Polymeric implant for bone regeneration in order to be useful has to fulfill several conditions: biocompatibility, mechanical properties similar with real bone, suitable rate of degradation subjected to rate of bone reconstruction with harmless degradation byproducts, proper porosity, etc. There is a distinct difficulty in finding only one right material completing these tasks. That is why researches are directed into composite materials with additionally surface modification in order to make it more attractive for cells. A principle condition of growth, proliferation and differentiation of osteoblast is their adherence and suitable interactions with support.
In our preliminary research we were observing growth of osteoblasts on solid support modified with alternating polymeric polyelectrolyte films. One solid polystyrene PS support was coated with poly(acrylic acid) A film, next one with A and bentonite B film, next with A/B/A and continuously next one with A/B/A/B and so on. Each support with top layer from A or B had roughly the same wettability measured by contact angle CA of water or DMEM drops. But the osteoblast cells growing on PS support coated with alternating A and B layers were somehow "recognizing" how thick this polyelectrolyte film is. We suggest, that surface properties - surface elasticity and fluidity play more important role in the cells growth than surface wettability measured by CA values. The influence of mechanical properties on cells growth is widely discussed. In purpose to clarify this point we have decided to make the following experiments:
Deposition of multilayer system prepared from A/B layers.
Surface wettability (CA)
Surface properties with AFM: topography.
Surface properties with AFM: friction mode.
Biological tests - morphological observations, cell proliferation (crystal violet staining), XTT viability assay
Obtained results are discussed.
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