Functionalization of graphenic surfaces by oxygen plasma toward enhanced wettability and cell adhesion : experiments corroborated by molecular modelling

Graphenic materials attract huge attention because of their outstanding properties, and have a wide range of applications as, i.e., components of biomaterials. Due to their hydrophobic nature, however, the surfaces need to be functionalized to improve wettability and biocompatibility. In this study, we investigate the functionalization of graphenic surfaces by oxygen plasma treatment, introducing surface functional groups in a controlled way. The AFM images and LDI-MS results clearly show that the graphenic surface exposed to plasma is decorated with -OH groups, whereas the surface topography remains intact. The measured water contact angle decreases significantly after oxygen plasma treatment from $99^{\circ}$ to ca. $5^{\circ}$, making the surface hydrophilic. It is also reflected in the surface free energy values which increase from 48.18 mJ $m^{−2}$ to 74.53 mJ $m^{−2}$ when the number of surface oxygen groups reaches 4 -OH/84 $Å^{2}$. The DFT (VASP) molecular models of unmodified and oxygen-functionalized graphenic surfaces were constructed and used for molecular interpretation of water-graphenic surface interactions. The computational models were validated by comparison of the theoretically determined water contact angle (based on the Young–Dupré equation) to the experimentally determined values. Additionally, the VASPsol (implicit water environment) results were calibrated against the explicit water models that can be used in further research. Finally, the biological role of functional groups on the graphenic surface was examined in terms of cell adhesion with the use of mouse fibroblast cell line (NIH/3T3). The obtained results illustrate the correlation between surface oxygen groups, wettability, and biocompatibility providing the guidelines for the molecular level-driven design of carbon materials for various applications

Development of software designed to aid in automatic optimization of force field parameters based on sorption experiment data

Praca skupia się na opracowaniu narzędzia służącego do automatyzacji procesu uzbieżniania parametrów pól siłowych w symulacjach komputerowych z dziedziny chemii obliczeniowej. Opisywany jest proces projektowania oprogramowania, identyfikowane są jego elementy, oraz omawiane są wykorzystywane technologie i narzędzia. Powstała wersja kodu jest następnie poddawana serii testów oceniających jej przydatność w docelowym zastosowaniu. Całość kończy omówienie wyników testów i próbna optymalizacja parametrów pola siłowego TraPPE w symulacji procesu adsorpcji propanu na zeolicie CHA.Thesis focuses on developing a tool to automate fitting force field parameters in computer simulations. It describes the process of designing, goes in detail about utilized technologies. Developed code is then tested in a series of tests ti evaluate its use in real world application. Finally optimization of force field parameters is carried out

Polylactide Nanotructures in water solution and their interactions with chosen drugs

Praca licencjacka dotyczy roli polilaktydu (PLA) w różnych dziedzinach życia codziennegow szczególności skupia się na wykorzystaniu tego polimeru w zastosowaniach biomedycznych. Najbardziej interesującym zastosowaniem PLA jest wykorzystanie tego polimeru jako nośnik leków do organizmów żywych. Praca obejmuje badania literaturowe nośników leków opartych o PLA. W kolejnej części przedstawiono wyniki przeprowadzonych symulacji komputerowych metodą dynamiki molekularnej układu PLA-woda w celu obrazowania PLA w środowisku wodnym. Przeprowadzone symulacje pozwoliły określić szereg parametrów charakteryzujących kłębek polimeru.This paper is about role of polylactide in everyday life, and especially, its usage in biomedical applications. The most interesting application is in new ways of administering and delivering drugs. Work consists of literature research about drug carriers derived from PLA and also molecular dynamic simulation of PLA-water system with result analysis