Preparation Of Injectable Supramolecular Hydrogel Fiber And Its Drug Delivery Property

As a new type of biomedical material,chitosan hydrogel has excellent biocom-patibility and biodegradability,and is an ideal drug delivery carrier.However,its shortcomings are insufficient mechanical strength,very unstable in the human body,and too fast release as a drug carrier.In this study,nanoparticle and hydrogel were combined to prepare injectable nanocomposite hydrogel fiber,which was used as a drug carrier to study the drug release behavior.The addition of nanoparticles not only improves the mechanical properties of the hydrogel,but also solves the problem that the drug-loaded hydrogel is released quickly in the human body.Based on the principle of complexation reaction of carboxymethyl chitosan(CMCh)and zinc ions to generate CMCh/Zn supramolecular hydrogel,this project prepared a CMCh/Zn supramolecular hydrogel fiber using a two-channel four-link injection system.The diameter of the supramolecular hydrogel fibers prepared under different conditions was measured using a microscope,and the swelling properties and degradation properties of the hydrogel fibers were explored.Based on ionic cross-linking method,chitosan nanoparticles were prepared using chitosan and sodium tripolyphosphate,and drug-loaded chitosan carrying ibuprofen and sulfadiazine was prepared using ibuprofen and sulfadiazine as model drug molecules.Nanoparticles were characterized by Fourier transform infrared spectrometer(FT-IR),scanning electron microscope(SEM),and thermogravimetric analyzer(TGA-DSC).Finally,the drug-loaded nanoparticles were mixed with CMCh solution,and then reacted with Zn2+ to prepare nanocomposite hydrogel fibers.The effects of different content of nanoparticles on the mechanical properties of supramolecular hydrogel were investigated using a rotational rheometer.The drug release properties of drug-loaded nanoparticles and drug-loaded nanocomposite hydrogel fibers were studied,and the release results were simulated by pharmacokinetics.The experimental results show that the concentration of CMCh solution and Zn2+solution have an impact on the diameter,swelling performance and degradation performance of supramolecular hydrogel fibers.Testing and characterization of the nanoparticles show that the drug is successfully encapsulated in the nanoparticles.The addition of nanoparticles can improve the mechanical properties of hydrogel fibers;drug release experiments show that dispersing nanoparticles in hydrogel fibers can effectively slow down the drug release time.