doctoralThesis
Obtenção de biomateriais utilizando derivados de taninos e glicosaminoglicanos para aplicações na engenharia tecidual e medicina regenerativa
Fecha
2021-02-02Registro en:
CÂMARA, Paulo César França da. Obtenção de biomateriais utilizando derivados de taninos e
glicosaminoglicanos para aplicações na engenharia tecidual e medicina regenerativa. 2021. 95f. Tese (Doutorado em Química) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2021.
Autor
Câmara, Paulo César França da
Resumen
Developing stable polysaccharide structures with biochemical and biomechanical
properties similar to the extracellular matrix (MEC) is one of the major goals of tissue
engineering and regenerative medicine. Biomaterials used in medical devices need to be
compatible with different biological media, without causing adverse reactions such as
rejection and failure. Increasing the biocompatibility of conventional materials through
surface modification has been shown to be an effective method for improving interaction
with cells and blood components, for example. This work reports a new class of surface
coatings for the purpose of enhancing biocompatibility and cellular response using
multilayer self-assembled polyelectrolytes (PEMs) with a derivative of cationic tannin
(tanfloc) and glycosaminoglycans (chondroitin sulfate or heparin) because they exhibit
similar chemical structures to the ones found in the ECM. The construction of
polyelectrolyte multilayers was monitored by Fourier Transform Surface Plasmon
Resonance (FT-SPR). The surface properties were assessed by X-ray Excited
Photoelectron Spectroscopy (XPS), Atomic Force Spectroscopy (AFM) and contact angle
measurements. The response of human adipose-derived stem cells (ADSCs) was
evaluated in vitro through cytocompatibility assays, adhesion and proliferation of the cells
using fluorescence microscopy. For the hemocompatibility assays, the adsorption of key
serum proteins, adhesion and platelet activation, as well as whole blood coagulation
assays were monitored by XPS, scanning electron microscopy (SEM) and visible
ultraviolet (UV-vis) spectroscopy. The interactions of ADSCs with these new biomaterial
surfaces demonstrate that these surface coatings exhibit good cytocompatibility and that
they promote cell attachment and proliferation. Blood tests point to the high potential of
developing hemocompatible materials through tannin derivatives. Particularities in the
chemical structure of tanfloc were signaled as crucial in the control of blood protein
adsorption, such as fibrinogen, creating an antiplatelet effect on the material’s surface.
The association between biomaterial components, cells and key bioactive molecules in
biological processes important in the reconstruction of large tissue losses highlights the
great potential of materials. These characteristics are very desirable for biocompatible
coatings for applications such as tissue engineering scaffolds and medical devices.