Hyperbranched Polyglycerol–Coated Titanium Implants Reduce In Vivo Bacterial Burden Without Compromising Osseointegration — ASN Events
  1. Schedule
  2. Concurrent Session: Symposium - Senescence, Rejuvenation, and Bone Ageing
  3. Hyperbranched Polyglycerol–Coated Titanium Implants Reduce In Vivo Bacterial Burden Without Compromising Osseointegration

Hyperbranched Polyglycerol–Coated Titanium Implants Reduce In Vivo Bacterial Burden Without Compromising Osseointegration (#47)

Helen Tsangari 1 , Iman Sahafnejad 1 , Rebecca K Sawyer 1 , Sameer Al-bataineh 2 , Sue Low 2 , Claire Jones 1 , Tony Simula 2 , Paul H Anderson 1
  1. Adelaide University, Adelaide, SA, Australia
  2. TekCyte Ltd Pty, Adelaide, SA, Australia

Bone-anchored implants are widely used in orthopaedic and dental practice, yet infection and impaired integration remain persistent causes of failure, often driven by bacterial adhesion and biofilm formation at the implant–tissue interface. Current antimicrobial coatings can reduce infection risk but may compromise host cell attachment, delay bone healing, or contribute to antimicrobial resistance. This study evaluates a hyperbranched polyglycerol (HPG) coating designed to create a hydrated, sterically repulsive surface that passively resists protein adsorption and bacterial adhesion while preserving osseointegration and a favourable host tissue response.

Using a combined pre-colonisation and in vivo approach, coated titanium implants were compared with uncoated controls. Under controlled pre-colonisation conditions, Staphylococcus aureus (ATCC 25923; 1×10⁹ CFU/mL) adherence to coated surfaces was markedly reduced compared to titanium (p<0.0001), with near-complete suppression of recoverable bacteria. Implants were then inserted to model early in vivo contamination, and bacterial burden was quantified upon retrieval. Mean bacterial burden was lower on coated implants at both Day 3 and Day 14 (one order of magnitude), although this did not reach significance in the two-way ANOVA (coating p=0.127). However, pooled log-transformed analysis demonstrated a significant overall reduction in bacterial burden (Δlog10 = −0.71, 5-fold reduction; p = 0.028), supporting a time-independent anti-fouling effect.

Osseointegration was then assessed in a rat transcortical femoral screw model at 14 and 28 days using mechanical testing and micro-CT analyses. Mechanical fixation increased significantly from Day 14 to Day 28 (p<0.01), with no effect of coating and no time × coating interaction. A significant ~25–30% increase in peri-implant bone volume over time (p<0.0001) was assessed by micro-CT analyses, with no between-group differences. Peri-implant bone volume was positively associated with fixation strength, indicating preserved structure–function relationships.

Thus, the HPG-coating prevents initial bacterial adhesion and reduces in vivo bacterial burden while maintaining normal osseointegration and mechanical fixation. These findings support a non-antibiotic, interface-engineering strategy to mitigate infection risk without compromising implant integration.