Mesoporous Polydopamine Carrying Manganese Carbonyl Responds to Tumor Microenvironment for Multimodal Imaging‐Guided Cancer Therapy

Renal Clearable Catalytic 2D Au-Porphyrin Coordination Polymer Augmented Photothermal-Gas Synergistic Cancer Therapy

As a gasotransmitter, carbon monoxide (CO) possesses antitumor activity by reversing the Warburg effect at higher concentrations. The targeted delivery of carbon monoxide-releasing molecules (CORMs) using nanomaterials is an appealing option for CO administration, but how to maintain CO above the threshold concentration in tumor tissue remains a challenge. Herein, a nanozyme-catalyzed cascade reaction is proposed to promote CO release for high-efficacy photothermal therapy (PTT)-combined CO therapy of cancer. A gold-based porphyrinic coordination polymer nanosheet (Au⁰ -Por) is synthesized to serve as a carrier for CORM. It also possesses excellent glucose oxygenase-like activity owing to ultrasmall zero-valent gold atoms on the nanosheet. The catalytically generated H₂ O₂ can efficiently catalyze CORM decomposition, which enables in situ generation of sufficient CO for gas therapy. In vivo, the Au⁰ -Por nanosheets-enhanced photoacoustic imaging (PAI) and fluorescence imaging collectively demonstrate high tumor-targeting efficiency and nanomaterial retention. Proven to have augmented therapeutic efficacy, the nanoplatform can also be easily degraded and excreted through the kidney, indicating good biocompatibility. Thus, the application of rational designed Au⁰ -Por nanosheet with facile approach and biodegradable property to PAI-guided synergistic gas therapy can provide a strategy for the development of biocompatible and highly effective gaseous nanomedicine.

Continuous Spatiotemporal Therapy of A Full-API Nanodrug via Multi-Step Tandem Endogenous Biosynthesis

Nanomedicine holds great promise to enhance cancer therapy. However, low active pharmaceutical ingredient (API) loading content, unpredictable drug release, and potential toxicity from excipients limit their translational capability. We herein report a full-API nanodrug composed of FDA-approved 5-aminolevulinic acid (ALA), human essential element Fe3+, and natural bioactive compound curcumin with an ideal API content and pH-responsive release profile for continuous spatiotemporal cancer therapy achieved by multi-step tandem endogenous biosynthesis. First, ALA enzymatically converts into photosensitizer protoporphyrin IX (PpIX). Afterward, multiple downstream products including carbon monoxide (CO), Fe2+, biliverdin (BV), and bilirubin (BR) are individually biosynthesized through the PpIX-heme-CO/Fe2+/BV-BR metabolic pathway, further cooperating with released Fe3+ and curcumin, ultimately eliciting mitochondria damage, membrane disruption, and intracytoplasmic injury. This work not only provides a paradigm for exploiting diversified metabolites for tumor suppression, but also presents a safe and efficient full-API nanodrug, facilitating the practical translation of nanodrugs.

A pH-Responsive Charge-Convertible Drug Delivery Nanocarrier for Precise Starvation and Chemo Synergistic Oncotherapy

A pH-responsive charge-convertible drug delivery nanocarrier (MSN-TPZ-GOx@ZnO@PAH-PEG-DMMA, abbreviated as MTGZ@PPD) was prepared, which could specifically release hypoxia-activated chemotherapeutic Tirapazamine (TPZ) and glucose oxidase (GOx) in the tumor site for precise starvation and chemo synergistic oncotherapy. Acid-responsive Schiff base structure modified mesoporous silica nanoparticles (MSN) co-load with GOx and TPZ, then link with ZnO quantum dots (QDs). PAH-PEG-DMMA (PPD) polymer makes MTGZ@PPD with biocompatibility and charge-convertible feature. MTGZ@PPD is negatively charged at physiological pH, and the charge reversal of PPD and acidolysis of the Schiff base structure under the acidic tumor microenvironment (TME) induce a positively charged surface, which could potentiate the cell internalization. ZnO QDs could decompose at acidic TME, achieving controllable drug release. GOx could starve the tumor cells and enhance hypoxia level, thus initiates the activation of TPZ to realize synergistic starvation therapy and chemotherapy. This intelligent MTGZ@PPD has shown great potential for starvation and chemo synergistic oncotherapy.

Multifunctional nanoparticle for cancer therapy

Cancer is a complex disease associated with a combination of abnormal physiological process and exhibiting dysfunctions in multiple systems. To provide effective treatment and diagnosis for cancer, current treatment strategies simultaneously focus on various tumor targets. Based on the rapid development of nanotechnology, nanocarriers have been shown to exhibit excellent potential for cancer therapy. Compared with nanoparticles with single functions, multifunctional nanoparticles are believed to be more aggressive and potent in the context of tumor targeting. However, the development of multifunctional nanoparticles is not simply an upgraded version of the original function, but involves a sophisticated system with a proper backbone, optimized modification sites, simple preparation method, and efficient function integration. Despite this, many well-designed multifunctional nanoparticles with promising therapeutic potential have emerged recently. Here, to give a detailed understanding and analyzation of the currently developed multifunctional nanoparticles, their platform structures with organic or inorganic backbones were systemically generalized. We emphasized on the functionalization and modification strategies, which provide additional functions to the nanoparticle. We also discussed the application combination strategies that were involved in the development of nanoformulations with functional crosstalk. This review thus provides an overview of the construction strategies and application advances of multifunctional nanoparticles.

Image-Guided Precision Treatments

Chemotherapy, radiotherapy, and surgery are traditional cancer treatments, which usually produce unpredictable side effects and potential risks to normal healthy organs/tissues. Thus, safe and reliable treatment strategies are urgently required for maximized therapeutic efficiency to lesions and minimized risks to healthy regions. To this end, molecular imaging is responsible to undertake a specific targeting therapy. Besides that, the image guidance as a precision visualized approach for real-time in situ evaluations as well as an intraoperational navigation approach has earned attractive attention in the past decade. Along with the rapid development of multifunctional micro-/nanobiomaterials, versatile cutting-edge and advanced therapy strategies (e.g., thermal therapy, dynamic therapy, gas therapy, etc.) have been achieved and greatly contributed to the image-guided precision treatments in every aspect. Therefore, this chapter aims to discuss about both traditional and advanced cancer treatments and especially to elucidate the important roles that visualized medicine has been playing in the image-guided precision treatments.

Advances in image-guided drug delivery for antibacterial therapy

The emergence of antibiotic-resistant bacterial strains is seriously endangering the global healthcare system. There is an urgent need for combining imaging with therapies to realize the real-time monitoring of pathological condition and treatment progress. It also provides guidance on exploring new medicines and enhance treatment strategies to overcome the antibiotic resistance of existing conventional antibiotics. In this review, we provide a thorough overview of the most advanced image-guided approaches for bacterial diagnosis (e.g., computed tomography imaging, magnetic resonance imaging, photoacoustic imaging, ultrasound imaging, fluorescence imaging, positron emission tomography, single photon emission computed tomography imaging, and multiple imaging), and therapies (e.g., photothermal therapy, photodynamic therapy, chemodynamic therapy, sonodynamic therapy, immunotherapy, and multiple therapies). This review focuses on how to design and fabricate photo-responsive materials for improved image-guided bacterial theranostics applications. We present a potential application of different image-guided modalities for both bacterial diagnosis and therapies with representative examples. Finally, we highlighted the current challenges and future perspectives image-guided approaches for future clinical translation of nano-theranostics in bacterial infections therapies. We envision that this review will provide for future development in image-guided systems for bacterial theranostics applications.

Metal-phenolic networks with ferroptosis to deliver NIR-responsive CO for synergistic therapy

As an endogenous gasotransmitter, CO has achieved tremendous advances in cancer treatment through selectively killing cancer cells. However, the application of CO in tumor immunotherapy has not been reported and the tumor targeting delivery is still a tremendous challenge. Herein, thermosensitive boronic acid group-containing CO prodrug was synthesized and fabricated with tannic acid (TA) and iron (Fe) to form metal-phenolic networks, and then loaded with near-infrared (NIR) photothermal agent IR820 to form FeCO-IR820@Fe^IIITA for combinational therapy of CO and photothermal therapy. Ferroptosis can also be enhanced due to the Fe³⁺ incorporation. After TA reduced Fe³⁺ into Fe²⁺, Fe²⁺ might lead to intracellular Fenton reaction. Furthermore, in combination with CTLA-4 blockade immunotherapy, FeCO-IR820@Fe^IIITA remarkably inhibited breast tumor growth, suppressed the lung metastasis and improved the antitumor immune response. To summarize, FeCO-IR820@Fe^IIITA provides a potential novel option for CO/photothermal/immune synergistic therapy with enhanced ferroptosis through simple compositions and facile synthesis process.

Mesoporous, anisotropic nanostructures from bioinspired polymeric catecholamine neurotransmitters and their potential application as photoacoustic imaging agents

Mesoporous polydopamine (PDA) nanobowls, which can be prepared using Pluronic® F-127, ammonia, and 1,3,5-trimethylbenzene (TMB), are one of the most studied anisotropic nanoparticle systems. However, only limited reports on polymerised analogues polynorepinephrine (PNE) and polyepinephrine (PEP) exist. Herein, we present modifications to a one-pot, soft template method, originally applied to make PDA nanobowls, to fabricate new shape-anisotropic nanoparticles (mesoporous nanospheres or "nano-golf balls" and nanobowls) using PNE and PEP for the first time. These modifications include the use of different oil phases (TMB, toluene and o-xylene) and ammonia concentrations to induce anisotropic growth of PDA, PNE, and PEP particles. Moreover, this work features the application of oddly shaped PDA, PNE, and PEP nanoparticles as intravascular photoacoustic imaging enhancers in Intralipid®-India ink-based tissue-mimicking phantoms. Photoacoustic imaging experiments showed that mesoporous nanobowls exhibit stronger enhancement, in comparison to their mesoporous nano-golf ball and nanoaggregate counterparts. The photoacoustic enhancement also followed the general trend PDA > PNE > PEP due to the differences in the rates of polymerisation of the monomers and the optical absorption of the resulting polymers. Lastly, about two- to four-fold enhancement in photoacoustic signals was observed for the mesoporous nanostructures, when compared to smooth nanospheres and their nano-aggregates. These results suggest that shape manipulation can aid in overcoming the inherently lower performance of PNE and PEP as photoacoustic imaging agents, compared to PDA. Since nanomaterials with mesoporous and anisotropic morphologies have significant, unexplored potential with emerging applications, these results set the groundwork for future studies on photoacoustically active oddly shaped PNE- and PEP-based nanosystems.

Molecularly Targeted Photothermal Ablation of Epidermal Growth Factor Receptor-Expressing Cancer Cells with a Polypyrrole-Iron Oxide-Afatinib Nanocomposite

Simple Summary

In this manuscript, we describe the design and synthesis of a nanocomposite containing afatinib, polypyrrole, and iron oxide (PIA-NC) to molecularly target epidermal growth factor receptor (EGFR)-overexpressing cancer cells for photothermal conversion. In addition to physical and chemical characterization, we also showed that PIA-NC induces selective reactive oxygen species surge and apoptosis in response to sublethal near-infrared light only in EGFR-overexpressing cancer cells, not in EGFR-negative fibroblasts. The work demonstrates the feasibility of photothermal therapy with cellular precision.

Abstract

Near-infrared–photothermal therapy (NIR-PTT) is a potential modality for cancer treatment. Directing photothermal effects specifically to cancer cells may enhance the therapeutic index for the best treatment outcome. While epithelial growth factor receptor (EGFR) is commonly overexpressed/genetically altered in human malignancy, it remains unknown whether targeting EGFR with tyrosine kinase inhibitor (TKI)-conjugated nanoparticles may direct NIR-PTT to cancers with cellular precision. In the present study, we tested this possibility through the fabrication of a polypyrrole–iron oxide–afatinib nanocomposite (PIA-NC). In the PIA-NC, a biocompatible and photothermally conductive polymer (polypyrrole) was conjugated to a TKI (afatinib) that binds to overexpressed wild-type EGFR without overt cytotoxicity. A Fenton catalyst (iron oxide) was further encapsulated in the NC to drive the intracellular ROS surge upon heat activation. Diverse physical and chemical characterization experiments were conducted. Particle internalization, cytotoxicity, ROS production, and apoptosis in EGFR-positive and -negative cell lines were investigated in the presence and absence of NIR. We found that the PIA-NCs were stable with a size of 243 nm and a zeta potential of +35 mV. These PIA-NCs were readily internalized close to the cell membrane by all types of cells used in the study. The Fourier transform infrared spectra showed 3295 cm⁻¹ peaks; substantial O–H stretching was seen, with significant C=C stretching at 1637 cm⁻¹; and a modest appearance of C–O–H bending at 1444 cm⁻¹ confirmed the chemical conjugation of afatinib but not iron oxide to the NC. At a NIR-PTT energy level that has a minimal cytotoxic effect, PIA-NC significantly sensitizes EGFR-overexpressing A549 lung cancer cells to NIR-PTT-induced cytotoxicity at a rate of 70%, but in EGFR-negative 3T3 fibroblasts the rate was 30%. Within 1 min of NIR-PTT, a surge of intracellular ROS was found in PIA-NC-treated A549 cells. This was followed by early induction of cellular apoptosis for 54 ± 0.081% of A549 cells. The number of viable cells was less than a quarter of a percent. Viability levels of A549 cells that had been treated with NIR or PIA were only 50 ± 0.216% and 80 ± 0.216%, respectively. Only 10 ± 0.816% of NIH3T3 cells had undergone necrosis, meaning that 90 ± 0.124% were alive. Viability levels were 65 ± 0.081% and 81 ± 0.2%, respectively, when only NIR and PIA were used. PIA binding was effective against A549 cells but not against NIH3T3 cells. The outcome revealed that higher levels of NC + NIR exposure caused cancer cells to produce more ROS. In summary, our findings proved that a molecularly targeted NC provides an orchestrated platform for cancer cell-specific delivery of NIR-PTT. The geometric proximity design indicates a novel approach to minimizing the off-target biological effects of NIR-PTT. The potential of PIA-NC to be further developed into real-world application warrants further investigation.

Protein Binding Nanoparticles as an Integrated Platform for Cancer Diagnosis and Treatment

Smart nanomaterials constitute a new approach toward safer and more effective combined anti-cancer immunotherapy. In this study, polydopamine-multiprotein conjugates (DmPCs) that can be used for targeted delivery of multiple proteins to cells, realize imaging and combine the advantages of multiple treatment methods (photothermal therapy, chemodynamic therapy, and immunotherapy) can be synthesized and characterized. Proteins, as biological agents, are frequently used in this context, given their low toxicity in vivo. To overcome protein instability and short half-life in vivo, the use of several proteins in combination with selected nanomaterials to treat patients with melanoma is proposed. In addition to the synthesis and characterization of protein-bound nanoparticles, it is further demonstrated that several proteins can be efficiently delivered to tumor sites. DmPCs have a wide range of potential adaptability, which provides new opportunities for proteins in the field of treatment and imaging.

Multistage-Responsive Gene Editing to Sensitize Ion-Interference Enhanced Carbon Monoxide Gas Therapy

As a promising therapeutic modality targeting cancer, gas therapy still faces critical challenges, especially in enhancing therapeutic efficacy and avoiding gas poisoning risks. Here, a pH/glutathione (GSH) dual stimuli-responsive CRISPR/Cas9 gene-editing nanoplatform combined with calcium-enhanced CO gas therapy for precise anticancer therapy, is established. In the tumor microenvironment (TME), the fast biodegradation of the CaCO₃ layer via pH-induced hydrolyzation allows glucose oxidase (GOx) to catalyze glucose for H₂ O₂ production, which further reacts with manganese carbonyl (MnCO) and achieves the precise release of CO gas. Simultaneously, in situ Ca²⁺ overload from CaCO₃ degradation disturbs mitochondrial Ca²⁺ homeostasis, resulting in Ca²⁺ -driven reactive oxygen species (ROS) formation and subsequent mitochondrial apoptosis signaling pathway activation. Subsequently, by GSH-induced cleavage of a disulfide bond, the released Cas9/sgRNA (RNP) can achieve nuclear factor E2-related factor 2 (Nrf2) gene ablation to sensitize gas therapy by interfering with ROS signaling. This therapeutic modality endows codelivery of CRISPR, ions, and gas with smart control features, which demonstrates great potential for future clinical applications in precise nanomedicine.

Therapeutic gas-releasing nanomedicines with controlled release: Advances and perspectives

Nanoparticle-based drug delivery has become one of the most popular approaches for maximising drug therapeutic potentials. With the notable improvements, a greater challenge hinges on the formulation of gasotransmitters with unique challenges that are not met in liquid and solid active ingredients. Gas molecules upon release from formulations for therapeutic purposes have not really been discussed extensively. Herein, we take a critical look at four key gasotransmitters, that is, carbon monoxide (CO), nitric oxide (NO), hydrogen sulphide (H2S) and sulphur dioxide (SO2), their possible modification into prodrugs known as gas-releasing molecules (GRMs), and their release from GRMs. Different nanosystems and their mediatory roles for efficient shuttling, targeting and release of these therapeutic gases are also reviewed extensively. This review thoroughly looks at the diverse ways in which these GRM prodrugs in delivery nanosystems are designed to respond to intrinsic and extrinsic stimuli for sustained release. In this review, we seek to provide a succinct summary for the development of therapeutic gases into potent prodrugs that can be adapted in nanomedicine for potential clinical use.

Osteoimmunity-Regulating Biomimetically Hierarchical Scaffold for Augmented Bone Regeneration

Engineering a proper immune response following biomaterial implantation is essential to bone tissue regeneration. Herein, a biomimetically hierarchical scaffold composed of deferoxamine@poly(ε-caprolactone) nanoparticles (DFO@PCL NPs), manganese carbonyl (MnCO) nanosheets, gelatin methacryloyl hydrogel, and a polylactide/hydroxyapatite (HA) matrix is fabricated to augment bone repair by facilitating the balance of the immune system and bone metabolism. First, a 3D printed stiff scaffold with a well-organized gradient structure mimics the cortical and cancellous bone tissues; meanwhile, an inside infusion of a soft hydrogel further endows the scaffold with characteristics of the extracellular matrix. A Fenton-like reaction between MnCO and endogenous hydrogen peroxide generated at the implant-tissue site triggers continuous release of carbon monoxide and Mn²⁺ , thus significantly lessening inflammatory response by upregulating the M2 phenotype of macrophages, which also secretes vascular endothelial growth factor to induce vascular formation. Through activating the hypoxia-inducible factor-1α pathway, Mn²⁺ and DFO@PCL NP further promote angiogenesis. Moreover, DFO inhibits osteoclast differentiation and synergistically collaborates with the osteoinductive activity of HA. Based on amounts of data in vitro and in vivo, strong immunomodulatory, intensive angiogenic, weak osteoclastogenic, and superior osteogenic abilities of such an osteoimmunity-regulating scaffold present a profound effect on improving bone regeneration, which puts forward a worthy base and positive enlightenment for large-scale bone defect repair.

Targeted intelligent mesoporous polydopamine nanosystems for multimodal synergistic tumor treatment

Developing intelligent responsive platforms to carry out high-performance therapy is of great interest for the treatment of tumors and their metastases. However, effective drug loading, activity maintenance, off-target leakage, and response to collaborative therapy remain great challenges. Herein, a targeted intelligent responsive mesoporous polydopamine (MPDA) nanosystem was reported for use in gene-mediated photochemotherapy for synergistic tumor treatment. First, the MPDA was surface modified to maintain a positive charge near the surface and to impart active targeting. Then, gambogic acid (GA) was encapsulated in the MPDA, solidified by phase change materials (PCMs), and finally loaded with siRNA by electrostatic interactions to obtain the smart nanodelivery system (PPMD@GA/si). In vitro and in vivo experiments showed that it not only effectively avoids siRNA inactivation and accidental release of GA, but also possesses potential for targeted accumulation to tumor tissue and mild-temperature photothermal therapy and chemotherapy via near infrared (NIR) radiation. Additionally, the release of siRNA could also effectively inhibit tumor invasion and metastasis to realize multimodal synergistic therapy. Overall, our studies provide a promising idea for synergistic tumor and metastasis treatment based on vector construction.

Mesoporous Polydopamine Loaded Pirfenidone Target to Fibroblast Activation Protein for Pulmonary Fibrosis Therapy

Recently, fibroblast activation protein (FAP), an overexpressed transmembrane protein of activated fibroblast in pulmonary fibrosis, has been considered as the new target for diagnosing and treating pulmonary fibrosis. In this work, mesoporous polydopamine (MPDA), which is facile prepared and easily modified, is developed as a carrier to load antifibrosis drug pirfenidone (PFD) and linking FAP inhibitor (FAPI) to realize lesion-targeted drug delivery for pulmonary fibrosis therapy. We have found that PFD@MPDA-FAPI is well biocompatible and with good properties of antifibrosis, when ICG labels MPDA-FAPI, the accumulation of the nanodrug at the fibrosis lung in vivo can be observed by NIR imaging, and the antifibrosis properties of PFD@MPDA-FAPI in vivo were also better than those of pure PFD and PFD@MPDA; therefore, the easily produced and biocompatible nanodrug PFD@MPDA-FAPI developed in this study is promising for further clinical translations in pulmonary fibrosis antifibrosis therapy.

Molecular imaging nanoprobes for theranostic applications

As a non-invasive imaging monitoring method, molecular imaging can provide the location and expression level of disease signature biomolecules in vivo, leading to early diagnosis of relevant diseases, improved treatment strategies, and accurate assessment of treating efficacy. In recent years, a variety of nanosized imaging probes have been developed and intensively investigated in fundamental/translational research and clinical practice. Meanwhile, as an interdisciplinary discipline, this field combines many subjects of chemistry, medicine, biology, radiology, and material science, etc. The successful molecular imaging not only requires advanced imaging equipment, but also the synthesis of efficient imaging probes. However, limited summary has been reported for recent advances of nanoprobes. In this paper, we summarized the recent progress of three common and main types of nanosized molecular imaging probes, including ultrasound (US) imaging nanoprobes, magnetic resonance imaging (MRI) nanoprobes, and computed tomography (CT) imaging nanoprobes. The applications of molecular imaging nanoprobes were discussed in details. Finally, we provided an outlook on the development of next generation molecular imaging nanoprobes.

An injectable and biodegradable hydrogel incorporated with photoregulated NO generators to heal MRSA-infected wounds

The development of degradable hydrogel fillers with high antibacterial activity and wound-healing property is urgently needed for the treatment of infected wounds. Herein, an injectable, degradable, photoactivated antibacterial hydrogel (MPDA-BNN6@Gel) was developed by incorporating BNN6-loaded mesoporous polydopamine nanoparticles (MPDA-BNN6 NPs) into a fibrin-based hydrogel. After administration, MPDA-BNN6@Gel created local hyperthermia and released large quantities of NO gas to treat methicillin-resistant Staphylococcus aureus infection under the stimulation of an 808 nm laser. Experiments confirmed that the bacteria were eradicated through irreversible damage to the cell membrane, genetic metabolism, and material energy. Furthermore, in the absence of laser irradition, the fibrin and small amount of NO that originated from MPDA-BNN6@Gel promoted wound healing in vivo. This work indicates that MPDA-BNN6@Gel is a promising alternative for the treatment of infected wounds and provides a facile tactic to design a photoregulated bactericidal hydrogel for accelerating infected wound healing. STATEMENT OF SIGNIFICANCE: The development of a degradable hydrogel with high antibacterial activity and wound-healing property is an urgent need for the treatment of infected wounds. Herein, an injectable, degradable, and photo-activated antibacterial hydrogel (MPDA-BNN6@Gel) has been developed by incorporating BNN6-loaded mesoporous polydopamine nanoparticles (MPDA-BNN6 NPs) into a fibrin-based hydrogel. After administration of MPDA-BNN6@Gel, the MPDA-BNN6@Gel could generate local hyperthermia and release large quantities of NO gas to treat the methicillin-resistant Staphylococcus aureus infection under the irradiation of 808 nm laser. Furthermore, in the absence of a laser, the fibrin and a small amount of NO originating from MPDA-BNN6@Gel could promote wound healing in vivo.

Polyserotonin as a versatile coating with pH-responsive degradation for anti-tumor therapy

Through self-polymerization of serotonin monomer, polyserotonin (PST) can coat on arbitrary surfaces with pH-responsive degradation, which was employed for nanoparticle coating and controlled drug release, achieving a robust anti-tumor effect when combined with its intrinsic photothermal effect.

Use of mesoporous polydopamine nanoparticles as a stable drug-release system alleviates inflammation in knee osteoarthritis

Osteoarthritis drugs are often short-acting; therefore, to enhance their efficacy, long-term, stable-release, drug-delivery systems are urgently needed. Mesoporous polydopamine (MPDA), a natural nanoparticle with excellent biocompatibility and a high loading capacity, synthesized via a self-aggregation-based method, is frequently used in tumor photothermal therapy. Here, we evaluated its efficiency as a sustained and controlled-release drug carrier and investigated its effectiveness in retarding drug clearance. To this end, we used MPDA as a controlled-release vector to design a drug-loaded microsphere system (RCGD423@MPDA) for osteoarthritis treatment, and thereafter, tested the efficacy of the system in a rat model of osteoarthritis. The results indicated that at an intermediate drug-loading dose, MPDA showed high drug retention. Furthermore, the microsphere system maintained controlled drug release for over 28 days. Our in vitro experiments also showed that drug delivery using this microsphere system inhibited apoptosis-related cartilage degeneration, whereas MPDA-only administration did not show obvious cartilage degradation improvement effect. Results from an in vivo osteoarthritis model also confirmed that drug delivery via this microsphere system inhibited cartilage damage and proteoglycan loss more effectively than the non-vectored drug treatment. These findings suggest that MPDA may be effective as a controlled-release carrier for inhibiting the overall progression of osteoarthritis. Moreover, they provide insights into the selection of drug-clearance retarding vectors, highlighting the applicability of MPDA in this regard.

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.

A targeting mesoporous dopamine nanodrug platform with NIR responsiveness for atherosclerosis improvement

Atherosclerosis (AS), the formation of plaque lesions in the walls of arteries, causes many mortalities and morbidities worldwide. Currently, achieving site-specific delivery and controlled release at plaques is difficult. Herein, we implemented the strategy of constructing a bionic multifunctional nanoplatform (BM-NP) for targeting and improving plaques. BM-NPs were prepared based on probucol-loaded mesoporous polydopamine (MPDA) carriers and were coated with platelet membranes to impart bionic properties. In vitro experiments confirmed that BM-NPs, which respond to near-infrared (NIR) for drug release, remove reactive oxygen species (ROS), thereby reducing the level of oxidized low-density lipoprotein (ox-LDL) and ultimately helping to inhibit macrophage foaming. In vivo experiments proved that BM-NPs actively accumulated in plaques in the mouse right carotid artery (RCA) ligation model. During treatment, BM-NPs with NIR laser irradiation more effectively reduced the area of plaque deposition and slowed the thickening of the arterial wall intima. More importantly, BM-NPs showed the advantage of inhibiting the increase in triglyceride (TG) content in the body, and good biocompatibility. Hence, our research results indicate that intelligent BM-NPs can be used as a potential nanotherapy to precisely and synergistically improve AS.

Mesoporous polydopamine-based multifunctional nanoparticles for enhanced cancer phototherapy

Cancer phototherapy has attracted increasing attention for its effectiveness, relatively low side effect, and noninvasiveness. The combination of photothermal therapy (PTT) and photodynamic therapy (PDT) has been shown to exhibit promising prospects in cancer treatment. However, the tumor hypoxia, high level of intracellular glutathione (GSH), and insufficient photosensitizer uptake significantly limit the PDT efficacy. In this work, we combine oxygen supply, GSH depletion, and tumor targeting in one nanoplatform, folate-decorated mesoporous polydopamine nanoparticles (FA-MPPD) co-loaded with new indocyanine green (IR-820) and perfluorooctane (PFO) (IR-820/PFO@FA-MPPD), to overcome the PDT resistance for enhanced cancer PDT/PTT. IR-820/PFO@FA-MPPD exhibit efficient singlet oxygen generation and photothermal effect under 808 nm laser irradiation, GSH-promoted IR-820 release, and efficient cellular uptake, resulting in high intracellular reactive oxygen species (ROS) level under 808 nm laser irradiation and strong photocytotoxicity in vitro. Following intratumoral injection, IR-820/PFO@FA-MPPD can relieve tumor hypoxia sustainably by PFO-mediated oxygen transport and deplete intracellular GSH by the Michael addition reaction, which boost the PDT effect and lead to the most potent antitumor effect upon 808 nm laser irradiation. The multifunctional IR-820/PFO@FA-MPPD developed in this work offer a relatively simple and effective strategy to potentiate PDT for efficient cancer phototherapy.

Surgical Tumor-Derived Photothermal Nanovaccine for Personalized Cancer Therapy and Prevention

Recent breakthroughs in cell membrane-fabricated nanovaccine offer innovateive therapeutic options for preventing tumor metastasies and recurrence, yet the treatment of patient-specific solid tumor remained challenging owing to the immunosuppressive tumor microenvironment. Herein, we developed a personalized photothermal nanovaccine based on the surgical tumor-derived cell membranes (CMs) coating resiquimod (R848) loaded mesoporous polydopamine (MPDA) nanoparticles for targeting tumor photothermal immunotherapy and prevention. The fabricated photothermal nanovaccine MPDA-R848@CM (MR@C) demonstrates outstanding imaging-guided photothermal immunotherapy efficacy to eradicate solid tumors under near-IR laser irradiation and further inhibiting metastasis tumors by the resulted antitumor immunities, especially in combination with programmed death-ligand 1 antibody therapy (aPD-L1). Furthermore, from in vivo prophylactic testing results, it is confirmed that the 4T1 cells rechallenge can be prevented 100% in postsurgical tumor model after vaccination of the photothermal nanovaccine. Our work fabricates a personalized photothermal nanovaccine that possesses great potential for tumor-specific treatment and for preventing postoperative tumor recurrence.

Multifunctional hydrogel platform for biofilm scavenging and O2 generating with photothermal effect on diabetic chronic wound healing

Diabetic wound treatment remains a major challenge due to the difficulties of eliminating bacterial biofilm and relieving wound hypoxia. To address these issues simultaneously, a multifunctional Dex-SA-AEMA/MnO₂/PDA (DSAMP) hydrogel platform was developed with excellent biocompatibility and porous structure. The hydrogel could absorb the exudate, maintain humidity and permeate oxygen, which was prepared by encapsulating polydopamine (PDA) and manganese dioxide (MnO₂) into Dex-SA-AEMA (DSA) hydrogel by UV irradiation. With the addition of PDA, the DSAMP hydrogel was proved to eliminate the biofilm after NIR photodynamic therapy (PTT, 808 nm) irradiation at 54 °C. Furthermore, in order to mitigate hypoxia wound microenvironment, MnO₂ nanoparticles were added to convert the endogenous hydrogen peroxide (H₂O₂) into oxygen (O₂, 16 mg L^-1). The diabetic wound in vivo treated by DSAMP hydrogel was completely healed on 14 days. It was revealed that the DSAMP hydrogel possessed a great potential as dressing for diabetic chronic wound healing.

An Ultrasmall Fe3 O4 -Decorated Polydopamine Hybrid Nanozyme Enables Continuous Conversion of Oxygen into Toxic Hydroxyl Radical via GSH-Depleted Cascade Redox Reactions for Intensive Wound Disinfection

Nanozyme-based chemodynamic therapy (CDT) for fighting bacterial infections faces several major obstacles including low hydrogen peroxide (H₂ O₂ ) level, over-expressed glutathione (GSH) in infected sites, and inevitable damage to healthy tissue with abundant nonlocalized nanozymes. Herein, a smart ultrasmall Fe₃ O₄ -decorated polydopamine (PDA/Fe₃ O₄ ) hybrid nanozyme is demonstrated that continuously converts oxygen into highly toxic hydroxyl radical (•OH) via GSH-depleted cascade redox reactions for CDT-mediated bacterial elimination and intensive wound disinfection. In this system, photonic hyperthermia of PDA/Fe₃ O₄ nanozymes can not only directly damage bacteria, but also improve the horseradish peroxidase-like activity of Fe₃ O₄ decorated for CDT. Surprisingly, through photothermal-enhanced cascade catalytic reactions, PDA/Fe₃ O₄ nanozymes can consume endogenous GSH for disrupting cellular redox homeostasis and simultaneously provide abundant H₂ O₂ for improving •OH generation, ultimately enhancing the antibacterial performance of CDT. Such PDA/Fe₃ O₄ can bind with bacterial cells, and reveals excellent antibacterial property against both Staphylococcus aureus and Escherichia coli. Most interestingly, PDA/Fe₃ O₄ nanozymes can be strongly retained in infected sites by an external magnet for localized long-term in vivo CDT and show minimal toxicity to healthy tissues and organs. This work presents an effective strategy to magnetically retain the therapeutic nanozymes in infected sites for highly efficient CDT with good biosafety.

Controllable synthesis of variable-sized magnetic nanocrystals self-assembled into porous nanostructures for enhanced cancer chemo-ferroptosis therapy and MR imaging

Magnetic-based nanomaterials are promising for cancer diagnosis and treatment. Herein, we develop a self-assembled approach for the preparation of a porous magnetic nanosystem, DOX/Mn(0.25)-Fe₃O₄-III NPs, which can simultaneously achieve chemotherapy, ferroptosis therapy and MRI to improve the therapeutic efficacy. By tuning its porous structures, whole particle sizes and compositions, this nanosystem possesses both a high drug loading capacity and excellent Fenton reaction activity. Owing to the synergetic catalysis effect of iron and manganese ions, the Fenton catalytic activity of Mn(0.25)-Fe₃O₄-III NPs (K _cat = 1.2209 × 10^-2 min^-1) was six times higher than that of pure porous Fe₃O₄ NPs (K _cat = 1.9476 × 10^-3 min^-1), making them greatly advantageous in ferroptosis-inducing cancer therapy. Moreover, we found out that these Mn(0.25)-Fe₃O₄-III NPs show a pH-dependent Fenton reaction activity. At acidic tumorous pH, this nanosystem could catalyze H₂O₂ to produce the cytotoxic ˙OH to kill cancer cells, while in neutral physiological conditions it decomposed H₂O₂ into biosafe species (H₂O and O₂). In vivo studies demonstrated that DOX/Mn(0.25)-Fe₃O₄-III NPs exhibited a significant synergistic anticancer effect of combining chemotherapy and ferroptosis therapy and effective T₂-weighted MRI with minimal side effects. Therefore, this porous magnetic nanoplatform has a great potential for combined diagnosis and therapy in future clinical applications.

Mesoporous Doxorubicin-Loaded Polydopamine Nanoparticles Coated with a Platelet Membrane Suppress Tumor Growth in a Murine Model of Human Breast Cancer

Bringing together photothermal therapy and chemotherapy (photothermal-chemotherapy, PT-CT) is a highly promising clinical approach but requires the development of intelligent multifunctional delivery vectors. In this work, we prepared mesoporous polydopamine nanoparticles (MPDA NPs) loaded with the chemotherapeutic drug doxorubicin (DOX). These NPs were then coated with the platelet membrane (PLTM). The coated MPDA NPs are spherical and clearly mesoporous in structure. They have a particle size of approximately 184 nm and pore size of ca. 45 nm. The NPs are potent photothermal agents and efficient DOX carriers, with increased rates of drug release observed in vitro in conditions representative of the tumor microenvironment. The NPs are preferentially taken up by cancer cells but not by macrophage cells, and while cytocompatible with healthy cells are highly toxic to cancer cells. An in vivo murine model of human breast cancer revealed that the NPs can markedly slow the growth of a tumor (ca. 9-fold smaller after 14 days' treatment), have extended pharmacokinetics compared to free DOX (with DOX still detectable in the bloodstream after 24 h when the NPs are applied), and are highly targeted with minimal off-site effects on the heart, liver, spleen, kidney, and lungs.

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.

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

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

Photoacoustic image-guided corpus cavernosum intratunical injection of adipose stem cell-derived exosomes loaded polydopamine thermosensitive hydrogel for erectile dysfunction treatment

Stem cell-derived exosomes (SC-EXO) was an emerging therapeutic agent in regenerative medicine. Intratunical injection of SC-EXO is considered as a prospective approach for erectile dysfunction (ED) treatment. However, high vascularization of cavernous body makes effective retention a major challenge for SC-EXO intratunical injection. In this study, a Polydopamine nanoparticles (PDNPs) incorporated poly (ethylene glycol)-poly(ε-caprolactone-co-lactide) (PDNPs-PELA) thermosensitive hydrogels were fabricated by a facile in situ polymerization for intratunical administration of adipose stem cell-derived exosomes (EXO). The hydrogels exhibited sol-gel transition at body temperature. Moreover, the in-situ polymerization of PDNPs using poly (ethylene glycol)-poly(ε-caprolactone-co-lactide) (PELA) block copolymer as a template was found to be more stable dispersion in the gel system. After being encapsulated into the hydrogel, EXO shows sustained release behavior within two weeks. In vivo animal experiments revealed that exosomes released from hydrogel lead to the healing of endothelial cells and neurons, increase of the cavity's pressure, thereby restoring the erectile function. In particular, since the PDNPs in thermosensitive gels have excellent photoacoustic performance, the hydrogel can be accurately delivered into the tunica albuginea by the guidance of real-time photoacoustic imaging. These results suggest that the as-prepared PDNPs-PELA has a promising future as an injectable exosome carrier for ED treatment.

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A temperature-sensitive hydrogel with photoacoustic activity was developed for intratunical injection by in-situ polymerization.

•The exosomes encapsulated in the hydrogel can be slowly released and effectively restore damaged nerve and vascular endothelial cells.

•The injection guided by photoacoustic images realizes accurate puncture and real-time filling detection of hydrogel in the corpus cavernosum.

Recent developments in mesoporous polydopamine-derived nanoplatforms for cancer theranostics

Polydopamine (PDA), which is derived from marine mussels, has excellent potential in early diagnosis of diseases and targeted drug delivery owing to its good biocompatibility, biodegradability, and photothermal conversion. However, when used as a solid nanoparticle, the application of traditional PDA is restricted because of the low drug-loading and encapsulation efficiencies of hydrophobic drugs. Nevertheless, the emergence of mesoporous materials broaden our horizon. Mesoporous polydopamine (MPDA) has the characteristics of a porous structure, simple preparation process, low cost, high specific surface area, high light-to-heat conversion efficiency, and excellent biocompatibility, and therefore has gained considerable interest. This review provides an overview of the preparation methods and the latest applications of MPDA-based nanodrug delivery systems (chemotherapy combined with radiotherapy, photothermal therapy combined with chemotherapy, photothermal therapy combined with immunotherapy, photothermal therapy combined with photodynamic/chemodynamic therapy, and cancer theranostics). This review is expected to shed light on the multi-strategy antitumor therapy applications of MPDA-based nanodrug delivery systems.

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.

Biodegradable Nanocatalyst with Self-Supplying Fenton-like Ions and H2O2 for Catalytic Cascade-Amplified Tumor Therapy

Therapeutic nanosystems triggered by a specific tumor microenvironment (TME) offer excellent safety and selectivity in the treatment of cancer by in situ conversion of a less toxic substance into effective anticarcinogens. However, the inherent antioxidant systems, hypoxic environment, and insufficient hydrogen peroxide (H₂O₂) in tumor cells severely limit their efficacy. Herein, a new strategy has been developed by loading the chemotherapy prodrug disulfiram (DSF) and coating glucose oxidase (GOD) on the surface of Cu/ZIF-8 nanospheres and finally encapsulating manganese dioxide (MnO₂) nanoshells to achieve efficient DSF-based cancer chemotherapy and dual-enhanced chemodynamic therapy (CDT). In an acidic TME, the nanocatalyst can biodegrade rapidly and accelerate the release of internal active substances. The outer layer of MnO₂ depletes glutathione (GSH) to destroy the reactive oxygen defensive mechanisms and achieves continuous oxygen generation, thus enhancing the catalytic efficiency of GOD to burst H₂O₂. Benefiting from the chelation reaction between the released Cu²⁺ and DSF, a large amount of cytotoxic CuET products is generated, and the Cu⁺ are concurrently released, thereby achieving efficient chemotherapy and satisfactory CDT efficacy. Furthermore, the release of Mn²⁺ can initiate magnetic resonance imaging signals for the tracking of the nanocatalyst.

Redox-mediated carbon monoxide release from a manganese carbonyl-implications for physiological CO delivery by CO releasing moieties

The dynamics of hydrogen peroxide reactions with metal carbonyls have received little attention. Given reports that therapeutic levels of carbon monoxide are released in hypoxic tumour cells upon manganese carbonyls reactions with endogenous H2O2, it is critical to assess the underlying CO release mechanism(s). In this context, a quantitative mechanistic investigation of the H2O2 oxidation of the water-soluble model complex fac-[Mn(CO)3(Br)(bpCO2)]2-, (A, bpCO2 2- = 2,2'-bipyridine-4,4'-dicarboxylate dianion) was undertaken under physiologically relevant conditions. Characterizing such pathways is essential to evaluating the viability of redox-mediated CO release as an anti-cancer strategy. The present experimental studies demonstrate that approximately 2.5 equivalents of CO are released upon H2O2 oxidation of A via pH-dependent kinetics that are first-order both in [A] and in [H2O2]. Density functional calculations were used to evaluate the key intermediates in the proposed reaction mechanisms. These pathways are discussed in terms of their relevance to physiological CO delivery by carbon monoxide releasing moieties.

A Novel H2O2 Generator for Tumor Chemotherapy-Enhanced CO Gas Therapy

Carbon monoxide (CO) gas therapy is a promising cancer treatment. However, gas delivery to the tumor site remains problematic. Proper tunable control of CO release in tumors is crucial to increasing the efficiency of CO treatment and reducing the risk of CO poisoning. To overcome such challenges, we designed ZCM, a novel stable nanotechnology delivery system comprising manganese carbonyl (MnCO) combined with anticancer drug camptothecin (CPT) loaded onto a zeolitic imidazole framework-8 (ZIF-8). After intravenous injection, ZCM gradually accumulates in cancerous tissues, decomposing in the acidic tumor microenvironment, releasing CPT and MnCO. CPT acts as a chemotherapy agent destroying tumors and producing copious H2O2. MnCO can react with the H2O2 to generate CO, powerfully damaging the tumor. Both in vitro and in vivo experiments indicate that the ZCM system is both safe and has excellent tumor inhibition properties. ZCM is a novel system for CO controlled release, with significant potential to improve future cancer therapy.

Tailoring morphologies of mesoporous polydopamine nanoparticles to deliver high-loading radioiodine for anaplastic thyroid carcinoma imaging and therapy

Anaplastic thyroid carcinoma (ATC), as one of the most aggressive human malignancies, cannot be cured by ¹³¹iodine (¹³¹I) internal radiotherapy (RT) because the tumor cells cannot effectively take up ¹³¹I and are resistant to radiotherapy. In this study, a facile and simple method was proposed to synthesize mesoporous polydopamine nanoparticles (MPDA) and tailor their morphologies by component-adjusting Pluronic micelle-guided polymerization. Then, MPDA were used not only as nanocarriers to radiolabel ¹³¹I, but also as photothermal conversion agents for photothermal therapy (PTT) to promote RT. The iodine-labeling capacity and photothermal conversion efficiency of MPDA can be enhanced by optimizing their morphologies. It was found that MPDA NPs with a cerebroid pore channel structure (CPDA) showed the highest iodine-carrying capacity and a higher photothermal conversion efficiency as a result of their maximum specific surface area and unique morphology. In subsequent experiments in vitro and in vivo, our ATC animal models showed impressive therapeutic responses to CPDA-¹³¹I NPs because of the synergistic effect of PTT and RT. Additionally, CPDA-¹²⁵I NPs can be utilized to obtain high-quality SPETC/CT images of tumors, which can guide clinical therapy for ATC. Considering their great biosafety, these radioiodine-labeled CPDA NPs may serve as a promising tool in combined therapy and diagnosis in ATC.

Carambola-like Bi2Te3 superstructures with enhanced photoabsorption for highly efficient photothermal therapy in the second near-infrared biowindow

Photothermal therapy (PTT) stimulated by light in the second near-infrared (NIR-II) biowindow shows great superiorities in the penetration ability of tissue and maximum permissible exposure (MPE). Exploring new photothermal agents with good optical absorbance in the NIR-II region is highly desirable for efficient cancer therapy. Herein, we successfully prepare carambola-like bismuth telluride (Bi₂Te₃) superstructures modified with PEGylated phospholipid (Bi₂Te₃@PEG) for CT imaging-guided PTT in the NIR-II biowindow. Attributing to their superstructures, Bi₂Te₃@PEG exhibited enhanced photoabsorption with higher photothermal conversion efficiency (55.3% for 1064 nm) compared with that of Bi₂Te₃ nanoparticles. Furthermore, the good X-ray attenuation capacity of Bi endows Bi₂Te₃@PEG with an outstanding performance as computed tomography (CT) contrast agents. Bi₂Te₃@PEG superstructures have been confirmed to effectively eliminate tumor in vitro and in vivo with negligible long-term toxicities, offering them great potential to act as theranostic platforms for cancer diagnosis and treatment.

Multifunctional carbon monoxide nanogenerator as immunogenic cell death drugs with enhanced antitumor immunity and antimetastatic effect

The limited effect of immune checkpoint blockade (ICB) immunotherapy is subjected to the immuno-suppressive tumor microenvironment (TME). It is still a challenge to reverse the immune-suppressive state in clinical cancer therapy. Immunogenic cell death (ICD) is a way for inducing the therapeutical tumor immune system. In this work, carbon monoxide (CO) gas therapy is used to boost antitumor immunity for tumor control, metastasis and recurrence prevention. Briefly, CO₂-g-C₃N₄-Au@ZIF-8@F127 (CCAZF) is proposed to integrate gas therapy and immunotherapy into a photocatalytic nanogenerator for overcoming the limitations of monotherapy. CCAZF exhibits a highly effective light-controllable release behavior of CO, which gradually aggravates the oxidative stress in tumor cells to induce ICD. With the induction of ICD, CO therapy enhances immune responses and enables efficient immune cells activated. When combined with ICB, CCAZF displays an enhanced immune effect, which mediates the regression of primary and distal tumors. This strategy of in-situ photocatalytic CO therapy furthest avoids the toxicity from CO leakage and provides a new method to design novel ICD inducers.

Self-Assembled Fluorosome-Polydopamine Complex for Efficient Tumor Targeting and Commingled Photodynamic/Photothermal Therapy of Triple-Negative Breast Cancer

Photodynamic/photothermal therapy (PDT/PTT) that deploys a near-infrared responsive nanosystem is emerging to be a promising modality in cancer treatment. It is highly desirable to have a multifunctional nanosystem that can be used for efficient tumor targeting and inhibiting metastasis/recurrence of cancer. In the current study, self-assembled chlorophyll-rich fluorosomes derived from Spinacia oleracea were developed. These fluorosomes were co-assembled on a polydopamine core, forming camouflaged nanoparticles (SPoD NPs). The SPoD NPs exhibited a commingled PDT/PTT (i.e., interdependent PTT and PDT) that inhibited both normoxic and hypoxic cancer cell growth. These nanoparticles showed stealth properties with enhanced physiological stability and passive tumor targeting. SPoD NPs also exhibited tumor suppression by synergistic PTT and PDT. It also prevented lung metastasis and splenomegaly in tumor-bearing Balb/c mice. Interestingly, treatment with SPoD NPs also caused the suppression of secondary tumors by eliciting an anti-tumor immune response. In conclusion, a co-assembled multifunctional nanosystem derived from S. oleracea showed enhanced stability and tumor-targeting efficacy, resulting in a commingled PDT/PTT effect.

Therapeutic gas delivery strategies

Gas molecules with pharmaceutical effects offer emerging solutions to diseases. In addition to traditional medical gases including O₂ and NO, more gases such as H₂ , H₂ S, SO₂ , and CO have recently been discovered to play important roles in various diseases. Though some issues need to be addressed before clinical application, the increasing attention to gas therapy clearly indicates the potentials of these gases for disease treatment. The most important and difficult part of developing gas therapy systems is to transport gas molecules of high diffusibility and penetrability to interesting targets. Given the particular importance of gas molecule delivery for gas therapy, distinguished strategies have been explored to improve gas delivery efficiency and controllable gas release. Here, we summarize the strategies of therapeutic gas delivery for gas therapy, including direct gas molecule delivery by chemical and physical absorption, inorganic/organic/hybrid gas prodrugs, and natural/artificial/hybrid catalyst delivery for gas generation. The advantages and shortcomings of these gas delivery strategies are analyzed. On this basis, intelligent gas delivery strategies and catalysts use in future gas therapy are discussed. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Vitamin E-facilitated carbon monoxide pro-drug nanomedicine for efficient light-responsive combination cancer therapy

The quest to maximize therapeutic efficiency in cancer treatment requires innovative delivery nanoplatforms capable of employing different modules simultaneously. Combination therapy has proven to be one of the best anticancer strategies so far. Herein, we have developed a lipid-encapsulated nanoplatform that combines chemotherapy with photoresponsive gas therapy for colon cancer treatment. Carbon monoxide releasing molecules (CORMs) and vitamin E analogues (pure/pegylated α-tocopheryl succinate; α-TOS) were co-loaded into the lipid layer with core-shell upconversion nanoparticles (UCNPs), which converted 808 nm light to 360 nm photons to trigger CO release at the tumor site. This folic acid (FA)-targeting nanomedicine (Lipid/UCNP/CORM/α-TOS/FA: LUCTF) possessed a cancer-targeting ability and a light-triggered CO release ability for synergistic apoptosis of HCT116 cells via enhanced ROS generation and mitochondrial membrane breaking. In vivo data have confirmed the significantly enhanced therapeutic efficacy of LUCTF without any significant biosafety issues after intravenous administration. Thus, nanomedicine LUCTF represents a novel way for efficient cancer therapy via combining locally released CO and a compatible chemotherapeutic agent (e.g. α-TOS).

A versatile nanoagent for multimodal imaging-guided photothermal and anti-inflammatory combination cancer therapy

Photothermal therapy (PTT) has drawn great attention in cancer treatment because of its minimal invasiveness and high spatiotemporal selectivity, but it still encounters severe obstacles like heat-resistance, metastasis and recurrence. A key reason for the treatment failure is the highly inflammatory tumor microenvironment caused by hyperthermia. A simultaneous anti-inflammatory therapy alongside the PTT has great potential for overcoming the drawbacks of PTT; however, it has been less reported and further study is urgently needed. In addition, as many inorganic photothermal agents have no inherent imaging capability, diagnostic strategies should be introduced to help identify cancerous lesions and find the best treatment time period for PTT. Herein, we developed a versatile theranostic nanoagent (named T-lipos-CPAuNCs) for synergistic multimodal imaging-guided photothermal/anti-inflammatory cancer therapy. Perfluorohexane (PFH) loaded AuNCs and the anti-inflammatory drug celecoxib were encapsulated into the tumor-targeting cyclic Arg-Gly-Asp (cRGD) peptide modified liposomes to form T-lipos-CPAuNCs. The T-lipos-CPAuNCs accumulated in the tumor tissue and selectively targeted the cancer cells, and converted photo to thermal energy under near-infrared (NIR) laser irradiation to kill the cancer cells by PTT. The high temperature further accelerated the release of celecoxib to exert an anti-inflammatory effect, while on the other hand led to liquid to gas phase transition of PFH to facilitate ultrasound (US) imaging. The T-lipos-CPAuNCs also exhibited photoacoustic (PA) imaging capability. In vitro and in vivo experiments established that under the guidance of multimodal imaging, T-lipos-CPAuNCs significantly suppressed the tumor growth by PTT and prevented tumor metastasis with non-apparent tumor inflammation. The developed theranostic nanosystem (T-lipos-CPAuNCs) shows great potential for PA/US multimodal imaging guided photothermal/anti-inflammatory combination cancer therapy.