NIR-Responsive Polypeptide Nanocomposite Generates NO Gas, Mild Photothermia, and Chemotherapy to Reverse Multidrug-Resistant Cancer

Novel 131-iodine labeled and ultrasound-responsive nitric oxide and reactive oxygen species controlled released nanoplatform for synergistic sonodynamic/nitric oxide/chemodynamic/radionuclide therapy

Nitric oxide (NO) and reactive oxygen species (ROS) embody excellent potential in cancer therapy. However, as a small molecule, their targeted delivery and precise, controllable release are urgently needed to achieve accurate cancer therapy. In this paper, a novel US-responsive bifunctional molecule (SD) and hyaluronic acid-modified MnO2 nanocarrier was developed, and a US-responsive NO and ROS controlled released nanoplatform was constructed. US can trigger SD to release ROS and NO simultaneously at the tumor site. Thus, SD served as acoustic sensitizer for sonodynamic therapy and NO donor for gas therapy. In the tumor microenvironment, the MnO2 nanocarrier can effectively deplete the highly expressed GSH, and the released Mn2+ can make H2O2 to produce .OH by Fenton-like reaction, which exhibited a strong chemodynamic effect. The high concentration of ROS and NO in cancer cell can induce cancer cell apoptosis ultimately. In addition, toxic ONOO-, which was generated by the reaction of NO and ROS, can effectively cause mitochondrial dysfunction, which induced the apoptosis of tumor cells. The 131I was labeled on the nanoplatform, which exhibited internal radiation therapy for tumor therapy. In -vitro and -vivo experiments showed that the nanoplatform has enhanced biocompatibility, and efficient anti-tumor potential, and it achieves synergistic sonodynamic/NO/chemodynamic/radionuclide therapy for cancer.

Advances and perspectives in phototherapy-based combination therapy for cancer treatment

Phototherapy, including photothermal therapy (PTT) and photodynamic therapy (PDT), has the advantages of spatiotemporal selectivity, non-invasiveness, and negligible drug resistance. Phototherapy has been approved for treating superficial epidermal tumors. However, its therapeutic efficacy is limited by the hypoxic tumor microenvironment and the highly expressed heat shock protein. Moreover, poor tissue penetration and focused irradiation laser region in phototherapy make treating deep tissues and metastatic tumors challenging. Combination therapy strategies, which integrate the advantages of each treatment and overcome their disadvantages, can significantly improve the therapeutic efficacy. Recently, many combination therapy strategies have been reported. Our study summarizes the strategies used for combining phototherapy with other cancer treatments such as chemotherapy, immunotherapy, sonodynamic therapy, gas therapy, starvation therapy, and chemodynamic therapy. Some research cases were selected to analyze the combination therapy effect, delivery platform feature, and synergetic anticancer mechanisms. Moreover, additional research cases are summarized in the tables. This review provides strong evidence that phototherapy-based combination strategies can enhance the anticancer effect compared with phototherapy alone. Additionally, the challenges and future perspectives associated with these combinational therapies are discussed.

Bacterial lipase-responsive polydopamine nanoparticles for detection and synergistic therapy of wound biofilms infection

Wound biofilms represent an elusive conundrum in contemporary treatment and diagnostic options, accredited to their escalating antibiotic resistance and interference in chronic wound healing processes. Here, we developed mesoporous polydopamine (mPDA) nanoparticles, and grafted with rhodamine B (Rb) as biofilm lipase responsive detection probe, followed by π - π stacking mediated ciprofloxacin (CIP) loading to create mP-Rb@CIP nanoparticles. mPDA NPs with a melanin structure could quench fluorescence emissions of Rb. Once encountering biofilm in vivo, the ester bond in Rb and mPDA is hydrolyzed by elevated lipase concentrations, triggering the liberation of Rb and restore fluorescence emissions to achieve real-time imaging of biofilm-infected wounds. Afterwards, the 808 nm near-infrared (NIR) illumination initiates a spatiotemporal controlled antibacterial photothermal therapy (PTT), boosting its effectiveness through photothermal-triggered CIP release for synergistic biofilm eradication. The mP-Rb@CIP platform exhibits dual diagnostic and therapeutic functions, efficaciously treating biofilm-infected wounds in vivo and in vitro. Particularly, the mP-Rb@CIP/NIR procedure expedites wound-healing by alleviating oxidative stress, modulating inflammatory mediators, boosting collagen synthesis, and promoting angiogenesis. Taken together, the theranostic nanosystem strategy holds significant potential for addressing wound biofilm-associated infections.

Stimuli-responsive peptide assemblies: Design, self-assembly, modulation, and biomedical applications

Peptide molecules have design flexibility, self-assembly ability, high biocompatibility, good biodegradability, and easy functionalization, which promote their applications as versatile biomaterials for tissue engineering and biomedicine. In addition, the functionalization of self-assembled peptide nanomaterials with other additive components enhances their stimuli-responsive functions, promoting function-specific applications that induced by both internal and external stimulations. In this review, we demonstrate recent advance in the peptide molecular design, self-assembly, functional tailoring, and biomedical applications of peptide-based nanomaterials. The strategies on the design and synthesis of single, dual, and multiple stimuli-responsive peptide-based nanomaterials with various dimensions are analyzed, and the functional regulation of peptide nanomaterials with active components such as metal/metal oxide, DNA/RNA, polysaccharides, photosensitizers, 2D materials, and others are discussed. In addition, the designed peptide-based nanomaterials with temperature-, pH-, ion-, light-, enzyme-, and ROS-responsive abilities for drug delivery, bioimaging, cancer therapy, gene therapy, antibacterial, as well as wound healing and dressing applications are presented and discussed. This comprehensive review provides detailed methodologies and advanced techniques on the synthesis of peptide nanomaterials from molecular biology, materials science, and nanotechnology, which will guide and inspire the molecular level design of peptides with specific and multiple functions for function-specific applications.

Glutathione-triggered release of SO2 gas to augment oxidative stress for enhanced chemodynamic and sonodynamic therapy

Recently, gas therapy has emerged as a promising alternative treatment for deep-seated tumors. However, some challenges regarding insufficient or uncontrolled gas generation as well as unclear therapeutic mechanisms restrict its further clinical application. Herein, a well-designed nanoreactor based on intracellular glutathione (GSH)-triggered generation of sulfur dioxide (SO2) gas to augment oxidative stress has been developed for synergistic chemodynamic therapy (CDT)/sonodynamic therapy (SDT)/SO2 gas therapy. The nanoreactor (designed as CCM@FH-DNs) is constructed by employing iron-doped hollow mesoporous silica nanoparticles as carriers, the surface of which was modified with the SO2 prodrug 2,4-dinitrobenzenesulfonyl (DNs) and further coated with cancer cell membranes for homologous targeting. The CCM@FH-DNs can not only serve as a Fenton-like agent for CDT, but also as a sonosensitizer for SDT. Importantly, CCM@FH-DNs can release SO2 for SO2-mediated gas therapy. Both in vitro and in vivo evaluations demonstrate that the CCM@FH-DNs nanoreactor performs well in augmenting oxidative stress for SO2 gas therapy-enhanced CDT/SDT via GSH depletion and glutathione peroxidase-4 enzyme deactivation as well as superoxide dismutase inhibition. Moreover, the doped iron ions ensure that the CCM@FH-DNs nanoreactors enable magnetic resonance imaging-guided therapy. Such a GSH-triggered SO2 gas therapy-enhanced CDT/SDT strategy provides an intelligent paradigm for developing efficient tumor microenvironment-responsive treatments.

ROS-driven supramolecular nanoparticles exhibiting efficient drug delivery for chemo/Chemodynamic combination therapy for Cancer treatment

Drug-based supramolecular self-assembling delivery systems have enhanced the bioavailability of chemotherapeutic drugs and reduced systemic side effects; however, improving the delivery efficiency and responsive release ability of these systems remains challenging. This study focuses primarily on the utilization of per-6-thio-β-cyclodextrin (CD) to link a significant quantity of paclitaxel (PTX) via ROS-sensitive thioketal (TK) linkages (designated as CDTP), thereby allowing efficiently drug release when exposed to high levels of reactive oxygen species (ROS) in the tumor microenvironment. To construct these supramolecular nanoparticles (NPs) with CDTP, we introduced PEGylated ferrocene (Fc) through host-guest interactions. The intracellular hydrogen peroxide (H2O2) is converted into hydroxyl radicals (•OH) through the Fc-catalyzed Fenton reaction. Additionally, the generated Fc+ consumes the antioxidant glutathione (GSH). In both in vivo and in vitro experiments, CDTP@Fc-PEG NPs were absorbed effectively by tumor cells, which increased levels of ROS and decreased levels of GSH, disrupting the redox balance of cancer cells and increasing their sensitivity to chemotherapy. Furthermore, CDTP@Fc-PEG NPs exhibited high tumor accumulation and cytotoxicity without causing significant toxicity to healthy organs. Collectively, our results suggest CDTP@Fc-PEG NPs as a promising supramolecular nano-delivery platform for high drug-loading of PTX and synergistic chemotherapy.

H2O2-triggered controllable carbon monoxide delivery for photothermally augmented gas therapy

Carbon monoxide (CO) gas therapy has shown great potential as a very promising approach in the ongoing fight against tumors. However, delivering unstable CO to the tumor site and safely releasing it for maximum efficacy still have unsatisfactory outcomes. In this study, we've developed nanotheranostics (IN-DPPCO NPs) based on conjugated polymer IN-DPP and carbon monoxide (CO) carrier polymer mPEG(CO) for photothermal augmented gas therapy. The IN-DPPCO NPs can release CO with the hydrogen peroxide (H2O2) overexpressed in the tumor microenvironment. Meanwhile, IN-DPPCO NPs exhibit strong absorption in the near-infrared window, showing a high photothermal conversion efficiency of up to 41.5% under 808 nm laser irradiation. In vitro and in vivo experiments demonstrate that these nanotheranostics exhibit good biocompatibility. Furthermore, the synergistic CO/photothermal therapy shows enhanced therapeutic efficacy compared to gas therapy alone. This work highlights the great promise of conjugated polymer nanoparticles as versatile nanocarriers for spatiotemporally controlled and on-demand delivery of gaseous messengers to achieve precision cancer theranostics.

The Emerging Landscape for Combating Resistance Associated with Energy-Based Therapies via Nanomedicine

Cancer represents a serious disease with significant implications for public health, imposing substantial economic burden and negative societal consequences. Compared to conventional cancer treatments, such as surgery and chemotherapy, energy-based therapies (ET) based on athermal and thermal ablation provide distinct advantages, including minimally invasive procedures and rapid postoperative recovery. Nevertheless, due to the complex pathophysiology of many solid tumors, the therapeutic effectiveness of ET is often limited. Nanotechnology offers unique opportunities by enabling facile material designs, tunable physicochemical properties, and excellent biocompatibility, thereby further augmenting the outcomes of ET. Numerous nanomaterials have demonstrated the ability to overcome intrinsic therapeutic resistance associated with ET, leading to improved antitumor responses. This comprehensive review systematically summarizes the underlying mechanisms of ET-associated resistance (ETR) and highlights representative applications of nanoplatforms used to mitigate ETR. Overall, this review emphasizes the recent advances in the field and presents a detailed account of novel nanomaterial designs in combating ETR, along with efforts aimed at facilitating their clinical translation.

Current trends in gas-synergized phototherapy for improved antitumor theranostics

Phototherapy, such as photothermal therapy (PTT) and photodynamic therapy (PDT), has been considered an elegant solution to eradicate tumors due to its minimal invasiveness and low systemic toxicity. Nevertheless, it is still challenging for phototherapy to achieve ideal outcomes and clinical translation due to its inherent drawbacks. Owing to the unique biological functions, diverse gases have attracted growing attention in combining with phototherapy to achieve super-additive therapeutic effects. Specifically, gases such as nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S) have been proven to kill tumor cells by inducing mitochondrial damage in synergy with phototherapy. Additionally, several gases not only enhance the thermal damage in PTT and the reactive oxygen species (ROS) production in PDT but also improve the tumor accumulation of photoactive agents. The inflammatory responses triggered by hyperthermia in PTT are also suppressed by the combination of gases. Herein, we comprehensively review the latest studies on gas-synergized phototherapy for cancer therapy, including (1) synergistic mechanisms of combining gases with phototherapy; (2) design of nanoplatforms for gas-synergized phototherapy; (3) multimodal therapy based on gas-synergized phototherapy; (4) imaging-guided gas-synergized phototherapy. Finally, the current challenges and future opportunities of gas-synergized phototherapy for tumor treatment are discussed. STATEMENT OF SIGNIFICANCE: 1. The novelty and significance of the work with respect to the existing literature. (1) Strategies to design nanoplatforms for gas-synergized anti-tumor phototherapy have been summarized for the first time. Meanwhile, the integration of various imaging technologies and therapy modalities which endow these nanoplatforms with advanced theranostic capabilities has been summarized. (2) The mechanisms by which gases synergize with phototherapy to eradicate tumors are innovatively and comprehensively summarized. 2. The scientific impact and interest. This review elaborates current trends in gas-synergized anti-tumor phototherapy, with special emphases on synergistic anti-tumor mechanisms and rational design of therapeutic nanoplatforms to achieve this synergistic therapy. It aims to provide valuable guidance for researchers in this field.

Wireless Photoactivated Targeted Nanosystem for Oncotherapy Via Synergistic Effects of Hyperthermia/Redox Stress Amplification/GSK-3β Activity Inhibition

Highly soluble salts and gas mediated therapies are emerging antitumor strategies. However, the therapeutic efficacy remains restricted by difficulty in delivering them to the tumor site and poorly controlled release in deep tissues. Here, an intelligent wireless photoactivated targeted nanosystem is designed for delivering LiCl and H2 to tumors for therapy. LiCl causes cell death by inhibiting the activity of GSK-3β. H2 selectively interacts with reactive oxygen species in the tumor, leading to redox stress, which induces apoptosis. The significant heat generated by the nanosystem not only kills tumor cells but also accelerates the dissolution of LiCl and the release of H2. The rapid dissolution of LiCl leads to a surge in intracellular osmotic pressure, which further intensifies the redox stress response and enhances the efficiency of therapy. The nanosystem shows efficient tumor therapeutic capability via synergistic effects of hyperthermia/redox stress amplification/GSK-3β activity inhibition.

Polyphenol-Based Nanosystems for Next-Generation Cancer Therapy: Multifunctionality, Design, and Challenges

With the continuous updating of cancer treatment methods and the rapid development of precision medicine in recent years, there are higher demands for advanced and versatile drug delivery systems. Scientists are committed to create greener and more effective nanomedicines where the carrier is no longer limited to a single function of drug delivery. Polyphenols, which can act as both active ingredients and fundamental building blocks, are being explored as potential multifunctional carriers that are efficient and safe for design purposes. Due to their intrinsic anticancer activity, phenolic compounds have shown surprising expressiveness in ablation of tumor cells, overcoming cancer multidrug resistance (MDR), and enhancing immunotherapeutic efficacy. This review provides an overview of recent advances in the design, synthesis, and application of versatile polyphenol-based nanosystems for cancer therapy in various modes. Moreover, the merits of polyphenols and the challenges for their clinical translation are also discussed, and it is pointed out that the novel polyphenol delivery system requires further optimization and validation.

A supramolecular nanoplatform for imaging-guided phototherapies via hypoxia tumour microenvironment remodeling

Photodynamic therapy (PDT) has emerged as an invasive and promising antitumour treatment, however, the hypoxia in deep tumour tissues and the poor water-solubility of photosensitizers as bottlenecks greatly hinder PDT efficiency. Herein, a tumour microenvironment (TME) activated supramolecular nanoplatform consisting of the pillar[5]arene-based amphiphilic polymer POPD, the phototherapeutic agent Cy7-CN, respiratory medication atovaquone (ATO) and chemotherapeutic drug pyridinyl camptothecin (CPT-Py) was constructed for imaging-guided hypoxia-ameliorated phototherapies. Owing to host-guest interaction, the photochemical and photophysical properties of cyanine were improved exceedingly due to the suppression of π-π stacking. Triggered by the acidic microenvironment in tumour sites, the supramolecular nanoplatform would dissociate and release CPT-Py and ATO which inhibits mitochondria-associated oxidative phosphorylation (OXPHOS) and encourages more oxygen to be used in enhanced PDT. In vitro and in vivo studies verified that the rational combination of ATO-enhanced PDT and PTT overcame the disadvantages of single phototherapy and formed mutual promotion, and simultaneously sensitized chemotherapeutic drugs, which resulted in high tumour inhibition. It is hoped that the supramolecular nanoplatform could shed light on the development of phototherapeutic agents.

Meta-Analysis of Nanoparticle Distribution in Tumors and Major Organs in Tumor-Bearing Mice

Low tumor delivery efficiency is a critical barrier in cancer nanomedicine. This study reports an updated version of "Nano-Tumor Database", which increases the number of time-dependent concentration data sets for different nanoparticles (NPs) in tumors from the previous version of 376 data sets with 1732 data points from 200 studies to the current version of 534 data sets with 2345 data points from 297 studies published from 2005 to 2021. Additionally, the current database includes 1972 data sets for five major organs (i.e., liver, spleen, lung, heart, and kidney) with a total of 8461 concentration data points. Tumor delivery and organ distribution are calculated using three pharmacokinetic parameters, including delivery efficiency, maximum concentration, and distribution coefficient. The median tumor delivery efficiency is 0.67% injected dose (ID), which is low but is consistent with previous studies. Employing the best regression model for tumor delivery efficiency, we generate hypothetical scenarios with different combinations of NP factors that may lead to a higher delivery efficiency of >3%ID, which requires further experimentation to confirm. In healthy organs, the highest NP accumulation is in the liver (10.69%ID/g), followed by the spleen 6.93%ID/g and the kidney 3.22%ID/g. Our perspective on how to facilitate NP design and clinical translation is presented. This study reports a substantially expanded "Nano-Tumor Database" and several statistical models that may help nanomedicine design in the future.

Near-Infrared-Induced NO-Releasing Photothermal Adhesive Hydrogel with Enhanced Antibacterial Properties

Bacterial infection and the development of antibiotic-resistant bacteria have decreased the effectiveness of traditional antibiotic treatments for wound healing. The design of a multifunctional adhesive hydrogel with antibacterial activity, self-healing properties, and on-demand removability to promote wound healing is highly desirable. In this work, a photothermal cyclodextrin with a NO-releasing moiety has been incorporated within an oxidized sodium alginate conjugated polyacrylamide (OS@PA) hydrogel to get a photothermal NO-releasing GSNOCD-OS@PA hydrogel. Such a multifunctional hydrogel has the unique feature of combined antibacterial activity as a result of a controlled photothermal effect and NO gas release under an 808 near-infrared laser. Because of oxidized sodium alginate (OSA), the hydrogel matrix easily adheres to the skin under twisted and bent states. In vitro cytotoxicity analysis against 3T3 cells showed that the hydrogels OS@PA and GSNOCD-OS@PA are noncytotoxic under laser exposure. The temperature-induced NO release by GSNOCD-OS@PA reached 31.7 mg/L when irradiated with an 808 nm laser for 10 min. The combined photothermal therapy and NO release from GSNOCD-OS@PA effectively reduced viability of both Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) to 3 and 5%, respectively. Importantly, the phototherapeutic NO-releasing platform displayed effective fibroblast proliferation in a cell scratch assay.

Nanodelivery systems: An efficient and target-specific approach for drug-resistant cancers

BACKGROUND

Cancer treatment is still a global health challenge. Nowadays, chemotherapy is widely applied for treating cancer and reducing its burden. However, its application might be in accordance with various adverse effects by exposing the healthy tissues and multidrug resistance (MDR), leading to disease relapse or metastasis. In addition, due to tumor heterogeneity and the varied pharmacokinetic features of prescribed drugs, combination therapy has only shown modestly improved results in MDR malignancies. Nanotechnology has been explored as a potential tool for cancer treatment, due to the efficiency of nanoparticles to function as a vehicle for drug delivery.

METHODS

With this viewpoint, functionalized nanosystems have been investigated as a potential strategy to overcome drug resistance.

RESULTS

This approach aims to improve the efficacy of anticancer medicines while decreasing their associated side effects through a range of mechanisms, such as bypassing drug efflux, controlling drug release, and disrupting metabolism. This review discusses the MDR mechanisms contributing to therapeutic failure, the most cutting-edge approaches used in nanomedicine to create and assess nanocarriers, and designed nanomedicine to counteract MDR with emphasis on recent developments, their potential, and limitations.

CONCLUSIONS

Studies have shown that nanoparticle-mediated drug delivery confers distinct benefits over traditional pharmaceuticals, including improved biocompatibility, stability, permeability, retention effect, and targeting capabilities.

Thiol-Disulfide Exchange Coordinates the Release of Nitric Oxide and Dexamethasone for Synergistic Regulation of Intestinal Microenvironment in Colitis

The cell-specific functions of nitric oxide (NO) in the intestinal microenvironment orchestrate its therapeutic effects in ulcerative colitis. While most biomaterials show promise by eliciting the characteristics of NO, the insufficient storage, burst release, and pro-inflammatory side effects of NO remain as challenges. Herein, we report the development of thiol-disulfide hybrid mesoporous organosilica nanoparticles (MONs) that improve the storage and sustained release of NO, broadening the therapeutic window of NO-based therapy against colitis. The tailored NO-storing nanomaterials coordinated the release of NO and the immunoregulator dexamethasone (Dex) in the intestinal microenvironment, specifically integrating the alleviation of oxidative stress in enterocytes and the reversal of NO-exacerbated macrophage activation. Mechanistically, such a synchronous operation was achieved by a self-motivated process wherein the thiyl radicals produced by NO release cleaved the disulfide bonds to degrade the matrix and release Dex via thiol-disulfide exchange. Specifically, the MON-mediated combination of NO and Dex greatly ameliorated intractable colitis compared with 5-aminosalicylic acid, even after delayed treatment. Together, our results reveal a key contribution of synergistic modulation of the intestinal microenvironment in NO-based colitis therapy and introduce thiol-disulfide hybrid nanotherapeutics for the management of inflammatory diseases and cancer.

Dual-Ligand Synergistic Targeting Anti-Tumor Nanoplatforms with Cascade-Responsive Drug Release

Dual-ligand targeting drug delivery nanoplatforms are considered a promising tool for enhancing the specificity of chemotherapy. However, serious off-target delivery has been observed in current dual-ligand targeting nanoplatforms, as each ligand can independently recognize receptors on the cell membrane surface and guide drug nanocarriers to different cells. To overcome this barrier, a dual-ligand synergistic targeting (DLST) nanoplatform is developed, which can guide chemotherapy treatment specifically to cancer cells simultaneously overexpressing two receptors. This nanoplatform consists of a singlet oxygen (¹O₂) photosensitizer-loaded nanocarrier and a drug-loaded nanocarrier with ¹O₂ responsiveness, which were, respectively, decorated with a pair of complementary DNA sequences and two different ligands. For cancer cells overexpressing both receptors, two nanocarriers can be internalized in larger quantities to cause DNA hybridization-induced nanocarrier aggregation, which further activates ¹O₂-triggered drug release under light irradiation. For cells overexpressing a single receptor, only one type of nanocarrier can be internalized in a large quantity, leading to blocked drug release due to the ultrashort action radius of ¹O₂. In vivo evaluation showed this DLST nanoplatform displayed highly specific tumor treatment with minimized long-term toxicity. This is a highly efficient drug delivery system for DLST chemotherapy, holding great potential for clinical applications.

Doxorubicin-Fe(III)-Gossypol Infinite Coordination Polymer@PDA:CuO2 Composite Nanoparticles for Cost-Effective Programmed Photothermal-Chemodynamic-Coordinated Dual Drug Chemotherapy Trimodal Synergistic Tumor Therapy

To achieve the maximum therapeutic effects and minimize adverse effects of trimodal synergistic tumor therapies, a cost-effective programmed photothermal (PTT)-chemodynamic (CDT)-coordinated dual drug chemotherapy (CT) trimodal synergistic therapy strategy in chronological order is proposed. According to the status or volumes of the tumors, the intensity and time of each therapeutic modality are optimized, and three modalities are combined programmatically and work in chronological order. The optimal synergistic therapy begins with high-intensity PTT for 10 min to ablate larger tumors, followed by medium-intensity CDT for several hours to eliminate medium-sized tumors, and then low-intensity coordinated dual drugs CT lasts over 48 h to clear smaller residual tumors. Composite nanoparticles, made of Fe-coordinated polydopamine mixed with copper peroxide as the cores and their surface dotted with lots of doxorubicin-Fe(III)-gossypol infinite coordination polymers (ICPs), have been developed to implement the strategy. These composite nanoparticles show excellent synergistic effects with the minimum dose of therapeutic agents and result in nearly 100% tumor inhibition for mice bearing PC-3 tumors and no observed recurrence within 60 days of treatment. The ratios of the different therapeutic agents in the composite nanoparticles can be adjusted to accommodate different types of tumors with this cost-effective programmed trimodal therapy strategy.

Advanced Nitric Oxide Generating Nanomedicine for Therapeutic Applications

Nitric oxide (NO), a gaseous transmitter extensively present in the human body, regulates vascular relaxation, immune response, inflammation, neurotransmission, and other crucial functions. Nitrite donors have been used clinically to treat angina, heart failure, pulmonary hypertension, and erectile dysfunction. Based on NO's vast biological functions, it further can treat tumors, bacteria/biofilms and other infections, wound healing, eye diseases, and osteoporosis. However, delivering NO is challenging due to uncontrolled blood circulation release and a half-life of under five seconds. With advanced biotechnology and the development of nanomedicine, NO donors packaged with multifunctional nanocarriers by physically embedding or chemically conjugating have been reported to show improved therapeutic efficacy and reduced side effects. Herein, we review and discuss recent applications of NO nanomedicines, their therapeutic mechanisms, and the challenges of NO nanomedicines for future scientific studies and clinical applications. As NO enables the inhibition of the replication of DNA and RNA in infectious microbes, including COVID-19 coronaviruses and malaria parasites, we highlight the potential of NO nanomedicines for antipandemic efforts. This review aims to provide deep insights and practical hints into design strategies and applications of NO nanomedicines.

Two-dimensional porous vermiculite-based nanocatalysts for synergetic catalytic therapy

This study reports an ultrasound-mediated and two-dimensional (2D) porous vermiculite nanosheets (VMT NSs)-based nanocatalyst platform (Arg@VMT@PDA-PEG) that synergistically harnessed the Fenton reaction-based chemodynamic therapy (CDT), 2D semiconductor-based sonodynamic therapy (SDT) and nitric oxide (NO)-based gas therapy for combination cancer therapy. The tumor microenvironment responsive degradation of polydopamine (PDA) shell could not only prevent L-Arg, a NO donor, leakage during blood circulation, but also selectively release the active sites of VMT NSs for catalytic reactions in tumor cells. Additionally, the Fenton reactions mediated by the abundant Fe²⁺/Fe³⁺ in VMT NSs could efficiently produce ·OH and consume glutathione (GSH) for CDT. Moreover, the reactive oxygen species (ROS, ·OH and ·O₂^-) produced by ultrasound-triggered Arg@VMT@PDA-PEG could not only execute SDT but also oxidize L-Arg to NO for synergetic gas therapy. The results show that the transformation of ROS to NO can enhance curative efficacy owing to the ability of NO with much longer life-time in freely diffusing into cells from intercellular space. This biodegradable Arg@VMT@PDA-PEG nanocatalytic platform integrating three different catalytic reactions provides a new therapeutic paradigm for combination cancer therapy.

Clusterbody Enables Flow Sorting-Assisted Single-Cell Mass Spectrometry Analysis for Identifying Reversal Agent of Chemoresistance

Identifying effective reversal agents overcoming multidrug resistance with causal mechanisms from an efflux pump protein is of vital importance for enhanced tumor chemotherapy in clinic. To achieve this end, we construct a metal cluster-based probe, named clusterbody, to develop flow sorting-assisted single-cell mass spectrometry analysis. This clusterbody synthesized by biomimetic mineralization possesses an antibody-like property to selectively recognize an efflux pump protein. The intrinsic red fluorescence emission of the clusterbody facilitates fluorescence-activated high-throughput cell sorting of subpopulations with different multidrug resistance levels. Furthermore, based on the accurate formula of the clusterbody, the corresponding protein abundance at the single-cell level is determined through detecting gold content via precise signal amplification by laser ablation inductively coupled plasma mass spectrometry. Therefore, the effect of reversal agent treatment overcoming multidrug resistance is evaluated in a quantitative manner. This work opens a new avenue to identify reversal agents, shedding light on developing combined or synergetic tumor therapy.

Gold nanoplatform for near-infrared light-activated radio-photothermal gas therapy in breast cancer

Although radiotherapy is one of the most common treatments for triple-negative breast cancer (TNBC), it frequently has unsatisfactory therapeutic outcomes due to the radiation resistance of tumor tissues. Therefore, a synergistic strategy is urgently needed to increase therapeutic responses and prolong patient survival. Herein, we constructed gold nanocages (GNCs) loaded with a hyperpyrexia-sensitive nitric oxide (NO) donor (thiolate cupferron) to integrate extrinsic radiosensitization, local photothermal therapy, and near-infrared-activated NO gas therapy. The resulting nanoplatform (GNCs@NO) showed a high photothermal conversion efficiency, which induced the death of cancer cells and facilitated rapid NO release in tumor tissues. The radiosensitizing efficacy of GNCs@NO was further demonstrated in vitro and in vivo. Importantly, the released NO reacted with the reactive oxide species induced by radiotherapy to produce more toxic reactive nitrogen species, exerting a synergistic effect to improve anticancer efficacy. Thus, GNCs@NO demonstrated excellent effects as a combination therapy with few adverse effects. Our work proposes a promising nanoplatform for the radio/photothermal/gas treatment of TNBC.

Research Progress of Nanomedicine-Based Mild Photothermal Therapy in Tumor

With the booming development of nanomedicine, mild photothermal therapy (mPTT, 42-45°C) has exhibited promising potential in tumor therapy. Compared with traditional PTT (>50°C), mPTT has less side effects and better biological effects conducive to tumor treatment, such as loosening the dense structure in tumor tissues, enhancing blood perfusion, and improving the immunosuppressive microenvironment. However, such a relatively low temperature cannot allow mPTT to completely eradicate tumors, and therefore, substantial efforts have been conducted to optimize the application of mPTT in tumor therapy. This review extensively summarizes the latest advances of mPTT, including two sections: (1) taking mPTT as a leading role to maximize its effect by blocking the cell defense mechanisms, and (2) regarding mPTT as a supporting role to assist other therapies to achieve synergistic antitumor curative effect. Meanwhile, the special characteristics and imaging capabilities of nanoplatforms applied in various therapies are discussed. At last, this paper puts forward the bottlenecks and challenges in the current research path of mPTT, and possible solutions and research directions in future are proposed correspondingly.

Self-Powered, Implantable, and Wirelessly Controlled NO Generation System for Intracranial Neuroglioma Therapy

Gas therapy is an emerging technology for improving cancer therapy with high efficiency and low side effects. However, due to the existence of the gatekeeper of the blood-brain barrier (BBB) and the limited availability of current drug delivery systems, there still have been no reports on gas therapy for intracranial neuroglioma. Herein, an integrated, self-powered, and wirelessly controlled gas-therapy system is reported, which is composed of a self-powered triboelectric nanogenerator (TENG) and an implantable nitric oxide (NO) releasing device for intracranial neuroglioma therapy. In the system, the patient self-driven TENG converts the mechanical energy of body movements into electricity as a sustainable and self-controlled power source. When delivering energy to light a light-emitting diode in the implantable NO releasing device via wireless control, the encapsulated NO donor s-nitrosoglutathione (GSNO) can generate NO gas to locally kill the glioma cells. The efficacy of the proof-of-concept system in subcutaneous 4T1 breast cancer model in mice and intracranial glioblastoma multiforme in rats is verified. This self-powered gas-therapy system has great potential to be an effective adjuvant treatment modality to inhibit tumor growth, relapse, and invasion via teletherapy.

Recent progress in nitric oxide-generating nanomedicine for cancer therapy

Nitric oxide (NO) is an endogenous, multipotent biological signaling molecule that participates in several physiological processes. Recently, exogenous supplementation of tumor tissues with NO has emerged as a potential anticancer therapy. In particular, it induces synergistic effects with other conventional therapies (such as chemo-, radio-, and photodynamic therapies) by regulating the activity of P-glycoprotein, acting as a vascular relaxant to relieve tumor hypoxia, and participating in the metabolism of reactive oxygen species. However, NO is highly reactive, and its half-life is relatively short after generation. Meanwhile, NO-induced anticancer activity is dose-dependent. Therefore, the targeted delivery of NO to the tumor is required for better therapeutic effects. In the past decade, NO-generating nanomedicines (NONs), which enable sustained and specific NO release in tumor tissues, have been developed for enhanced cancer therapy. This review describes the recent efforts and preclinical achievements in the development of NON-based cancer therapies. The chemical structures employed in the fabrication of NONs are summarized, and the strategies involved in NON-based cancer therapies are elaborated.

Doxorubicin hydrochloride and L-arginine co-loaded nanovesicle for drug resistance reversal stimulated by near-infrared light

Drug resistance is accountable for the inadequate outcome of chemotherapy in clinics. The newly emerging role of nitric oxide (NO) to conquer drug resistance has been recognized as a potential strategy. However, it remains a great challenge to realize targeted delivery as well as accurate release of NO at desired sites. Herein, we developed a PEGylated indocyanine green (mPEG-ICG) integrated nanovesicle system (PIDA) to simultaneously load doxorubicin hydrochloride (DOX⋅HCl) and the NO donor L-arginine (L-Arg), which can produce NO triggered by NIR light irradiation and exert multimodal therapy to sensitize drug-resistant cancers. Upon 808 nm irradiation, the NO released from PIDA led to a decrease in mitochondrial membrane potential, an increase in ROS and significant ATP depletion in K562/ADR cells, thus inhibiting cell growth and resolving the problem of drug resistance. Consequently, the in vivo experiment on K562/ADR-bearing nude mice indicated that PIDA nanovesicles achieved significant anticancer efficacy with a tumor inhibition rate of 80.8%. Above all, PIDA nanovesicles offer guidance for designing nanoplatforms for drug-resistant cancer treatment.

Opportunities for Nitric Oxide in Potentiating Cancer Immunotherapy

Despite nearly 30 years of development and recent highlights of nitric oxide (NO) donors and NO delivery systems in anticancer therapy, the limited understanding of exogenous NO's effects on the immune system has prevented their advancement into clinical use. In particular, the effects of exogenously delivered NO differing from that of endogenous NO has obscured how the potential and functions of NO in anticancer therapy may be estimated and exploited despite the accumulating evidence of NO's cancer therapy-potentiating effects on the immune system. After introducing their fundamentals and characteristics, this review discusses the current mechanistic understanding of NO donors and delivery systems in modulating the immunogenicity of cancer cells as well as the differentiation and functions of innate and adaptive immune cells. Lastly, the potential for the complex modulatory effects of NO with the immune system to be leveraged for therapeutic applications is discussed in the context of recent advancements in the implementation of NO delivery systems for anticancer immunotherapy applications. SIGNIFICANCE STATEMENT: Despite a 30-year history and recent highlights of nitric oxide (NO) donors and delivery systems as anticancer therapeutics, their clinical translation has been limited. Increasing evidence of the complex interactions between NO and the immune system has revealed both the potential and hurdles in their clinical translation. This review summarizes the effects of exogenous NO on cancer and immune cells in vitro and elaborates these effects in the context of recent reports exploiting NO delivery systems in vivo in cancer therapy applications.

Nitric oxide-mediated regulation of mitochondrial protective autophagy for enhanced chemodynamic therapy based on mesoporous Mo-doped Cu9S5 nanozymes

The depletion of reactive oxygen species (ROS) by glutathione (GSH) and oxidative stress induced protective autophagy severely impaired the therapeutic effect of chemodynamic therapy (CDT). Therefore, how to construct a CDT treatment nanosystem with high yield and full utilization of ROS in tumor site is the main issue of CDT. Herein, a multifunctional cascade bioreactor based on mesoporous Mo-doped Cu₉S₅ (m-MCS) nanozymes loaded with L-Arginine (LA), abbreviated as m-MCS@LA, is constructed for realizing enhanced CDT promoted by ultrasound (US) triggered gas therapy. The m-MCS based on the catalytic performance of multivalent metal ions, which were served as nanozymes, exhibit enhanced Fenton-like and glutathione (GSH) peroxidase-like activities in comparison to Cu₉S₅ nanoparticles without Mo-doping. Once placed in tumor microenvironment (TME), the existence of redox couples (Cu⁺/Cu²⁺ and Mo⁴⁺/Mo⁶⁺) in m-MCS enabled it to react with hydrogen peroxide (H₂O₂) to generate ·OH for achieving CDT effect via Fenton-like reaction. Meanwhile, m-MCS could consume overexpressed GSH in tumor microenvironment (TME) to alleviate antioxidant capability for enhancing CDT effect. Moreover, m-MCS with mesoporous structure could be employed as the carrier to load natural nitric oxide (NO) donor LA. US as the excitation source with high tissue penetration can trigger m-MCS@LA to produce NO. As the gas transmitter with physiological functions, NO could play dual roles to kill cancer cells through gas therapy directly, and enhance CDT effect by inhibiting protective autophagy simultaneously. As a result, this US-triggered and NO-mediated synergetic cancer chemodynamic/gas therapy based on m-MCS@LA NPs can effectively eliminate primary tumor and achieved tumor-specific treatment, which provide a possible strategy for developing more effective CDT in future practical applications. STATEMENT OF SIGNIFICANCE: The depletion of reactive oxygen species (ROS) by glutathione (GSH) and oxidative stress induced protective autophagy severely impaired the therapeutic effect of chemodynamic therapy (CDT). Herein, a multifunctional cascade bioreactor based on mesoporous Mo-doped Cu₉S₅ (m-MCS) nanozymes loaded with L-Arginine (m-MCS@LA) is constructed for realizing enhanced CDT promoted by ultrasound (US) triggered gas therapy. The m-MCS with double redox couples presents the enhanced enzyme-like activities to perform cascade reactions for reducing GSH and generating ROS. LA loaded by m-MCS can produce NO triggered by US to inhibit the mitochondria protective autophagy for reactivating mitochondria involved apoptosis pathway. The US-triggered and NO-mediated CDT based on m-MCS@LA can effectively eliminate primary tumor through the high yield and full utilization of ROS.

Nitric oxide-containing supramolecular polypeptide nanomedicine based on [2]biphenyl-extended-pillar[6]arenes for drug resistance reversal

A kind of supramolecular polypeptide nanomedicine (BPC/DOX-ICG) was constructed with an anionic water-soluble [2]biphenyl-extended-pillar[6]arene (AWBpP6), and pyridinium-terminal- and S-nitrosothiol (SNO)-modified polypeptide (PPNC) via host-guest interactions to co-deliver doxorubicin (DOX) and indocyanine green (ICG) for drug resistance reversal. Upon near-infrared (NIR) irradiation, the NO generation could down-regulate the P-glycoprotein (P-gp) expression level to reverse multidrug resistance (MDR). Subsequently, the resulting reverse MDR could sensitize the free DOX and assist photothermal therapy (PTT) to enhance the tumoricidal potential. This supramolecular polypeptide nanomedicine provides an effective strategy for the multimodal synergistic therapies of photothermal therapy, NO generation therapy, and chemotherapy (i.e., PTT-NO-CT) to overcome MDR.

Tumor microenvironment responsive polypeptide-based supramolecular nanoprodrugs for combination therapy

Tumor microenvironment responsive nanomedicine has drawn considerable attention for combination therapy, but still remains a significant challenge for less side effects and enhanced anti-tumor efficiency. Herein, we develop a pH/ROS dual-responsive supramolecular polypeptide nanoprodrug (PFW-DOX/GOD) by using pillar[5]arene-based host-guest strategy for combined glucose degradation, chemodynamic therapy (CDT), and chemotherapy (CT). The PFW-DOX/GOD consists of a pH-responsive ferrocene/pillar[5]arene-containing polypeptide, a ROS-responsive polyprodrug, and encapsulated glucose oxidase (GOD). Upon into intracellular acidic environment, PFW-DOX/GOD exhibits rapid pH-triggered disassembly behavior. Simultaneously, the released GOD can catalyze intratumoral glucose into massive H₂O₂, which are further converted into highly toxic hydroxyl radicals (•OH) by the catalysis of ferrocene via the Fenton reaction. Thereafter, induced by the ROS-responsive cleavage of thioketal linkage, the conjugated DOX prodrug was released and activated. The combined glucose degradation, chemodynamic therapy (CDT), and chemotherapy (CT) of PFW-DOX/GOD present anti-tumor effect with 96% of tumor inhibitory rate (TIR). Therefore, such tumor microenvironment-responsive supramolecular polypeptide nanoprodrugs represent a potential candidate for combination therapy with minimal side effects. STATEMENT OF SIGNIFICANCE: In this work, a tumor microenvironment-responsive supramolecular polypeptide nanoprodrug (PFW-DOX/GOD) was prepared via pillar[5]arene-based host-guest interactions, and presented low side effects and high tumor accumulation owing to the diameters of about 200 nm and surface PEG segment. After pH-responsive release of GOD in the intracellular acidic environment, the cascade catalytic reactions including GOD-catalyzed degradation of intratumoral glucose and Fenton reaction, effectively happened to generate •OH for chemodynamic therapy (CDT), which subsequently induced the cleavage of thioketal linkage to activate free DOX for chemotherapy (CT). Collectively, this supramolecular polypeptide nanoprodrugs provide a promising strategy for combination therapy with synergetic anti-tumor effect.

The Advancement of Gas-Generating Nanoplatforms in Biomedical Fields: Current Frontiers and Future Perspectives

Diverse gases (NO, CO, H₂ S, H₂ , etc.) have been widely applied in the medical intervention of various diseases, including cancer, cardiovascular disease, ischemia-reperfusion injury, bacterial infection, etc., attributing to their inherent biomedical activities. Although many gases have many biomedical activities, their clinical use is still limited due to the rapid and free diffusion behavior of these gases molecules, which may cause potential side effects and/or ineffective treatment. Gas-generating nanoplatforms (GGNs) are effective strategies to address the aforementioned challenges of gas therapy by preventing gas production or release at nonspecific sites, enhancing GGNs accumulation at targeted sites, and controlling gas release in response to exogenous (UV, NIR, US, etc.) or endogenous (H₂ O₂ , GSH, pH, etc.) stimuli at the lesion site, further maintaining gas concentration within the effective range and achieving the purpose of disease treatment. This review comprehensively summarizes the advancements of "state-of-the-art" GGNs in the recent three years, with emphasis on the composition, structure, preparation process, and gas release mechanism of the nanocarriers. Furthermore, the therapeutic effects and limitations of GGNs in preclinical studies using cell/animal models are discussed. Overall, this review enlightens the further development of this field and promotes the clinical transformation of gas therapy.

Recent advances in anti-multidrug resistance for nano-drug delivery system

Chemotherapy for tumors occasionally results in drug resistance, which is the major reason for the treatment failure. Higher drug doses could improve the therapeutic effect, but higher toxicity limits the further treatment. For overcoming drug resistance, functional nano-drug delivery system (NDDS) has been explored to sensitize the anticancer drugs and decrease its side effects, which are applied in combating multidrug resistance (MDR) via a variety of mechanisms including bypassing drug efflux, controlling drug release, and disturbing metabolism. This review starts with a brief report on the major MDR causes. Furthermore, we searched the papers from NDDS and introduced the recent advances in sensitizing the chemotherapeutic drugs against MDR tumors. Finally, we concluded that the NDDS was based on several mechanisms, and we looked forward to the future in this field.

Glucose-Responsive ZIF-8 Nanocomposites for Targeted Cancer Therapy through Combining Starvation with Stimulus-Responsive Nitric Oxide Synergistic Treatment

With the rapid development of nanomedicine, low side effects and high-efficiency green antitumor approaches have attracted great attention. Herein, we report a strategy for the in situ synthesis of graphene oxide@zeolitic imidazolate framework-8 (GOx@ZIF-8) composite nanoparticles with high catalytic efficiency, under mild conditions by adding GOx molecules to the precursor of ZIF-8, and use them as a carrier to achieve efficient loading of l-Arg. In addition. folic-acid-conjugated bovine serum albumin (FA-BSA) has been used to engineer the surface of GOx@ZIF-8-l-Arg composite nanoparticles to enhance their specific recognition of tumor cells. With the high glucose level and low pH in the tumor intracellular environment, FA-BSA/GOx@ZIF-8-l-Arg rapidly consumed the intracellular glucose and produced H₂O₂, which profusely deteriorated the intracellular environment. Subsequently, a large amount of l-Arg was continuously released from the nanoparticles, reacting with H₂O₂ to continuously produce a high concentration of nitric oxide (NO), which further damaged the tumor cells. The FA-BSA/GOx@ZIF-8-l-Arg composite nanoparticles were cleverly designed to kill cancer cells efficiently through a starvation-NO synergistic process. This emerging green antitumor method has a promising application prospect in targeted therapy for the efficient clearance of cancers.

Procyanidins and Their Therapeutic Potential against Oral Diseases

Procyanidins, as a kind of dietary flavonoid, have excellent pharmacological properties, such as antioxidant, antibacterial, anti-inflammatory and anti-tumor properties, and so they can be used to treat various diseases, including Alzheimer’s disease, diabetes, rheumatoid arthritis, tumors, and obesity. Given the low bioavailability of procyanidins, great efforts have been made in drug delivery systems to address their limited use. Nowadays, the heavy burden of oral diseases such as dental caries, periodontitis, endodontic infections, etc., and their consequences on the patients’ quality of life indicate a strong need for developing effective therapies. Recent years, plenty of efforts are being made to develop more effective treatments. Therefore, this review summarized the latest researches on versatile effects and enhanced bioavailability of procyanidins resulting from innovative drug delivery systems, particularly focused on its potential against oral diseases.

pH/ROS dual-responsive supramolecular polypeptide prodrug nanomedicine based on host-guest recognition for cancer therapy

Supramolecular nanomedicine assembly combined with polypeptide prodrug could become a powerful strategy to minimize drug leakage in blood circulation and trigger sufficient drug release at tumor tissue. Here, we developed a charge-reversal amphiphilic pillar[5]arene-modified polypeptide (P5-PLL-DMA), and reactive oxygen species (ROS)-sensitive polypeptide prodrug (P-PLL-DOX) including a ROS-cleavable thioketal (TK) linker between doxorubicin (DOX) and poly(_L-lysine) (PLL), which could assemble via pillar[5]arene host-guest recognition, and further encapsulate chlorin e6 (Ce6) to obtain a supramolecular polypeptide prodrug (SPP-DOX/Ce6). The chemical conjugation to load drugs of DOX and the negatively charge of SPP-DOX/Ce6 could prevent premature drug leakage, and reduce undesirable interaction with serum proteins to enhance stability under physiological conditions (pH 7.4). Simultaneously, the carried charge of SPP-DOX/Ce6 reversed from negative to positive could effectively enhance the cellular internalization for efficient DOX delivery under acidic tumor microenvironment (pH 6.5). Upon 660 nm near-infrared light (NIR) irradiation, the ROS generated by encapsulated Ce6 rapidly cleaved the TK linker to release activated DOX, inducing the tumor-specific drug delivery. This intelligent supramolecular polypeptide prodrug based on pillar[5]arene host-guest recognition represents new avenues to develop stimulus responsive prodrug for enhanced cancer therapy with minimized the side effect. STATEMENT OF SIGNIFICANCE: In this work, a pH/ROS dual-sensitive supramolecular polypeptide prodrug (SPP-DOX/Ce6) was developed to minimize drug leakage in blood circulation and trigger sufficient drug release at tumor tissue. The chemical conjugation to load drugs of DOX via a ROS-cleavable thioketal (TK) linker and the distinctive charge-reversal capacity of SPP-DOX/Ce6 significantly enhances the stability under physiological conditions (pH 7.4), while facilitates cellular uptake at tumor site (pH 6.8). Upon 660 nm near-infrared light (NIR) irradiation, the ROS generated by encapsulated Ce6 induces the rapid cleavage of TK linker to release activated DOX, achieving a tumor-specific drug delivery. This intelligent supramolecular polypeptide prodrug SPP-DOX/Ce6 provides an effective strategy to construct stimulus responsive prodrug for enhanced cancer therapy.

Recent Progress of Novel Nanotechnology Challenging the Multidrug Resistance of Cancer

Multidrug resistance (MDR) of tumors is one of the clinical direct reasons for chemotherapy failure. MDR directly leads to tumor recurrence and metastasis, with extremely grievous mortality. Engineering a novel nano-delivery system for the treatment of MDR tumors has become an important part of nanotechnology. Herein, this review will take those different mechanisms of MDR as the classification standards and systematically summarize the advances in nanotechnology targeting different mechanisms of MDR in recent years. However, it still needs to be seriously considered that there are still some thorny problems in the application of the nano-delivery system against MDR tumors, including the excessive utilization of carrier materials, low drug-loading capacity, relatively narrow targeting mechanism, and so on. It is hoped that through the continuous development of nanotechnology, nano-delivery systems with more universal uses and a simpler preparation process can be obtained, for achieving the goal of defeating cancer MDR and accelerating clinical transformation.

Near-infrared light-triggered nano-prodrug for cancer gas therapy

Gas therapy (GT) has attracted increasing attention in recent years as a new cancer treatment method with favorable therapeutic efficacy and reduced side effects. Several gas molecules, such as nitric oxide (NO), carbon monoxide (CO), hydrogen (H2), hydrogen sulfide (H2S) and sulfur dioxide (SO2), have been employed to treat cancers by directly killing tumor cells, enhancing drug accumulation in tumors or sensitizing tumor cells to chemotherapy, photodynamic therapy or radiotherapy. Despite the great progress of gas therapy, most gas molecules are prone to nonspecific distribution when administered systemically, resulting in strong toxicity to normal tissues. Therefore, how to deliver and release gas molecules to targeted tissues on demand is the main issue to be considered before clinical applications of gas therapy. As a specific and noninvasive stimulus with deep penetration, near-infrared (NIR) light has been widely used to trigger the cleavage and release of gas from nano-prodrugs via photothermal or photodynamic effects, achieving the on-demand release of gas molecules with high controllability. In this review, we will summarize the recent progress in cancer gas therapy triggered by NIR light. Furthermore, the prospects and challenges in this field are presented, with the hope for ongoing development.

Electron-acceptor density adjustments for preparation conjugated polymers with NIR-II absorption and brighter NIR-II fluorescence and 1064 nm active photothermal/gas therapy

Designing conjugated polymers (CPs) with both efficient second near-infrared wavelength (NIR-II) fluorescence and NIR-II photothermal therapy performance remains a huge challenge, as the introduction of excessively strong electron donor and acceptor units significantly increase non-radiative decay. Herein, we describe an "electron acceptor density adjustment" strategy to address this problem, since a lower electron acceptor density in the conjugated polymer backbone can enhance the radiative rate constant and improve NIR-II fluorescence brightness. We used quaterthiophene (4T) with four repeated thiophene chain units and bithiophene (2 TC) modified with long alkyl side chains to reduce the electron acceptor density in the conjugated polymer backbone. The resultant 1064 nm absorption polymer, TTQ-2TC-4T displayed approximately 7.30-folds enhancement in NIR-II emission intensity compared to that of undoped TTQ-1T at the same mass concentration in toluene solution. Furthermore nanoparticles (TTQ-MnCO NPs) based on TTQ-2TC-4T and CO donors (Mn₂(CO)₁₀) were developed to realize NIR-II FI-guided 1064 nm laser-triggered NIR-II PTT/Gas synergistic therapy. The TTQ-MnCO NPs nanoparticles exhibited high photothermal conversion efficiency (η) of 44.43% at 1064 nm and high specific NIR-II fluorescence imaging of the cerebral vasculature of live mice. The in vivo results demonstrate that TTQ-MnCO NPs nanoparticles have excellent PTT/Gas synergistic therapeutic effects in MCF-7 tumor-bearing mice under 1064 nm laser irradiation. This study provides a new approach for optimizing both NIR-II fluorescence and NIR-II photothermal performance of NIR-II absorption conjugated polymers.

Polydopamine-drug conjugate nanocomposites based on ZIF-8 for targeted cancer photothermal-chemotherapy

Stimuli-responsive prodrug-based nanoplatform with synergistic antitumor activity is of central importance to the development of promising nanomedicines for cancer therapy. Here, we describe a polydopamine-drug conjugate nanocomposite (ZP-PDA-DOX) with targeted cancer photothermal-chemotherapy (PTT-CT), which constructed by a gradual copolymerization of dopamine (DA) and pH-sensitive dopamine-derived prodrug (DA-DOX) into the porous channels of zeolite imidazolate frameworks-8 (ZIF-8), followed by PEGylation with amino-terminated folic acid-polyethylene glycol (NH₂ -PEG-FA) to acquire the high biocompatibility, specificity, and excellent tumor-targeting property. The incorporation of polydopamine strengthened the stability and dispersion of ZIF-8, and also conferred photothermal conversion effect. In the tumor acidic microenvironment, the acid-labile hydrazone linker of DA-DOX and ZIF-8 promptly degraded to release activated DOX. Moreover, the generated hyperthermia due to the high photothermal conversion efficiency of PDA component could accelerate drug release, and simultaneously thermally ablate tumor tissue to maximize the DOX-induced CT, which could also assist PTT to eradicate tumor cells. This study provides a promising strategy for targeted cancer PTT-CT with synergistic anti-tumor effect.

Cross-linking of S-nitrosothiolated AIEgens inside cancer cells to monitor NO release and reverse chemo-resistance

Nitric oxide (NO)-releasing platforms have been demonstrated as promising approaches for the reversal of multidrug resistance (MDR) in cancer cells due to the suppression of P-glycoprotein (P-gp). However, the non-specific systemic release of NO and difficulty in estimating the precise NO amount in target sites hindered their translational applications. Traditional bioimaging techniques which are responsive to NO molecules cannot distinguish between exogenous and endogenous NO. Herein we introduce S-nitrosothiol-functionalized tetraphenylethene (TPE-RSNO) to specifically monitor exogenous NO release and synergistically reverse MDR. TPE-RSNO can specifically respond to NO release and visualize NO delivery with fluorescence in living cells. Moreover, the elevated reactive oxygen species (ROS) in cancer cells triggered rapid NO release to reduce P-gp and thus synergistically increase the therapeutic effect of doxorubicin (DOX).

Stimuli Responsive Nitric Oxide-Based Nanomedicine for Synergistic Therapy

Gas therapy has received widespread attention from the medical community as an emerging and promising therapeutic approach to cancer treatment. Among all gas molecules, nitric oxide (NO) was the first one to be applied in the biomedical field for its intriguing properties and unique anti-tumor mechanisms which have become a research hotspot in recent years. Despite the great progress of NO in cancer therapy, the non-specific distribution of NO in vivo and its side effects on normal tissue at high concentrations have impaired its clinical application. Therefore, it is important to develop facile NO-based nanomedicines to achieve the on-demand release of NO in tumor tissue while avoiding the leakage of NO in normal tissue, which could enhance therapeutic efficacy and reduce side effects at the same time. In recent years, numerous studies have reported the design and development of NO-based nanomedicines which were triggered by exogenous stimulus (light, ultrasound, X-ray) or tumor endogenous signals (glutathione, weak acid, glucose). In this review, we summarized the design principles and release behaviors of NO-based nanomedicines upon various stimuli and their applications in synergistic cancer therapy. We also discuss the anti-tumor mechanisms of NO-based nanomedicines in vivo for enhanced cancer therapy. Moreover, we discuss the existing challenges and further perspectives in this field in the aim of furthering its development.

Nanomedicine potentiates mild photothermal therapy for tumor ablation

The booming photothermal therapy (PTT) has achieved great progress in non-invasive oncotherapy, and paves a novel way for clinical oncotherapy. Of note, mild temperature PTT (mPTT) of 42–45 °C could avoid treatment bottleneck of the traditional PTT, including nonspecific injury to normal tissues, vasculature and host antitumor immunity. However, cancer cells can resist mPTT via heat shock response and autophagy, thus leading to insufficient mPTT monotherapy to ablate tumor. To overcome the deficient antitumor efficacy caused by thermo-resistance of cancer cells and mono mPTT, synergistic therapies towards cancer cells have been conducted with mPTT. This review summarizes the recent advances in nanomedicine-potentiated mPTT for cancer treatment, including strategies for enhanced single-mode mPTT and mPTT plus synergistic therapies. Moreover, challenges and prospects for clinical translation of nanomedicine-potentiated mPTT are discussed.

Gas and gas-generating nanoplatforms in cancer therapy

Gas therapy is the usage of certain gases with special therapeutic effects for the treatment of diseases. Hydrogen (H₂), nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H₂S) acting as gas signalling molecules are representative gases in cancer therapy. They act directly on mitochondria or nuclei to lead to cell apoptosis. They can also alleviate immuno-suppression in the tumour microenvironment and promote phenotype conversion of tumour-associated macrophages. Moreover, the combination of gas therapy and other traditional therapy methods can reduce side effects and improve therapeutic efficacy. Here, we discuss the roles of NO, CO, H₂S and H₂ in cancer biology. Considering the rapidly developing nanotechnology, gas-generating nanoplatforms which can achieve targeted delivery and controlled release were also discussed. Finally, we highlight the current challenges and future opportunities of gas-based cancer therapy.

A polydopamine nanomedicine used in photothermal therapy for liver cancer knocks down the anti-cancer target NEDD8-E3 ligase ROC1 (RBX1)

Knocking down the oncogene ROC1 with siRNA inhibits the proliferation of cancer cells by suppressing the Neddylation pathway. However, methods for delivering siRNA in vivo to induce this high anticancer activity with low potential side effects are urgently needed. Herein, a folic acid (FA)-modified polydopamine (PDA) nanomedicine used in photothermal therapy was designed for siRNA delivery. The designed nanovector can undergo photothermal conversion with good biocompatibility. Importantly, this genetic nanomedicine was selectively delivered to liver cancer cells by FA through receptor-mediated endocytosis. Subsequently, the siRNA cargo was released from the PDA nanomedicine into the tumor microenvironment by controlled release triggered by pH. More importantly, the genetic nanomedicine not only inhibited liver cancer cell proliferation but also promoted liver cell apoptosis by slowing ROC1 activity, suppressing the Neddylation pathway, enabling the accumulation of apototic factor ATF4 and DNA damage factor P-H2AX. Combined with photothermal therapy, this genetic nanomedicine showed superior inhibition of the growth of liver cancer in vitro and in vivo. Taken together, the results indicate that this biodegradable nanomedicine exhibits good target recognition, an effective pH response, application potential for genetic therapy, photothermal imaging and treatment of liver cancer. Therefore, this work contributes to the design of a multifunctional nanoplatform that combines genetic therapy and photothermal therapy for the treatment of liver cancer.

Reversing Multidrug Resistance by Inducing Mitochondrial Dysfunction for Enhanced Chemo-Photodynamic Therapy in Tumor

Efficiency of standard chemotherapy is dramatically hindered by intrinsic multidrug resistance (MDR). Recently, to amplify therapeutic efficacy, photodynamic therapy (PDT)-induced mitochondrial dysfunction by decorating targeting moieties on nanocarriers has obtained considerable attention. Nevertheless, low targeting efficiency, complex synthesis routes, and difficulty in releasing contents become the major obstacles in further clinical application. Herein, an ingenious liposomal-based nanomedicine (L@BP) was fabricated by encapsulating a mitochondria-anchored photosensitizer (Cy-Br) and paclitaxel (PTX) for realizing enhanced cooperation therapy. At the cellular level, L@BP could hurdle endosomal traps to localize and implement PDT in mitochondria. Intriguingly, the PDT-induced in situ mitochondrial dysfunction led to intracellular ATP reduction, which triggered the downregulated P-glycoprotein transportation capacity and thus resulted in diminishing the efflux of chemotherapeutic agents and increasing drug uptake by drug-resistant cells. The prepared nanomedicine eminently accumulated in the tumor site and acquired enhanced therapeutic efficiency on PTX-resistant lung cancer cells, which possessed great potential in circumventing MDR tumors.