Rethinking cancer nanotheranostics

Acid and phosphatase-triggered release and trapping of a prodrug on cancer cell enhance its chemotherapy

Using anticancer drug-encapsulated nanocarriers to actively target tumors is a promising chemotherapy strategy. Nevertheless, premature release of the drugs in tumor microenvironment (TME) or low tumor targeting efficiency of the nanocarriers significantly reduces its therapeutic efficiency. Herein, we propose a release-and-trapping strategy that significantly enhances the chemotherapeutic efficiency of an anticancer drug camptothecin. TME acid triggers the release of its prodrug from the nanocarrier and thereafter phosphatase instructs the prodrug to form hydrogel to trap the nanocarrier on cancer cell membrane. As trapped nanocarrier facilitates cell uptake of the prodrug and its intracellular carboxylesterase-mediated hydrolysis to release camptothecin. In vitro studies showed that the prodrug release from nanocarrier was maximized at pH 6.5. In tumor-bearing mice, our release-and-trapping strategy significantly prolonged the retention of the nanocarrier in tumor and significantly enhanced the anticancer efficacy of camptothecin. We propose that our release-and-trapping strategy be applied for more efficient cancer treatment in the future.

Dual blockade of GSTK1 and CD47 improves macrophage-mediated phagocytosis on cancer cells

CD47 is a crucial anti-phagocytic signal in regulating macrophage responses and its manipulation offers the therapeutic potential in cancer treatment. However, in many cases, blockade of CD47 by itself is insufficient to activate macrophage effectively, indicating other unidentified phagocytosis-regulating factors to resist the macrophage activity. In this study, a genome-wide human CRISPR-Cas9 library was developed for comprehensive screening of phagocytosis-regulating factors in the context of CD47 blockade. The screening results identified GSTK1 as a potential anti-phagocytic signal counteracting the efficacy of CD47-based phagocytosis. The disruption of GSTK1 significantly increased the phagocytosis rate of cancer cells by macrophages in combination with anti-CD47 antibody. Further mechanism investigation unveiled that GSTK1 blockade increased the membrane exposure of calreticulin in different cancer cells, which might be the primary mechanism driving enhanced macrophage-mediated phagocytosis. To this end, siGSTK1-loaded nanoparticles (siGSTK1-LNPs) were designed to suppress the GSTK1 expression efficiently. The comparable phagocytosis efficacy was also observed when combining siGSTK1-LNPs with anti-CD47 antibody. Above all, GSTK1 blockade was identified as a promising and feasible stimulus for enhancing the effectiveness of anti-CD47 antibody, introducing a novel and effective combination approach in cancer immunotherapy.

Diagnostics of brain tumor in the early stage: current status and future perspectives

Early diagnosis of brain tumors is challenging due to their complexity and delicate structure. Conventional imaging techniques like MRI, CT, and PET are unable to provide detailed visualization of early-stage brain tumors. Early-stage detection of brain tumors is vital for enhancing patient outcomes and survival rates. So far, several scientists have dedicated their efforts to innovating advanced diagnostic probes to efficiently cross the BBB and selectively target brain tumors for optimal imaging. The integration of these techniques presents a viable pathway for non-invasive, accurate, and early-stage tumor identification. Herein, we provide a timely update on the various imaging probes and potential challenges for the diagnosis of early-stage brain tumors. Furthermore, this review highlights the significance of integrating advanced imaging probes for improving the early detection of brain tumors, ultimately enhancing treatment outcomes. Hopefully, this review will stimulate the interest of researchers to accelerate the development of new imaging probes and even their clinical translation for improving the early diagnosis of brain tumors.

Emerging magic bullet: subcellular organelle-targeted cancer therapy

The therapeutic efficacy of anticancer drugs heavily relies on their concentration and retention at the corresponding target site. Hence, merely increasing the cellular concentration of drugs is insufficient to achieve satisfactory therapeutic outcomes, especially for the drugs that target specific intracellular sites. This necessitates the implementation of more precise targeting strategies to overcome the limitations posed by diffusion distribution and nonspecific interactions within cells. Consequently, subcellular organelle-targeted cancer therapy, characterized by its exceptional precision, have emerged as a promising approach to eradicate cancer cells through the specific disruption of subcellular organelles. Owing to several advantages including minimized dosage and side effect, optimized efficacy, and reversal of multidrug resistance, subcellular organelle-targeted therapies have garnered significant research interest in recent years. In this review, we comprehensively summarize the distribution of drug targets, targeted delivery strategies at various levels, and sophisticated strategies for targeting specific subcellular organelles. Additionally, we highlight the significance of subcellular targeting in cancer therapy and present essential considerations for its clinical translation.

Pillar[n]arene-Based Supramolecular Nanodrug Delivery Systems for Cancer Therapy

Macrocyclic supramolecular materials play an important role in encapsulating anticancer drugs to improve the anticancer efficiency and reduce the toxicity to normal tissues through host-guest interactions. Among them, pillar[n]arenes, as an emerging class of supramolecular macrocyclic compounds, have attracted increasing attention in drug delivery and drug-controlled release due to their high biocompatibility, excellent host-guest chemistry, and simplicity of modification. In this review, we summarize the research progress of pillar[n]arene-based supramolecular nanodrug delivery systems (SNDs) in recent years in the field of tumor therapy, including drug-controlled release, imaging diagnostics and therapeutic modalities. Furthermore, the opportunities and major limitations of pillar[n]arene-based SNDs for tumor therapy are discussed.

Mitoxantrone-Encapsulated ZIF-8 Enhances Chemo-Immunotherapy via Amplified Immunogenic Cell Death

Chemo-immunotherapy, combining systemic chemotherapeutic drugs and immune checkpoint blockers, is a promising paradigm in cancer treatment. However, challenges such as limited induction of immune responses and systemic immune toxicity have hindered its clinical applications. Here, a zeolite imidazolate framework-8 (ZIF-8) that encapsulates mitoxantrone (MIT), an immune cell death (ICD)-inducing chemotherapeutic agent (MIT@ZIF-8), is synthesized using a one-pot aqueous-phase process. ZIF-8 serves as a dual-functional nanomaterial for chemo-immunotherapy: a carrier to enhance tumor uptake of MIT for improved chemotherapy efficacy, and a pyroptosis inducer to amplify MIT-induced ICD for augmented anti-tumor immune responses. As a result, in vivo administration of MIT@ZIF-8 markedly inhibits tumor growth in both immunologically "hot" colon cancer and immunologically "cold" prostate cancer. Moreover, MIT@ZIF-8 treatment increases the abundance of cytotoxic CD8+ T cells and reduces the amount of immunosuppressive regulatory T cells in tumors, thereby enhancing anti-tumor immunity and sensitizing prostate cancer to anti-CTLA-4 immunotherapy. In summary, MIT@ZIF-8 offers a highly translational approach for chemo-immunotherapy.

Nanotechnology-based drug delivery system for the diagnosis and treatment of ovarian cancer

Current research in nanotechnology is improving or developing novel applications that could improve disease diagnosis or treatment. This study highlights several nanoscale drug delivery technologies, such as nano micelles, nanocapsules, nanoparticles, liposomes, branching dendrimers, and nanostructured lipid formulations for the targeted therapy of ovarian cancer (OC), to overcome the limitations of traditional delivery. Because traditional drug delivery to malignant cells has intrinsic flaws, new nanotechnological-based treatments have been developed to address these conditions. Ovarian cancer is the most common gynecological cancer and has a higher death rate because of its late diagnosis and recurrence. This review emphasizes the discipline of medical nanotechnology, which has made great strides in recent years to solve current issues and enhance the detection and treatment of many diseases, including cancer. This system has the potential to provide real-time monitoring and diagnostics for ovarian cancer treatment, as well as simultaneous delivery of therapeutic agents.

Translational Selenium Nanoparticles Promotes Clinical Non-small-cell Lung Cancer Chemotherapy via Activating Selenoprotein-driven Immune Manipulation

Reconstructing the tumor immune microenvironment is an effective strategy to enhance therapeutic efficacy limited by immunosuppression in non-small-cell lung cancer (NSCLC). In this study, it is found that selenium (Se) depletion and immune dysfunction are present in patients with advanced NSCLC compared with healthy volunteers. Surprisingly, Se deficiency resulted in decreased immunity and accelerated rapid tumor growth in the mice model, which further reveals that the correlation between micronutrient Se and lung cancer progression. This pioneering work achieves 500-L scale production of Se nanoparticles (SeNPs) at GMP level and utilizes it to reveal how and why the trace element Se can enhance clinical immune-mediated treatment efficacy against NSCLC. The results found that translational SeNPs can promote the proliferation of NK cells and enhance its cytotoxicity against cancer cells by activating mTOR signaling pathway driven by GPXs to regulate the secretion of cytokines to achieve an antitumor response. Moreover, a clinical study of an Investigator-initiated Trial shows that translational SeNPs supplementation in combination with bevacizumab/cisplatin/pemetrexed exhibits enhanced therapeutic efficacy with an objective response rate of 83.3% and a disease control rate of 100%, through potentiating selenoprotein-driven antitumor immunity. Taken together, this study, for the first time, highlights the translational SeNPs-enhanced therapeutic efficacy against clinical advanced NSCLC.

GSH-responsive Pt-based nanomotor with improved doxorubicin delivery for synergistic osteosarcoma chemotherapy

Osteosarcoma (OS), a highly malignant primary tumor, poses significant threats. Chemotherapy remains the main treatment approach but is limited by low drug bioavailability, poor permeability, and notable side effects. Herein, a near-infrared light (NIR)-driven and GSH-responsive poly(ethylene glycol)-SS-polystyrene-doxorubicin and platinum nanoparticles (PSPDP) nanomotor, wherein disulfide bonds served as GSH sponsors and platinum nanoparticles as producers of reactive oxygen species (ROS) to induce cell apoptosis, combined with NIR-driven propulsion to enhance the inhibitory effect of encapsulated doxorubicin (DOX). The results demonstrated that the PSPDP nanomotor can be effectively driven due to its good photothermal properties, with its movement speed increased 2.10 times under NIR laser exposure. Additionally, the efficiency of DOX release increased with the increase in GSH concentration, demonstrating favorable GSH responsiveness. Pt-NPs also exhibited good photothermal properties, enabling self-thermophoresis to drive. Minimal cytotoxic effects of PSPDP were observed on a series of cell lines compared with DOX solution and Pt-NPs. Notably, the Pt-NPs generated a significant amount of ROS, synergistically enhancing the therapeutic effect of DOX, as evidenced by a 5.53-fold increase in OS cell growth inhibition and evident osteosarcoma growth inhibition in the nude mice model. Thus, the NIR-driven, localized, and low-toxic nanomotor may offer a promising therapeutic strategy for OS intervention. STATEMENT OF SIGNIFICANCE: Enhancing drug penetration efficiency and developing delivery systems that respond to the tumor microenvironment to release drugs are effective strategies for treating osteosarcoma (OS). Here, a near-infrared (NIR) light-driven and glutathione (GSH)-responsive nanomotor, integrating poly(ethylene glycol)-SS-polystyrene-doxorubicin and platinum nanoparticles (PSPDP), was produced and used for OS treatment. This PSPDP nanomotor exhibits significant advancements in photothermal activation and self-thermophoresis, enabling a 2.10-fold increase in movement speed under NIR exposure. Such enhanced motility improves the localized delivery and controlled release of doxorubicin, thus increasing drug bioavailability and minimizing systemic toxicity. Additionally, the nanomotor's ability to generate reactive oxygen species significantly amplifies its therapeutic impact, evidenced by a remarkable 5.53-fold increase in tumor growth inhibition. These features make the PSPDP nanomotor a promising candidate for effective and targeted OS treatment strategies.

Design strategies and biomedical applications of organic NIR-IIb fluorophores

The introduction of fluorescence imaging (FLI) in near-infrared II sub-channels (NIR-IIb, 1500-1700 nm) has revolutionized the ability to explore complex patho-physiological settings in vivo. Despite the transformative potentials, the development of organic NIR IIb dyes encounters considerable difficulties, and only a limited number of such fluorophores have been developed so far. This review systematically introduces design strategies of organic NIR-IIb fluorophores classified by molecular scaffolds, mainly including cyanine dyes and D-A-D small molecule dyes. The design strategies of cyanine dyes involve repurposing of the existing NIR dyes, conjugate reinforcement and regulation of the aggregation state. For D-A-D small molecule dyes, strategies mainly incorporate the extension of the conjugate skeleton, introduction of shielding units, and acceptor/donor engineering. We further describe recent biomedical applications including biomedical imaging and imaging-guided therapy, and conclude by clarifying the current challenges and prospects of NIR-IIb FLI.

AlbiCDN: albumin-binding amphiphilic STING agonists augment the immune activity for cancer immunotherapy

The stimulator of interferon genes (STING) has been an attractive target in cancer immunotherapy. However, natural ligand cyclic dinucleotides (CDNs) and CDN derivatives have demonstrated limited efficacy in clinical trials. This limitation stems from the inherent structure of CDNs, which leads to enzymatic degradation, poor cell internalisation, rapid clearance from the tumour microenvironment, and dose-limiting toxicity. In this study, we developed an amphipathic STING agonist, termed albumin-binding CDNs (AlbiCDNs), to enhance the efficacy of c-di-GMP (CDG) via a lipid-conjugated strategy. The lipid provided a platform for albumin hitchhiking, which facilitated the cytoplasmic delivery of CDG without the use of any exogenous components. In addition, incorporating a stimuli-responsive lipid motif further enhanced the cellular release of CDG. Our results indicated that CDG-1C14, an AlbiCDN, efficiently stimulated the maturation and activation of antigen-presenting cells through STING activation. Furthermore, CDG-1C14 exhibited a significant inhibitory effect on the tumour therapeutic model. Therefore, AlbiCDN is a potent platform for cancer immunotherapy that can expedite clinical translation.

Effects of Lipid Headgroups on the Mechanical Properties and In Vitro Cellular Internalization of Liposomes

We performed all-atom and coarse-grained simulations of lipid bilayer mixtures of the unsaturated lipid DOPC, with saturated lipids having the same 18-carbon acyl tails and different headgroups, to understand their mechanical properties. The secondary lipids were DSPG, DSPA, DSPS, DSPC, and DSPE. The DOPC:DSPG system with 65:35 molar ratio was the softest, with area compressibility modulus KA ∼ 22% smaller than the pure DOPC value. Raising the mole % of DOPC leads to increases in KA, yet at any given composition the KA trend is DSPG < DSPA < DSPS < DSPC < DSPE. Lipid-lipid interactions are weaker in DOPC:DSPG mixtures and stronger in DSPE systems. The head and phosphate groups of the secondary lipids DSPG, DSPA, and DSPS interact strongly with salt ions. Adding secondary lipids leads to DOPC having more ordered acyl tails relative to pure DOPC systems. No evidence of phase separation or inhomogeneities was observed in our simulations. We synthesized three liposomal formulations, L-DOPC (pure DOPC) and L-DOPC/DSPG and L-DOPC/DSPA, both with 15 mol % of secondary lipid. L-DOPC/DSPA had approximately 3- and 2-times higher in vitro internalization by normal epithelial (EpH4-Ev) and metastatic breast cancer (4T1) cells, compared with L-DOPC. The uptake of L-DOPC/DSPG by EpH4-Ev cells was almost 2-fold compared to L-DOPC, but both liposomes had similar uptakes by cancer cells. As L-DOPC/DSPG and L-DOPC/DSPA have similar KA values, we presumed that the mechanical properties, possibly in combination with the higher negative surface charges in L-DOPC/DSPA and differences in effective liposome diameters and diffusivities, contributed to these observations.

Regioisomerism in NIR-II-emissive semiconducting biradicals for high-performance bioimaging and phototheranostics of tumors

Photothermal agents (PTAs) have received significant attention in medical therapeutic and diagnostic applications. Despite their tremendous development, developing PTAs is challenging when applied to a living body with deep tissue, as it usually leads to attenuated therapeutic efficiency and potential biosafety hazards. Here, we report a molecular isomerization strategy based on NIR-II semiconducting biradicals that boosts the performance of NIR-II phototheranostics. With a stereoisomeric design by precisely manipulating the substitution position of the alkyl side chain, the optimal isomer, α-TBTS, and its nanoparticles (NPs) provide enhanced NIR-II absorption and 63% photothermal conversion capabilities, resulting in efficient photoablation of tumor cells. Most importantly, the relationship between the molecular isomerism of these NIR-II theranostics enables enhanced NIR-II performance, which has been proven by theoretical and ultrafast spectroscopy studies. With all these advantages, the α-TBTS nanoplatform has simultaneously achieved high-resolution whole-body NIR-II angiography and trimodal tumor-targeted imaging in vivo. Moreover, α-TBTS NPs efficiently inhibited tumor growth without recurrence upon NIR-II light irradiation, providing good biosafety. This work demonstrates the feasibility of molecular isomerization in multimodal NIR-II biradical PTAs and thus provides a suitable theranostic agent for high-performance tumor phototheranostics.

Bioengineering stimuli-responsive organic-inorganic nanoarchitetures based on carboxymethylcellulose-poly-l-lysine nanoplexes: Unlocking the potential for bioimaging and multimodal chemodynamic-magnetothermal therapy of brain cancer cells

Regrettably, glioblastoma multiforme (GBM) remains the deadliest form of brain cancer, where the early diagnosis plays a pivotal role in the patient's therapy and prognosis. Hence, we report for the first time the design, synthesis, and characterization of new hybrid organic-inorganic stimuli-responsive nanoplexes (NPX) for bioimaging and killing brain cancer cells (GBM, U-87). These nanoplexes were built through coupling two nanoconjugates, produced using a facile, sustainable, green aqueous colloidal process ("bottom-up"). One nanocomponent was based on cationic epsilon-poly-l-lysine polypeptide (εPL) conjugated with ZnS quantum dots (QDs) acting as chemical ligand and cell-penetrating peptide (CPP) for bioimaging of cancer cells (QD@εPL). The second nanocomponent was based on anionic carboxymethylcellulose (CMC) polysaccharide surrounding superparamagnetic magnetite "nanozymes" (MNZ) behaving as a capping macromolecular shell (MNZ@CMC) for killing cancer cells through chemodynamic therapy (CDT) and magnetohyperthermia (MHT). The results demonstrated the effective production of supramolecular aqueous colloidal nanoplexes (QD@εPL_MNZ@CMC, NPX) integrated into single nanoplatforms, mainly electrostatically stabilized by εPL/CMC biomolecules with anticancer activity against U-87 cells using 2D and 3D spheroid models. They displayed nanotheranostics (i.e., diagnosis and therapy) behavior credited to the photonic activity of QD@εPL with luminescent intracellular bioimaging, amalgamated with a dual-mode killing effect of GBM cancer cells through CDT by nanozyme-induced biocatalysis and as "nanoheaters" by magnetically-responsive hyperthermia therapy.

Modulating active targeting nanoparticle design according to tumor progressions

Targeting drug delivery systems mediated by nanoparticles has shown great potential in the diagnosis and treatment of cancer. However, influences of different tumor progressions on the accumulation of nanoparticles, especially the ligand-modified active targeting nanoparticles are seldom exploited. In this work, the accumulation and penetration of RGD-modified gold nanoparticles (active AuNPs) with different sizes were investigated in orthotopic breast cancer with different tumor progressions. The results showed that the smallest active AuNPs had better accumulation and permeation effects in early tumor tissues with the relatively looser extracellular matrix, larger gaps, lower interstitial fluid pressure, and less receptor expression, which was due to size effects. However, the larger active AuNPs had better accumulation and penetration effects in late tumor tissues with highly expressed target receptors integrin α v β 3 because of the multivalent interactions between larger active nanoparticles and integrin α v β 3. In the midterm, tumor accumulation of active AuNPs was equally influenced by size effects and multivalent interactions. Therefore, RGD-modified nanoparticles with sizes of 7 and 90 nm accumulated more in tumors. This study will guide a rational design of active targeting nanoparticles for enhancing the diagnosis and treatment of tumors based on their progressions.

Triphenylphosphine-modified cyclometalated iridiumIII complexes as mitochondria-targeting anticancer agents with enhanced selectivity

This study presents the development and evaluation of triphenylphosphine-modified cyclometalated iridiumIII complexes as selective anticancer agents targeting mitochondria. By leveraging the mitochondrial localization capability of the triphenylphosphine group, these complexes displayed promising cytotoxicity in the micromolar range (3.12-7.24 μM) against A549 and HeLa cancer cells, these complexes exhibit significantly higher activity compared to their unmodified counterparts lacking the triphenylphosphine moiety. Moreover, they demonstrate improved specificity for cancer cells over normal cells, achieving selectivity index in the range of 5.46-14.83. Mechanistic studies confirmed that these complexes selectively target mitochondria rather than DNA, as shown by confocal microscopy and flow cytometry, where they accumulate to induce mitochondrial dysfunction. This disruption leads to mitochondrial membrane depolarization (MMP), elevated reactive oxygen species (ROS) levels, and activation of intrinsic apoptosis pathways. Furthermore, the complexes induce cell cycle arrest at the G2/M phase and suppress the migration of A549 cells.

Surface Functionalization of Nanocarriers with Anti-EGFR Ligands for Cancer Active Targeting

Active cancer targeting consists of the selective recognition of overexpressed biomarkers on cancer cell surfaces or within the tumor microenvironment, enabled by ligands conjugated to drug carriers. Nanoparticle (NP)-based systems are highly relevant for such an approach due to their large surface area which is amenable to a variety of chemical modifications. Over the past decades, several studies have debated the efficiency of passive targeting, highlighting active targeting as a more specific and selective approach. The choice of conjugation chemistry for attaching ligands to nanocarriers is critical to ensure a stable and robust system. Among the panel of cancer biomarkers, the epidermal growth factor receptor (EGFR) stands as one of the most frequently overexpressed receptors in different cancer types. The design and development of nanocarriers with surface-bound anti-EGFR ligands are vital for targeted therapy, relying on their facilitated capture by EGFR-overexpressing tumor cells and enabling receptor-mediated endocytosis to improve drug accumulation within the tumor microenvironment. In this review, we examine several examples of the most recent and significant anti-EGFR nanocarriers and explore the various conjugation strategies for NP functionalization with anti-EGFR biomolecules and small molecular ligands. In addition, we also describe some of the most common characterization techniques to confirm and analyze the conjugation patterns.

The mechanism underlying metastasis in triple-negative breast cancer: focusing on the interplay between ferroptosis, epithelial-mesenchymal transition, and non-coding RNAs

Triple-negative breast cancer (TNBC) is a type of breast cancer with lack the expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). It is the most aggressive breast cancer and the most difficult to treat due to its poor response to treatments and extremely invasive characteristics. The typical treatment for TNBC frequently results in relapse because of the lack of particular treatment choices. It is urgent to focus on identifying a workable and effective target for the treatment of TNBC. Cancer metastasis is significantly influenced by epithelial-mesenchymal transition (EMT). Ferroptosis is an iron-dependent cell death form, and changes its key factor to affect the proliferation and metastasis of TNBC. Several reports have established associations between EMT and ferroptosis in TNBC metastasis. Furthermore, non-coding RNA (ncRNA), which has been previously described, can also control cancer cell death and metastasis. Thus, in this review, we summarize the correlation and pathways among the ferroptosis, EMT, and ncRNAs in TNBC metastasis. Also, aim to find out a novel strategy for TNBC treatment through the ncRNA-ferroptosis-EMT axis.

Finely Tailored Conjugated Small Molecular Nanoparticles for Near-Infrared Biomedical Applications

Near-infrared (NIR) phototheranostics (PTs) show higher tissue penetration depth, signal-to-noise ratio, and better biosafety than PTs in the ultraviolet and visible regions. However, their further advancement is severely hindered by poor performances and short-wavelength absorptions/emissions of PT agents. Among reported PT agents, conjugated small molecular nanoparticles (CSMNs) prepared from D-A-typed photoactive conjugated small molecules (CSMs) have greatly mediated this deadlock by their high photostability, distinct chemical structure, tunable absorption, intrinsic multifunctionality, and favorable biocompatibility, which endows CSMNs with more possibilities in biological applications. This review aims to introduce the recent progress of CSMNs for NIR imaging, therapy, and synergistic PTs with a comprehensive summary of their molecular structures, structure types, and optical properties. Moreover, the working principles of CSMNs are illustrated from photophysical and photochemical mechanisms and light-tissue interactions. In addition, molecular engineering and nanomodulation approaches of CSMs are discussed, with an emphasis on strategies for improving performances and extending absorption and emission wavelengths to the NIR range. Furthermore, the in vivo investigation of CSMNs is illustrated with solid examples from imaging in different scenarios, therapy in 2 modes, and synergistic PTs in combinational functionalities. This review concludes with a brief conclusion, current challenges, and future outlook of CSMNs.

Efficient Cytosolic Delivery of Single-Chain Polymeric Artificial Enzymes for Intracellular Catalysis and Chemo-Dynamic Therapy

Designing artificial enzymes for in vivo catalysis presents a great challenge due to biomacromolecule contamination, poor biodistribution, and insufficient substrate interaction. Herein, we developed single-chain polymeric nanoparticles with Cu/N-heterocyclic carbene active sites (SCNP-Cu) to function as peroxidase mimics for in vivo catalysis and chemo-dynamic therapy (CDT). Compared with the enzyme mimics based on unfolded linear polymer scaffold and multichain cross-linked scaffold, SCNP-Cu exhibits improved tumor accumulation and CDT efficiency both in vitro and in vivo. Protein-like size of the SCNP scaffold promotes passive diffusion, whereas positive surface charge allows its active transcytosis for deep tumor penetration and hence accumulation in the tumor site. The submolecular compartments of the SCNP scaffold effectively protect the active sites from protein bindings, thereby providing a "cleaner" microenvironment for catalysis within a living system. The folded structure of SCNP-Cu facilitates their cytosolic delivery of and free diffusion within cytosol, ensuring efficient contact with endogenous H2O2, in situ generation of toxic hydroxyl radicals (·OH), and effective damage of intracellular targets (i.e., lipids, nucleic acids). This work establishes versatile SCNP-based nanoplatforms for developing artificial enzymes for in vivo catalysis.

Phthalocyanine aggregates as semiconductor-like photocatalysts for hypoxic-tumor photodynamic immunotherapy

Photodynamic immunotherapy (PIT) has emerged as a promising approach for efficient eradication of primary tumors and inhibition of tumor metastasis. However, most of photosensitizers (PSs) for PIT exhibit notable oxygen dependence. Herein, a concept emphasizing on transition from molecular PSs into semiconductor-like photocatalysts is proposed, which converts the PSs from type II photoreaction to efficient type I photoreaction. Detailed mechanism studies reveal that the nanostructured phthalocyanine aggregate (NanoNMe) generates radical ion pairs through a photoinduced symmetry breaking charge separation process, achieving charge separation through a self-substrate approach and leading to exceptional photocatalytic charge transfer activity. Additionally, a reformed phthalocyanine aggregate (NanoNMO) is fabricated to improve the stability in physiological environments. NanoNMO showcases significant photocytotoxicities under both normoxic and hypoxic conditions and exhibits remarkable tumor targeting ability. Notably, the NanoNMO-based photodynamic therapy and PD-1 checkpoint inhibitor-based immunotherapy synergistically triggers the infiltration of cytotoxic T lymphocytes into the tumor sites of female mice, leading to the effective inhibition of breast tumor growth.

Multi-Chambered Core/Shell Supraparticles for Real-Time, Full-Time Diagnosis and Treatment Integration of Tumors

To a certain extent, theranostic nanoplatforms promote tumor treatment efficiency. However, timely monitoring of the critical stages and signal sustainability of the entire process is challenging. In this study, multi-chambered core/shell magnetic nanoparticles (MC-MNPs) as drug and imaging agent multi-loaded nanocarriers with a synergistic release function are reported. Supraparticles with stable chambers are formed by the supercooling self-assembly of several core/shell magnetic nanoparticles composed of amphiphilic copolymers as the core and hydrophilic magnetic iron oxide nanoparticles as the shell. Desalinized doxorubicin and coumarin 6 are stored in different cavities of nanocarriers, and chitosan is used as an outer encapsulation layer. Based on their construction properties, MC-MNPs can exhibit gradient-degraded and steady-released controllability in the tumor environment. Furthermore, real-time accumulation situations and full-time diagnostic signals of nanocarriers are thoroughly demonstrated using fluorescence imaging and T2-weighted magnetic resonance imaging before and after magnetic hyperthermia in targeted tumors under an alternating magnetic field. Thus, MC-MNPs as theranostic nanocarriers exhibit great potential for the timely monitoring and full-time guidance of tumor treatment.

Prenatal Silicon Dioxide Nanoparticles Exposure Reduces Female Offspring Fertility Without Affecting Males

Silicon dioxide nanoparticles (SiO2 NPs) are widely utilized in biomedicine due to their controllable size and biocompatibility. While previous studies have demonstrated that prenatal exposure to SiO2 NPs can traverse the placental barrier and induce neurotoxicity in offspring. However, their reproductive toxicity remains unclear. Here, it is found that prenatal SiO2 NPs exposure led to subfertility in female offspring, evidenced by decreased ovulation potential, ovarian reserve, and litter size. In contrast, male offspring maintained normal sperm production and fertility. Mechanistic analyses revealed that prenatal SiO2 NPs exposure disrupted meiotic recombination and increased oocyte apoptosis, resulting in reduced postnatal primordial follicle formation in females. Conversely, meiotic recombination occurring postnatally in male offspring remained unaffected. Notably, treatment with carboxylate (COOH)-functionalized SiO2 nanoparticles (SiO2-COOH NPs) has a minimal impact on fertility in female offspring. Further research, including clinical studies, is needed to confirm these findings in humans. These findings demonstrated gender-specific reproductive toxicity induced by prenatal SiO2 NPs exposure and highlighted the importance of considering nanoparticle safety in prenatal contexts.

Nanotherapeutics for Macrophage Network Modulation in Tumor Microenvironments: Targets and Tools

Macrophage is an important component in the tumor immune microenvironment, which exerts significant influence on tumor development and metastasis. Due to their dual nature of promoting and suppressing inflammation, macrophages can serve as both targets for tumor immunotherapy and tools for treating malignancies. However, the abundant infiltration of tumor-associated macrophages dominated by an immunosuppressive phenotype maintains a pro-tumor microenvironment, and engineering macrophages using nanotechnology to manipulate the tumor immune microenvironment represent a feasible approach for cancer immunotherapy. Additionally, considering the phagocytic and specifically tumor-targeting capabilities of M1 macrophages, macrophages manipulated through cellular engineering and nanotechnology, as well as macrophage-derived exosomes and macrophage membranes, can also become effective tools for cancer treatment. In conclusion, nanotherapeutics targeting macrophages remains immense potential for the development of macrophage-mediated tumor treatment methods and will further enhance our understanding, diagnosis, and treatment of various malignants.

Impact of inner hydrophobicity of dendrimer nanomicelles on biodistribution: a PET imaging study

Self-assembly is a powerful strategy for building nanosystems for biomedical applications. We have recently developed small amphiphilic dendrimers capable of self-assembling into nanomicelles for tumor imaging. In this context, we studied the impact of increased hydrophobicity of the amphiphilic dendrimer on hydrophilic/hydrophobic balance and consequently on the self-assembly and subsequent biodistribution. Remarkably, despite maintaining the exact same surface chemistry, similar zeta potential, and small size, the altered and enlarged hydrophobic component within the amphiphilic dendrimer led to enhanced stability of the self-assembled nanomicelles, with prolonged circulation time and massive accumulation in the liver. This study reveals that even structural alteration within the interior of nanomicelles can dramatically impact biodistribution profiles. This finding highlights the deeper complexity of rational design for nanomedicine and the need to consider factors other than surface charge and chemistry, as well as size, all of which significantly impact the biodistribution of self-assembling nanosystems.

A new era of cancer phototherapy: mechanisms and applications

The past decades have witnessed great strides in phototherapy as an experimental option or regulation-approved treatment in numerous cancer indications. Of particular interest is nanoscale photosensitizer-based phototherapy, which has been established as a prominent candidate for advanced tumor treatment by virtue of its high efficacy and safety. Despite considerable research progress on materials, methods and devices in nanoscale photosensitizing agent-based phototherapy, their mechanisms of action are not always clear, which impedes their practical application in cancer treatment. Hence, from a new perspective, this review elaborates the working mechanisms, involving impairment and moderation effects, of diverse phototherapies on cells, organelles, organs, and tissues. Furthermore, the most current available phototherapy modalities are categorized as photodynamic, photothermal, photo-immune, photo-gas, and radio therapies in this review. A comprehensive understanding of the inferiority and superiority of various phototherapies will facilitate the advent of a new era of cancer phototherapy.

Designing nanotheranostics with machine learning

The inherent limits of traditional diagnoses and therapies have driven the development and application of emerging nanotechnologies for more effective and safer management of diseases, herein referred to as 'nanotheranostics'. Although many important technological successes have been achieved in this field, widespread adoption of nanotheranostics as a new paradigm is hindered by specific obstacles, including time-consuming synthesis of nanoparticles, incomplete understanding of nano-bio interactions, and challenges regarding chemistry, manufacturing and the controls required for clinical translation and commercialization. As a key branch of artificial intelligence, machine learning (ML) provides a set of tools capable of performing time-consuming and result-perception tasks, thus offering unique opportunities for nanotheranostics. This Review summarizes the progress and challenges in this emerging field of ML-aided nanotheranostics, and discusses the opportunities in developing next-generation nanotheranostics with reliable datasets and advanced ML models to offer better clinical benefits to patients.

NIR-II Fluorescent Nanotheranostics with a Switchable Irradiation Mode for Immunogenic Sonodynamic Therapy

Nanotheranostics, which integrate diagnostic and therapeutic functionalities, offer significant potential for tumor treatment. However, current nanotheranostic systems typically involve multiple molecules, each providing a singular diagnostic or therapeutic function, leading to challenges such as complex structural composition, poor targeting efficiency, lack of spatiotemporal control, and dependence on a single therapeutic modality. This study introduces NPRBOXA, a nanoparticle functionalized with surface-bound cRGD for targeted delivery to αvβ3/αvβ5 receptors on tumor cells, achieving theranostic integration by sequentially switching its irradiation modes. Under 808 nm laser irradiation, NPRBOXA emits NIR-II fluorescence, which aids in identifying the nanoparticle's location and fluorescence intensity, thereby determining the optimal treatment window. Following this, the irradiation mode switches to ultrasound irradiation at the optimal treatment window. Ultrasound irradiation induces NPRBOXA to generate reactive oxygen species, promoting the reduction of OXA-IV to OXA-II, which in turn triggers immunogenic cell death. This mechanism enables a combination of sonodynamic therapy, chemotherapy, and immunotherapy for tumor treatment. The versatile design of NPRBOXA holds promise for advancing precision oncology through enhanced therapeutic efficacy and real-time imaging guidance.

Omics-Enhanced Nanomedicine for Cancer Therapy

Cancer nanomedicine has emerged as a promising approach to overcome the limitations of conventional cancer therapies, offering enhanced efficacy and safety in cancer management. However, the inherent heterogeneity of tumors presents increasing challenges for the application of cancer nanomedicine in both diagnosis and treatment. This heterogeneity necessitates the integration of advanced and high-throughput analytical techniques to tailor nanomedicine strategies to individual tumor profiles. Omics technologies, encompassing genomics, epigenomics, transcriptomics, proteomics, metabolomics, and more, provide unparalleled insights into the molecular and cellular mechanisms underlying cancer. By dissecting tumor heterogeneity across multiple levels, these technologies offer robust support for the development of personalized and precise cancer nanomedicine strategies. In this review, the principles, techniques, and applications of key omics technologies are summarized. Especially, the synergistic integration of omics and nanomedicine in cancer therapy is explored, focusing on enhanced diagnostic accuracy, optimized therapeutic strategies and the assessment of nanomedicine-mediated biological responses. Moreover, this review addresses current challenges and outlines future directions in the field of omics-enhanced nanomedicine. By offering valuable insights and guidance, this review aims to advance the integration of omics with nanomedicine, ultimately driving improved diagnostic and therapeutic strategies for cancer.

Nanotechnology in healthcare, and its safety and environmental risks

Nanotechnology holds immense promise in revolutionising healthcare, offering unprecedented opportunities in diagnostics, drug delivery, cancer therapy, and combating infectious diseases. This review explores the multifaceted landscape of nanotechnology in healthcare while addressing the critical aspects of safety and environmental risks associated with its widespread application. Beginning with an introduction to the integration of nanotechnology in healthcare, we first delved into its categorisation and various materials employed, setting the stage for a comprehensive understanding of its potential. We then proceeded to elucidate the diverse healthcare applications of nanotechnology, spanning medical diagnostics, tissue engineering, targeted drug delivery, gene delivery, cancer therapy, and the development of antimicrobial agents. The discussion extended to the current situation surrounding the clinical translation and commercialisation of these cutting-edge technologies, focusing on the nanotechnology-based healthcare products that have been approved globally to date. We also discussed the safety considerations of nanomaterials, both in terms of human health and environmental impact. We presented the in vivo health risks associated with nanomaterial exposure, in relation with transport mechanisms, oxidative stress, and physical interactions. Moreover, we highlighted the environmental risks, acknowledging the potential implications on ecosystems and biodiversity. Lastly, we strived to offer insights into the current regulatory landscape governing nanotechnology in healthcare across different regions globally. By synthesising these diverse perspectives, we underscore the imperative of balancing innovation with safety and environmental stewardship, while charting a path forward for the responsible integration of nanotechnology in healthcare.

Integrin-Specific Stimuli-Responsive Nanomaterials for Cancer Theranostics

Background: Cancer is one of the leading causes of death worldwide. The tumor microenvironment makes the tumor difficult to treat, favoring drug resistance and the formation of metastases, resulting in death. Methods: Stimuli-responsive nanoparticles have shown great capacity to be used as a powerful strategy for cancer treatment, diagnostic, as well as theranostic. Nanocarriers are not only able to respond to internal stimuli such as oxidative stress, weakly acidic pH, high temperature, and the high expression of particular enzymes, but also to external stimuli such as light and paramagnetic characteristics to be exploited. Results: In this work, stimulus-responsive nanocarriers functionalized with arginine-glycine-aspartic acid (Arg-Gly-Asp) sequence as well as mimetic sequences with the capability to recognize integrin receptors are analyzed. Conclusions: This review highlights the progress that has been made in the development of new nanocarriers, capable of responding to endogenous and exogenous stimuli essential to combat cancer.

Polymer-drug conjugates: revolutionizing nanotheranostic agents for diagnosis and therapy

Nanotheranostics, an amalgamation of therapeutic and diagnostic capabilities at the nanoscale, is revolutionizing personalized medicine. Polymer-drug conjugates (PDCs) stand at the forefront of this arena, offering a multifaceted approach to treat complex diseases such as cancer. This review explores the recent advancements in PDCs, highlighting their design principles, working mechanisms, and the therapeutic applications. We discuss the incorporation of imaging agents into PDCs that allow for real-time monitoring of drug delivery and treatment efficacy. With the aim of improving patient care, the review examines how PDCs enable targeted drug delivery, minimize side effects, and provide valuable diagnostic data, hence enhancing the precision of medical interventions. We also address the challenges facing the clinical translation of PDCs, such as scalability, regulatory hurdles, and cost-effectiveness, providing a comprehensive outlook on the future of nanotheranostics in patient management.

Hybrid Homodimeric Prodrug Nanoassemblies for Low-Toxicity and Synergistic Chemophotodynamic Therapy of Melanoma

Synergistically active nanoparticles hold great promise for facilitating multimodal cancer therapy. However, strategies for their feasible manufacture and optimizing their formulations remain lacking. Herein, we developed hybrid homodimeric prodrug nanotherapeutics with tumor-restricted drug activation and chemophotodynamic pharmacology by leveraging the supramolecular nanoassembly of small molecules. The covalent dimerization of cytotoxic taxane chemotherapy via reactive oxygen species (ROS)-activated linker yielded a homodimeric prodrug, which was further coassembled with a ROS-generating dimeric photosensitizer. The nanoassemblies were readily refined in an amphiphilic PEGylation matrix for particle surface cloaking and in vivo intravenous injection. The nanoassemblies were optimized with favorable stability and combinatorial synergism to kill cancer cells. Upon near-infrared laser irradiation, the neighboring dimer photosensitizer generated ROS, subsequently triggering bond cleavage to facilitate drug activation, which in turn produced synergistic chemophotodynamic effects against cancer. In a preclinical model of melanoma, the intravenous administration of PEGylated nanoassemblies followed by near-infrared tumor irradiation led to significant tumor regression. Furthermore, animals treated with this efficient, photo-activatable nanotherapy exhibited low systemic toxicity even at high doses. This study describes a simple and cost-effective approach to integrate multimodal therapies by creating self-assembling small-molecule prodrugs for designing a combinatorial therapeutic nanosystem. We consider that this new paradigm holds substantial potential for advancing clinical translation.

Dual pH-responsive polypeptide nanoprobes for lysosomes enhanced bioimaging and tumor photothermal therapy under 1064 nm irradiation

Cancer cell precise fluorescence imaging and following tumor photothermal therapy have garnered ongoing interest. Lysosomes in cancer cells in a typical acidic environment can be used for smart bioimaging, and intelligent NIR-II fluorescence probes are attractive for tumor phototheranostics. Here, we successfully synthesized a pH-responsive NIR-II fluorescent dye FPZ and the introduction of N-methylpiperazine moiety at the ring position in the dye-endowed FPZ with fluorescence enhancement under acidic response. A pH-sensitive amphiphilic polypeptide was selected as the carrier to prepare FPZ-PN nanoparticles, which could be disassembled under acidic stimulation for efficient drug delivery and enrichment, and its fluorescence was significantly restored and enhanced (fluorescence enhancement of about 4.2 times) because of the blockage of the photoinduced electron transfer process, which allowed for efficient NIR-II fluorescence imaging, especially the lysosomes in cancer cells. In addition, the nanoparticles exhibited great photostability and a significant photothermal effect, with a photothermal conversion efficiency reaching as high as 69.96 % when subjected to a 1064 nm laser irradiation, which can effectively kill tumor cells. Thus, this work provides a new effective strategy for designing smart-responsive nanomedicine systems for precise localization and tumor elimination.

Assembly-enhanced indocyanine green nanoparticles for fluorescence imaging-guided photothermal therapy

The development of theranostic agents that offer complete biocompatibility, coupled with enhanced diagnostic and therapeutic performance, is crucial for fluorescence imaging-guided photothermal therapy in anti-tumor applications. However, the fabrication of nanotheranostics meeting the aforementioned requirements is challenged by concerns regarding biosafety and limited control over construction. Herein, we reported a class of fluorescence imaging-guided photothermal theranostic nanomaterials that are composed of amino acid derivatives and clinically used small photoactive indocyanine green molecules. Through manipulation of noncovalent interactions, these binary building blocks can co-assemble into nanoparticles in a tunable manner. Significantly, such construction not only maintained the fluorescence properties of photoactive molecules, but also enhanced their stability to overcome barriers from photodegradation and complex physiological conditions. These collective features integrated their precise anti-tumor applications, including fluorescence imaging diagnosis and photothermal ablation therapy. This study reported a class of nanotheranostics characterized by biocompatibility, adjustable construction, and robust stability, which are beneficial for the clinical translation of fluorescence imaging-guided photothermal therapy against tumors.

Gold-siRNA supraclusters enhance the anti-tumor immune response of stereotactic ablative radiotherapy at primary and metastatic tumors

Strategies to enhance the anti-tumor immune response of stereotactic ablative radiotherapy (SABR) at primary tumors and abscopal sites are under intensive investigation. Here we report a metabolizable binary supracluster (BSCgal) that combines gold nanoclusters as radiosensitizing adjuvants with small interfering RNA (siRNA) targeting the immunosuppressive mediator galectin-1 (Gal-1). BSCgal comprises reversibly crosslinked cationic gold nanoclusters and siRNA complexes in a polymer matrix that biodegrades over weeks, facilitating clearance (90.3% in vivo clearance at 4 weeks) to reduce toxicity. The particle size well above the renal filtration threshold facilitates passive delivery to tumors. Using mouse models of head and neck cancer, we show that BSCgal augments the radiodynamic and immunotherapeutic effects of SABR at the primary and metastatic tumors by promoting tumor-inhibitory leukocytes, upregulating cytotoxic granzyme B and reducing immunosuppressive cell populations. It outperforms SABR plus Gal-1 antagonists, chemoradiation drug cisplatin or PD-1 inhibitor. This work presents a translatable strategy to converge focal radiosensitization with targeted immune checkpoint silencing for personalized radioimmunotherapy.

Carrier-Free Nanoagent Interfering with Cancer-Associated Fibroblasts' Metabolism to Promote Tumor Penetration for Boosted Chemotherapy

Elevated production of extracellular matrix (ECM) in tumor stroma is a critical obstacle for drug penetration. Here we demonstrate that ATP-citrate lyase (ACLY) is significantly upregulated in cancer-associated fibroblasts (CAFs) to produce tumor ECM. Using a self-assembling nanoparticle-design approach, a carrier-free nanoagent (CFNA) is fabricated by simply assembling NDI-091143, a specific ACLY inhibitor, and doxorubicin (DOX) or paclitaxel (PTX), the first-line chemotherapeutic drug, via multiple noncovalent interactions. After arriving at the CAFs-rich tumor site, NDI-091143-mediated ACLY inhibition in CAFs can block the de novo synthesis of fatty acid, thereby dampening the fatty acid-involved energy metabolic process. As the lack of enough energy, the energetic CAFs will be in a dispirited state that is unable to produce abundant ECM, thereby significantly improving drug perfusion in tumors and enhancing the efficacy of chemotherapy. Such a simple drug assembling strategy aimed at CAFs' ACLY-mediated metabolism pathway presents the feasibility of stromal matrix reduction to potentiate chemotherapy.

Core-Shell Microspheres with Encapsulated Gold Nanoparticle Carriers for Controlled Release of Anti-Cancer Drugs

Cancer is one of the major threats to human health and lives. However, effective cancer treatments remain a great challenge in clinical medicine. As a common approach for cancer treatment, chemotherapy has saved the life of millions of people; however, patients who have gone through chemotherapy often suffer from severe side effects owing to the inherent cytotoxicity of anti-cancer drugs. Stabilizing the blood concentration of an anti-cancer drug will reduce the occurrence or severity of side effects, and relies on using an appropriate drug delivery system (DDS) for achieving sustained or even on-demand drug delivery. However, this is still an unmet clinical challenge since the mainstay of anti-cancer drugs is small molecules, which tend to be diffused rapidly in the body, and conventional DDSs exhibit the burst release phenomenon. Here, we establish a class of DDSs based on biodegradable core-shell microspheres with encapsulated doxorubicin hydrochloride-loaded gold nanoparticles (DOX@Au@MSs), with the core-shell microspheres being made of poly(lactic-co-glycolic acid) in the current study. By harnessing the physical barrier of the biodegradable shell of core-shell microspheres, DOX@Au@MSs can provide a sustained release of the anti-cancer drug in the test duration (which is 21 days in the current study). Thanks to the photothermal properties of the encapsulated gold nanoparticle carriers, the core-shell biodegradable microspheres can be ruptured through remotely controlled near-infrared (NIR) light, thereby achieving an NIR-controlled triggered release of the anti-cancer drug. Furthermore, the route of the DOX-Au@MS-enabled controlled release of the anti-cancer drug can provide durable cancer cell ablation for the long period of 72 h.

Metal ion interference therapy: metal-based nanomaterial-mediated mechanisms and strategies to boost intracellular "ion overload" for cancer treatment

Metal ion interference therapy (MIIT) has emerged as a promising approach in the field of nanomedicine for combatting cancer. With advancements in nanotechnology and tumor targeting-related strategies, sophisticated nanoplatforms have emerged to facilitate efficient MIIT in xenografted mouse models. However, the diverse range of metal ions and the intricacies of cellular metabolism have presented challenges in fully understanding this therapeutic approach, thereby impeding its progress. Thus, to address these issues, various amplification strategies focusing on ionic homeostasis and cancer cell metabolism have been devised to enhance MIIT efficacy. In this review, the remarkable progress in Fe, Cu, Ca, and Zn ion interference nanomedicines and understanding their intrinsic mechanism is summarized with particular emphasis on the types of amplification strategies employed to strengthen MIIT. The aim is to inspire an in-depth understanding of MIIT and provide guidance and ideas for the construction of more powerful nanoplatforms. Finally, the related challenges and prospects of this emerging treatment are discussed to pave the way for the next generation of cancer treatments and achieve the desired efficacy in patients.

Bone-targeting engineered milk-derived extracellular vesicles for MRI-assisted therapy of osteoporosis

The imbalance between osteoblasts and osteoclasts is the cause of osteoporosis. Milk-derived extracellular vesicles (mEVs), excellent drug delivery nanocarriers, can promote bone formation and inhibit bone resorption. In this study, we conjugated bone-targeting peptide (AspSerSer, DSS)6 to mEVs by click chemistry and then loaded with SRT2104, a SIRT1 (silent mating-type information regulation 2 homolog 1) agonist that was proofed to help reduce bone loss. The engineered (DSS)6-mEV-SRT2104 had the intrinsic anti-osteoporosis function of mEVs and SRT2104 to reverse the imbalance in bone homeostasis by simultaneously regulating osteogenesis and osteoclastogenesis. Furthermore, we labelled mEVs with MnB nanoparticles that can be used for the in vivo magnetic resonance imaging (MRI) visualization. The obtained nanocomposites significantly prevented bone loss in osteoporosis mice and increased bone mineral density, exhibiting superior bone accumulation under MRI. We believe the proposed (DSS)6-mEV-SRT2104/MnB provides a novel paradigm for osteoporosis treatment and monitoring.

Fabrication Methods, Structural, Surface Morphology and Biomedical Applications of MXene: A Review

Recently, two-dimensional (2-D) layered materials have revealed outstanding properties and play a crucial role for numerous advanced applications. The emerging transition metal carbides and nitrides, known as MXene with empirical formula Mn+1XnTx, have generated widespread attention and demonstrated impressive potential in various fields. The fabrication of 2-D novel MXene and its composites and their characterizations are applicable to vast applications in different areas such as energy storage, gas sensors, catalysis, and biomedical applications. In this review, the main focus is on the various synthesis methods, their properties, and biomedical applications. This review provides detailed illustrations of MXenes for many biomedical applications, including bioimaging, drug delivery, therapies, biosensors, tissue engineering, and antibacterial reagents. The challenges and future prospects were highlighted in a comprehensive manner, and the existing problems and potential for MXene-based biomaterials were analyzed with the goal of accelerating their use in the biomedical field.

Reversibly photoswitchable protein assemblies with collagen affinity for in vivo photoacoustic imaging of tumors

Recent advancements in photoacoustic (PA) imaging have leveraged reversibly photoswitchable chromophores, known for their dual absorbance states, to enhance imaging sensitivity through differential techniques. Yet, their deployment in tumor imaging has faced obstacles in achieving targeted delivery with high efficiency and specificity. Addressing this challenge, we introduce innovative protein assemblies, DrBphP-CBD, by genetically fusing a photosensory module from Deinococcus radiodurans bacterial phytochrome (DrBphP) with a collagen-binding domain (CBD). These protein assemblies form sub-100-nanometer structures composed of 24 DrBphP dimers and 12 CBD trimers, presenting 24 protein subunits. Their affinity for collagens, combined with impressive photoswitching contrast, markedly improves PA imaging precision. In various tumor models, intravenous administration of DrBphP-CBD has demonstrated enhanced tumor targeting and retention, augmenting contrast in PA imaging by minimizing background noise. This strategy underscores the clinical potential of DrBphP-CBD as PA contrast agents, propelling photoswitchable chromoproteins to the forefront of precise cancer diagnosis.

Croconaine-based NIR-II fluorescence imaging-guided tumor photothermal therapy induces long-term antitumor immune memory

Photothermal therapy (PTT) for cancers guided by optical imaging has recently shown great potential for precise diagnosis and efficient therapy. The second near-infrared window (NIR-II, 1000-1700 nm) fluorescence imaging (FLI) is highly desirable owing to its good spatial and temporal resolution, deep tissue penetration, and negligible tissue toxicity. Organic small molecules are attractive as imaging and treatment agents in biomedical research because of their low toxicity, fast clearance rate, diverse structures, ease of modification, and excellent biocompatibility. Various organic small molecules have been investigated for biomedical applications. However, there are few reports on the use of croconaine dyes (CRs), especially NIR-II emission CRs. To our knowledge, there have been no prior reports of NIR-II emissive small organic photothermal agents (SOPTAs) based on CRs. Herein, we report a croconaine dye (CR-TPE-T)-based nanoparticle (CR NP) with absorption and fluorescence emission in the NIR-I and NIR-II windows, respectively. The CR NPs exhibited intense NIR absorption, outstanding photothermal properties, and good biological compatibility. In vivo studies showed that CR NPs not only achieved real-time, noninvasive NIR-II FLI of tumors, but also induced significant tumor ablation with laser irradiation guided by imaging, without apparent side effects, and promoted the formation of antitumor immune memory in a colorectal cancer model. In addition, the CR NPs displayed efficient inhibition of breast tumor growth, improved longevity of mice and triggered efficient systemic immune responses, which further inhibited tumor metastasis to the lungs. Our study demonstrates the great potential of CRs as therapeutic agents in the NIR-II region for cancer diagnosis.

A review on comprehending immunotherapeutic approaches inducing ferroptosis: Managing tumour immunity

Ferroptosis, a necrotic, iron-dependent controlled cell death mechanism, is distinguished by the development of lipid peroxides to fatal proportions. Malignant tumours, influenced by iron to promote fast development, are vulnerable to ferroptosis. Based upon mounting evidence it has been observed that ferroptosis may be immunogenic and hence may complement immunotherapies. A new approach includes iron oxide-loaded nano-vaccines (IONVs), having supremacy for the traits of the tumour microenvironment (TME) to deliver specific antigens through improving the immunostimulatory capacity by molecular disintegration and reversible covalent bonds that target the tumour cells and induce ferroptosis. Apart from IONVs, another newer approach to induce ferroptosis in tumour cells is through oncolytic virus (OVs). One such oncolytic virus is the Newcastle Disease Virus (NDV), which can only multiply in cancer cells through the p53-SLC7A11-GPX4 pathway that leads to elevated levels of lipid peroxide and intracellular reactive oxygen species leading to the induction of ferroptosis that induce ferritinophagy.

Layer-by-Layer Nanoparticle Assembly for Biomedicine: Mechanisms, Technologies, and Advancement via Acoustofluidics

The deposition of thin films plays a crucial role in surface engineering, tailoring structural modifications, and functionalization across diverse applications. Layer-by-layer self-assembly, a prominent thin-film deposition method, has witnessed substantial growth since its mid-20th-century inception, driven by the discovery of eligible materials and innovative assembly technologies. Of these materials, micro- and nanoscopic substrates have received far less interest than their macroscopic counterparts; however, this is changing. The catalogue of eligible materials, including nanoparticles, quantum dots, polymers, proteins, cells and liposomes, along with some well-established layer-by-layer technologies, have combined to unlock impactful applications in biomedicine, as well as other areas like food fortification, and water remediation. To access these fields, several well-established technologies have been used, including tangential flow filtration, fluidized bed, atomization, electrophoretic assembly, and dielectrophoresis. Despite the invention of these technologies, the field of particle layer-by-layer still requires further technological development to achieve a high-yield, automatable, and industrially ready process, a requirement for the diverse, reactionary field of biomedicine and high-throughput pharmaceutical industry. This review provides a background on layer-by-layer, focusing on how its constituent building blocks and bonding mechanisms enable unmatched versatility. The discussion then extends to established and recent technologies employed for coating micro- and nanoscopic matter, evaluating their drawbacks and advantages, and highlighting promising areas in microfluidic approaches, where one distinctly auspicious technology emerges, acoustofluidics. The review also explores the potential and demonstrated application of acoustofluidics in layer-by-layer technology, as well as analyzing existing acoustofluidic technologies beyond LbL coating in areas such as cell trapping, cell sorting, and multidimensional particle manipulation. Finally, the review concludes with future perspectives on layer-by-layer nanoparticle coating and the potential impact of integrating acoustofluidic methods.

Programmable "triple attack" cancer therapy through in situ activation of disulfiram toxification combined with phototherapeutics

Effectively and completely eliminating residual tumor cells is the key to reducing the risk of tumor metastasis and recurrence. Designing an "ideal" nanoplatform for programmable cancer therapy has great prospects for completely eliminating residual tumor cells. Herein, an intelligent nanoplatform of disulfiram (DSF)-loaded CuS-tannic acid nanohexahedrons (denoted as "DSF-CuS@TA") with thermal- and pH-sensitive degradation, as well as near-infrared (NIR-II) phototherapeutics properties, was constructed. And then, it was employed for in situ DSF toxification activation programmable "triple attack" cancer therapy. After accumulating in the tumor, DSF-CuS@TA first releases the loaded Cu(DTC)2, and simultaneously degrades and releases Cu2+ and DSF under mildly acidic stimulation to trigger instant intratumoral Cu(DTC)2 chelation, thereby achieving the "first strike." Next, under irradiation by a NIR-II laser, light energy is converted into heat to generate NIR-II photothermal therapy, thereby achieving the second strike. Subsequently, under thermal stimulation, DSF-CuS@TA degrades further, triggering the chelation of Cu(DTC)2 for a second time to reach the third strike. As expected, in vitro and in vivo studies showed that the synergistic integration of DSF-based programmed chemotherapy and NIR-II phototherapeutics could achieve effective tumor removal. Therefore, we propose a novel type of programmed therapy against cancer by designing a nanoplatform via "nontoxicity-to-toxicity" chemical chelation transformation.

Advances in biomimetic nanomaterial delivery systems: harnessing nature's inspiration for targeted drug delivery

The properties of nanomaterials make them promising and advantageous for use in drug delivery systems, but challenges arise from the immune system's recognition of exogenous nanoparticles, leading to their clearance and reduced targeting efficiency. Drawing inspiration from nature, this paper explores biomimetic strategies to transform recognizable nanomaterials into a "camouflaged state." The focal point of this paper is the exploration of bionic nanoparticles, with a focus on cell membrane-coated nanoparticles. These biomimetic structures, particularly those mimicking red blood cells (RBCs), white blood cells (WBCs), platelets, and cancer cells, demonstrate enhanced drug delivery efficiency and prolonged circulation. This article underscores the versatility of these biomimetic structures across diverse diseases and explores the use of hybrid cell membrane-coated nanoparticles as a contemporary trend. This review also investigated exosomes and protein bionic nanoparticles, emphasizing their potential for specific targeting, immune evasion, and improved therapeutic outcomes. We expect that this continued development based on biomimetic nanomaterials will contribute to the efficiency and safety of disease treatment.

What matters for drug delivery to tumor by nanoparticles: Gaining insights from PBPK/PD simulation of drug nanocrystals

Background and purpose

In our previous studies, drug nanocrystals were directly prepared by solution crystallization, possessing uniform particle size and morphology suitable for intravenous (IV) injection. These nanocrystals accumulated in a small percentage of their injected dose in tumor-bearing mice but showed similar anti-tumor effectiveness and much-reduced side effects compared with current commercial solubilized and encapsulated delivery systems.

Experimental approach

In this study, we aimed to delineate possible controlling factors for the pharmacokinetics (PK) and biodistribution behaviors of paclitaxel (PTX) nanocrystals tested in mice by applying physiologically based pharmacokinetics (PBPK) modeling, coupled with pharmacodynamics (PD) simulation, to the data.

Key Results

Our results show that clearance of the drug plays a significant, if not the most important, role in determining tissue distribution, including tumor accumulation of PTX nanocrystals. Surface treatment of drug nanocrystals with polymeric surfactants also appeared to affect PK profiles and PD outcomes. Importantly, when scaled to model human parameters, our PK/PD simulations suggest that drug distribution in humans, as opposed to animal models, was significantly influenced by tissue partitioning rather than drug clearance. This finding could facilitate the design and development of future drug delivery systems.

Conclusion

Drug nanocrystals deposited in tissues, including tumors, could therefore act as depots, releasing the drug back into the circulation, possibly contributing to extended treatment, as well as any detrimental effects.

In Situ Aggregated Nanomanganese Enhances Radiation-Induced Antitumor Immunity

Radiosensitizers play a pivotal role in enhancing radiotherapy (RT). One of the challenges in RT is the limited accumulation of nanoradiosensitizers and the difficulty in activating antitumor immunity. Herein, a smart strategy was used to achieve in situ aggregation of nanomanganese adjuvants (MnAuNP-C&B) to enhance RT-induced antitumor immunity. The aggregated MnAuNP-C&B system overcomes the shortcomings of small-sized nanoparticles that easily flow back into blood vessels and diffuse into surrounding tissues, and it also prolongs the retention time of nanomanganese within cancer cells and tumors. The MnAuNP-C&B system significantly enhances the radiosensitization effect in RT. Additionally, the pH-responsive disassembly of MnAuNP-C&B triggers the release of Mn2+, further promoting RT-induced activation of the STING pathway and eliciting robust antitumor immunity. Overall, our study presents a smart strategy wherein in situ aggregation of nanomanganese effectively inhibits tumor growth through radiosensitization and the activation of antitumor immunity.