Research On Preparation And Performance Of Intelligent Biopolysaccharide Hydrogels

As a kind of new composite material,magnetic response self-healing hydrogels utilizes the characteristic of magnetic drug-loaded microspheres and self-healing hydrogels at the same time.Traditional hydrogels usually do not have the function of self-healing.After the external damage,large cracks and damages would occur on the surface of the hydrogels,which are often irreversible to their structures.However,the preparation of the new intelligent self-healing hydrogels is expected to break through the bottleneck and ensure the hydrogels could spontaneously repair and self-heal the external damage after being transported to the human body.Therefore,the integrity of the structure and stability of the hydrogels could be ensured.Nano-sized magnetic microspheres have different physical and chemical properties from their conventional size properties,which make them widely used in mri,hyperthermia drug delivery and other fields.Under the action of external magnetic field,magnetic microspheres could reach the target position and maintain a high concentration within a certain period of time,without toxic effects to other normal tissues.As a new type of drug carrier,intelligent magnetic nano-scaffold materials is expected to be widely used in the field of medicine to achieve the effect of slow release of drugs in specific areas.The aim of this paper is to prepare a dynamical injectable composite hydrogels encapsulated with magnetic microspheres for drug delivery and anti-cancer therapy.The hydrogels was formulated by mixing water-soluble carboxyethyl(CEC)and oxidized alginate(OAlg)via Schiff-base reaction and possesses the excellent self-healing property.To strengthen the mechanical and biodegradable capabilities of hydrogels,5-fluorouracil(5-Fu)loaded magnetic gelatin microspheres(MGMs)were prepared by an emulsion cross-linking method and embedded into the composite hydrogels.To identify the differences of concentrations of MGMs integrated into the hydrogels,many properties such as the magnetic properties,swelling,degradation,rheological behaviors and drug release in vitro were tested.Considering all these factors,we found that the 30mg/mL MGMs/Gel were provided with the best performance and showed excellent self-healing ability under physiological conditions via the dynamic Schiff-base re-linkage.In in vitro drug release,the composite hydrogels with the MGMs showed the best sustained release of 5-Fu compared with single MGMs and Gel.Therefore,the CEC/OAlg-based dynamical hydrogels encapsulated 5-Fu/MGMs are expected to be a promising platform for drug delivery and various biomedical fields.