Polymer-coated gold nanoparticles and polymeric nanoparticles as nanocarrier of the BP100 antimicrobial peptide through a lung surfactant model

Abstract

Pneumonia is caused by microorganisms that settle in the lungs, which may reach the pulmonary alveoli and cause respiratory failure. Antibiotic treatments are the most used, although their use may not be efficient due to bacterial resistance. The antimicrobial peptide BP100 is a promising candidate for a new antibiotic due to its low susceptibility to bacterial resistance. It can be most effective when carried with gold nanoparticles (AuNPs) and polymer coatings for topical use. The goal of this work is to evaluate the effect of the transposition of the BP100 peptide carried on a gold nanoparticle coated with three types of polymers (polyethylene glycol (PEG), polystyrene (PS) and polyethylene glycol-block-polystyrene (PEG-b-PS)) using a lung surfactant (LS) model. The Gibbs free energies for nanoparticle transpositions are performed using coarse-grained molecular dynamics (CGMD) and umbrella sampling. The results demonstrate that the process is spontaneous for the BP100 adsorbed on the AuNPs encapsulated with PEG. The PEG effect on the AuNP-BP100-PEG system works as a protection method or a ligand competition for BP100 transposition. However, it is observed that the BP100-PEG nanoparticle breaks up as reaching the aqueous phase. Then, BP100 migrates to the polar heads region of the negatively charged phospholipids. It is possible to evaluate the effects of nanocarriers on the LS model. Besides that it is suggested the feasibility of applying antimicrobial peptides carried on PEG capped AuNPs for possible treatments of lung diseases.