Mitochondrial Glutathione Depletion Nanoshuttles for Oxygen-Irrelevant Free Radicals Generation: A Cascaded Hierarchical Targeting and Theranostic Strategy Against Hypoxic Tumor

Breaking the Chains of Therapeutic Blockade: Pyroptosis-Induced Photothermal-Chemotherapy with Targeted Nanoprobes in Triple-Negative Breast Cancer

There is an important clinical need and social significance, especially for young patients, to explore a new breast-conserving strategy that is not dependent on biomarkers for anti-triple-negative breast cancer. Disulfiram, historically employed for the treatment of chronic alcoholism, has recently emerged as a promising antitumor agent in combination with Cu2+. However, reported disulfiram-Cu2+ codelivery regimens often suffer from instability as well as inadequate drug metabolism, which is detrimental to the production and action of the antitumor active ingredient copper(II) bis(diethyldithiocarbamate). To address this obstacle, this study tested nanosystems ICG-CuET@PLGA-CS-HA (IC@PCH) nanoparticles (NPs) carrying the chemotherapeutic agent copper(II) bis(diethyldithiocarbamate) and photosensitizer indocyanine green for the efficient delivery of antitumor drugs. Benefiting from the involvement of hyaluronic acid, the prepared IC@PCH NPs not only targeted CD44 on the surface of tumor cells but also showed a longer in vivo circulation time. The in vitro and in vivo results demonstrated that IC@PCH NP-mediated photothermal-chemotherapy treatment led to pyroptosis via the NLRP3/caspase-1 classical pathway, which had a significant therapeutic effect on triple-negative breast cancer. In addition, targeting IC@PCH NPs allows photoacoustic-magnetic resonance-fluorescence trimodal imaging, which is capable of detecting more insidious cancer foci and opens up new avenues for precise cancer diagnosis and treatment.

Intrinsic anti-inflammatory nanomedicines for enhanced pain management

Introduction

Effective postoperative pain management remains a significant challenge due to the severe side effects of opioids and the limitations of existing analgesic delivery systems. Inflammation plays a critical role in pain exacerbation, highlighting the need for therapies that combine analgesic effects with intrinsic anti-inflammatory properties.

Methods

Herein, we develop an intrinsic anti-inflammatory nanomedicine designed to enhance pain management by integrating controlled anesthetic release with inherent anti-inflammatory activity. Our nanoplatform utilizes dendritic mesoporous silica nanoparticles (MSNs) loaded with levobupivacaine and coated with Rg3-based liposomes derived from ginsenoside Rg3, termed LMSN-bupi.

Results

The MSNs enable sustained and controlled release of the local anesthetic, while the Rg3-liposome coating provides intrinsic anti-inflammatory effects by inhibiting macrophage activation. In animal models, LMSN-bupi demonstrates significantly prolonged analgesic effects and attenuated inflammatory responses compared to traditional liposome-decorated nanoparticles (TMSN-bupi) (n = 5).

Discussion

These findings underscore the potential of intrinsic anti-inflammatory nanomedicines in enhancing pain management, offering a promising strategy to overcome the limitations of current therapies and improve patient outcomes in postoperative care.

Recent advances in mitochondria-targeting theranostic agents

For its vital role in maintaining cellular activity and survival, mitochondrion is highly involved in various diseases, and several strategies to target mitochondria have been developed for specific imaging and treatment. Among these approaches, theranostic may realize both diagnosis and therapy with one integrated material, benefiting the simplification of treatment process and candidate drug evaluation. A variety of mitochondria-targeting theranostic agents have been designed based on the differential structure and composition of mitochondria, which enable more precise localization within cellular mitochondria at disease sites, facilitating the unveiling of pathological information while concurrently performing therapeutic interventions. Here, progress of mitochondria-targeting theranostic materials reported in recent years along with background information on mitochondria-targeting and therapy have been briefly summarized, determining to deliver updated status and design ideas in this field to readers.

Breakthrough of Hypoxia Limitation by Tumor-Targeting Photothermal Therapy-Enhanced Radiation Therapy

Purpose

To address the problem of suboptimal reactive oxygen species (ROS) production in Radiation therapy (RT) which was resulted from exacerbated tumor hypoxia and the heterogeneous distribution of radiation sensitizers.

Materials and Methods

In this work, a novel nanomedicine, designated as PLGA@IR780-Bi-DTPA (PIBD), was engineered by loading the radiation sensitizer Bi-DTPA and the photothermal agent IR780 onto poly(lactic-co-glycolic acid) (PLGA). This design leverages the tumor-targeting ability of IR780 to ensure selective accumulation of the nanoparticles in tumor cells, particularly within the mitochondria. The effect of the photothermal therapy-enhanced radiation therapy was also examined to assess the alleviation of hypoxia and the enhancement of radiation sensitivity.

Results

The PIBD nanoparticles exhibited strong capacity in mitochondrial targeting and selective tumor accumulation. Upon activation by 808 nm laser irradiation, the nanoparticles effectively alleviated local hypoxia by photothermal effect enhanced blood supplying to improve oxygen content, thereby enhancing the ROS production for effective RT. Comparative studies revealed that PIBD-induced RT significantly outperformed conventional RT in treating hypoxic tumors.

Conclusion

This design of tumor-targeting photothermal therapy-enhanced radiation therapy nanomedicine would advance the development of targeted drug delivery system for effective RT regardless of hypoxic microenvironment.

Potentiating dual-directional immunometabolic regulation with nanomedicine to enhance anti-tumor immunotherapy following incomplete photothermal ablation

Photothermal therapy (PTT) is a promising cancer treatment method due to its ability to induce tumor-specific T cell responses and enhance therapeutic outcomes. However, incomplete PTT can leave residual tumors that often lead to new metastases and decreased patient survival in clinical scenarios. This is primarily due to the release of ATP, a damage-associated molecular pattern that quickly transforms into the immunosuppressive metabolite adenosine by CD39, prevalent in the tumor microenvironment, thus promoting tumor immune evasion. This study presents a photothermal nanomedicine fabricated by electrostatic adsorption among the Fe-doped polydiaminopyridine (Fe-PDAP), indocyanine green (ICG), and CD39 inhibitor sodium polyoxotungstate (POM-1). The constructed Fe-PDAP@ICG@POM-1 (FIP) can induce tumor PTT and immunogenic cell death when exposed to a near-infrared laser. Significantly, it can inhibit the ATP-adenosine pathway by dual-directional immunometabolic regulation, resulting in increased ATP levels and decreased adenosine synthesis, which ultimately reverses the immunosuppressive microenvironment and increases the susceptibility of immune checkpoint blockade (aPD-1) therapy. With the aid of aPD-1, the dual-directional immunometabolic regulation strategy mediated by FIP can effectively suppress/eradicate primary and distant tumors and evoke long-term solid immunological memory. This study presents an immunometabolic control strategy to offer a salvage option for treating residual tumors following incomplete PTT.

Optimized silicate nanozymes with atomically incorporated iron and manganese for intratumoral coordination-enhanced once-for-all catalytic therapy

Although plant-derived cancer therapeutic products possess great promise in clinical translations, they still suffer from quick degradation and low targeting rates. Herein, based on the oxygen vacancy (OV)-immobilization strategy, an OV-enriched biodegradable silicate nanoplatform with atomically dispersed Fe/Mn active species and polyethylene glycol modification was innovated for loading gallic acid (GA) (noted as FMMPG) for intratumoral coordination-enhanced multicatalytic cancer therapy. The OV-enriched FMMPG nanozymes with a narrow band gap (1.74 eV) can be excited by a 650 nm laser to generate reactive oxygen species. Benefiting from the Mn-O bond in response to the tumor microenvironment (TME), the silicate skeleton in FMMPG collapses and completely degrades after 24 h. The degraded metal M (M = Fe, Mn) ions and released GA can in situ produce a stable M-GA nanocomplex at tumor sites. Importantly, the formed M-GA with strong reductive ability can transform H2O2 into the fatal hydroxyl radical, causing serious oxidative damage to the tumor. The released Fe3+ and Mn2+ can serve as enhanced contrast agents for magnetic resonance imaging, which can track the chemodynamic and photodynamic therapy processes. The work offers a reasonable strategy for a TME-responsive degradation and intratumoral coordination-enhanced multicatalytic therapy founded on bimetallic silicate nanozymes to achieve desirable tumor theranostic outcomes.

Topically applied pH-responsive nanogels for alkyl radical-based therapy against psoriasiform hyperplasia

Phototherapy is a conventional antipsoriatic approach based on oxygen-relevant generation of oxidative stress to inhibit keratinocyte hyperproliferation. However, this therapy can be restricted due to local hypoxia in psoriatic lesions. The generation of alkyl radicals is oxygen-independent and suppresses hyperproliferation. Herein, we established alkyl radical-based therapy to treat psoriatic hyperplasia. Because alkyl radicals are short-lived compounds, we loaded 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (AIPH) as a precursor of alkyl radicals into the chitosan nanogels to improve stability. The present study presented a topically applied nanogel that led to a pH-responsive network sensitive to skin pH. This pH responsiveness of the nanogels allowed fast alkyl radical release in the target site. The physicochemical properties of the prepared nanogels were determined through size, zeta potential, scanning electron microscopy, and absorption spectroscopy. The antipsoriatic activity was examined with keratinocyte- and animal-based studies. The nanogels displayed a smooth and spherical morphology with a hydrodynamic diameter of 215 nm. This size was largely increased as the environmental pH increased to 6. The nanogels heated at 44 °C produced alkyl radicals to induce keratinocyte death through the necrosis pathway. Bioimaging demonstrated that topically applied nanogels could deliver alkyl radicals into the epidermis. This targeting was accompanied by the accumulation of free radicals in the epidermis according to the 2',7'-dichlorodihydrofluorescein diacetate assay. The imiquimod-stimulated psoriasiform animal model indicated a remarkable reduction in erythema, scaling, and overexpressed cytokines upon topical treatment of the nanogels. The transepidermal water loss of the psoriasiform skin was inhibited from 51.7 to 27.0 g/m2/h, suggesting barrier function recovery by the nanocarriers. The nanogels lowered hyperplasia by decreasing the epidermal thickness from 212 to 89 μm. The incorporation of 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) as a pH-sensitive fluorescence dye in the nanogels could be used to diagnose the severity of the psoriasiform plaque due to the stronger fluorescence of HPTS in skin with lower pH (psoriasiform skin pH = 4.4) than in healthy skin (pH = 4.9). It was possible to deliver the prepared nanogels into the epidermis to restrain hyperplasia without causing cutaneous irritation.

Artificial nano-red blood cells nanoplatform with lysosomal escape capability for ultrasound imaging-guided on-demand pain management

Postoperative pain management would benefit significantly from an anesthetic that could take effect in an on-demand manner. An ultrasound would be an appropriate tool for such nanoplatform because it is widely used in clinical settings for ultrasound-guided anesthesia. Herein, we report a nanoplatform for postoperative on-demand pain management that can effectively enhance their analgesic time while providing ultrasonic imaging. Levobupivacaine and perfluoropentane were put into dendritic mesoporous silica and covered with red blood cell membranes to make the pain relief last longer in living organisms. The generated nanoplatform with gas-producing capability is ultrasonic responsive and can finely escape from the lysosomal in cells under ultrasound irradiation, maximizing the anesthetic effect with minimal toxicity. Using an incision pain model in vivo, levobupivacaine's sustained and controlled release gives pain reduction for approximately 3 days straight. The duration of pain relief is over 20 times greater than with a single injection of free levobupivacaine. Effective pain management was reached in vivo, and the pain reduction was enhanced by repeated ultrasonic irradiation. There was no detectable systemic or tissue injury under either of the treatments. Thus, our results suggest that nanoplatform with lysosomal escape capability can provide a practical ultrasound imaging-guided on-demand pain management strategy. STATEMENT OF SIGNIFICANCE: On-demand pain management is essential to postoperative patients. However, the traditional on-demand pain management strategy is hampered by the limited tissue penetration depth of near-infrared stimuli and the lack of proper imaging guidance. The proposed research is significant because it provides a nanoplatform for deep penetrated ultrasound controlled pain management under clinical applicable ultrasound imaging guidance. Moreover, the nanoplatform with prolonged retention time and lysosomal escape capability can provide long-term pain alleviation. Therefore, our results suggest that nanoplatform with lysosomal escape capability can provide an effective strategy for ultrasound imaging-guided on-demand pain management.

Injectable versatile liquid-solid transformation implants alliance checkpoint blockade for magnetothermal dynamic-immunotherapy

The ongoing circulating energy loss, low reactive oxygen species (ROS) accumulation and poor immunogenicity of tumors make it difficult to induce sufficient immunogenic cell death (ICD) in the tumor immunosuppressive microenvironment (TIME), resulting in unsatisfactory immunotherapy efficacy. Furthermore, for highly malignant tumors, simply enhancing ICD is insufficient for exhaustively eliminating the tumor and inhibiting metastasis. Herein, we propose a unique magnetothermal-dynamic immunotherapy strategy based on liquid-solid transformation porous versatile implants (Fe₃O₄/AIPH@PLGA) that takes advantage of less energy loss and avoids ongoing circulating losses by minimally invasive injection into tumors. In addition, the magnetothermal effect regresses and eliminates tumors that are not limited by penetration to simultaneously trigger 2,2′-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (AIPH) decomposition and generate a large amount of oxygen-irrelevant free radicals and heat shock protein (HSP) accumulation by heating, evoking both intracellular oxidative stress and endoplasmic reticulum (ER) stress to induce large-scale ICD and enhance tumor immunogenicity. More importantly, in orthotopic bilateral breast tumor models, a significant therapeutic effect was obtained after combining amplified ICD with CTLA4 checkpoint blockade. The 21-day primary and distant tumor inhibition rates reached 90%, and the underlying mechanism of the effective synergetic strategy of inducing the T-cell-related response, the immune memory effect and TIME reprogramming in vivo was verified by immune cell analyses. This remarkable therapeutic effect provides a new direction for antitumor immunotherapy based on magnetothermally controlled oxygen-independent free radical release.

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Injectable versatile liquid-solid phase transformation Fe₃O₄/AIPH@PLGA gel implants are constructed for the first time.

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The implants triggered magnetothermal dynamic therapy and successfully addressed two key barriers limiting the efficacy of immunogenic cell death (ICD): low reactive oxygen species (ROS) accumulation and poor immunogenicity.

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The implants promoting DC maturation, recognition and presentation of antigens. Combined with CTLA4 blockade, the function of Treg cells was inhibited to transform the “cold” TIME into “hot”.

Intensity-adjustable pain management with prolonged duration based on phase-transitional nanoparticles-assisted ultrasound imaging-guided nerve blockade

Background

The lack of a satisfactory strategy for postoperative pain management significantly impairs the quality of life for many patients. However, existing nanoplatforms cannot provide a longer duration of nerve blockage with intensity-adjustable characteristics under imaging guidance for clinical applications.

Results

To overcome this challenge, we proposed a biocompatible nanoplatform that enables high-definition ultrasound imaging-guided, intensity-adjustable, and long-lasting analgesia in a postoperative pain management model in awake mice. The nanoplatform was constructed by incorporating perfluoropentane and levobupivacaine with red blood cell membranes decorated liposomes. The fabricated nanoplatform can achieve gas-producing and can finely escape from immune surveillance in vivo to maximize the anesthetic effect. The analgesia effect was assessed from both motor reactions and pain-related histological markers. The findings demonstrated that the duration of intensity-adjustable analgesia in our platform is more than 20 times longer than free levobupivacaine injection with pain relief for around 3 days straight. Moreover, the pain relief was strengthened by repeatable ultrasound irradiation to effectively manage postoperative pain in an intensity-adjustable manner. No apparent systemic and local tissue injury was detected under different treatments.

Conclusion

Our results suggest that nanoplatform can provide an effective strategy for ultrasound imaging-guided intensity-adjustable pain management with prolonged analgesia duration and show considerable transformation prospects.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01707-z.

Dual-responsive and NIR-driven free radical nanoamplifier with glutathione depletion for enhanced tumor-specific photothermal/thermodynamic/chemodynamic synergistic Therapy

The efficacy of free radical-based therapeutic strategies is severely hindered by nonspecific accumulation, premature release and glutathione (GSH) scavenging effects. Herein, a tumor microenvironment-responsive MPDA/AIPH@Cu-TA@HA (abbreviated as MACTH) nanoplatform was constructed by coating Cu²⁺ and tannic acid (TA) on the surface of azo initiator (AIPH)-loaded mesoporous polydopamine (MPDA) nanoparticles and further modifying them with hyaluronic acid (HA) to achieve tumor-specific photothermal/thermodynamic/chemodynamic synergistic therapy (PTT/TDT/CDT). Once accumulated and internalized into cancer cells through CD44 receptor-mediated active targeting and endocytosis, the HA shell of MACTH would be preliminarily degraded by hyaluronidase (HAase) to expose the Cu-TA metal-phenolic networks, which would further dissociate in response to an acidic lysosomal environment, leading to HAase/pH dual-responsive release of Cu²⁺ and AIPH. On the one hand, the released Cu²⁺ could deplete the overexpressed GSH via redox reactions and produce Cu⁺, which in turn catalyzes endogenous H₂O₂ into highly cytotoxic hydroxyl radicals (˙OH) for CDT. On the other hand, the local hyperthermia generated by MACTH under 808 nm laser irradiation could not only augment CDT efficacy through accelerating the Cu⁺-mediated Fenton-like reaction, but also trigger the decomposition of AIPH to produce biotoxic alkyl radicals (˙R) for TDT. The consumption of GSH and accumulation of oxygen-independent free radicals (˙OH/˙R) synergistically amplified intracellular oxidative stress, resulting in substantial apoptotic cell death and significant tumor growth inhibition. Collectively, this study provides a promising paradigm for customizing stimuli-responsive free radical-based nanoplatforms to achieve accurate and efficacious cancer treatment.