Construction And Application Of Hydrogel Drug-loading System

Hydrogels are composed of a three-dimensional polymer network encapsulating a large number of water molecules,and the structure is similar to that of natural extracellular matrix.Hydrogels have widely tunable physical and chemical properties and are a research hotspot in the field of drug delivery vehicles.The hydrogel drug-loading system can continuously deliver various drug molecules locally for a long time,which not only helps to improve the utilization and effectiveness of drugs,but also avoids the toxic and side effects of high-dose drug exposure,which is of great significance in the field of therapy.The sustained release kinetics of polymer hydrogel drug carriers is related to the network structure of the hydrogel.The polymer networks constructed by different cross-linking methods are different,resulting in differences in physicochemical properties.According to the needs of different applications,selecting the appropriate cross-linking method and rationally designing the hydrogel drug-loading system can better achieve the drug effect,reflecting the value of the hydrogel drug-loading system in biomedical applications.This dissertation focuses on the rational design of hydrogel drug-carrying systems,constructs hydrogel carriers for drug delivery,and explores their applications.The specific research is as follows:(1)A thermosensitive hydrogel carrier was designed and fabricated for the delivery of honokiol nanocrystals(MAG-NCs)for the treatment of Parkinson’s(PD).The hydrogel carrier was obtained by natural cooling of a mixed temperature-sensitive emulsion of free-radically polymerized poly(N-isopropylacrylamide)(PNIPAM)and methacryloyl gelatin(GelMA).The MAG-NCs-loaded hydrogel(MAG-NCs@Gel)exhibits good shear-thinning and self-healing properties and can be locally injected into the nasal cavity.The hydrogel undergoes a body temperature-induced LCST(32.2°C)phase transition,which exhibits reduced transparency and enhanced viscoelasticity.The MAG-NCs@Gel system uniformly loads MAG-NCs,inhibited nanocrystal agglomeration,and was stable in storage for more than 14 days.And it can adhere to the nasal mucosa and release the drug slowly,and the release rate is close to 100% within 72 h.The released MAG-NCs reach the central nervous system via the trigeminal nerve and olfactory system,and have the effect of treating PD.(2)A growth factor-loaded hydrogel dressing was constructed by utilizing hydrophobic interaction and Schiff base reaction.First,watersoluble chitosan quaternary ammonium salt(QCS)and Pluronic F127(AF127)with aldehyde end groups were prepared.Then,the polymer network of the hydrogel was constructed based on the self-assembled micelles of AF127 in aqueous solution due to hydrophobic interaction and the imine bond generated between QCS and AF127.Platelet-rich plasma(PRP)was added to the hydrogel to obtain a shear-thinning,adherent,and degradable growth factor-loaded hydrogel(QCS/PRP/AF127).The dressing can slowly release growth factors for 5 days to promote the healing of chronic diabetic wounds.