The fluorination effect on the transfection efficacy of cell penetrating peptide complexes.

Cell penetrating peptides (CPPs) have been used as alternative delivery vectors to translocate therapeutic cargo molecules across cell membranes. One example of CPPs is the dTAT peptide, which has shown great promise in the design of highly efficient and low-cytotoxic gene vectors when condensed via "soft" calcium cross links. Here, we investigated the effect of fluorination on the formulation of dTAT complexes and explored their potential for pDNA delivery to cells.

Calcium enhances gene expression when using low molecular weight poly-l-lysine delivery vehicles.

Four molecular weights of poly-l-lysine (PLL) [1000-5000 Da, 1500-8000 Da, 4000-15,000 Da and 15,000-30,000 Da] and three molecular weights of polyethyleneimine (PEI) [800 Da, 2,000 Da, and 25,000 Da] were used to systematically study the effect of calcium (Ca) to improve transfection efficiency of polyelectrolyte complexes. Complexes made using different molecular weights of PLL or PEI polymer showed clear differences in the levels of gene expression in the presence and absence of calcium chloride when tested using A549 human lung carcinoma cells. Complexes formed from PLL or PEI 800 Da were exhibited negligible expression of pDNA according to a luciferase reporter assay.

Synthesis and evaluation of the biostability and cell compatibility of novel conjugates of nucleobase, peptidic epitope, and saccharide.

This article reports the synthesis of a new class of conjugates containing a nucleobase, a peptidic epitope, and a saccharide and the evalution of their gelation, biostability, and cell compatibility. We demonstrate a facile synthetic process, based on solid-phase peptide synthesis of nucleopeptides, to connect a saccharide with the nucleopeptides for producing the target conjugates. All the conjugates themselves (1-8) display excellent solubility in water without forming hydrogels.

Synthesis of novel conjugates of a saccharide, amino acids, nucleobase and the evaluation of their cell compatibility.

This article reports the synthesis of a novel type of conjugate of three fundamental biological build blocks (i.e., saccharide, amino acids, and nucleobase) and their cell compatibility.

DNA complexed with TAT peptide and condensed using calcium possesses unique structural features compared to PEI polyplexes.

Complexes of the TAT peptide with plasmid DNA (pDNA) show unusually high transfection efficiency when condensed via "soft" calcium cross links. In this study, we characterize the structure of pDNA within TAT complexes and compare it with that of branched polyethylenimine (PEI, 25 kDa) complexes. Dynamic light scattering (DLS), second derivative ultraviolet absorption spectroscopy, extrinsic dye fluorescence, Fourier transform infrared (FTIR) spectroscopy, circular dichroism (CD) spectroscopy and differential scanning calorimetry (DSC) were employed to access various aspects of the structure of the pDNA.

Intratracheal administration of a nanoparticle-based therapy with the angiotensin II type 2 receptor gene attenuates lung cancer growth.

Targeted gene delivery, transfection efficiency, and toxicity concerns remain a challenge for effective gene therapy. In this study, we dimerized the HIV-1 TAT peptide and formulated a nanoparticle vector (dTAT NP) to leverage the efficiency of this cell-penetrating strategy for tumor-targeted gene delivery in the setting of intratracheal administration. Expression efficiency for dTAT NP-encapsulated luciferase or angiotensin II type 2 receptor (AT2R) plasmid DNA (pDNA) was evaluated in Lewis lung carcinoma (LLC) cells cultured in vitro or in vivo in orthotopic tumor grafts in syngeneic mice.

Calcium condensed cell penetrating peptide complexes offer highly efficient, low toxicity gene silencing.

The development of short-interfering RNA (siRNA) offers new strategies for manipulating specific genes responsible for pathological disorders. Myriad cationic polymer and lipid formulations have been explored, but an effective, non-toxic carrier remains a major barrier to clinical translation. Among the emerging candidates for siRNA carriers are cell penetrating peptides (CPPs), which can traverse the plasma membrane and facilitate the intracellular delivery of siRNA.

Calcium condensed LABL-TAT complexes effectively target gene delivery to ICAM-1 expressing cells.

Targeted gene delivery using nonviral vectors is a highly touted scheme to reduce the potential for toxic or immunological side effects by reducing dose. In previous reports, TAT polyplexes with DNA have shown relatively poor gene delivery. The transfection efficiency has been enhanced by condensing TAT/DNA complexes to a small particle size using calcium.

Calcium condensation of DNA complexed with cell-penetrating peptides offers efficient, noncytotoxic gene delivery.

Drug delivery strategies using cell-penetrating peptides (CPPs) have been widely explored to improve the intracellular delivery of a large number of cargo molecules. Electrostatic complexation of plasmid DNA using CPPs has been less explored due to the relatively large complexes formed and the low levels of gene expression achieved when using these low-molecular-weight polycations as DNA condensing agents. Here, condensing nascent CPP polyplexes using CaCl(2) produced small and stable nanoparticles leading to gene expression levels higher than observed for control polyethylenimine gene vectors.

Controlling ligand surface density optimizes nanoparticle binding to ICAM-1.

During infection, pathogens utilize surface receptors to gain entry into intracellular compartments. Multiple receptor-ligand interactions that lead to pathogen internalization have been identified and the importance of multivalent ligand binding as a means to facilitate internalization has emerged. The effect of ligand density, however, is less well known.

Cationic surface modification of PLG nanoparticles offers sustained gene delivery to pulmonary epithelial cells.

Biodegradable polymeric nanoparticles are currently being explored as a nonviral gene delivery system; however, many obstacles impede the translation of these nanomaterials. For example, nanoparticles delivered systemically are inherently prone to adsorbing serum proteins and agglomerating as a result of their large surface/volume ratio. What is desired is a simple procedure to prepare nanoparticles that may be delivered locally and exhibit minimal toxicity while improving entry into cells for effectively delivering DNA.

"Soft" calcium crosslinks enable highly efficient gene transfection using TAT peptide.

Purpose: Typically, low molecular weight cationic peptides or polymers exhibit poor transfection efficiency due to an inability to condense plasmid DNA into small nanoparticles. Here, efficient gene delivery was attained using TAT/pDNA complexes containing calcium crosslinks.

Methods: Electrostatic complexes of pDNA with TAT or PEI were studied with increasing calcium concentration.

ICAM-1 targeting of doxorubicin-loaded PLGA nanoparticles to lung epithelial cells.

Interaction of leukocyte function associated antigen-1 (LFA-1) on T-lymphocytes and intercellular adhesion molecule-1 (ICAM-1) on epithelial cells controls leukocyte adhesion, spreading, and extravasation. This process plays an important role in leukocyte recruitment to a specific site of inflammation and has been identified as a biomarker for certain types of carcinomas. Cyclo-(1,12)-PenITDGEATDSGC (cLABL) has been shown to inhibit LFA-1 and ICAM-1 interaction via binding to ICAM-1.