Development and characterization of a methacrylated pectin based bioink for wound dressing applications

The skin is the largest organ in the human body and performs many essential functions, which can be compromised when the epidermis is damaged, exposing the dermis to air and resulting in a wound. Traditional dressings, although inexpensive and capable of absorbing blood and secretions, have some disadvantages such as adhesion to tissues that causes pain upon removal. In contrast, modern dressings, such as those based on hydrogels, are easy to remove, offer biocompatibility and biodegradability, and can be enriched with active substances or natural extracts with therapeutic properties. This thesis focuses on the development and characterization of a methacrylated pectin (PECMA) based bioink, preliminarily exploring its application for wound treatment. Pectin was methacrylated by the addition of two different amounts of methacrylic anhydride and was subsequently chemically characterized. The hydrogel design was optimized using dual cross-linking, both chemical and ionic, obtained by photopolymerization and the addition of Ca²⁺ ions. Photocrosslinking kinetics was studied by photorheology. Subsequently, mechanical characterization of the material was conducted, shear thinning behavior was evaluated, and extrusion-based 3D bioprinting was carried out. Additionally, studies on the cytocompatibility of the bioink were performed, along with investigations into the degradation kinetics and water uptake of the hydrogel. Finally, preliminary studies were conducted on the incorporation of fumed silica, previously mixed with extracts of rosehip and devil's claw using a ball milling technique, to impart antioxidant activity to the PECMA-based material, which may be advantageous for wound treatment.