The gene transfection and endocytic uptake pathways mediated by PEGylated PEI-entrapped gold nanoparticles

PEI-based functional materials: Fabrication techniques, properties, and biomedical applications

Cationic polymers have recently attracted considerable interest as research breakthroughs for various industrial and biomedical applications. They are particularly interesting due to their highly positive charges, acceptable physicochemical properties, and ability to undergo further modifications, making them attractive candidates for biomedical applications. Polyethyleneimines (PEIs), as the most extensively utilized polymers, are one of the valuable and prominent classes of polycations. Owing to their flexible polymeric chains, broad molecular weight (MW) distribution, and repetitive structural units, their customization for functional composites is more feasible. The specific beneficial attributes of PEIs could be introduced by purposeful functionalization or modification, long service life, biocompatibility, and distinct geometry. Therefore, PEIs have significant potential in biotechnology, medicine, and bioscience. In this review, we present the advances in PEI-based nanomaterials, their transfection efficiency, and their toxicity over the past few years. Furthermore, the potential and suitability of PEIs for various applications are highlighted and discussed in detail. This review aims to inspire readers to investigate innovative approaches for the design and development of next-generation PEI-based nanomaterials possessing cutting-edge functionalities and appealing characteristics.

Unsymmetrical Low-Generation Cationic Phosphorus Dendrimers as a Nonviral Vector to Deliver MicroRNA for Breast Cancer Therapy

The development of nonviral dendritic polymers with a simple molecular backbone and great gene delivery efficiency to effectively tackle cancer remains a great challenge. Phosphorus dendrimers or dendrons are promising vectors due to their structural uniformity, rigid molecular backbones, and tunable surface functionalities. Here, we report the development of a new low-generation unsymmetrical cationic phosphorus dendrimer bearing 5 pyrrolidinium groups and one amino group as a nonviral gene delivery vector. The created AB5-type dendrimers with simple molecular backbone can compress microRNA-30d (miR-30d) to form polyplexes with desired hydrodynamic sizes and surface potentials and can effectively transfect miR-30d to cancer cells to suppress the glycolysis-associated SLC2A1 and HK1 expression, thus significantly inhibiting the migration and invasion of a murine breast cancer cell line in vitro and the corresponding subcutaneous tumor mouse model in vivo. Such unsymmetrical low-generation phosphorus dendrimers may be extended to deliver other genetic materials to tackle other diseases.

Revisiting of Properties and Modified Polyethylenimine-Based Cancer Gene Delivery Systems

A new era of medical technology in cancer treatment is a directly specific modification of gene expression in tumor cells by nucleic acid delivery. Currently, the main challenge to achieving this goal is to find a non-toxic, safe, and effective strategy for gene transfer to cancer cells. Synthetic composites based on cationic polymers have historically been favored in bioengineering due to their ability to mimic bimolecular structures. Among them, polyethylenimines (PEIs) with superior properties such as a wide range of molecular weight and a flexible structure may propel the development of functional combinations in the biomedical and biomaterial fields. Here, in this review, we will focus on the recent progressions in the formulation optimization of PEI-based polyplex in gene delivery to treat cancer. Also, the effect of PEI's intrinsic characteristics such as structure, molecular weight, and positive charges which influence the gene delivery efficiency will be discussed.

Targeted delivery of miR-34a-5p by phenylborate-coupled polyethylenimide nanocarriers for anti-KSHV treatment

Kaposi's sarcoma-associated herpesvirus (KSHV) can infect a variety of cells and cause malignant tumors. At present, the use of microRNA (miRNA) for anti-KSHV is a promising treatment strategy, but the instability and non-specific uptake of miRNA still limit its use in the treatment of KSHV. In the present study, we constructed a nano-drug delivery system employing chemical grafting and electrostatic adsorption to solve the problems of easy degradation and low cell uptake of miRNA during direct administration. This nano-drug delivery system is to graft 4-carboxyphenylboric acid (PBA) and lauric acid (LA) onto polyethylenimine (PEI) through amidation reaction, and then prepare cationic copolymer nanocarriers (LA-PEI-PBA). The drug-carrying nanocomplex LA-PEI-PBA/miR-34a-5p was formed after further electrostatic adsorption of miR-34a-5p on the carrier and could protect miR-34a-5p from nuclease and serum degradation. Modification of the drug-carrying nanocomplex LA-PEI-PBA/miR-34a-5p by targeted molecule PBA showed effective uptake, increase in the level of miR-34a-5p, and inhibition of cell proliferation and migration in KSHV-infected cells. In addition, the drug-carrying nanocomplex could also significantly reduce the expression of KSHV lytic and latent genes, achieving the purpose of anti-KSHV treatment. In conclusion, these cationic copolymer nanocarriers with PBA targeting possess potential applications in nucleic acid delivery and anti-KSHV therapy.

Optimal delivery strategies for nanoparticle-mediated mRNA delivery

Messenger RNA (mRNA) has emerged as a new and efficient agent for the treatment of various diseases. The success of lipid nanoparticle-mRNA against the novel coronavirus (SARS-CoV-2) pneumonia epidemic has proved the clinical potential of nanoparticle-mRNA formulations. However, the deficiency in the effective biological distribution, high transfection efficiency and good biosafety are still the major challenges in clinical translation of nanomedicine for mRNA delivery. To date, a variety of promising nanoparticles have been constructed and then gradually optimized to facilitate the effective biodistribution of carriers and efficient mRNA delivery. In this review, we describe the design of nanoparticles with an emphasis on lipid nanoparticles, and discuss the manipulation strategies for nanoparticle-biology (nano-bio) interactions for mRNA delivery to overcome the biological barriers and improve the delivery efficiency, because the specific nano-bio interaction of nanoparticles usually remoulds the biomedical and physiological properties of the nanoparticles especially the biodistribution, mechanism of cellular internalization and immune response. Finally, we give a perspective for the future applications of this promising technology. We believe that the regulation of nano-bio interactions would be a significant breakthrough to improve the mRNA delivery efficiency and cross biological barriers. This review may provide a new direction for the design of nanoparticle-mediated mRNA delivery systems.

Nanosystems for gene therapy targeting brain damage caused by viral infections

Several human pathogens can cause long-lasting neurological damage. Despite the increasing clinical knowledge about these conditions, most still lack efficient therapeutic interventions. Gene therapy (GT) approaches comprise strategies to modify or adjust the expression or function of a gene, thus providing therapy for human diseases. Since recombinant nucleic acids used in GT have physicochemical limitations and can fail to reach the desired tissue, viral and non-viral vectors are applied to mediate gene delivery. Although viral vectors are associated to high levels of transfection, non-viral vectors are safer and have been further explored. Different types of nanosystems consisting of lipids, polymeric and inorganic materials are applied as non-viral vectors. In this review, we discuss potential targets for GT intervention in order to prevent neurological damage associated to infectious diseases as well as the role of nanosized non-viral vectors as agents to help the selective delivery of these gene-modifying molecules. Application of non-viral vectors for delivery of GT effectors comprise a promising alternative to treat brain inflammation induced by viral infections.

Polyethyleneimine-Based Drug Delivery Systems for Cancer Theranostics

With the development of nanotechnology, various types of polymer-based drug delivery systems have been designed for biomedical applications. Polymer-based drug delivery systems with desirable biocompatibility can be efficiently delivered to tumor sites with passive or targeted effects and combined with other therapeutic and imaging agents for cancer theranostics. As an effective vehicle for drug and gene delivery, polyethyleneimine (PEI) has been extensively studied due to its rich surface amines and excellent water solubility. In this work, we summarize the surface modifications of PEI to enhance biocompatibility and functionalization. Additionally, the synthesis of PEI-based nanoparticles is discussed. We further review the applications of PEI-based drug delivery systems in cancer treatment, cancer imaging, and cancer theranostics. Finally, we thoroughly consider the outlook and challenges relating to PEI-based drug delivery systems.

Theranostic silk sericin/SPION nanoparticles for targeted delivery of ROR1 siRNA: Synthesis, characterization, diagnosis and anticancer effect on triple-negative breast cancer

Triple-negative breast cancer (TNBC) has the worst prognosis among all breast cancer subtypes. The lack of proper treatments prompted scientists to find a practical targeted therapy to treat this type of tumor. Based on previous studies, tyrosine kinase-like orphan receptor (ROR1) is overexpressed in TNBC cells. Here, we designed a system consisting of superparamagnetic iron oxide nanoparticles (SPIONs) decorated with silk sericin (SS NPs) for the targeted delivery of ROR1 siRNA, a gene silencer to knockdown the expression of human ROR1 gene. NPs exhibited spherical shape of about 193 nm with acceptable properties both in vitro and in vivo. The apoptosis study showed significant death of MDA-MB-231 cells after 24 h treatment with the prepared NPs. The real-time PCR study also demonstrated an almost complete shutdown of ROR1 expression. Guided by magnetic field, enhanced accumulation of NPs was observed in breast tumors induced by 4T1 cells in BALB/c mice. Histological evaluation of the tumor exhibited necrosis 14 days post-treatment with the siRNA-loaded NPs; whereas, the untreated tumor was proliferating. Also, the tumor growth rate was significantly decreased after treatment with siRNA-loaded NPs in vivo. In conclusion, the prepared delivery system could be considered as a potential therapeutic strategy for treating TNBC.

Preparation of PEI-modified nanoparticles by dopamine self-polymerization for efficient DNA delivery

Achieving efficient and safe gene delivery is great of significance to promote the development of gene therapy. In this work, a polydopamine (PDA) layer was coated on the surface of Fe₃ O₄ nanoparticles (NPs) by dopamine (DA) self-polymerization, and then magnetic Fe₃ O₄ NPs were prepared by the Michael addition between amino groups in polyethyleneimine (PEI) and PDA. The prepared Fe₃ O₄ NPs (named Fe₃ O₄ @PDA@PEI) were characterized by FTIR, atomic force microscopy (AFM) and scanning electron microscope (SEM). As an efficient and safe gene carrier, the potential of Fe₃ O₄ @PDA@PEI was evaluated by agarose gel electrophoresis, MTT assay, fluorescence microscopy, flow cytometry. The results shows that the Fe₃ O₄ @PDA@PEI NPs is stable hydrophilic nanoparticles with a particle size of 50-150 nm. It can efficiently condense DNA at low N/P ratios and protect it from nuclease degradation. In addition, the Fe₃ O₄ @PDA@PEI NPs has higher safety than PEI. Further, the Fe₃ O₄ @PDA@PEI/DNA polyplexes could be effectively absorbed by cells and successfully transfected, and exhibit higher cellular uptake and gene transfection efficiency than PEI/DNA polyplexes. The findings indicate that the Fe₃ O₄ @PDA@PEI NPs has the potential to be developed into a novel gene vector. This article is protected by copyright. All rights reserved.

New paradigm in combination therapy of siRNA with chemotherapeutic drugs for effective cancer therapy

Chemotherapeutics drugs play a pivotal role in the treatment of cancer. However, many issues generate by chemotherapy drugs, including unfavorable harm to healthy cells and multidrug resistance (MDR), persist and have a negative impact on therapeutic outcomes. When compared to monotherapy, combination cancer therapy has many advantages, like improving efficacy through synergistic effects and overcoming drug resistance. Combination treatment may comprise several chemotherapeutics drugs and combinations of chemotherapeutic drugs with some other therapeutic options such as surgery or radiation. Cancer treatment that utilizes co-delivery strategies with siRNA and chemotherapeutic drugs has been shown to have highly effective antitumor effects in the treatment of many cancers. However, the highly complex mechanisms of chemotherapeutic drugs-siRNA pairs during the co-delivery process have received little attention. The ideal combination of chemotherapeutic drugs with siRNA is very crucial for producing the desirable anticancer effects that would greatly enhance therapeutic efficiency. This review puts an emphasis on the logic for choosing suitable chemotherapeutic drug-siRNA combinations, which may open the way for the co-delivery of chemotherapeutic drugs and siRNA for treating cancer in the clinic. This review summarizes recent breakthrough in the area of diverse mechanism-based chemotherapeutic drugs-siRNA combinations in cancer treatment.

Modification of Branched Polyethyleneimine Using Mesquite Gum for Its Improved Hemocompatibility

In the present study, the modification of branched polyethyleneimine (b-PEI) was carried out using mesquite gum (MG) to improve its hemocompatibility to be used in biomedical applications. In the copolymer synthesis process (carboxymethylated mesquite gum grafted polyethyleneimine copolymer (CBX-MG-PEI), an MG carboxymethylation reaction was initially carried out (carboxymethylated mesquite gum (CBX-MG). Subsequently, the functionalization between CBX-MG and b-PEI was carried out using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as crosslinking agents. The synthesis products were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). Thermogravimetric analysis showed that CBX-MG and CBX-MG-PEI presented a lower decomposition temperature than MG. The CBX-MG-PEI has a high buffer capacity in the pH range of 4 to 7, similar to the b-PEI. In addition, the CBX-MG-PEI showed an improvement in hemocompatibility in comparison with the b-PEI. The results showed a non-hemolytic property at doses lower than 0.1 µg/mL (CBX-MG-PEI). These results allow us to propose that this copolymer be used in transfection, polymeric nanoparticles, and biomaterials due to its physicochemical and hemocompatibility properties.

Special Focus Issue Part II: Recruitment of solid lipid nanoparticles for the delivery of CRISPR/Cas9: primary evaluation of anticancer gene editing

Aim: The CRISPR/Cas9 system is a promising gene-editing tool for various anticancer therapies; however, development of a biocompatible, nonviral and efficient delivery of CRISPR/Cas9 expression systems remains a challenge. Materials & methods: Solid lipid nanoparticles (SLNs) were produced based on pseudo and 3D ternary plots. Obtained SLNs and their complexes with PX458 plasmid DNA were characterized and evaluated in terms of cytotoxicity and transfection efficiency. Results: SLNs were found to be nanosized, monodispersed, stable and nontoxic. Furthermore, they revealed similar transfection efficiency as the positive control. Conclusion: Overall, we have achieved a good SLN basis for CRISPR/Cas9 delivery and have the potential to produce SLNs with targeted anticancer properties by modifying production parameters and components to facilitate translating CRISPR/Cas9 into preclinical studies.

Engineered non-invasive functionalized dendrimer/dendron-entrapped/complexed gold nanoparticles as a novel class of theranostic (radio)pharmaceuticals in cancer therapy

Nanomedicine represents a very significant contribution in current cancer treatment; in addition to surgical intervention, radiation and chemotherapeutic agents that unfortunately also kill healthy cells, inducing highly deleterious and often life-threatening side effects in the patient. Of the numerous nanoparticles used against cancer, gold nanoparticles had been developed for therapeutic applications. Inter alia, a large variety of dendrimers, i.e. soft artificial macromolecules, have turned up as non-viral functional nanocarriers for entrapping drugs, imaging agents, and targeting molecules. This review will provide insights into the design, synthesis, functionalization, and development in biomedicine of engineered functionalized hybrid dendrimer-tangled gold nanoparticles in the domain of cancer theranostic. Several aspects are highlighted and discussed such as 1) dendrimer-entrapped gold(0) hybrid nanoparticles for the targeted imaging and treatment of cancer cells, 2) dendrimer encapsulating gold(0) nanoparticles (Au DENPs) for the delivery of genes, 3) Au DENPs for drug delivery applications, 4) dendrimer encapsulating gold radioactive nanoparticles for radiotherapy, and 5) dendrimer/dendron-complexed gold(III) nanoparticles as technologies to take down cancer cells.

Understanding the influence of experimental factors on bio-interactions of nanoparticles: Towards improving correlation between in vitro and in vivo studies

Bionanotechnology has developed rapidly over the past two decades, owing to the extensive and versatile, functionalities and applicability of nanoparticles (NPs). Fifty-one nanomedicines have been approved by FDA since 1995, out of the many NPs based formulations developed to date. The general conformation of NPs consists of a core with ligands coating their surface, that stabilizes them and provides them with added functionalities. The physicochemical properties, especially the surface composition of NPs influence their bio-interactions to a large extent. This review discusses recent studies that help understand the nano-bio interactions of iron oxide and gold NPs with different surface compositions. We discuss the influence of the experimental factors on the outcome of the studies and, thus, the importance of standardization in the field of nanotechnology. Recent studies suggest that with careful selection of experimental parameters, it is possible to improve the positive correlation between in vitro and in vivo studies. This provides a fundamental understanding of the NPs which helps in assessing their potential toxic side effects and may aid in manipulating them further to improve their biocompatibility and biosafety.

Polyethylenimine-coated gold-magnetic nanoparticles for ADAM10 siRNA delivery in prostate cancer cells

For an effective medical application of therapeutic siRNA, a safe and an efficient delivery system are required. Herein, magnetic nanoparticles (MNPs) have been successfully used as siRNA delivery vehicles. Firstly, MNPs were coated with gold (Au) nanoparticles and then capped with PEI. To improve the biocompatibility of nanoparticles, hyaluronic acid (HA) was coated onto the surface of PEI-Au/Fe nanoparticles. The prepared HA-PEI-Au/Fe3O4 nanoparticles were characterized and found to be uniform and well segregated in TEM analysis. FTIR analysis confirmed that HA was successfully conjugated to PEI. The polymer content in these nanoparticles was relatively higher than PEG coated nanoparticles. Cell viability assay demonstrated that the nanoparticles were relatively biocompatible in nature. ADAM10 siRNA was loaded into the HA-PEI-Au/Fe3O4 nanoparticles and cytotoxicity to prostate cancer (PC3) cells was analyzed. The results indicate that ADAM10 siRNA loaded HA-PEI-Au/Fe3O4 suppress the PC3 cells growth in vitro. Clearly, it could be confirmed that HA-PEI coated Au/Fe3O4 nanoparticles with higher biocompatibility appear to be suitable for intracellular siRNA delivery.

Functionalized gold nanostructures: promising gene delivery vehicles in cancer treatment

Surface-modified gold nanoparticles are recognized as promising gene delivery vehicles in the treatment of cancer owing to their excellent biocompatibility with biomolecules (like DNA or RNA) and their unique optical and structural properties. In this context, this review article focuses on the diverse transfection abilities of the gene to the targeted cell on the basis of different shapes and sizes of gold nanoparticles in order to promote its effective expression for cancer treatment. In addition, recent trends in gold nanoparticle mediated gene silencing, gene delivery, detection and combinatory therapies are highlighted considering their cytotoxic effects on healthy human cells.

Various functions of gold nanoparticles in conjugation with nucleic acids.