Discipline: Biological Sciences
Ron-esha Blake - Alabama State University
A current pressing concern is the resistance of bacterial microorganisms to available antibiotics. Nanoparticles in recent years have been progressively used as a sufficient substitute to antibiotics. Even so, antimicrobial peptides due to their antibacterial activity against multi-drug resistant bacteria have also gained much attention. However, their stability is a major concern. In the present study, we hypothesize that the encapsulation of antimicrobial peptide TP557 in Polylactic-co-glycolic acid (PLGA) will provide stabilized degradation of PLGA, releasing peptide TP557 at a controlled rate and may exhibit better antimicrobial activity. Methods: First we determined the antibacterial effect of antimicrobial peptide 557 (TP557) from Therapeutic Peptides Inc.® against Staphylococcus aureus and Escherichia coli using minimum inhibitory concentration (MIC) assay, and growth curve analysis of Staphylococcus aureus and Escherichia coli exposed to peptide TP557. The encapsulation efficiency of the peptide incorporation into PLGA will be determined and the antibacterial effect of the encapsulated antimicrobial peptide will be evaluated using molecular, microbiological and microscopic methods. Results: For both bacteria, the data showed that the MIC of the peptide against Staphylococcus aureus and Escherichia coli was 7.81 µg/ml. The sequential monitoring of the growth of the bacteria exposed to TP557 showed that the bacterial growth was inhibited in a time and concentration dependent manner.
Conclusions: This information will be beneficial for future research of encapsulation of the peptide. PLGA is advantageous as it is biocompatible, biodegradable, and provides continued release.
References:  LM Durso and KL Cook, Impacts of antibiotic use in agriculture: What are the benefits and risks?, Current opinion in microbiology, 19C, 37-44, 2014.
 NK Brogden , KA Brogden 2011 Will new generations of modified antimicrobial peptides improve their potential as pharmaceuticals? International journal of antimicrobial agents 38 217-225
 KA Brogden, M Ackermann, PB McCray , Jr., Bf Tack 2003 Antimicrobial peptides in animals and their role in host defenses International journal of antimicrobial agents 22 465-478
Funder Acknowledgement(s): This work was supported by US Dept. of Education, The Minority Science and Engineering Improvement Program (MSEIP) (P120A150008) to Komal Vig (PD) and by NSFCREST (HRD-1241701) to Shree S. Singh (PI).
Faculty Advisor: Shreekumar Pillai, Spillai@alasu.edu
Role: Bacterial growth, MIC, growth curve and encapsulation was conducted by myself, Ron-esha Blake