Role of liposome and peptide in the synergistic enhancement of transfection with a lipopolyplex vector

Topical gene editing therapeutics using lipid nanoparticles: 'gene creams' for genetic skin diseases?

Patients living with inherited skin diseases have benefited from recent advances in DNA sequencing technologies that provide new or improved diagnostics. However, developing and delivering new treatments for the 'genodermatoses' remains challenging. The goal of creating topical preparations that can recover the inherent gene pathology remains largely aspirational. However, recent progress in two fields - the chemistry of topical delivery formulations (lipid nanoparticles) and the molecular biology of gene repair (CRISPR-Cas9, base and prime editing) - presents new opportunities to address this unmet need. In this review, we discuss how lipid nanoparticle delivery vehicles could be used to deliver gene-editing tools to formulate topical 'gene creams' suitable for the treatment of genodermatoses. We summarize the historical landscape of topical therapeutics and advances in gene editing that may herald an era of new therapies for patients with inherited skin disorders.

Dual-loaded liposomal carriers to combat chemotherapeutic resistance in breast cancer

INTRODUCTION

The resistance to chemotherapy is a significant hurdle in breast cancer treatment, prompting the exploration of innovative strategies. This review discusses the potential of dual-loaded liposomal carriers to combat chemoresistance and improve outcomes for breast cancer patients.

AREAS COVERED

This review discusses breast cancer chemotherapy resistance and dual-loaded liposomal carriers. Drug efflux pumps, DNA repair pathways, and signaling alterations are discussed as chemoresistance mechanisms. Liposomes can encapsulate several medicines and cargo kinds, according to the review. It examines how these carriers improve medication delivery, cancer cell targeting, and tumor microenvironment regulation. Also examined are dual-loaded liposomal carrier improvement challenges and techniques.

EXPERT OPINION

The use of dual-loaded liposomal carriers represents a promising and innovative strategy in the battle against chemotherapy resistance in breast cancer. This article has explored the various mechanisms of chemoresistance in breast cancer, emphasizing the potential of dual-loaded liposomal carriers to overcome these challenges. These carriers offer versatility, enabling the encapsulation and precise targeting of multiple drugs with different modes of action, a crucial advantage when dealing with the complexity of breast cancer treatment.

Molecular and functional correction of a deep intronic splicing mutation in CFTR by CRISPR-Cas9 gene editing

Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in the CFTR gene. The 10th most common mutation, c.3178-2477C>T (3849+10kb C>T), involves a cryptic, intronic splice site. This mutation was corrected in CF primary cells homozygous for this mutation by delivering pairs of guide RNAs (gRNAs) with Cas9 protein in ribonucleoprotein (RNP) complexes that introduce double-strand breaks to flanking sites to excise the 3849+10kb C>T mutation, followed by DNA repair by the non-homologous end-joining pathway, which functions in all cells of the airway epithelium. RNP complexes were delivered to CF basal epithelial cell by a non-viral, receptor-targeted nanocomplex comprising a formulation of targeting peptides and lipids. Canonical CFTR mRNA splicing was, thus, restored leading to the restoration of CFTR protein expression with concomitant restoration of electrophysiological function in airway epithelial air-liquid interface cultures. Off-target editing was not detected by Sanger sequencing of in silico-selected genomic sites with the highest sequence similarities to the gRNAs, although more sensitive unbiased whole genome sequencing methods would be required for possible translational developments. This approach could potentially be used to correct aberrant splicing signals in several other CF mutations and other genetic disorders where deep-intronic mutations are pathogenic.

Folding-Mediated DNA Delivery by α-Helical Amphipathic Peptides

The renaissance gene therapy experiences these days requires specialist biomaterials and a systemic understanding of major factors influencing their ability to deliver genetic material. Peptide transfection systems represent a major class of such biomaterials. Several peptidic reagents have been commercialized to date. However, a comparative assessment of peptide sequences alone without auxiliary support or excipients against a common determinant for their ability to complex and deliver DNA has been lacking. This study cross-compares commercial and experimental transfection reagents from the same family of helical amphiphiles. Factors defining the efficacy of DNA delivery including cell uptake and gene expression are assessed along with cytotoxicity and DNA complexation. The results show that despite differences in sequence composition, length, and origin, peptide reagents of the same structural family exhibit similar characteristics and limitations with common variability trends. The cross-comparison revealed that functional DNA delivery is independent of the peptide sequence used but is mediated by the ability of the reagents to co-fold with DNA. Peptide folding proved to be the common determinant for DNA complexation and delivery by peptidic transfection reagents.

Lipid-peptide nanocomplexes for mRNA delivery in vitro and in vivo

Despite recent advances in the field of mRNA therapy, the lack of safe and efficacious delivery vehicles with pharmaceutically developable properties remains a major limitation. Here, we describe the systematic optimisation of lipid-peptide nanocomplexes for the delivery of mRNA in two murine cancer cell types, B16-F10 melanoma and CT26 colon carcinoma as well as NCI-H358 human lung bronchoalveolar cells. Different combinations of lipids and peptides were screened from an original lipid-peptide nanocomplex formulation for improved luciferase mRNA transfection in vitro by a multi-factorial screening approach. This led to the identification of key structural elements within the nanocomplex associated with substantial improvements in mRNA transfection efficiency included alkyl tail length of the cationic lipid, the fusogenic phospholipid, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and cholesterol. The peptide component (K₁₆GACYGLPHKFCG) was further improved by the inclusion of a linker, RVRR, that is cleavable by the endosomal enzymes cathepsin B and furin, and a hydrophobic motif (X-S-X) between the mRNA packaging (K₁₆) and receptor targeting domains (CYGLPHKFCG). Nanocomplex transfections of a murine B16-F10 melanoma tumour supported the inclusion of cholesterol for optimal transfection in vivo as well as in vitro. In vitro transfections were also performed with mRNA encoding interleukin-15 as a potential immunotherapy agent and again, the optimised formulation with the key structural elements demonstrated significantly higher expression than the original formulation. Physicochemical characterisation of the nanocomplexes over time indicated that the optimal formulation retained biophysical properties such as size, charge and mRNA complexation efficiency for 14 days upon storage at 4 °C without the need for additional stabilising agents. In summary, we have developed an efficacious lipid-peptide nanocomplex with promising pharmaceutical development properties for the delivery of therapeutic mRNA.

"One-stitch" bioorthogonal prodrug activation based on cross-linked lipoic acid nanocapsules

Bioorthogonal prodrug activation is fascinating but suffers from staggered administration of prodrug and trigger, which would not only reduce the therapeutic effect but bring great inconvenience for clinical application. Herein, we report a new cross-linked lipoic acid nanocapsules (cLANCs) based two-component bioorthogonal nanosystem for "one-stitch" prodrug activation. Due to the reversible stability of cLANCs, the loaded prodrug and trigger cannot release in advance while can react upon arrival in the tumor tissue. Moreover, the cLANCs would be degraded into dihydrolipoic acid in tumor cells to potentiate the anticancer effect of the drug synthesized in situ. The data showed that the new bioorthogonal system held a killing effect 1.63 times higher than that of parent drug 3 against human colorectal tumor cells (HT29) and a tumor inhibitory rate 34.2% higher than that of 3 against HT29 tumor xenograft model with negligible side effects. The biodistribution study showed that the "one-stitch" prodrug activation exhibited a selective accumulation of 3 in the tumor tissue compared with free 3 group (34.2 μg vs 3.56 μg of 3/g of tissue). This two-component bioorthogonal nanosystem based on cross-linked lipoic acid nanocapsules constitutes the first example of "one-stitch" bioorthogonal prodrug activation.

Peptide-functionalized liposomes as therapeutic and diagnostic tools for cancer treatment

Clinically efficacious medication in anticancer therapy has been successfully designed with liposome-based nanomedicine. The liposomal formulation in cancer drug delivery can be facilitated with a functionalized peptide that mediates the specific drug delivery opportunities with increased drug penetrability, specific accumulation in the targeted site, and enhanced therapeutic efficacy. This review aims to focus on recent advances in peptide-functionalized liposomal formulation techniques in cancer diagnosis and treatment regarding recently published literature. It also will highlight different aspects of novel liposomal formulation techniques that incorporate surface functionalization with peptides for better anticancer effect and current challenges in peptide-functionalized liposomal drug formulation.

Advances in the Application of Liposomal Nanosystems in Anticancer Therapy

Cancer is the disease with the highest mortality rate, which poses a great threat to people's lives. Cancer caused approximately 3.4 million death worldwide annually. Surgery, chemotherapy and radiotherapy are the main therapeutic methods in clinical practice. However, surgery is only suitable for patients with early-stage cancers, and chemotherapy as well as radiotherapy have various side effects, both of which limit the application of available therapeutic methods. In 1965, liposome was firstly developed to form new drug delivery systems given the unique properties of nanoparticles, such as enhanced permeability and retention effect. During the last 5 decades, liposome has been widely used for the purpose of anticancer drug delivery, and several advances have been made regarding liposomal technology, including long-circulating liposomes, active targeting liposomes and triggered release liposomes, while problems exist all along. This review introduced the advances as well as the problems during the development of liposomal nanosystems for cancer therapy in recent years.

Creation of Cultures Containing Mutations Linked with Cardiovascular Diseases using Transfection and Genome Editing

OBJECTIVE

In this review article, we analyzed the literature on the creation of cultures containing mutations associated with cardiovascular diseases (CVD) using transfection, transduction and editing of the human genome.

METHODS

We described different methods of transfection, transduction and editing of the human genome, used in the literature.

RESULTS

We reviewed the researches in which the creation of сell cultures containing mutations was described. According to the literature, system CRISPR/Cas9 proved to be the most preferred method for editing the genome. We found rather promising and interesting a practically undeveloped direction of mitochondria transfection using a gene gun. Such a gun can direct a genetically-engineered construct containing human DNA mutations to the mitochondria using heavy metal particles. However, in human molecular genetics, the transfection method using a gene gun is unfairly forgotten and is almost never used. Ethical problems arising from editing the human genome were also discussed in our review. We came to a conclusion that it is impossible to stop scientific and technical progress. It is important that the editing of the genome takes place under the strict control of society and does not bear dangerous consequences for humanity. To achieve this, the constant interaction of science with society, culture and business is necessary.

CONCLUSION

The most promising methods for the creation of cell cultures containing mutations linked with cardiovascular diseases, were system CRISPR/Cas9 and the gene gun.

Gastrin-releasing peptide receptor-targeted hybrid peptide/phospholipid pDNA/siRNA delivery systems

Aim: To develop a peptide/phospholipid hybrid system for gastrin-releasing peptide receptor (GRPR)-targeted delivery of pDNA or siRNA. Materials & methods: A multifunctional GRPR-targeted peptide R₉-K(GALA)-BBN(6-14) was combined with a phospholipid oligonucleotide delivery system (1:1 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine and 1,2-dioleoyl-3-trimethylammonium-propane) and evaluated for pDNA and siRNA delivery in terms of complex size, toxicity, receptor-targeted delivery and gene expression or knockdown efficiency. Results: By combining peptide and phospholipid delivery systems, synergistic improvements in gene expression and knockdown were observed when compared with either system alone. The optimized formulation demonstrated high levels of EGFP expression and EGFP knockdown, GRPR-targeted delivery, enhanced endosomal release and minimal toxicity. Conclusion: The peptide/phospholipid hybrid system provides efficient GRPR-targeted DNA/siRNA delivery.

Intelligent TAT-coupled anti-HER2 immunoliposomes knock downed MDR1 to produce chemosensitize phenotype of multidrug resistant carcinoma

Gene therapy using biocompatible cationic liposomes is amongst promising approaches that decreases death from cancers. Here an invasive multidrug resistant cell model has been developed by lentiviral transfection. In parallel phospholipids have been covalently conjugated to TAT, MMP2, and Herceptin. The functional lipids have been mixed to generate intelligent liposome harboring small interfering RNA (siRNA) with high efficiency. The final liposomal complex was uniformly monodisperse and particle dimension and zeta-potential were respectively around 200 nm and -42.21 mV. Minimal cytotoxic effects have been reported for nanocarriers due to good biocompatibility of the selected phospholipids. Flourescence-activated cell sorter (FACS) analyses have been represented that surface trastuzumab and TAT specifically promote cellular uptake of liposomes in the malignant tumor cells. Assessment of MDR1 transcript and protein expression has been exhibited maximum significant downregulation around of 128-fold and 50-fold, respectively after 48 hr of liposome exposure. As it has been concluded, targeted liposomes may become a potential tool in gene delivery for improving chemotherapeutic efficiency in cancer treatment.

Tuning the Handedness: Role of Chiral Component in Peptide-Appended Bolaamphiphile-Based Coassembled Hydrogels

Chirality is the intrinsic property of a molecule that can be tuned by the change in chirality of a molecule or by the addition of a chiral component as an external stimulus. An l-leucine-based dipeptide-appended succinic acid-based bolaamphiphile coassembled with d-tartaric acid to form supramolecular right-handed nanostructured hydrogel, whereas l-tartaric acid coassembled to form supramolecular left-handed nanostructured hydrogel. Scanning electron microscopy and transmission electron microscopy experiments revealed the right- and left-handed helical nanofibers that are responsible for the formation of supramolecular nanostructured hydrogels. The synergistic chiral effect of l-leucine in peptide bolaamphiphile and d/l-tartaric acid plays a significant role in bicomponent gelation with helical nanofibers. The first two amino acids attached to both sides of succinic acid moiety act as a tuning button for supramolecular chirality of amino acids/peptides attached with succinic acid-based bolaamphiphiles. The second amino acid plays the role of modulating supramolecular chirality if the first two amino acids act neutrally to the chirality of bolaamphiphiles, which was confirmed by circular dichroism spectroscopy.

Development of lipopolyplexes for gene delivery: A comparison of the effects of differing modes of targeting peptide display on the structure and transfection activities of lipopolyplexes

The design, synthesis and formulation of non-viral gene delivery vectors is an area of renewed research interest. Amongst the most efficient non-viral gene delivery systems are lipopolyplexes, in which cationic peptides are co-formulated with plasmid DNA and lipids. One advantage of lipopolyplex vectors is that they have the potential to be targeted to specific cell types by attaching peptide targeting ligands on the surface, thus increasing both the transfection efficiency and selectivity for disease targets such as cancer cells. In this paper, we have investigated two different modes of displaying cell-specific peptide targeting ligands at the surface of lipopolyplexes. Lipopolyplexes formulated with bimodal peptides, with both receptor binding and DNA condensing sequences, were compared with lipopolyplexes with the peptide targeting ligand directly conjugated to one of the lipids. Three EGFR targeting peptide sequences were studied, together with a range of lipid formulations and maleimide lipid structures. The biophysical properties of the lipopolyplexes and their transfection efficiencies in a basal-like breast cancer cell line were investigated using plasmid DNA bearing genes for the expression of firefly luciferase and green fluorescent protein. Fluorescence quenching experiments were also used to probe the macromolecular organisation of the peptide and pDNA components of the lipopolyplexes. We demonstrated that both approaches to lipopolyplex targeting give reasonable transfection efficiencies, and the transfection efficiency of each lipopolyplex formulation is highly dependent on the sequence of the targeting peptide. To achieve maximum therapeutic efficiency, different peptide targeting sequences and lipopolyplex architectures should be investigated for each target cell type.

Liposomal Drug Delivery Systems and Anticancer Drugs

Cancer is a life-threatening disease contributing to ~3.4 million deaths worldwide. There are various causes of cancer, such as smoking, being overweight or obese, intake of processed meat, radiation, family history, stress, environmental factors, and chance. The first-line treatment of cancer is the surgical removal of solid tumours, radiation therapy, and chemotherapy. The systemic administration of the free drug is considered to be the main clinical failure of chemotherapy in cancer treatment, as limited drug concentration reaches the tumour site. Most of the active pharmaceutical ingredients (APIs) used in chemotherapy are highly cytotoxic to both cancer and normal cells. Accordingly, targeting the tumour vasculatures is essential for tumour treatment. In this context, encapsulation of anti-cancer drugs within the liposomal system offers secure platforms for the targeted delivery of anti-cancer drugs for the treatment of cancer. This, in turn, can be helpful for reducing the cytotoxic side effects of anti-cancer drugs on normal cells. This short-review focuses on the use of liposomes in anti-cancer drug delivery.

Nanoliposomes for Safe and Efficient Therapeutic mRNA Delivery: A Step Toward Nanotheranostics in Inflammatory and Cardiovascular Diseases as well as Cancer

Rationale: Genetic therapy using modified mRNA for specific therapeutic protein expression for disease treatment and vaccination represents a new field of therapeutic and diagnostic medicine. Non-viral vectors transfection using biocompatible nanoliposomes enables safe and efficient delivery of therapeutic mRNA. Objective: Generation of non-toxic, cell-compatible cationic nanoliposomes as nanotheranostic agents to successfully deliver therapeutic mRNA. Methods and results: Cationic nanoliposomes (DC-Cholesterol/DOPE) were generated as transfection vehicles for either eGFP mRNA or the therapeutic anti-inflammatory, CD39 mRNA. We observed no toxicity using these nanoplexes and noted high cell viability after transfection. Nanoplexes for the transfection of eGFP mRNA showed an increase in fluorescence signals on microscopy as compared to the mRNA control after 24 hours in Chinese hamster ovary (CHO) cells (14.29 ± 5.30 vs. 1.49 ± 0.54; mean ± SD respectively; p<0.001) and flow cytometry (57.29 ± 14.59 vs 1.83 ± 0.34; % mean ± SD; p<0.001). Nanoplexes for the transfection of CD39 mRNA showed increased CD39 expression in flow cytometry (45.64 ± 15.3 vs. 3.94 ± 0.45; % mean ± SD; p<0.001) as compared to the mRNA control after 24 hours using CHO cells. We also demonstrated efficient transfection across several cell lines (CHO, HEK293, and A549), as well as long-term protein expression (120 h and 168 h) using these nanoplexes. Conclusions: We have developed and tested non-toxic, safe, and efficient nanoliposome preparations for the delivery of therapeutic mRNA that hold promise for novel therapies in diseases such as inflammatory and cardiovascular diseases, as well as cancer. We have also demonstrated that this approach provides a reliable technology to deliver CD39 mRNA as an anti-inflammatory therapeutic for future nanotheranostics approaches.

Peptide and nucleic acid-directed self-assembly of cationic nanovehicles through giant unilamellar vesicle modification: Targetable nanocomplexes for in vivo nucleic acid delivery

One of the greatest challenges for the development of genetic therapies is the efficient targeted delivery of therapeutic nucleic acids. Towards this goal, we have introduced a new engineering initiative in self-assembly of biologically safe and stable nanovesicle complexes (∼90 to 140nm) derived from giant unilamellar vesicle (GUV) precursors and comprising plasmid DNA or siRNA and targeting peptide ligands. The biological performance of the engineered nanovesicle complexes were studied both in vitro and in vivo and compared with cationic liposome-based lipopolyplexes. Compared with cationic lipopolyplexes, nanovesicle complexes did not show advantages in transfection and cell uptake. However, nanovesicle complexes neither displayed significant cytotoxicity nor activated the complement system, which are advantageous for intravenous injection and tumour therapy. On intravenous administration into a neuroblastoma xenograft mouse model, nanovesicle complexes were found to distribute throughout the tumour interstitium, thus providing an alternative safer approach for future development of tumour-specific therapeutic nucleic acid interventions. On oropharyngeal instillation, nanovesicle complexes displayed better transfection efficiency than cationic lipopolyplexes. The technological advantages of nanovesicle complexes, originating from GUVs, over traditional cationic liposome-based lipopolyplexes are discussed.

STATEMENT OF SIGNIFICANCE

The efficient targeted delivery of nucleic acids in vivo provides some of the greatest challenges to the development of genetic therapies. Giant unilamellar lipid vesicles (GUVs) have been used mainly as cell and tissue mimics and are instrumental in studying lipid bilayers and interactions. Here, the GUVs have been modified into smaller nanovesicles. We have then developed novel nanovesicle complexes comprising self-assembling mixtures of the nanovesicles, plasmid DNA or siRNA, and targeting peptide ligands. Their biophysical properties were studied and their transfection efficiency was investigated. They transfected cells efficiently without any associated cytotoxicity and with targeting specificity, and in vivo they resulted in very high and tumour-specific uptake and in addition, efficiently transfected the lung. The peptide-targeted nanovesicle complexes allow for the specific targeted enhancement of nucleic acid delivery with improved biosafety over liposomal formulations and represent a promising tool to improve our arsenal of safe, non-viral vectors to deliver therapeutic cargos in a variety of disorders.

Chemical Synthesis, Versatile Structures and Functions of Tailorable Adjuvants for Optimizing Oral Vaccination

Oral vaccines have become a recent focus because of their potential significance in disease prevention and therapy. In the development of oral vaccine-based therapeutics, synthetic materials with tailorable structures and versatile functions can act as antigen conveyers with adjuvant effects, reduce the time cost for vaccine optimization, and provide high security and enhanced immunity. This review presents an overview of the current status of tailoring synthetic adjuvants for oral vaccination, modification strategies for producing effectors with specific structures and functions, enhancement of immune-associated efficiencies, including the barrier-crossing capability to protect antigens in the gastrointestinal tract, coordination of the antigens penetrating mucosa and cell barriers, targeting of concentrated antigens to immune-associated cells, and direct stimulation of immune cells. Finally, we focus on prospective synthetic adjuvants that facilitate the use of oral vaccines via two approaches, namely, in vivo antigen expression and cancer immunotherapy.

Effect of inserted spacer in hepatic cell-penetrating multifunctional peptide component on the DNA intracellular delivery of quaternary complexes based on modular design

A safe and efficient quaternary gene delivery system (named Q-complexes) was constructed based on self-assembly of molecules through noncovalent bonds. This system was formulated through the cooperation and competing interactions of cationic liposomes, multifunctional peptides, and DNA, followed by coating hyaluronic acid on the surface of the ternary complexes. The multifunctional peptide was composed of two functional domains: penetrating hepatic tumor-targeted cell moiety (KRPTMRFRYTWNPMK) and a wrapping gene sequence (polyarginine 16). The effect of spacer insertion between the two domains of multifunctional peptide on the intracellular transfection of Q-complexes was further studied. Experimental results showed that the formulations assembled with various peptides in the spacer elements possessed different intercellular pathways and transfection efficiencies. The Q-complexes containing peptide in the absence of spacer element (P_a) showed the highest gene expression among all samples. The Q-complexes containing peptides with a noncleavable spacer GA (P_c) had no ability of intracellular nucleic acid delivery, whereas those with a cleavable spacer RVRR (P_d) showed moderate transfection activity. These results demonstrated that the different spacers inserted in the multifunctional peptide played an important role in in vitro DNA transfection efficiency. Atomic force microscopy images showed that the morphologies of ternary complexes (LP_cD) and Q-complexes (HL_cPD) were crystal lamellas, whereas those of other nanocomplexes were spheres. Circular dichroism showed the changed configuration of peptide with spacer GA in nanocomplexes compared with that of its free state, whereas the P_a configuration without spacer in nanocomplexes was consistent with that of its free state. The present study contributed to the structural understanding of Q-complexes, and further effective modification is in progress.

Lipopolyplex for Therapeutic Gene Delivery and Its Application for the Treatment of Parkinson's Disease

Lipopolyplex is a core-shell structure composed of nucleic acid, polycation and lipid. As a non-viral gene delivery vector, lipopolyplex combining the advantages of polyplex and lipoplex has shown superior colloidal stability, reduced cytotoxicity, extremely high gene transfection efficiency. Following intravenous administration, there are many strategies based on lipopolyplex to overcome the complex biological barriers in systemic gene delivery including condensation of nucleic acids into nanoparticles, long circulation, cell targeting, endosomal escape, release to cytoplasm and entry into cell nucleus. Parkinson's disease (PD) is the second most common neurodegenerative disorder and severely influences the patients' life quality. Current gene therapy clinical trials for PD employing viral vectors didn't achieve satisfactory efficacy. However, lipopolyplex may become a promising alternative approach owing to its stability in blood, ability to cross the blood-brain barrier (BBB) and specific targeting to diseased brain cells.

High content analysis platform for optimization of lipid mediated CRISPR-Cas9 delivery strategies in human cells

Non-viral gene-editing of human cells using the CRISPR-Cas9 system requires optimized delivery of multiple components. Both the Cas9 endonuclease and a single guide RNA, that defines the genomic target, need to be present and co-localized within the nucleus for efficient gene-editing to occur. This work describes a new high-throughput screening platform for the optimization of CRISPR-Cas9 delivery strategies. By exploiting high content image analysis and microcontact printed plates, multi-parametric gene-editing outcome data from hundreds to thousands of isolated cell populations can be screened simultaneously. Employing this platform, we systematically screened four commercially available cationic lipid transfection materials with a range of RNAs encoding the CRISPR-Cas9 system. Analysis of Cas9 expression and editing of a fluorescent mCherry reporter transgene within human embryonic kidney cells was monitored over several days after transfection. Design of experiments analysis enabled rigorous evaluation of delivery materials and RNA concentration conditions. The results of this analysis indicated that the concentration and identity of transfection material have significantly greater effect on gene-editing than ratio or total amount of RNA. Cell subpopulation analysis on microcontact printed plates, further revealed that low cell number and high Cas9 expression, 24h after CRISPR-Cas9 delivery, were strong predictors of gene-editing outcomes. These results suggest design principles for the development of materials and transfection strategies with lipid-based materials. This platform could be applied to rapidly optimize materials for gene-editing in a variety of cell/tissue types in order to advance genomic medicine, regenerative biology and drug discovery.

STATEMENT OF SIGNIFICANCE

CRISPR-Cas9 is a new gene-editing technology for "genome surgery" that is anticipated to treat genetic diseases. This technology uses multiple components of the Cas9 system to cut out disease-causing mutations in the human genome and precisely suture in therapeutic sequences. Biomaterials based delivery strategies could help transition these technologies to the clinic. The design space for materials based delivery strategies is vast and optimization is essential to ensuring the safety and efficacy of these treatments. Therefore, new methods are required to rapidly and systematically screen gene-editing efficacy in human cells. This work utilizes an innovative platform to generate and screen many formulations of synthetic biomaterials and components of the CRISPR-Cas9 system in parallel. On this platform, we watch genome surgery in action using high content image analysis. These capabilities enabled us to identify formulation parameters for Cas9-material complexes that can optimize gene-editing in a specific human cell type.

Minicircle DNA Provides Enhanced and Prolonged Transgene Expression Following Airway Gene Transfer

Gene therapy for cystic fibrosis using non-viral, plasmid-based formulations has been the subject of intensive research for over two decades but a clinically viable product has yet to materialise in large part due to inefficient transgene expression. Minicircle DNA give enhanced and more persistent transgene expression compared to plasmid DNA in a number of organ systems but has not been assessed in the lung. In this study we compared minicircle DNA with plasmid DNA in transfections of airway epithelial cells. In vitro, luciferase gene expression from minicircles was 5–10-fold higher than with plasmid DNA. In eGFP transfections in vitro both the mean fluorescence intensity and percentage of cells transfected was 2–4-fold higher with minicircle DNA. Administration of equimolar amounts of DNA to mouse lungs resulted in a reduced inflammatory response and more persistent transgene expression, with luciferase activity persisting for 2 weeks from minicircle DNA compared to plasmid formulations. Transfection of equal mass amounts of DNA in mouse lungs resulted in a 6-fold increase in transgene expression in addition to more persistent transgene expression. Our findings have clear implications for gene therapy of airway disorders where plasmid DNA transfections have so far proven inefficient in clinical trials.

Receptor-targeted liposome-peptide-siRNA nanoparticles represent an efficient delivery system for MRTF silencing in conjunctival fibrosis

There is increasing evidence that the Myocardin-related transcription factor/Serum response factor (MRTF/SRF) pathway plays a key role in fibroblast activation and that knocking down MRTF can lead to reduced scarring and fibrosis. Here, we have developed a receptor-targeted liposome-peptide-siRNA nanoparticle as a non-viral delivery system for MRTF-B siRNA in conjunctival fibrosis. Using 50 nM siRNA, the MRTF-B gene was efficiently silenced by 76% and 72% with LYR and LER nanoparticles, respectively. The silencing efficiency was low when non-targeting peptides or siRNA alone or liposome-siRNA alone were used. LYR and LER nanoparticles also showed higher silencing efficiency than PEGylated LYR-P and LER-P nanoparticles. The nanoparticles were not cytotoxic using different liposomes, targeting peptides, and 50 nM siRNA. Three-dimensional fibroblast-populated collagen matrices were also used as a functional assay to measure contraction in vitro, and showed that MRTF-B LYR nanoparticles completely blocked matrix contraction after a single transfection treatment. In conclusion, this is the first study to develop and show that receptor-targeted liposome-peptide-siRNA nanoparticles represent an efficient and safe non-viral siRNA delivery system that could be used to prevent fibrosis after glaucoma filtration surgery and other contractile scarring conditions in the eye.

Characteristics of Cell-Penetrating Peptide/Nucleic Acid Nanoparticles

Nucleic acids are highly promising candidates for the treatment of various genetic diseases. However, due to the large size and negative charge, nucleic acids are not efficiently taken up by cells, and thus, their clinical potential remains limited so far. Therefore, various delivery vehicles have been designed to assist the cellular uptake of nucleic acids. Among these, cell-penetrating peptides (CPPs) have gained increasing popularity as efficient and nontoxic delivery vectors. CPPs can be coupled to nucleic acids either by covalent or noncovalent association. Noncovalent coupling, which is based on the formation of nanoparticle-like nanocomplexes (NP), has received much attention in recent years, and the number of studies employing the strategy is explosively increasing due to the high therapeutic potential. However, the properties of CPP/nucleic acid NPs have not been characterized in sufficient detail yet. We performed a comprehensive analysis of the size and morphology of nucleic acid nanoparticles with novel transfection peptides, PepFects (PFs) and NickFects (NFs), using negative staining transmission electron microscopy (TEM). In addition, we examined whether the attachment of fluorescence or (nano)gold label to nucleic acid affects the nanocomplex formation or its morphology. We demonstrated that transportan-10-based new generation CPPs from PF and NF families condense nucleic acids to NPs of homogeneous size and shape. The size and shape of assembled nanoparticles depend on the type of the complexed nucleic acid and the sequence of the used peptide, whereas the label on the nucleic acid does not influence the gross characteristics of formed NPs.

Peptide self-assembly for nanomaterials: the old new kid on the block

Peptide self-assembly is an increasingly attractive tool for nanomaterials. Perfected in biology peptide self-assembling systems have impacted on nearly any conceivable nanomaterial type. However, with all the information available to us commercialisation of peptide materials remains in its infancy. In an attempt to better understand the reasons behind this shortcoming we categorise peptide self-assembled materials in relation to their non-peptide counterparts. A particular emphasis is placed on the versatility of peptide self-assembly in terms of modularity, responsiveness and functional diversity, which enables direct comparisons with more traditional material chemistries.