Objective: To replace esophageal defects with artificially composed biodegradable materials and non-biodegradable materials. Met hods: A two-layered tube consisting of a collagen-chitosan sponge and an inner polyurethane stent was used to replace 5 cm esophageal segmental defect s in 15 dogs. The inner polyurethane stent was removed endoscopically at weekly intervals from 2 or 4 weeks. Results: Partial regeneration of es ophageal epithelia was observed in 5 dogs at week 2, and progressing constricti on occurred and the dogs became unable to swallow within 1 month. In the 10 dog s that the polyurethane stent was removed at week 4, regenerated esophageal tiss ue successfully replaced the defects, and complete epithelization was observed 1 month after surgery. Complete regeneration of esophageal mucosa structures, inc luding mucosal smooth muscle and mucosal glands were observed 3 months after surgery, and partial regeneration of esophageal muscle tissue was also observed 6 months after surgery. Conclusion: Our artificial prosthesis i n reconstruction of the cervical esophagus segment in dogs is feasible. Through temporary polyurethane tube, collagen-chitosan sponge provides a three-dimensi onal structure suitable for the regeneration and sufficient degradation time for the complete regeneration of esophagus.

Objective: To replace esophageal defects with artificially composed biodegradable materials and non-biodegradable materials. Met hods: A two-layered tube consisting of a collagen-chitosan sponge and an inner polyurethane stent was used to replace 5 cm esophageal segmental defect s in 15 dogs. The inner polyurethane stent was removed endoscopically at weekly intervals from 2 or 4 weeks. Results: Partial regeneration of es ophageal epithelia was observed in 5 dogs at week 2, and progressing constricti on occurred and the dogs became unable to swallow within 1 month. In the 10 dog s that the polyurethane stent was removed at week 4, regenerated esophageal tiss ue successfully replaced the defects, and complete epithelization was observed 1 month after surgery. Complete regeneration of esophageal mucosa structures, inc luding mucosal smooth muscle and mucosal glands were observed 3 months after surgery, and partial regeneration of esophageal muscle tissue was also observed 6 months after surgery. Conclusion: Our artificial prosthesis i n reconstruction of the cervical esophagus segment in dogs is feasible. Through temporary polyurethane tube, collagen-chitosan sponge provides a three-dimensi onal structure suitable for the regeneration and sufficient degradation time for the complete regeneration of esophagus.

BACKGROUND:The most prominent transcription factor activated by tumor stem cells in osteosarcoma is EZH2,and silencing of EZH2 has been reported to inhibit osteosarcoma cell growth.Studies have confirmed that bovine serum albumin-chitosan nanoparticles are a drug delivery vector with excellent biocompatibility and biodegradability,and the albumin carrier can provide tumor-targeted drug delivery function. OBJECTIVE:To investigate the effect and mechanism of bovine serum albumin-chitosan nanoparticles loaded with EPZ6438(EZH2 inhibitor)for the treatment of osteosarcoma. METHODS:(1)Bovine serum albumin-chitosan nanoparticles loaded with and without EPZ6438 were prepared.The drug encapsulation rate and drug release rate of serum albumin-chitosan nanoparticles loaded with EPZ6438 were detected.(2)MG-63 cells were divided into four groups and added with PBS(control group),serum albumin-chitosan nanoparticle extract solution(blank nanoparticle group),EPZ6438 solution(free drug group),and serum albumin-chitosan nanoparticle extract loaded with EPZ6438(drug-loaded nanoparticle group),respectively.After 3 days of culture,cell apoptosis was detected by flow cytometry and the expression of caspase-3 mRNA was detected by RT-PCR.(3)Twelve nude mice were selected and the subcutaneous tumor-bearing mouse model was established by injecting MG-63 cell suspension under the armpit.After successful modeling,the mice were randomly divided into four groups for intervention.Normal saline(control group),serum albumin-chitosan nanoparticle solution(blank nanoparticle group),EPZ6438 solution(free drug group)and serum albumin-chitosan nanoparticle solution loaded with EPZ6438(drug-loaded nanoparticle group)were injected into tumor tissues,with three animals in each group.After 7 days of injection,the tumor volume and frozen sections of tumor tissue were observed by TUNEL staining. RESULTS AND CONCLUSION:(1)The drug encapsulation rate of the nanoparticles was about 8.8%,and the nanoparticles had a good drug release effect in pure water.The drug release amount was(34.72±1.93)μg at 24 hours,(48.58±1.10)μg at 72 hours,(49.18±1.24)μg at 120 hours,and(50.25±1.13)μg at 168 hours.The drug release reached the plateau at 120 hours,and the release rate was about 97.9%.(2)After 3 days of cell culture with MG-63,the apoptotic rate in the control group and blank nanoparticle group was lower than that in the free drug group and drug-loaded nanoparticle group(P<0.001),and the expression of caspase 3 mRNA was lower than that in the free drug group and drug-loaded nanoparticle group(P<0.000 1).(3)After 7 days of injection,the tumor volume of nude mice in the drug-loaded nanoparticle group was smaller than that in the other three groups(P<0.05),and the percentage of TUNEL-positive cells in tumor tissue was higher than that in the other three groups(P<0.000 1).(4)The results verify that serum albumin-chitosan nanoparticles loaded with EPZ6438 can inhibit the growth of osteosarcoma by inducing apoptosis of tumor cells.

Objective To explore clinical effect of vancomycin calcium sulfate combined with internal fixation on cal-caneal beak-like fracture secondary to calcaneal osteomyelitis caused by diabetic foot.Methods From April 2018 to October 2021,a retrospective analysis was performed on 5 patients with calcaneal bone osteomyelitis secondary to diabetic foot,includ-ing 2 males and 3 females,aged from 48 to 60 years old;diabetes course ranged from 5 to 13 years;the courses of diabetic foot disease ranged from 18 to 52 days;5 patients were grade Ⅲ according to Wagner classification.All patients were treated with debridement,vancomycin bone cement implantation,negative pressure aspiration at stage Ⅰ,vancomycin calcium sulfate and internal fixation at stage Ⅱ for calcaneal beak-like fracture.Surgical incision and fracture healing time were recorded,and the recurrence of osteomyelitis was observed.American Orthopedic Foot Andankle Society(AOFAS)score and exudation at 12 months after operation were evaluated.Results Five patients were successfully completed operation without lower extremity vascular occlusion,and were followed up for 16 to 36 months.The wound healing time after internal fixation ranged from 16 to 26 days,and healing time of fractures ranged from 16 to 27 weeks.AOFAS score ranged from 65 to 91 at 12 months after oper-ation,and 2 patients got excellent result,2 good and 1 fair.Among them,1 patient with skin ulcer on the back of foot caused by scalding at 5 months after operation(non-complication),was recovered after treatment;the wound leakage complication oc-curred in 2 patients,and were recovered after dressing change.No osteomyelitis or fracture occurred in all patients.Conclusion Vancomycin calcium sulfate with internal fixation in treating calcaneal osteomyelitis secondary to calcaneal osteomyelitis caused by diabetic foot could not only control infection,but also promote fracture healing,and obtain good clinical results.

In the present study, liquiritigenin-phospholipid complex (LPC) was developed and evaluated to increase the oral bioavailability of liquiritigenin. A single-factor test methodology was applied to optimize the formulation and process for preparing LPC. The effects of solvent, drug concentration, reaction time, temperature and drug-to-phospholipid ratio on encapsulation efficiency were investigated. LPCs were characterized by UV-visible spectroscopy, differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), and powder X-ray diffractometry (PXRD). The apparent solubility and n-octanol/water partition coefficient were tested. The pharmacokinetic characteristics and bioavailability of the LPC were investigated after oral administration in rats in comparison with liquiritigenin alone. An LPC was successfully prepared. The optimum level of various parameters for liquiritigenin-phospholipid complex was obtained at the drug concentration of 8 mg·mL
Administration, Oral ; Animals ; Biological Availability ; Flavanones/pharmacokinetics* ; Phospholipids/pharmacokinetics* ; Rats ; Solvents

Cyclophosphamide (CPA) is one of the most commonly used alkylating agents in the treatment of malignant cancer. CPA is metabolized by cytochrome P450 enzymes into 4-hydroxycyclophosphamide in vivo which can exhibit anti-tumor activity. Metabolic activation of CPA can cause adverse reactions such as myelosuppression, cystitis, and liver injury. The aim of this study was to evaluate the dynamic changes of hepatic injury induced by CPA in mice. Male BALB/c mice were injected CPA (200 mg·kg^-1) intraperitoneally. Both serum and liver samples were collected at 0, 2, 6, 12 and 24 hours after dosing. The animal experiment protocol was approved by the Institutional Animal Care and Use Committee at Sun Yat-sen University. The results showed that hepatotoxicity was observed at 2 hours after CPA dosing, and the most serious liver injury was measured at 12 hours. The level of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and malondialdehyde (MDA) was significantly increased, glutathione (GSH) level was significantly decreased, hepatocyte edema and vacuolar degeneration were widely observed in liver tissue, and began to recover 24 hours after dosing. In addition, due to oxidative stress damage caused by CPA, nuclear factor-erythroid 2-related factor 2 (NRF2) signaling pathway was activated and the mRNA and protein expression of its downstream targets such as quinine oxidoreductase 1 (NQO1), heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic subunit (GCLC) and glutamate cysteine modifier subunit (GCLM) were up-regulated, which alleviated oxidative stress injury. In a summary, this study demonstrate the dynamic change of CPA-induced liver injury and the NRF2-mediated protective mechanisms, providing new insights into the CPA-induced liver injury.