Ph.D. Dorota Kolbuk Konieczny from our group was the laureate of the call Sonata of National Science Centre.
The development of technology enables you to know the surrounding world- not only at the macro but also atomic scale. It allows you to learn the mechanisms involved in formation of natural materials and develop synthetic-new one. Further, breading knowledge contributes to more effective materials development for specific applications. The result is a rapidly growing field of science- tissue engineering, which utilizes fundamental knowledge in polymers (plastics)- their formation and crystallization, biology and medicine to develop materials necessary for the treatment of human skin, bone defects ect.
On the one hand, new materials for tissue regeneration are being developed; on the other hand, mechanisms of regeneration of these tissues are observed. Observations led to the development of polymeric, three-dimensional scaffolds naturally occurring in mammalian tissues as Extracellular Matrix. ECM needs to be replicated to enable cellular grow and tissue regeneration. Numerous research groups show increasing activity and ingenuity in the formation of such structures. However, these studies often focus on the 3D architecture. It is often forgotten that the impact of these scaffolds depends not only on whether the cells will be able to migrate but also from the surface of the material. Cell adhesion depends on the hydrophilicity and mechanical properties of the substrate.
The aim of the research was to investigate polymers substrate supermolecular structure effect, mainly crystallinity, on the cells' activity and proliferation during in-vitro studies. The specific goal of the project is analysis of the degree of crystallinity in one- and two-component polymers/foils in terms of cellular response, e.g.: mitochondrial activity, cell proliferation and the development of skeletal actin. Determination of the mechanisms deciding about the increase of bioactivity of the material with an addition of gelatin is a supplementary aim. The proposed optimization of the degree of crystallinity proceeded from the previous literature analysis.
Our results clearly indicate that the molecular weight of the polycaprolactone and related properties are essential for the expression of the integrins. Low molecular weight polycaprolactone revealed higher crystallinity, higher chain mobility at the surface, lower polarity and related higher hydrophobicity. On those substrates, adsorption of proteins took place mainly due to van der Waals binding, which determined cellular adhesion and growth. Contrary, high molecular weight polycaprolactone revealed slightly lower crystallinity and wettability. Surface polarity contributed to hydrogen bonding with adsorbed proteins in-vitro. Therefore, primary protein adsorption was higher and more stable than on low molecular weight polycaprolactone. High molecular weight polycaprolactone revealed higher integrins expression and related cellular adhesion. Collagen and myofibroblast markers as ECM indicators were unaffected by molecular weight, but they were influenced by a high degree of crystallinity within a substrate formed from a polymer of the same molecular weight. Substrates exhibiting the highest crystallinity and lowest surface free energy indicated the highest marker of myofibroblast formation.
