Protamine/DNA/Niosome Ternary Nonviral Vectors for Gene Delivery to the Retina: The Role of Protamine

Comparative analysis of lipid-peptide nanoparticles prepared via microfluidics, reverse phase evaporation, and ouzo techniques for efficient plasmid DNA delivery

In the current "era of lipid carriers," numerous strategies have been developed to manufacture lipid nanoparticles (LNPs). Nevertheless, the potential impact of various preparation methods on the characteristics, use, and/or stability of these LNPs remains unclear. In this work, we attempted to compare the effects of three different preparation methods: microfluidics (MF), reverse phase evaporation (RV), and ouzo (OZ) on lipid-peptide NPs (LPNPs) as plasmid DNA delivery carriers. These LPNPs had the same components, namely DOTMA cationic lipid, DSPC, cholesterol, and protamine. Subsequently, we compared the LPNPs in terms of their physicochemical features, functionality as gene delivery vehicles in two distinct cell lines (NT2 and D1-MSCs), and finally, their storage stability over a six-month period. It was clear that all three LPNP formulations worked to deliver EGFP-pDNA while keeping cells alive, and their physicochemical stability was high for 6 months. However, the preparation technique had a significant impact on their physicochemical characteristics. The MF produced LPNPs with a lesser size, polydispersity index, and zeta potential than the other synthesis methods. Additionally, their DNA entrapment efficiency, cell viability, and functional stability profiles were generally superior. These findings provide new insights for comparing different manufacturing methods to create LPNPs with the desired characteristics for effective and safe gene delivery.

Engineering aspects of lipid-based delivery systems: In vivo gene delivery, safety criteria, and translation strategies

Defects in the genome cause genetic diseases and can be treated with gene therapy. Due to the limitations encountered in gene delivery, lipid-based supramolecular colloidal materials have emerged as promising gene carrier systems. In their non-functionalized form, lipid nanoparticles often demonstrate lower transgene expression efficiency, leading to suboptimal therapeutic outcomes, specifically through reduced percentages of cells expressing the transgene. Due to chemically active substituents, the engineering of delivery systems for genetic drugs with specific chemical ligands steps forward as an innovative strategy to tackle the drawbacks and enhance their therapeutic efficacy. Despite intense investigations into functionalization strategies, the clinical outcome of such therapies still needs to be improved. Here, we highlight and comprehensively review engineering aspects for functionalizing lipid-based delivery systems and their therapeutic efficacy for developing novel genetic cargoes to provide a full snapshot of the translation from the bench to the clinics. We outline existing challenges in the delivery and internalization processes and narrate recent advances in the functionalization of lipid-based delivery systems for nucleic acids to enhance their therapeutic efficacy and safety. Moreover, we address clinical trials using these vectors to expand their clinical use and principal safety concerns.

Stability of polymeric cationic niosomes and their plasmid DNA-based complexes as gene delivery carriers

This study aims to explore the stability of lipo-polymeric niosomes/niosome-based pCMS-EGFP complexes under different storage temperatures (25 °C, 4 °C, and -20 °C). To date, the question of nucleic acid-complex stability is one of the most vital issues in gene delivery applications. The need for stable vaccines during the COVID-19 pandemic has merely highlighted it. In the case of niosomes as gene carriers, the scientific literature still lacks comprehensive stability studies. In this study, the physicochemical features of niosomes/nioplexes in terms of size, surface charge, and polydispersity index (PDI), along with transfection efficiency, and cytotoxicity in NT2 cells were evaluated for 8 weeks. Compared to day 0, the physicochemical features of the niosomes stored at 25 °C and -20 °C changed dramatically in terms of size, zeta potential, and PDI, while remaining in reasonable values when stored at 4 °C. However, niosomes and nioplexes stored at 4 °C and -20 °C showed nearly stable transfection efficiency values, yet an obvious decrease at 25 °C. This article provides a proof of concept into the stability of polymeric cationic niosomes and their nioplexes as promising gene delivery vehicles. Moreover, it highlights the practical possibility of storing nioplexes at 4 °C for up to 2 months, as an alternative to niosomes, for gene delivery purposes.

Trends in Formulation Approaches for Sustained Drug Delivery to the Posterior Segment of the Eye

The eye, an intricate organ comprising physical and physiological barriers, poses a significant challenge for ophthalmic physicians seeking to treat serious ocular diseases affecting the posterior segment, such as age-related macular degeneration (AMD) and diabetic retinopathy (DR). Despite extensive efforts, the delivery of therapeutic drugs to the rear part of the eye remains an unresolved issue. This comprehensive review delves into conventional and innovative formulation strategies for drug delivery to the posterior segment of the eye. By utilizing alternative nanoformulation approaches such as liposomes, nanoparticles, and microneedle patches, researchers and clinicians can overcome the limitations of conventional eye drops and achieve more effective drug delivery to the posterior segment of the eye. These innovative strategies offer improved drug penetration, prolonged residence time, and controlled release, enhancing therapeutic outcomes for ocular diseases. Moreover, this article explores recently approved delivery systems that leverage diverse polymer technologies, such as chitosan and hyaluronic acid, to regulate drug-controlled release over an extended period. By offering a comprehensive understanding of the available formulation strategies, this review aims to empower researchers and clinicians in their pursuit of developing highly effective treatments for posterior-segment ocular diseases.

Exploring the use of niosomes in cosmetics for efficient dermal drug delivery

Dermal drug delivery has emerged as a promising alternative to traditional methods of drug administration due to its non-invasive nature and ease of use. However, the stratum corneum, the outermost layer of the skin, presents a significant barrier to drug penetration. Niosomes, self-assembled vesicular structures composed of nonionic surfactants and cholesterol, have been extensively investigated as a means of overcoming this barrier and improving the efficacy of dermal drug delivery. This review summarizes the current state of research on the use of niosomes in dermal drug delivery in cosmetics, with a particular focus on their formulation, characterization, and application in the delivery of various drug classes. The review highlights the advantages of niosomes over conventional drug delivery methods, including improved solubility and stability of drugs, controlled release, and enhanced skin permeation. The review also discusses the challenges associated with niosome-based drug delivery, such as their complex formulation and optimization, and the need for further studies on their long-term safety and toxicity.

Long-term biophysical stability of nanodiamonds combined with lipid nanocarriers for non-viral gene delivery to the retina

Nanodiamonds were combined with niosome, and resulting formulations were named as nanodiasomes, which were evaluated in terms of physicochemical features, cellular internalization, cell viability and transfection efficiency both in in vitro and in in vivo conditions. Such parameters were analyzed at 4 and 25 ^°C, and at 15 and 30 days after their elaboration. Nanodiasomes showed a particle size of 128 nm that was maintained over time inside the ±10% of deviation, unless after 30 days of storage at 25°C. Something similar occurred with the initial zeta potential value, 35.2 mV, being both formulations more stable at 4°C. The incorporation of nanodiamonds into niosomes resulted in a 4-fold increase of transfection efficiency that was maintained over time at 4 and 25°C. In vivo studies reported high transgene expression of nanodiasomes after subretinal and intravitreal administration in mice, when injected freshly prepared and after 30 days of storage at 4°C.

Ocular Delivery of Therapeutic Proteins: A Review

Therapeutic proteins, including monoclonal antibodies, single chain variable fragment (ScFv), crystallizable fragment (Fc), and fragment antigen binding (Fab), have accounted for one-third of all drugs on the world market. In particular, these medicines have been widely used in ocular therapies in the treatment of various diseases, such as age-related macular degeneration, corneal neovascularization, diabetic retinopathy, and retinal vein occlusion. However, the formulation of these biomacromolecules is challenging due to their high molecular weight, complex structure, instability, short half-life, enzymatic degradation, and immunogenicity, which leads to the failure of therapies. Various efforts have been made to overcome the ocular barriers, providing effective delivery of therapeutic proteins, such as altering the protein structure or including it in new delivery systems. These strategies are not only cost-effective and beneficial to patients but have also been shown to allow for fewer drug side effects. In this review, we discuss several factors that affect the design of formulations and the delivery of therapeutic proteins to ocular tissues, such as the use of injectable micro/nanocarriers, hydrogels, implants, iontophoresis, cell-based therapy, and combination techniques. In addition, other approaches are briefly discussed, related to the structural modification of these proteins, improving their bioavailability in the posterior segments of the eye without affecting their stability. Future research should be conducted toward the development of more effective, stable, noninvasive, and cost-effective formulations for the ocular delivery of therapeutic proteins. In addition, more insights into preclinical to clinical translation are needed.

mRNA vaccines in the prevention and treatment of diseases

Messenger ribonucleic acid (mRNA) vaccines made their successful public debut in the effort against the COVID-19 outbreak starting in late 2019, although the history of mRNA vaccines can be traced back decades. This review provides an overview to discuss the historical course and present situation of mRNA vaccine development in addition to some basic concepts that underly mRNA vaccines. We discuss the general preparation and manufacturing of mRNA vaccines and also discuss the scientific advances in the in vivo delivery system and evaluate popular approaches (i.e., lipid nanoparticle and protamine) in detail. Next, we highlight the clinical value of mRNA vaccines as potent candidates for therapeutic treatment and discuss clinical progress in the treatment of cancer and coronavirus disease 2019. Data suggest that mRNA vaccines, with several prominent advantages, have achieved encouraging results and increasing attention due to tremendous potential in disease management. Finally, we suggest some potential directions worthy of further investigation and optimization. In addition to basic research, studies that help to facilitate storage and transportation will be indispensable for practical applications.

Surface Modification of Lipid-Based Nanoparticles

There is a growing interest in the development of lipid-based nanocarriers for multiple purposes, including the recent increase of these nanocarriers as vaccine components during the COVID-19 pandemic. The number of studies that involve the surface modification of nanocarriers to improve their performance (increase the delivery of a therapeutic to its target site with less off-site accumulation) is enormous. The present review aims to provide an overview of various methods associated with lipid nanoparticle grafting, including techniques used to separate grafted nanoparticles from unbound ligands or to characterize grafted nanoparticles. We also provide a critical perspective on the usefulness and true impact of these modifications on overcoming different biological barriers, with our prediction on what to expect in the near future in this field.

Treating Pulmonary Fibrosis with Non-Viral Gene Therapy: From Bench to Bedside

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease characterized by irreversible lung scarring, which achieves almost 80% five-year mortality rate. Undeniably, commercially available pharmaceuticals, such as pirfenidone and nintedanib, exhibit certain effects on improving the well-being of IPF patients, but the stubbornly high mortality still indicates a great urgency of developing superior therapeutics against this devastating disease. As an emerging strategy, gene therapy brings hope for the treatment of IPF by precisely regulating the expression of specific genes. However, traditional administration approaches based on viruses severely restrict the clinical application of gene therapy. Nowadays, non-viral vectors are raised as potential strategies for in vivo gene delivery, attributed to their low immunogenicity and excellent biocompatibility. Herein, we highlight a variety of non-viral vectors, such as liposomes, polymers, and proteins/peptides, which are employed in the treatment of IPF. By respectively clarifying the strengths and weaknesses of the above candidates, we would like to summarize the requisite features of vectors for PF gene therapy and provide novel perspectives on design-decisions of the subsequent vectors, hoping to accelerate the bench-to-bedside pace of non-viral gene therapy for IPF in clinical setting.

A ratiometric fluorescence strategy based on polyethyleneimine surface-modified carbon dots and Eosin Y for the ultrasensitive determination of protamine and trypsin

A ratiometric fluorescent nanoprobe for protamine and trypsin detection with excellent biocompatibility and high sensitivity was successfully constructed based on CDs-PEI and Eosin Y.

Sphingolipid extracts enhance gene delivery of cationic lipid vesicles into retina and brain

The aim was to evaluate relevant biophysic processes related to the physicochemical features and gene transfection mechanism when sphingolipids are incorporated into a cationic niosome formulation for non-viral gene delivery to central nervous system. For that, two formulations named niosphingosomes and niosomes devoid of sphingolipid extracts, as control, were developed by the oil-in water emulsion technique. Both formulations and the corresponding complexes, obtained upon the addition of the reporter EGFP plasmid, were physicochemically and biologically characterized and evaluated. Compared to niosomes, niosphingosomes, and the corresponding complexes decreased particle size and increased superficial charge. Although there were not significant differences in the cellular uptake, cell viability and transfection efficiency increased when human retinal pigment epithelial (ARPE-19) cells were exposed to niosphingoplexes. Endocytosis via caveolae decreased in the case of niosphingoplexes, which showed higher co-localization with lysosomal compartment, and endosomal escape properties. Moreover, niosphingoplexes transfected not only primary central nervous system cells, but also different cells in mouse retina, depending on the administration route, and brain cortex. These preliminary results suggest that niosphingosomes represent a promising non-viral vector formulation purposed for the treatment of both retinal and brain diseases by gene therapy approach.

How Far Are Non-Viral Vectors to Come of Age and Reach Clinical Translation in Gene Therapy?

Efficient delivery of genetic material into cells is a critical process to translate gene therapy into clinical practice. In this sense, the increased knowledge acquired during past years in the molecular biology and nanotechnology fields has contributed to the development of different kinds of non-viral vector systems as a promising alternative to virus-based gene delivery counterparts. Consequently, the development of non-viral vectors has gained attention, and nowadays, gene delivery mediated by these systems is considered as the cornerstone of modern gene therapy due to relevant advantages such as low toxicity, poor immunogenicity and high packing capacity. However, despite these relevant advantages, non-viral vectors have been poorly translated into clinical success. This review addresses some critical issues that need to be considered for clinical practice application of non-viral vectors in mainstream medicine, such as efficiency, biocompatibility, long-lasting effect, route of administration, design of experimental condition or commercialization process. In addition, potential strategies for overcoming main hurdles are also addressed. Overall, this review aims to raise awareness among the scientific community and help researchers gain knowledge in the design of safe and efficient non-viral gene delivery systems for clinical applications to progress in the gene therapy field.

Niosome-Based Approach for In Situ Gene Delivery to Retina and Brain Cortex as Immune-Privileged Tissues

Non-viral vectors have emerged as a promising alternative to viral gene delivery systems due to their safer profile. Among non-viral vectors, recently, niosomes have shown favorable properties for gene delivery, including low toxicity, high stability, and easy production. The three main components of niosome formulations include a cationic lipid that is responsible for the electrostatic interactions with the negatively charged genetic material, a non-ionic surfactant that enhances the long-term stability of the niosome, and a helper component that can be added to improve its physicochemical properties and biological performance. This review is aimed at providing recent information about niosome-based non-viral vectors for gene delivery purposes. Specially, we will discuss the composition, preparation methods, physicochemical properties, and biological evaluation of niosomes and corresponding nioplexes that result from the addition of the genetic material onto their cationic surface. Next, we will focus on the in situ application of such niosomes to deliver the genetic material into immune-privileged tissues such as the brain cortex and the retina. Finally, as future perspectives, non-invasive administration routes and different targeting strategies will be discussed.

Protamine-induced condensation of peptide nanofilaments into twisted bundles with controlled helical geometry

Chiral self-assembly of peptides is of fundamental interest in the field of biology and material science. Protamine, an alkaline biomacromolecule which is ubiquitous in fish and mammalian, plays crucial roles in directing the helical twisting of DNA. Inspired by this, we reported a bioinspired pathway to direct the hierarchical chiral self-assembly of a short synthetic dipeptide. The peptide could self-assemble into negatively charged chiral micelles in water that spontaneously formed a nematic liquid crystalline phase. By incorporation with protamine, the micelles condensed with the protamine into large helical bundles with precisely controlled diameter. Furthermore, to simulate the intracellular environments, we investigated macromolecular crowding on the coassembly of peptide and protamine, which leads to the formation of much thinner helical structures. The results highlight the roles of highly charged biomacromolecules and macromolecular crowding on peptide self-assembly, which are beneficial for the practical applications of self-assembling peptides in biomedicine and sensing.

PEGylated Protamine-Based Adsorbing Improves the Biological Properties and Stability of Tetrahedral Framework Nucleic Acids

Recently, many researchers have reported that DNA nanostructures, such as tetrahedral framework nucleic acids (tFNAs), have great potential to be useful tools in clinical and laboratory applications due to their programmable shapes, functional sites, and biological responses. However, finite endocytosis and stability in cells and body fluids compromise the functions of DNA nanostructures as a result of various adverse factors. In this study, we successfully synthesized PEGylated protamine, and tFNAs were adsorbed to it in a proper ratio of nitrogen in protamine to phosphorus in tFNAs (N/P ratio) as the functional complex. Furthermore, we demonstrated that PEGylated protamine-adsorbed tFNAs show a more prominent positive effect on cell viability and proliferation than naked tFNAs do. An increase in endocytosis can be observed in three different tissue-derived cells with the PEG-protamine-tFNA (PPT) complex. The increased endocytic ability is mediated by multiple pathways; moreover, the stimulatory effect of the PPT complex on the endocytic ability is dramatically blocked by the inhibition of the caveola-dependent pathway. Consistently, when tFNAs are stabilized by PEGylated protamine, they often tend to escape from lysosomes and survive for a longer period in biological fluids rather than being rapidly eliminated from the kidneys. The in vitro and in vivo results of our study demonstrate that the PPT complex method is a feasible, potent, and low-cost strategy that improves tFNA biocompatibility, stability, and internalization. This study provides evidence supporting the possibility of implementing PPTs for use in drug delivery, bioimaging, and gene transfection in the future.

Non-viral vectors based on cationic niosomes and minicircle DNA technology enhance gene delivery efficiency for biomedical applications in retinal disorders

Low transfection efficiency is a major challenge to overcome in non-viral approaches to reach clinical practice. Our aim was to explore new strategies to achieve more efficient non-viral gene therapies for clinical applications and in particular, for retinal diseases. Cationic niosomes and three GFP-encoding genetic materials consisting on minicircle (2.3 kb), its parental plasmid (3.5 kb) and a larger plasmid (5.5 kb) were combined to form nioplexes. Once fully physicochemically characterized, in vitro experiments in ARPE-19 retina epithelial cells showed that transfection efficiency of minicircle nioplexes doubled that of plasmids ones, maintaining good cell viability in all cases. Transfections in retinal primary cells and injections of nioplexes in rat retinas confirmed the higher capacity of cationic niosomes vectoring minicircle to deliver the genetic material into retina cells. Therefore, nioplexes based on cationic niosomes vectoring minicircle DNA represent a potential tool for the treatment of inherited retinal diseases.

Gene transfer to rat cerebral cortex mediated by polysorbate 80 and poloxamer 188 nonionic surfactant vesicles

Background

Gene therapy can be an intriguing therapeutic option in wide-ranging neurological disorders. Though nonviral gene carriers represent a safer delivery system to their viral counterparts, a thorough design of such vehicles is crucial to enhance their transfection properties.

Purpose

This study evaluated the effects of combined use of two nonionic surfactants, poloxamer 188 (P) and polysorbate 80 (P80) into nanovesicles – based on 2,3-di(tetradecyloxy)propan-1-amine cationic lipid (D) – destined for gene delivery to central nervous system cells.

Methods

Niosome formulations without and with poloxamer 188 (DP80 and DPP80, respectively) were prepared by the reverse-phase evaporation technique and characterized in terms of size, surface charge, and morphology. After the addition of pCMS-EGFP plasmid, the binding efficiency to the niosomes was evaluated in agarose gel electrophoresis assays. Additionally, transfection efficiency of complexes was also evaluated in in vitro and in vivo conditions.

Results

In vitro experiments on NT2 cells revealed that the complexes based on a surfactant combination (DPP80) enhanced cellular uptake and viability when compared with the DP80 counterparts. Interestingly, DPP80 complexes showed protein expression in glial cells after administration into the cerebral cortices of rats.

Conclusion

These data provide new insights for glia-centered approach for gene therapy of nervous system disorders using cationic nanovesicles, where nonionic surfactants play a pivotal role.

Nanoparticle-Based Delivery of CRISPR/Cas9 Genome-Editing Therapeutics

The recent progress in harnessing the efficient and precise method of DNA editing provided by CRISPR/Cas9 is one of the most promising major advances in the field of gene therapy. However, the development of safe and optimally efficient delivery systems for CRISPR/Cas9 elements capable of achieving specific targeting of gene therapy to the location of interest without off-target effects is a primary challenge for clinical therapeutics. Nanoparticles (NPs) provide a promising means to meet such challenges. In this review, we present the most recent advances in developing innovative NP-based delivery systems that efficiently deliver CRISPR/Cas9 constructs and maximize their effectiveness.

Non-viral vectors based on cationic niosomes as efficient gene delivery vehicles to central nervous system cells into the brain

Development of safe and efficient non-viral vectors to deliver DNA into the CNS represents a huge challenge to face many neurological disorders. We elaborated niosomes based on DOTMA cationic lipid, lycopene "helper" lipid and polysorbate 60 as non-ionic surfactants for gene delivery to the CNS. Niosomes, and their corresponding nioplexes obtained after the addition of the pCMS-EGFP plasmid, were characterized in terms of size, charge, morphology and capacity to condense, release and protect DNA. In vitro experiments were performed in NT2 cells to evaluate transfection efficiency, viability, cellular uptake and intracellular distribution. Additionally, transfection in primary cortex cells were performed prior to brain administration into rat cerebral cortex. Data obtained showed that nioplexes exhibited not only adequate physicochemical properties for gene delivery applications, but also relevant transfection efficiencies (17%), without hampering viability (90%). Interestingly, In vivo experiments depicted promising protein expression in both cortical glial cells and blood vessels.

Hyaluronic acid-modified cationic niosomes for ocular gene delivery: improving transfection efficiency in retinal pigment epithelium

OBJECTIVES

Recent years, gene therapy to treat retinal diseases has been paid much attention. The key to successful therapy is utilizing smart delivery system to achieve efficient gene delivery and transfection. In this study, hyaluronic acid (HA) modified cationic niosomes (HA-C-niosomes) have been designed in order to achieve retinal pigment epithelium (RPE) cells targeted gene delivery and efficient gene transfection.

METHODS

Cationic niosomes composed of tween 80/squalene/1, 2-dioleoyl-3-trimethylammonium-propane (DOTAP) were prepared by the ethanol injection method. After that, HA-DOPE was further added into cationic niosomes to form HA-C-niosomes. Cellular uptake and transfection have been investigated in ARPE-19 cells. In vivo pEGFP transfection efficiency was evaluated in rats.

KEY FINDINGS

Twenty percentage HA-C-niosomes were about 180 nm, with -30 mV, and showing spherical shape in TEM. 2 times higher transfection efficiency was found in the group of HA-C-niosomes with 20% HA modification. No toxicity was found in niosome preparations. In vivo evaluation in Sprague Dawley (SD) rats revealed that HA-C-niosomes could specifically target to the retina layer. In the group of pEGFP-loaded HA-C-niosomes, 6-6.5 times higher gene transfection has been achieved, compared with naked pEGFP.

CONCLUSIONS

Hyaluronic acid-C-niosomes might provide a promising gene delivery system for successful retinal gene therapy.

WITHDRAWN: Non-viral vectors based on cationic niosomes as efficient gene delivery vehicles to central nervous system cells into the brain

This article has been withdrawn: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been withdrawn at the request of the editor and publisher. The publisher regrets that an error occurred which led to the premature publication of this paper. This error bears no reflection on the article or its authors. The publisher apologizes to the authors and the readers for this unfortunate error.

Laminated chitosan-based composite sponges for transmucosal delivery of novel protamine-decorated tripterine phytosomes: Ex-vivo mucopenetration and in-vivo pharmacokinetic assessments

In the current study, laminated chitosan (CS):hydroxypropyl methylcellulose (HPMC) composite sponges were exploited as solid matrices for buccal delivery of tripterine phytosomes functionalized with novel mucopenetrating protamine layer (PRT-TRI-PHY). Tripterine (TRI) is a herbal drug widely investigated as a potential anticancer candidate against various types of cancers. However, clinical use of TRI is handicapped by its low oral bioavailability. To surmount TRI pharmaceutical obstacles, TRI phytosomes (TRI-PHY) were prepared using solvent evaporation technique then coated with a protamine layer via electrostatic assembly process. The developed PRT-TRI-PHY showed a nano-metric size of 250 nm and positive zeta potential (+21.6 mV). Sponges loaded with PRT-TRI-PHY demonstrated a sustained release profile with superior mucoadhesion characteristics compared with the counterparts loaded with uncoated TRI-PHY. The ex-vivo permeation study via chicken pouch mucosa revealed that sponges loaded with PRT-TRI-PHY demonstrated 2.3-folds higher flux value compared with sponges loaded with uncoated TRI-PHY. Additionally, in-vivo pharmacokinetic study in healthy rabbits revealed the significantly higher bioavailability of PRT-TRI-PHY compared with TRI-PHY with relative bioavailability of 244%. Conclusively, mucoadhesive CS-HPMC sponges loaded with a novel mucopenetrating nanocarrier, PRT-TRI-PHY, could significantly improve the absorption of tripterine via buccal mucosa which would be of prime importance for its clinical utility.

Stem cell-based gene delivery mediated by cationic niosomes for bone regeneration

Bone morphogenetic protein-7(BMP-7) plays a pivotal role in the transformation of mesenchymal stem cells (MSCs) into bone. However, its impact is hampered due to its short half-life. Therefore, gene therapy may be an interesting approach to deliver BMP-7 gene to D1-MSCs. In this manuscript we prepared and characterized niosomes based on cationic lipid 2,3-di(tetradecyloxy)propan-1-amine, combined with polysorbate 80 for gene delivery purposes. Niosomes were characterized and combined initially with pCMS-EGFP reporter plasmid, and later with pUNO1-hBMP-7 plasmid to evaluate osteogenesis differentiation. Additionally, specific blockers of most relevant endocytic pathways were used to evaluate the intracellular disposition of complexes. MSCs transfected with niosomes showed increased growth rate, enhanced alkaline phosphatase activity (ALP) and extracellular matrix deposition which suggested the formation of osteoblast-like cells. We concluded that hBMP-7-transfected MSCs could be considered not only as an effective delivery tool of hBMP-7, but also as proliferating and bone forming cells for bone regeneration.

Ternary complex of plasmid DNA with NLS-Mu-Mu protein and cationic niosome for biocompatible and efficient gene delivery: a comparative study with protamine and lipofectamine

Non-viral gene delivery methods are considered due to safety and simplicity in human gene therapy. Since the use of cationic peptide and niosome represent a promising approach for gene delivery purposes we used recombinant fusion protein and cationic niosome as a gene carrier. A multi-domain fusion protein including nuclear localization motif (NLS) and two DNA-binding (Mu) domains, namely NLS-Mu-Mu (NMM) has been designed, cloned and expressed in E. coli DE3 strain. Afterward, the interested protein was purified by affinity chromatography. Binary vectors based on protein/DNA and ternary vectors based on protein/DNA/niosome were prepared. Protamine was used as a control. DNA condensing properties of NMM and protamine were evaluated by various experiments. Furthermore, we examined cytotoxicity, hemolysis and transfection potential of the binary and ternary complexes in HEK293T and MCF-7 cell lines. Protamine and Lipofectamine™2000 were used as positive controls, correspondingly. The recombinant NMM was expressed and purified successfully and DNA was condensed efficiently at charge ratios that were not harmful to cells. Peptidoplexes showed transfection efficiency (TE) but ternary complexes had higher TE. Additionally, NMM ternary complex was more efficient compared to protamine ternary vectors. Our results showed that niosomal ternary vector of NMM is a promising non-viral gene carrier to achieve an effective and safe carrier system for gene therapy.

Approaches in topical ocular drug delivery and developments in the use of contact lenses as drug-delivery devices

Drug-delivery approaches have diversified over the last two decades with the emergence of nanotechnologies, smart polymeric systems and multimodal functionalities. The intended target for specific treatment of disease is the key defining developing parameter. One such area which has undergone significant advancements relates to ocular delivery. This has been expedited by the development of material advancement, mechanistic concepts and through the deployment of advanced process technologies. This review will focus on the developments within lens-based drug delivery while touching on conventional and current methods of topical ocular drug delivery. A summary table will provide quick reference to note the key findings in this area. In addition, the review also elucidates current theranostic and diagnostic approaches based on ocular lenses.

Retinal gene delivery enhancement by lycopene incorporation into cationic niosomes based on DOTMA and polysorbate 60

The present study aimed to evaluate the incorporation of the natural lipid lycopene into niosome formulations based on cationic lipid DOTMA and polysorbate 60 non-ionic surfactant to analyze the potential application of this novel formulation to deliver genetic material into the rat retina. Both niosomes with and without lycopene were prepared by the reverse phase evaporation method and physicochemically characterized in terms of size, zeta potential, polydispersity index and capacity to condense, release and protect the DNA against enzymatic digestion. In vitro experiments were performed in ARPE-19 cells after complexion of niosomes with pCMS-EGFP plasmid at appropriate cationic lipid/DNA ratios. At 18/1 mass ratio, nioplexes containing lycopene had nanometric size, positive zeta potential, low polydispersity and were able to condense, release and protect DNA. Percentage of transfected cell was around 35% without compromising cell viability. The internalization pathways studies revealed a preference to caveolae mediated endocytosis and macropinocytosis, which could circumvent lysosomal degradation. Both subretinal and intravitreal administrations to the rat retina showed that nioplexes were able to transfect efficiently the outer segments of the retina, which offer reasonable hope for the treatment of many inherited retinal diseases by a safe non-viral vector formulation after the less invasive intravitreal administration.

Synthetic nanocarriers for the delivery of polynucleotides to the eye

This review is a comprehensive analysis of the progress made so far on the delivery of polynucleotide-based therapeutics to the eye, using synthetic nanocarriers. Attention has been addressed to the capacity of different nanocarriers for the specific delivery of polynucleotides to both, the anterior and posterior segments of the eye, with emphasis on their ability to (i) improve the transport of polynucleotides across the different eye barriers; (ii) promote their intracellular penetration into the target cells; (iii) protect them against degradation and, (iv) deliver them in a long-term fashion way. Overall, the conclusion is that despite the advantages that nanotechnology may offer to the area of ocular polynucleotide-based therapies (especially AS-ODN and siRNA delivery), the knowledge disclosed so far is still limited. This fact underlines the necessity of more fundamental and product-oriented research for making the way of the said nanotherapies towards clinical translation.

Inhaled gene delivery: a formulation and delivery approach

INTRODUCTION

Gene therapy is a potential alternative to treat a number of diseases. Different hurdles are associated with aerosol gene delivery due to the susceptibility of plasmid DNA (pDNA) structure to be degraded during the aerosolization process. Different strategies have been investigated in order to protect and efficiently deliver pDNA to the lungs using non-viral vectors. To date, no successful therapy involving non-viral vectors has been marketed, highlighting the need for further investigation in this field. Areas covered: This review is focused on the formulation and delivery of DNA to the lungs, using non-viral vectors. Aerosol gene formulations are divided according to the current delivery systems for the lung: nebulizers, dry powder inhalers and pressurized metered dose inhalers; highlighting its benefits, challenges and potential application. Expert opinion: Successful aerosol delivery is achieved when the supercoiled DNA structure is protected during aerosolization. A formulation strategy or compounds that can protect, stabilize and efficiently transfect DNA into the cells is desired in order to produce an effective, low-cost and safe formulation. Nebulizers and dry powder inhalers are the most promising approaches to be used for aerosol delivery, due to the lower shear forces involved. In this context it is also important to highlight the importance of considering the 'pDNA-formulation-device system' as an integral part of the formulation development for a successful nucleic acid delivery.