Supplementation with ions enhances the efficiency of nucleic acid delivery with cell-penetrating peptides.

The successful delivery of therapeutic nucleic acids (NAs) into eukaryotic cells is essential for numerous biomedical applications, including gene therapy, gene silencing, and genome editing. Cell-penetrating peptides (CPPs) have claimed significant attention as delivery vehicles due to their inherent ability to penetrate cellular membranes and efficiently transport cargo, including NAs, into the cells. However, further optimization and a deeper understanding of underlying mechanisms are necessary for such transfection methods.

PepFect14 mediates the delivery of mRNA into human primary keratinocytes and .

mRNA-based vaccines and candidate therapeutics have great potential in various medical fields. For the delivery of mRNA into target cells and tissues, lipid formulations are often employed. However, this approach could cause the activation of immune responses, making it unsuitable for the treatment of inflammatory conditions.

Characterization of Uranyl (UO) Ion Binding to Amyloid Beta (Aβ) Peptides: Effects on Aβ Structure and Aggregation.

Uranium (U) is naturally present in ambient air, water, and soil, and depleted uranium (DU) is released into the environment via industrial and military activities. While the radiological damage from U is rather well understood, less is known about the chemical damage mechanisms, which dominate in DU. Heavy metal exposure is associated with numerous health conditions, including Alzheimer's disease (AD), the most prevalent age-related cause of dementia.

Choosing an Optimal Solvent Is Crucial for Obtaining Cell-Penetrating Peptide Nanoparticles with Desired Properties and High Activity in Nucleic Acid Delivery.

Cell-penetrating peptides (CPPs) are highly promising transfection agents that can deliver various compounds into living cells, including nucleic acids (NAs). Positively charged CPPs can form non-covalent complexes with negatively charged NAs, enabling simple and time-efficient nanoparticle preparation. However, as CPPs have substantially different chemical and physical properties, their complexation with the cargo and characteristics of the resulting nanoparticles largely depends on the properties of the surrounding environment, i.

Divalent Metal Ions Boost Effect of Nucleic Acids Delivered by Cell-Penetrating Peptides.

Cell-penetrating peptides (CPPs) are promising tools for the transfection of various substances, including nucleic acids, into cells. The aim of the current work was to search for novel safe and effective approaches for enhancing transfection efficiency of nanoparticles formed from CPP and splice-correcting oligonucleotide (SCO) without increasing the concentration of peptide. We analyzed the effect of inclusion of calcium and magnesium ions into nanoparticles on CPP-mediated transfection in cell culture.

Use of PepFect14 and siRNA for Targeted Gene Silencing in Human Embryonic Stem Cells.

The unique properties of human embryonic stem (hES) cells render them invaluable for many scientific and clinical endeavors. Wider application of hES cells requires a comprehensive understanding of their biology that can be dissected using RNA interference-based gene silencing. However, commonly used transfection methods to deliver nucleic acids into a cell often lead to differentiation of hES cells.

Development of CPP-Based Methods for Delivery of miRNAs into the Skin and Airways: Lessons from Cell Culture and Mouse Models.

microRNAs (miRNAs) have capacity to modulate numerous biological processes and therefore synthetic oligonucleotides mimicking or inhibiting particular miRNA have potential in the development of novel types of therapeutics. We have elaborated several methods for safe and efficient overexpression of miRNAs using self-forming nanocomplexes of PepFect or NickFect type of cell-penetrating peptides (CPPs) and oligonucleotides mimicking well-characterized anti-inflammatory miR-146a. We focus on chronic inflammatory diseases affecting epithelium, such as atopic dermatitis and asthma harnessing respective cell cultures and mouse models.

Internalisation and Biological Activity of Nucleic Acids Delivering Cell-Penetrating Peptide Nanoparticles Is Controlled by the Biomolecular Corona.

Nucleic acid molecules can be transferred into cells to alter gene expression and, thus, alleviate certain pathological conditions. Cell-penetrating peptides (CPPs) are vectors that can be used for transfecting nucleic acids as well as many other compounds. CPPs associate nucleic acids non-covalently, forming stable nanoparticles and providing efficient transfection of cells in vitro.

Dual role of the miR-146 family in rhinovirus-induced airway inflammation and allergic asthma exacerbation.

Rhinovirus (RV) infections are associated with asthma exacerbations. MicroRNA-146a and microRNA-146b (miR-146a/b) are anti-inflammatory miRNAs that suppress signaling through the nuclear factor kappa B (NF-κB) pathway and inhibit pro-inflammatory chemokine production in primary human bronchial epithelial cells (HBECs). In the current study, we aimed to explore whether miR-146a/b could regulate cellular responses to RVs in HBECs and airways during RV-induced asthma exacerbation.

NickFect type of cell-penetrating peptides present enhanced efficiency for microRNA-146a delivery into dendritic cells and during skin inflammation.

MicroRNAs (miRNAs) are post-transcriptional gene expression regulators with potential therapeutic applications. miR-146a is a negative regulator of inflammatory processes in both tissue-resident and specialized immune cells and may therefore have therapeutic effect in inflammatory skin diseases. PepFect (PF) and NickFect (NF) type of cell-penetrating peptides (CPPs) have previously been shown to deliver miRNA mimics and/or siRNAs into cell cultures and in vivo.

Deciphering the internalization mechanism of WRAP:siRNA nanoparticles.

Gene silencing mediated by double-stranded small interfering RNA (siRNA) has been widely investigated as a potential therapeutic approach for a variety of diseases and, indeed, the first therapeutic siRNA was approved by the FDA in 2018. As an alternative to the traditional delivery systems for nucleic acids, peptide-based nanoparticles (PBNs) have been applied successfully for siRNA delivery. Recently, we have developed amphipathic cell-penetrating peptides (CPPs), called WRAP allowing a rapid and efficient siRNA delivery into several cell lines at low doses (20 to 50 nM).

Enhancement of siRNA transfection by the optimization of fatty acid length and histidine content in the CPP.

Extracellular synthetic nucleic acids, such as siRNAs, are unable to reach their intended targets efficiently. Therefore, delivery methods such as cell-penetrating peptides (CPP), which increase their transport, could enhance the potency of siRNA as therapeutic agents. The CPP NickFect55 (NF55) is an efficient peptide-based delivery vector, which has been previously used to deliver plasmid DNA into cells in vivo.

Characterization of Peptide-Oligonucleotide Complexes Using Electron Microscopy, Dynamic Light Scattering, and Protease Resistance Assay.

Cationic peptides designed for cellular delivery of nucleic acid molecules form noncovalent nanocomplexes with negatively charged oligonucleotides (ON). The electrostatically associated complexes are further compacted by hydrophobic interactions yielding nanoparticles (NP) of homogeneous shape and size that are efficiently taken up by cells. The shape and size of NP often correlate with the biological activity of delivered ON inside cells; and the stability and accessibility of NP in biological fluids govern its circulation in organism and the cellular uptake.

Targeted gene silencing in human embryonic stem cells using cell-penetrating peptide PepFect 14.

Background: Human embryonic stem (hES) cells serve as an invaluable tool for research and future medicine, but their transfection often leads to unwanted side effects as the method itself may induce differentiation. On the other hand, RNA interference (RNAi)-based targeted gene silencing is a quick, cost-effective, and easy-to-perform method to address questions regarding the function of genes, especially when hypomorphic knockdowns are needed. Therefore, effective transfection method with minimal side effects is essential for applying RNAi to hES cells.

Arginine-Rich Cell-Penetrating Peptides Require Nucleolin and Cholesterol-Poor Subdomains for Translocation across Membranes.

Proficient transport vectors called cell-penetrating peptides (CPPs) internalize into eukaryotic cells mostly via endocytic pathways and facilitate the uptake of various cargo molecules attached to them. However, some CPPs are able to induce disturbances in the plasma membrane and translocate through it seemingly in an energy-independent manner. For understanding this phenomenon, giant plasma membrane vesicles (GPMVs) derived from the cells are a beneficial model system, since GPMVs have a complex membrane composition comparable to the cells yet lack cellular energy-dependent mechanisms.

Formulation of Stable and Homogeneous Cell-Penetrating Peptide NF55 Nanoparticles for Efficient Gene Delivery In Vivo.

Although advances in genomics and experimental gene therapy have opened new possibilities for treating otherwise incurable diseases, the transduction of nucleic acids into the cells and delivery in vivo remain challenging. The high molecular weight and anionic nature of nucleic acids require their packing into nanoparticles for the delivery. The efficacy of nanoparticle drugs necessitates the high bioactivity of constituents, but their distribution in organisms is mostly governed by the physical properties of nanoparticles, and therefore, generation of stable particles with strictly defined characteristics is highly essential.

Targeted deletion of RIC8A in mouse neural precursor cells interferes with the development of the brain, eyes, and muscles.

Autosomal recessive disorders such as Fukuyama congenital muscular dystrophy, Walker-Warburg syndrome, and the muscle-eye-brain disease are characterized by defects in the development of patient's brain, eyes, and skeletal muscles. These syndromes are accompanied by brain malformations like type II lissencephaly in the cerebral cortex with characteristic overmigrations of neurons through the breaches of the pial basement membrane. The signaling pathways activated by laminin receptors, dystroglycan and integrins, control the integrity of the basement membrane, and their malfunctioning may underlie the pathologies found in the rise of defects reminiscent of these syndromes.

Role of autophagy in cell-penetrating peptide transfection model.

Cell-penetrating peptides (CPPs) uptake mechanism is still in need of more clarification to have a better understanding of their action in the mediation of oligonucleotide transfection. In this study, the effect on early events (1 h treatment) in transfection by PepFect14 (PF14), with or without oligonucleotide cargo on gene expression, in HeLa cells, have been investigated. The RNA expression profile was characterized by RNA sequencing and confirmed by qPCR analysis.

Systemic Delivery of Folate-PEG siRNA Lipopolyplexes with Enhanced Intracellular Stability for In Vivo Gene Silencing in Leukemia.

Protection of small interfering RNA (siRNA) against degradation and targeted delivery across the plasma and endosomal membranes to the final site of RNA interference (RNAi) are major aims for the development of siRNA therapeutics. Targeting for folate receptor (FR)-expressing tumors, we optimized siRNA polyplexes by coformulating a folate-PEG-oligoaminoamide (for surface shielding and targeting) with one of three lipo-oligoaminoamides (optionally tyrosine-modified, for optimizing stability and size) to generate ∼100 nm targeted lipopolyplexes (TLPs), which self-stabilize by cysteine disulfide cross-links. To better understand parameters for improved tumor-directed gene silencing, we analyzed intracellular distribution and siRNA release kinetics.

Comparison of Peptide- and Lipid-Based Delivery of miR-34a-5p Mimic into PPC-1 Cells.

The microRNA (miRNA) microRNA-34a (miR-34a) regulates a number of genes involved in cell cycle control and is therefore considered to have a high therapeutic potential. MiR-34a expression is often downregulated in cancer cells and its restoration has been shown to exert a tumor-suppressive effect. However, effective and safe delivery of synthetic miRNA analogs into cancer cells remains a challenge.

RIC8A is essential for the organisation of actin cytoskeleton and cell-matrix interaction.

RIC8A functions as a chaperone and guanine nucleotide exchange factor for a subset of G protein α subunits. Multiple G protein subunits mediate various signalling events that regulate cell adhesion and migration and the involvement of RIC8A in some of these processes has been demonstrated. We have previously shown that the deficiency of RIC8A causes a failure in mouse gastrulation and neurogenesis - major events in embryogenesis that rely on proper association of cells with the extracellular matrix (ECM) and involve active cell migration.

Saturated Fatty Acid Analogues of Cell-Penetrating Peptide PepFect14: Role of Fatty Acid Modification in Complexation and Delivery of Splice-Correcting Oligonucleotides.

Modifying cell-penetrating peptides (CPPs) with fatty acids has long been used to improve peptide-mediated nucleic acid delivery. In this study we have revisited this phenomenon with a systematic approach where we developed a structure-activity relationship to describe the role of the acyl chain length in the transfection process. For that we took a well-studied CPP, PepFect14, as the basis and varied its N-terminal acyl chain length from 2 to 22 carbons.

Cell-penetrating peptides recruit type A scavenger receptors to the plasma membrane for cellular delivery of nucleic acids.

Scavenger receptors (SRs) are a large family of multifunctional receptors that are involved in a range of physiologic and pathologic processes. The ability of class A scavenger receptors (SR-As) to bind anionic ligands facilitates the internalization of negatively charged cell-penetrating peptide (CPP)-nucleic acid nanocomplexes and thus makes them attractive targets for delivery of various nucleic acids. Recently, we demonstrated that SR-A3 and SR-A5 are recruited from intracellular membranes to the plasma membrane after incubation with PepFect 14-splice-switching oligonucleotide complexes.

Optimization of in vivo DNA delivery with NickFect peptide vectors.

As the field of gene therapy progresses, an increasingly urgent need has arisen for efficient and non-toxic vectors for the in vivo delivery of nucleic acids. Cell-penetrating peptides (CPP) are very efficient transfection reagents in vitro, however, their application in vivo needs improvement. To enhance in vivo transfection we designed various CPPs based on previous knowledge of internalization studies and physiochemical properties of NickFect (NF) nanoparticles.