# Gentamicin‐Loaded Carbonate Apatite with Dual Antibacterial and Osteogenic Functions for Combating Surgical Site Infections

## TL;DR

A new bone substitute loaded with gentamicin quickly fights infection and promotes bone healing, potentially improving surgical outcomes.

## Contribution

Gentamicin-loaded carbonate apatite granules offer dual antibacterial and osteogenic functions for surgical site infection control.

## Key findings

- GM-CAp granules rapidly release gentamicin and show strong antibacterial effects against odontogenic bacteria.
- In vivo studies show GM-CAp suppresses S. aureus infection, reduces inflammation, and promotes bone regeneration.
- Early neutrophil dynamics correlate with infection control and bone healing outcomes following GM-CAp implantation.

## Abstract

Surgical site infections remain a critical concern in dental and orthopedic procedures. To combat surgical site infections, gentamicin‐loaded carbonate apatite (GM‐CAp) granules, a novel antibacterial biomimetic bone substitute is developed. GM‐CAp granules rapidly release the loaded gentamicin, leading to swift suppression of bacteria and proactive prevention of infection. In vitro studies validate the bactericidal effects of GM‐CAp granules against a spectrum of odontogenic bacteria. In vivo investigations confirm the effectiveness of GM‐CAp in suppressing Staphylococcus aureus infection, mitigating inflammation, especially neutrophil recruitment, and stimulating bone regeneration. Transcriptomic analysis reveals that early‐stage neutrophil dynamics may influence the inflammatory milieu and subsequent bone healing in the infected bone defect following CAp or GM‐CAp implantation. Overall, GM‐CAp granules represent a potential strategy for combating surgical site infections and increasing the success rate of bone healing in dental and orthopedic surgeries. Additionally, it is proposed that the status of early postoperative neutrophil recruitment may serve as a potential parameter for evaluating the antimicrobial efficacy of biomaterials.

A bone substitute with gentamicin physically precipitated onto the surface of carbonate apatite exhibits prompt drug release, high bactericidal activity, and osteogenic capacity. Efficient antibacterial activity mitigates early postoperative neutrophil accumulation, the status of which may serve as a potential parameter for evaluating the antibacterial efficacy of biomaterials.