Smart hybrid nanomaterials for biomimetic membranes
This thesis focuses on the preparation of nanomaterials made of proteins and polymers. Even though the technology has advanced in the last decades to design new devices at the atomic scale, researchers are still inspired by what Nature has produced and optimized for millions of years. Following this...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | CBUC, CESCA |
| Repositorio: | TDR. Tesis Doctorales en Red |
| OAI Identifier: | oai:www.tdx.cat:10803/668016 |
| Acceso en línea: | http://hdl.handle.net/10803/668016 https://dx.doi.org/10.5821/dissertation-2117-173360 |
| Access Level: | acceso abierto |
| Palabra clave: | Àrees temàtiques de la UPC::Enginyeria química 66 |
| Sumario: | This thesis focuses on the preparation of nanomaterials made of proteins and polymers. Even though the technology has advanced in the last decades to design new devices at the atomic scale, researchers are still inspired by what Nature has produced and optimized for millions of years. Following this concept, this work uses proteins forming water-filled channels, called porins, which regulate the flow of ions and biomolecules in cellular life. Two proteins were studied: Omp2a and VDAC36. The first part of the dissertation is the thermomechanical properties study of the latest hybrid membrane developed by the IMEM group: an thin nanoperforated poly(lactic acid) (PLA) film with the Omp2a porin immobilized onto the surface . For this purpose, a new equipment based on the microcantilever technology was used. The SCAnning LAser analyzer (SCALA) characterizes the coated cantilevers which allows the following of the cantilever bending induced by the compression/expansion of the sample coating (i.e. proteins or polymers). In this study, the intermolecular reorganization of Omp2a aggregates was evidenced as well as the protein secondary structure stability against temperature. The same method was employed to study the impact of nanofeatures (perforations and drugs domains) on films of PLA. They affected the glass transition and the cold crystallization temperatures. The changes were dependent on the size and abundance of the nanofeatures, which can modulate the properties of future materials. Moreover, this work established a protocol for the study of biomolecules and polymers attached to microcantilevers, allowing an accurate study of the thermomechanical properties using very low amounts of sample. The second part of the thesis is the development of new hybrid nanomaterials composed of VDAC36, PLA and poly(3,4-ethylenedioxythiophene) (PEDOT). An efficient protocol was established for the production of VDAC36 and its subsequent refolding was achieved. The beta-barrel nature of the protein was revealed and its tendency to form oligomers was demonstrated. Finally, the size of the protein inner channel could be determined. The VDAC36 was added to the polymer material made of three alternating layers of PLA and PEDOT. The electrical properties of the material were modified by the addition of the protein: the overall resistance was reduced and the supercapacitive behaviour was enhanced. The description of the electrical equivalent circuit also revealed that the protein induced the diffusion of ions. To improve the material, the number of layers was increased and the conducting polymer was modified by incorporating a monomer bearing a dodecyl chain. The modifications were proved useful as the protein content and the electrical properties increased. Finally, the new hybrid material could provide an adaptive electrical response according to the concentration of biomolecules. |
|---|