# Cell-Derived Nanocarriers of Apoptotic Bodies with an Antimicrobial Peptide for Targeting Intracellular S. aureus Infections

## TL;DR

Researchers developed a new nanocarrier to deliver an antimicrobial peptide to treat hard-to-reach Staphylococcus aureus infections inside cells.

## Contribution

This is the first study to develop a ReApoBD-AMP formulation for targeting intracellular S. aureus infections.

## Key findings

- ReApoBDs achieved high encapsulation efficiency (∼70%) and improved intracellular delivery of BotrAMP14.
- The nanoformulation reduced intracellular bacterial loads with lower cytotoxicity than free peptide.
- In vivo experiments showed ReApoBD-BotrAMP14 reduced dermonecrosis and SCV prevalence more effectively than conventional treatments.

## Abstract

Intracellular infections
caused by Staphylococcus
aureus are challenging due to their ability to evade
host defenses, through the development of small colony variants (SCVs)
that are resistant to conventional therapies. This study yielded and
evaluated size-remodeled apoptotic bodies (ReApoBDs) as cell-derived
nanocarriers for the targeted delivery of BotrAMP14, an antimicrobial
peptide, to treat S. aureus-infected
macrophages. ReApoBDs demonstrated high encapsulation efficiencies
(∼70%), biocompatibility, sustained drug release over 12 h,
colloidal stability, and improved intracellular delivery. The ReApoBDs-BotrAMP14
nanoformulation reduced intracellular bacterial loads while exhibiting
lower cytotoxicity compared to the free peptide. Moreover, in vivo experiments demonstrated that ReApoBD-BotrAMP14
reduced dermonecrosis by 31.7% and SCV prevalence by 72.9%, more effectively
than conventional treatments in a skin abscess model. Finally, the
positive correlation between cell viability and bacterial survival
highlights the challenge of designing treatments that effectively
eliminate intracellular bacteria while preserving host cell integrity.
As the first study to develop a ReApoBD-AMP formulation, these findings
position ReApoBD-BotrAMP14 as a groundbreaking platform for treating
persistent intracellular infections.