Hybrid superparamagnetic iron oxide nanoparticle-branched polyethylenimine magnetoplexes for gene transfection of vascular endothelial cells

Advances in superparamagnetic iron oxide nanoparticles modified with branched polyethyleneimine for multimodal imaging

Multimodal imaging are approaches which combines multiple imaging techniques to obtain multi-aspect information of a target through different imaging modalities, thereby greatly improve the accuracy and comprehensiveness of imaging. Superparamagnetic iron oxide nanoparticles (SPIONs) modified with branched polyethyleneimine have revealed good biocompatibility and stability, high drug loading capacity and nucleic acid transfection efficiency. SPIONs have been developed as functionalized platforms which can be further modified to enhance their functionalities. Those further modifications facilitate the application of SPIONs in multimodal imaging. In this review, we discuss the methods, advantages, applications, and prospects of BPEI-modified SPIONs in multimodal imaging.

Magnetically-assisted viral transduction (magnetofection) medical applications: An update

Gene therapy involves replacing a faulty gene or adding a new gene inside the body's cells to cure disease or improve the body's ability to fight disease. Its popularity is evident from emerging concepts such as CRISPR-based genome editing and epigenetic studies and has been moved to a clinical setting. The strategy for therapeutic gene design includes; suppressing the expression of pathogenic genes, enhancing necessary protein production, and stimulating the immune system, which can be incorporated into both viral and non-viral gene vectors. Although non-viral gene delivery provides a safer platform, it suffers from an inefficient rate of gene transfection, which means a few genes could be successfully transfected and expressed within the cells. Incorporating nucleic acids into the viruses and using these viral vectors to infect cells increases gene transfection efficiency. Consequently, more cells will respond, more genes will be expressed, and sustained and successful gene therapy can be achieved. Combining nanoparticles (NPs) and nucleic acids protects genetic materials from enzymatic degradation. Furthermore, the vectors can be transferred faster, facilitating cell attachment and cellular uptake. Magnetically assisted viral transduction (magnetofection) enhances gene therapy efficiency by mixing magnetic nanoparticles (MNPs) with gene vectors and exerting a magnetic field to guide a significant number of vectors directly onto the cells. This research critically reviews the MNPs and the physiochemical properties needed to assemble an appropriate magnetic viral vector, discussing cellular hurdles and attitudes toward overcoming these barriers to reach clinical gene therapy perspectives. We focus on the studies conducted on the various applications of magnetic viral vectors in cancer therapies, regenerative medicine, tissue engineering, cell sorting, and virus isolation.

A Detailed Review on Synthesis, Functionalization, Application, Challenges, and Current Status of Magnetic Nanoparticles in the Field of Drug Delivery and Gene Delivery System

For progression of health care system, it has always been a challenge to the researchers for formulation to a type of advanced drug delivery system which will have less toxicity, targeted delivery and will be highly biodegradable. Nano science or nanotechnology has been validated to be a successful method as of targeting the drug to its active site be due to its special physicochemical properties and size thereby reducing the dose of administration, increasing bioavailability, and also reducing toxicity. Magnetic nanoparticles recently in few decades have proved as an effective advanced drug delivery system for its elevated magnetic responsiveness, biocompatibility, elevated targeted drug delivery effectiveness, etc. The drug can be easily targeted to active site by application of external magnetic field. Among the various elements, nanoparticles prepared with magnetically active iron oxide or other iron-based spinel oxide nanoparticles are widely used due to its high electrical resistivity, mechanical hardness, chemical stability, etc. Owing to their easy execution towards drug delivery application, extensive research has been carried out in this area. This review paper has summarized all recent modifications of iron-based magnetically active nanoparticle based drug delivery system along with their synthesis, characterization, and applications.

Overcoming the non-kinetic activity of EGFR1 using multi-functionalized mesoporous silica nanocarrier for in vitro delivery of siRNA

Triple-negative breast cancer (TNBC) does not respond to HER2-targeted and hormone-based medicines. Epidermal growth factor receptor 1 (EGFR1) is commonly overexpressed in up to 70% of TNBC cases, so targeting cancer cells via this receptor could emerge as a favored modality for TNBC therapy due to its target specificity. The development of mesoporous silica nanoparticles (MSNs) as carriers for siRNAs remains a rapidly growing area of research. For this purpose, a multi-functionalized KIT-6 containing the guanidinium ionic liquid (GuIL), PEI and PEGylated folic acid (FA-PEG) was designed. Accordingly, KIT-6 was fabricated and modified with FA-PEG and PEI polymers attached on the surface and the GuIL placed in the mesopores. Subsequent to confirming the structure of this multi-functionalized KIT-6- based nanocarrier using TEM, SEM, AFM, BET, BJH, DLS and Zeta Potential, it was investigated for uploading and transferring the anti-EGFR1 siRNAs to the MD-MBA-231 cell line. The rate of cellular uptake, cellular localization and endolysosomal escape was evaluated based on the fluorescent intensity of FAM-labelled siRNA using flowcytometry analysis and confocal laser scanning microscopy (CLSM). The 64% cellular uptake after 4 h incubation, clearly suggested the successful delivery of siRNA into the cells and, CLSM demonstrated that siRNA@[FA-PEGylated/PEI@GuIL@KIT-6] may escape endosomal entrapment after 6 h incubation. Using qPCR, quantitative evaluation of EGFR1 gene expression, a knockdown of 82% was found, which resulted in a functional change in the expression of EGFR1 targets. Co-treatment of chemotherapy drug "carboplatin" in combination with siRNA@[FA-PEGylated/PEI@GuIL@KIT-6] exhibited a remarkable cytotoxic effect in comparison to carboplatin alone.

Estimating the two graph dextran-stearic acid-spermine polymers based on iron oxide nanoparticles as carrier for gene delivery

Non-viral gene carriers have shown noticeable potential in gene delivery because of limited side effects, biocompatibility, simplicity, and the ability to take advantage of electrostatic interactions. However, the low transfection rate of non-viral vectors under physiological conditions is controversial. This study aimed to decrease the transfection time using a static magnetic field. We used self-assembled cationic polysaccharides based on dextran-stearic acid-spermine (DSASP) conjugates associated with Fe₃ O₄ superparamagnetic nanoparticles to investigate their potential as gene carriers to promote the target delivery. Our findings illustrate that the magnetic nanoparticles are spherical with a positive surface charge and exhibit superparamagnetic behavior. The DSASP-pDNA/Fe₃ O₄ complexes offered a strong pDNA condensation, protection against DNase degradation, and significant cell viability in HEK 293T cells. Our results demonstrated that although conjugation of stearic acid could play a role in transfection efficiency, DSASP magnetic carriers with more spermine derivatives showed better affinity between the amphiphilic polymer and the negatively charged cell membrane.

Chitosan-Crosslinked Low Molecular Weight PEI-Conjugated Iron Oxide Nanoparticle for Safe and Effective DNA Delivery to Breast Cancer Cells

Breast cancer has attracted tremendous research interest in treatment development as one of the major threats to public health. The use of non-viral carriers for therapeutic DNA delivery has shown promise in treating various cancer types, including breast cancer, due to their high DNA loading capacity, high cell transfection efficiency, and design versatility. However, cytotoxicity and large sizes of non-viral DNA carriers often raise safety concerns and hinder their applications in the clinic. Here we report the development of a novel nanoparticle formulation (termed NP-Chi-xPEI) that can safely and effectively deliver DNA into breast cancer cells for successful transfection. The nanoparticle is composed of an iron oxide core coated with low molecular weight (800 Da) polyethyleneimine crosslinked with chitosan via biodegradable disulfide bonds. The NP-Chi-xPEI can condense DNA into a small nanoparticle with the overall size of less than 100 nm and offer full DNA protection. Its biodegradable coating of small-molecular weight xPEI and mildly positive surface charge confer extra biocompatibility. NP-Chi-xPEI-mediated DNA delivery was shown to achieve high transfection efficiency across multiple breast cancer cell lines with significantly lower cytotoxicity as compared to the commercial transfection agent Lipofectamine 3000. With demonstrated favorable physicochemical properties and functionality, NP-Chi-xPEI may serve as a reliable vehicle to deliver DNA to breast cancer cells.

Uniform iron oxide nanoparticles reduce the required amount of polyethylenimine in the gene delivery to mesenchymal stem cells

Cationic polyethylenimine (PEI) is regarded as the 'golden standard' of non-viral gene vectors. However, the superiority of PEI with high positive charge density also induces its major drawback of cytotoxicity, which restricts its application for an effective and safe gene delivery to stem cells. To redress this shortcoming, herein, a magnetic gene complex containing uniform iron oxide nanoparticles (UIONPs), plasmid DNA, and free PEI is prepared through electrostatic interactions for the gene delivery to bone marrow-derived mesenchymal stem cells (BM-MSCs). Results show that UIONPs dramatically promote the gene delivery to BM-MSCs using the assistance of magnetic force. In addition, decreasing the free PEI nitrogen to DNA phosphate (N/P) ratio from 10 to 6 has little adverse impact on the transgene expression levels (over 300 times than that of PEI alone at the N/P ratio of 6) and significantly reduces the cytotoxicity to BM-MSCs. Further investigations confirmed that the decrease of free PEI has little influence on the cellular uptake after applying external magnetic forces, but that the reduced positive charge density decreases the cytotoxicity. The present study demonstrates that magnetic gene delivery not only contributes to the enhanced gene expression but also helps to reduce the required amount of PEI, providing a potential strategy for an efficient and safe gene delivery to stem cells.

Klotho and Mesenchymal Stem Cells: A Review on Cell and Gene Therapy for Chronic Kidney Disease and Acute Kidney Disease

Chronic kidney disease (CKD) and acute kidney injury (AKI) are public health problems, and their prevalence rates have increased with the aging of the population. They are associated with the presence of comorbidities, in particular diabetes mellitus and hypertension, resulting in a high financial burden for the health system. Studies have indicated Klotho as a promising therapeutic approach for these conditions. Klotho reduces inflammation, oxidative stress and fibrosis and counter-regulates the renin-angiotensin-aldosterone system. In CKD and AKI, Klotho expression is downregulated from early stages and correlates with disease progression. Therefore, the restoration of its levels, through exogenous or endogenous pathways, has renoprotective effects. An important strategy for administering Klotho is through mesenchymal stem cells (MSCs). In summary, this review comprises in vitro and in vivo studies on the therapeutic potential of Klotho for the treatment of CKD and AKI through the administration of MSCs.

Supramolecular Surface Functionalization of Iron Oxide Nanoparticles with α-Cyclodextrin-Based Cationic Star Polymer for Magnetically-Enhanced Gene Delivery

Supramolecular polymers formed through host-guest complexation have inspired many interesting developments of functional materials for biological and biomedical applications. Here, we report a novel design of a non-viral gene delivery system composed of a cationic star polymer forming supramolecular complexes with the surface oleyl groups of superparamagnetic iron oxide nanoparticles (SPIONs), for magnetically enhanced delivery of DNA into mammalian cells. The cationic star polymer was synthesized by grafting multiple oligoethylenimine (OEI) chains onto an α-cyclodextrin (α-CD) core. The SPIONs were synthesized from iron(III) acetylacetonate and stabilized by hydrophobic oleic acid and oleylamine in hexane, which were characterized in terms of their size, structure, morphology, and magnetic properties. The synthesized magnetic particles were found to be superparamagnetic, making them a suitable ferrofluid for biological applications. In order to change the hydrophobic surface of the SPIONs to a hydrophilic surface with functionalities for plasmid DNA (pDNA) binding and gene delivery, a non-traditional but simple supramolecular surface modification process was used. The α-CD-OEI cationic star polymer was dissolved in water and then mixed with the SPIONs stabilized in hexane. The SPIONs were "pulled" into the water phase through the formation of supramolecular host-guest inclusion complexes between the α-CD unit and the oleyl surface of the SPIONs, while the surface of the SPIONs was changed to OEI cationic polymers. The α-CD-OEI-SPION complex could effectively bind and condense pDNA to form α-CD-OEI-SPION/pDNA polyplex nanoparticles at the size of ca. 200 nm suitable for delivery of genes into cells through endocytosis. The cytotoxicity of the α-CD-OEI-SPION complex was also found to be lower than high-molecular-weight polyethylenimine, which was widely studied previously as a standard non-viral gene vector. When gene transfection was carried out in the presence of an external magnetic field, the α-CD-OEI-SPION/pDNA polyplex nanoparticles greatly increased the gene transfection efficiency by nearly tenfold. Therefore, the study has demonstrated a facile two-in-one method to make the SPIONs water-soluble as well as functionalized for enhanced magnetofection.

Magnetic transfection with superparamagnetic chitosan-loaded IGFBP5 nanoparticles and their in vitro biosafety

We prepared the superparamagnetic chitosan nanoparticles (SPCIONPs) to study the application of them as gene vectors using a magnetic transfection system for the targeted treatment of lung metastasis of osteosarcoma. The SPCIONPs were characterized by transmission electron microscopy, Fourier transform infrared spectrometry, superconducting quantum interference device and atomic force microscopy. Their biosafety was determined by cell counting kit-8 (CCK8) and live-dead staining assays. The transfection in vitro was detected by laser confocal microscopy. SPCIONPs, which can bind closely to plasmids and protect them from DNA enzyme degradation, were prepared with an average particle size of approximately 22 nm and zeta potential of 11.3 mV. The results of the CCK8 and live-dead staining assays showed that superparamagnetic chitosan nanoparticles loaded with insulin-like growth factor-binding protein 5 (SPCIONPs/pIGFBP5) induced no significant cytotoxicity compared to the control group. The result of transfection in vitro suggested that pIGFBP5 emitted a greater amount of red fluorescence in the SPCIONPs/pIGFBP5 group than that in the chitosan-loaded IGFBP5 (CS/pIGFBP5) group. In conclusion, the prepared SPCIONPs had good biosafety and could be effectively used to transfer pIGFBP5 into 143B cells, and they thus have good application prospects for the treatment of lung metastasis of osteosarcoma.

Mesenchymal Stem Cell Therapy for Diabetic Kidney Disease: A Review of the Studies Using Syngeneic, Autologous, Allogeneic, and Xenogeneic Cells

Diabetic kidney disease (DKD) is a microvascular complication of diabetes mellitus (DM) and comprises multifactorial pathophysiologic mechanisms. Despite current treatment, around 30-40% of individuals with type 1 and type 2 DM (DM1 and DM2) have progressive DKD, which is the most common cause of end-stage chronic kidney disease worldwide. Mesenchymal stem cell- (MSC-) based therapy has important biological and therapeutic implications for curtailing DKD progression. As a chronic disease, DM may impair MSC microenvironment, but there is compelling evidence that MSC derived from DM1 individuals maintain their cardinal properties, such as potency, secretion of trophic factors, and modulation of immune cells, so that both autologous and allogeneic MSCs are safe and effective. Conversely, MSCs derived from DM2 individuals are usually dysfunctional, exhibiting higher rates of senescence and apoptosis and a decrease in clonogenicity, proliferation, and angiogenesis potential. Therefore, more studies in humans are needed to reach a conclusion if autologous MSCs from DM2 individuals are effective for treatment of DM-related complications. Importantly, the bench to bedside pathway has been constructed in the last decade for assessing the therapeutic potential of MSCs in the DM setting. Laboratory research set the basis for establishing further translation research including preclinical development and proof of concept in model systems. Phase I clinical trials have evaluated the safety profile of MSC-based therapy in humans, and phase II clinical trials (proof of concept in trial participants) still need to answer important questions for treating DKD, yet metabolic control has already been documented. Therefore, randomized and controlled trials considering the source, optimal cell number, and route of delivery in DM patients are further required to advance MSC-based therapy. Future directions include strategies to reduce MSC heterogeneity, standardized protocols for isolation and expansion of those cells, and the development of well-designed large-scale trials to show significant efficacy during a long follow-up, mainly in individuals with DKD.

Small interfering RNAs (siRNAs) based gene silencing strategies for the treatment of glaucoma: Recent advancements and future perspectives

RNA-interference-based mechanisms, especially the use of small interfering RNAs (siRNAs), have been under investigation for the treatment of several ailments and have shown promising results for ocular diseases including glaucoma. The eye, being a confined compartment, serves as a good target for the delivery of siRNAs. This review focuses on siRNA-based strategies for gene silencing to treat glaucoma. We have discussed the ocular structures and barriers to gene therapy (tear film, corneal, conjunctival, vitreous, and blood ocular barriers), methods of administration for ocular gene delivery (topical instillation, periocular, intracameral, intravitreal, subretinal, and suprachoroidal routes) and various viral and non-viral vectors in siRNA-based therapy for glaucoma. The components and mechanism of siRNA-based gene silencing have been mentioned briefly followed by the basic strategies and challenges faced during siRNA therapeutics development. We have emphasized different therapeutic targets for glaucoma which have been under research by scientists and the current siRNA-based drugs used in glaucoma treatment. We also mention briefly strategies for siRNA-based treatment after glaucoma surgery.

Tailoring Iron Oxide Nanoparticles for Efficient Cellular Internalization and Endosomal Escape

Iron oxide nanoparticles (IONs) have been widely explored for biomedical applications due to their high biocompatibility, surface-coating versatility, and superparamagnetic properties. Upon exposure to an external magnetic field, IONs can be precisely directed to a region of interest and serve as exceptional delivery vehicles and cellular markers. However, the design of nanocarriers that achieve an efficient endocytic uptake, escape lysosomal degradation, and perform precise intracellular functions is still a challenge for their application in translational medicine. This review highlights several aspects that mediate the activation of the endosomal pathways, as well as the different properties that govern endosomal escape and nuclear transfection of magnetic IONs. In particular, we review a variety of ION surface modification alternatives that have emerged for facilitating their endocytic uptake and their timely escape from endosomes, with special emphasis on how these can be manipulated for the rational design of cell-penetrating vehicles. Moreover, additional modifications for enhancing nuclear transfection are also included in the design of therapeutic vehicles that must overcome this barrier. Understanding these mechanisms opens new perspectives in the strategic development of vehicles for cell tracking, cell imaging and the targeted intracellular delivery of drugs and gene therapy sequences and vectors.

New Insights into Biocompatible Iron Oxide Nanoparticles: A Potential Booster of Gene Delivery to Stem Cells

Gene delivery to stem cells is a critical issue of stem cells-based therapies, still facing ongoing challenges regarding efficiency and safety. Recent advances in the controlled synthesis of biocompatible magnetic iron oxide nanoparticles (IONPs) have provided a powerful nanotool for assisting gene delivery to stem cells. However, this field is still at an early stage, with well-designed and scalable IONPs synthesis highly desired. Furthermore, the potential risks or bioeffects of IONPs on stem cells are not completely figured out. Therefore, in this review, the updated researches focused on the gene delivery to stem cells using various designed IONPs are highlighted. Additionally, the impacts of the physicochemical properties of IONPs, as well as the magnetofection systems on the gene delivery performance and biocompatibility are summarized. Finally, challenges attributed to the potential impacts of IONPs on the biologic behaviors of stem cells and the large-scale productions of uniform IONPs are emphasized. The principles and challenges summarized in this review provide a general guidance for the rational design of IONPs-assisted gene delivery to stem cells.

Polyethylenimine based magnetic nanoparticles mediated non-viral CRISPR/Cas9 system for genome editing

Clustered regularly interspaced short palindromic repeats-associated protein (CRISPR/Cas9) system has become a revolutionary tool for gene editing. Since viral delivery systems have significant side effects, and naked DNA delivery is not an option, the nontoxic, non-viral delivery of CRISPR/Cas9 components would significantly improve future therapeutic delivery. In this study, we aim at characterizing nanoparticles to deliver plasmid DNA encoding for the CRISPR-Cas system in eukaryotic cells in vitro. CRISPR/Cas9 complexed polyethylenimine (PEI) magnetic nanoparticles (MNPs) were generated. We used a stable HEK293 cell line expressing the traffic light reporter (TLR-3) system to evaluate efficient homology- directed repair (HDR) and non-homologous end joining (NHEJ) events following transfection with NPs. MNPs have been synthesized by co-precipitation with the average particle size around 20 nm in diameter. The dynamic light scattering and zeta potential measurements showed that NPs exhibited narrow size distribution and sufficient colloidal stability. Genome editing events were as efficient as compared to standard lipofectamine transfection. Our approach tested non-viral delivery of CRISPR/Cas9 and DNA template to perform HDR and NHEJ in the same assay. We demonstrated that PEI-MNPs is a promising delivery system for plasmids encoding CRISPR/Cas9 and template DNA and thus can improve safety and utility of gene editing.

Flexible Ferrofluids: Design and Applications

Ferrofluids, also known as ferromagnetic particle suspensions, are materials with an excellent magnetic response, which have attracted increasing interest in both industrial production and scientific research areas. Because of their outstanding features, such as rapid magnetic reaction, flexible flowability, as well as tunable optical and thermal properties, ferrofluids have found applications in various fields, including material science, physics, chemistry, biology, medicine, and engineering. Here, a comprehensive, in-depth insight into the diverse applications of ferrofluids from material fabrication, droplet manipulation, and biomedicine to energy and machinery is provided. Design of ferrofluid-related devices, recent developments, as well as present challenges and future prospects are also outlined.

Improving Magnetofection of Magnetic Polyethylenimine Nanoparticles into MG-63 Osteoblasts Using a Novel Uniform Magnetic Field

This study aimed to improve the magnetofection of MG-63 osteoblasts by integrating the use of a novel uniform magnetic field with low molecular weight polyethylenimine modified superparamagnetic iron oxide nanoparticles (PEI-SPIO-NPs). The excellent characteristics of PEI-SPIO-NPs such as size, zeta potential, the pDNA binding and protective ability were determined to be suitable for gene delivery. The novel uniform magnetic field enabled polyethylenimine-modified superparamagnetic iron oxide nanoparticles/pDNA complexes (PEI-SPIO-NPs/pDNA complexes) to rapidly and uniformly distribute on the surface of MG-63 cells, averting local transfection and decreasing disruption of the membrane caused by the centralization of positively charged PEI-SPIO-NPs, thereby increasing the effective coverage of magnetic gene carriers during transfection, and improving magnetofection efficiency. This innovative uniform magnetic field can be used to determine the optimal amount between PEI-SPIO-NPs and pDNA, as well as screen for the optimal formulation design of magnetic gene carrier under the homogenous conditions. Most importantly, the novel uniform magnetic field facilitates the transfection of PEI-SPIO-NPs/pDNA into osteoblasts, thereby providing a novel approach for the targeted delivery of therapeutic genes to osteosarcoma tissues as well as a reference for the treatment of other tumors.

A Critical Review on Selected External Physical Cues and Modulation of Cell Behavior: Magnetic Nanoparticles, Non-thermal Plasma and Lasers

Physics-based biomedical approaches have proved their importance for the advancement of medical sciences and especially in medical diagnostics and treatments. Thus, the expectations regarding development of novel promising physics-based technologies and tools are very high. This review describes the latest research advances in biomedical applications of external physical cues. We overview three distinct topics: using high-gradient magnetic fields in nanoparticle-mediated cell responses; non-thermal plasma as a novel bactericidal agent; highlights in understanding of cellular mechanisms of laser irradiation. Furthermore, we summarize the progress, challenges and opportunities in those directions. We also discuss some of the fundamental physical principles involved in the application of each cue. Considerable technological success has been achieved in those fields. However, for the successful clinical translation we have to understand the limitations of technologies. Importantly, we identify the misconceptions pervasive in the discussed fields.

Remarkable Amplification of Polyethylenimine-Mediated Gene Delivery Using Cationic Poly(phenylene ethynylene)s as Photosensitizers

Conjugated polymers can serve as good photosensitizers in biomedical applications. However, it remains unknown whether they are phototoxic to the supercoiled structure of DNA in improving gene delivery by the photochemical internalization (PCI) strategy, which complicates the application of conjugated polymers in gene delivery. In this work, we introduced a trace amount of cationic poly(phenylene ethynylene)s (cPPEs) into the polymeric shell of branched polyethylenimine (BPEI)/DNA complexes, studied the photosensitization of singlet oxygen by cPPEs, and confirmed that the supercoiled DNA is undamaged by the singlet oxygen generated by the photoexcitation of cPPEs. By taking advantage of the cPPE-mediated PCI effect, we report that the addition of the trace amount of cPPEs to the outer shell of the BPEI/DNA polyplexes could greatly amplify the transfection of gene green fluorescent protein on tumor cells with the efficiency from 14 to 86% without decreasing the cell viabilities, well solving the problem with a poor transfection capability of BPEI under low DNA-loading conditions. Our strategy to employ conjugated polymers as photosensitizing agents in gene delivery systems is simple, safe, efficient, and promising for broad applications in gene delivery areas.

Non-viral Gene Delivery

Although viral vectors comprise the majority of gene delivery vectors, their various safety, production, and other practical concerns have left a research gap to be addressed. The non-viral vector space encompasses a growing variety of physical and chemical methods capable of gene delivery into the nuclei of target cells. Major physical methods described in this chapter are microinjection, electroporation, and ballistic injection, magnetofection, sonoporation, optical transfection, and localized hyperthermia. Major chemical methods described in this chapter are lipofection, polyfection, gold complexation, and carbon-based methods. Combination approaches to improve transfection efficiency or reduce immunological response have shown great promise in expanding the scope of non-viral gene delivery.

Systematic magnetic fluid hyperthermia studies of carboxyl functionalized hydrophilic superparamagnetic iron oxide nanoparticles based ferrofluids

We have systematically studied heating efficiencies (via specific absorption rate-SAR/intrinsic loss power-ILP) of carboxyl (terephthalic acid-TA) functionalized hydrophilic SPIONs based ferrofluids (with good biocompatibility/high magnetization) and influence of following key factors in magnetic fluid hyperthermia (MFH): (i) alternating magnetic fields (AMFs - H)/frequencies (f) - chosen below/above Hergt's biological safety limit, (ii) concentrations (0.5-8 mg/ml) and (iii) dispersion media (water, a cell-culture medium and triethylene glycol (TEG)) for in vitro cancer therapy. In calorimetric MFH, aqueous ferrofluids have displayed excellent time-dependent temperature rise for the applied AMFs, which resulted in high SAR ranging from 23.4 to 160.7 W/g_Fe, attributed to the enhanced magnetic responses via π-conjugations of short-chained TA molecules on the surface of SPIONs_. Moreover, ILP values up-to 2.5 nHm²/kg (higher than the best commercial ferrofluids) are attained for the aqueous ferrofluids when excited below the recommended safety limit. Besides, the SPIONs dispersed in high viscous TEG have exhibited the highest SAR value (178.8 W/g_Fe) and reached therapeutic temperatures at faster rates for the lowest concentration due to prominent Neel relaxations. Moreover, these SPIONs have higher killing efficiency towards MCF-7 cancer cells in in vitro studies. Thus, the TA-based ferrofluids have great potential for in vivo/clinical MFH cancer therapies.

Sequential Delivery of Doxorubicin and Zoledronic Acid to Breast Cancer Cells by CB[7]-Modified Iron Oxide Nanoparticles

Drug-loaded magnetic nanoparticles were synthesized and used for the sequential delivery of the antiresorptive agent zoledronic acid (Zol) and the cytotoxic drug doxorubicin (Dox) to breast cancer cells (MCF-7). Zol was attached to bare iron oxide nanoparticles (IONPs) via phosphonate coordination to form Z-NPs. The unbound imidazole of Zol was then used to complex the organic macrocycle CB[7] to obtain CZ-NPs. Dox was complexed to the CZ-NPs to form the fully loaded particles (DCZ-NPs), which were stable in solution at 37 °C and physiological pH (7.4). Fluorescence spectroscopy established that Dox is released in solution from DCZ-NPs suddenly (i) when the particles are subjected to magnetically induced heating to 42 °C at low pH (5.0) and (ii) in the presence of glutathione (GSH). Mass spectrometry indicated that Zol is released slowly in solution at low pH after Dox release. Magnetic measurements with a magnetic reader revealed that DCZ-NPs are internalized preferentially by MCF-7 cells versus nonmalignant cells (HEK293). Zol and Dox acted synergistically when delivered by the particles. DCZ-NPs caused a decrease in the viability of MCF-7 cells that was greater than the net decrease caused when the drugs were added to the cells individually at concentrations equivalent to those delivered by the particles. MCF-7 cells were treated with DCZ-NPs and subjected to an alternating magnetic field (AMF) which, with the nanoparticles present, raised the temperature of the cells and triggered the intracellular release of Dox, as indicated by fluorescence activated cell sorting (FACS). The cytotoxic effects of the DCZ-NPs on MCF-7 cells were enhanced 10-fold by AMF-induced heating. DCZ-NPs were also able to completely inhibit MCF-7 cell adhesion and invasion in vitro, indicating the potential of the particles to act as antimetastatic agents. Together these results demonstrate that DCZ-NPs warrant development as a system for combined chemo- and thermo-therapeutic treatment of cancer.

Influence of Physicochemical Properties and PEG Modification of Magnetic Liposomes on Their Interaction with Intestinal Epithelial Caco-2 Cells

The present study aimed to investigate the effect of particle size (100, 500 nm), surface charge (cationic, neutral and anionic) and polyethylene glycol (PEG) modification of magnetic liposomes on their interaction with the human intestinal epithelial cell line, Caco-2. The cellular associated amount of all the magnetic liposomes was significantly increased by the presence of a magnetic field. The highest association and internalization into Caco-2 cells was observed with magnetic cationic liposomes. Moreover, small magnetic liposomes were more efficiently associated and taken up into the cells, than large ones. In contrast, PEG modification significantly attenuated the enhancing effect of the magnetic field on the cellular association of magnetic liposomes. We also found that magnetic cationic liposomes had the highest retention properties to Caco-2 cells. Moreover, the retention of large magnetic liposomes to the cells was much longer than that of small ones. In addition, magnetic cationic and neutral liposomes had relatively high stability in Caco-2 cells, whereas magnetic anionic liposomes rapidly degraded. These results indicate that the physicochemical properties and PEG modification of magnetic liposomes greatly influences their intestinal epithelial transport.

Facile Synthesis of Folic Acid-Modified Iron Oxide Nanoparticles for Targeted MR Imaging in Pulmonary Tumor Xenografts

PURPOSE

The purpose of this study was to develop folic acid (FA)-modified iron oxide (Fe3O4) nanoparticles (NPs) for targeted magnetic resonance imaging (MRI) of H460 lung carcinoma cells.

PROCEDURES

Water-dispersible Fe3O4 NPs synthesized via a mild reduction method were conjugated with FA to generate FA-targeted Fe3O4 NPs. The specificity of FA-targeted Fe3O4 NPs to bind FA receptor was investigated in vitro by cellular uptake and cell MRI and in vivo by MRI of H460 tumors.

RESULTS

The formed NPs displayed good biocompatibility and ultrahigh r 2 relaxivity (440.01/mM/s). The targeting effect of the NPs to H460 cells was confirmed by in vitro cellular uptake and cell MRI. H460 tumors showed a significant reduction in T2 signal intensity at 0.85 h, which then recovered and returned to control at 2.35 h.

CONCLUSIONS

The results indicate that the prepared FA-targeted Fe3O4 NPs have potential to be used as T2 negative contrast agents in targeted MRI.

Interleukin-4 receptor-targeted delivery of Bcl-xL siRNA sensitizes tumors to chemotherapy and inhibits tumor growth

IL-4 receptor (IL-4R) is commonly up-regulated on tumor cells, and interactions between the receptor and Interleukin-4 (IL-4) can induce the expression of anti-apoptotic proteins, including Bcl-xL. This contributes to tumor cell survival and their resistance to chemotherapy. In this study, we exploited IL-4R-targeted delivery of Bcl-xL siRNA to IL-4R-expressing tumor cells in order to sensitize them to chemotherapy. To target IL-4R, an IL-4R-binding peptide, IL4RPep-1, was attached to branched polyethyleneimine-superparamagnetic iron oxide nanoparticles (BPEI-SPION). These nanoparticles were then complexed with Bcl-xL-targeting siRNA. IL-4R-targeted BPEI-SPION/Bcl-xL siRNA more efficiently reduced Bcl-xL gene expression and enhanced cytotoxicity of doxorubicin in MDA-MB231 breast tumor cells compared to untargeted BPEI-SPION/Bcl-xL siRNA. The siRNA was released from the complexes after 15 h of incubation at pH 5.5 and was stable in the complexes up to 72 h in the serum. The IL-4R-targeted BPEI-SPION/siRNA was internalized by cells through IL-4R, successfully escaped the endosomes, and was dispersed into the cytoplasm. Near-infrared fluorescence and magnetic resonance imaging demonstrated that in vivo tumor homing and accumulation of IL-4R-targeted BPEI-SPION/siRNA were both higher than untargeted BPEI-SPION/siRNA. The IL-4R-targeted BPEI-SPION/Bcl-xL siRNA, in combination with doxorubicin, significantly inhibited tumor growth in mice compared to untargeted BPEI-SPION/Bcl-xL siRNA. These results suggest that the IL-4R-targeted delivery of Bcl-xL siRNA to IL-4R-expressing tumors can sensitize tumors to chemotherapy and enhance the efficacy of anti-tumor therapeutics.

Assessment of renal function in the anaesthetised rat following injection of superparamagnetic iron oxide nanoparticles

A recent study showed that a significant fall in mean arterial pressure (MAP) occurred following intravenous injection of two novel superparamagnetic iron oxide nanoparticles (SPIONs), MF66 and OD15. To assess if this was caused by excessive glomerular clearance, the effect of both particles on renal function was studied. Experiments were performed on sodium pentobarbital anaesthetised male Wistar rats (250–350 g). Twenty-minute urine clearances were taken followed by an i.v. bolus of MF66, OD15 (2 mg·kg–1), or dH2O (0.4 mL·kg–1). MF6 or OD15 injection resulted in a significant transient drop in MAP and renal blood flow by approximately 33% and 50% (P < 0.05). The absolute excretion of sodium was significantly increased (P < 0.05) by almost 80% and 70% following OD15 and MF66, respectively. Similarly, fractional excretion of sodium was increased by almost 80% and 60% following OD15 and MF66, respectively. The glomerular filtration rate was not significantly affected, but urine flow increased nonsignificantly by approximately 50% and 66% following i.v. injection of OD15 and MF66, respectively. SPIONs produce a decrease in blood pressure and a natriuresis; however, the rate of fluid filtration in the kidney was not significantly affected.

Transferrin-decorated, MoS2-capped hollow mesoporous silica nanospheres as a self-guided chemo–photothermal nanoplatform for controlled drug release and thermotherapy

In this targeted nanoplatform, MoS₂ nanosheets act as the gatekeepers as well as photothermal agent. After NIR triggered endosomal escape, DOX can be released in the presence of intracellular GSH.

Neurotensin-Conjugated Reduced Graphene Oxide with Multi-Stage Near-Infrared-Triggered Synergic Targeted Neuron Gene Transfection In Vitro and In Vivo for Neurodegenerative Disease Therapy

Delivery efficiency with gene transfection is a pivotal point in achieving maximized therapeutic efficacy and has been an important challenge with central nervous system (CNS) diseases. In this study, neurotensin (NT, a neuro-specific peptide)-conjugated polyethylenimine (PEI)-modified reduced graphene oxide (rGO) nanoparticles with precisely controlled two-stage near-infrared (NIR)-laser photothermal treatment to enhance the ability to target neurons and achieve high gene transfection in neurons. First-stage NIR laser irradiation on the cells with nanoparticles attached on the surface can increase the permeability of the cell membrane, resulting in an apparent increase in cellular uptake compared to untreated cells. In addition, second-stage NIR laser irradiation on the cells with nanoparticles inside can further induce endo/lysosomal cavitation, which not only helps nanoparticles escape from endo/lysosomes but also prevents plasmid DNA (pDNA) from being digested by DNase I. At least double pDNA amount can be released from rGO-PEI-NT/pDNA under NIR laser trigger release compared to natural release. Moreover, in vitro differentiated PC-12 cell and in vivo mice (C57BL/6) brain transfection experiments have demonstrated the highest transfection efficiency occurring when NT modification is combined with external multi-stage stimuli-responsive NIR laser treatment. The combination of neuro-specific targeting peptide and external NIR-laser-triggered aid provides a nanoplatform for gene therapy in CNS diseases.

Investigation of the Sequential Actions of Doxorubicin and p53 on Tumor Cell Growth Via Branched Polyethylenimine-β-cyclodextrin Conjugates

The combination of gene therapy and chemotherapy has showed increased therapeutic efficacy in the treatment of cancers, but it is not well investigated about the actual coordination pattern between therapeutic gene and chemical drug. In this work, p53/BPEI-β-CD/AD-dox complex was fabricated and employed to investigate the interaction manner between p53 and doxorubicin (Dox). Briefly, branched polyethylenimine (BPEI) was conjugated with β-cyclodextrin hydrate (β-CD) to form BPEI-β-CD backbone, and p53 plasmid was condensed by positively charged BPEI via electrostatic interaction, while Dox was first conjugated with adamantine (AD) and then assembled with BPEI-β-CD backbone via the host-guest interaction. It was found that the BPEI-β-CD backbone possessed high endocytosis efficiency but low cytotoxicity. Moreover, p53/BPEI-β-CD/AD-dox complex released Dox and enabled the expression of p53 gene in a sequential manner, and the released Dox and expressed p53 gene showed successive inhibition of the growth of HeLa cells in vitro. With the ability to co-deliver chemical drug and therapeutic gene and exert their inhibitory actions on tumor cell growth in a sequential manner, this DNA/BPEI-β-CD/AD-drug complex via electrostatic interaction and host-guest assembly not only achieved long-term efficacy in inhibiting tumor cell growth but also can be employed as a platform to investigate the coordination pattern between chemical drugs and therapeutic genes for other purposes.

Micro and nanotechnologies in heart valve tissue engineering

Due to the increased morbidity and mortality resulting from heart valve diseases, there is a growing demand for off-the-shelf implantable tissue engineered heart valves (TEHVs). Despite the significant progress in recent years in improving the design and performance of TEHV constructs, viable and functional human implantable TEHV constructs have remained elusive. The recent advances in micro and nanoscale technologies including the microfabrication, nano-microfiber based scaffolds preparation, 3D cell encapsulated hydrogels preparation, microfluidic, micro-bioreactors, nano-microscale biosensors as well as the computational methods and models for simulation of biological tissues have increased the potential for realizing viable, functional and implantable TEHV constructs. In this review, we aim to present an overview of the importance and recent advances in micro and nano-scale technologies for the development of TEHV constructs.

Single-Layered MoS2-PEI-PEG Nanocomposite-Mediated Gene Delivery Controlled by Photo and Redox Stimuli

Stimuli-responsive gene delivery systems maximize therapeutic efficacy by controlling the cytosolic conveyance and rate of effective gene release. We present herein a hybrid nanocomposite composed of a 2D nanomaterial, MoS2, modified by attaching two polymers (polyethylenimine (PEI) and polyethylenglycol (PEG)) via disulfide bonds. This MoS2-PEI-PEG nanocomposite interacts with DNA by electrostatic interaction, and accordingly forms a nanosized complex with high stability. Photothermal conversion of MoS2 nanosheet is employed in order to induce photothermally triggered endosomal escape upon the near infrared light irradiation. After endosomal escape, polymers are detached from the MoS2 nanosheet by the intracellular reducing agent, glutathione (GSH), resulting in effective gene release from the nanocomposite. This sequential process initiated by external and internal stimuli remarkably enhances gene delivery efficiency by effective endosomal escape and gene release without severe cytotoxicity. Our rationally designed MoS2 nanocomposite provides a spatiotemporally controllable platform to deliver genetic material into cells.

Synergistic nanomedicine by combined gene and photothermal therapy

To date, various nanomaterials with the ability for gene delivery or photothermal effect have been developed in the field of biomedicine. The therapeutic potential of these nanomaterials has raised considerable interests in their use in potential next-generation strategies for effective anticancer therapy. In particular, the advancement of novel nanomedicines utilizing both therapeutic strategies of gene delivery and photothermal effect has generated much optimism regarding the imminent development of effective and successful cancer treatments. In this review, we discuss current research progress with regard to combined gene and photothermal therapy. This review focuses on synergistic therapeutic systems combining gene regulation and photothermal ablation as well as logically designed nano-carriers aimed at enhancing the delivery efficiency of therapeutic genes using the photothermal effect. The examples detailed in this review provide insight to further our understanding of combinatorial gene and photothermal therapy, thus paving the way for the design of promising nanomedicines.

An Overview of Nanoparticle Based Delivery for Treatment of Inner Ear Disorders

Nanoparticles offer new possibilities for inner ear treatment as they can carry a variety of drugs, protein, and nucleic acids to inner ear. Nanoparticles are equipped with several functions such as targetability, immuno-transparency, biochemical stability, and ability to be visualized in vivo and in vitro. A group of novel peptides can be attached to the surface of nanoparticles that will enhance the cell entry, endosomal escape, and nuclear targeting. Eight different types of nanoparticles with different payload carrying strategies are available now. The transtympanic delivery of nanoparticles indicates that, depending on the type of nanoparticle, different migration pathways into the inner ear can be employed, and that optimal carriers can be designed according to the intended cargo. The use of nanoparticles as drug/gene carriers is especially attractive in conjunction with cochlear implantation or even as an inclusion in the implant as a drug/gene reservoir.

Recent advances in superparamagnetic iron oxide nanoparticles (SPIONs) for in vitro and in vivo cancer nanotheranostics

Recently superparamagnetic iron oxide nanoparticles (SPIONs) have been extensively used in cancer therapy and diagnosis (theranostics) via magnetic targeting, magnetic resonance imaging, etc. due to their remarkable magnetic properties, chemical stability, and biocompatibility. However, the magnetic properties of SPIONs are influenced by various physicochemical and synthesis parameters. So, this review mainly focuses on the influence of spin canting effects, introduced by the variations in size, shape, and organic/inorganic surface coatings, on the magnetic properties of SPIONs. This review also describes the several predominant chemical synthesis procedures and role of the synthesis parameters for monitoring the size, shape, crystallinity and composition of the SPIONs. Moreover, this review discusses about the latest developments of the inorganic materials and organic polymers for encapsulation of the SPIONs. Finally, the most recent advancements of the SPIONs and their nanopackages in combination with other imaging/therapeutic agents have been comprehensively discussed for their effective usage as in vitro and in vivo theranostic agents in cancer treatments.

Antitumor effect of TRAIL on oral squamous cell carcinoma using magnetic nanoparticle-mediated gene expression

We developed a new magnetic nanovector to improve the efficiency and targeting of transgene therapy for oral squamous cell carcinoma (OSCC). Positively charged polymer PEI-modified Fe(3)O(4) magnetic nanoparticles were tested as gene transfer vectors in the presence of a magnetic field. The Fe(3)O(4) nanoparticles were prepared by a co-precipitation method and had good dispersibility in water. These nanoparticles modified by PEI were combined with negatively charged pACTERT-EGFP via electrostatic interaction. The transfection efficiency of the magnetic nano-gene vector with the magnetic field was determined by a fluorescence-inverted microscope and flow cytometry. The results showed significant improvement compared with the control group (p < 0.05). The magnetic complexes also exhibited up to 6-times higher transfection efficiency compared with commonly used PEI or lipofectin. On the basis of these results, the antitumor effect with suicide gene therapy using pACTERT-TRAIL in vitro and vivo was evaluated. In vitro apoptosis was determined with the Annexin V-FITC Apoptosis Detection Kit. The results suggested that PEI-modified Fe(3)O(4) nanoparticles could mediate the killing of Tca83 cells. Furthermore, treatment with pACTERT-TRAIL delivered by magnetic nanoparticles showed a significant cytostatic effect through the induction of apoptosis in a xenograft model. This indicates that magnetic nano-gene vectors could improve the transgene efficiency for Tca83 cells and could exhibit antitumor functions with the plasmid pACTERT-TRAIL. This may be a new way to treat OSCC.

Branched Polyethylenimine-Superparamagnetic Iron Oxide Nanoparticles (bPEI-SPIONs) Improve the Immunogenicity of Tumor Antigens and Enhance Th1 Polarization of Dendritic Cells

Nanoparticles in the field of dendritic cell (DC) research are emerging as a promising method of enhancing the efficacy of cancer immunotherapy. We investigated the effect of branched polyethylenimine-superparamagnetic iron oxide nanoparticles (bPEI-SPIONs) on tumor cells loaded onto DCs. The tumor antigens were prepared as follows: (1) apoptotic U266 cells with ultraviolet B (UVB) irradiation followed by a 2 h incubation in the absence (2 h postirradiated cells) or (2) presence of bPEI-SPIONs (bPEI-SPION 2 h postirradiated cells) and (3) apoptotic U266 cells with UVB irradiation followed by an overnight 16 h incubation (16 h postirradiated cells). bPEI-SPIONs render U266 cells sensitive to UVB irradiation through reactive oxygen species production to accelerate apoptotic death. The 2 h postirradiated cells and bPEI-SPION 2 h postirradiated cells released immunogenic proteins, including Hsp70, Hsp90, and HMGB1. The DCs loaded with bPEI-SPION 2 h postirradiated cells showed the highest IL-12p70 production and Th1 polarization compared with other DCs. These results suggest that bPEI-SPIONs are a promising method of enhancing the immunogenicity of tumor cells and promoting Th1 polarization of DCs loaded with these tumor cells.

Polysaccharide-Coated Magnetic Nanoparticles for Imaging and Gene Therapy

Today, nanotechnology plays a vital role in biomedical applications, especially for the diagnosis and treatment of various diseases. Among the many different types of fabricated nanoparticles, magnetic metal oxide nanoparticles stand out as unique and useful tools for biomedical applications, because of their imaging characteristics and therapeutic properties such as drug and gene carriers. Polymer-coated magnetic particles are currently of particular interest to investigators in the fields of nanobiomedicine and fundamental biomaterials. Theranostic magnetic nanoparticles that are encapsulated or coated with polymers not only exhibit imaging properties in response to stimuli, but also can efficiently deliver various drugs and therapeutic genes. Even though a large number of polymer-coated magnetic nanoparticles have been fabricated over the last decade, most of these have only been used for imaging purposes. The focus of this review is on polysaccharide-coated magnetic nanoparticles used for imaging and gene delivery.