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Updated: Feb 18, 2026
Author Spotlight: Studying Bacterial Growth in 3D Hydrogel Matrices
Published on: January 19, 2024
In Vitro Evaluation of Escherichia coli and Staphylococcus aureus Translocation in 3D Printed Material
Ashma Sharma1, Joshua Prince1, A-Andrew D Jones1,2,3,4
1Department of Civil & Environmental Engineering, Pratt School of Engineering, Duke University, Durham, North Carolina, USA.
Abstract:
Vascular graft infection is a rare but life-threatening condition, primarily occurring after 30 days post-surgery. Meta-analysis has shown that antimicrobial coatings on graft materials do not prevent these infections. Moreover, infections still occurs even though studies have shown that there is no bacterial proliferation or bacterial penetration of common vascular graft material. The time frame of infection, meta-analysis, and in situ studies suggest that bacteria present at the suture site are introduced into the surrounding tissue or that systemically circulating bacteria may be surviving, proliferating, diffusing slowly, and evading host immune defense in synthetic vascular grafts. De novo vascular graft materials, such as tissue-engineered vascular graft material and decellularized vasculature may provide an in situ platform for studying survival, proliferation, and diffusion in tissue and tissue-like materials. In this study, we used confocal microscopy to image the penetration depth of bacteria over time as a proxy for the diffusion of Staphylococcus aureus and Escherichia coli into alginate, GelMA, and decellularized porcine vascular tissue. We quantified viable bacteria breakthrough as a function of biomaterial type. We found that the penetration depth over time was similar in all three biomaterials, however E. coli broke through much less from tissue than from engineered materials, while S. aureus had higher breakthrough in the GelMa but otherwise equal rates. These results point to the possibility of interstitial growth control relative to surface coatings as a future target for engineering infection resistance in engineered vascular grafts.
Insights
Vascular graft infections remain a threat despite antimicrobial coatings. New research shows bacterial diffusion into biomaterials, not just surface contamination, is key. Controlling interstitial growth may prevent future infections.
Area of Science:
- Biomaterials Science
- Infectious Diseases
- Vascular Surgery
Background:
- Vascular graft infections are rare but serious complications occurring >30 days post-surgery.
- Antimicrobial coatings and lack of bacterial penetration in synthetic grafts do not prevent infections.
- Infections may arise from suture site contamination or slow-growing systemic bacteria within grafts.
Purpose of the Study:
- To investigate bacterial diffusion and survival within novel vascular graft materials.
- To compare bacterial penetration in alginate, GelMA, and decellularized porcine vascular tissue.
- To identify potential targets for engineering infection resistance in vascular grafts.
Main Methods:
- Confocal microscopy was used to image bacterial penetration depth over time.
- Staphylococcus aureus and Escherichia coli were used as model bacteria.
- Viable bacteria breakthrough was quantified across different biomaterial types.
Main Results:
- Bacterial penetration depth over time was similar across alginate, GelMA, and decellularized tissue.
- Escherichia coli showed significantly less breakthrough from decellularized tissue compared to engineered materials.
- Staphylococcus aureus exhibited higher breakthrough in GelMA, with similar rates in other materials.
Conclusions:
- Bacterial diffusion into the bulk of biomaterials, not just surface interactions, is critical for graft infections.
- Decellularized vascular tissue demonstrates superior resistance to bacterial penetration compared to engineered materials.
- Controlling interstitial bacterial growth, rather than solely surface coatings, is a promising strategy for infection-resistant vascular graft design.
