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.

Enhancing Cellular Uptake of Native Proteins through Bio-Orthogonal Conjugation with Chemically Synthesized Cell-Penetrating Peptides.

The potential for native proteins to serve as a platform for biocompatible, targeted, and personalized therapeutics in the context of genetic and metabolic disorders is vast. Nevertheless, their clinical application encounters challenges, particularly in overcoming biological barriers and addressing the complexities involved in engineering transmembrane permeability. This study is dedicated to the development of a multifunctional nanoentity in which a model therapeutic protein is covalently linked to a cell-penetrating peptide, NickFect 55, with the objective of enhancing its intracellular delivery.

A Method for Using Cell-Penetrating Peptides for Loading Plasmid DNA into Secreted Extracellular Vesicles.

The low bioavailability and high toxicity of plasmid DNA (pDNA)-based therapeutics pose challenges for their in vivo application. Extracellular vesicles (EVs) have great potential to overcome these limitations, as they are biocompatible native cargo carriers. Various methods for loading pDNA into EVs, including electroporation, sonication, and co-incubation, have been previously investigated, but their success has been questionable.

The Development of Cell-Penetrating Peptides for Efficient and Selective In Vivo Expression of mRNA in Spleen Tissue.

mRNA-based therapeutics are presently one of the nucleic acid-based therapeutics with a high potential for extraordinary success as preventive vaccines. Current applications with mRNA therapeutics rely on lipid nanoparticle (LNP) mediated delivery of nucleic acids. In order to achieve the transition from preventive to therapeutic vaccines, there is a challenge of delivering the mRNA into non-hepatic tissues, especially into lymphoid tissues such as the spleen and lymph nodes.

Modification of the Linker Amino Acid in the Cell-Penetrating Peptide NickFect55 Leads to Enhanced pDNA Transfection for In Vivo Applications.

Despite numerous efforts over the last three decades, nucleic acid-based therapeutics still lack delivery platforms in the clinical stage. Cell-penetrating peptides (CPPs) may offer solutions as potential delivery vectors. We have previously shown that designing a "kinked" structure in the peptide backbone resulted in a CPP with efficient in vitro transfection properties.

Aggregation Limiting Cell-Penetrating Peptides Derived from Protein Signal Sequences.

Alzheimer's disease (AD) is the most common neurodegenerative disease (ND) and the leading cause of dementia. It is characterized by non-linear, genetic-driven pathophysiological dynamics with high heterogeneity in the biological alterations and the causes of the disease. One of the hallmarks of the AD is the progression of plaques of aggregated amyloid-β (Aβ) or neurofibrillary tangles of Tau.

Approaches for evaluation of novel CPP-based cargo delivery systems.

Cell penetrating peptides (CPPs) can be broadly defined as relatively short synthetic, protein derived or chimeric peptides. Their most remarkable property is their ability to cross cell barriers and facilitate the translocation of cargo, such as drugs, nucleic acids, peptides, small molecules, dyes, and many others across the plasma membrane. Over the years there have been several approaches used, adapted, and developed for the evaluation of CPP efficacies as delivery systems, with the fluorophore attachment as the most widely used approach.

Predicting Transiently Expressed Protein Yields: Comparison of Transfection Methods in CHO and HEK293.

Therapeutic proteins are currently at the apex of innovation in pharmaceutical medicine. However, their industrial production is technically challenging and improved methods for transient transfection of mammalian cell cultures are necessary. We aimed to find a fast, microliter-scale transfection assay that allows the prediction of protein expression in the transient production settings.

Amyloid-like Self-Assembly of a Hydrophobic Cell-Penetrating Peptide and Its Use as a Carrier for Nucleic Acids.

Cell-penetrating peptides (CPPs) are a topical subject potentially exploitable for creating nanotherapeutics for the delivery of bioactive loads. These compounds are often classified into three major categories according to their physicochemical characteristics: cationic, amphiphilic, and hydrophobic. Among them, the group of hydrophobic CPPs has received increasing attention in recent years due to toxicity concerns posed by highly cationic CPPs.

Endpoint and Kinetic Approaches for Assessing Transfection Efficacy in Mammalian Cell Culture.

The efficacy of transfection reagents and nanoparticles is often assessed by measuring levels of expressed reporter protein. Fluorescence and luminescence based assays provide sensitive, quantifiable and repeatable approaches. The genes expressing reporter protein can be integrated into the cells to create stable reporter cell lines or can be expressed from a transfected plasmid.

Cell-Penetrating Peptide and siRNA-Mediated Therapeutic Effects on Endometriosis and Cancer In Vitro Models.

Gene therapy is a powerful tool for the development of new treatment strategies for various conditions, by aiming to transport biologically active nucleic acids into diseased cells. To achieve that goal, we used highly potential delivery vectors, cell-penetrating peptides (CPPs), as oligonucleotide carriers for the development of a therapeutic approach for endometriosis and cancer. Despite marked differences, both of these conditions still exhibit similarities, like excessive, uncoordinated, and autonomous cellular proliferation and invasion, accompanied by overlapping gene expression patterns.

Cell-Penetrating Peptides Predicted From CASC3, AKIP1, and AHRR Proteins.

Peptides can be used as research tools and for diagnostic or therapeutic applications. Peptides, alongside small molecules and antibodies, are used and are gaining further interest as protein-protein interaction (PPI) modulators. Peptides have high target specificity and high affinity, but, unlike small molecule modulators, they are not able to cross the cell membranes to reach their intracellular targets.

Approaches for the discovery of new cell-penetrating peptides.

: The capability of cell-penetrating peptides (CPP), also known as protein transduction domains (PTD), to enter into cells possibly with an attached cargo, makes their application as delivery vectors or as direct therapeutics compelling. They are generally biocompatible, nontoxic, and easy to synthesize and modify. Three decades after the discovery of the first CPPs, ~2,000 CPP sequences have been identified, and many more predicted.

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.

Tumor gene therapy by systemic delivery of plasmid DNA with cell-penetrating peptides.

Gene therapy is a prospective strategy for treating cancer. However, finding efficient and tumor-specific gene delivery vectors remains an issue. Tumor responsive cell-penetrating peptide (CPP) PepFect144 (PF144) has previously been shown to deliver reporter gene encoding plasmid DNA specifically into tumors upon systemic administration, but its capability to reduce tumor growth has not yet been evaluated.