Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

ObjectiveTo investigate the mechanism of Huazhuo Jiedu prescription in treating ulcerative colitis （UC） by regulating mitophagy. MethodsThe genes related to mitophagy and UC were retrieved from GeneCards， and then the common genes of mitophagy and UC were analyzed by metascape to identify the genes related to mitophagy in UC. Animal experiments were carried out to decipher the mechanism by which Huazhuo Jiedu prescription treated UC by regulating mitophagy. Sixty C57BL/6 male mice were randomized into normal， model， high-， medium-， and low-dose （50， 25， 12.5 g·kg^-1， respectively） Huazhuo Jiedu prescription， and mesalazine （0.52 g·kg^-1·d^-1） groups， with 10 mice in each group. After successful modeling by the dextran sulfate sodium-free drinking method， the colonic mucosal damage was observed by hematoxylin-eosin staining， and the ultracellular structure of colon mucosa was observed by transmission electron microscopy. The expression levels of mitophagy-related proteins PTEN-induced putative kinase 1 （PINK1） and Parkin protein were determined by Western blot. The expression of prohibitin 2 （PHB2）， ubiquitin-specific protease 15 （USP15）， ubiquitin-specific protease 30 （USP30） in the colon tissue was detected by immunofluorescence （IF）. ResultsAll the drug intervention groups showed ameliorated pathological manifestations of the colonic mucosa and improved mitochondrial structures in UC mice. Compared with the normal group， the model group demonstrated up-regulated protein levels of PINK1 and Parkin （P<0.05）， enhanced average fluorescence intensity of PHB2 （P<0.05）， and weakened average fluorescence intensity of USP15 and USP30 （P<0.05）. Compared with the model group， the mesalazine group and the high- and medium-dose Huazhuo Jiedu prescription groups showcased down-regulated protein levels of PINK1 and Parkin （P<0.05）， decreased average fluorescence intensity of PHB2 （P<0.05）， and enhanced average fluorescence intensity of USP15 and USP30 （P<0.05）. The low-dose Huazhuo Jiedu prescription group showed down-regulated protein levels of PINK1 and Parkin （P<0.05）， weakened average fluorescence intensity of PHB2 （P<0.05）， and enhanced average fluorescence intensity of USP15 and USP30 （P<0.05）. ConclusionHuazhuo Jiedu prescription can attenuate the intestinal mucosal injury and improve the mitochondrial cell ultrastructure in UC mice by regulating the expression of PINK1-Parkin pathway and inhibiting excessive mitophagy.

ObjectiveTo investigate the mechanism of Huazhuo Jiedu prescription in treating ulcerative colitis （UC） by regulating mitophagy. MethodsThe genes related to mitophagy and UC were retrieved from GeneCards， and then the common genes of mitophagy and UC were analyzed by metascape to identify the genes related to mitophagy in UC. Animal experiments were carried out to decipher the mechanism by which Huazhuo Jiedu prescription treated UC by regulating mitophagy. Sixty C57BL/6 male mice were randomized into normal， model， high-， medium-， and low-dose （50， 25， 12.5 g·kg^-1， respectively） Huazhuo Jiedu prescription， and mesalazine （0.52 g·kg^-1·d^-1） groups， with 10 mice in each group. After successful modeling by the dextran sulfate sodium-free drinking method， the colonic mucosal damage was observed by hematoxylin-eosin staining， and the ultracellular structure of colon mucosa was observed by transmission electron microscopy. The expression levels of mitophagy-related proteins PTEN-induced putative kinase 1 （PINK1） and Parkin protein were determined by Western blot. The expression of prohibitin 2 （PHB2）， ubiquitin-specific protease 15 （USP15）， ubiquitin-specific protease 30 （USP30） in the colon tissue was detected by immunofluorescence （IF）. ResultsAll the drug intervention groups showed ameliorated pathological manifestations of the colonic mucosa and improved mitochondrial structures in UC mice. Compared with the normal group， the model group demonstrated up-regulated protein levels of PINK1 and Parkin （P<0.05）， enhanced average fluorescence intensity of PHB2 （P<0.05）， and weakened average fluorescence intensity of USP15 and USP30 （P<0.05）. Compared with the model group， the mesalazine group and the high- and medium-dose Huazhuo Jiedu prescription groups showcased down-regulated protein levels of PINK1 and Parkin （P<0.05）， decreased average fluorescence intensity of PHB2 （P<0.05）， and enhanced average fluorescence intensity of USP15 and USP30 （P<0.05）. The low-dose Huazhuo Jiedu prescription group showed down-regulated protein levels of PINK1 and Parkin （P<0.05）， weakened average fluorescence intensity of PHB2 （P<0.05）， and enhanced average fluorescence intensity of USP15 and USP30 （P<0.05）. ConclusionHuazhuo Jiedu prescription can attenuate the intestinal mucosal injury and improve the mitochondrial cell ultrastructure in UC mice by regulating the expression of PINK1-Parkin pathway and inhibiting excessive mitophagy.

Elderly end-of-life patients often experience distress due to being caught in dilemmas of contemplation and decision-making. Narrative wills， grounded in life values and premised on respecting individual wishes and needs， present an individual’s unique life story through narrative forms， conveying their overall experience， interpretation of meaning， and understanding of life. They are preserved and passed on in a way that meets individual expectations， thereby promoting human exploration， reflection， and growth regarding the meaning of life through interpersonal interactions that transcend space and time. This paper explored the concept of narrative wills among elderly end-of-life patients， the ethical value and ethical principles of narrative wills， and the moral and ethical risks. It also provided specific ethical interpretations， assisting in the application and development of narrative wills in elderly end-of-life patients.

Objective: To explore the effects of Cldn14 gene knockout on renal metabolism and stone formation in rats，so as to provide reference for research in the field of urinary calium metabolism and stone formation. Methods: Cldn14 gene knockout homozygous rats and wild-type rats of the same age were randomly divided into 4 groups：wild-type control (WC) group，wild-type ethylene glycol (WE) group，gene knockout control (KC) group and gene knockout ethylene glycol (KE) group，with 10 rats in each group.The WE and KE groups were induced with ethylene glycol + ammonium chloride to form kidney stones，while the WC and KC groups received normal saline gavage.After 4 weeks of standard maintenance feeding，the urine samples were collected to detect the venous blood.The kidneys were collected for HE，Pizzolatto's staining and transmission electron microscopy.The protein in renal tissues was extracted to detect the expressions of Claudin16 and Claudin19. Results: Crystal deposition was observed in the renal tubular lumen of the WE and the KE groups，and more crystals were detected in the KE group.The WE group had a large number of intracytoplasmic black crystalline inclusions observed in renal tubular epithelial cells under transmission electron microscope，followed by the KE and KC groups.Compared with WC and WE groups，KC and KE groups had significantly decreased serum calcium and magnesium levels but significantly increased urinary calcium level.In addition，the urinary calcium level was higher in the WE group than in the WC group and higher in the KE group than in the KC group.The KE group had lower level of Claudin16，but there was no significant difference in the level of Claudin19 among the 4 groups(P>0.05). Conclusion: Knockout of Cldn14 gene alone cannot effectively reduce urinary calcium excretion or reduce the risk of stone formation in rats，which may be related to the decrease of Claudin16 level.

Objective To investigate the inhibitory effect of toosendanin on the growth of lung adenocarcinoma cells in vitro and in vivo by regulating the expression of cell division cycle associated protein 5(CDCA5).Methods The expression of CDCA5 in different lung tissues was analyzed in TCGA database.The expression level of CDCA5 in BEAS-2B cells and A549 cells was detected by Western blot.The effect of different concentrations of toosendanin on the viability of A549 cells was determined by cell counting kit-8(CCK-8)assay.The A549 cells were randomly divided into 4 groups:control group(normal cells cultured normally),toosendanin group(normal cells cultured with 40 μmol·L-1 toosendanin),toosendanin+pcDNA group(cells transfected with pcDNA empty vector and cultured with 40 μmol·L-1 toosendanin),and toosendanin+CDCA5 group(cells transfected with CDCA5 overexpression vector and cultured with 40 μmol·L-1 toosendanin).After 48 h of cultivation,the proliferation and apoptosis of each group of cells were detected by CCK-8 and flow cytometry,and the expression of proliferation and apoptosis related proteins in each group of cells was detected by Western blot.The BALB/c nude mice were randomly divided into sh-NC and sh-CDCA5 stable transfected cell lines with nude mouse xenograft models.Daily intraperitoneal injection of 0.9％NaCl and 40μmol·L-1 toosendanin solution was given to observe and record the changes in tumor tissue volume and body mass.Results The results of CCK-8 showed that after 48 hours,the survival rates of A549 cells treated with 10,20,30,40,50,60 and 70 μmol·L-1 toosendanin were(80.74±8.71)％,(72.96±6.53)％,(61.01±4.86)％,(51.20±3.13)％,(42.10±5.94)％,(38.93±3.18)％and(33.48±2.94)％,respectively.Toosendanin significantly inhibited the proliferation of A549 cells.The proliferation rates of cells in the control group,toosendanin group,toosendanin+pcDNA group,and toosendanin+CDCA5 group were(100.00±4.19)％,(49.18±6.70)％,(55.75±5.74)％,and(77.66±7.48)％,respectively;the expression levels of CDCA5 protein were 1.08±0.11,0.44±0.04,0.43±0.05 and 0.99±0.10,respectively.The expression levels of CDCA5 protein in tumor tissues of nude mice in the sh-NC group,sh-CDCA5 group,toosendanin+sh-NC group,and toosendanin+sh-CDCA5 group were 1.04±0.14,0.42±0.04,0.56±0.08 and 0.32±0.04,respectively.Compared with the sh-NC group,the tumor blocks formed by nude mice in other groups were significantly smaller,and the tumor volume and weight were significantly lower(all P＜0.05).Compared with the toosendanin+sh-NC group,the toosendanin+sh-CDCA5 group had more significant inhibitory effect on tumor formation,and the difference was statistically significant(P＜0.05).Conclusion Toosendanin can inhibit the growth of lung adenocarcinoma cells in vitro and in vivo,which is mainly related to the inhibition of CDCA5 expression.

Objective To study the pharmacokinetic characteristics of the test formulation of compound lidocaine cream and reference formulation of lidocaine and prilocaine cream in Chinese healthy subjects and to evaluate whether there is bioequivalence between the two formulations.Methods A single-center,single-dose,randomized,open-label,two-period,two-sequence,crossover design was used.This study included 40 healthy subjects,and in each period,test formulation or reference formulation 60 g was applied to the skin in front of both thighs(200 cm2 each side,a total of 400 cm2)under fasting conditions,and the drug was left on for at least 5 h after application.The concentrations of lidocaine and prilocaine in plasma were determined using liquid chromatography-tandem mass spectrometry(LC-MS/MS)method.Pharmacokinetic parameters were calculated using WinNonlin 8.0 software to evaluate the bioequivalence of the two formulations.Results After the application of the test formulation compound lidocaine cream and the reference formulation lidocaine and prilocaine cream on both thighs of the subjects,the pharmacokinetic parameters of lidocaine in plasma were as follows:Cmax were(167.27±91.33)and(156.13±66.86)ng·mL-1,AUC0-t were(1 651.78±685.09)and(1 636.69±617.23)ng·mL-1·h,AUC0-∞ were(1 669.85±684.65)and(1 654.37±618.30)ng·mL-1·h,the adjusted geometric mean ratios were 104.49％,101.88％and 101.89％,respectively,with 90％confidence intervals of 98.18％-111.20％,97.80％-106.13％and 97.87％-106.07％,all within the range of 80.00％-125.00％.The pharmacokinetic parameters of prilocaine in plasma were as follows:Cmax were(95.66±48.84)and(87.52±39.16)ng·mL-1,AUC0-t were(790.86±263.99)and(774.14±256.42)ng·mL-1·h,AUC0_m were(807.27±264.67)and(792.84±254.06)ng·mL-1 h,the adjusted geometric mean ratios were 107.34％,103.55％and 102.98％,respectively with 90％confidence intervals of 101.69％-113.31％,99.94％-107.30％and 99.65％-106.43％,all within the range of 80.00％-125.00％.Conclusion The test formulation compound lidocaine cream and the reference formulation lidocaine and prilocaine cream are bioequivalent.

Objective To analyze therapeutic effect of savolitinib in patients with stage Ⅲ/Ⅳ non-small cell lung cancer (NSCLC). Methods A total of 95 patients with MET 14 exon (METex14) jumping mutation in stage Ⅲ/Ⅳ NSCLC were divided into a control group (47 cases) and an observation group (48 cases) through a random-number table method. The patients in the control group were treated with crizotinib, whereas those in the observation group were treated with savolitinib. The clinical efficacy and incidence of toxic side effects in both groups were evaluated through a chi-square test, and survival was evaluated through Kaplan-Meier survival analysis. Results Compared with control group (31.91% and 70.21%), the objective response rate and disease control rate of the observation group were 52.08% and 87.50%, respectively (P<0.05). According to Kaplan-Meier survival analysis, the overall survival and progression free survival rates in the observation group were higher than those in the control group (Log rank χ²=8.003, 4.528; P=0.005, 0.033). No statistically significant difference in the degree of toxic side effects was found between the groups (P>0.05). Conclusion Savolitinib can improve the efficacy of treatment for stage Ⅲ/Ⅳ METex14 skip mutation NSCLC patients, prolong survival, enhance the tolerance of patients to savolitinib, and facilitate the management of adverse reactions.

OBJECTIVE To explore the effects of different concentrations of aconitine on the ventricular electrophysiology of the rat heart when applied to the heart. METHODS By optical mapping technology, the effects of different concentrations of aconitine on ventricular action potential and calcium signal in rats before and 15 min after administration were observed by in vitro administration of aconitine 0.3, 1, 3 ng·mL−1. RESULTS Compared with the blank group, aconitine could be concentration-dependent to delay the conduction of action potentials under both spontaneous and 6 Hz stimulation rhythms, and there was a significant difference at a concentration of 3 ng·mL−1(P<0.05 or P<0.01). Compared with blank group, when the concentration of aconitine was 1 and 3 ng·mL−1, the action potential duration(APD) of the ventricle was significantly prolonged(P<0.01). Aconitine could also increase the dispersion of action potential conduction(P<0.05) and reduce the ratio of effective refractory period(ERP) to APD90(P<0.01). In addition, aconitine could also be concentration-dependent delay of calcium signal conduction, reduce the speed of calcium conduction(P<0.05 or P<0.01), increase the dispersion of calcium conduction and calcium transient duration(P<0.05 or P<0.01), and reduce the amplitude of calcium signal(P<0.01). CONCLUSION Using the optical labeling technique, it can be visualized that aconitine induces arrhythmia by concentration-dependent delay of ventricular action potential and calcium signaling in rats.To explore the effects of different concentrations of aconitine on the ventricular electrophysiology of the rat heart when applied to the heart. METHODS By optical mapping technology, the effects of different concentrations of aconitine on ventricular action potential and calcium signal in rats before and 15 min after administration were observed by in vitro administration of aconitine 0.3, 1, 3 ng·mL−1. RESULTS Compared with the blank group, aconitine could be concentration-dependent to delay the conduction of action potentials under both spontaneous and 6 Hz stimulation rhythms, and there was a significant difference at a concentration of 3 ng·mL−1(P<0.05 or P<0.01). Compared with blank group, when the concentration of aconitine was 1 and 3 ng·mL−1, the action potential duration(APD) of the ventricle was significantly prolonged(P<0.01). Aconitine could also increase the dispersion of action potential conduction(P<0.05) and reduce the ratio of effective refractory period(ERP) to APD90(P<0.01). In addition, aconitine could also be concentration-dependent delay of calcium signal conduction, reduce the speed of calcium conduction(P<0.05 or P<0.01), increase the dispersion of calcium conduction and calcium transient duration(P<0.05 or P<0.01), and reduce the amplitude of calcium signal(P<0.01). CONCLUSION Using the optical labeling technique, it can be visualized that aconitine induces arrhythmia by concentration-dependent delay of ventricular action potential and calcium signaling in rats.

Objective To investigate the toxicokinetic differences of 3,4-methylenedioxy-N-methylamphetamine(MDMA)and its metabolite 4,5-methylene dioxy amphetamine(MDA)in rats af-ter single and continuous administration of MDMA,providing reference data for the forensic identifica-tion of MDMA.Methods A total of 24 rats in the single administration group were randomly divided into 5,10 and 20 mg/kg experimental groups and the control group,with 6 rats in each group.The ex-perimental group was given intraperitoneal injection of MDMA,and the control group was given intraperi-toneal injection of the same volume of normal saline as the experimental group.The amount of 0.5 mL blood was collected from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.In the continuous administration group,24 rats were randomly divided into the experi-mental group(18 rats)and the control group(6 rats).The experimental group was given MDMA 7 d by continuous intraperitoneal injection in increments of 5,7,9,11,13,15,17 mg/kg per day,respectively,while the control group was given the same volume of normal saline as the experimental group by in-traperitoneal injection.On the eighth day,the experimental rats were randomly divided into 5,10 and 20 mg/kg dose groups,with 6 rats in each group.MDMA was injected intraperitoneally,and the con-trol group was injected intraperitoneally with the same volume of normal saline as the experimental group.On the eighth day,0.5 mL of blood was taken from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.Liquid chromatography-triple quadrupole tandem mass spectrometry was used to detect MDMA and MDA levels,and statistical software was employed for data analysis.Results In the single-administration group,peak concentrations of MDMA and MDA were reached at 5 min and 1 h after administration,respectively,with the largest detection time limit of 12 h.In the continuous administration group,peak concentrations were reached at 30 min and 1.5 h af-ter administration,respectively,with the largest detection time limit of 10 h.Nonlinear fitting equations for the concentration ratio of MDMA and MDA in plasma and administration time in the single-administration group and continuous administration group were as follows:T=10.362C-1.183,R2=0.974 6;T=7.397 3C-0.694,R2=0.961 5(T:injection time;C:concentration ratio of MDMA to MDA in plasma).Conclusions The toxicokinetic data of MDMA and its metabolite MDA in rats,obtained through single and continuous administration,including peak concentration,peak time,detection time limit,and the relationship between concentration ratio and administration time,provide a theoretical and data foundation for relevant forensic identification.