Cellular endocytosis and gene delivery

Efficient and scalable gene delivery method with easily generated cationic carbon dots

Gene delivery is a complex process with several challenges when attempting to incorporate genetic material efficiently and safely into target cells. Some of the key challenges include not only efficient cellular uptake and endosomal escape to ensure that the genetic material can exert its effect but also minimizing the toxicity of the delivery system, which is vital for safe gene delivery. Of importance, if gene delivery systems are intended for biomedical applications or clinical use, they must be scalable and easy and affordable to manufacture to meet the demand. Here, we show an efficient gene delivery method using a combination of carbon dots coated by PEI through electrostatic binding to easily generate cationic carbon dots. We show a biofunctional approach to generate optimal cationic carbon dots (CCDs) that can be scaled up to meet specific transfection demands. CCDs improve cell viability and increase transfection efficiency four times over the standard of PEI polyplexes. Generated CCDs enabled the challenging transfection protocol to produce retroviral vectors via cell cotransfection of three different plasmids into packing cells, showing not only high efficiency but also functionality of the gene delivery, tested as the capacity to produce infective retroviral particles.

Trafficking and effect of released DNA on cGAS-STING signaling pathway and cardiovascular disease

Evidence from clinical research and animal studies indicates that inflammation is an important factor in the occurrence and development of cardiovascular disease (CVD). Emerging evidence shows that nucleic acids serve as crucial pathogen-associated molecular patterns (PAMPs) or non-infectious damage-associated molecular patterns (DAMPs), are released and then recognized by pattern recognition receptors (PRRs), which activates immunological signaling pathways for host defense. Mechanistically, the released nucleic acids activate cyclic GMP-AMP synthase (cGAS) and its downstream receptor stimulator of interferon genes (STING) to promote type I interferons (IFNs) production, which play an important regulatory function during the initiation of an innate immune response to various diseases, including CVD. This pathway represents an essential defense regulatory mechanism in an organism's innate immune system. In this review, we outline the overall profile of cGAS-STING signaling, summarize the latest findings on nucleic acid release and trafficking, and discuss their potential role in CVD. This review also sheds light on potential directions for future investigations on CVD.

Case Report: A recurrent case of ALK-ALCL after autologous transplantation was successfully treated with BV + a modified CHEP chemotherapy containing mitoxantrone hydrochloride liposome with the addition of chidamide maintenance therapy

Background

ALK-negative anaplastic large cell lymphoma (ALK-ALCL) is a rare heterogeneous malignancy of T-cell origin.ALK- ALCL has a poor prognosis, with more patients experiencing relapses and refractory to treatment, and its treatment remains challenging. We report a case with bone involvement as the main clinical manifestation of recurrent, and the patient achieved significant partial remission after brentuximab vedotin(BV) combined with a modified CHEP chemotherapy containing mitoxantrone hydrochloride liposome (PLM60) with the addition of chidamide maintenance therapy and received regular follow-up, with a disease-free survival of 16 months to date. A literature review of the clinical presentation and treatment of ALCL was also conducted to identify strategies for its diagnosis and management.

Conclusions

ALK-ALCL with bone involvement as the main manifestation of recurrent is relatively rare. Here, BV combined a modified CHEP chemotherapy containing mitoxantrone hydrochloride liposome was applied for the first time in a patient with relapsed ALK-ALCL, inducing remission and extending survival. However, further prospective studies with many patients are needed to determine the biological characteristics of this rare type of ALK-ALCL and relevant treatment strategies.

Gene expression profiles provide insights into the survival strategies in deep-sea mussel (Bathymodiolus platifrons) of different developmental stages

Background

Deep-sea mussels living in the cold seeps with enormous biomass act as the primary consumers. They are well adapted to the extreme environment where light is absent, and hydrogen sulfide, methane, and other hydrocarbon-rich fluid seepage occur. Despite previous studies on diversity, role, evolution, and symbiosis, the changing adaptation patterns during different developmental stages of the deep-sea mussels remain largely unknown.

Results

The deep-sea mussels (Bathymodiolus platifrons) of two developmental stages were collected from the cold seep during the ocean voyage. The gills, mantles, and adductor muscles of these mussels were used for the Illumina sequencing. A total of 135 Gb data were obtained, and subsequently, 46,376 unigenes were generated using de-novo assembly strategy. According to the gene expression analysis, amounts of genes were most actively expressed in the gills, especially genes involved in environmental information processing. Genes encoding Toll-like receptors and sulfate transporters were up-regulated in gills, indicating that the gill acts as both intermedium and protective screen in the deep-sea mussel. Lysosomal enzymes and solute carrier responsible for nutrients absorption were up-regulated in the older mussel, while genes related to toxin resistance and autophagy were up-regulated in the younger one, suggesting that the older mussel might be in a vigorous stage while the younger mussel was still paying efforts in survival and adaptation.

Conclusions

In general, our study suggested that the adaptation capacity might be formed gradually during the development of deep-sea mussels, in which the gill and the symbionts play essential roles.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08505-9.

The Partial Role of KLF4 and KLF5 in Gastrointestinal Tumors

Background

KLF4 and KLF5 are members of the KLF transcription factor family, which play an important role in many gastrointestinal tumors. To gain a deeper insight into its function and role, bioinformatics was used to analyze the function and role of KLF4 and KLF5 in gastrointestinal tumors.

Methods

Data were collected from several online databases. Gene Expression Profiling Interactive Analysis (GEPIA), UALCAN database analysis, Kaplan-Meier Plotter analysis, LOGpc system, the Pathology Atlas, and the STRING website were used to analyze the data. We download relevant data from TCGA and then perform GO enrichment and KEGG enrichment analysis. The effects of KLF5 on gastric cancer cell proliferation were measured by CCK-8 assay. The effect of KLF5 on the expression of CyclinD1 and MMP9 was detected by Western blot.

Results

KLF4 and KLF5 were differentially expressed in normal and tumor tissues of the gastrointestinal tract, and their differential expression is related to several genes or pathways. KEGG analysis showed that KLF5 was coexpressed with endocytosis-related genes. KLF5 promotes the proliferation of gastric cancer cells and the expression of metastasis-related molecules.

Conclusion

KLF4 and KLF5 are of great significance for developing gastrointestinal tumors and can be used as therapeutic targets.

Interplay of Nanoparticle Properties during Endocytosis

Nanoparticles (NPs) have been widely applied as drug carriers in drug delivery, due to their unique physical and structural properties. To achieve the drug delivery purpose, receptor-mediated endocytosis is a primary explored mechanism to internalize NPs into tumor cells. During the endocytosis process, properties of NPs, including size, shape, and surface functionality, play an important role in determining the final drug delivery efficacy. Many of these NP properties have been extensively explored individually. However, the multiple NP properties naturally interplay with each other in the endocytosis process to determine the internalization efficiency together. Therefore, it is significantly important to understand the interplay of different NP properties to improve the NP’s final delivery efficacy. In this review, we focus on the interplay of NPs properties on the endocytosis process to summarize the relevant experimental observations and physical mechanisms. Particularly, three different aspects are discussed in detail, including the interplay between size and shape; size and elasticity; shape and elasticity. We have summarized the most recent works and highlighted that building up systematic understandings for the complex interplay between NP properties can greatly help a better design of NP platforms for drug delivery.

Engineered EV-Mimetic Nanoparticles as Therapeutic Delivery Vehicles for High-Grade Serous Ovarian Cancer

Simple Summary

In this review, we begin with the role of natural extracellular vesicles (EVs) in high-grade serous ovarian cancer (HGSOC). Then, we narrow our focus on the advantages of using EV-mimetic nanoparticles as a delivery vehicle for RNAi therapy and other chemotherapeutics. Furthermore, we discuss the challenges of the clinical translation of engineering EV mimetic drug delivery systems and the promising directions of further development.

Abstract

High-grade serous ovarian cancer (HGSOC) is the most lethal gynecological malignancy among women. Several obstacles impede the early diagnosis and effective treatment options for ovarian cancer (OC) patients, which most importantly include the development of platinum-drug-resistant strains. Currently, extensive efforts are being put into the development of strategies capable of effectively circumventing the physical and biological barriers present in the peritoneal cavity of metastatic OC patients, representing a late stage of gastrointestinal and gynecological cancer with an extremely poor prognosis. Naturally occurring extracellular vesicles (EVs) have been shown to play a pivotal role in progression of OC and are now being harnessed as a delivery vehicle for cancer chemotherapeutics. However, there are limitations to their clinical application due to current challenges in their preparation techniques. Intriguingly, there is a recent drive towards the use of engineered synthetic EVs for the delivery of chemotherapeutics and RNA interference therapy (RNAi), as they show the promise of overcoming the obstacles in the treatment of OC patients. This review discusses the therapeutic application of EVs in OC and elucidates the potential use of engineered EV-mimetic nanoparticles as a delivery vehicle for RNAi therapy and other chemotherapeutics, which would potentially improve clinical outcomes of OC patients.

Microplastics and nanoplastics in the environment: Macroscopic transport and effects on creatures

Industrial progress has brought us an important polymer material, i.e. plastic. Because of mass production and use, and improper management and disposal, plastic pollution has become one of the most pivotal environmental issues in the world today. However, the current researches on microplastics/nanoplastics are mainly focused on individual aquatic, terrestrial and atmospheric environments, ignoring the fact that the natural environment is a whole. In this regard, the transport of microplastics/nanoplastics among the three environment compartments, including reciprocal contributions and inherent connections, and the impact of microplastics/nanoplastics on organisms living in multiple environments are research problems that we pay special attention to. Furthermore, this paper comprehensively reviews the transport and distribution of microplastics/nanoplastics in individual compartments and the toxicity of organisms, either alone or in combination with other pollutants. The properties of microplastics/nanoplastics, environment condition and the growth habit of organisms are critical to the transport, distribution and toxicity of microplastics/nanoplastics. These knowledge gaps need to be addressed urgently to improve cognition of the degree of plastic pollution and enhance our ability to deal with pollution. Meanwhile, it is hoped that the paper can provide a relatively complete theoretical knowledge system and multiple "leads" for future innovative ideas in this field.

Enhanced gene expression by a novel designed leucine zipper endosomolytic peptide

An endosomal trap is a major barrier in gene therapy. We have designed an endosomolytic peptide based on the leucine zipper sequence and characterized it both structurally and functionally. The results illustrated that leucine zipper endosomolytic peptide (LZEP) exhibited appreciable hemolysis of human red blood cells (hRBCs) at pH 5.0, but negligible hemolysis at pH 7.4. Calcein release experiment indicated that only at pH 5.0 but not at pH 7.4, LZEP was able to permeabilize hRBCs. LZEP revealed significant self-assembly as well as peptide induced α-helical structure at pH 5.0. Unlike at pH 5.0, LZEP failed to self-assemble and showed a random coil structure at pH 7.4. Transfection data depicted that lipoplexes modified with LZEP resulted in significantly higher gene expression as compared to lipoplexes without LZEP. Interestingly, the transfection efficacy of LZEP modified lipid nanoparticles reached the levels of Lipofectamine 2000 (LF 2000), without any cellular toxicity as observed by MTT assay. The results suggest a novel approach for designing endosomolytic peptides by employing the leucine zipper sequence and simultaneously the designed peptides could be utilized for enhancing gene delivery into mammalian cells.

Non-viral Gene Delivery Methods for Bone and Joints

Viral carrier transport efficiency of gene delivery is high, depending on the type of vector. However, viral delivery poses significant safety concerns such as inefficient/unpredictable reprogramming outcomes, genomic integration, as well as unwarranted immune responses and toxicity. Thus, non-viral gene delivery methods are more feasible for translation as these allow safer delivery of genes and can modulate gene expression transiently both in vivo, ex vivo, and in vitro. Based on current studies, the efficiency of these technologies appears to be more limited, but they are appealing for clinical translation. This review presents a summary of recent advancements in orthopedics, where primarily bone and joints from the musculoskeletal apparatus were targeted. In connective tissues, which are known to have a poor healing capacity, and have a relatively low cell-density, i.e., articular cartilage, bone, and the intervertebral disk (IVD) several approaches have recently been undertaken. We provide a brief overview of the existing technologies, using nano-spheres/engineered vesicles, lipofection, and in vivo electroporation. Here, delivery for microRNA (miRNA), and silencing RNA (siRNA) and DNA plasmids will be discussed. Recent studies will be summarized that aimed to improve regeneration of these tissues, involving the delivery of bone morphogenic proteins (BMPs), such as BMP2 for improvement of bone healing. For articular cartilage/osteochondral junction, non-viral methods concentrate on targeted delivery to chondrocytes or MSCs for tissue engineering-based approaches. For the IVD, growth factors such as GDF5 or GDF6 or developmental transcription factors such as Brachyury or FOXF1 seem to be of high clinical interest. However, the most efficient method of gene transfer is still elusive, as several preclinical studies have reported many different non-viral methods and clinical translation of these techniques still needs to be validated. Here we discuss the non-viral methods applied for bone and joint and propose methods that can be promising in clinical use.

An ATP synthase beta subunit is required for internalization of dsRNA into shrimp cells

Extracellular double-stranded RNA (dsRNA) is an important modulator in innate immunity in both vertebrates and invertebrates. In shrimp, extracellular dsRNA can trigger RNAi pathway and serves as antiviral defense mechanism. However, the mechanism of dsRNA internalization into the cells has not yet known in shrimp cells. This study identified candidate cell surface proteins from shrimp hepatopancreatic cells that could interact with dsRNA by a ligand blot assay. Among the candidate proteins, a cell-surface beta subunit of ATP synthase was shown to be capable of internalizing dsRNA into shrimp hepatopancreatic cells that could rapidly occur in just 1 min upon dsRNA challenge. Colocalization between dsRNA and ATP synthase beta subunit implied correlation between dsRNA and ATP synthase beta subunit during dsRNA internalization. Furthermore, dsRNA showed colocalization with Ras-related endocytic proteins, Rab5 and Rab7 indicating that dsRNA was internalized via the receptor-mediated endocytosis. For the above evidences as well as the reduction of dsRNA internalization by angiostatin and antibodies against ATP synthase beta subunit, we propose that dsRNA interacts with ATP synthase via a nucleotide binding site in the beta subunit prior to internalize dsRNA into cells.

Materials promoting viral gene delivery

Therapeutic viral gene delivery is an emerging technology which aims to correct genetic mutations by introducing new genetic information to cells either to correct a faulty gene or to initiate cell death in oncolytic treatments. In recent years, significant scientific progress has led to several clinical trials resulting in the approval of gene therapies for human treatment. However, successful therapies remain limited due to a number of challenges such as inefficient cell uptake, low transduction efficiency (TE), limited tropism, liver toxicity and immune response. To adress these issues and increase the number of available therapies, additives from a broad range of materials like polymers, peptides, lipids, nanoparticles, and small molecules have been applied so far. The scope of this review is to highlight these selected delivery systems from a materials perspective.

Endocytosis in cellular uptake of drug delivery vectors: Molecular aspects in drug development

Drug delivery vectors are widely applied to increase drug efficacy while reducing the side effects and potential toxicity of a drug. They allow for patient-tailored therapy, dose titration, and therapeutic drug monitoring. A major part of drug delivery systems makes use of large nanocarriers: liposomes or virus-like particles (VLPs). These systems allow for a relatively large amount of cargo with good stability of vectors, and they offer multiple options for targeting vectors in vivo. Here we discuss endocytic pathways that are available for drug delivery by large nanocarriers. We focus on molecular aspects of the process, including an overview of potential molecular targets for studies of drug delivery vectors and for future solutions allowing targeted drug delivery.

Silica-Based Gene Delivery Systems: From Design to Therapeutic Applications

Advances in gene therapy have been foreshadowing its potential for the treatment of a vast range of diseases involving genetic malfunctioning. However, its therapeutic efficiency and successful outcome are highly dependent on the development of the ideal gene delivery system. On that matter, silica-based vectors have diverted some attention from viral and other types of non-viral vectors due to their increased safety, easily modifiable structure and surface, high stability, and cost-effectiveness. The versatility of silane chemistry and the combination of silica with other materials, such as polymers, lipids, or inorganic particles, has resulted in the development of carriers with great loading capacities, ability to effectively protect and bind genetic material, targeted delivery, and stimuli-responsive release of cargos. Promising results have been obtained both in vitro and in vivo using these nanosystems as multifunctional platforms in different potential therapeutic areas, such as cancer or brain therapies, sometimes combined with imaging functions. Herein, the current advances in silica-based systems designed for gene therapy are reviewed, including their main properties, fabrication methods, surface modifications, and potential therapeutic applications.

Nanospheres Loaded with Curcumin Improve the Bioactivity of Umbilical Cord Blood-Mesenchymal Stem Cells via c-Src Activation During the Skin Wound Healing Process

Curcumin, a hydrophobic polyphenol derived from turmeric, has been used a food additive and as a herbal medicine for the treatment of various diseases, but the clinical application of curcumin is restricted by its poor aqueous solubility and its low permeability and bioavailability levels. In the present study, we investigate the functional role of a nanosphere loaded with curcumin (CN) in the promotion of the motility of human mesenchymal stem cells (MSCs) during the skin wound healing process. CN significantly increased the motility of umbilical cord blood (UCB)-MSCs and showed 10,000-fold greater migration efficacy than curcumin. CN stimulated the phosphorylation of c-Src and protein kinase C which are responsible for the distinctive activation of the MAPKs. Interestingly, CN significantly induced the expression levels of α-actinin-1, profilin-1 and filamentous-actin, as regulated by the phosphorylation of nuclear factor-kappa B during its promotion of cell migration. In a mouse skin excisional wound model, we found that transplantation of UCB-MSCs pre-treated with CN enhanced wound closure, granulation, and re-epithelialization at mouse skin wound sites. These results indicate that CN is a functional agent that promotes the mobilization of UCB-MSCs for cutaneous wound repair.

Enhanced Gene Delivery in Bacterial and Mammalian Cells Using PEGylated Calcium Doped Magnetic Nanograin

BACKGROUND

Beyond viral carriers which have been widely used in gene delivery, non-viral carriers can further improve the delivery process. However, the high cytotoxicity and low efficiency impedes the clinical application of non-viral systems. Therefore, in this work, we fabricated polyethylene glycol (PEG) coated, calcium doped magnetic nanograin (PEG/Ca(II)/Fe3O4) as a genome expression enhancer.

METHODS

Monodisperse magnetic nanograins (MNGs) with tunable size were synthesized by a solvothermal method. The citrate anions on the spherical surface of MNGs capture Ca2+ ions by an ion exchange process, which was followed by surface capping with PEG. The synthesized PEG/Ca(II)/Fe3O4 was characterized using Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) spectra, vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). MTT test was utilized to assess the toxicity of PEG/Ca(II)/Fe3O4. Real time qPCR was applied for quantification of gene expression.

RESULTS

DLS spectra and TEM images confirmed a thin layer of PEG on the nanocarrier surface. Shifting the zeta potential in the biological pH window from -23.9 mV (for Fe3O4) to ≈ +11 mV (for PEG/Ca(II)/Fe3O4) confirms the MNGs surface protonation. Cytotoxicity results show that cell viability and proliferation were not hindered in a wide range of nanocarrier concentrations and different incubation times.

CONCLUSION

PEGylated calcium doped magnetic nanograin enhanced PUC19 plasmid expression into E. Coli and GFP protein expression in HEK-293 T cells compared to control. A polymerase chain reaction of the NeoR test shows that the transformed plasmids are of high quality.

Biodistribution and biocompatibility of glycyrrhetinic acid and galactose-modified chitosan nanoparticles as a novel targeting vehicle for hepatocellular carcinoma

Aim: The dual-ligand glycyrrhetinic acid and galactose-modified chitosan nanoparticles were designed to further improve the targeting capability to hepatocellular carcinoma (HCC). Materials & methods: The dual-ligand glycyrrhetinic acid and galactose-modified chitosan nanoparticles were fabricated by using ionic gelation method and their characteristics have been measured. Furthermore, the biodistribution and biocompatibility of this targeting vehicle were investigated in vitro and in vivo, respectively. Results: The targeting vehicle was specifically internalized into hepatoma cells in vitro and accumulated into tumor tissue in vivo with high efficacy. Moreover, the vehicle did not induce inflammation reaction and affect morphologies and organ functions. Conclusion: The targeting accumulation in HCC tissue and great biocompatibility of the dual-ligand modified chitosan nanoparticles highlight the potential of delivering anticancer agents into HCC cells.

Polymeric siRNA gene delivery - transfection efficiency versus cytotoxicity

Within the field of gene therapy, there is a considerable need for the development of non-viral vectors that are able to compete with the efficiency obtained by viral vectors, while maintaining a good toxicity profile and not inducing an immune response within the body. While there have been many reports of possible polymeric delivery systems, few of these systems have been successful in the clinical setting due to toxicity, systemic instability or gene regulation inefficiency, predominantly due to poor endosomal escape and cytoplasmic release. The objective of this review is to provide an overview of previously published polymeric non-coding RNA and, to a lesser degree, oligo-DNA delivery systems with emphasis on their positive and negative attributes, in order to provide insight in the numerous hurdles that still limit the success of gene therapy.

Emergence of Nanoplastic in the Environment and Possible Impact on Human Health

On account of environmental concerns, the fate and adverse effects of plastics have attracted considerable interest in the past few years. Recent studies have indicated the potential for fragmentation of plastic materials into nanoparticles, i.e., "nanoplastics," and their possible accumulation in the environment. Nanoparticles can show markedly different chemical and physical properties than their bulk material form. Therefore possible risks and hazards to the environment need to be considered and addressed. However, the fate and effect of nanoplastics in the (aquatic) environment has so far been little explored. In this review, we aim to provide an overview of the literature on this emerging topic, with an emphasis on the reported impacts of nanoplastics on human health, including the challenges involved in detecting plastics in a biological environment. We first discuss the possible sources of nanoplastics and their fates and effects in the environment and then describe the possible entry routes of these particles into the human body, as well as their uptake mechanisms at the cellular level. Since the potential risks of environmental nanoplastics to humans have not yet been extensively studied, we focus on studies demonstrating cell responses induced by polystyrene nanoparticles. In particular, the influence of particle size and surface chemistry are discussed, in order to understand the possible risks of nanoplastics for humans and provide recommendations for future studies.

A new polymer-based approach for in vivo transfection in postnatal brain

BACKGROUND

Gene delivery within the central nervous system at postnatal age is one of the most challenging tasks in neuroscience and currently only a few effective methods are available.

COMPARISON WITH EXISTING METHODS

For postnatal central nervous system cells, viral approaches are commonly used for genetic engineering but they face several biosafety requirements for production and use making them less accessible to the community. Conversely, lipid-based methods are widely used in cell culture but face limitation in vivo mainly due to the inflammatory responses they induce. To this aspect, the use of a transgenic mouse line can represent a credible answer to the community working on rat models still requires an effective and successful solution to circumvent these difficulties.

NEW METHOD

We describe a new polymer-based gene delivery system allowing persistent and robust in vivo transfection with low DNA amount, reduced inflammation and high diffusion. The expression profile along the brain, the stability, the diffusion of the DNA together with the quantity of cells transfected were evaluated through in vivo approaches.

RESULTS

With a single low-volume injection, we targeted different cell types within the rat brain. We measured the diffusion rate ranging from 1 to 5 mm based on the injected volume, in the three-dimensions axis. Finally, we modified brain susceptibility to epileptic seizures using a specific knock-down of the neuronal specific potassium-chloride transporter 2.

CONCLUSIONS

This safe and easy system opens perspectives for non viral gene delivery in the rat brain with perspectives to study brain function in vivo.

Delivery of docetaxel using pH-sensitive liposomes based on D-α-tocopheryl poly(2-ethyl-2-oxazoline) succinate: Comparison with PEGylated liposomes

This study aimed to investigate the ability of the novel materials D-α-tocopheryl poly(2-ethyl-2-oxazoline) succinate (TPOS) to construct pH-sensitive liposomes. TPOS was initially synthesized and characterized by TLC, FTIR, and ¹H-NMR. The buffering capacity of polyethylene glycol- distearoyl phosphatidylethanolamine (PEG-DSPE) and TPOS was determined by acid-base titration, and TPOS displayed a slower downtrend and gentler slope of titration curve than PEG-DSPE within pH 7.4–5.0. Studies on the in vitro drug release demonstrated that TPOS modified docetaxel (DOC) liposomes (TPOS-DOC-L) had a slower drug-release rate at pH 7.4 similar to PEGylated-DOC liposomes (PEG-DOC-L), whereas the release rate reached approximately 86.92% ± 1.69% at pH 6.4. In vitro cellular uptake assays by microplate reader, and flow cytometry revealed that TPOS modified coumarin 6 liposomes (TPOS-C6-L) had stronger cellular uptake at pH 6.4 than that at pH 7.4 (P < 0.01). Conversely, for PEGylated C6 liposomes (PEG-C6-L) and conventional C6 liposomes (C6-L), very similar cellular uptakes were exhibited at different pH values. Confocal laser scanning microscopy images showed that PEG-C6-L and C6-L were mainly located in lysosomes. By contrast, TPOS-C6-L showed broader cytoplasmic release and distribution at 4 h. MTT assay showed that the cytotoxicity of TPOS-DOC-L was similar to that of PEG-DOC-L and conventional DOC liposomes (DOC-L) at the same DOC concentration and at pH 7.4, but was much lower than those at pH 6.4 after 48 h of incubation. The apoptosis of PEG-DOC-L and DOC-L had no remarkable improvement with decreased pH from 7.4 to 6.4. Meanwhile, TPOS-DOC-L significantly induced the apoptosis of HeLa cells with decreased pH. Therefore, TPOS can be a biomaterial for the construction of a pH-sensitive drug delivery system.

Mitochondrial DNA as an inflammatory mediator in cardiovascular diseases

Mitochondria play a central role in multiple cellular functions, including energy production, calcium homeostasis, and cell death. Currently, growing evidence indicates the vital roles of mitochondria in triggering and maintaining inflammation. Chronic inflammation without microbial infection — termed sterile inflammation — is strongly involved in the development of heart failure. Sterile inflammation is triggered by the activation of pattern recognition receptors (PRRs) that sense endogenous ligands called damage-associated molecular patterns (DAMPs). Mitochondria release multiple DAMPs including mitochondrial DNA, peptides, and lipids, which induce inflammation via the stimulation of multiple PRRs. Among the mitochondrial DAMPs, mitochondrial DNA (mtDNA) is currently highlighted as the DAMP that mediates the activation of multiple PRRs, including Toll-like receptor 9, Nod-like receptors, and cyclic GMP–AMP synthetase/stimulator of interferon gene pathways. These PRR signalling pathways, in turn, lead to the activation of nuclear factor-κB and interferon regulatory factor, which enhances the transcriptional activity of inflammatory cytokines and interferons, and induces the recruitment of inflammatory cells. As the heart is an organ comprising abundant mitochondria for its ATP consumption (needed to maintain constant cyclic contraction and relaxation), the generation of massive amounts of mitochondrial radical oxygen species and mitochondrial DAMPs are predicted to occur and promote cardiac inflammation. Here, we will focus on the role of mtDNA in cardiac inflammation and review the mechanism and pathological significance of mtDNA-induced inflammatory responses in cardiac diseases.

Pathways of cellular internalisation of liposomes delivered siRNA and effects on siRNA engagement with target mRNA and silencing in cancer cells

Design of an efficient delivery system is a generally recognised bottleneck in translation of siRNA technology into clinic. Despite research efforts, cellular processes that determine efficiency of siRNA silencing achieved by different delivery formulations remain unclear. Here, we investigated the mechanism(s) of cellular internalisation of a model siRNA-loaded liposome system in a correlation to the engagement of delivered siRNA with its target and consequent silencing by adopting siRNA molecular beacon technology. Probing of cellular internalisation pathways by a panel of pharmacological inhibitors indicated that clathrin-mediated (dynamin-dependent) endocytosis, macropinocytosis (dynamine independent), and cell membrane cholesterol dependent process(es) (clathrin and caveolea-independent) all play a role in the siRNA-liposomes internalization. The inhibition of either of these entry routes was, in general, mirrored by a reduction in the level of siRNA engagement with its target mRNA, as well as in a reduction of the target gene silencing. A dramatic increase in siRNA engagement with its target RNA was observed on disruption of endosomal membrane (by chloroquine), accompanied with an increased silencing. The work thus illustrates that employing molecular beacon siRNA technology one can start to assess the target RNA engagement - a stage between initial cellular internalization and final gene silencing of siRNA delivery systems.

Transcriptome-wide elucidation of liposomal formulations for anticancer drug delivery

Although widely used in chemotherapy, free doxorubicin (Dox) might enhance cell malignancy undesirably. Liposomal Dox (Doxlipo) has been clinically approved for the treatment of breast cancer due to reduced systematical toxicity and increased tumor targeting, yet the transcriptome-wide elucidation of the Doxlipo formulations remains elusive. To this end, we explored the impact of two Dox liposomal formulations, Doxlipo mainly containing hydrogenated soy phosphatidylcholine or 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, on the transcriptional pattern of MCF-7 cells. The two types of Dox liposomal formulations with different drug release kinetics were investigated to reveal the relationship between the formulation and tumor malignancy. Interestingly, we found that liposomal formulation significantly altered the transcriptional pattern of a wide range of genes. Under equivalent dosage of Dox, free Dox substantially changed the expression of ANK1, ACTA2, GPR87, GDF15, FZD6, and WNT4 in MCF-7 cells. Notably, free Dox induced much higher expression of ABCB1 and significantly enhanced the cell migration behavior in comparison with HSPC Doxlipo under a similar level of cytotoxicity. Finally, siRNA targeting GPR87 was codelivered with cationic Doxlipo to reduce the expression of malignancy-related genes. Our study, for the first time, provides an overview of the influence of formulation on the malignancy at transcriptional level and reveals the relationship between cytotoxicity and cell malignancy from the formulation aspect, offering valuable reference for the future formulation design for anticancer drug delivery.

Advances in the understanding of mitochondrial DNA as a pathogenic factor in inflammatory diseases

Mitochondrial DNA (mtDNA) has many similarities with bacterial DNA because of their shared common ancestry. Increasing evidence demonstrates mtDNA to be a potent danger signal that is recognised by the innate immune system and can directly modulate the inflammatory response. In humans, elevated circulating mtDNA is found in conditions with significant tissue injury such as trauma and sepsis and increasingly in chronic organ-specific and systemic illnesses such as steatohepatitis and systemic lupus erythematosus. In this review, we examine our current understanding of mtDNA-mediated inflammation and how the mechanisms regulating mitochondrial homeostasis and mtDNA release represent exciting and previously under-recognised important factors in many human inflammatory diseases, offering many new translational opportunities.

Targeted delivery of in situ PCR-amplified Sleeping Beauty transposon genes to cancer cells with lipid-based nanoparticle-like protocells

A Sleeping Beauty (SB) transposon system is made of a transposon plasmid (containing gene encoding a desired functional or therapeutic protein) and a transposase plasmid (encoding an enzyme capable of cutting and pasting the gene into the host cell genome). It is a kind of natural, nonviral gene delivery vehicle, which can achieve efficient genomic insertion, providing long-term transgenic expression. However, before the SB transposon system could play a role in promoting gene expression, it has to be delivered efficiently first across cell membrane and then into cell nuclei. Towards this end, we used a nanoparticle-like lipid-based protocell, a closed bilayer of the neutral lipids with the DNA encapsulated inside, to deliver the SB transposon system to cancer cells. The SB transposon system was amplified in situ inside the protocells by a polymerase chain reaction (PCR) process, realizing more efficient loading and delivery of the target gene. To reach a high transfection efficiency, we introduced two targeting moieties, folic acid (FA) as a cancer cell-targeting motif and Dexamethasone (DEX) as a nuclear localization signaling molecule, into the protocells. As a result, the FA enabled the modified targeting protocells to deliver the DNA into the cancer cells with an increased efficiency and the DEX promoted the DNA to translocate to cell nuclei, eventually leading to the increased chromosome insertion efficiency of the SB transposon. In vivo study strongly suggested that the transfection efficiency of FA-modified protocells in the tumor tissue was much higher than that in other tissues, which was consistent with the in vitro results. Our studies implied that with the targeting ligand modification, the protocells could be utilized as an efficient targeting gene carrier. Since the protocells were made of neutral lipids without cationic charges, the cytotoxicity of protocells was significantly lower than that of traditional cationic gene carriers such as cationic liposomes and polyethylenimine, enabling the protocells to be employed in a wider dosage range in gene therapy. Our work shows that the protocells are a promising gene carrier for future clinical applications.

Delivery of nucleic acids for cancer gene therapy: overcoming extra- and intra-cellular barriers

The therapeutic potential of cancer gene therapy has been limited by the difficulty of delivering genetic material to target sites. Various biological and molecular barriers exist which need to be overcome before effective nonviral delivery systems can be applied successfully in oncology. Herein, various barriers are described and strategies to circumvent such obstacles are discussed, considering both the extracellular and intracellular setting. Development of multifunctional delivery systems holds much promise for the progression of gene delivery, and a growing body of evidence supports this approach involving rational design of vectors, with a unique molecular architecture. In addition, the potential application of composite gene delivery platforms is highlighted which may provide an alternative delivery strategy to traditional systemic administration.

Comparison of Different Electroporation Parameters on Transfection Efficiency of Sheep Testicular Cells

OBJECTIVE

Electroporation can be a highly efficient method for introducing the foreign genetic materials into the targeted cells for transient and/or permanent genetic modification. Considering the application of this technique as a very efficient method for drug, oligonucleotide, antibody and plasmid delivery for clinical applications and production of transgenic animals, the present study aimed to optimize the transfection efficiency of sheep testicular cells including spermatogonial stem cells (SSCs) via electroporation.

MATERIALS AND METHODS

This study is an experimental research conducted in Biotechnology Research Center (Avicenna Research Institute, Tehran, Iran) from September 2013 to March 2014. Following isolation and propagation of one-month lamb testicular cells (SSCs and somatic testicular cells including; Sertoli, Leydig, and myoid cells), the effect of different electroporation parameters including total voltages (280, 320, and 350 V), burst durations (10, 8, and 5 milliseconds), burst modes (single or double) and addition of dimethyl sulfoxide (DMSO) were evaluated on transfection efficiency, viability rate and mean fluorescent intensity (MFI) of sheep testicular cells.

RESULTS

The most transfection efficiency was obtained in 320 V/8 milliseconds/single burst group in transduction medium with and without DMSO. There was a significantly inverse correlation between transfection efficiency with application of both following parameters: addition of DMSO and double burst. After transfection, the highest and lowest viability rates of testicular cells were demonstrated in 320 V/8 milliseconds with transduction medium without DMSO and 350 V/5 milliseconds in medium containing DMSO. Ad- dition of DMSO to transduction medium in all groups significantly decreased the viability rate. The comparison of gene expression indicated that Sertoli and SSCs had the most fluorescence intensity in 320 V/double burst/DMSO positive. However, myoid and Leydig cells showed the maximum expression in 320 V/single burst and/or 350 V/double burst/ DMSO positive.

CONCLUSION

We optimized the electroporation method for transfection of sheep testicular cells and recommended the application of 320 V/8 milliseconds/single pulse/DMSO negative for transduction of plasmid vector into these cells. Among testicular cells, the most external gene expression was demonstrated in SSC population.

Delivery of cancer therapeutics to extracellular and intracellular targets: Determinants, barriers, challenges and opportunities

Advances in molecular medicine have led to identification of worthy cellular and molecular targets located in extracellular and intracellular compartments. Effectiveness of cancer therapeutics is limited in part by inadequate delivery and transport in tumor interstitium. Parts I and II of this report give an overview on the kinetic processes in delivering therapeutics to their intended targets, the transport barriers in tumor microenvironment and extracellular matrix (TME/ECM), and the experimental approaches to overcome such barriers. Part III discusses new concepts and findings concerning nanoparticle-biocorona complex, including the effects of TME/ECM. Part IV outlines the challenges in animal-to-human translation of cancer nanotherapeutics. Part V provides an overview of the background, current status, and the roles of TME/ECM in immune checkpoint inhibition therapy, the newest cancer treatment modality. Part VI outlines the development and use of multiscale computational modeling to capture the unavoidable tumor heterogeneities, the multiple nonlinear kinetic processes including interstitial and transvascular transport and interactions between cancer therapeutics and TME/ECM, in order to predict the in vivo tumor spatiokinetics of a therapeutic based on experimental in vitro biointerfacial interaction data. Part VII provides perspectives on translational research using quantitative systems pharmacology approaches.

Gene Therapy in Heart Failure

Heart failure is a significant burden to the global healthcare system and represents an underserved market for new pharmacologic strategies, especially therapies which can address root cause myocyte dysfunction. Modern drugs, surgeries, and state-of-the-art interventions are costly and do not improve survival outcome measures. Gene therapy is an attractive strategy, whereby selected gene targets and their associated regulatory mechanisms can be permanently managed therapeutically in a single treatment. This in theory could be sustainable for the patient's life. Despite the promise, however, gene therapy has numerous challenges that must be addressed together as a treatment plan comprising these key elements: myocyte physiologic target validation, gene target manipulation strategy, vector selection for the correct level of manipulation, and carefully utilizing an efficient delivery route that can be implemented in the clinic to efficiently transfer the therapy within safety limits. This chapter summarizes the key developments in cardiac gene therapy from the perspective of understanding each of these components of the treatment plan. The latest pharmacologic gene targets, gene therapy vectors, delivery routes, and strategies are reviewed.

Towards Targeted Delivery Systems: Ligand Conjugation Strategies for mRNA Nanoparticle Tumor Vaccines

The use of nanoparticles encapsulating messenger RNA (mRNA) as a vaccine has recently attracted much attention because of encouraging results achieved in many nonviral genetic antitumor vaccination studies. Notably, in all of these studies, mRNA nanoparticles are passively targeted to dendritic cells (DCs) through careful selection of vaccination sites. Hence, DC-targeted mRNA nanoparticle vaccines may be an imminent next step forward. In this brief report, we will discuss established conjugation strategies that have been successfully applied to both polymeric and liposomal gene delivery systems. We will also briefly describe promising DC surface receptors amenable for targeting mRNA nanoparticles. Practicable conjugation strategies and receptors reviewed in this paper will provide a convenient reference to facilitate future development of targeted mRNA nanoparticle vaccine.

Cardiac gene therapy: Recent advances and future directions

Gene therapy has the potential to serve as an adaptable platform technology for treating various diseases. Cardiovascular disease is a major cause of mortality in the developed world and genetic modification is steadily becoming a more plausible method to repair and regenerate heart tissue. Recently, new gene targets to treat cardiovascular disease have been identified and developed into therapies that have shown promise in animal models. Some of these therapies have advanced to clinical testing. Despite these recent successes, several barriers must be overcome for gene therapy to become a widely used treatment of cardiovascular diseases. In this review, we evaluate specific genetic targets that can be exploited to treat cardiovascular diseases, list the important delivery barriers for the gene carriers, assess the most promising methods of delivering the genetic information, and discuss the current status of clinical trials involving gene therapies targeted to the heart.

Nanoparticle-mediated delivery of siRNA for effective lung cancer therapy

Lung cancer is one of the most lethal diseases worldwide, and the survival rate is less than 15% even after the treatment. Unfortunately, chemotherapeutic treatments for lung cancer are accompanied by severe side effects, lack of selectivity and multidrug resistance. In order to overcome the limitations of conventional chemotherapy, nanoparticle-mediated RNA interference drugs represent a potential new approach due to selective silencing effect of oncogenes and multidrug resistance related genes. In this review, we provide recent advancements on nanoparticle-mediated siRNA delivery strategies including lipid system, polymeric system and rigid nanoparticles for lung cancer therapies. Importantly, codelivery of siRNA with conventional anticancer drugs and recent theranostic agents that offer great potential for lung cancer therapy is covered.

Stimuli-responsive liposomes for the delivery of nucleic acid therapeutics

Nucleic acid therapeutics (NATs) are valuable tools in the modulation of gene expression in a highly specific manner. So far, NATs have been actively pursued in both pre-clinical and clinical studies to treat diseases such as cancer, infectious and inflammatory diseases. However, the clinical application of NATs remains a considerable challenge owing to their limited cellular uptake, low biological stability, off-target effect, and unfavorable pharmacokinetics. One concept to address these issues is to deliver NATs within stimuli-responsive liposomes, which release their contents of NATs upon encountering environmental changes such as temperature, pH, and ion strength. In this case, before reaching the targeted tissue/organ, NATs are protected from degradation by enzymes and immune system. Once at the area of interest, localized and targeted delivery can be achieved with minimal influence to other parts of the body. Here, we discuss the latest developments and existing challenges in this field.

FROM THE CLINICAL EDITOR

Nucleic acid therapeutics have been shown to enhance or eliminate specific gene expression in experimental research. Unfortunately, clinical applications have so far not been realized due to problems of easy degradation and possible toxicity. The use of nanosized carriers such as liposomes to deliver nucleic acids is one solution to overcome these problems. In this review article the authors describe and discuss the potentials of various trigger-responsive "smart" liposomes, with a view to help other researchers to design better liposomal nucleic acid delivery systems.

Superior cell penetration by a rigid and anisotropic synthetic protein

Molecules with structural anisotropy and rigidity, such as asbestos, demonstrate high cell-penetrating activity but also high toxicity. Here we synthesize a biodegradable, rigid, and fibrous artificial protein, CCPC 140, as a potential vehicle for cellular delivery. CCPC 140 penetrated 100% of cells tested in vitro, even at a concentration of 3.1 nM-superior to previously reported cell-penetrating peptides. The effects of cell-strain-dependency and aspect ratio on the cell-penetrating activity of CCPC 140 were also investigated.

Membrane lipid rafts, master regulators of hematopoietic stem cell retention in bone marrow and their trafficking

Cell outer membranes contain glycosphingolipids and protein receptors, which are integrated into glycoprotein microdomains, known as lipid rafts, which float freely in the membrane bilayer. These structures have an important role in assembling signaling molecules (e.g., Rac-1, RhoH and Lyn) together with surface receptors, such as the CXCR4 receptor for α-chemokine stromal-derived factor-1, the α4β1-integrin receptor (VLA-4) for vascular cell adhesion molecule-1 and the c-kit receptor for stem cell factor, which together regulate several aspects of hematopoietic stem/progenitor cell (HSPC) biology. Here, we discuss the role of lipid raft integrity in the retention and quiescence of normal HSPCs in bone marrow niches as well as in regulating HSPC mobilization and homing. We will also discuss the pathological consequences of the defect in lipid raft integrity seen in paroxysmal nocturnal hemoglobinuria and the emerging evidence for the involvement of lipid rafts in hematological malignancies.

Hyaluronic acid controls the uptake pathway and intracellular trafficking of an octaarginine-modified gene vector in CD44 positive- and CD44 negative-cells

The cellular uptake pathway for a gene vector is an important factor in transgene expression. We previously constructed an original gene vector, multifunctional envelope-type nano device (MEND). The use of octaarginine (R8), a cell-penetrating peptide dramatically enhanced the transfection activity of the MEND since efficient cellular uptake via macropinocytosis, while the R8 should overcome its poor cell selectivity. Here we prepared an R8-MEND equipped with GALA (a peptide for endosomal escape) (R8/GALA-MEND) coated with hyaluronic acid (HA) (HA-R8/GALA-MEND), a natural ligand for cancer cells overexpressing CD44. We investigated the cellular uptake pathway of the HA-R8/GALA-MEND and the R8/GALA-MEND using HCT116 cells overexpressing CD44. Both carriers were taken up by cells mainly via macropinocytosis, whereas only the HA-R8/GALA-MEND was partially internalized into cells via a CD44-mediated pathway. Investigation of transgene expression showed that the HA-R8/GALA-MEND had a high transfection activity in HCT116 cells via both macropinocytotic and CD44-mediated pathways. On the other hand, the value for the HA-R8/GALA-MEND was significantly decreased compared with the value for the R8/GALA-MEND in NIH3T3 cells (CD44-negative cells). These findings indicate that the HA-coating controls the intracellular pathway for R8-modified nanocarriers, and that a CD44-mediated pathway is an important route for transgene expression.

Elucidating the role of free polycationic chains in polycation gene carriers by free chains of polyethylenimine or N,N,N-trimethyl chitosan plus a certain polyplex

Polycations as gene carriers have attracted considerable attention over the past decade. Generally, polyplexes between polycations and deoxyribonucleic acid (DNA) are formed at low N/P ratios (the ratios of the numbers of nitrogen atoms in a polycation to the numbers of phosphorus atoms in DNA), but high transfection efficiency can only be obtained at much higher N/P ratios. Thus, many polycationic chains are still free in solution. In this study, we investigated the detailed functions of free polyethylenimine chains (PEI-F) and free N,N,N-trimethyl chitosan chains (TMC-F) using the same polyplex, ie, TMC polyplex (TMC-P), which has high stability in Dulbecco’s Modified Eagle’s Medium (DMEM). Meanwhile, PEI polyplex (PEI-P)/PEI-F was also evaluated rather than PEI-P/TMC-F because the stability of PEI-P is low in DMEM and, in the latter case, the TMC-F may replace the bound PEI chain in PEI-P to form TMC-P. The transfection results show that both TMC-F and PEI-F can significantly increase the transfection efficiency of TMC-P; however, PEI-F can upregulate the gene expression of TMC-P more efficiently than TMC-F. Further investigations on the endocytosis and intracellular trafficking show that PEI-P/PEI-F, TMC-P/PEI-F, and TMC-P/TMC-F exhibit similar cellular uptake efficiency. However, by shutting down the clathrin-mediated endocytosis or vacuolar proton pump, the transfection efficiency decreases in the order of PEI-P/PEI-F > TMC-P/PEI-F > TMC-P/TMC-F. These findings indicate that PEI-F and TMC-F may promote the transfection efficiency of the polyplex by affecting its cellular uptake pathway and intracellular trafficking.

Antitumor effect of iRGD-modified liposomes containing conjugated linoleic acid-paclitaxel (CLA-PTX) on B16-F10 melanoma

In the present study, we prepared a novel delivery system of iRGD (CRGDK/RGPD/EC)-modified sterically stabilized liposomes (SSLs) containing conjugated linoleic acid–paclitaxel (CLA-PTX). The anti-tumor effect of iRGD-SSL-CLA-PTX was investigated on B16-F10 melanoma in vitro and in vivo. The in vitro targeting effect of iRGD-modified SSLs was investigated in a real-time confocal microscopic analysis experiment. An endocytosis-inhibition assay was used to evaluate the endocytosis pathways of the iRGD-modified SSLs. In addition, the in vitro cellular uptake and in vitro cytotoxicity of iRGD-SSL-CLA-PTX were evaluated in B16-F10 melanoma cells. In vivo biodistribution and in vivo antitumor effects of iRGD-SSL-CLA-PTX were investigated in B16-F10 tumor-bearing mice. The induction of apoptosis by iRGD-SSL-CLA-PTX was evaluated in tumor-tissue sections. Real-time confocal microscopic analysis results indicated that the iRGD-modified SSLs internalized into B16-F10 cells faster than SSLs. The identified endocytosis pathway of iRGD-modified SSLs indicated that energy- and lipid raft-mediated endocytosis played a key role in the liposomes’ cellular uptake. The results of the cellular uptake experiment indicated that the increased cellular uptake of CLA-PTX in the iRGD-SSL-CLA-PTX-treated group was 1.9-, 2.4-, or 2.1-fold compared with that in the CLA-PTX group after a 2-, 4-, or 6-hour incubation, respectively. In the biodistribution test, the CLA-PTX level in tumor tissues from iRGD-SSL-CLA-PTX-treated mice at 1 hour (1.84±0.17 μg/g) and 4 hours (1.17±0.28 μg/g) was 2.3- and 2.0-fold higher than that of CLA-PTX solution at 1 hour (0.79±0.06 μg/g) and 4 hours (0.58±0.04 μg/g). The value of the area under the curve for the first 24 hours in the tumors of iRGD-SSL-CLA-PTX-treated mice was significantly higher than that in the SSL-CLA-PTX and CLA-PTX solution-treated groups (P<0.01). The in vivo antitumor results indicated that iRGD-SSL-CLA-PTX significantly inhibited the growth of B16-F10 tumors compared with the SSL-CLA-PTX or CLA-PTX solution-treatment groups (P<0.01). The results of tumor-cell apoptosis showed that tumors from the iRGD-SSL-CLA-PTX-treated group exhibited more advanced cell apoptosis compared with the control, CLA-PTX solution-, and SSL-CLA-PTX-treated groups. In conclusion, the antitumor effect of iRGD-SSL-CLA-PTX was confirmed on B16-F10 melanoma in vitro and in vivo.

Fast and efficient multitransgenic modification of human pluripotent stem cells

Human pluripotent stem cells (hPSCs) represent a prime cell source for pharmacological research and regenerative therapies because of their extensive expansion potential and their ability to differentiate into essentially all somatic lineages in vitro. Improved methods to stably introduce multiple transgenes into hPSCs will promote, for example, their preclinical testing by facilitating lineage differentiation and purification in vitro and the subsequent in vivo monitoring of respective progenies after their transplantation into relevant animal models. To date, the establishment of stable transgenic hPSC lines is still laborious and time-consuming. Current limitations include the low transfection efficiency of hPSCs via nonviral methods, the inefficient recovery of genetically engineered clones, and the silencing of transgene expression. Here we describe a fast, electroporation-based method for the generation of multitransgenic hPSC lines by overcoming the need for any preadaptation of conventional hPSC cultures to feeder-free conditions before genetic manipulation. We further show that the selection for a single antibiotic resistance marker encoded on one plasmid allowed for the stable genomic (co-)integration of up to two additional, independent expression plasmids. The method thereby enables the straightforward, nonviral generation of valuable multitransgenic hPSC lines in a single step. Practical applicability of the method is demonstrated for antibiotic-based lineage enrichment in vitro and for sodium iodide symporter transgene-based in situ cell imaging after intramyocardial cell infusion into explanted pig hearts.

Dynamic measurements of membrane insertion potential of synthetic cell penetrating peptides

Cell penetrating peptides (CPPs) have been established as excellent candidates for mediating drug delivery into cells. When designing synthetic CPPs for drug delivery applications, it is important to understand their ability to penetrate the cell membrane. In this paper, anionic or zwitterionic phospholipid monolayers at the air-water interface are used as model cell membranes to monitor the membrane insertion potential of synthetic CPPs. The insertion potential of CPPs having different cationic and hydrophobic amino acids were recorded using a Langmuir monolayer approach that records peptide adsorption to model membranes. Fluorescence microscopy was used to visualize alterations in phospholipid packing due to peptide insertion. All CPPs had the highest penetration potential in the presence of anionic phospholipids. In addition, two of three amphiphilic CPPs inserted into zwitterionic phospholipids, but none of the hydrophilic CPPs did. All the CPPs studied induced disruptions in phospholipid packing and domain morphology, which were most pronounced for amphiphilic CPPs. Overall, small changes to amino acids and peptide sequences resulted in dramatically different insertion potentials and membrane reorganization. Designers of synthetic CPPs for efficient intracellular drug delivery should consider small nuances in CPP electrostatic and hydrophobic properties.

Nanoparticle systems as tools to improve drug delivery and therapeutic efficacy

Nanoparticle-based drug delivery systems are appealing because, among other properties, they are easily manufactured and have the capacity to encapsulate a wide variety of drugs, many of which are not directly miscible with water. This review classifies nanoparticles into three broad categories based upon material composition: bio-inspired systems, synthetic systems, and inorganic systems. Each has distinct properties suitable for drug delivery applications, including their structure, composition, and pharmacokinetics (including clearance and uptake mechanisms), making each uniquely suitable for certain types of drugs. Furthermore, nanoparticles can be customized, making them ideal for a variety of applications. Advantages and disadvantages of the different systems are discussed. Strategies for improving nanoparticle efficacy include adding targeting agents on the nanoparticle surface, altering the degradation profile to control drug release, or PEGylating the surface to increase circulation times and reduce immediate clearance by the kidneys. The future of nanoparticle systems seems to be focused on further improving overall patient outcome by increasing delivery accuracy to the target area.

Transmembrane routes of cationic liposome-mediated gene delivery using human throat epidermis cancer cells

For studying the mechanism of cationic liposome-mediated transmembrane routes for gene delivery, various inhibitors of endocytosis were used to treat human throat epidermis cancer cells, Hep-2, before transfection with Lipofectamine 2000/pGFP-N2 or Lipofectamine 2000/pGL3. To eliminate the effect of inhibitor toxicity on transfection, the RLU/survival rate was used to represent the transfection efficiency. Chlorpromazine and wortmannin, clathrin inhibitors, decreased transfection efficiency by 44 % (100 μM) and 31 % (100 nM), respectively. At the same time, genistein, a caveolin inhibitor, decreased it by 30 % (200 μM). Thus combined transmembrane routes through the clathrin and caveolae-mediated pathways were major mechanisms of cell uptake for the cationic liposome-mediated gene delivery. After entering the cells, microtubules played an important role on gene delivery as vinblastine, a microtubulin inhibitor, could reduce transfection efficiency by 41 % (200 nM).