A global review on short peptides: frontiers and perspectives

Peptides are fragments of proteins that carry out biological functions. They act as signaling entities via all domains of life and interfere with protein-protein interactions, which are indispensable in bio-processes. Short peptides include fundamental molecular information for a prelude to the symphony of life. They have aroused considerable interest due to their unique features and great promise in innovative bio-therapies. This work focusing on the current state-of-the-art short peptide-based therapeutical developments is the first global review written by researchers from all continents, as a celebration of 100 years of peptide therapeutics since the commencement of insulin therapy in the 1920s. Peptide “drugs” initially played only the role of hormone analogs to balance disorders. Nowadays, they achieve numerous biomedical tasks, can cross membranes, or reach intracellular targets. The role of peptides in bio-processes can hardly be mimicked by other chemical substances. The article is divided into independent sections, which are related to either the progress in short peptide-based theranostics or the problems posing challenge to bio-medicine. In particular, the SWOT analysis of short peptides, their relevance in therapies of diverse diseases, improvements in (bio)synthesis platforms, advanced nano-supramolecular technologies, aptamers, altered peptide ligands and in silico methodologies to overcome peptide limitations, modern smart bio-functional materials, vaccines, and drug/gene-targeted delivery systems are discussed

Non-biological gene carriers designed for overcoming the major extra- and intracellular hurdles in gene delivery, an updated review

Gene therapy as a modern therapeutic approach has not yet advanced to a globally-approved therapeutic approach. Lack of adequate reliable gene delivery system seems to be one of the major reasons from the pharmaceutical biotechnology point of view. Main obstacles delaying successful application of human gene therapy are presented in this review. The unique advantages of non-biological gene carriers as compared to their biological counterparts make them ideal alternatives for  overcoming extra- and intracellular barriers in a more safely manner. We, therefore, highlight the significant contributions in non-biological gene delivery and favorable characteristics of different design attitudes with focus on in vivo approaches. Bypassing the rapid extracellular enzymatic degradation of genetic materials is covered in extracellular segment of this review with emphasis on PEGylated and targeted formulations. The successful approaches to pave the rest of the way from cellular uptake to intracellular transfer and gene expression of unpacked DNA are also discussed. From these approaches, we emphasize more on optimization of cationic-based polymers and dendrimers, developing newly designed membrane-effective components, and adjusting the hydrophilic-hydrophobic balance of the synthesized vector

Gene Transfer Enhancement by Alkylcarboxylation of Poly(propylenimine)

Abstract Among synthetic carriers, dendrimers with the more flexible structure have attracted a great deal of researchers’ attention in the field of gene delivery. Followed by the promising results upon hydrophobic modification on polymeric structures in our laboratory, alkylcarboxylated poly (propylenimine)-based carriers were synthesized by nucleophilic substitution of amines with alkyl moieties and were further characterized for their physicochemical and biological characteristics for plasmid DNA delivery. Although not noticeably effective gene transfer activity for hexanoate- and hexadecanoate-modified series was observed, but alkylation by decanoic acid significantly improved the transfection efficiency of the final constructs up to 60 fold in comparison with unmodified poly(propylenimine) (PPI). PPI modified by 10-bromodecanoic acid at 50% grafting, showed significantly higher gene expression at c/p ratio of 2 compared to Superfect as positive control.  Overall, modification of PPI with 50% primary amines grafting with 10-bromodecanoic acid could increase the transfection efficiency which is occurred at lower c/p ratio when compared to Superfect, i.e. less amount of modified vector is required to exhibit the same efficiency as Superfect. Therefore, the obtained constructs seem to be safer carriers for long-term gene therapy applications

P53-Derived peptides conjugation to PEI: an approach to producing versatile and highly efficient targeted gene delivery carriers into cancer cells

<p><b><i>Objectives</i>:</b> Targeted delivery of cytotoxic drugs or therapeutic antisense RNAs into specific cells is a major bottleneck in cancer therapy. To overcome this problem and improve the specificity for cancer cells, we describe a new-targeted delivery system using p53-derived peptides, namely PNC 27 and PNC 28. These peptides target HDM-2 on the surface of cancer cells. HDM-2 is overexpressed on the surface of cancerous cells, but not present on the untransformed cells.</p> <p><b><i>Methods</i>:</b> To determine HDM-2-expressing cells, we used immunocytochemistry and flow cytometry analysis on nine cell lines including MCF-7 and NIH-3t3. Conjugation of peptides to vectors was confirmed using reverse-phase high-pressure liquid chromatography (RP-HPLC). Physicochemical properties of vector/DNA complexes including particle size, surface charge and DNA condensation ability were determined. In transfection studies, three plasmids were used including luciferase, pEGFP and shRNA plasmid against Bcl-XL mRNA. The level of Bcl-XL expression was determined by real-time PCR and western blot techniques.</p> <p><b><i>Results</i>:</b> The results of gene delivery and shRNA-based gene silencing studies indicated that conjugation of PNC peptides could enhance gene delivery efficiently with high-targeted activity exclusively into cancer cells.</p> <p><b><i>Conclusion</i></b>: Our results strongly indicated that this targeting system could be utilized as an efficient targeting method for most cancer cells.</p