Regenerative medicine faces the challenge of developing advanced biomaterials that not only support cell growth but also actively participate in tissue regeneration. Conventional
polymeric materials often do not provide sufficient bioactivity, which is why there is a
growing interest in the functionalization of these materials with piezoelectric and also
bioactive additives. The interest in piezoelectric materials arises from the fact that they can
generate an electric charge in response to mechanical stimuli, which promotes cellular
processes important for tissue healing. Despite their potential, the challenge remains how to
achieve optimal mechanical, surface, and biological properties of such materials without
compromising their biocompatibility.
The aim of the master’s thesis was the preparation of innovative piezoelectric biomaterials
based on poly-L-lactide (PLLA) with the addition of ZnO nanoparticles for application in
regenerative medicine. The main objectives included the optimization of structural and
surface properties and the evaluation of the biological performance of the materials.
Structural analysis showed that the addition of ZnO did not improve the crystallinity or the
chain orientation of PLLA to the extent we expected. Although these are key parameters for
the piezoelectric response, the piezoelectricity of the films increased significantly, mainly
due to the contribution of ZnO nanoparticles, which enhanced the overall response through
their inherent piezoelectricity and influence on shear deformation. Surface properties were
successfully optimized. The addition of ZnO and plasma treatment increased hydrophilicity
and surface roughness and enabled greater exposure of the nanoparticles. This improved the adhesion of human cells. At the same time, we achieved cell proliferation after
piezostimulation with ultrasound.
In piezostimulation testing, PLLA/ZnO films showed an antimicrobial effect, which was
most pronounced at higher concentrations of ZnO, but these concentrations were also
cytotoxic. The optimal balance between biocompatibility and antimicrobial activity was
achieved at a concentration of 1 wt% ZnO, where the results for human cell growth and
bacterial inhibition were the most favorable.
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