Porous hydrogel antimicrobial nanocomposites

Project Leader: Andrea O'Connor
Staff: Daniel Heath
Student: Dhee Biswas, Tao Huang
Collaborators: Neil O'Brien-Simpson, Phong Tran (QUT), Carolina Tallon (Virginia Tech), Wayne Morrison (O'Brien Institute)
Primary Contact: Andrea O'Connor (a.oconnor@unimelb.edu.au)
Keywords: antimicrobial; biomaterials; hydrogel; nanotechnology; tissue engineering
Disciplines: Biomedical Engineering,Chemical & Biomolecular Engineering
Domains: Convergence of engineering and IT with the life sciences
Research Centre: Particulate Fluids Processing Centre (PFPC)

Antimicrobial resistance is a growing challenge in medicine, particularly in wound healing and use of implanted medical devices. Non-drug antimicrobial nanoparticles are being investigated to address this challenge, as potential therapeutics, device coatings and nanocomposite biomaterial components. Antimicrobial nanoparticles of both silver and selenium have been investigated for their toxicity against a range of bacteria and mammalian cells. The specificity of these nanoparticles against Staphylococcus aureus, its drug resistant form, MRSA (Methicillin resistant Staphylococcus aureus), and Escherichia coli were investigated and selenium doped hydrogels have shown particular promise. The mechanisms of killing the bacteria were probed and selenium has been shown to kill bacteria by damaging its cellular membranes and cell walls.

These nanoparticles have been used as device coatings and incorporated into porous hydrogels to form nanocomposites. Macroporous hydrogels are valuable for cell culture and tissue engineering as their physical and chemical properties can be readily controlled across a wide range relevant for soft tissues. Manipulation of pore properties can be achieved via choice of fabrication methods, including 3D bioplotting and cryogelation. Mechanical, swelling and biocompatibility properties of these types of scaffolds show promise as mimics of the native tissue extracellular matrix for tissue engineering applications. Hydrogel nanocomposites combining the benefits of the macroporous hydrogel systems with tailored antimicrobial nanoparticles are being explored and developed for applications including wound healing.