The need exists to improve sensitivity of detection of toxic pollutants and pathogenic microorganisms, ensuring food and water safety. Developing methods that would increase antibody binding surface area and/or improve the sampling process by specifically concentrating the analyte of interest from the diluted extracted food sample would increase the chances of finding and detecting food pathogens and their toxins. Our approach to improve sensitivity was to generate high surface nanofibrous membranes with covalently attached molecular recognition elements (MREs, e.g. antibodies and peptides) for the selective capture of target analytes through the use of electrospinning. Electrospinning is a process by which high static voltages are used to produce an interconnected membrane-like web of small fibers with diameters ranging from 50-1000 nanometers. These nanofibrous membranes can have surface areas approximately one to two orders of magnitude higher than those found in continuous films. The association of MREs with electrospun fibers presents the opportunity for developing both biosensor detection platforms with increased surface area and membrane concentrators. It is expected that the available surface area demonstrated by this technique will provide increased sensitivity, capture efficiency and fast response time in sensing applications. Antibodies and peptide-based receptors were selectively immobilized onto these nanoporous membranes for bioaffinity capture. Initial results involving fluorescent and chemiluminescent imaging for quantifying attachment and activity in association with the electrospinning process will be discussed.
Antimicrobial peptides (AMPs) have been discovered in insects, mammals, reptiles, and plants to protect against
microbial infection. Many of these peptides have been isolated and studied exhaustively to decipher the molecular
mechanisms that impart protection against infectious bacteria, fungi, and viruses. Unfortunately, the molecular
mechanisms are still being debated within the scientific community but valuable clues have been obtained through
structure/function relationship studies<sup>1</sup>. Biophysical studies have revealed that cecropins, isolated from insects and pigs,
exhibit random structure in solution but undergo a conformational change to an amphipathic α-helix upon interaction
with a membrane surface<sup>2</sup>. The lack of secondary structure in solution results in an extremely durable peptide able to
survive exposure to high temperatures, organic solvents and incorporation into fibers and films without compromising
antibacterial activity. Studies to better understand the antimicrobial action of cecropins and other AMPs have provided
insight into the importance of peptide sequence and structure in antimicrobial activities. Therefore, enhancing our
knowledge of how peptide structure imparts function may result in customized peptide sequences tailored for specific
applications such as targeted cell delivery systems, novel antibiotics and food preservation additives. This review will
summarize the current state of knowledge with respect to cell binding and antimicrobial activity of AMPs focusing
primarily upon cecropins.