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- Preparation of biodegradable functionalized polyesters aimed to be used as surgical adhesivesPublication . Cernadas, Maria Teresa; Gonçalves, Filipa A.M.M.; Alves, P.; Miguel, Sónia P.; Cabral, C.S.D.; Correia, I.J.; Ferreira, PaulaThe study and development of new biocompatible materials to be applied as UV-curable adhesives is extremely important to grant the preparation of matrices with suitable mechanical, biological and thermal properties with a fast curing rate. Herein, photocrosslinkable biodegradable copolymers composed of unsaturated polyesters (UP) and lactic acid oligomers functionalized with 2-isocyanatoethyl methacrylate (IEMA) were produced. Henceforth, three different stoichiometric proportions were tested, which, after the addition of a biocompatible photoinitiator (Irgacure® 2959), resulted in flexible, resistant and uniform matrices after 2 minutes and 30 seconds of crosslinking. The synthesized materials were then further characterized in terms of chemical composition and thermal/mechanical behaviour. The gel content, dynamic contact angles, water sorption capacity and hydrolytic degradation were also assessed. The biocompatibility and antibacterial activity of the produced materials was also evaluated. Taking into account all the data obtained, it may be concluded that the new synthesized biodegradable bioadhesives present promising properties to be used as surgical adhesives.
- Photocurable Polymeric Blends for Surgical ApplicationPublication . Cernadas, Teresa; Santos, Marta; Miguel, Sónia P.; Correia, I.J.; Alves, Patrícia; Ferreira, PaulaThe preparation of photocrosslinkable bioadhesives synthesized from oligomers of lactic acid and polycaprolactone (PCL), both functionalized with 2-isocyanoethyl acrylate (AOI), were studied. The obtained modified macromers of LA-AOI (mLA) and PCL-AOI (mCL) were chemically characterized by 1H NMR and used to formulate polymeric blends with different mass proportions, 1:1, 1:2 and 2:1, respectively. Subsequently, the produced blends were crosslinked, considering two UV irradiation times: 30 and 120 s. After their production, the thermal and mechanical properties of bioadhesives were assessed, where upon the rheology, gel content, hydrolytic degradation and dynamic contact angles were determined. Furthermore, the cytotoxic profile of bioadhesives was evaluated in contact with human dermal fibroblasts cells, whereas their antibacterial effect was studied monitoring Escherichia coli and S. aureus growth. Overall, flexible and resistant films were obtained, presenting promising features to be used as surgical bioadhesives.
- Polyester-based photocrosslinkable bioadhesives for wound closure and tissue regeneration supportPublication . Santos, M.; Cernadas, T.; Martins, P.; P. Miguel, Sónia; Correia, I.J.; Alves, P.; Ferreira, P.Photocrosslinkable surgical adhesives provide many advantages when compared with traditional methods used in wound closure. This work aimed to develop UV-curable biodegradable adhesives based on lactic acid and PCL oligomers. Both materials were functionalized with 2-isocyanatoethyl acrylate (AOI). Subsequently, the photoinitiator (Irgacure® 2959) was added to the blend and then, the final materials were irradiated under UV light for two different times: 30 s and 2 min. After production of adhesives, its physicochemical properties were evaluated through FTIR-ATR and TGA, as well as its rheology, dynamic water contact angle, swelling capacity and hydrolytic degradation. Furthermore, the biocompatibility of the produced adhesives was also characterized in contact with human dermal fibroblasts cells. The antimicrobial activity of the materials was assessed by using Staphylococcus aureus and Escherichia coli, as bacterial models.