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Updated: Aug 22, 2026
High-throughput Identification of Bacteria Repellent Polymers for Medical Devices
Published on: November 5, 2016
One-Step Immobilized Phage Depolymerase Coatings for Catheter-Related Bloodstream Infections
Lingkai Dong1, Xingjin Li2, Tao Hu3
1School of Pharmacy, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
Insights
This study developed a novel coating for medical devices using bacteriophage depolymerases to combat Acinetobacter baumannii infections. The depolymerase-coated surfaces effectively reduced bacterial load and biofilm formation, offering a promising strategy against catheter-related bloodstream infections.
Area of Science:
- Biotechnology
- Materials Science
- Infectious Disease Research
Background:
- Catheter-related bloodstream infections (CRBSI) pose significant clinical and economic burdens.
- Emerging trends show Gram-negative bacilli, particularly Acinetobacter baumannii, are increasingly prevalent CRBSI pathogens due to antibiotic resistance and biofilm formation.
- Bacteriophage depolymerases offer a novel antivirulence strategy by degrading bacterial capsular polysaccharides and exopolysaccharides.
Purpose of the Study:
- To develop and evaluate a polydopamine (PDA)-coated catheter surface functionalized with an Acinetobacter baumannii-specific depolymerase (DPO71).
- To assess the antibacterial, antibiofilm, and in vivo efficacy of the DPO71-PDA coating against Acinetobacter baumannii.
- To determine the coating's stability, robustness, and biocompatibility.
Main Methods:
- Immobilization of A. baumannii-specific depolymerase DPO71 onto various substrates using a mussel-inspired polydopamine (PDA) coating technique.
- Evaluation of antibacterial and antibiofilm activity in vitro using human serum, epithelial cell-bacteria co-cultures, and ex vivo blood infection models.
- Assessment of in vivo efficacy in a mouse subcutaneous implantation model and evaluation of coating stability and biocompatibility using epithelial cells and Galleria mellonella larvae.
Main Results:
- The DPO71-PDA coating achieved significant surface coverage and demonstrated potent antibacterial and antibiofilm activities in the presence of human serum.
- The modified surfaces substantially reduced bacterial burden in epithelial cell-bacteria co-culture and ex vivo blood infection models.
- In vivo studies in mice showed a significant reduction in bacterial load with DPO71-coated implants, alongside good coating robustness, stability, and minimal toxicity.
Conclusions:
- A simple PDA coating technique effectively immobilizes bacteriophage depolymerases onto diverse surfaces, creating potent antibacterial and antibiofilm properties.
- Depolymerase-functionalized coatings show significant potential for mitigating Acinetobacter baumannii-associated CRBSI.
- This approach offers a promising strategy to combat antibiotic-resistant Gram-negative bacterial infections on medical devices.
Abstract:
Catheter-related bloodstream infection (CRBSI) is an important clinical problem that causes significant mortality and excess economic cost. Recent epidemiological trends indicate a shift in CRBSI pathogens from Gram-positive to Gram-negative bacilli, among which Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii predominate due to their strong antibiotic resistance and biofilm-forming capabilities. Recently, bacteriophage-encoded depolymerases have emerged as promising antivirulence agents that resensitize bacteria to host immunity by degrading capsular polysaccharides (CPS) and exopolysaccharides (EPS). In this study, we employed a mussel-inspired polydopamine (PDA) coating technique to immobilize an A. baumannii-specific depolymerase, DPO71, onto diverse organic, inorganic, and metal substrates, with a maximum surface coverage of ∼0.2 µg/cm2. In the presence of human serum, DPO71-coated surfaces demonstrated potent antibacterial and antibiofilm activities. The coating significantly reduced bacterial burden in an epithelial cell-bacteria co-culture system and in ex vivo blood infection models. Moreover, DPO71 coatings demonstrated good robustness, stability, and minimal toxicity toward epithelial cells and Galleria mellonella larvae. Importantly, in a mouse subcutaneous implantation model, the DPO71 coating significantly reduced bacterial load in vivo. Overall, modifying catheter surfaces with depolymerases via a simple PDA coating technique demonstrates great potential in mitigating bacteria-associated CRBSI.
