Frontiers in Preparations and Promising Applications of Mesoporous Polydopamine for Cancer Diagnosis and Treatment

Mesoporous polydopamine nanoparticles coated with metal-polyphenol networks for demethylation therapy of lung cancer

The treatment of lung cancer with azacitidine (AZA) is urgently in need of a novel delivery material due to its limitations, including a short half-life, high cytotoxicity, and poor tumor targeting. To overcome these limitations, the coordination of Gallic acid-catechin-gallate with Fe3+ and its encapsulation on the surface of mPDA loaded with AZA (mA@EF) was prepared. mA@EF exhibited a uniform distribution of regular spherical particles with good stability and drug release properties. In cell experiments, mA@EF effectively inhibited cell viability, promoted cellular uptake, and downregulated the expression of DNA methyltransferases. Moreover, mA@EF demonstrated good biosafety. In animal experiments, mA@EF showed strong tumor-targeting and retention activity, and significantly inhibited the growth of tumor. This discovery provided a feasible dosing regimen for AZA treatment in lung cancer patients.

A dual-function hyaluronic acid-encapsulated nanoplatform enables triple GSH depletion for apoptosis-ferroptosis synergistic oncotherapy

Ferroptosis has emerged as an alternative strategy to eradicate apoptosis-resistant tumor cells. However, the hypoxia and redox homeostasis in tumor microenvironment (TME) hinder effective ferroptosis induction. Herein, we report a multifunctional MnO2-nanoclusters-decorated Cu2+-doped mussel-inspired mesoporous polydopamine (CM) nanoplatform, which is further engineered by co-loading sorafenib (SRF) and indocyanine green (ICG) with the help of a cargo-loading and targeting-capable hyaluronic acid (HA) shell to obtain CMMSIH. Once accumulating in tumors, the MnO2 nanoclusters catalyze glutathione (GSH) oxidation and H2O2 decomposition to deplete intracellular GSH and alleviate hypoxia. The released SRF and exposed CM core are further devoted to inhibiting de novo GSH synthesis and scavenging endogenous GSH, respectively. This triple-modal GSH depletion inactivates intracellular glutathione peroxidase 4 (GPX4), thereby amplifying the potential for ferroptosis. Besides, the Cu2+-mediated fenton-like reaction and ICG-based photodynamic process generate abundant reactive oxygen species (ROS), further amplified by photothermal effect and MnO2-supplied oxygen of CMMSIH. This design synergistically achieves GPX4 inactivation, hypoxia alleviation and ROS accumulation, thus disrupting intracellular redox homeostasis and ultimately triggering the ferroptotic and apoptotic death of tumor cells. In vivo studies demonstrate that CMMSIH nanoplatform inhibits tumor growth without systemic toxicity, offering a promising multimodal strategy to overcome the limitations of TME.

Tumor Microenvironment-Responsive Nanodrug for Embolotherapy and Enhanced Chemotherapy

Embolotherapy is an effective antitumor method, which essentially blocks the oxygen supply and induces hypoxia to treat tumors; however, traditional practices demand high expertise and harbor risks of complications. This study presents a mesoporous polydopamine-based (MPDA) drug delivery platform modified by engineered fusion proteins, which can specifically embolize tumor blood vessels and deliver the hypoxia-activated prodrug tirapazamine (TPZ). The fusion protein consists of an affibody targeting HER-2, a substrate for MMP-2, an RGD tripeptide, and a truncated tissue factor (tTF), which is then connected to MPDA loaded with TPZ. This nanodrug can actively target HER-2, interact with MMP-2 in the tumor microenvironment (TME), and embolize blood vessels; then, under TME acidic circumstances, MPDA releases TPZ, which is activated by hypoxia aggravated by embolization, and kills tumors. This embolization strategy, which is activated only under specific conditions, is extremely safe, and it compensates for the inadequacies of conventional embolization therapy, while also addressing the issue of hypoxia deficiency in hypoxia-activated prodrug therapy.

A Multifunctional Nanodrug Co-Delivering VEGF-siRNA and Dexamethasone for Synergistic Therapy in Ocular Neovascular Diseases

Introduction

Oxidant stress, abnormal angiogenesis, and inflammation are three key factors contributing to the development of ocular neovascular diseases (ONDs). This study aims to develop a multifunctional nanodrug, DEX@MPDA-Arg@Si (DMAS), which integrates mesoporous polydopamine, vascular endothelial growth factor (VEGF)-siRNA, and dexamethasone (DEX) to address these therapeutic targets.

Methods

Physicochemical properties of DMAS were measured using transmission electron microscopy and a nanoparticle size analyzer. The encapsulation efficiency and drug loading capacity of DMAS were measured using a UV-visible spectrophotometer. The in vivo therapeutic efficacy and ocular safety of DMAS were evaluated using three established mouse models, including the alkali burn-induced corneal neovascularization (CoNV) model, the oxygen-induced retinopathy (OIR) model, and the laser-induced choroidal neovascularization (CNV) model.

Results

The DMAS nanoparticles demonstrated a uniform bowl-like shape with an average size of 264.9 ± 2.5 nm and a zeta potential of -28.2 ± 4.2 mV. They exhibited high drug-loading efficiency (36.04 ± 3.60% for DEX) and excellent biocompatibility. In vitro studies confirmed its potent antioxidant, anti-inflammatory, and anti-apoptotic properties. In vivo, DMAS treatment led to significant therapeutic effects across all models. It effectively inhibited CoNV, promoted corneal repair, and modulated inflammation in the alkali burn model. In the OIR model, DMAS reduced retinal neovascularization by decreasing VEGF expression. In the laser-induced CNV model, it significantly reduced the CNV area and lesion thickness.

Conclusion

This research developed a multifunctional nanodrug, DMAS, capable of co-delivering VEGF-siRNA and DEX, offering synergistic therapeutic benefits for treating ONDs. The DMAS nanodrug demonstrates promising anti-inflammatory, antioxidative, and anti-angiogenic effects, highlighting its potential as a versatile and effective treatment for multiple ocular conditions.

Nanoparticles targeting OPN loaded with BY1 inhibits vascular restenosis by inducing FTH1-dependent ferroptosis in vascular smooth muscle cells

Vascular restenosis following angioplasty continues to pose a significant challenge. The heterocyclic trioxirane compound [1, 3, 5-tris((oxiran-2-yl)methyl)-1, 3, 5-triazinane-2, 4, 6-trione (TGIC)], known for its anticancer activity, was utilized as the parent ring to conjugate with a non-steroidal anti-inflammatory drug, resulting in the creation of the spliced conjugated compound BY1. We found that BY1 induced ferroptosis in VSMCs as well as in neointima hyperplasia. Furthermore, ferroptosis inducers amplified BY1-induced cell death, while inhibitors mitigated it, indicating the contribution of ferroptosis to BY1-induced cell death. Additionally, we established that ferritin heavy chain1 (FTH1) played a pivotal role in BY1-induced ferroptosis, as evidenced by the fact that FTH1 overexpression abrogated BY1-induced ferroptosis, while FTH1 knockdown exacerbated it. Further study found that BY1 induced ferroptosis by enhancing the NCOA4-FTH1 interaction and increasing the amount of intracellular ferrous. We compared the effectiveness of various administration routes for BY1, including BY1-coated balloons, hydrogel-based BY1 delivery, and nanoparticles targeting OPN loaded with BY1 (TOP@MPDA@BY1) for targeting proliferated VSMCs, for prevention and treatment of the restenosis. Our results indicated that TOP@MPDA@BY1 was the most effective among the three administration routes, positioning BY1 as a highly promising candidate for the development of drug-eluting stents or treatments for restenosis.

Hydrogels in Gene Delivery Techniques for Regenerative Medicine and Tissue Engineering

Hydrogels are 3D networks swollen with water. They are biocompatible, strong, and moldable and are emerging as a promising biomedical material for regenerative medicine and tissue engineering to deliver therapeutic genes. The excellent natural extracellular matrix simulation properties of hydrogels enable them to be co-cultured with cells or enhance the expression of viral or non-viral vectors. Its biocompatibility, high strength, and degradation performance also make the action process of carriers in tissues more ideal, making it an ideal biomedical material. It has been shown that hydrogel-based gene delivery technologies have the potential to play therapy-relevant roles in organs such as bone, cartilage, nerve, skin, reproductive organs, and liver in animal experiments and preclinical trials. This paper reviews recent articles on hydrogels in gene delivery and explains the manufacture, applications, developmental timeline, limitations, and future directions of hydrogel-based gene delivery techniques.

Polydopamine-containing nano-systems for cancer multi-mode diagnoses and therapies: A review

Polydopamine (PDA) has fascinating properties such as inherent biocompatibility, simple preparation, strong near-infrared absorption, high photothermal conversion efficiency, and strong metal ion chelation, which have catalyzed extensive research in PDA-containing multifunctional nano-systems particularly for biomedical applications. Thus, it is imperative to overview synthetic strategies of various PDA-containing nanoparticles (NPs) for state-of-the-art cancer multi-mode diagnoses and therapies applications, and offer a timely and comprehensive summary. In this review, we will focus on the synthetic approaches of PDA NPs, and summarize the construction strategies of PDA-containing NPs with different structure forms. Additionally, the application of PDA-containing NPs in bioimaging such as photoacoustic imaging, fluorescence imaging, magnetic resonance imaging and other imaging modalities will be reviewed. We will especially offer an overview of their therapeutic applications in tumor chemotherapy, photothermal therapy, photodynamic therapy, photocatalytic therapy, sonodynamic therapy, radionuclide therapy, gene therapy, immunotherapy and combination therapy. At the end, the current trends, limitations and future prospects of PDA-containing nano-systems will be discussed. This review aims to provide guidelines for new scientists in the field of how to design PDA-containing NPs and what has been achieved in this area, while offering comprehensive insights into the potential of PDA-containing nano-systems used in cancer diagnosis and treatment.

Hollow-polydopamine-nanocarrier-based near-infrared-light/pH-responsive drug delivery system for diffuse alveolar hemorrhage treatment

Introduction: Diffuse alveolar hemorrhage (DAH) is a serious complication caused by systemic lupus erythematosus (SLE). Tissue damage and changes in immune response are all associated with excessive free radical production. Therefore, removing excess reactive oxygen species are considered a feasible scheme for diffuse alveolar hemorrhage treatment. Cyclophosphamide is often used as the main therapeutic drug in clinics. However, CTX carries a high risk of dose-increasing toxicity, treatment intolerance, and high recurrence rate. The combination of therapeutic drugs and functional nanocarriers may provide an effective solution. PDA is rich in phenolic groups, which can remove the reactive oxygen species generated in inflammatory reactions, and can serve as excellent free radical scavengers. Methods: We developed a hollow polydopamine (HPDA) nanocarrier loaded with CTX by ionization to prepare the novel nanoplatform, CTX@HPDA, for DAH treatment. The monodisperse silica nanoparticles were acquired by reference to the typical Stober method. PDA was coated on the surface of SiO₂ by oxidation self-polymerization method to obtain SiO₂@PDA NPs. Then, HPDA NPs were obtained by HF etching. Then HPDA was loaded with CTX by ionization to prepare CTX@HPDA. Then we tested the photothermal effect, animal model therapeutics effect, and biosafety of CTX@HPDA. Results: Material tests showed that the CTX@ HPDA nanoplatform had a uniform diameter and could release CTX in acidic environments. The vitro experiments demonstrated that CTX@HPDA has good photothermal conversion ability and photothermal stability. Animal experiments demonstrated that the CTX@HPDA nanoplatform had good biocompatibility. The nanoplatform can dissociate in acidic SLE environment and trigger CTX release through photothermal conversion. Combining HPDA, which scavenges oxygen free radicals, and CTX, which has immunosuppressive effect, can treat pulmonary hemorrhage in SLE. Micro-CT can be used to continuously analyze DAH severity and lung changes in mice after treatment. The pulmonary exudation in the various treatment groups improved to varying degrees. Discussion: In this study, we report a photothermal/PH-triggered nanocarrier (CTX@HPDA) for the precise treatment of SLE-DAH. CTX@HPDA is a simple and efficient nanocarrier system for DAH therapy. This work provides valuable insights into SLE treatment.

Enzyme functionalized PEOz modified magnetic polydopamine with enhanced penetration for cascade-augmented synergistic tumor therapy

In recent years, reactive oxygen species (ROS)-mediated cancer therapies have been widely recognized for their high selectivity and good biological safety. However, due to the difficulties of endogenous tumor microenvironment (TME), penetration of tumor tissues and integration of multimodal tumor ablation, the treatment with traditional therapies could not achieve satisfactory tumor inhibition effects. Here, a doxorubicin (DOX)-glucose oxidase (GOx) dual-loaded and poly (2-ethyl-2-oxazoline) (PEOz) decorated magnetic polydopamine nanoparticles (Fe₃O₄-DOX@PDA-GOx@PEOz, FDPGP) were constructed for tumor ablation. GOx-mediated cascade enzyme reactions could amplify oxidative stress damage and further synergistically inhibit breast cancer. Its pH-responsive charge reversal, drug-controlled release, photothermal, and cascade reactions were evaluated through extracellular experiments. Cellular uptake, cell cytotoxicity, tumor penetration and therapeutic efficacy of FDPGP were investigated through intracellular experiments. Finally, in vivo distribution, photothermal, synergistic antitumor therapeutic effect and biosafety were evaluated comprehensively by in vivo experiments. Excitingly, outstanding tumor enrichment and penetration, superior anticancer effects and biosafety were achieved by the combination of photothermal therapy (PTT)/starvation therapy (ST)/chemodynamic therapy (CDT)/chemotherapy (CT). As such, the FDPGP nanoplatform provides a new insight into the development of collaboratively multimodal enhanced tumor therapy.