ObjectiveTo investigate the effects of the classical Chinese medicine compound prescription Erjingwan on the inflammatory response and apoptosis of skeletal muscle cells in a mouse model of sarcopenia and decipher the mechanism based on the silent information regulator 1 （SIRT1）/nuclear factor erythroid 2-related factor 2 （Nrf2）/heme oxygenase-1 （HO-1） signaling pathway. MethodsForty C57/BL6 male mice were randomized into a control group， a model group， and groups with different doses of Erjingwan （8，16，32 g·kg^-1）. The mouse model of sarcopenia was established by D-gal-induced skeletal muscle senescence. The body weight and grip strength of mice treated with different doses of Erjingwan were examined to evaluate their physiological functions. Hematoxylin-eosin （HE） staining and Masson staining were used to observe the pathological changes and fibrosis in the skeletal muscle of mice. Enzyme-linked immunosorbent assay （ELISA） was adopted to determine the levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in the serum samples of mice， and biochemical tests were conducted to quantify the levels of superoxide dismutase （SOD）， malondialdehyde （MDA）， and glutathione （GSH） in the serum. The protein and mRNA levels of SIRT1， Nrf2， B-cell lymphoma （Bcl-2）， and Bcl-2-associated X protein （Bax） were determined by Western blot and Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， respectively. ResultsAfter 4 weeks of drug intervention， the model group exhibited significant reductions in body weight and grip strength （P0.01） compared with the control group. Compared with the model group， all doses of Erjingwan increased the body weight in mice at week 8 （P0.01） and grip strength from week 6 （P0.01）. HE staining revealed clear muscle fiber structure in the control group， muscle fiber rupture and atrophy in the model group， and dose-dependent repair of muscle fiber structure in the Erjingwan groups. Masson staining showed minimal collagen fibers and mild fibrosis in the control group， collagen fiber proliferation and severe fibrosis in the model group， and collagen proliferation with dose-dependent inhibition of fibrosis in the Erjingwan groups. ELISA results showed that serum levels of TNF-α and IL-6 were elevated in the model group compared with those in the control group （P0.01）. After intervention， the low-dose Erjingwan group exhibited a decreased TNF-α level （P0.05）， while the medium and high-dose groups showed decreases in both TNF-α and IL-6 levels （P0.01）. Biochemical assays revealed that the model group had decreased SOD and GSH levels （P0.01） and an increased MDA level （P0.01） compared with the control group. The medium and high-dose Erjingwan groups exhibited increases in SOD and GSH levels （P0.01） and decreases in MDA level （P0.01）， compared with the model group. WB and Real-time PCR results showed that compared with the control group， the model group presented down-regulated protein and mRNA levels of SIRT1， Nrf2， HO-1， and Bcl-2 in the muscle tissue （P0.01） and up-regulated protein and mRNA levels of Bax （P0.01）. Compared with the model group， Erjingwan at different doses up-regulated the protein levels of SIRT1， Nrf2， HO-1， and Bcl-2 （P0.01） and down-regulated the protein and mRNA levels of Bax （P0.01） in the muscle tissue. Low-dose Erjingwan elevated the mRNA levels of Nrf2 and HO-1 （P0.05， P0.01）， and medium and high-dose Erjingwan up-regulated the mRNA levels of SIRT1， Nrf2， HO-1， and Bcl-2 （P0.01）. ConclusionErjingwan reduced the content of inflammatory factors in skeletal muscle cells， improved the antioxidant capacity， and attenuated pathological changes and fibrosis in the muscle of the mouse model of sarcopenia by regulating the SIRT1/Nrf2/HO-1 pathway， inflammatory response， and apoptosis network.

ObjectiveTo investigate the effects of the classical Chinese medicine compound prescription Erjingwan on the inflammatory response and apoptosis of skeletal muscle cells in a mouse model of sarcopenia and decipher the mechanism based on the silent information regulator 1 （SIRT1）/nuclear factor erythroid 2-related factor 2 （Nrf2）/heme oxygenase-1 （HO-1） signaling pathway. MethodsForty C57/BL6 male mice were randomized into a control group， a model group， and groups with different doses of Erjingwan （8，16，32 g·kg^-1）. The mouse model of sarcopenia was established by D-gal-induced skeletal muscle senescence. The body weight and grip strength of mice treated with different doses of Erjingwan were examined to evaluate their physiological functions. Hematoxylin-eosin （HE） staining and Masson staining were used to observe the pathological changes and fibrosis in the skeletal muscle of mice. Enzyme-linked immunosorbent assay （ELISA） was adopted to determine the levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in the serum samples of mice， and biochemical tests were conducted to quantify the levels of superoxide dismutase （SOD）， malondialdehyde （MDA）， and glutathione （GSH） in the serum. The protein and mRNA levels of SIRT1， Nrf2， B-cell lymphoma （Bcl-2）， and Bcl-2-associated X protein （Bax） were determined by Western blot and Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， respectively. ResultsAfter 4 weeks of drug intervention， the model group exhibited significant reductions in body weight and grip strength （P0.01） compared with the control group. Compared with the model group， all doses of Erjingwan increased the body weight in mice at week 8 （P0.01） and grip strength from week 6 （P0.01）. HE staining revealed clear muscle fiber structure in the control group， muscle fiber rupture and atrophy in the model group， and dose-dependent repair of muscle fiber structure in the Erjingwan groups. Masson staining showed minimal collagen fibers and mild fibrosis in the control group， collagen fiber proliferation and severe fibrosis in the model group， and collagen proliferation with dose-dependent inhibition of fibrosis in the Erjingwan groups. ELISA results showed that serum levels of TNF-α and IL-6 were elevated in the model group compared with those in the control group （P0.01）. After intervention， the low-dose Erjingwan group exhibited a decreased TNF-α level （P0.05）， while the medium and high-dose groups showed decreases in both TNF-α and IL-6 levels （P0.01）. Biochemical assays revealed that the model group had decreased SOD and GSH levels （P0.01） and an increased MDA level （P0.01） compared with the control group. The medium and high-dose Erjingwan groups exhibited increases in SOD and GSH levels （P0.01） and decreases in MDA level （P0.01）， compared with the model group. WB and Real-time PCR results showed that compared with the control group， the model group presented down-regulated protein and mRNA levels of SIRT1， Nrf2， HO-1， and Bcl-2 in the muscle tissue （P0.01） and up-regulated protein and mRNA levels of Bax （P0.01）. Compared with the model group， Erjingwan at different doses up-regulated the protein levels of SIRT1， Nrf2， HO-1， and Bcl-2 （P0.01） and down-regulated the protein and mRNA levels of Bax （P0.01） in the muscle tissue. Low-dose Erjingwan elevated the mRNA levels of Nrf2 and HO-1 （P0.05， P0.01）， and medium and high-dose Erjingwan up-regulated the mRNA levels of SIRT1， Nrf2， HO-1， and Bcl-2 （P0.01）. ConclusionErjingwan reduced the content of inflammatory factors in skeletal muscle cells， improved the antioxidant capacity， and attenuated pathological changes and fibrosis in the muscle of the mouse model of sarcopenia by regulating the SIRT1/Nrf2/HO-1 pathway， inflammatory response， and apoptosis network.

Objective: To investigate the awareness of knowledge about hepatitis C prevention and control among outpatients in Ningbo City, Zhejiang Province, and its influencing factors, so as to provide the evidence for strengthening health education on hepatitis C prevention and control. Methods: Based on sentinel surveillance of hepatitis C, the outpatients aged 15 to 65 years at seven hospitals in Yinzhou District, Cixi City and Xiangshan County of Ningbo City were selected using the convenient sampling method from April to June during 2020 and 2022. Demographic information, knowledge and behaviors related to hepatitis C prevention and control were collected through questionnaire surveys. The influencing factors for knowledge about hepatitis C prevention and control were analyzed using a multivariable logistic regression model. Results: A total of 2 792 participants were surveyed, including 1 157 males (41.44%) and 1 635 females (58.56%). The awareness rate of knowledge about hepatitis C prevention and control was 56.23%, and was lower in knowledge about hepatitis C vaccine and treatment. The awareness rates of knowledge about hepatitis C prevention and control among outpatients from 2020 to 2022 were 47.11%, 53.22% and 70.65%, respectively, showing an upward trend (P<0.05). Multivariable logistic regression analysis showed that participants aged 25 to <50 years (OR=1.358, 95%CI: 1.073-1.719), with an educational level of high school or junior college (OR=1.431, 95%CI: 1.134-1.806) or above junior college (OR=3.728, 95%CI: 2.958-4.699), with household monthly income per capita of 3 000 to <5 000 yuan (OR=1.828, 95%CI: 1.344-2.486) or ≥5 000 yuan (OR=1.858, 95%CI: 1.366-2.526), without a history of invasive treatments such as pedicure in public places (OR=1.287, 95%CI: 1.024-1.618), without a history of contact with family members' blood-contaminated items (OR=2.050, 95%CI: 1.552-2.707), and always using condoms during sexual contacts (OR=1.740, 95%CI: 1.273-2.378) had higher awareness of knowledge about hepatitis C prevention and control. Conclusions The awareness of knowledge about hepatitis C vaccine and treatment among outpatients in Ningbo City needs to be improved. Age, educational level, household monthly income per capita, history of invasive treatments such as pedicure in public places, history of contact with family members' blood-contaminated items and frequency of condom use during sexual contacts are associated with outpatients' awareness of knowledge about hepatitis C prevention and control.

Alzheimer’s disease (AD) is a central neurodegenerative disease characterized by progressive cognitive decline and memory impairment in clinical. Currently, there are no effective treatments for AD. In recent years, a variety of therapeutic approaches from different perspectives have been explored to treat AD. Although the drug therapies targeted at the clearance of amyloid β-protein (Aβ) had made a breakthrough in clinical trials, there were associated with adverse events. Neuroinflammation plays a crucial role in the onset and progression of AD. Continuous neuroinflammatory was considered to be the third major pathological feature of AD, which could promote the formation of extracellular amyloid plaques and intracellular neurofibrillary tangles. At the same time, these toxic substances could accelerate the development of neuroinflammation, form a vicious cycle, and exacerbate disease progression. Reducing neuroinflammation could break the feedback loop pattern between neuroinflammation, Aβ plaque deposition and Tau tangles, which might be an effective therapeutic strategy for treating AD. Traditional Chinese herbs such as Polygonum multiflorum and Curcuma were utilized in the treatment of AD due to their ability to mitigate neuroinflammation. Non-steroidal anti-inflammatory drugs such as ibuprofen and indomethacin had been shown to reduce the level of inflammasomes in the body, and taking these drugs was associated with a low incidence of AD. Biosynthetic nanomaterials loaded with oxytocin were demonstrated to have the capability to anti-inflammatory and penetrate the blood-brain barrier effectively, and they played an anti-inflammatory role via sustained-releasing oxytocin in the brain. Transplantation of mesenchymal stem cells could reduce neuroinflammation and inhibit the activation of microglia. The secretion of mesenchymal stem cells could not only improve neuroinflammation, but also exert a multi-target comprehensive therapeutic effect, making it potentially more suitable for the treatment of AD. Enhancing the level of TREM2 in microglial cells using gene editing technologies, or application of TREM2 antibodies such as Ab-T1, hT2AB could improve microglial cell function and reduce the level of neuroinflammation, which might be a potential treatment for AD. Probiotic therapy, fecal flora transplantation, antibiotic therapy, and dietary intervention could reshape the composition of the gut microbiota and alleviate neuroinflammation through the gut-brain axis. However, the drugs of sodium oligomannose remain controversial. Both exercise intervention and electromagnetic intervention had the potential to attenuate neuroinflammation, thereby delaying AD process. This article focuses on the role of drug therapy, gene therapy, stem cell therapy, gut microbiota therapy, exercise intervention, and brain stimulation in improving neuroinflammation in recent years, aiming to provide a novel insight for the treatment of AD by intervening neuroinflammation in the future.

The classic formula Mulisan is the 45th of the 93 formulas in the Catalogue of Ancient Classic Formulas （second batch） of Han medicine published by the National Administration of Traditional Chinese Medicine. It consists of Ostreae Concha， Astragali Radix， Ephedrae Radix et Rhizoma， and wheat， with the effect of replenishing qi and stopping sweating. It is a common formula in the clinical treatment with traditional Chinese medicine. This study analyzes the historical evolution， composition， dosage， original plants and their processing methods， decocting method， efficacy， indications， and modern clinical application of Mulisan by tracing， comparative analysis， and bibliometric methods. The results showed that Mulisan firstly appeared in the Pulse Classic written by WANG Shuhe in the Western Jin Dynasty. The formulation idea can be traced back to the Important Prescriptions Worth a Thousand Gold for Emergency in the Tang Dynasty. The herb composition， dosage， efficacy， and indications of Mulisan were first recorded in the Treatise on Diseases， Patterns， and formulas Related to Unification of the Three Etiologies in the Southern Song dynasty. In terms of original plants and their processing methods， Ostreae Concha is the shell of Ostrea rivularis， which should be calcined before use. Astragali Radix and Ephedrae Radix et Rhizoma are the dried roots of Astragalus membranaceus var. mongholicus and Ephedra sinica， respectively， the raw material of which should be used. Wheat is the dried mature fruit of T. aestivum， which can be used without processing， while the stir-fried fruit， being thin and deflated， demonstrates better effect. The composition of Mulisan is Ostreae Concha 8.26 g， Astragali Radix 8.26 g， Ephedrae Radix et Rhizoma 8.26 g， and wheat 7.92 g. The medicinal materials should be ground into coarse powder and decocted with 450 mL water to reach a volume of 240 mL， and the decoction should be taken warm. In modern clinical practice， Mulisan has a wide range of indications， including spontaneous sweating and night sweating caused by Yang deficiency or Qi deficiency. The clinical disease spectrum treated by Mulisan involves endocrine system diseases， neurological diseases， respiratory system diseases， and cancer. This formula plays a significant role in the treatment of internal medicine diseases in traditional Chinese medicine. This study aims to provide a scientific basis for the subsequent research， development， and clinical application of Mulisan.

The classic formula Mulisan is the 45th of the 93 formulas in the Catalogue of Ancient Classic Formulas （second batch） of Han medicine published by the National Administration of Traditional Chinese Medicine. It consists of Ostreae Concha， Astragali Radix， Ephedrae Radix et Rhizoma， and wheat， with the effect of replenishing qi and stopping sweating. It is a common formula in the clinical treatment with traditional Chinese medicine. This study analyzes the historical evolution， composition， dosage， original plants and their processing methods， decocting method， efficacy， indications， and modern clinical application of Mulisan by tracing， comparative analysis， and bibliometric methods. The results showed that Mulisan firstly appeared in the Pulse Classic written by WANG Shuhe in the Western Jin Dynasty. The formulation idea can be traced back to the Important Prescriptions Worth a Thousand Gold for Emergency in the Tang Dynasty. The herb composition， dosage， efficacy， and indications of Mulisan were first recorded in the Treatise on Diseases， Patterns， and formulas Related to Unification of the Three Etiologies in the Southern Song dynasty. In terms of original plants and their processing methods， Ostreae Concha is the shell of Ostrea rivularis， which should be calcined before use. Astragali Radix and Ephedrae Radix et Rhizoma are the dried roots of Astragalus membranaceus var. mongholicus and Ephedra sinica， respectively， the raw material of which should be used. Wheat is the dried mature fruit of T. aestivum， which can be used without processing， while the stir-fried fruit， being thin and deflated， demonstrates better effect. The composition of Mulisan is Ostreae Concha 8.26 g， Astragali Radix 8.26 g， Ephedrae Radix et Rhizoma 8.26 g， and wheat 7.92 g. The medicinal materials should be ground into coarse powder and decocted with 450 mL water to reach a volume of 240 mL， and the decoction should be taken warm. In modern clinical practice， Mulisan has a wide range of indications， including spontaneous sweating and night sweating caused by Yang deficiency or Qi deficiency. The clinical disease spectrum treated by Mulisan involves endocrine system diseases， neurological diseases， respiratory system diseases， and cancer. This formula plays a significant role in the treatment of internal medicine diseases in traditional Chinese medicine. This study aims to provide a scientific basis for the subsequent research， development， and clinical application of Mulisan.

OBJECTIVE To explore the practice and application effect of lean Six Sigma （LSS） management in the cost- benefit management of PIVAS operation in a tertiary comprehensive hospital （hereinafter referred to as “S Hospital”）， providing reference for the operation and management of PIVAS in hospitals. METHODS The five steps （define， measure， analyze， improve and control， i.e. DMAIC） of LSS management were implemented for PIVAS operation cost-benefit of S Hospital， and lean management was implemented for its cost-benefit management elements （human resource cost， medical and health material cost， and all-in-one parenteral nutrition preparation income）. Several intervention measures including personnel training and performance assessment， refined management system of consumables， and doctor’s advice package of full parenteral nutrition were developed. Finally， the overall improvement effect was evaluated by the total benefit， total cost and net benefit of PIVAS. The effects of human resource allocation optimization and improvement were evaluated by the work efficiency， work quality， job satisfaction， turnover rate and accumulated rest days. The effects of consumables cost management were evaluated by the amount of medical and health materials cost. The improvement effects of all-in-one parenteral nutrition preparation income were evaluated by the profit amount， quantity and the proportion of single bottle of parenteral nutrition. RESULTS After implementing DMAIC in S Hospital， the total benefit of PIVAS was increased from （471 366.50±9 201.5） yuan/month to （479 679.50±14 320.14） yuan/month （P＞ 0.05）， the total cost was decreased from （305 878.88±3 201.75） yuan/month to （294 610.59±5 007.33） yuan/month （P＜0.05）， and the net benefit of PIVAS was increased by 11.83% compared with that before the improvement. The work efficiency， work quality and job satisfaction of employees were significantly improved， the accumulated rest days were significantly reduced， and the turnover rate of third-party employees was reduced from 15.0% before the improvement to 7.5% after the improvement. The cost of medical and health materials significantly decreased from （67 826.42±2 812.76） yuan/month before improvement to （56 384.33±4 607.67） yuan/month after improvement （P＜0.05）. The quantity of all-in-one parenteral nutrition was significantly increased from （1 263.75±135.83） group/month before improvement to （2 061.25±89.04） group/month after improvement （P＜0.05）， and the proportion of users of single bottle of parenteral nutrition in total users decreased from 93.25% before improvement to 58.75% after improvement. The profit of all-in-one parenteral nutrition was 63.18% higher than that before implementing DMAIC. CONCLUSIONS The implementation of PIVAS operation cost-benefit management based on DMAIC is conducive to strengthening the cost control of PIVAS and promoting the healthy development of PIVAS.

Objective:To investigate the effect of laparoscopic splenectomy and azygoportal disconnection (LSD) on liver synthesis and development of liver cirrhosis.Methods:This is a prospective case series study.The clinical data of liver cirrhotic patients with portal hypertension who received LSD at the Department of Hepatobiliary Surgery of Northern Jiangsu People′s Hospital Affiliated to Yangzhou University from September 2014 to January 2016 were included. This study analyzed the diameter of the portal vein, the velocity of portal blood flow, the routine blood parameters, the liver function, the synthetic proteins of liver (antithrombin Ⅲ (AT-Ⅲ), protein S, protein C), and the serum content of liver fibrotic markers(collagen type Ⅳ, procollagen type Ⅲ, laminin, hyaluronidase). Repeated measures ANOVA was used for comparison between multiple groups, and least significance difference was used for post-hoc multiple comparison.Results:A total of 106 patients were included in the study, including 70 males and 36 females, aged (51.8±9.8) years(range: 28 to 75 years).Compared with the preoperative results, the diameter of portal vein and the velocity of portal vein decreased after surgery ( F=14.03, 12.15, respectively, both P<0.01). Compared with the preoperative results, the total bilirubin, albumin, prothrombin time, international normalized ratio, Child-Pugh score and classification were improved ( F=17.96, 56.01, 66.63, 35.83, 33.49, and 27.50, respectively, all P<0.01), and the AT-Ⅲ, protein S, protein C,collagen type Ⅳ, procollagen type Ⅲ, laminin and hyaluronidase levels were also improved ( F=47.87, 36.26, 18.02, 2.79, 14.58, 44.35, and 14.38, respectively, all P<0.01). Compared with the preoperative period, the diameter of portal vein was reduced from the first week to the 24 th month after surgery ( t=5.45 to 9.39, all P<0.01). Compared with the preoperative period, the velocity of portal vein blood from the first week after surgery to the 24 th month after surgery was decreased ( t=4.02 to 8.43, all P<0.01). Compared with the preoperative period, routine blood parameters (white blood count, hemoglobin, platelet count), liver function (total bilirubin, albumin, prothrombin time, international normalized ratio, Child-Pugh score), liver synthetic protein (AT-Ⅲ, protein S, protein C) and liver fibrotic markers (collagen type Ⅳ, procollagen type Ⅲ, laminin, hyaluronidase) were improved to varying degrees at the 24th month after surgery ( t=-20.46 to 11.93, all P<0.01). Conclusion:Preliminary findings show that LSD can reduce portal vein pressure, restore blood cell number, and improve liver synthesis function and the degree of liver fibrosis in patients with portal hypertension in liver cirrhosis.

Objective:To investigate the effect of laparoscopic splenectomy and azygoportal disconnection (LSD) on liver synthesis and development of liver cirrhosis.Methods:This is a prospective case series study.The clinical data of liver cirrhotic patients with portal hypertension who received LSD at the Department of Hepatobiliary Surgery of Northern Jiangsu People′s Hospital Affiliated to Yangzhou University from September 2014 to January 2016 were included. This study analyzed the diameter of the portal vein, the velocity of portal blood flow, the routine blood parameters, the liver function, the synthetic proteins of liver (antithrombin Ⅲ (AT-Ⅲ), protein S, protein C), and the serum content of liver fibrotic markers(collagen type Ⅳ, procollagen type Ⅲ, laminin, hyaluronidase). Repeated measures ANOVA was used for comparison between multiple groups, and least significance difference was used for post-hoc multiple comparison.Results:A total of 106 patients were included in the study, including 70 males and 36 females, aged (51.8±9.8) years(range: 28 to 75 years).Compared with the preoperative results, the diameter of portal vein and the velocity of portal vein decreased after surgery ( F=14.03, 12.15, respectively, both P<0.01). Compared with the preoperative results, the total bilirubin, albumin, prothrombin time, international normalized ratio, Child-Pugh score and classification were improved ( F=17.96, 56.01, 66.63, 35.83, 33.49, and 27.50, respectively, all P<0.01), and the AT-Ⅲ, protein S, protein C,collagen type Ⅳ, procollagen type Ⅲ, laminin and hyaluronidase levels were also improved ( F=47.87, 36.26, 18.02, 2.79, 14.58, 44.35, and 14.38, respectively, all P<0.01). Compared with the preoperative period, the diameter of portal vein was reduced from the first week to the 24 th month after surgery ( t=5.45 to 9.39, all P<0.01). Compared with the preoperative period, the velocity of portal vein blood from the first week after surgery to the 24 th month after surgery was decreased ( t=4.02 to 8.43, all P<0.01). Compared with the preoperative period, routine blood parameters (white blood count, hemoglobin, platelet count), liver function (total bilirubin, albumin, prothrombin time, international normalized ratio, Child-Pugh score), liver synthetic protein (AT-Ⅲ, protein S, protein C) and liver fibrotic markers (collagen type Ⅳ, procollagen type Ⅲ, laminin, hyaluronidase) were improved to varying degrees at the 24th month after surgery ( t=-20.46 to 11.93, all P<0.01). Conclusion:Preliminary findings show that LSD can reduce portal vein pressure, restore blood cell number, and improve liver synthesis function and the degree of liver fibrosis in patients with portal hypertension in liver cirrhosis.

Objective: To establish a method for determining the molecular weight and molecular weight distribution of Poly(Lactide-co-Glycolide Acid) (PLGA) using Size Exclusion Chromatography-Refractive Index-Multiangle Laser Light Scattering (SEC-RI-MALLS) and Size Exclusion Chromatography-Refractive Index (SEC-RID), and to compare the results obtained from these two methods.
Methods: For SEC-RI-MALLS, tetrahydrofuran was used as the mobile phase, Shodex GPC KF-803L was employed as the chromatographic column with a flow rate of 1 mL·min^-1, column temperature at 30 ℃, and an injection volume of 100 μL. For SEC-RID, tetrahydrofuran was also used as the mobile phase, Agilent PLgel 5 μm MIXD-D was used as the chromatographic column with a flow rate of 1 mL·min^-1, column temperature at 30 ℃, differential detector temperature at 35 ℃, and an injection volume of 20 μL. The molecular weight and molecular weight distribution were calculated using Agilent’s GPC software. The newly established methods were validated methodologically, and the molecular weight and molecular weight distribution of 13 batches of samples were determined.
Results: The precision, accuracy, stability, and repeatability tests for SEC-RI-MALLS showed RSD values of 1.35%, 1.58%, 1.53%, and 1.26%, respectively. The SEC-RID method exhibited good linearity (r=0.999 9), with RSD values for precision, accuracy, stability, and repeatability tests (n=6) of 2.05%, 1.62%, 1.30%, and 2.97%, respectively. The results obtained from SEC-RI-MALLS were lower than those from SEC-RID, and the molecular weight distribution coefficient was smaller, but the results from the paired T-test performed with the value measured by SEC-RID method and the value measured by SEC-RI-MALLS method multiplied a conversion coefficient of 1.5 showed no significant difference between the two methods.
Conclusion: Both methods are stable and reliable, and can be used for the determination of PLGA molecular weight and molecular weight distribution based on the specific situations.