Preparation And Preliminary Quality Evaluation Of AMSN

Arginine deiminase(ADI)The anti-cancer mechanism of arginine deiminase(ADI)is unique,but it is not targeted.It has low activity in the body and is easily inactivated.It has strong immunogenicity.Tumor cells grow fast.Arginine is an essential amino acid for cell growth.Normal cells can synthesize arginine themselves.Tumor cells cannot synthesize arginine by themselves.They must provide arginine for growth through the external environment.Arginine has been found in recent years.Deiminase can inhibit various tumor cells by depleting arginine.The self-assembling delivery system has a large drug load and high biocompatibility,and can improve the stability of the drug in vitro and in vivo.In order to improve ADI's in vivo activity and bioavailability,improve ADI's low biocompatibility and poor targeting,and other defects,this study used polyethylene glycol 1000 vitamin E succinate,HA-g-PEG,fullerol,etc.Arginine deiminase multifunctional self-assembled molecular bionic nanocapsules(AMSN),in order to prolong the biological half-life of ADI,increase the time of ADI in vivo,and improve the bioavailability and stability of ADI.At the same time,preliminary study of the physical and chemical parameters of AMSN,in vitro stability,structure-activity related mechanisms and in vivo kinetics.In the first part of the experiment,HA-g-PEG was first synthesized,and the infrared spectrum of HA-g-PEG was scanned.The results showed that HA-g-PEG was observed as a white flocculent solid from the appearance.The infrared spectrum showed that the amide bond Generated,indicating the successful synthesis of HA-g-PEG.Then AMSN was prepared and the physical and chemical characteristics of AMSN were investigated.In this study,AMSN was prepared by molecular self-assembly method.The appearance was brown suspension with uniform texture.By examining the particle size of AMSN with a Malvern laser particle size analyzer,it is about 283.47 nm,PDI is 0.276,Zeta potential is 10.52 mV,and the encapsulation efficiency is about 58% as determined by the Sephadex-Coomassie brilliant blue method.The optimum temperature is 40 ° C and the optimum pH is 6.0.Under the optimum temperature and optimum pH,the activity of ADI in AMSN is about 126% of the initial activity,indicating that AMSN improves the activity of ADI.The second part of the experiment investigated the in vitro stability of AMSN.The comparison results show that the AMSN's pH stability,thermal stability,anti-trypsin hydrolysis stability,plasma stability and storage stability at 4 ° C and stability in plasma are higher than free ADI,these results are the follow-up experimental research of AMSN Provide directionThe third part of the experiment conducted a preliminary investigation on the mechanism of AMSN activity enhancement and stability enhancement.Compared with free ADI,AMSN increases the stability of ADI.Through this part of the experimental analysis,it can be seen that the possible reason for its increased stability is the change of the conjugated system.AMSN encapsulates ADI inside the system,which increases the stability of ADI.After heat treatment,AMSN can also protect ADI from external environmental changes,thereby maintaining enzyme activityThe fourth part of the experiment investigates the in vitro and in vivo kinetics of AMSN.The pharmacokinetics of AMSN was measured,and the results showed that AMSN not only increased the activity of ADI in rats,but also extended the duration of action.It shows that the preparation of ADI into AMSN can indeed improve the bioavailability of the enzyme in rats,and the sustained release effect is obvious.