Can bacteria help build bones implants? 'Yes' say scientists at the University of Birmingham.
Lead researcher Lynne Macaskie suggests that Serratia bacteria that manufacture hydroxyapatite (HA) could be used to make stronger, more durable bone implants.
In a study, the researchers showed that the bacterial cells stuck tightly to surfaces like as titanium alloy, polypropylene, porous glass and polyurethane foam by forming a biofilm layer containing biopolymers that acted as a strong adhesive.
The HA coating then builds up over the surface. For practical use, the HA layer must stick tightly, then the material is dried and heated to destroy the bacteria.
With the help of micro-manipulation technique, the researchers measured the force needed to overcome the bioglue adhesion, and showed that dried biofilm stuck 20-times more tightly than fresh biofilm.
When coated with HA the adhesion was several times more again. Slightly roughening the surface made the bioglue much more effective.
Presently, implant materials are made by spraying-on hydroxyapatite. This does not have good mechanical strength and the spraying only reaches visible areas.
The new biocoating method reaches all the hidden surfaces as the bacteria can "swim" into hidden nooks and crannies.
Macaskie insists that bacterial HA has better properties than HA made chemically as the nanocrystals of HA produced by the bacteria are much smaller than HA crystals produced chemically, giving them a high mechanical strength.
"The bacteria are destroyed by heating, leaving just the HA stuck to the surface with their own glue - rather akin to a burnt milk-saucepan," said Macaskie.
"We need to do more work actually to turn the materials into materials we can use in biomedicine and the environment," she added.
The study was presented at Society for General Microbiology's meeting at Heriot-Watt University, Edinburgh.