A flexible bowl-shaped magnetic assembly for multifunctional gene delivery systems

Recent progress of iron-based nanomaterials in gene delivery and tumor gene therapy

Gene therapy aims to modify or manipulate gene expression and change the biological characteristics of living cells to achieve the purpose of treating diseases. The safe, efficient, and stable expression of exogenous genes in cells is crucial for the success of gene therapy, which is closely related to the vectors used in gene therapy. Currently, gene therapy vectors are mainly divided into two categories: viral vectors and non-viral vectors. Viral vectors are widely used due to the advantages of persistent and stable expression, high transfection efficiency, but they also have certain issues such as infectivity, high immunological rejection, randomness of insertion mutation, carcinogenicity, and limited vector capacity. Non-viral vectors have the advantages of non-infectivity, controllable chemical structure, and unlimited vector capacity, but the transfection efficiency is low. With the rapid development of nanotechnology, the unique physicochemical properties of nanomaterials have attracted increasing attention in the field of drug and gene delivery. Among many nanomaterials, iron-based nanomaterials have attracted much attention due to their superior physicochemical properties, such as Fenton reaction, magnetic resonance imaging, magnetothermal therapy, photothermal therapy, gene delivery, magnetically-assisted drug delivery, cell and tissue targeting, and so on. In this paper, the research progress of iron-based nanomaterials in gene delivery and tumor gene therapy is reviewed, and the future application direction of iron-based nanomaterials is further prospected.

Physical-Chemical Coupling Coassembly Approach to Branched Magnetic Mesoporous Nanochains with Adjustable Surface Roughness

Self-assembly processes triggered by physical or chemical driving forces have been applied to fabricate hierarchical materials with subtle nanostructures. However, various physicochemical processes often interfere with each other, and their precise control has remained a great challenge. Here, in this paper, a rational synthesis of 1D magnetite-chain and mesoporous-silica-nanorod (Fe3O4&mSiO2) branched magnetic nanochains via a physical-chemical coupling coassembly approach is reported. Magnetic-field-induced assembly of magnetite Fe3O4 nanoparticles and isotropic/anisotropic assembly of mesoporous silica are coupled to obtain the delicate 1D branched magnetic mesoporous nanochains. The nanochains with a length of 2-3 µm in length are composed of aligned Fe3O4@mSiO2 nanospheres with a diameter of 150 nm and sticked-out 300 nm long mSiO2 branches. By properly coordinating the multiple assembly processes, the density and length of mSiO2 branches can well be adjusted. Because of the unique rough surface and length in correspondence to bacteria, the designed 1D Fe3O4&mSiO2 branched magnetic nanochains show strong bacterial adhesion and pressuring ability, performing bacterial inhibition over 60% at a low concentration (15 µg mL-1). This cooperative coassembly strategy deepens the understanding of the micro-nanoscale assembly process and lays a foundation for the preparation of the assembly with adjustable surface structures and the subsequent construction of complex multilevel structures.

Gene and Photothermal Combination Therapy: Principle, Materials, and Amplified Anticancer Intervention

Gene therapy (GT) and photothermal therapy (PTT) have emerged as promising alternatives to chemotherapy and radiotherapy for cancer treatment, offering noninvasiveness and reduced side effects. However, their efficacy as standalone treatments is limited. GT exhibits slow response rates, while PTT is confined to local tumor ablation. The convergence of GT and PTT, known as GT-PTT, facilitated by photothermal gene nanocarriers, has attracted considerable attention across various disciplines. In this integrated approach, GT reciprocates PTT by sensitizing cellular response to heat, while PTT benefits GT by improving gene translocation, unpacking, and expression. Consequently, this integration presents a unique opportunity for cancer therapy with rapid response and improved effectiveness. Extensive efforts over the past few years have been dedicated to the development of GT-PTT, resulting in notable achievements and rapid progress from the laboratory to potential clinical applications. This comprehensive review outlines recent advances in GT-PTT, including synergistic mechanisms, material systems, imaging-guided therapy, and anticancer applications. It also explores the challenges and future prospects in this nascent field. By presenting innovative ideas and insights into the implementation of GT-PTT for enhanced cancer therapy, this review aims to inspire further progress in this promising area of research.

Polymeric Bowl-Shaped Nanoparticles: Hollow Structures with a Large Opening on the Surface

Polymeric bowl-shaped nanoparticles (BNPs) are anisotropic hollow structures with large openings on the surface, which have shown advantages such as high specific area and efficient encapsulation, delivery and release of large-sized cargoes on demand compared to solid nanoparticles or closed hollow structures. Several strategies have been developed to prepare BNPs based on either template or template-free methods. For instance, despite the widely used self-assembly strategy, alternative methods including emulsion polymerization, swelling and freeze-drying of polymeric spheres, and template-assisted approaches have also been developed. It is attractive but still challenging to fabricate BNPs due to their unique structural features. However, there is still no comprehensive summary of BNPs up to now, which significantly hinders the further development of this field. In this review, the recent progress of BNPs will be highlighted from the perspectives of design strategies, preparation methods, formation mechanisms, and emerging applications. Moreover, the future perspectives of BNPs will also be proposed.

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.

Cationic polymer synergizing with a disulfide-containing enhancer achieved efficient nucleic acid and protein delivery

To improve the efficiency of nucleic acid and protein delivery by cationic polymers, there is a trade-off between increasing the positive charge density of cationic polymers and decreasing cytotoxicity. In this work, a strategy to introduce multiple interactions between the cell membrane and a delivery system based on cationic polymers was proposed. A novel delivery system consisting of PEI1.8k and an enhancer (LA-RT) was fabricated. The introduction of LA-RT contributed to multiple interactions between the delivery system and the cell membrane including electrostatic interactions, hydrogen bonding, hydrophobic interaction, and dynamic sulfur exchange reactions, which enabled efficient intracellular delivery of nucleic acids and proteins. For nucleic acid delivery, plasmid DNA and mRNA were loaded to realize CRISPR/Cas 9 gene editing in vivo and protein expression in vivo, respectively. For protein delivery, the delivery system carrying OVA protein and CpG formed a nano-vaccine, which induced enhanced humoral and cellular immunity in vivo. In addition, the delivery system based on PEI1.8k revealed negligible cytotoxicity. This work provided a novel strategy to prepare efficient delivery systems based on cationic polymers via the introduction of a multifunctional enhancer.

Recent Advances in Functionalized Nanoparticles in Cancer Theranostics

Cancer theranostics is the combination of diagnosis and therapeutic approaches for cancer, which is essential in personalized cancer treatment. The aims of the theranostics application of nanoparticles in cancer detection and therapy are to reduce delays in treatment and hence improve patient care. Recently, it has been found that the functionalization of nanoparticles can improve the efficiency, performance, specificity and sensitivity of the structure, and increase stability in the body and acidic environment. Moreover, functionalized nanoparticles have been found to possess a remarkable theranostic ability and have revolutionized cancer treatment. Each cancer treatment modality, such as MRI-guided gene therapy, MRI-guided thermal therapy, magnetic hyperthermia treatment, MRI-guided chemotherapy, immunotherapy, photothermal and photodynamic therapy, has its strengths and weaknesses, and combining modalities allows for a better platform for improved cancer control. This is why cancer theranostics have been investigated thoroughly in recent years and enabled by functionalized nanoparticles. In this topical review, we look at the recent advances in cancer theranostics using functionalized nanoparticles. Through understanding and updating the development of nanoparticle-based cancer theranostics, we find out the future challenges and perspectives in this novel type of cancer treatment.

Mitochondria-Targeted Degradable Nanocomposite Combined with Laser and Ultrasound for Synergistic Tumor Therapies

Although the development of safe and efficient cancer therapeutic agents is essential, this process remains challenging. In this study, a mitochondria-targeted degradable nanoplatform (PDA-MnO₂-IR780) for synergistic photothermal, photodynamic, and sonodynamic tumor treatment was investigated. PDA-MnO₂-IR780 exhibits superior photothermal properties owing to the integration of polydopamine, MnO₂, and IR780. IR780, a photosensitizer and sonosensitizer, was used for photodynamic therapy and sonodynamic therapy. When PDA-MnO₂-IR780 was delivered to the tumor site, MnO₂ was decomposed by hydrogen peroxide, producing Mn²⁺ and oxygen. Meanwhile, alleviating tumor hypoxia promoted the production of reactive oxygen species during photodynamic therapy and sonodynamic therapy. Moreover, large amounts of reactive oxygen species could reduce the expression of heat shock proteins and increase the heat sensitivity of tumor cells, thereby improving the photothermal treatment effect. In turn, hyperthermia caused by photothermal therapy accelerated the production of reactive oxygen species in photodynamic therapy. IR780 selectively accumulation in mitochondria also promoted tumor apoptosis. In this system, the mutual promotion of photothermal therapy and photodynamic therapy/sonodynamic therapy had an enhanced therapeutic effect. Moreover, the responsive degradable characteristic of PDA-MnO₂-IR780 in the tumor microenvironment ensured excellent biological safety. These results reveal a great potential of PDA-MnO₂-IR780 for safe and highly-efficiency synergistic therapy for cancer.

Dual-Targeted Fe₃O₄@MnO₂ Nanoflowers for Magnetic Resonance Imaging-Guided Photothermal-Enhanced Chemodynamic/Chemotherapy for Tumor

The construction of high-efficiency tumor theranostic platform will be of great interest in the treatment of cancer patients; however, significant challenges are associated with developing such a platform. In this study, we developed high-efficiency nanotheranostic agent based on ferroferric oxide, manganese dioxide, hyaluronic acid and doxorubicin (FMDH-D NPs) for dual targeting and imaging guided synergetic photothermal-enhanced chemodynamic/chemotherapy for cancer, which improved the specific uptake of drugs at tumor site by the dual action of CD44 ligand hyaluronic acid and magnetic nanoparticles guided by magnetic force. Under the acidic microenvironment of cancer cells, FMDH-D could be decomposed into Mn²⁺ and Fe²⁺ to generate •OH radicals by triggering a Fenton-like reaction and responsively releasing doxorubicin to kill cancer cells. Meanwhile, alleviating tumor hypoxia improved the efficacy of chemotherapy in tumors. The photothermal properties of FMDH generated high temperatures, which further accelerated the generation of reactive oxygen species, and enhanced effects of chemodynamic therapy. Furthermore, FMDH-D NPs proved to be excellent T₁/T₂-weighted magnetic resonance imaging contrast agents for monitoring the tumor location. These results confirmed the considerable potential of FMDH-D NPs in a highly efficient synergistic therapy platform for cancer treatment.

MnO2 nanoflowers as a multifunctional nano-platform for enhanced photothermal/photodynamic therapy and MR imaging

Photodynamic therapy (PDT) has been regarded as a promising strategy for tumor therapy. However, heterogeneous tumor microenvironments severely limit the efficacy of photodynamic therapy. In this work, a multifunctional theranostic platform (MnO2-SiO2-APTES&Ce6 (MSA&C)) was fabricated based on MnO2 nanoflowers, which afforded MRI-guided synergistic therapy incorporating PDT and second near-infrared window (NIR-II) photothermal therapy (PTT). Herein, MnO2 nanoflowers are first proposed as a NIR-II photothermal agent. In the MSA&C system, MnO2 nanoflowers were employed for effective photosensitizer loading, relieving tumor hypoxia, and NIR-II PTT and tumor-specific imaging. The large amount of photosensitizer, reduced tumor hypoxia, and hyperthermia all contributed to the improvement of PDT. The quantity of reactive oxygen species (ROS) generated during PDT in turn down-regulated the expression of heat shock proteins (HSP 70), thereby improving photothermal performance. Positively charged (3-aminopropyl)triethoxysilane (APTES) was used to promote cellular uptake, further improving treatment efficiency. In this system, the MSA&C nanoflowers can not only alleviate tumor hypoxia, but they also obviously induce cell apoptosis under laser irradiation through a ROS- and hyperthermia-mediated mechanism, thereby leading to remarkable tumor growth inhibition. Furthermore, the Mn2+ ions generated during treatment can be explored for MR imaging, and this could be used to finally realize MRI-guided enhanced PDT/PTT.

Versatile Types of Cyclodextrin-Based Nucleic Acid Delivery Systems

Nowadays, nucleic acid therapy has become a promising way for the treatment of various malignant diseases. Cyclodextrin (CD)-based nucleic acid delivery systems have attracted widespread attention due to the favorable chemical structures and excellent biological properties of CD. Recently, a variety of CD-based nucleic acid delivery systems has been designed according to the different functions of CD for flexible gene therapies. In this review, the construction strategies and biomedical applications of CD-based nucleic acid delivery systems are mainly focused on. The review begins with an introduction to the synthesis and properties of simple CD-grafted polycations. Thereafter, CD-related supramolecular assemblies based on different guest components are discussed in detail. Finally, different CD-based organic/inorganic nanohybrids and their relevant functions are demonstrated. It is hoped that this brief review will motivate the delicate design of CD-based nucleic acid delivery systems for potential clinical applications.

In vivo gene delivery mediated by non-viral vectors for cancer therapy

Gene therapy by expression constructs or down-regulation of certain genes has shown great potential for the treatment of various diseases. The wide clinical application of nucleic acid materials dependents on the development of biocompatible gene carriers. There are enormous various compounds widely investigated to be used as non-viral gene carriers including lipids, polymers, carbon materials, and inorganic structures. In this review, we will discuss the recent discoveries on non-viral gene delivery systems. We will also highlight the in vivo gene delivery mediated by non-viral vectors to treat cancer in different tissue and organs including brain, breast, lung, liver, stomach, and prostate. Finally, we will delineate the state-of-the-art and promising perspective of in vivo gene editing using non-viral nano-vectors.