, we summarize the recent progress on the ACQ-to-AIE transformation of PSs and the strategies to achieve desirable theranostic applications. The review would be helpful to design more efficient ACQ-AIE-PSs in the future and to accelerate the development and clinical application of PDT.

Cell Membrane Biomimetic Nano-Delivery Systems for Cancer Therapy

Nano-delivery systems have demonstrated great promise in the therapy of cancer. However, the therapeutic efficacy of conventional nanomedicines is hindered by the clearance of the blood circulation system and the physiological barriers surrounding the tumor. Inspired by the unique capabilities of cells within the body, such as immune evasion, prolonged circulation, and tumor-targeting, there has been a growing interest in developing cell membrane biomimetic nanomedicine delivery systems. Cell membrane modification on nanoparticle surfaces can prolong circulation time, activate tumor-targeting, and ultimately improve the efficacy of cancer treatment. It shows excellent development potential. This review will focus on the advancements in various cell membrane nano-drug delivery systems for cancer therapy and the obstacles encountered during clinical implementation. It is hoped that such discussions will inspire the development of cell membrane biomimetic nanomedical systems.

Tumor Microenvironment-Responsive One-for-All Molecular-Engineered Nanoplatform Enables NIR-II Fluorescence Imaging-Guided Combinational Cancer Therapy

The activable NIR-based phototheranostic nanoplatform (NP) is considered an efficient and reliable tumor treatment due to its strong targeting ability, flexible controllability, minimal side effects, and ideal therapeutic effect. This work describes the rational design of a second near-infrared (NIR-II) fluorescence imaging-guided organic phototheranostic NP (FTEP-TBFc NP). The molecular-engineered phototheranostic NP has a sensitive response to glutathione (GSH), generating hydrogen sulfide (H2S) gas, and delivering ferrocene molecules in the tumor microenvironment (TME). Under 808 nm irradiation, FTEP-TBFc could not only simultaneously generate fluorescence, heat, and singlet oxygen but also greatly enhance the generation of reactive oxygen species to improve chemodynamic therapy (CDT) and photodynamic therapy (PDT) at a biosafe laser power of 0.33 W/cm2. H2S inhibits the activity of catalase and cytochrome c oxidase (COX IV) to cause the enhancement of CDT and hypothermal photothermal therapy (HPTT). Moreover, the decreased intracellular GSH concentration further increases CDT's efficacy and downregulates glutathione peroxidase 4 (GPX4) for the accumulation of lipid hydroperoxides, thus causing the ferroptosis process. Collectively, FTEP-TBFc NPs show great potential as a versatile and efficient NP for specific tumor imaging-guided multimodal cancer therapy. This unique strategy provides new perspectives and methods for designing and applying activable biomedical phototheranostics.

Dual Activation of Calcium Channels Using Near-Infrared Responsive Conjugated Oligomer Nanoparticles for Precise Regulation of Blood Glucose Homeostasis

The rarity of efficient tools with spatiotemporal resolution and biocompatibility capabilities remains a major challenge for further progress and application of signaling manipulation. Herein, biomimetic conjugated oligomeric nanoparticles (CM-CONs) were developed to precisely modulate blood glucose homeostasis via the two-pronged activation of calcium channels. Under near-infrared (NIR) laser irradiation, CM-CONs efficiently generate local heat and reactive oxygen species (ROS), thereby simultaneously activating thermosensitive transient receptor potential V1 (TRPV1) and ROS-sensitive transient receptor potential A1 (TRPA1) calcium channels in small intestinal endocrine cells. The activation of the channels mediates inward calcium flow and then promotes glucagon-like peptide (GLP-1) secretion. Both in vitro and in vivo studies indicate that CM-CONs effectively regulate glucose homeostasis in diabetic model mice upon NIR light irradiation. This work develops a two-pronged attack strategy for accurately controlling blood glucose homeostasis, holding great prospects in the treatment for diabetes.

Tumor-derived systems as novel biomedical tools-turning the enemy into an ally

Cancer is a complex illness that presents significant challenges in its understanding and treatment. The classic definition, "a group of diseases characterized by the uncontrolled growth and spread of abnormal cells in the body," fails to convey the intricate interaction between the many entities involved in cancer. Recent advancements in the field of cancer research have shed light on the role played by individual cancer cells and the tumor microenvironment as a whole in tumor development and progression. This breakthrough enables the utilization of the tumor and its components as biological tools, opening new possibilities. This article delves deeply into the concept of "tumor-derived systems", an umbrella term for tools sourced from the tumor that aid in combatting it. It includes cancer cell membrane-coated nanoparticles (for tumor theranostics), extracellular vesicles (for tumor diagnosis/therapy), tumor cell lysates (for cancer vaccine development), and engineered cancer cells/organoids (for cancer research). This review seeks to offer a complete overview of the tumor-derived materials that are utilized in cancer research, as well as their current stages of development and implementation. It is aimed primarily at researchers working at the interface of cancer biology and biomedical engineering, and it provides vital insights into this fast-growing topic.

Reactive Oxygen Species-Responsive Sequentially Targeted AIE Fluorescent Probe for Precisely Identifying the Atherosclerotic Plaques

The formation of atherosclerosis is the root cause of various cardiovascular diseases (CVDs). Therefore, effective CVD interventions call for precise identification of the plaques to aid in clinical treatment of such diseases. Herein, a reactive oxygen species (ROS)-responsive sequentially targeted fluorescent probe is developed for atherosclerotic plaque recognition. An aggregation-induced emission active fluorophore is linked to maleimide (polyethylene glycol) hydroxyl with a ROS-responsive cleavable bond, which is further functionalized with CLIKKPF peptide (TPAMCF) for specifically binding to phosphatidylserine of the foam cells. After being assembled in aqueous medium, TPAMCF nanoparticles can efficiently accumulate in the plaques through the high affinity of CLIKKPF to the externalized phosphatidylserine of the foam cells. Activated by the locally accumulated ROS in foam cells, the nanoparticles are interrupted, and then TPA can be released and subsequently identify the lipid droplets inside the foam cells to achieve fluorescence imaging of the plaques. Such nanoprobes have the favorable ROS response performance and exhibit a special target binding to the foam cells in vitro. In addition, nanoprobe-based fluorescence imaging permitted the high-contrast and precise detection of atherosclerosis specimens ex vivo. Therefore, as a promising fluorescent probe, TPAMCF is capable of being a potential candidate for the detection of atherosclerotic plaque.

Functional Materials for Subcellular Targeting Strategies in Cancer Therapy: Progress and Prospects

Neoadjuvant and adjuvant therapies have made significant progress in cancer treatment. However, tumor adjuvant therapy still faces challenges due to the intrinsic heterogeneity of cancer, genomic instability, and the formation of an immunosuppressive tumor microenvironment. Functional materials possess unique biological properties such as long circulation times, tumor-specific targeting, and immunomodulation. The combination of functional materials with natural substances and nanotechnology has led to the development of smart biomaterials with multiple functions, high biocompatibilities, and negligible immunogenicities, which can be used for precise cancer treatment. Recently, subcellular structure-targeting functional materials have received particular attention in various biomedical applications including the diagnosis, sensing, and imaging of tumors and drug delivery. Subcellular organelle-targeting materials can precisely accumulate therapeutic agents in organelles, considerably reduce the threshold dosages of therapeutic agents, and minimize drug-related side effects. This review provides a systematic and comprehensive overview of the research progress in subcellular organelle-targeted cancer therapy based on functional nanomaterials. Moreover, it explains the challenges and prospects of subcellular organelle-targeting functional materials in precision oncology. The review will serve as an excellent cutting-edge guide for researchers in the field of subcellular organelle-targeted cancer therapy.

NIR-II Nanoprobes: A Review of Components-Based Approaches to Next-Generation Bioimaging Probes

Fluorescence and photoacoustic imaging techniques offer valuable insights into cell- and tissue-level processes. However, these optical imaging modalities are limited by scattering and absorption in tissue, resulting in the low-depth penetration of imaging. Contrast-enhanced imaging in the near-infrared window improves imaging penetration by taking advantage of reduced autofluorescence and scattering effects. Current contrast agents for fluorescence and photoacoustic imaging face several limitations from photostability and targeting specificity, highlighting the need for a novel imaging probe development. This review covers a broad range of near-infrared fluorescent and photoacoustic contrast agents, including organic dyes, polymers, and metallic nanostructures, focusing on their optical properties and applications in cellular and animal imaging. Similarly, we explore encapsulation and functionalization technologies toward building targeted, nanoscale imaging probes. Bioimaging applications such as angiography, tumor imaging, and the tracking of specific cell types are discussed. This review sheds light on recent advancements in fluorescent and photoacoustic nanoprobes in the near-infrared window. It serves as a valuable resource for researchers working in fields of biomedical imaging and nanotechnology, facilitating the development of innovative nanoprobes for improved diagnostic approaches in preclinical healthcare.

Nanoparticle-Based Photothermal Therapy for Breast Cancer Noninvasive Treatment

Rapid advancements in materials science and nanotechnology, intertwined with oncology, have positioned photothermal therapy (PTT) as a promising noninvasive treatment strategy for cancer. The breast's superficial anatomical location and aesthetic significance render breast cancer a particularly pertinent candidate for the clinical application of PTT following melanoma. This review comprehensively explores the research conducted on the various types of nanoparticles employed in PTT for breast cancer and elaborates on their specific roles and mechanisms of action. The integration of PTT with existing clinical therapies for breast cancer is scrutinized, underscoring its potential for synergistic outcomes. Additionally, the mechanisms underlying PTT and consequential modifications to the tumor microenvironment after treatment are elaborated from a medical perspective. Future research directions are suggested, with an emphasis on the development of integrative platforms that combine multiple therapeutic approaches and the optimization of nanoparticle synthesis for enhanced treatment efficacy. The goal is to push the boundaries of PTT toward a comprehensive, clinically applicable treatment for breast cancer.