ABSTRACT
In recent years, the biopharmaceutical industry has grown rapidly, and the market size of monoclonal antibody drugs has increased significantly. Accurate structural characterization and quality control are the supporting technologies for the development of monoclonal antibody drugs. As a significant post-translational modification of antibody drugs, glycosylation has an important influence on its efficacy, stability, and immunogenicity. The existing literature usually uses liquid chromatography-mass spectrometry to perform major glycosylation modifications of monoclonal antibody drugs. Characterization, there are few studies on low-abundance glycosylation, but the characterization and control of low-abundance glycosylation cannot be ignored. In this study, we have established a qualitative and quantitative analysis technology for N-glycans based on RapiFluor-MS reagent-labeled monoclonal antibody drugs. This method has a short sample processing time and high sensitivity. It can not only characterize the main glycoforms of three monoclonal antibody drugs (adalimumab, bevacizumab, and trastuzumab) but also can quantify low-abundance N-glycans. The results of the study showed that the main glycoforms specified in the Pharmacopoeia could be detected in different batches of monoclonal antibody drugs, but the content of N-glycans in different batches of samples is not identical. After that, we analyzed the N-glycans connection sites and glycoforms at the intact glycopeptide level, further enriching the N-glycans structure information of the monoclonal antibody. The qualitative and quantitative analysis technology of N-glycans based on RapiFluor-MS reagent-labeled monoclonal antibody drugs can realize the in-depth characterization and control of glycosylation modification of monoclonal antibody drugs.
ABSTRACT
The research and development of monoclonal antibodies (mAbs) is a rapidly developing field. From the first generation of murine mAbs to the fourth generation of fully human mAbs, the efficacy and safety of mAbs in the treatment of various diseases have been continuously improved. In order to regulate the development and evaluation of mAbs, drug regulatory agencies and pharmacopeias of America and China have tried to issue feasible test procedures and acceptance criteria for quality evaluation of mAbs and biosimilars. Mass spectrometry (MS) technique with high sensitivity, resolution, selectivity, and specificity has become an important tool to evaluate the quality characteristics of monoclonal antibody-related products or specify mAb quality. The research of MS-based monoclonal antibody study involves structure characterization, impurity analysis, pharmacokinetics/pharmacodynamics (PK/PD), etc. This review focuses on the current quality control requirements of mAb related products and the development of MS technique for mAb quality characterization and specification. It is expected to provide information and references for evaluating the quality of monoclonal antibodies under research and development.
ABSTRACT
BACKGROUND: Peripheral nerve injury can lead to extensive changes in central nervous system, and exercise training can promote the recovery of locomotor function following central nervous system injury. OBJECTIVE: To observe the changes of locomotor function and the expression levels of vesicular glutamate transporter VGLUT1 in the spinal cord in a rat model of dorsal root ganglion resection after treadmill exercise and to explore the effect of treadmill training on the locomotor function after peripheral nerve injury. METHODS: Thirty-nine 10-week-old male Wistar rats were randomized into experimental (n=15), control (n=15) and sham operation (n=9) groups. The rats in the experimental and control groups received the dorsal root ganglion resection at L3and L4segments to establish the model of peripheral nerve injury under local anesthesia, while the rats in the sham operation group were only subjected to dorsal root ganglion exposure. The rats in the experimental group underwent 15 m/minute treadmill training at postoperative 7 days, while rats in the other two groups were in free movement. Gait analysis was performed at preoperative 3 days, postoperative 7, 14, 21, and 28 days, respectively, and the behavioral changes of rats were observed. The tissue sections were obtained from L3segment at postoperative 7, 14, and 28 days to detect the expression levels of VGLUT1 in the spinal cord by immunohistochemistry. RESULTS AND CONCLUSION: The peroneal nerve function index in the experimental and control groups was lower than that before surgery and that in the sham operation group at postoperative different time points (all P ＜ 0.05). The index in the experimental and control groups was the lowest on day 7 postoperatively (P ＜ 0.05), then the index gradually increased, but was still lower than the preoperative level (P ＜ 0.05). The index in the experimental group was significantly higher than that in the control group at postoperative 21 and 28 days (P ＜ 0.05). The expression levels of VGLUT1 in the lamina IX in the experimental and control groups were significantly lower than those in the sham operation group at different time points after surgery (P ＜ 0.01). The levels in the experimental group were significantly higher than those in the control group at postoperative 14 and 28 days (P ＜ 0.05). The levels in both groups on a decline after surgery, especially the control group (P ＜ 0.05). These results suggest that treadmill can promote the recovery of locomotor function post peripheral nerve injury.