An In Situ Forming Hydrogel Based On Photo-Induced Hydrogen Bonding

Over the past decade,in situ formed hydrogels have become a central issue for its various applications,including drug delivery,cell encapsulation,tissue repair,and wound dressings.Traditionally,flowable matrices of these materials can be introduced into target sites such as tissues,organs,cavities or wounds in a minimally invasive manner before gelation,which has more advantages than those with a fixed shape before implantation,such as easy to operate,similar to biology,it is an ideal drug candidate for controlled drug release matrix.Among various chemical and physical crosslinks,hydrogen bonding is particularly attractive.Although they are usually weaker physical interactions,their further synergy may be equal to the strength of the covalent bond.On the other hand,the thermoplasticity of hydrogen bonds allows them to have excellent self-healing and self-healing properties through reversible network reconstruction.Our group previously synthesized a photosensitive monomer N’-(2-nitrobenzyl)-N-acryloylglycinamide(NBNAGA),which contains the "cage" bisamide moiety,which should most probably be used for construction of dual hydrogen bonding.In this paper,different water-soluble monomers were copolymerized with the light-responsive monomer,NBNAGA.Then,UV light induced dual hydrogen bonding,which benefit the in situ hydrogel preparation.Generally,it is divided into the following three aspects:Firstly,three well-soluble monomers,polyethylene glycol methyl ether methacrylate(OEGMA),acrylic acid(AA),and acrylamide(AM)were copolymerized with the light-responsive monomer,NBNAGA,separately,to further increase the water solubility of the resulting polymer.Using HNMR and GPC characterization methods,it is concluded that the copolymers prepared with AM was better distributed in molecular weight.On the other hand,through the detection of the ultraviolet spectrophotometer,the copolymer photolysis was explored,which confirmed that the 2-nitrobenzyl group in the copolymer can be removed,and the "cage" bisamide groups can be released.Thus it is rational for the dual hydrogen bonding induced hydrogel formation.In the second part,P(AM-co-NBNAGA)copolymer solution was successfully synthesized using one of the water-soluble monomers acrylamide(AM)and the designed amount of NBNAGA photosensitive monomer.The solution is a flowable fluid with viscosity and transparency.After irradiated with 365 nm ultraviolet light,a hydrogel was formed due to the "unaged" double hydrogen bond of the released bisamide group.The frequency sweep rheological properties,self-healing properties,temperature-sensitive properties were studied.Hydrogels formed in situ formed by hydrogen bonds show good temperature sensitivity and self-healing properties,and can be used as a drug carrier for synergistic therapy.Therefore,in the third part,the drug loading and release properties of the prepared hydrogel are studied step by step.Through its own sensitivity to temperature,the strength of the hydrogen bond changes with temperature,and the drug DOX·HCL The release efficiency can reach 25%,38%,52% within 320 minutes,which can be well applied in the field of drug delivery.Figure [19] Table [12] Reference [123]...