Study On Drug Loading Structure And Drug Release Behavior Of 4D Printed Shape Memory Polymer

Shape memory polymer is a kind of intelligent material,which can respond to external stimuli,resulting in complex shape and function changes.Polylactic acid is a kind of shape memory polymer due to its excellent degradability and biocompatibility,it is widely used in the field of biomedicine.3D printing technology based on smart materials is widely known as 4D printing technology,which combines the advantages of smart materials with additive manufacturing.Traditional drug processing techniques often have problems such as limited drug loading,low drug encapsulation efficiency,inaccurate drug loading,and possible chemical reactions between drugs and drug excipients.The emergence of 4D printing technology has broken through the limitations of traditional drug processing technology,it can increase the drug loading,and the drug encapsulation rate is high,while ensuring the accuracy of drug loading.The drug-loading structure prepared by 4D printing can also control the drug release amount through its own intelligent deformation,and realize the intelligent release of the drug.This study is aimed at the application of 4D printed shape memory polymers in the biomedical field.Three ciprofloxacin hydrochloride drug-loading structures were prepared by 4D printing shape memory polymer.Based on this,a paclitaxel-loaded breast stent was designed.The shape memory behavior and drug release behavior of the drug-loaded structure and the drug-loaded breast stent were studied,and a magnetically deformable breast stent was prepared.Firstly,starting from the raw materials,study on the in vitro cytotoxicity of the shape memory polylactic acid granules and the polylactic acid 4D printing filaments and polyethylene glycol/polylactic acid 4D printing filaments prepared based on it.Second,on this basis,the preparation,ciprofloxacin hydrochloride/polylactic acid 4D printing filaments,ciprofloxacin hydrochloride/polyethylene glycol/polylactic acid 4D printing filaments,paclitaxel/polylactic acid 4D printing filaments,paclitaxel/polyethylene glycol/polylactic acid 4D printing filaments,Fe3O4/polylactic acid 4D printing filaments were prepared.Through the differential scanning amount analysis and thermogravimetric analysis,the thermal performance of the drug-loaded 4D printing filaments was studied and analyzed,and the performance difference between the pure material 4D printing filaments and the drug-loaded 4D printing filaments was compared.By Fourier infrared spectroscopy,determining that the material is physically mixed with the drug,the preparation method of the drug-loaded 4D printing filaments does not destroy the chemical structure of the drug.Then,the petal,spiral and column drug-loading structures and drug-loaded breast stents were designed by digital modeling.The drug-loaded 4D printing filaments was printed by a fused deposition printer to prepare three drug-loading structures loaded with ciprofloxacin hydrochloride and a drug-loaded breast stent loaded with paclitaxel.Finally,the shape memory properties and drug release behavior of drug-loaded structures and drug-loaded breast stents were studied.The effects of shape,deformation,and material on drug-loading structure and drug release behavior of drug-loaded breast stent were analyzed.The in vitro deployment of the magnetically driven breast stent was realized,and the feasibility of implementing the magnetic drive remote control by the minimally invasive surgery implanted the breast stent was verified.In this paper,the in vitro cytotoxicity experiments of the materials confirmed that the polylactic acid particles,polylactic acid 4D printing filaments and polyethylene glycol/polylactic acid 4D printing filaments are non-cytotoxic and can be applied in the field of biomedicine.The performance of the drug-loaded 4D printing filaments prepared on this basis was characterized,the deformation parameters of the drug-loading structure and the drug-loaded breast stent were determined,and their shape recovery behavior was studied.It was verified that the addition of ciprofloxacin hydrochloride and paclitaxel did not affect the shape memory properties of polylactic acid.It is determined that the drug release rate of 4D printed shape memory polymer drug-loading structure and stent with its surface area to volume ratio are positively correlated.Furthermore,the in vitro recovery of the magnetically driven breast stent was verified,and the rationality and feasibility of the drug-loading structure and breast stent prepared based on 4D printed shape memory polymer were verified.Provide theoretical basis for 4D printed shape memory polymer to achieve new pharmaceutical dosage forms and personalized custom stents.