Antibiotic loaded solid lipid nanoparticles target bacteria in a pyogenic spondylitis rat model

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Infectious Diseases

Background:

• Pyogenic spondylitis requires prolonged high-dose antibiotic therapy.
• Current treatments face challenges in bacterial targeting and efficacy.
• Novel drug delivery systems are needed to enhance therapeutic outcomes.

Purpose of the Study:

• To develop and characterize novel solid lipid nanoparticles (SLNs) loaded with ampicillin (AMP) and functionalized with LL-37 peptide.
• To evaluate the enhanced antibacterial activity, bacterial-targeting capability, and therapeutic efficacy of these modified nanoparticles (LL-37@AMP-SLNs) against pyogenic spondylitis.

Main Methods:

• Preparation and characterization of ampicillin-loaded SLNs (AMP-SLNs) and LL-37 functionalized AMP-SLNs (LL-37@AMP-SLNs).
• Physicochemical analysis including particle size, zeta potential, morphology, and drug release kinetics.
• In vitro evaluation of antibacterial activity and bacterial targeting using Enterococcus faecalis-infected cells.
• In vivo assessment of therapeutic efficacy in a rat model of pyogenic spondylitis.

Main Results:

• LL-37@AMP-SLNs showed increased particle size and sustained ampicillin release over four days.
• Enhanced antibacterial activity and improved bacterial targeting were observed compared to AMP-SLNs and free AMP.
• LL-37@AMP-SLNs effectively inhibited bacterial growth by targeting bacterial cell walls and membranes.
• In vivo studies demonstrated reduced bacterial burden and improved therapeutic outcomes in the pyogenic spondylitis rat model.

Conclusions:

• LL-37@AMP-SLNs represent a promising therapeutic strategy for pyogenic spondylitis.
• The nanoparticle system enhances antibiotic delivery and bacterial targeting, leading to improved treatment efficacy.
• This novel approach offers a potential advancement in managing bacterial bone infections.