·
Bio-inspired
coating offers a promising antibiotic-free approach to fighting implant
infections and promoting bone integration
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The
research illustrates how nature-inspired surface design and new 3D-printing
technologies may be used together in order to create advanced biomedical
materials.
Mandi: Researchers from the Indian Institute of Technology
Mandi (IIT Mandi) have created a bio-inspired surface coating on 3D printed
bone implants capable of mechanically disrupting bacteria and accelerate integration
of the implant with bones. This research has been published in the Chemical
Engineering Journal, and it employs tiny hydroxyapatite structures resembling
sea urchins on biodegradable plastic scaffolds to tackle two key problems with
orthopedic implants – bacterial infections and poor bone integration.
Large bone defects resulting from traumatic injury,
infections or removal of a tumor still pose great challenges. Although there are
3D-printed implants that use polylactic acid (PLA) which can be tailored to fit
the individual’s bone defect, the hydrophobic nature of PLA does not allow it
to easily bond with bones. Infections because of the adhesion of bacteria and
formation of biofilms may also cause implant failure and subsequent surgery.
Inspired by Nature
The research team—led by Dr. Sumit Murab along
with Ankita Negi, Aakash Verma, K.M. Mohammed Sufiyan and Vedante Mishra
have developed dual-layer coating by using hydroxyapatite which is the
major constituent of human body bone.
The preparation of this layer involves a two-stage
process where the 3D printed PLA scaffold first undergoes activation of surface
by treating it with an alkaline solution that provides the sites of minerals.
In the second stage, the scaffold undergoes hydrothermal treatment at 90°C
leading to the formation of hydroxyapatite needle clusters in the form of a sea
urchin structure.
This creates a surface that utilizes bone-compatible
mineralization together with micro-structures that can cause mechanical damage
to bacteria, unlike the use of antibiotics or antibacterial chemicals.
Towards Safer Orthopedic Implants
When the benefits of customization through 3D printing
and the hydroxyapatite-based biomimicry surface coating technique are
considered together, it appears that this is a promising way to create implants
that allow bone integration and decrease the likelihood of bacterial
colonization.
This relatively easy low-temperature modification
technique may also become one of the possible options for changing properties
of degradable polymer constructs. According to the research team, it could also
become applicable to orthopedic and dental implants, as well as other
biomedical devices in which prevention of infection is crucial.
The research illustrates how nature-inspired surface
design and new 3D-printing technologies may be used together in order to create
advanced biomedical materials.