Biomedical Engineering Reference
In-Depth Information
- Ti or Ti alloy (TA6V) for the development of the covalent
grafting of a polymer onto a metallic surface and its application in
“total hip prostheses”.
Study on feasibility: grafting onto silicone.
The first grafting of “bioactive polymers” onto the surfaces of
silicone implants was carried out by Hélary
et al.
on toe prostheses by
using a grafting onto technique [YAM 05]. Silicone films were
grafted with bioactive polymers in order to validate the technique of
silicone surface functionalization and to confirm the properties of the
functionalized films [BER 02]; silicone implants were grafted with
“bioactive” polymers then implanted into a rabbit within an animal
infection model [CRE 03]. The
in vivo
results confirmed the obtained
in vitro
results, first on model polymers and then on functionalized
silicone films. The inhibitive properties of the MRSA bacterial
adhesion delivered by bioactive polymers when they are grafted onto a
surface is preserved regardless of the conditions. The experiments on
a rabbit animal model have shown a decrease of the 2 log of the
bacteria adhesion/infection in comparison to the control prosthesis
(silicone). Furthermore,
ex vivo
experiments - implantations of grafted
and non-grafted prostheses followed by its incubation with a bacterial
strain - have helped to confirm the importance of the selectivity of the
layer of proteins adsorbed on bioactive surfaces towards the bacterial
response.
These works on silicone surfaces have allowed us to establish
the feasibility of the covalent grafting of a bioactive polymer on
the surface of an implant and the creation of the expected
biological properties of these surfaces (inhibition of bacterial
adhesion).
The drawback to this grafting technique carried out on silicone
prostheses was that it is not applicable to implantable surfaces made
up of PET, Ti or the alloy TA6V.
In order to overcome this major drawback, we used a radical
grafting technique, which allowed for the grafting of “bioactive”
