The preva‎lence of periodontal diseases results from intricate interactions between the host immune system and microbial plaque organisms. The analysis of alveolar bone and tooth loss is considered an outcome of these diseases. Hydrogels, due to their facile permeability in the periodontal pocket, represent the optimal choice for improving periodontal diseases. Incorporating drugs such as doxycycline into hydrogels can enhance their effectiveness against periodontal diseases, owing to their antibacterial properties. However, using hydrogels alone for controlling drug release may not be sufficient, and in this regard, molecularly imprinted polymers can be employed. The objective of the present research is to fabricate and characterize injectable hydrogel composites containing varying amounts of molecularly imprinted bioglass microspheres (2%, 5%, and 7% w/w) loaded with doxycycline for the treatment of periodontal diseases. Initially, bioglass microspheres were synthesized using the sol-gel method and modified with chitosan. Molecularly imprinted bioglass microspheres were then prepared using the surface molecular imprinting method, with doxycycline as the template. Gelatin was separately modified with methacrylate groups. Subsequently, after characterizing the particles and the gelatin precursor, the molecularly imprinted bioglass microspheres were added to the gelatin hydrogel matrix, and the resulting composites were characterized. Results indicated that the modification of bioglass microspheres with chitosan and the surface molecular imprinting method led to the creation of new functional groups and a change in particle size from 370 ± 12 nm to 566 ± 30 nm. Surface charge measured changed from -50± 1.87 to -60 ± 1.46 mV. Temperature sensitivity and acidic pH equilibrium adsorption capacity of the molecularly imprinted bioglass microspheres demonstrated the highest equilibrium adsorption capacity at 35 oC (96 ± 2 mg/g) and in pH=9 (122± 2 mg/g). selectivity towards the doxycycline template, antibacterial activity, over 128% viability against osteoblast cells (MG-63) after 3 days of culture, and an increase in calcium deposition over time during the alizarin red test demonstrated the success of the surface molecular imprinting method. Additionally, to eva‎luate the effect of molecularly imprinted bioglass microspheres in the hydrogel composite, gelation time, swelling capacity, degradation rate, mechanical and rheological properties, blood compatibility, and biocompatibility of the hydrogels were investigated. Increasing the particle concentration to 7%w/w resulted in reduced degradation and swelling of the composite hydrogel compared to the pure gelatin hydrogel. Furthermore, composite hydrogels containing 2%w/w and 5%w/w of Molecularly imprinted bioglass microspheres released approximately 50% of the drug in the first 4 days, with sustained release up to 7 days. Adding 2%w/w of molecularly imprinted bioglass microspheres significantly improved mechanical properties, including compressive modulus (41 ± 2 kpa), compressive strength (51 ± 9 kpa), and elasticity (5.6 ± 3.0 Kj/m2). The composite hydrogel containing 5% w/w microspheres exhibited suitable viscoelastic behavior, lower hemolysis rate, and increased calcium deposition compared to the pure gelatin hydrogel, with over 110% viability after 3 days of culture and 45% cell proliferation after 5 days of culture. Moreover, the antibacterial activityeva‎luation of the composite hydrogels showed that increasing the concentration of molecularly imprinted bioglass microspheres led to a significant increase in the halo diameter of growth inhibition. Overall, based on the obtained results, the composite hydrogel containing 5% w/w of molecularly imprinted bioglass microspheres can be considered an optimal sample with the potential for the treatment of periodontal diseases.

مهشيد خرازيهاي اصفهاني

محمد ديناري , سعيد نوري خراساني