Current Pharmaceutical Biotechnology - Volume 12, Issue 8, 2011

Peptides own a high potential in the field of cancer because of their high target selectivity and vast applications. Tumor targeted drug delivery has increasingly become an essential step in anticancer therapies as conventional chemotherapies are accompanied with several limitations such as adverse effects and development of drug resistance. Among many targeting approaches, peptide-based carrier systems have contribut Read More

This review focuses on the application of two classes of peptides, i.e., self-assembling peptides (SAPs) and cell-targeting peptides (CTPs), in the development of nanocarrier delivery systems. Self-assembling peptides are emerging in a wide range of biomedical and bioengineering applications and fall into several classes, including peptide amphiphilies, bolaamphiphile peptides, cyclic peptides, and ionic complement Read More

Peptides have emerged as important therapeutics that are being rigorously tested in angiogenesis-dependent diseases due to their low toxicity and high specificity. Since the discovery of endogenous proteins and protein fragments that inhibit microvessel formation (thrombospondin, endostatin) several peptides have shown promise in pre-clinical and clinical studies for cancer. Peptides have been derived from thrombospondin, c Read More

Drug discovery and development are intense, lengthy and interdisciplinary processes. Traditionally, drugs were discovered by synthesizing compounds in time-consuming multi-step experimental investigations followed by in vitro and in vivo biological screening. Promising candidates were then further studied for their pharmacokinetic properties, metabolism and potential toxicity. Today, the process of drug discovery h Read More

Various peptide sequences have been discovered by selecting peptide-phage display libraries in vitro against specific receptors or in vivo in tumor-bearing animals. One class of these peptides is characterized by the presence of Asn- Gly-Asp (NGR), a structural motif that can recognize the endothelium and other cells of neoangiogenic vessels. Because of this property these peptides have been used by several investigators t Read More

pH-sensitive liposomes undergo rapid destabilization under mildly acidic conditions such as those found in endocytotic vesicles. Though this makes them promising drug carriers, their application is limited due to their rapid clearance from circulation by the reticulo-endothelial system. Researchers have therefore used pH-sensitive liposomes that are sterically stabilized by polyethylene glycol (PEG) molecules (stealth lipo Read More

Targeted therapy may be a promising approach against cancer because its focus of attention is to enhance the efficacy and to reduce the side effects of antitumor agents through high selectivity. One of targeted strategies is to use tumor- specific ligands as targeting moieties to carry drugs into tumor cells, and use the receptors that expressed on tumor cells as target sites to bind with peptide ligands. The fact that the distrib Read More

Until recently, most research efforts aimed at developing anti-cancer tools were focusing on small molecules. Alternative compounds are now being increasingly assessed for their potential anti-cancer properties, including peptides and their derivatives. One earlier limitation to the use of peptides was their limited capacity to cross membranes but this limitation was alleviated with the characterization of cell-permeable seq Read More

Anticancer drug delivery has been hindered due to cell membrane permeability and the lack of a selective marker for tumor cells. Cell permeability is related to the bioavailability of drugs and has therefore been considered to be an essential step for achieving therapeutic efficacy. While different types of transporters currently exist, cell penetrating peptides (CPPs) have become one of the most popular and effective tools for intra Read More

From a pragmatic perspective, we are all familiar with the clinical need for antibiotics, and many of us understand the role that antibiotics play in maintaining a safe and abundant food supply. However, the study of antibiotics has also contributed to our fundamental understanding of microbial physiology, which has given us wonderful insights into our own physiology. Antimicrobial “mechanisms of action” and antimicrobial resist Read More

Antimicrobial peptides (AMPs) produced by a wide variety of organisms are major actors of the host defense systems against invading pathogenic microorganisms. These peptides exhibit a broad spectrum of action against bacteria, yeasts, fungi, protozoa and viruses. It is widely believed that a large part of their antimicrobial effect derives from direct interactions with the lipid membrane surrounding the target cells, causing its Read More

Glycopeptide antibiotics, vancomycin and teicoplanin, inhibit cell wall synthesis in Gram-positive bacteria by interacting with peptidoglycan D-Ala-D-Ala peptide stem termini of the pentapeptide side chains of the peptidoglycan precursors. In glycopeptide-resistant bacteria, multiresistance poses major therapeutic problems. New potent antibacterial agents are needed to combat these resistance problems, resulting in the explosio Read More

Bacteriocins are ribosomally synthesized (poly)peptides produced by almost all prokaryotic lineages. Bacteriocins from lactic acid bacteria (LAB) and bacteriocin-producer probiotic organisms have been thoroughly studied due to their wide spectra of action, the long-term use in food fermentations and the consideration of these microorganisms as beneficial for human beings. Most of the studies on the biotechnologic Read More

Lantibiotics are ribosomally synthesized, post-translationally modified, peptide antibiotics containing unusual amino acids such as dehydrated amino acids and lanthionine. These unusual amino acids impose conformational constraints on the peptide and contribute to the biological activity and high physicochemical stability of lantibiotics. Recent researches on the modification enzymes responsible for dehydration and cyclization Read More

Lantibiotics are posttranslationally modified antimicrobial peptides produced by some Gram-positive bacteria. After secreting mature lantibiotics, producer cells are at risk for self-destruction. Lantibiotic-producing strains express immunity protein(s) to protect cells against their own products. To date, several types of immunity proteins with diverse structures and functions have been identified. These proteins consist of ABC tra Read More

Staphylococcus aureus (S. aureus) is an important foodborne and environmental pathogen that can produce toxins in foods and cause infections in soft tissues. S. aureus that have developed resistance to the conventional antimicrobials are commonly called Methicillin-Resistant Staphylococcus aureus (MRSA) and Vancomycin-Resistant S. aureus (VRSA). Their prevalence is believed to be due to the widespread use of antibiotics. Read More

Invasive fungal infections are a serious threat to public health, particularly to people with compromised or suppressed immunity. Although the current antifungal therapies have been significantly improved, the outcome is still far from satisfactory, partly due to the limited number of classes of clinically available antifungals, the development of resistance to current antifungals, and the challenges of proper and early diagnosis Read More

Many cationic peptides with antimicrobial properties have been isolated from bacteria, fungi, plants, and animals. These peptides vary in molecular size, potency and spectra of activities. This report surveyed the literature to highlight the peptides that have antifungal activity and greatest potential for development as new therapeutic agents. Thus, to be included in the evaluation, each peptide had to fulfil the following crite Read More