Antimicrobial Peptide Aerogels As An Inhalable Therapy For Drug-Resistant Tuberculosis
Open Access
- Author:
- Klein, Bailey
- Area of Honors:
- Biomedical Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Scott H Medina, Thesis Supervisor
Jian Yang, Thesis Honors Advisor
Justin Lee Brown, Faculty Reader - Keywords:
- Antimicrobial Peptides
Aerogels
Peptides
Tubercuosis
Mycobacterium Tuberculosis - Abstract:
- Antimicrobial peptides (AMPs) are cationic and amphiphilic molecules that are capable of selectively killing bacterial pathogens via membrane disruption. In this work, I focus on AMPs that kill Mycobacterium tuberculosis (Mtb), which is the causative agent of tuberculosis (TB). We hypothesized that by taking advantage of the membrane permeabilization effects of AMPs we can increase the efficacy of conventional TB antibiotics. In this study, we investigated the synergy between four AMPs and four TB antibiotics including rifampicin, moxifloxacin, ethionamide, and isoniazid. Ideal synergistic combinations are formed into aerosolize nanogels (aerogels) to form an inhalable therapy for drug resistant TB. Peptides are prepared through solid phase synthesis and are further purified using reverse phase liquid chromatography. Antibiotic and AMP synergy was measured by performing combinatorial assays with attenuated cultures of Mtb (H37Ra). Synergy is determined by calculating the fractional inhibitory concentration index of each combination. Aerogels are formed by using a previously optimized electrospray technique. The method involves loading hyaluronic acid (HA) into a syringe and spraying it through a large electric field into a bath of peptide. The AMPs and HA then form an electrostatic cross assembly and form the aerogels. The size of the aerogels is determined using dynamic light scattering. From the combinatorial assays, it was found that MAD1 and Moxifloxacin are a synergistic pairing while the other fifteen combinations were either additive or indifferent. I hypothesize this result is from MAD1’s ability to permeabilize the membrane allowing for Moxifloxacin to more easily diffuse into the bacterium. In addition, all aerogel formations resulted in a diameter the size of 1 micrometer, which is the ideal size for an inhalable therapy.