Gene transfer into the lung by nanoparticle dextran-spermine/plasmid DNA complexes

Effective mRNA Delivery by Condensation with Cationic Nanogels Incorporated into Liposomes

The challenge in effective delivery of mRNA has been a major hurdle in their development as therapeutics. Herein, we present that the incorporation of cationic nanogels as the condensing material for mRNA into liposomes enables stable and enhanced mRNA delivery to cells in vitro. We prepared dextran-based nanogel particles, which were surface functionalized with oligoarginine peptide (DNPR9) and complexed with mRNA for incorporation into liposomes (LipoDNPR9). The use of DNPR9 with the liposomes resulted in enhanced internalization, as well as a 4-fold increase in transfection of luciferase mRNA when treated with A549 cells in vitro, compared to control liposomes. The enhancement in transfection efficiency was also observed in various cell lines while causing low cytotoxicity. The versatility of the strategy was also investigated by applying DNPR9 for mRNA condensation to ionizable lipid particles, which resulted in an ∼55% increase in transfection. The current development based on nanogel-incorporated liposomes introduces an effective platform for mRNA delivery, while the condensation strategy using DNPR9 can be widely applied for various lipid-based formulations to enhance their efficacy.

Gene Therapy for Regenerative Medicine

The development of biological methods over the past decade has stimulated great interest in the possibility to regenerate human tissues. Advances in stem cell research, gene therapy, and tissue engineering have accelerated the technology in tissue and organ regeneration. However, despite significant progress in this area, there are still several technical issues that must be addressed, especially in the clinical use of gene therapy. The aims of gene therapy include utilising cells to produce a suitable protein, silencing over-producing proteins, and genetically modifying and repairing cell functions that may affect disease conditions. While most current gene therapy clinical trials are based on cell- and viral-mediated approaches, non-viral gene transfection agents are emerging as potentially safe and effective in the treatment of a wide variety of genetic and acquired diseases. Gene therapy based on viral vectors may induce pathogenicity and immunogenicity. Therefore, significant efforts are being invested in non-viral vectors to enhance their efficiency to a level comparable to the viral vector. Non-viral technologies consist of plasmid-based expression systems containing a gene encoding, a therapeutic protein, and synthetic gene delivery systems. One possible approach to enhance non-viral vector ability or to be an alternative to viral vectors would be to use tissue engineering technology for regenerative medicine therapy. This review provides a critical view of gene therapy with a major focus on the development of regenerative medicine technologies to control the in vivo location and function of administered genes.

Targeted delivery of miR-218 via decorated hyperbranched polyamidoamine for liver cancer regression

Hepatocellular carcinoma (HCC) is one of most common causes of cancer death worldwide. MicroRNA (miRNA) replacement gene therapy is a novel approach for HCC management. MiR-218 is a promising tumor suppressor miRNA that is down-regulated in HCC. Here, our aim was the targeted delivery of miR-218 expressing DNA plasmid (pmiR-218) to suppress HCC in vitro and in vivo. Hyperbranched polyamidoamine was synthesized via simple and economically one-pot reaction followed by decoration with lactobionic acid (LA-PAMAM) to selectively deliver and restore miR-218 expression in HCC. In vitro cytotoxicity investigations revealed the high biocompatibility of LA-PAMAM. Furthermore, decoration of hyperbranched polymer with LA moieties enabled LA-PAMAM to deliver pmiR-218 more efficiently to HepG2 cells compared to both PMAMA and naked pmiR-218. Such efficient delivery of miR-218 resulted in suppression of HepG2 proliferation and down-regulation of its oncogenic HOXA1 target. In vivo, LA-PAMAM/pmiR-218 treatment of HCC induced by DEN and CCl₄ in mice leads to an obvious decrease in the number and size of HCC nodules. In addition, LA-PAMAM/pmiR-218 significantly improved the liver histological features, as well as down-regulated the HOXA1 in liver tissue. In conclusion, this study showed the potential of LA-PAMAM carrier for the targeted delivery of tumor suppressor miR-218 as a therapeutic candidate for HCC.

Biopolymer-based Carriers for DNA Vaccine Design

Over the last 30 years, genetically engineered DNA has been tested as novel vaccination strategy against various diseases, including human immunodeficiency virus (HIV), hepatitis B, several parasites, and cancers. However, the clinical breakthrough of the technique is confined by the low transfection efficacy and immunogenicity of the employed vaccines. Therefore, carrier materials were designed to prevent the rapid degradation and systemic clearance of DNA in the body. In this context, biopolymers are a particularly promising DNA vaccine carrier platform due to their beneficial biochemical and physical characteristics, including biocompatibility, stability, and low toxicity. This article reviews the applications, fabrication, and modification of biopolymers as carrier medium for genetic vaccines.

The Role of Formamidine Groups in Dextran Based Nonviral Vectors for Gene Delivery on Their Physicochemical and Biological Characteristics

Dextran-formamidine esters (dextran-N-[(dimethylamino)methylene]-β-alanine ester) with different degrees of substitution (0.45-0.92) are synthesized in an one-pot reaction. Dextran (Mw 60 000 g mol^-1 ) is allowed to react with unprotected beta-alanine and iminium chloride and investigated regarding the potential as gene delivery system for the transfer of plasmid DNA. With degrees of substitution ≥ 0.63 improved DNA binding with formation of enzymatically stable complexes of about 130-160 nm with negative surface charges are obtained. These physicochemical characteristics correlated with increasing transfection rates in CHO-K1 cells determined by a luciferase reporter gene assay in dependency of the number of formamidine residues, N/P ratios and amount of DNA. The role of the number of formamidine groups is also highlighted by in vitro cyto- and hemotoxicity tests under the chosen conditions. These results indicate that dextran-formamidine esters are a very promising material for the safe and efficient gene delivery.

Extending the application of a magnetic PEG three-part drug release device on a graphene substrate for the removal of Gram-positive and Gram-negative bacteria and cancerous and pathologic cells

Objective

In this study, novel graphene oxide (GO)-based nanocomposites are presented. In fact, we have tried to replace the carboxyl groups on the surface of GO with amine groups to allow the biocompatible poly(ethylene glycol) bis(carboxymethyl) ether (average Mn 600) polymer to bond through an amide bond.

Materials and methods

The synthesis was conducted accurately according to final characterization experiments (Raman, X-ray diffraction [XRD], atomic force microscopy [AFM], X-ray photoelectron spectroscopy [XPS], thermogravimetric analysis [TGA], etc). The antimicrobial property of this nanocomposite was examined in Escherichia coli (ATCC 25922) as Gram-negative and Staphylococcus aureus (ATCC 25923) as Gram-positive bacterial species. Besides, curcumin (CUR) was added to the produced nanocomposite both as a promising anticancer drug and an antioxidant, the toxicity of which was then assessed on cellular-based HepG2 and pC12.

Results

An intense increase in toxicity was detected by MTT assay.

Conclusion

It can mainly be concluded that the nanocomposite synthesized in this study is capable of delivering drugs with antibacterial properties.

Overviews on the cellular uptake mechanism of polysaccharide colloidal nanoparticles

Nanoparticulate drug/gene carriers have gained much attention in the past decades because of their versatile and tunable properties. However, efficacy of the therapeutic agents can be further enhanced using naturally occurring materials-based nanoparticles. Polysaccharides are an emerging class of biopolymers; therefore, they are generally considered to be safe, non-toxic, biocompatible and biodegradable. Considering that the target of nanoparticle-based therapeutic strategies is localization of biomedical agents in subcellular compartments, a detailed understanding of the cellular mechanism involved in the uptake of polysaccharide-based nanoparticles is essential for safe and efficient therapeutic applications. Uptake of the nanoparticles by the cellular systems occurs with a process known as endocytosis and is influenced by the physicochemical characteristics of nanoparticles such as size, shape and surface chemistry as well as the employed experimental conditions. In this study, we highlight the main endocytosis mechanisms responsible for the cellular uptake of polysaccharide nanoparticles containing drug/gene.

In-Vitro Assessment of Magnetic Dextran-Spermine Nanoparticles for Capecitabine Delivery to Cancerous Cells

Cationic polymeric nanoparticles have great potential for developing drug delivery systems with limited side effects for tumor medication. The goal of this research is investigation of cationic dextran-spermine polymer (DS) efficacy for improvement of hydrophilic drug delivery to negatively charged cancerous cells. Capecitabine (as a hydrophilic antineoplastic drug) was loaded into the magnetic dextran-spermine nanoparticles (DS-NPs) via ionic gelation. Design of experiments was applied to specify how the significant factors affect size, surface charge and capecitabine entrapment efficiency of the DS-NPs. Physicochemical properties, in-vitro release profile and cellular studies of the optimized DS-NPs were evaluated. The experimental results indicated that DS-NPs with favorable properties can be achieved at an optimized condition of 2 mg/mL DS and 0.75 mg/mL tri-polyphosphate (TPP) concentrations, TPP addition rate of 35 mL/min, pH 3 of DS solution and super paramagnetic iron oxide nanoparticles (SPION)/DS mass ratio of 0.5. The entrapment efficiency of capecitabine was 26.1% at optimum condition and drug release at neutral pH after 24 h and acidic pH within 3 h was 56 and 98%, respectively. The cytotoxicity assessment exhibited that capecitabine loaded DS-NPs was more toxic than corresponding free drug as control. Significant cellular uptake of capecitabine loaded DS-NPs by U87MG glioblastoma cells were proved by Prussian blue staining and TEM, qualitatively. DS-NPs are suitable candidates for delivery of the hydrophilic drugs in cancer treatment and due to positive charge of the dextran-spermine, the uptake of the hydrophilic drugs by the cancerous cells was improved.

In vivo fate tracking of degradable nanoparticles for lung gene transfer using PET and Ĉerenkov imaging

Nanoparticles (NPs) play expanding roles in biomedical applications including imaging and therapy, however, their long-term fate and clearance profiles have yet to be fully characterized in vivo. NP delivery via the airway is particularly challenging, as the clearance may be inefficient and lung immune responses complex. Thus, specific material design is required for cargo delivery and quantitative, noninvasive methods are needed to characterize NP pharmacokinetics. Here, biocompatible poly(acrylamidoethylamine)-b-poly(dl-lactide) block copolymer-based degradable, cationic, shell-cross-linked knedel-like NPs (Dg-cSCKs) were employed to transfect plasmid DNA. Radioactive and optical beacons were attached to monitor biodistribution and imaging. The preferential release of cargo in acidic conditions provided enhanced transfection efficiency compared to non-degradable counterparts. In vivo gene transfer to the lung was correlated with NP pharmacokinetics by radiolabeling Dg-cSCKs and performing quantitative biodistribution with parallel positron emission tomography and Čerenkov imaging. Quantitation of imaging over 14 days corresponded with the pharmacokinetics of NP movement from the lung to gastrointestinal and renal routes, consistent with predicted degradation and excretion. This ability to noninvasively and accurately track NP fate highlights the advantage of incorporating multifunctionality into particle design.

Nanoparticle-based technologies for retinal gene therapy

For patients with hereditary retinal diseases, retinal gene therapy offers significant promise for the prevention of retinal degeneration. While adeno-associated virus (AAV)-based systems remain the most popular gene delivery method due to their high efficiency and successful clinical results, other delivery systems, such as non-viral nanoparticles (NPs) are being developed as additional therapeutic options. NP technologies come in several categories (e.g., polymer, liposomes, peptide compacted DNA), several of which have been tested in mouse models of retinal disease. Here, we discuss the key biochemical features of the different NPs that influence how they are internalized into cells, escape from endosomes, and are delivered into the nucleus. We review the primary mechanism of NP uptake by retinal cells and highlight various NPs that have been successfully used for in vivo gene delivery to the retina and RPE. Finally, we consider the various strategies that can be implemented in the plasmid DNA to generate persistent, high levels of gene expression.

Cationic Polysaccharides in Gene Delivery

Approval of Glybera®, a gene therapy to treat lipoprotein lipase deficiency, by the European Union Marketing Authorization, and more than 1800 clinical trials in over 31 countries for the treatment of many incurable diseases, narrates the successful journey of gene therapy in the biomedical field. However, the undesired side effects of gene therapy using viral and other vectors have overshadowed the success story of gene therapy. Non-viral vectors, and more particularly cationic polysaccharides due to their non-toxicity, water solubility, biodegradability and excellent compatibility with body systems, provide an excellent alternative for gene delivery. This chapter highlights significant contributions made by cationic polysaccharides in gene delivery.

Star-shaped tetraspermine enhances cellular uptake and cytotoxicity of T-oligo in prostate cancer cells

PURPOSE

An oligonucleotide termed 'T-oligo' having sequence homology with telomere overhang has shown cytotoxicity in multiple cancers. We have demonstrated that T-oligo can induce apoptosis in androgen independent prostate cancer cell line DU-145. In this report, we evaluate the use of star-shaped tetraspermine (SSTS) for delivery of T-oligo.

METHODS

SSTS was synthesized from spermine and its intrinsic cytotoxicity towards DU-145 cells was compared with spermine and branched polyethyleneimine (bPEI). Atomistic molecular dynamic (MD) simulations were conducted to understand binding and complexation of spermine and SSTS with T-oligo. Complexation was also determined using gel electrophoresis and SYBR gold assay. Complexes were characterized for size, cellular uptake and antiproliferative effect.

RESULTS

SSTS exhibited significantly lower toxicity than spermine and bPEI. Its affinity towards T-oligo was significantly higher than spermine as determined by experimental studies and confirmed by MD simulations and it formed stable complexes (TONPs) with T-oligo. TONPs facilitated cellular uptake and nuclear accumulation of T-oligo and their cytotoxic potential was observed at concentration several folds lower than that required for T-oligo alone.

CONCLUSION

SSTS significantly enhanced therapeutic benefits associated with the use of T-oligo and can be developed as a delivery vehicle for its in-vivo therapeutic applications.

Gene delivery potential of biofunctional carbonate apatite nanoparticles in lungs

Existing nonviral gene delivery systems to lungs are inefficient and associated with dose limiting toxicity in mammalian cells. Therefore, carbonate apatite (CO₃Ap) nanoparticles were examined as an alternative strategy for effective gene delivery to the lungs. This study aimed to (1) assess the gene delivery efficiency of CO₃Ap in vitro and in mouse lungs, (2) evaluate the cytotoxicity effect of CO₃Ap/pDNA in vitro, and (3) characterize the CO₃Ap/pDNA complex formulations. A significantly high level of reporter gene expression was detected from the lung cell line transfected with CO₃Ap/pDNA complex prepared in both serum and serum-free medium. Cytotoxicity analysis revealed that the percentage of the viable cells treated with CO₃Ap to be almost similar to the untreated cells. Characterization analyses showed that the CO₃Ap/pDNA complexes are in a nanometer range with aggregated spherical structures and tended to be more negatively charged. In the lung of mice, highest level of transgene expression was observed when CO₃Ap (8 μL) was complexed with 40 μg of pDNA at day 1 after administration. Although massive reduction of gene expression was seen beyond day 1 post administration, the level of expression remained significant throughout the study period.

Polysaccharide gene transfection agents

Gene delivery is a promising technique that involves in vitro or in vivo introduction of exogenous genes into cells for experimental and therapeutic purposes. Successful gene delivery depends on the development of effective and safe delivery vectors. Two main delivery systems, viral and non-viral gene carriers, are currently deployed for gene therapy. While most current gene therapy clinical trials are based on viral approaches, non-viral gene medicines have also emerged as potentially safe and effective for the treatment of a wide variety of genetic and acquired diseases. Non-viral technologies consist of plasmid-based expression systems containing a gene associated with the synthetic gene delivery vector. Polysaccharides compile a large family of heterogenic sequences of monomers with various applications and several advantages as gene delivery agents. This chapter, compiles the recent progress in polysaccharide based gene delivery, it also provides an overview and recent developments of polysaccharide employed for in vitro and in vivo delivery of therapeutically important nucleotides, e.g. plasmid DNA and small interfering RNA.

Development of 3D in vitro platform technology to engineer mesenchymal stem cells

This study aims to develop a three-dimensional in vitro culture system to genetically engineer mesenchymal stem cells (MSC) to express bone morphogenic protein-2. We employed nanofabrication technologies borrowed from the spinning industry, such as electrospinning, to mass-produce identical building blocks in a variety of shapes and sizes to fabricate electrospun nanofiber sheets comprised of composites of poly (glycolic acid) and collagen. Homogenous nanoparticles of cationic biodegradable natural polymer were formed by simple mixing of an aqueous solution of plasmid DNA encoded bone morphogenic protein-2 with the same volume of cationic polysaccharide, dextran-spermine. Rat bone marrow MSC were cultured on electrospun nanofiber sheets comprised of composites of poly (glycolic acid) and collagen prior to the incorporation of the nanoparticles into the nanofiber sheets. Bone morphogenic protein-2 was significantly detected in MSC cultured on nanofiber sheets incorporated with nanoparticles after 2 days compared with MSC cultured on nanofiber sheets incorporated with naked plasmid DNA. We conclude that the incorporation of nanoparticles into nanofiber sheets is a very promising strategy to genetically engineer MSC and can be used for further applications in regenerative medicine therapy.

Nanoparticle-based monitoring of cell therapy

Exogenous cell therapy aims to replace/repair diseased or dysfunctional cells and promises to revolutionize medicine by restoring tissue and organ function. To develop effective cell therapy, the location, distribution and long-term persistence of transplanted cells must be evaluated. Nanoparticle (NP) based imaging technologies have the potential to track transplanted cells non-invasively. Here we summarize the most recent advances in NP-based cell tracking with emphasis on (1) the design criteria for cell tracking NPs, (2) protocols for cell labeling, (3) a comparison of available imaging modalities and their corresponding contrast agents, (4) a summary of preclinical studies on NP-based cell tracking and finally (5) perspectives and future directions.