Development of biomaterials for gene therapy

Advanced gene nanocarriers/scaffolds in nonviral-mediated delivery system for tissue regeneration and repair

Tissue regeneration technology has been rapidly developed and widely applied in tissue engineering and repair. Compared with traditional approaches like surgical treatment, the rising gene therapy is able to have a durable effect on tissue regeneration, such as impaired bone regeneration, articular cartilage repair and cancer-resected tissue repair. Gene therapy can also facilitate the production of in situ therapeutic factors, thus minimizing the diffusion or loss of gene complexes and enabling spatiotemporally controlled release of gene products for tissue regeneration. Among different gene delivery vectors and supportive gene-activated matrices, advanced gene/drug nanocarriers attract exceptional attraction due to their tunable physiochemical properties, as well as excellent adaptive performance in gene therapy for tissue regeneration, such as bone, cartilage, blood vessel, nerve and cancer-resected tissue repair. This paper reviews the recent advances on nonviral-mediated gene delivery systems with an emphasis on the important role of advanced nanocarriers in gene therapy and tissue regeneration.

Aptamer-modified tetrahedral DNA nanostructure-immobilized liposome for specific gene delivery and potential cancer theragnostic

Targeted delivery of therapeutic agents to cancer cells is crucial for effective cancer treatment without adverse effects. In this study, we developed a novel delivery carrier, Aptamer-modified tetrahedral DNA nanostructure (TDN) immobilized Liposome (ApTL), for specific delivery to nucleolin-overexpressing cancer cells. We demonstrated that targeted ApTL was highly effective in delivering plasmid and mRNA to nucleolin-overexpressing cancer cells compared to non-targeted ApTL with a non-specific aptamer. ApTL, which is highly negative and nano-sized, specifically delivered nucleic acids to MDA-MB-231 and HeLa cancer cells, primarily via lipid-raft-mediated endocytosis. Furthermore, the co-delivery of mRNA and doxorubicin resulted in increased apoptosis and reduced cancer cell viability. Interestingly, co-delivery of mRNA and Dox did not show a significant difference in EGFP expression at 24 h but dramatically increased EGFP expression at 48 h, making ApTL/mEGFP/Dox a promising candidate for detecting live cancer cells after targeted cancer drug treatment. Our results suggest that ApTL can be a promising tool for the targeted delivery of therapeutic agents to nucleolin-overexpressing cancer cells, providing a new strategy for cancer theragnostic.

siRNA-Based Novel Therapeutic Strategies to Improve Effectiveness of Antivirals: An Insight

Since the ground-breaking discovery of RNA interference (RNAi), scientists have made significant progress in the field of small interfering RNA (siRNA) treatments. Due to severe barriers to the therapeutic application of siRNA, nanoparticle technologies for siRNA delivery have been designed. For pathological circumstances such as viral infection, toxic RNA abnormalities, malignancies, and hereditary diseases, siRNAs are potential therapeutic agents. However, systemic administration of siRNAs in vivo remains a substantial issue due to a lack of "drug-likeness" (siRNA are relatively larger than drugs and have low hydrophobicity), physiological obstacles, and possible toxicities. This write-up covers important accomplishment in the field of clinical trials and patents specially based of siRNAs using targeting viruses. Furthermore, it offers deep insight of nanoparticle applied for siRNA delivery and strategies to improve the effectiveness of antivirals.

Purity and DNA content of AAV capsids assessed by analytical ultracentrifugation and orthogonal biophysical techniques

Development and manufacturing adeno-associated virus (AAV)-based vectors for gene therapy requires suitable analytical methods to assess the quality of the formulations during development, as well as the quality of different batches and the consistency of the processes. Here, we compare biophysical methods to characterize purity and DNA content of viral capsids from five different serotypes (AAV2, AAV5, AAV6, AAV8, and AAV9). For this purpose, we apply multiwavelength sedimentation velocity analytical ultracentrifugation (SV-AUC) to obtain the species' contents and to derive the wavelength-specific correction factors for the respective insert-size. In an orthogonal manner we perform anion exchange chromatography (AEX) and UV-spectroscopy and the three methods yield comparable results on empty/filled capsid contents with these correction factors. Whereas AEX and UV-spectroscopy can quantify empty and filled AAVs, only SV-AUC could identify the low amounts of partially filled capsids present in the samples used in this study. Finally, we employ negative-staining transmission electron microscopy and mass photometry to support the empty/filled ratios with methods that classify individual capsids. The obtained ratios are consistent throughout the orthogonal approaches as long as no other impurities and aggregates are present. Our results show that the combination of selected orthogonal methods can deliver consistent empty/filled contents on non-standard genome sizes, as well as information on other relevant critical quality attributes, such as AAV capsid concentration, genome concentration, insert size length and sample purity to characterize and compare AAV preparations.

Dendrimers: Advancements and Potential Applications in Cancer Diagnosis and Treatment-An Overview

Cancer is a leading cause of death worldwide, and the main treatment methods for this condition are surgery, chemotherapy, and radiotherapy. These treatment methods are invasive and can cause severe adverse reactions among organisms, so nanomaterials are increasingly used as structures for anticancer therapies. Dendrimers are a type of nanomaterial with unique properties, and their production can be controlled to obtain compounds with the desired characteristics. These polymeric molecules are used in cancer diagnosis and treatment through the targeted distribution of some pharmacological substances. Dendrimers have the ability to fulfill several objectives in anticancer therapy simultaneously, such as targeting tumor cells so that healthy tissue is not affected, controlling the release of anticancer agents in the tumor microenvironment, and combining anticancer strategies based on the administration of anticancer molecules to potentiate their effect through photothermal therapy or photodynamic therapy. The purpose of this review is to summarize and highlight the possible uses of dendrimers regarding the diagnosis and treatment of oncological conditions.

Porous biomaterials for tissue engineering: a review

The field of biomaterials has grown rapidly over the past decades. Within this field, porous biomaterials have played a remarkable role in: (i) enabling the manufacture of complex three-dimensional structures; (ii) recreating mechanical properties close to those of the host tissues; (iii) facilitating interconnected structures for the transport of macromolecules and cells; and (iv) behaving as biocompatible inserts, tailored to either interact or not with the host body. This review outlines a brief history of the development of biomaterials, before discussing current materials proposed for use as porous biomaterials and exploring the state-of-the-art in their manufacture. The wide clinical applications of these materials are extensively discussed, drawing on specific examples of how the porous features of such biomaterials impact their behaviours, as well as the advantages and challenges faced, for each class of the materials.

Challenges and progress toward tumor-targeted therapy by systemic delivery of polymer-complexed oncolytic adenoviruses

Oncolytic adenovirus (oAd) elicits antitumor activity by preferential viral replication in cancer cells. However, poor systemic administrability or suboptimal intratumoral retainment of the virus remains a major challenge toward maximizing the antitumor activity of oAd in a clinical environment. To surmount these issues, a variety of non-immunogenic polymers has been used to modify the surface of oAds chemically or physically. Complexation of oAd with polymers can effectively evade the host immune response and reduces nonspecific liver sequestration. The tumor-specific delivery of these complexes can be further improved upon by inclusion of tumor-targeting moieties on the surface. Therefore, modification of the Ad surface using polymers is viewed as a potential strategy to enhance the delivery of Ad via systemic administration. This review aims to provide a comprehensive overview of polymer-complexed Ads, their progress, and future challenges in cancer treatment.

Scavenger receptor-targeted plaque delivery of microRNA-coated nanoparticles for alleviating atherosclerosis

Atherosclerosis treatments by gene regulation are garnering attention, yet delivery of gene cargoes to atherosclerotic plaques remains inefficient. Here, we demonstrate that assembly of therapeutic oligonucleotides into a three-dimensional spherical nucleic acid nanostructure improves their systemic delivery to the plaque and the treatment of atherosclerosis. This noncationic nanoparticle contains a shell of microRNA-146a oligonucleotides, which regulate the NF-κB pathway, for achieving transfection-free cellular entry. Upon an intravenous injection into apolipoprotein E knockout mice fed with a high-cholesterol diet, this nanoparticle naturally targets class A scavenger receptor on plaque macrophages and endothelial cells, contributing to elevated delivery to the plaques (∼1.2% of the injected dose). Repeated injections of the nanoparticle modulate genes related to immune response and vascular inflammation, leading to reduced and stabilized plaques but without inducing severe toxicity. Our nanoparticle offers a safe and effective treatment of atherosclerosis and reveals the promise of nucleic acid nanotechnology for cardiovascular disease.

Deagglomeration of DNA nanomedicine carriers using controlled ultrasonication

Control over the agglomeration state of manufactured particle systems for drug and oligonucleotide intracellular delivery is paramount to ensure reproducible and scalable therapeutic efficacy. Ultrasonication is a well-established mechanism for the deagglomeration of bulk powders in dispersion. Its use in manufacturing requires strict control of the uniformity and reproducibility of the cavitation field within the sample volume to minimise within-batch and batch-to-batch variability. In this work, we demonstrate the use of a reference cavitating vessel which provides stable and reproducible cavitation fields over litre-scale volumes to assist the controlled deagglomeration of a novel non-viral particle-based plasmid delivery system. The system is the Nuvec delivery platform, comprising polyethylenimine-coated spiky silica particles with diameters of ∼ 200 nm. We evaluated the use of controlled cavitation at different input powers and stages of preparation, for example before and after plasmid loading. Plasmid loading was confirmed by X-ray photoelectron spectroscopy and gel electrophoresis. The latter was also used to assess plasmid integrity and the ability of the particles to protect plasmid from potential degradation caused by the deagglomeration process. We show the utility of laser diffraction and differential centrifugal sedimentation in quantifying the efficacy of product de-agglomeration in the microscale and nanoscale size range respectively. Transmission electron microscopy was used to assess potential damages to the silica particle structure due to the sonication process.

A boronate-based modular assembly nanosystem to block the undesirable crosstalk between hepatic stellate cells and Kupffer cells

Crosstalk between Kupffer cells (KCs) and hepatic stellate cells (HSCs) plays an important role in multiple liver disease conditions, including the formation of liver fibrosis in alcohol-associated liver disease (AALD). Therapeutic targeting of the KC-HSC crosstalk is a prime target for therapeutic interventions. Herein, a novel modular nanosystem was designed and prepared through the self-assembly utilizing boric acid and catechol interactions to prepare polymers modified with a CXCR4-inhibiting moieties. The polymers were used to encapsulate anti-miR-155 and to block the undesirable crosstalk between HSCs and KCs by downregulating miR-155 expression in KCs with the parallel inhibition of CXCR4 signaling in activated HSCs. The combined inhibition of miR-155 and CXCR4 at two different liver cell types achieved improved antifibrosis effects in a mouse model of AALD fibrosis. Our finding highlights the key role that blocking the undesirable crosstalk between HSCs and KCs plays in reversing AALD fibrosis as well as demonstrates a proof-of-concept approach for designing and constructing multifunctional delivery nanosystems using orthogonal functional modules based on the understanding of disease mechanisms.

Gene Therapy: The Next-Generation Therapeutics and Their Delivery Approaches for Neurological Disorders

Neurological conditions like neurodevelopmental disorders and neurodegenerative diseases are quite complex and often exceedingly difficult for patients. Most of these conditions are due to a mutation in a critical gene. There is no cure for the majority of these neurological conditions and the availability of disease-modifying therapeutics is quite rare. The lion's share of the treatments that are available only provide symptomatic relief, as such, we are in desperate need of an effective therapeutic strategy for these conditions. Considering the current drug development landscape, gene therapy is giving us hope as one such effective therapeutic strategy. Consistent efforts have been made to develop gene therapy strategies using viral and non-viral vectors of gene delivery. Here, we have discussed both of these delivery methods and their properties. We have summarized the relative advantages and drawbacks of viral and non-viral vectors from the perspectives of safety, efficiency, and productivity. Recent developments such as clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-mediated gene editing and its use in vivo have been described here as well. Given recent advancements, gene therapy shows great promise to emerge as a next-generation therapeutic for many of the neurodevelopmental and neurodegenerative conditions.

Hydrophilic nanoparticles that kill bacteria while sparing mammalian cells reveal the antibiotic role of nanostructures

To dissect the antibiotic role of nanostructures from chemical moieties belligerent to both bacterial and mammalian cells, here we show the antimicrobial activity and cytotoxicity of nanoparticle-pinched polymer brushes (NPPBs) consisting of chemically inert silica nanospheres of systematically varied diameters covalently grafted with hydrophilic polymer brushes that are non-toxic and non-bactericidal. Assembly of the hydrophilic polymers into nanostructured NPPBs doesn't alter their amicability with mammalian cells, but it incurs a transformation of their antimicrobial potential against bacteria, including clinical multidrug-resistant strains, that depends critically on the nanoparticle sizes. The acquired antimicrobial potency intensifies with small nanoparticles but subsides quickly with large ones. We identify a threshold size (d_silica ~ 50 nm) only beneath which NPPBs remodel bacteria-mimicking membrane into 2D columnar phase, the epitome of membrane pore formation. This study illuminates nanoengineering as a viable approach to develop nanoantibiotics that kill bacteria upon contact yet remain nontoxic when engulfed by mammalian cells.

Carbon dot composites for bioapplications: a review

Recent advancements in the synthesis of carbon dot composites and their applications in biomedical fields (bioimaging, drug delivery and biosensing) have been carefully summarized. The current challenges and future trends of CD composites in this field have also been discussed.

Fabrication and Biological Activities of Plasmid DNA Gene Carrier Nanoparticles Based on Biodegradable l-Tyrosine Polyurethane

Gene therapy is a suitable alternative to chemotherapy due to the complications of drug resistance and toxicity of drugs, and is also known to reduce the occurrence of cellular mutation through the use of gene carriers. In this study, gene carrier nanoparticles with minimal toxicity and high transfection efficiency were fabricated from a biocompatible and biodegradable polymer, l-tyrosine polyurethane (LTU), which was polymerized from presynthesized desaminotyrosyl tyrosine hexyl ester (DTH) and polyethylene glycol (PEG), by using double emulsion and solvent evaporation techniques, resulting in the formation of porous nanoparticles, and then used to evaluate their potential biological activities through molecular controlled release and transfection studies. To assess cellular uptake and transfection efficiency, two model drugs, fluorescently labeled bovine serum albumin (FITC-BSA) and plasmid DNA-linear polyethylenimine (LPEI) complex, were successfully encapsulated in nanoparticles, and their transfection properties and cytotoxicities were evaluated in LX2 as a normal cell and in HepG2 and MCF7 as cancer cells. The morphology and average diameter of the LTU nanoparticles were confirmed using light microscopy, transmission electron microscopy, and dynamic light scattering, while confocal microscopy was used to validate the cellular uptake of FITC-BSA-encapsulated LTU nanoparticles. Moreover, the successful cellular uptake of LTU nanoparticles encapsulated with pDNA-LPEI and the high transfection efficiency, confirmed by gel electrophoresis and X-gal assay transfection, indicated that LTU nanoparticles had excellent cell adsorption ability, facilitated gene encapsulation, and showed the sustained release tendency of genes through transfection experiments, with an optimal concentration ratio of pDNA and LPEI of 1:10. All the above characteristics are ideal for gene carriers designed to transport and release drugs into the cytoplasm, thus facilitating effective gene therapy.

Further Studies on Cationic Gemini Amphiphiles as Carriers for Gene Delivery-The Effect of Linkers in the Structure and Other Factors Affecting the Transfection Efficacy of These Amphiphiles

Gene therapy has the therapeutic potential to address a multitude of health problems, and it also has utility in different domains of science. However, its applications are plagued due to the absence of a suitable, safe, efficient, selective, and universal vector, which could help in delivering the desired nucleic acid cargo to the site of action. Though viral vectors are efficient, they pose various health risks. Different types of synthetic agents have been tried as nucleic acid vectors by researchers but with limited success. Gemini amphiphiles (GAs) are a class of synthetic surfactants having biscationic heads with attached hydrophilic and lipophilic groups. Herein, we synthesized two classes of GAs differing in the chemical nature and length of the linkers, head groups, and lipophilic chains. The resulting compounds were evaluated for their efficiency to transfect A549 and HeLa cell lines with a β-galactosidase reporter plasmid. A 3-oxypentyl linker, a monohydroxyethyl head group, and a tetradecyl moiety as the lipophilic chain offered the best transfection efficiency (compound 10BIII). Dioleoylphosphatidylethanolamine (DOPE) as the helper lipid improved the transfection efficacy of the GAs in the absence of serum. In the presence of serum, DOPE and cholesterol, as the helper lipids, improved the transfection efficacy of the resulting formulations. The synthesized GAs showed concentration-dependent toxicity in the MTT assay. Biodistribution studies using 99mTc-labeled lipoplexes indicated that the lipoplexes got concentrated in some vital organs such as the spleen, liver, and lungs.

An electrochemical genosensor for differentiation of fully methylated from fully unmethylated states of BMP3 gene

The methylation state of a part of the BMP3 gene was detected by our genosensor. This epigenetic biomarker is involved in the biomarker panel of the sDNA test, which is an FDA approved test for colorectal cancer screening. In the present genosensor, polyethyleneimine-stabilized silver nanoparticles (PEI-AgNPs) were used as a non-specific nanolabel for signal generation/amplification and lowering the limit of detection. After immobilization of capture probes and mercaptoethanol molecules on the gold electrode, a thermally treated mixture of the BMP3 targets and reporter probes was introduced to the electrode. Because of the specificity of the reporter probes for fully methylated targets, complete sandwich-like complexes are formed only with them. Therefore, such full-length double-stranded hybrids compared to fully unmethylated targets have more negative charges and can more attract positively charged PEI-AgNPs. For discrimination between methylated and unmethylated targets, electroimpedance spectroscopy and cyclic voltammetry were used for electrode modification monitoring and signal measurement. The sharp and narrow anodic peaks of cyclic voltammograms, which resulted from silver oxidation, were utilized for calibration plot analysis. The genosensor showed a linear response for the target concentration range from 1fM to 100 nM, while the detection limit for methylated and unmethylated target discrimination was 1 fM.

Magnetic Copper Ferrite Nanoparticles Functionalized by Aromatic Polyamide Chains for Hyperthermia Applications

A new magnetic nanocomposite with a statistical star polymer structure was designed and synthesized. Nanocomposite fabrication is based on the polymerization of aromatic polyamide chains on the surface of functionalized magnetic copper ferrite nanoparticles (CuFe₂O₄ MNPs). This magnetic nanostructure was characterized by several analysis methods. All the analytical methods used, for instance, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, thermogravimetric, vibrating-sample magnetometer, and scanning electron microscopy (SEM), confirmed the formation of polyamide chains. The obtained images from SEM imaging showed a unique nanoflower morphology which was the proper orientation results of synthesized nanoplates. Finally, the magnetic nanostructure showed a good potential for hyperthermia applications, with a maximum specific absorption rate of 7 W/g for 1 mg/mL of the sample under a magnetic field in different frequencies (100, 200, 300, and 400 MHz) and 5 to 20 min time intervals.

Interactions and Dynamics in Aqueous Solutions of pH-Responsive Polymers: A Combined Fluorescence and Dielectric Relaxation Study

Interaction and dynamics of aqueous solutions of pH-responsive smart polymers are investigated via steady-state, time-resolved fluorescence emission spectroscopy with the help of external local reporter coumarin 153 (C153), while MHz to GHz dielectric relaxation spectroscopic (DRS) measurement reports the intrinsic medium relaxation features. A series of pH-responsive random copolymers (DPL-DP60) comprising of a pH-responsive moiety 2-((leucinyl)oxy)ethyl methacrylate (l-Leu-HEMA) and hydrophobic methyl methacrylate (MMA) are synthesized and characterized. A balance between the pH-responsive (l-Leu-HEMA) and the hydrophobic (MMA) content dictates the phase transition pH, which is found to be ∼5-7 for these aqueous copolymer solutions (1 mg/mL). Dynamic light scattering measurements in aqueous solutions of these polymers reflect a small particle size (∼2-8 nm) at solution pH below their individual phase transition pH, while a large particle size (∼140-340 nm) forms beyond their phase transition pH. No signature of a phase transition pH-driven abrupt change in static and dynamic properties of aqueous polymer solutions has been registered from pH-dependent dielectric relaxation as well as solute (C153)-centric fluorescence measurements. A significant impact of varying the l-Leu-HEMA/MMA segment ratio on steady-state fluorescence emission and rotational anisotropy decay of the fluorophore solute (C153) has been observed. MHz to GHz DRS in aqueous solutions of these pH-responsive polymers reflects bulk water-like dielectric features.

Stem Cell Based Exosomes: Are They Effective in Disease or Health?

Exosomes are nano-sized vesicles involved in intercellular communication via delivery of molecules including lipids, nucleic acids, proteins, or other cellular components to distant or neighboring sites. Their ability to pass biological barriers, stability in physiological fluids without degradation, and distinctive affinity to target cells make exosomes very remarkable therapeutic vehicles. Virus-based approaches are some of the most widely used gene therapy methods; however, there are many issues need to be clarified such as high immunogenicity. Using of the exosomes procures the functional transfer of their cargo with minimal intervention from the immune system and it has been reported to be secure and well-tolerated. When the regenerative medicine is taken into consideration, stem cell-based approaches have been aimed to utilize but the general efficacy and safety profile of stem cell therapy has still not been enlightened. At this point, stem cell-derived exosomes exhibit a way to procure cell-free regenerative medicine with their unique characteristics. Exosomes are considered as appropriate and highly stable biological nano-vectors taking part in a wide variety of healthy and pathological processes for advanced targeted therapies. However, there are still crucial obstacles to achieve efficient isolation of large amount of specific and pure exosomes. Thus, large-scale exosome production under good manufacturing practice is required. The purpose of this review is to focus on stem cell-based exosomes for gene delivery and to introduce synthetic exosome-mimics as a potential alternative in the field of targeted gene therapies. Further, we aim to highlight the biobanking and large-scale manufacturing methods of exosomes.

Properties of polyplexes formed between a cationic polymer derived from l-arabinitol and nucleic acids

Polyplexes formed between a cationic polymer, PUArab, and both linear and plasmid DNA were studied. The transfection efficiency of PURarab/pDNA was investigated.

Peptides as a material platform for gene delivery: Emerging concepts and converging technologies

Successful gene therapies rely on methods that safely introduce DNA into target cells and enable subsequent expression of proteins. To that end, peptides are an attractive materials platform for DNA delivery, facilitating condensation into nanoparticles, delivery into cells, and subcellular release to enable protein expression. Peptides are programmable materials that can be designed to address biocompatibility, stability, and subcellular barriers that limit efficiency of non-viral gene delivery systems. This review focuses on fundamental structure-function relationships regarding peptide design and their impact on nanoparticle physical properties, biologic activity, and biocompatibility. Recent peptide technologies utilize multi-dimensional structures, non-natural chemistries, and combinations of peptides with lipids to achieve desired properties and efficient transfection. Advances in DNA cargo design are also presented to highlight further opportunities for peptide-based gene delivery. Modern DNA designs enable prolonged expression compared to traditional plasmids, providing an additional component that can be synergized with peptide carriers for improved transfection. Peptide transfection systems are poised to become a flexible and efficient platform incorporating new chemistries, functionalities, and improved DNA cargos to usher in a new era of gene therapy.

Review on mechanistic strategy of gene therapy in the treatment of disease

Gene therapy has become a revolution and its breakthrough is a corner stone in modern science. This treatment has rising advantages with limited negative aspects. Gene therapy is a therapeutic method in which, transfer of DNA to an individual to manipulate a defective gene is performed and to mitigate a disease which is not responding to pharmacological therapy. The gene therapy strategies are divided into two main categories such as direct in-vivo gene delivery of manipulated viral vector vehicle into the host and ex-vivo genetically engineered stem cells. In this review, we tried to cover all aspects of gene therapy studies; starting with the concept of gene, its treatment, gene delivery system and types, clinical trial either by vitro or In-Vivo -Clinical Trials and Clinical Intoxication of Gene Therapy. Therefore, the promise of successful treatment with gene therapy could positively affect millions of lives. The main aim of this review is to address the principles of gene therapy, various methods involved in the gene therapy, clinical applications and its merits and demerits.

Efficient Delivery of Transducing Polymer Nanoparticles for Gene-Mediated Induction of Osteogenesis for Bone Regeneration

Developing non-viral gene therapy vectors that both protect and functionally deliver nucleic acid cargoes will be vital if gene augmentation and editing strategies are to be effectively combined with advanced regenerative medicine approaches. Currently such methodologies utilize high concentrations of recombinant growth factors, which result in toxicity and off-target effects. Herein we demonstrate the use of modified cell penetrating peptides (CPPs), termed Glycosaminoglycan (GAG)-binding Enhanced Transduction (GET) peptides with plasmid DNA (pDNA) encapsulated poly (lactic-co-glycolic acid) PLGA nanoparticles (pDNA-encapsulated PLGA NPs). In order to encapsulate the pDNA, it was first condensed with a cationic low molecular weight Poly L-Lysine (PLL) into 30-60 nm NPs followed by encapsulation in PLGA NPs by double emulsion; yielding encapsulation efficiencies (EE) of ∼30%. PLGA NPs complexed with GET peptides show enhanced intracellular delivery (up to sevenfold) and transfection efficiencies (up to five orders of magnitude). Moreover, the pDNA cargo has enhanced protection from nucleases (such as DNase I) promoting their translatability. As an example, we show these NPs efficiently deliver pBMP2 which can promote osteogenic differentiation in vitro. Gene delivery to human Mesenchymal Stromal Cells (hMSCs) inducing their osteogenic programming was confirmed by Alizarin red calcium staining and bone lineage specific gene expression (Q RT-PCR). By combining simplistic and FDA-approved PLGA polymer nanotechnology with the GET delivery system, therapeutic non-viral vectors could have significant impact in future cellular therapy and regenerative medicine applications.

S-Nitroso-N-Acetyl-D-Penicillamine Modified Hyperbranched Polyamidoamine for High-Capacity Nitric Oxide Storage and Release

Synthetic nitric oxide (NO)-donating materials have been shown to have many beneficial effects when incorporated into biomedical materials. When released in the correct dosage, NO has been shown to increase the biocompatibility of blood and tissue contacting materials, but materials are often limited in the amount of NO that can be administered over a period of time. To address this, hyperbranched polyamidoamine (HPAMAM) was modified with the S-nitrosothiol, S-nitroso-N-acetyl-D-penicillamine, and nitrosated to form a controlled, high-capacity NO-donating compound (SNAP-HPAMAM). This compound has the potential of modifying polymers to release NO over long periods of time by being blended into a variety of base polymers. Nitric oxide release was triggered by photoinitiation and through passive ion-mediated release seen under physiological conditions. A material that delivers the beneficial dose of NO over a long period of time would be able to greatly increase the biocompatibility of long-term implantable devices. Structural analysis of a generation 2 HPAMAM molecule was done through Fourier transform infrared spectroscopy (FTIR), 1H nuclear magnetic resonance spectroscopy (NMR), and matrix assisted laser desorption ionization, time of flight (MALDI-TOF) mass spectrometry. The NO capacity of the finalized generation 2 SNAP-HPAMAM compound was approximately 1.90 ± 0.116 µmol NO/mg. Quantification of the functional groups in the compound proved that an average of 6.40 ± 0.309 reactive primary amine sites were present compared to the 8 reactive sites on a perfectly synthesized generation 2 dendrimer. There is a substantial advantage of using the hyper-branched HPAMAM over purified dendrimers in terms of reduced labor and expense while still providing a high-capacity NO donor that can be blended into different polymer matrices.

Genome Editing with mRNA Encoding ZFN, TALEN, and Cas9

Genome-editing technologies based on programmable nucleases have significantly broadened our ability to make precise and direct changes in the genomic DNA of various species, including human cells. Delivery of programmable nucleases into the target tissue or cell is one of the pressing challenges in transforming the technology into medicine. In vitro-transcribed (IVT) mRNA-mediated delivery of nucleases has several advantages, such as transient expression with efficient in vivo and in vitro delivery, no genomic integration, a potentially low off-target rate, and high editing efficiency. This review focuses on key barriers related to IVT mRNA delivery, on developed modes of delivery, and on the application and future prospects of mRNA encoding nuclease-mediated genome editing in research and clinical trials.

Multilayer Capsules Inside Biological Systems: State-of-the-Art and Open Challenges

There are many reports about the interaction of multilayer capsules with biological systems in the literature. A majority of them are devoted to the in vitro study with two-dimensional cell cultures. Multilayer capsule fabrication had been under intensive investigation from 1990s and 2000s by Prof. Helmuth Möhwald, and many of his followers further developed their own research directions, focusing on capsule implementation in various fields of biology and medicine. The aim of this future article is to consistently consider the most recent advances in cell-capsule interactions for different biomedical applications, including functionalization of clinically relevant cells, nonviral gene delivery, magnetization of cells to control their movement, and in vivo drug delivery. Finally, the description and discussion of the new trends and perspectives for improved functionalities of capsules in design and functionalization of cell-assisted drug vehicles are the major topics of this work.

Recent advances in the development of gene delivery systems

Background

Gene delivery systems are essentially necessary for the gene therapy of human genetic diseases. Gene therapy is the unique way that is able to use the adjustable gene to cure any disease. The gene therapy is one of promising therapies for a number of diseases such as inherited disorders, viral infection and cancers. The useful results of gene delivery systems depend open the adjustable targeting gene delivery systems. Some of successful gene delivery systems have recently reported for the practical application of gene therapy.

Main body

The recent developments of viral gene delivery systems and non-viral gene delivery systems for gene therapy have briefly reviewed. The viral gene delivery systems have discussed for the viral vectors based on DNA, RNA and oncolytic viral vectors. The non-viral gene delivery systems have also treated for the physicochemical approaches such as physical methods and chemical methods. Several kinds of successful gene delivery systems have briefly discussed on the bases of the gene delivery systems such as cationic polymers, poly(L-lysine), polysaccharides, and poly(ethylenimine)s.

Conclusion

The goal of the research for gene delivery system is to develop the clinically relevant vectors such as viral and non-viral vectors that use to combat elusive diseases such as AIDS, cancer, Alzheimer, etc. Next step research will focus on advancing DNA and RNA molecular technologies to become the standard treatment options in the clinical area of biomedical application.

Application of Ultrasound-Targeted Microbubble Destruction-Mediated Exogenous Gene Transfer in Treating Various Renal Diseases

Chronic renal disease or acute renal injury could result in end-stage renal disease or renal failure. Sonoporation, induced by ultrasound-targeted microbubble destruction (UTMD), has evolved as a new technology for gene delivery. It increases the transfection efficiency of the genes into target kidney tissues. Moreover, UTMD-mediated gene delivery can directly repair the damaged tissues or improve the recruitment and homing of stem cells in the recovery of injured tissues, which has the potential to act as a non-viral and effective method to current gene therapy. This article reviews the mechanisms and applications of UTMD in terms of renal disease, including diabetic nephropathy, renal carcinoma, acute kidney injury, renal interstitial fibrosis, nephrotoxic nephritis, urinary stones, and acute rejection.

Cationic Hyperbranched Polymers with Biocompatible Shells for siRNA Delivery

Cationic hyperbranched polymers (HBP) were prepared by self-condensing vinyl polymerization of an atom transfer radical polymerization (ATRP) inimer containing a quaternary ammonium group. Two types of biocompatible shells, poly(oligoethylene glycol) methacrylate (polyOEGMA) and poly(2-(methylsulfinyl) ethyl methacrylate) (polyDMSO), were grafted respectively from HBP core to form core-shell structures with low molecular weight dispersity and high biocompatibility, polyOEGMA-HBP and polyDMSO-HBP. Both of the structures showed low cytotoxicity and good siRNA complexing ability. The efficacy of gene silencing against Runt-related transcription factor 2 ( Runx2) expression and the long-term assessment of mineralized nodule formation in osteoblast cultures were evaluated. The biocompatible core-shell structures were crucial to minimizing undesired cytotoxicity and nonspecific gene suppression. polyDMSO-HBP showed higher efficacy of forming polyplexes than polyOEGMA-HBP due to shell with lower steric hindrance. Overall, the gene silencing efficiency of both core-shell structures was comparable to commercial agent Lipofectamine, indicating long-term potential for gene silencing to treat heterotopic ossification (HO).

Bifunctionally engineered polyethylenimines as efficient DNA carriers and antibacterials against resistant pathogens

In this study, we have designed and developed two series of bifunctional conjugates by tethering polyethylenimine with streptomycin. By varying the amount of streptomycin, conjugates, polyethylenimine-streptomycin, have been synthesized and characterized spectroscopically. Gel electrophoresis assay revealed a slight decrease in the cationic charge density on the conjugates as these retarded the mobility of pDNA at higher w/w ratios. Further, transfection studies showed that both the series of conjugates transfected the mammalian cells efficiently with low-molecular weight polyethylenimine-streptomycin conjugates were more competent (∼9-fold enhancement with respect to native bPEI) exhibiting high cell viability too. Besides, both the series of conjugates displayed excellent antibacterial activity on pathogenic bacteria, even better than native streptomycin on resistant strains. Altogether, these results ensure the promising potential of the projected bifunctional conjugates as safe and efficient gene delivery vectors as well as antibacterials for future biomedical applications.

Delivery of Small Interfering RNA. A Review and an Example of Application to a Junction Oncogene

RNA interference strategies using small interfering RNA is one of the most important discoveries in biology in recent years. This technology alongside antisense oligonucleotides is very promising and our group has focused its work on the targeting of junction oncogenes with these molecules. We have taken, as first example, papillary thyroid carcinoma. But there is a great need in delivery methods for these molecules in the treatment of cancers. Indeed, many studies have shown that small interfering RNA and antisense oligonucleotides are made efficient by various innovative delivery methods and, under these conditions, offer a powerful new therapeutic tool in cancer treatment.

Influence of additives on thermoresponsive polymers in aqueous media: a case study of poly(N-isopropylacrylamide)

Thermoresponsive polymers (TRPs) in different solvent media have been studied over a long period and are important from both scientific and technical points of view.

Biomaterials for Craniofacial Bone Regeneration

Functional reconstruction of craniofacial defects is a major clinical challenge in craniofacial sciences. The advent of biomaterials is a potential alternative to standard autologous/allogenic grafting procedures to achieve clinically successful bone regeneration. This article discusses various classes of biomaterials currently used in craniofacial reconstruction. Also reviewed are clinical applications of biomaterials as delivery agents for sustained release of stem cells, genes, and growth factors. Recent promising advancements in 3D printing and bioprinting techniques that seem to be promising for future clinical treatments for craniofacial reconstruction are covered. Relevant topics in the bone regeneration literature exemplifying the potential of biomaterials to repair bone defects are highlighted.

Mesenchymal Stem Cells Engineering: Microcapsules-Assisted Gene Transfection and Magnetic Cell Separation

Stem cell engineering-the manipulation and functionalization of stem cells involving genetic modification-can significantly expand their applicability for cell therapy in humans. Toward this aim, reliable, standardized, and cost-effective methods for cell manipulation are required. Here we explore the potential of magnetic multilayer capsules to serve as a universal platform for nonviral gene transfer, stem cell magnetization, and magnetic cell separation to improve gene transfer efficiency. In particular, the following experiments were performed: (i) a study of the process of internalization of magnetic capsules into stem cells, including capsule co-localization with established markers of endo-lysosomal pathway; (ii) characterization and quantification of capsule uptake with confocal microscopy, electron microscopy, and flow cytometry; (iii) intracellular delivery of messenger RNA and separation of gene-modified cells by magnetic cell sorting (MACS); and (iv) analysis of the influence of capsules on cell proliferation potential. Importantly, based on the internalization of magnetic capsules, transfected cells became susceptible to external magnetic fields, which made it easy to enrich gene-modified cells using MACS (purity ∼95%), and also to influence their migration behavior. In summary, our results underline the high potential of magnetic capsules in stem cell functionalization, namely (i) to increase gene-transfer efficiency and (ii) to facilitate enrichment and targeting of transfected cells. Finally, we did not observe a negative impact of the capsules used on the proliferative capacity of stem cells, proving their high biocompatibility.

Recombinant elastin-based nanoparticles for targeted gene therapy

Among viruses, lentiviral vectors have been popular vectors for gene delivery due to their efficient mode of gene delivery. However, the non-specific delivery of genes associated with lentiviral vectors may result in undesirable side effects. Here, we propose a heterogeneous nanoparticle delivery system for targeted delivery of lentiviral particles containing a therapeutic gene. The heterogeneous nanoparticles consist of the low density lipoprotein receptor 3 (LDLR3) and the keratinocyte growth factor (KGF), each fused to elastin-like-polypeptides (ELPs), LDLR3-ELP and KGF-ELP, respectively. Our results show that while homogeneous nanoparticles comprising of LDLR3-ELP alone blocked viral transduction, heterogeneous nanoparticles comprising of KGF-ELP and LDLR3-ELP enhanced viral transduction in cells expressing high levels of the KGF receptors compared to cells expressing low levels of KGF receptors. Overall, this novel design may help with the targeting of specific cells that overexpressed growth factor such as KGF receptors.

Optimization of Polyplex Formation between DNA Oligonucleotide and Poly(ʟ-Lysine): Experimental Study and Modeling Approach

The polyplexes formed by nucleic acids and polycations have received a great attention owing to their potential application in gene therapy. In our study, we report experimental results and modeling outcomes regarding the optimization of polyplex formation between the double-stranded DNA (dsDNA) and poly(l-Lysine) (PLL). The quantification of the binding efficiency during polyplex formation was performed by processing of the images captured from the gel electrophoresis assays. The design of experiments (DoE) and response surface methodology (RSM) were employed to investigate the coupling effect of key factors (pH and N/P ratio) affecting the binding efficiency. According to the experimental observations and response surface analysis, the N/P ratio showed a major influence on binding efficiency compared to pH. Model-based optimization calculations along with the experimental confirmation runs unveiled the maximal binding efficiency (99.4%) achieved at pH 5.4 and N/P ratio 125. To support the experimental data and reveal insights of molecular mechanism responsible for the polyplex formation between dsDNA and PLL, molecular dynamics simulations were performed at pH 5.4 and 7.4.

Development of a gene carrier using a triblock co-polyelectrolyte with poly(ethylene imine)-poly(lactic acid)-poly(ethylene glycol)

The success of gene therapy mainly depends on the carriers for effective gene delivery. A non-viral vector using a cationic block co-polyelectrolyte, PEI-PLA-PEG polyethyleneimine-poly(lactic acid)-poly(ethylene glycol)) was developed as a potential gene carrier. The cationic PEI-PLA-PEG showed less toxicity compared to PEI and formed a gene nanocomplex (termed polyplex) by interaction with plasmid DNA or small interference RNA. The polyplex showed smaller particle size and greater positive zeta potential by increasing the high polymer nitrogen/DNA phosphate ratio. The polyplex with a nitrogen/DNA phosphate ratio of 16 or 32 demonstrated higher gene transfection by fluorescence imaging, flow cytometry measurement, and β-galactosidase activity. In particular, the polyplex with therapeutic histone deacetylase small interference RNA at nitrogen/DNA phosphate ratio 16 showed the most favorable properties with definite tumor growth inhibition. The synthetic PEI-PLA-PEG also showed less toxicity and would, therefore, be a great potential gene carrier, particularly given that small interference RNA delivery does not increase the charge density of small interference RNA due to the formation of a stable complex through conjugation with PLA-PEG.

Biomaterials to Facilitate Delivery of RNA Agents in Bone Regeneration and Repair

Bone healing after traumatic injuries or pathological diseases remains an important worldwide problem. In search of safer and more effective approaches to bone regeneration and repair, RNA-based therapeutic agents, specifically microRNAs (miRNAs) and short interfering RNA (siRNA), are beginning to be actively explored. In this review, we summarize current attempts to employ miRNAs and siRNAs in preclinical models of bone repair. We provide a summary of current limitations when attempting to utilize bioactive nucleic acids for therapeutic purposes and position the unique aspects of RNA reagents for clinical bone repair. Delivery strategies for RNA reagents are emphasized and nonviral carriers (biomaterial-based) employed to deliver such reagents are reviewed. Critical features of biomaterial carriers and various delivery technologies centered around nanoparticulate systems are highlighted. We conclude with the authors' perspectives on the future of the field, outlining main critical issues important to address as RNA reagents are explored for clinical applications.

Influence of Poly(Amino Acid) Composition on the Complexation of Plasmid DNA and Transfection Efficiency

Random copolymers of poly[(Lys, Ala) 1: 1], poly[(Lys, Ala) 2: 1], poly[(Lys, Ala) 3: 1], poly[(Lys, Ser) 3: 1] and poly[(Arg, Ser) 3: 1] (ratios designate the feed comonomer composition), were complexed with plasmid DNA pRL CMV luc at different weight per weight DNA: polymer ratios. The physicochemical properties of the complexes were evaluated by gel retardation assay, Zeta potential measurements and photon correlation spectroscopy. The extent of DNA protection against nucleases was determined by a nuclease assay. Cell viability and transfection efficiency of the DNA/polymer complexes were determined by MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-4-sulfophenyl)-2-H -tetrazolium) and luciferase assays, respectively. Regardless of the amino acid feed composition, neutral complexes were formed between 2: 1 and 1: 1 DNA: polymer ratios. The particle sizes of the complexes were in the range of 100-300 nm with complexes with more DNA gave a larger particle size than those with a higher proportion of polymer. Compared to other copolymers, lower amounts of poly[(Lys, Ser) 3: 1] were required to protect the DNA against degradation. The presence of arginine residues increased the transfection efficiency of the complexes by 2-3 orders of magnitude. Results suggest that the amino acid composition of the copolymers has an impact on protection of DNA against degradation by the nucleases, cytotoxicity and transfection efficiency.

Tumor-specific expression of shVEGF and suicide gene as a novel strategy for esophageal cancer therapy

AIM: To develop a potent and safe gene therapy for esophageal cancer.

METHODS: An expression vector carrying fusion suicide gene (yCDglyTK) and shRNA against vascular endothelial growth factor (VEGF) was constructed and delivered into EC9706 esophageal cancer cells by calcium phosphate nanoparticles (CPNP). To achieve tumor selectivity, expression of the fusion suicide gene was driven by a tumor-specific human telomerase reverse transcriptase (hTERT) promoter. The biologic properties and therapeutic efficiency of the vector, in the presence of prodrug 5-fluorocytosine (5-FC), were evaluated in vitro and in vivo.

RESULTS: Both in vitro and in vivo testing showed that the expression vector was efficiently introduced by CPNP into tumor cells, leading to cellular expression of yCDglyTK and decreased VEGF level. With exposure to 5-FC, it exhibited strong anti-tumor effects against esophageal cancer. Combination of VEGF shRNA with the fusion suicide gene demonstrated strong anti-tumor activity.

CONCLUSION: The shVEGF-hTERT-yCDglyTK/5-FC system provided a novel approach for esophageal cancer-targeted gene therapy.