Development of biomaterials based on cynaropicrin extracted from Cynara Cardunculus leaves for wound dressing applications

• Autor(a) principal: Lopes, Marta de Jesus Bento
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/162672
• topic: Chitosan Films; Cynara Cardunculus; Cynaropicrin; Pectin Films; Sodium Alginate Films; Wound Dressing; Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias

Developing effective and skin-friendly natural based wound dressings is very important to replace abrasive and non-biological interactive conventional ones. Chitosan, sodium alginate, and pectin are found to be promising biopolymers to prepare biological interactive wound dressings. Phytochemicals such as cynaropicrin (extracted from Cynara Cardunculus leaves) have also shown to be interesting elements for wound dressing applications, due to their anti-inflammatory and antioxidant properties. This thesis focuses on the preparation and characterization of chitosan, sodium alginate, and pectin films doped with ethanolic Cynara Cardunculus leaves extract (CcE). Scanning Electron Microscopy images showed that CcE doping led to less smooth pectin films and more cohesive alginate films, while showing no effect on the physical structure of chitosan ones. Fourier Transform Infrared Spectroscopy spectra showed no impact of the incorporation of CcE on the characteristic chemical bonds of the three biopolymers. Moreover, Thermal Gravimetric Analysis results suggested that CcE doping did not significantly affect the films thermal stability. Swelling degree assays indicated that chitosan films with CcE were less absorbent, and the CcE concentrations used were not enough to improve the physical integrity of both alginate and pectin films in phosphate buffered saline. Contact angle measurements suggested that CcE allowed for tailoring the wettability of alginate and pectin films, even though it did not alter the wettability of the chitosan ones. Additionally, although the CcE doping did not lead to significant modifications in the mechanical properties of all films, chitosan ones appeared to be more resistant while alginate ones showed to be more ductile. Gas permeability tests showed that the produced films behave as a barrier. Finally, pectin-based films presented the highest cynaropicrin release in ethanol. Even though films with CcE must be tailored to suit some requirements of wounds dressings, in view of the importance of extract release, pectin showed to be the most promising biopolymer.