Mesoporous Polydopamine Research Articles

Droplet‐Directed Anisotropic Assembly of Semifootball‐Like Carbon Nanoparticles with Multimodal Pore Architectures

AbstractHierarchical porous carbon nanoparticles, with tailored asymmetric morphologies and pore structures, have great implications in high‐performance electrode materials. However, the controlled synthesis of anisotropic carbon nanoparticles with tailored multimodal pore structures remains a challenge. Herein, a droplet‐directed anisotropic assembly approach to synthesize asymmetric carbon nanoparticles with macro/mesopores is demonstrated. This synthesis relies on the anisotropic growth of mesoporous polydopamine (PDA) seeds on the emulsion interfaces and the subsequent immersion of 1,3,5‐trimethylbenzene (TMB) droplets into the seeds. The obtained carbon nanoparticles present a semifootball‐shaped morphology with a high surface area (383 m2 g−1), well‐controlled macropores (≈105 nm), and mesopores (≈3.8 nm). By tuning the polarity of the oil phase, the morphologies transform from non‐porous spheres to semifootball‐like architectures and finally to nano‐ellipsoid with meso‐channels. The pore structures are further optimized by ZnCl2 activation, and the semifootball‐like carbon nanoparticles with modulated pore compositions deliver a high reversible capability, excellent rate performance (215 F g−1 at 0.05 A g−1 and 143 F g−1 at 20 A g−1 in organic electrolyte), and enhanced energy density (53.4 Wh Kg−1). Simulation results elucidate the structure–activity relationship between the multistage pore structure and electrochemical performance, i.e., pore hierarchy enhances ion diffusion flux, and large‐mesopore structure facilitates rate performance.

Mesoporous polydopamine Targeting CDK4/6 Inhibitor toward Brilliant Synergistic Immunotherapy of Breast Cancer.

Immunotherapy utilizing anti-PD-L1 blockade has achieved dramatic success in clinical breast cancer management but is often hampered by the limited immune response. Increasing evidence shows that immunogenic cell death (ICD) recently arises as a promising strategy for enlarging tumor immunogenicity and eliciting systemic anti-tumor immunity effectively. However, developing simple but versatile, highly efficient but low-toxic, biosafe, and clinically available transformed ICD inducers remains a huge demand and is highly desirable. Herein, a multifunctional ICD inducer is purposefully developed A6-MPDA@PAL by integrating photothermal therapy (PTT) nanoplatforms mesoporous polydopamine (MPDA), CDK4/6 inhibitor palbociclib (PAL), and CD44-specific targeting A6 peptide in a simple way for augmenting the immune antitumor efficacy of anti-PD-L1 therapy. Remarkably, the light-inducible nanoplatforms exhibit multiple favorable therapeutic features ensuring a superior and biosafe PTT/chemotherapy efficacy. Together with stronger accumulative ICD induction, single administration of A6-MPDA@PAL can trigger robust systemic antitumor immunity and abscopal effect with the assistance of anti-PD-L1 blockade by fascinating the intratumoral infiltration of T lymphocytes and reversing the immunosuppressive tumor microenvironment simultaneously, therapy achieving brilliant synergistic immunotherapy with effective tumor ablation. This study presents a simple and smart ICD inducer opening up attractive clinical possibilities for reinforcing the anti-PD-L1 therapy against breast cancer.

Synergistic quorum sensing inhibition and mild-temperature photothermal therapy of integrated nanoplatform for implant-associated biofilm infections

In current clinical practice, the presence of biofilms poses a significant challenge in the effective elimination of bacterial infections because of the physical and chemical barriers formed by biofilms, which offer persistent protection to bacteria. Here, we developed hollow mesoporous polydopamine (hMP) nanoparticles (NPs) loaded with luteolin (Lu) as a quorum sensing inhibitor, which were further coated with hyaluronic acid (HA) shells to create hMP-Lu@HA NPs. We observed that upon reaching the infection site, the HA shells underwent initial degradation by the hyaluronidase enzyme present in the bacterial infection's microenvironment to expose the hMP-Lu NPs. Subsequently, Lu was released in response to the acidic conditions characteristic of bacterial infections, which effectively hindered and dispersed the biofilm. Moreover, when subjected to near-infrared irradiation, the robust photothermal conversion effect of hMP NPs accelerated the release of Lu and disrupted the integrity of the biofilms by localized heating. This dual action enhanced the eradication of the biofilm infection. Importantly, hMP-Lu@HA NPs also promoted tissue regeneration and healing at the implantation site, concurrently addressing biofilm infection. Taken together, this nanosystem, combined with mild-temperature photothermal therapy and quorum sensing inhibition strategy, holds significant potential for applications in the treatment of implantation-associated infections.

Investigating the Effectiveness of Different Porous Nanoparticles as Drug Carriers for Retaining the Photostability of Pinosylvin Derivative.

Pinosylvin monomethyl ether (PsMME) is a natural compound known for its valuable bioactive properties, including antioxidant and anti-inflammatory effects. However, PsMME's susceptibility to photodegradation upon exposure to ultraviolet (UV) radiation poses a significant limitation to its applications in the pharmaceutical field. This study, for the first time, introduces a strategy to enhance the photostability of PsMME by employing various nanoformulations. We utilized mesoporous silica nanoparticles (MSNs) coated with polydopamine via a poly(ethylene imine) layer (PDA-PEI-MSNs), thermally carbonized porous silicon nanoparticles (TCPSi), and pure mesoporous polydopamine nanoparticles (MPDA). All these nanocarriers exhibit unique characteristics, including the potential for shielding the drug from UV light, which makes them promising for enhancing the photostability of loaded drugs. Here, these three nanoparticles were synthesized and their morphological and physicochemical properties, including size and ζ-potential, were characterized. They were subsequently loaded with PsMME, and the release profiles and kinetics of all three nanoformulations were determined. To assess their photoprotection ability, we employed gas chromatography with a flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) to assess the recovery percentage of loaded PsMME before and after UV exposure for each nanoformulation. Our findings reveal that MPDA exhibits the highest protection ability, with a remarkable 90% protection against UV light on average. This positions MPDA as an ideal carrier for PsMME, and by extension, potentially for other photolabile drugs as well. As a final confirmation of its suitability as a drug nanocarrier, we conducted cytotoxicity evaluations of PsMME-loaded MPDA, demonstrating dose-dependent drug toxicity for this formulation.

Acid‐Unlocked Switch Controlled the Enzyme and CO In Situ Release to Induce Mitochondrial Damage via Synergy

AbstractCO gas therapy has attracted enormous attention in tumor therapy due to the abilities of mitochondrial damage and inhibition of cellular respiration. However, the inefficient and random release of CO greatly limit its application. Taking this into account, the study constructs an acid‐unlocked nanostructure based on MPDA‐MnCO‐GOx@DSNPs, designated as MMGD. The nanostructure enables tumor microenvironment (TME) specific enzyme and CO prodrug (manganese carbonyl, MnCO) cascade reaction, thus facilitating CO release in situ. Mesoporous polydopamine (MPDA) can provide the space for MnCO and glucose oxidase (GOx) loading. Especially, lanthanide (Ln3+)‐doped down‐shifting luminescent nanoparticles (DSNPs) can not only serve as the near‐infrared II (NIR‐II) fluorescence imaging probe, but also act as the acid‐unlocked gating switch. The slightly acidic TME can render the dissociation of DSNPs, thus exposing GOx and releasing MnCO. The catalytic reaction of GOx can produce H2O2 and create a more acidic environment, which facilitates the CO generation in situ, leading to mitochondrial damage by reducing cytochrome c oxidase activity and adenosine triphosphate (ATP) levels. Meanwhile, MPDA has the NIR light absorption capability for photothermal therapy (PTT). This study provides an ingenious strategy for efficient and controllable CO gas, starvation, and PTT of tumor guided by NIR‐II fluorescence imaging.

Synergistic Chemo-Photothermal Therapy of Breast Cancer Based on Mesoporous Polydopamine Nanoparticles Decorated with Atovaquone

Synergistic Chemo-Photothermal Therapy of Breast Cancer Based on Mesoporous Polydopamine Nanoparticles Decorated with Atovaquone

Multidimensional response of dopamine nano-system for on-demand fungicides delivery: Reduced toxicity and synergistic antibacterial effects

Considering the microenvironment of pathogens, the use of highly biocompatible antibacterial materials loaded with fungicides and the on-demand delivery of fungicides through controlled release can effectively improve the biocompatibility and antibacterial effect of existing fungicides. In this study, we used mesoporous poly-dopamine nanoparticles (MPDA NPs) as a carrier, prochloraz (Pro) as a loading agent, and benzimidazole (BIZ) and β-cyclodextrin (β-CD) complex as a blocking agent to prepare the on-demand delivery nano-pesticides Pro@MPDA-BIZ@β-CD (hereinafter abbreviated as PMBD), which can be administered at different stages. Sclerotinia sclerotiorum secretes oxalic acid factor to create an acidic microenvironment, and the nano-system quickly releases fungicide Pro into the mycelium. MPDA materials also responds to oxalic acid to jointly reduce the pathogenicity of Sclerotinia sclerotiorum, effectively inhibiting the growth of Sclerotinia sclerotiorum, and realizing the treatment of Sclerotinia sclerotiorum infection. On the other hand, when plants are not infected with Sclerotinia sclerotiorum, MPDA with a photothermal effect triggers the release of fungicides under the irradiation of near-infrared light, thus preventing Sclerotinia sclerotiorum infection. The in vitro release experiment showed that the cumulative release of Pro under low pH and near-infrared light irradiation was 2.68 times and 2.04 times higher than that under neutral and no light conditions, respectively. On the other hand, the rich functional groups on MPDA-BIZ@β-CD(hereinafter abbreviated as MBD) gave the system good wettability, and the contact angles of MBD on Chinese cabbage and tomato leaves were reduced by 14.85° and 41.54°, respectively, which enhanced its resistance to rainwater erosion and prevented the fungicides from being lost to the environment. In addition, bio-safety experiments have shown that PMBD has good biocompatibility to plant germination and soil microorganisms.

Activation of the PPARγ/NF-κB pathway by A-MPDA@Fe3O4@PVP via scavenging reactive oxygen species to alleviate hepatic ischemia-reperfusion injury.

Hepatic ischemia-reperfusion injury (IRI) is a common pathological process during hepatectomy and liver transplantation and the two primary reasons for hepatic IRI are reactive oxygen species (ROS)-mediated oxidative stress and excessive inflammatory responses. Herein, a novel antioxidant nanodrug (A-MPDA@Fe3O4@PVP) is prepared by employing L-arginine-doped mesoporous polydopamine (A-MPDA) nanoparticles as the carrier for deposition of ultra-small ferric oxide (Fe3O4) nanoparticles and further surface modification with polyvinylpyrrolidone (PVP). A-MPDA@Fe3O4@PVP not only effectively reduces the aggregation of ultra-small Fe3O4, but also simultaneously replicates the catalytic activity of catalase (CAT) and superoxide dismutase (SOD). A-MPDA@Fe3O4@PVP with good antioxidant activity can rapidly remove various toxic reactive oxygen species (ROS) and effectively regulate macrophage polarization in vitro. In the treatment of hepatic IRI, A-MPDA@Fe3O4@PVP effectively alleviates ROS-induced oxidative stress, reduces the expression of inflammatory factors, and prevents apoptosis of hepatocytes through immune regulation. A-MPDA@Fe3O4@PVP can further protect liver tissue by activating the PPARγ/NF-κB pathway. This multiplex antioxidant enzyme therapy can provide new references for the treatment of IRI in organ transplantation and other ROS-related injuries such as fibrosis, cirrhosis, and bacterial and hepatic viral infection.

Ternary low-temperature phototherapy nano-systems for the treatment of diabetic wounds.

The physicochemical environment at the sites of chronic diabetic wounds is an ideal habitat for bacteria, which exacerbate the deterioration of the microenvironment at the wound sites and consequently delay wound healing. In recent years, photothermal therapy has been considered an ideal non-antibiotic antimicrobial strategy. However, photothermal therapy alone is prone to cause damage to the body tissues. Herein, a (zeolitic imidazolate framework-8) ZIF-8/(mesoporous polydopamine) MPDA@(deoxyribonuclease I) DNase I ternary nanocomposite system was constructed, which exhibited good antimicrobial and antioxidant properties. Specifically, DNase I was first encapsulated into MPDA nanoparticles (NPs) and then coated with ZIF-8, which rapidly degrades in an acidic bacterial environment, triggering the release of antimicrobial Zn2+ and DNase I, thus enabling low-temperature (∼45 °C) PTT antimicrobial therapy. Meanwhile, the NPs can effectively regulate the oxidative stress environment at the trauma site because of the antioxidant effect of MPDA. Moreover, the experimental results of the diabetic wound infection mouse model showed that the prepared NPs could kill bacteria well and accelerate wound healing. Overall, the phototherapy strategy proposed in this study shows great potential in the treatment of chronically infected wounds.

Metal-polyphenol network coated photothermal nanocarriers for pH-activated drug delivery

The combination of photothermal and chemotherapy is a promising strategy for the synergistic inhibition of tumor cells. By exploiting the tumor microenvironment, chemotherapeutic drugs can target the tumor site, thereby enhancing their efficacy. This study focused on the development of nanodrugs, aiming to harness the synergistic photothermal and chemotherapy capabilities for enhanced anti-tumor effects. The core material was made of copper sulfide (CuS), which possesses photothermal conversion properties, while doxorubicin (DOX) was loaded on mesoporous polydopamine (MPDA). The drug-loaded nanoparticles were then encapsulated in acid-sensitive tannic acid and an Fe complex (TA-Fe). The photothermal conversion properties, drug loading, and release of DOX from CuS-MPDA-DOX@TA-Fe were then investigated. The results showed that DOX had an encapsulation ratio of 82.2 % and a release ratio of 43.49 % in an acidic environment (pH 5.2). In vitro studies showed that CuS-MPDA-DOX@TA-Fe triggered by NIR effectively inhibited tumor cell proliferation and that the tumor cells showed suitable levels of nanoparticle uptake. The results thus show that CuS-MPDA-DOX@TA-Fe nanodrugs could be utilized as a promising therapeutic strategy for cancer treatment with synergistic photothermal/chemotherapeutic anti-tumor effects.

Combined Photothermal Chemotherapy for Effective Treatment Against Breast Cancer in Mice Model.

Breast cancer ranks among the most prevalent cancers in women, characterized by significant morbidity, disability, and mortality. Presently, chemotherapy is the principal clinical approach for treating breast cancer; however, it is constrained by limited targeting capability and an inadequate therapeutic index. Photothermal therapy, as a non-invasive approach, offers the potential to be combined with chemotherapy to improve tumor cellular uptake and tissue penetration. In this research, a mesoporous polydopamine-coated gold nanorod nanoplatform, encapsulating doxorubicin (Au@mPDA@DOX), was developed. This nanoplatform was constructed by surface coating mesoporous polydopamine (mPDA) onto gold nanorods, and doxorubicin (DOX) was encapsulated in Au@mPDA owing to π-π stacking between mPDA and DOX. The dynamic diameter, zeta potential, absorbance, photothermal conversion ability, and drug release behavior were determined. The cellular uptake, cytotoxicity, deep penetration, and anti-tumor effects were subsequently investigated in 4T1 cells. After that, fluorescence imaging, photothermal imaging and pharmacodynamics studies were utilized to evaluate the anti-tumor effects in tumor-bearing mice model. This nanoplatform exhibited high drug loading capacity, excellent photothermal conversion and, importantly, pH/photothermal dual-responsive drug release behavior. The in vitro results revealed enhanced photothermal-facilitated cellular uptake, drug release and tumor penetration of Au@mPDA@DOX under near-infrared irradiation. In vivo studies confirmed that, compared with monotherapy with either chemotherapy or photothermal therapy, the anti-tumor effects of Au@mPDA@DOX are synergistically improved. Together with good biosafety and biocompatibility, the Au@mPDA@DOX nanoplatform provides an alternative method for safe and synergistic treatment of breast cancer.

Photothermal synergistic nitric oxide controlled release injectable self-healing adhesive hydrogel for biofilm eradication and wound healing.

The development of injectable self-healing adhesive hydrogel dressings with excellent bactericidal activity and wound healing ability is urgently in demand for combating biofilm infections. Herein, a multifunctional hydrogel (QP/QT-MB) with near-infrared (NIR) light-activated mild photothermal/gaseous antimicrobial activity was developed based on the dynamic reversible borate bonds and hydrogen bonds crosslinking between quaternization chitosan (QCS) derivatives alternatively containing phenylboronic acid and catechol-like moieties in conjunction with the in situ encapsulation of BNN6-loaded mesoporous polydopamine (MPDA@BNN6 NPs). Given the dynamic reversible cross-linking feature, the versatile hybrid hydrogel exhibited injectability, flexibility, and rapid self-healing ability. The numerous phenylboronic acid and catechol-like moieties on the QCS backbone confer the hydrogel with specific bacterial affinity, desirable tissue adhesion, and antioxidant stress ability that enhance bactericidal activity and facilitate the regeneration of infection wounds. Under NIR irradiation, the QP/QT-MB hydrogels exhibited a desirable mild photothermal effect and NIR-activity controllable NO delivery, combined with the endogenous contact antimicrobial activity of hydrogel, contributing jointly to induce dispersal of biofilms and disruption of the bacterial plasma membranes, ultimately leading to bacteria inactivation and biofilm elimination. In vivo experiments demonstrated that the fabricated QP/QT-MB hydrogel platform was capable of inducing efficient eradication of the S. aureus biofilm in a severely infected wound model and accelerating infected wound repair by promoting collagen deposition, angiogenesis, and suppressing inflammatory responses. Additionally, the QP/QT-MB hydrogel demonstrated excellent biocompatibility in vitro and in vivo. Collectively, the hydrogel (QP/QT-MB) reveals great potential application prospects as a promising alternative in the field of biofilm-associated infection treatment.

Study on the application of hollow mesoporous polydopamine as a nanoparticle drug carrier in tumor combination therapy

The HMPDA@Ce6/DOX@AMC nanodrug carrier realized the four-mode combination therapy of chemotherapy, photodynamic therapy, immunotherapy and gene therapy, solved the problem of targeting and had a strong inhibitory effect on tumor cells.

Nanozyme-mediated biocatalysis as a mitochondrial oxidative stress amplifier for tumor nanocatalytic immunotherapy

Nanozyme-mediated tumor catalytic therapy has recently garnered attention as a means of destroying tumor cells and eliciting anti-tumor immune responses. Herein, a copper-doped mesoporous polydopamine (CP) nanozyme modified with triphenylphosphine (TPP) and hyaluronic acid (HA) was designed as a mitochondrial oxidative stress amplifier (CPTH) for inducing apoptosis and promoting immune responses with the assistance of mild photothermal therapy. The density functional theory (DFT) revealed the superoxide dismutase-like reaction mechanism of nanozymes, and combined with 3-amino-1,2,4-triazole (AT, catalase inhibitor) to achieve the goal of increasing the source and reducing the off-target consumption of intra-mitochondrial H2O2. Meanwhile, CPTH-AT nanozyme was found to amplify mitochondrial oxidative stress by inducing powerful oxidative OH through intra-mitochondrial GSH consumption and exerting peroxidase-like activity. The induction of mitochondrial oxidative damage serves as a trigger for the release of tumor-associated antigens. Thus, CPTH-AT nanozyme combined with mild photothermal therapy caused substantial exposure of damage-associated molecular patterns, maximizing the incidence of tumor immunogenic cell death. Moreover, nanozymes further promoted the dendritic cells maturation and recruitment, increased the infiltration of cytotoxic T lymphocytes and helper T cells, and decreased the proportion of regulatory T cells. In brief, the mitochondria-targeted nanozyme-based biocatalytic immunotherapy combined with mild photothermal therapy represents a promising cancer therapeutic strategy, establishing new paradigms for improving the bio-applications of nanozymes.

Enhancing Electrocatalytic Performance via Thickness-Tuned Hollow N-Doped Mesoporous Carbon with Embedded Co Nanoparticles for Oxygen Reduction Reaction.

Improving catalytic performance relies heavily on the rational design of the spatial structure of electrocatalysts, achieved through exposure of active sites, acceleration of the charge/mass transfer rate, and confinement of the reactants. In this study, we have fabricated Co nanoparticles embedded in overhang eave-like hollow N-doped mesoporous carbon (Co@EMPC) by adjusting the thickness of mesoporous polydopamine (mPDA). Thanks to the abundance of short mesoporous channels within the porous structure and the tuned electronic properties resulting from heterojunction structures between metal and carbon, the prepared Co@EMPC provides increased accessibility to active sites and enhanced mass and charge transfer rates. These features contribute to superior performance in the oxygen reduction reaction (ORR), with a half-wave potential of 0.874 V vs RHE, as well as exceptional durability in alkaline media. This study introduces a useful approach to enhance the ORR using eave-like hollow nanoreactors.

PH-Responsive Sorafenib/Iron-Co-Loaded Mesoporous Polydopamine Nanoparticles for Synergistic Ferroptosis and Photothermal Therapy.

Ferroptosis has attracted significant attention as a new mechanism of cell death. Sorafenib (SRF) is widely considered a prototypical ferroptosis-inducing drug, particularly for liver cancer treatment. However, the low solubility and hydrophobic nature of SRF, along with the absence of synergistic therapeutic strategies, still limit its application in cancer treatment. Herein, we report a dual therapeutic method incorporating photothermal therapy and ferroptosis by using Fe-doped mesoporous polydopamine nanoparticles (Fe-mPDA@SRF-TPP) as a carrier for loading SRF and targeting triphenylphosphine (TPP). SRF molecules are efficiently encapsulated within the polydopamine nanospheres with a high loading ratio (80%) attributed to the porosity of Fe-mPDA, and the inherent biocompatibility and hydrophilicity of Fe-mPDA@SRF-TPP facilitate the transport of SRF to the target cancer cells. Under the external stimuli of acidic environment (pH 5.0), glutathione (GSH), and laser irradiation, Fe-mPDA@SRF-TPP shows sustained release of SRF and Fe ions with the ratio of 72 and 50% within 48 h. Fe-mPDA@SRF-TPP nanoparticles induce intracellular GSH depletion, inhibit glutathione peroxidase 4 (GPX4) activity, and generate hydroxyl radicals, all of which are essential components of the therapeutic ferroptosis process for killing MDA-MB-231 cancer cells. Additionally, the excellent near-infrared (NIR) light absorption of Fe-mPDA@SRF-TPP nanoparticles demonstrates their capability for photothermal therapy and further enhances the therapeutic efficiency. Therefore, this nanosystem provides a multifunctional therapeutic platform that overcomes the therapeutic limitations associated with standalone ferroptosis and enhances the therapeutic efficacy of SRF for breast cancer.

Design of chlorella-inspired and smart-responsive bio-microspheres and their application in eco-friendly anti-biofouling coatings

Anti-biofouling coating materials have attracted much attention for their diverse functionality and extensive applications in various fields, such as marine facilities, biomedical apparatus, and so on. However, it is still a huge challenge for long-term anti-fouling coatings to improve the durability, safety, sustainability, eco-friendliness, and biodiversity. Herein, a novel biomimetic coating (Bio-OHMP coating) with eco-friendly and anti-biofouling performance was constructed on the basis of chlorella-inspired amino silicone oil (ASO)-core/polydopamine-shell bio-microspheres (Bio-OHMP microspheres). The Bio-OHMP microspheres were successfully fabricated through combining the hard/soft templates with high-stored hydrophobic substance. Similar to chlorella, great substance storage and delivery function were achieved for the Bio-OHMP microspheres, attributing to the larger central cavity structure of hollow mesoporous polydopamine microspheres (HMP microspheres) and the easy acquisition of NIR/Acid/Base smart-responsive self-healing properties of the Bio-OHMP microspheres. Superhydrophobic properties of the Bio-OHMP coating were originated from the hydrophobic and rough micro/nano-structured Bio-OHMP microspheres and nanoparticles. NIR/Acid/Base smart-responsive characteristics and long-termed superhydrophobic self-healing properties of the Bio-OHMP coating were gained due to the multiple-responsive Bio-OHMP microspheres, and the coating was endowed with high-efficient and large-scale healing abilities. Besides, great anti-biofouling abilities to typical biological or organic contaminants and long-period superhydrophobicity under harsh environments of the Bio-OHMP coating were all confirmed. This novel and multifunctional Bio-OHMP coating shows great prospects in anti-fouling, anti-adhesion, or other fields, while the chlorella-inspired Bio-OHMP microspheres have great potentials to be applied to other functionalized materials.

Evaluation of Reactive Oxygen Species Scavenging of Polydopamine with Different Nanostructures.

Reactive oxygen species (ROS) play an important role in cellular metabolism and many oxidative stress-related diseases, while excessive accumulation of ROS will lead to genetic changes in cells and promote the occurrence of inflammatory diseases or cell death. Nature-inspired polydopamine (PDA) with tailored nanostructures emerges as an ROS scavenger and is considered as an effective approach to inflammation-related diseases. However, the effects of nanoparticle structure on PDA scavenging efficacy and efficiency remain uncovered. In this work, three typical PDA nanoparticles including solid PDA, mesoporous PDA, and hollow PDA are synthesized, and of which physiochemical properties are characterized. Furthermore, their ROS scavenging performance is investigated by in vitro evaluation of radical removal. Among the three nanoparticles, mesoporous PDA is demonstrated to have the highest scavenging capability, mainly due to its specific surface area. Finally, the study on three in vivo inflammation models is constructed. The results confirm that mesoporous PDA is the most potent scavenger of ROS and more effective in reducing reperfusion injury, improving renal function, and preventing periodontitis progression, respectively. Together with the good biosafety and biocompatibility profiles, PDA nanoparticles, mesoporous PDA in particular, can be a promising avenue of ROS scavenging in fight against the inflammatory diseases.

Biomimetic theranostic nanoparticles for effective anticancer therapy and MRI imaging

Cancer remains a leading cause of mortality worldwide, necessitating the development of innovative therapeutic approaches. Nanoparticle-based drug delivery systems have garnered significant interest due to their multifunctionality, offering the potential to enhance cancer treatment efficacy and improve patient tolerability. Membrane-coated drug delivery systems hold great potential for enhancing the therapeutic outcome of nanoparticle-based anticancer therapies. In this study, we report the synthesis of multifunctional iron-functionalized mesoporous polydopamine nanoparticles (MPDAFe NPs). These nanoformulations demonstrate substantial potential for combining efficient drug delivery and magnetic resonance imaging (MRI) and showcase the advantages of biomimetic coating with tumor cell-derived membranes. This coating confers prolonged circulation and improved the targeting capabilities of the nanoparticles. Furthermore, comprehensive biosafety evaluations reveal negligible toxicity to normal cells, while the combined chemo- and phototherapy exhibited significant cytotoxicity towards cancer cells. Additionally, the photothermal effect evaluation highlights the enhanced cytotoxicity achieved through laser irradiation, showcasing the synergistic effects of the nanomaterials and photothermal therapy. Importantly, our chemotherapeutic effect evaluation demonstrates the superior efficacy of doxorubicin-loaded MPDAFe@Mem NPs (cancer cell membrane-coated MPDAFe NPs) in inhibiting cancer cell viability and proliferation, surpassing the potency of free doxorubicin. This study comprehensively investigates theranostic, membrane-coated drug delivery systems, underlining their potential to increase the efficacy of cancer treatment strategies. The multifunctional nature of the iron-functionalized polydopamine nanoparticles allows for efficient drug delivery and imaging capabilities, while the biomimetic coating enhances their biocompatibility and targeting ability. These findings contribute valuable insights towards the development of advanced nanomedicine for improved cancer therapeutics.

Biomimetic “Gemini nanoimmunoregulators” orchestrated for boosted photoimmunotherapy by spatiotemporally modulating PD-L1 and tumor-associated macrophages

A novel strategy of not only stimulating the immune cycle but also modulating the immunosuppressive tumor microenvironment is of vital importance to efficient cancer immunotherapy. Here, a new type of spatiotemporal biomimetic “Gemini nanoimmunoregulators” was engineered to activate robust systemic photoimmunotherapy by integrating the triple-punch of amplified immunogenic cell death (ICD), tumor-associated macrophages (TAMs) phenotype reprogramming and programmed cell death ligand 1 (PD-L1) degradation. The “Gemini nanoimmunoregulators” PM@RM-T7 and PR@RM-M2 were constructed by taking the biocompatible mesoporous polydopamine (mPDA) as nanovectors to deliver metformin (Met) and toll-like receptor 7/8 agonist resiquimod (R848) to cancer cells and TAMs by specific biorecognition via wrapping of red blood cell membrane (RM) inlaid with T7 or M2 peptides. mPDA/Met@RM-T7 (abbreviated as PM@RM-T7) was constructed to elicit an amplified in situ ICD effect through the targeted PTT and effectively stimulated the anticancer immunity. Meanwhile, PD-L1 on the remaining cancer cells was degraded by the burst metformin to prevent immune evasion. Subsequently, mPDA/R848@RM-M2 (abbreviated as PR@RM-M2) specifically recognized TAMs and reset the phenotype from M2 to M1 state, thus disrupting the immunosuppressive microenvironment and further boosting the function of cytotoxic T lymphocytes. This pair of sister nanoimmunoregulators cooperatively orchestrated the comprehensive anticancer activity, which remarkably inhibited the growth of primary and distant 4T1 tumors and prevented malignant metastasis. This study highlights the spatiotemporal cooperative modalities using multiple nanomedicines and provides a new paradigm for efficient cancer immunotherapy against metastatic-prone tumors.