790: Influence of 2-Thiobarbituric Acid on the Structural and Rheological Properties of Injectable Hydrogels

Ö. Zeynep Güner-Yılmaz^a*, Öykü Naz Duranlar^a, Simge Çetin^a F. Seniha Güner^a

^aIstanbul Technical University, Department of Chemical Engineering, Istanbul

^*yilmaz.zeynep@itu.edu.tr

Injectable hydrogels are widely explored in biomedical applications due to their biocompatibility, tunable rheological properties, and ability to mimic the extracellular matrix. In this study, the effect of 2-thiobarbituric acid (TBA) incorporation on the structural and rheological properties of alginate/PVP-based injectable hydrogels was investigated. TBA has been previously reported to enhance mechanical properties and promote cell proliferation in film-type wound dressings[1,2].

Hydrogels were prepared using two alginate concentrations(4% and 6%) and crosslinked with calcium ions at varying concentrations(0.5%, 0.6%, 0.7%). The resulting formulations were characterized in terms of morphology, chemical composition, and mechanical behavior. Scanning Electron Microscopy(SEM) and Energy-Dispersive X-ray Spectroscopy(EDS) were used to visualize surface microstructure and confirm TBA incorporation, while FTIR spectroscopy revealed partial integration of TBA into the polymer matrix. Rheological assessments were performed through creep-recovery tests and shear rate–shear stress measurements to investigate structural stability under deformation and flow behavior relevant to injectability. Lap shear testing was conducted to evaluate interfacial adhesion, and visual self-healing experiments provided further insights into internal cohesion and recovery ability.

The results showed that TBA-containing hydrogels exhibited more dynamic recovery following mechanical stress, higher viscosity at low shear rates, and shear-thinning behavior favorable for injection. SEM and EDS analyses confirmed a more porous structure and sulfur content in TBA-containing samples, respectively. Although TBA incorporation slightly reduced lap shear adhesion, it significantly enhanced internal self-healing and mechanical resilience under cyclic loading. These findings suggest that TBA contributes to internal cohesion and dynamic recovery capacity in hydrogel systems designed for intracorporeal use.

[1] Guner OZ, Kocaagaa B, Batirel S, Kurkcuoglu O, Guner FS. 2-Thiobarbituric Acid Addition Improves Structural Integrity and Controlled Drug Delivery of Biocompatible Pectin Hydrogels (2021) International Journal of Polymeric Materials and Polymeric Biomaterials, 70(10), 703-711. https://doi.org/10.1080/00914037.2020.1760272 

[2] Kocaaga B, Öztürk Y, Kurçin HC, Güner Yılmaz ÖZ, Kurkcuoglu O, Tatlier M, Özdemir İ, Kervancioglu Demirci E, Kotil T, Solakoğlu S, Aksu B, Batirel S, Bal-Öztürk A, Güner FS. Developing multifunctional pectin-based hydrogel for wound dressing: In silico, in vitro and in vivo evaluation. (2024) European Polymer Journal, 216, 113280. https://doi.org/10.1016/j.eurpolymj.2024.113280