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.

Pulmonary electrical impedance tomography (EIT), a noninvasive, continuous, dynamic, and radiation-free bedside imaging technique for monitoring pulmonary ventilation, is now widely utilized in the diagnosis and management of critically ill patients. Beyond ventilation monitoring, hypertonic saline contrast-enhanced EIT for bedside pulmonary perfusion assessment has recently garnered significant attention. This article describes the application of hypertonic saline contrast-enhanced EIT to evaluate pulmonary perfusion in two patients following pulmonary endarterectomy, providing a reference for its perioperative application in such patients.

Objective The volume and cortical thickness of gray matter in patients with multiple sclerosis (MS) and neuromyelitis optica (NMO) were compared and analyzed by voxel⁃based morphometry (VBM) and surface⁃based morphometry (SBM), and the differences in the structural changes of gray matter in the two diseases were discussed. Methods A total of 21 MS patients, 16 NMO patients and 19 healthy controls were scanned by routine MRI sequence. The data were processed and analyzed by VBM and SBM method based on the statistical parameter tool SPM12 of Matlab2014a platform and the small tool CAT12 under SPM12. Results Compared with the normal control group (NC), after Gaussian random field (GRF) correction, the gray matter volume in MS group was significantly reduced in left superior occipital, left cuneus, left calcarine, left precuneus, left postcentral, left central paracentral lobule, right cuneus, left middle frontal, left superior frontal and left superior medial frontal (P<0. 05). After family wise error (FWE) correction, the thickness of left paracentral, left superiorfrontal and left precuneus cortex in MS group was significantly reduced (P<0. 05). Compared with the NC group, after GRF correction, the gray matter volume in the left postcentral, left precentral, left inferior parietal, right precentral and right middle frontal in NMO group was significantly increased (P<0. 05). In NMO group, the volume of gray matter in left middle occipital, left superior occipital, left inferior temporal, right middle occipital, left superior frontal orbital, right middle cingulum, left anterior cingulum, right angular and left precuneus were significantly decreased (P<0. 05). Brain regions showed no significant differences in cortical thickness between NMO groups after FWE correction. Compared with the NMO group, after GRF correction, the gray matter volume in the right fusiform and right middle frontal in MS group was increased significantly(P<0. 05). In MS group, the gray matter volume of left thalamus, left pallidum, left precentral, left middle frontal, left middle temporal, right pallidum, left inferior parietal and right superior parietal were significantly decreased (P<0. 05). After FWE correction, the thickness of left inferiorparietal, left superiorparietal, left supramarginal, left paracentral, left superiorfrontal and left precuneus cortex in MS group decreased significantly (P<0. 05). Conclusion The atrophy of brain gray matter structure in MS patients mainly involves the left parietal region, while NMO patients are not sensitive to the change of brain gray matter structure. The significant difference in brain gray matter volume between MS patients and NMO patients is mainly located in the deep cerebral nucleus mass.

Objective To construct reference ranges of cardiac size and morphologic parameters in low-risk fetuses at 28-39 gestational weeks using two-dimensional speckle tracking technique.Methods A prospective collection of 453 low-risk singleton pregnancies with echocardiography at Obstetrics and Gynecology Hospital,Fudan University was used to assess the size(length,width,and area)and morphology(sphericity index,i.e.,the ratio of length to width)of the fetal four-chamber view and two ventricles using two-dimensional speckle tracking technique.Repeated inter-and intra-observer agreement of measurements was assessed using the intraclass correlation coefficients(ICCs).Statistical analysis of cardiac measurement parameters was performed to establish reference ranges of values for cardiac size and morphology in low-risk fetuses.Results The inter-and intra-group ICCs for reproducibility tests of fetal cardiac parameters measurements were 0.691 to 0.980.Fetal four-chamber view and ventricular size increased with gestational week(all P<0.001),the end-diastolic length of the left ventricle was larger than that of the right ventricle,and the end-diastolic diameter was smaller than that of the right ventricle(both P<0.001),while there was no significant difference in the end-diastolic area of the two ventricles(P= 0.050).The spherical index of four-chamber view did not correlate with gestational week(P=0.811).The sphericity index of the basal and intermediate segments of the left ventricle was greater than that of the right ventricle,and the sphericity index of the apical segment was less than that of the right ventricle,the differences were statistically significant(all P<0.01).Conclusion The two-dimensional speckle tracking technique for measuring fetal cardiac parameters has good reproducibility.The reference ranges for cardiac size and morphology in low-risk fetuses developed in this study will be useful for prenatal evaluation of cardiac remodeling.

As the predominant toxic constituent within the Aconitum genus, Aconitum alkaloids (ATs) exhibit both significant pharmaceutical value and substantial toxicity, have been widely used in traditional Chinese medicine and the realm of contemporary clinical medicine. However, owing to their high toxicity, inappropriate employment of ATs in pharmaceuticals, edibles, and the environment will pose serious threats to human health, inciting a series of toxic incidents. Consequently, it is very important to develop effective analytical methods. This paper presents a comprehensive review of the advancements in research pertaining to the pretreatment and detection methods in common substrates, including high performance liquid chromatography, liquid chromatography-mass spectrometry and rapid detection methods. To explore the specific sources of ATs in actual poisoning cases, the comprehensive traceability strategy based on plant morphology, chemical fingerprint analysis and DNA barcoding technology was discussed, proposing a comprehensive prospect for the development of ATs analysis and traceability, in order to provide guidance for related research within the forensic science domain.

AIM To study the extraction process,enzymatic properties and practical application of glucuronic hydrolase in Scutellaria baicalensis stems and leaves(sbsl GUS).METHODS With granularity,water consumption,extraction time and extraction frequency as influencing factors,enzymatic activity as an evaluation index,the extraction process was optimized by orthogonal test on the basis of single factor test.The relationship between substrate(baicalin)concentration and enzymolysis rate,after which Vmax and Km were calculated,the effects of pH value,temperature and metal ion on enzymatic activity were investigated,pH stability and heat stability were evaluated.sbsl GUS was adotped in the enzymolysis of baicalin to prepare baicalein,then the effects of pH value,temperature,reaction time,initial substrate concentration and enzyme addition on transfer rate were investigated.RESULTS The optimal extraction process was determined to be 40 mesh for granularity,10 times for water consumption,15 min for extraction time,and 3 times for extraction frequency.The enzymolysis accorded with the kinetics of enzymatic reaction,Km was 0.006 3 mol/L,Vmax was 70.42 μmol/h,the strongest enzymatic activity was found at the pH value of 6.0,temperature of 45℃and metal ion of 100 mmol/L Cu2+,sbsl GUS demonstrated good stability at the ranges of 4.0-7.0 for pH value and 4-30℃for temperature.The optimal preparation process was determined to be 6.0 for pH value,45℃for temperature,more than 12 h for reaction time,67.2 mmol/L for initial substrate concentration,and 1 mL/0.269 mmol baicalin for enzyme addition,the transfer rate was 97.83%.CONCLUSION sbsl GUS enzymolysis exhibits high efficiency and mild condition,which can provide a simple preparation method for obtaining baicalein,and expand the application path of Scutellaria baicalensis stems and leaves.

Objective To investigate the effects of palmatine on migration,invasion and epithelial mesenchymal transformation(EMT)in human oral cancer KB cells.Methods KB cells were divided into control group and palmatine-L,-M,-H groups,cultured with 0,4,8 and 16 μmol·L-1 palmatine.After incubation for 48 h,scratch assay was used to detect migration;Traswell assay was used to detect invasion;matrix metalloproteinase 2(MMP-2),MMP-9 and fibronectin(FN)contents were detected by enzyme-linked immunosorbent assay;the expression of Vimentin,N-cadherin and E-cadherin mRNA were detected by real-time quantitative polymerase chain reaction;the expression of Vimentin,N-cadherin,E-cadherin,Wnt3 and β-catenin protein were detected by Western blot.Results Cell mobility in control group and palmatine-L,-M,-H groups were(69.27±8.62)％,(52.94±4.49)％,(45.22±5.05)％and(37.63±4.88)％;the number of transmembrane cells were 197.33±20.26,125.33±12.01,97.00±9.17 and 62.67±7.51;the content of MMP-2 were(2.93±0.21),(1.49±0.13),(1.16±0.15)and(0.95±0.09)ng·mL-1;the content of MMP-9 were(3.51±0.36),(2.37±0.23),(2.06±0.35)and(1.72±0.16)ng·mL-1;the content of FN were(41.28±4.02),(24.03±3.17),(20.67±2.63)and(13.82±2.19)ng·mL-1;the above indexes in palmatine-L,-M,-H groups were compared with the control group,and the differences were statistically significant(P＜0.05,P＜0.01).The mRNA and protein expressions of Vimentin,N-cadherin and E-cadherin,and the expressions of Wnt3 and β-catenin protein in palmatine-L,-M,-H groups were statistically significant compared with those in control group(P＜0.05,P＜0.01).Conclusion Palmatine can inhibit the migration,invasion and EMT of human oral cancer KB cells,and its mechanism is related to the regulation of Wnt/β-catenin signaling pathway.

Objective:This study investigated the efficacy and safety of denosumab (DENOS) versus zoledronic acid (ZOL) in the bone disease treatment of newly diagnosed multiple myeloma.Methods:The clinical data of 80 patients with myeloma bone disease (MBD) at the Fifth Medical Center of PLA General Hospital between March 1, 2021 and June 30, 2023 were retrospectively reviewed. Eighteen patients with severe renal impairment (SRI, endogenous creatinine clearance rate<30 ml/min) were treated with DENOS, and 62 non-SRI patients were divided into DENOS (30 patients) and ZOL group (32 patients) .Results:Hypocalcemia was observed in 26 (33%) patients, and 22 patients developed hypocalcemia during the first treatment course. The incidence of hypocalcemia in the non-SRI patients of DENOS group was higher than that in the ZOL group [20% (6/30) vs 13% (4/32), P=0.028]. The incidence of hypocalcemia in SRI was 89% (16/18). Multivariate logistic regression analysis revealed that endogenous creatinine clearance rate<30 ml/min was significantly associated with hypocalcemia after DENOS administration ( P<0.001). After 1 month of antiresorptive (AR) drug application, the decrease in the serum β-C-terminal cross-linked carboxy-telopeptide of collagen type I concentrations of SRI and non-SRI patients in the DENOS group were significantly higher than that in the ZOL group (68% vs 59% vs 27%, P<0.001). The increase in serum procollagen type Ⅰ N-terminal propeptide concentrations of patients with or without SRI in the DENOS group were significantly higher than that in the ZOL group (34% vs 20% vs 11%, P<0.05). The level of intact parathyroid hormone in each group increased after AR drug treatment. None of the patients developed osteonecrosis of the jaw and renal adverse events, and no statistically significant differences in the overall response rate, complete remission and stringent complete remission rates were found among the groups ( P>0.05), and the median PFS and OS time were not reached ( P>0.05) . Conclusions:In the treatment of MBD, DENOS minimizes nephrotoxicity and has strong AR effect. Hypocalcemia is a common adverse event but is usually mild or moderate and manageable.

Objective:To discuss the effect of temperature-controlled shrinkage polytrimethylene carbonate(PTMC)/polyvinylpyrrolidone(PVP)nanofiber membrane on the biological behavior of mouse fibroblasts and the repairment effect on full-thickness skin defects in the rats,and to clarify the potential mechanism.Methods:The murine L929 fibroblast cells were used in the in vitro experiments and were divided into control group and experimental group(treated with PTMC/PVP nanofiber membranes).The proliferation activities of the cells in two groups were detected by CCK-8 assay;the numbers of live/dead cells in two groups were observed by live/dead cell staining;the morphology of the cells was observed by cytoskeletal staining.A total of 12 six-week-old male SD rats were selected in the in vivo experiment,and were randomly divided into control group and experimental group,and there were six rats in each group.The full-thickness skin defect model was established,and the rats in experimental group were treated with PTMC/PVP nanofiber membranes.The photographs were taken after operation,and the wound healing rates of the cells in two groups were calculated on the 0,3rd,6th,and 12th days.On the 6th and 12th days after operation,the skin samples around the wound of the rats in two groups were taken,and the histopathology of the would skin and adjacent tissue was detected by HE staining;the collagen deposition in wound skin tissue of the rats in two groups was observed by Masson trichrome staining;the numbers of angiogenesis in wound skin tissue of the rats were detected by CD31 immunohistochemical staining.Results:The CCK-8 assay results showed that the proliferation activity of the cells in experimental group showed an increasing trend on the 1st,3st,and 5st days,and there was no significant difference in the proliferation activities of the cells bewteen experimental group and control group(P＞0.05).The live/dead cell staining experiment results showed that compared with control group,the cell density and number of the cells in experimental group had no significant changes,and were predominantly live cells.The cytoskeletal staining results showed that the cells in experimental and control groups appeared spindle-shaped and well-spread.In the in vivo experiments,on the 3rd,6th,and 12th days,compared with control group,the wound healing rates of the cells in experimental group were increased(P＜0.01),and the wound healing rate of the cells was 95.45％on the 12th day,indicating nearly complete healing of the wound.The HE staining showed that on the 12th day,the wound skin structure of the cells in experimental group was more similar to the normal skin,and there was abundant granulation tissue,regular epidermal structure,and new blood vessel formation.The Masson trichrome staining results showed that compared with control group,the collagen deposition in wound tissue of the rats in experimental group was increased.The immunohistochemical staining results showed that the expression of CD31 in wound tissue of the rats in experimental group was increased,indicating the increasing of the number of angiogenesis.Conclusion:The PTMC/PVP thermoresponsive nanofiber membranes exhibit good biocompatibility and can promote the repairment of full-thickness skin defects in the rats;its mechanism may be related to the enhancement of proliferation activity of the basal cells.

Surface-enhanced Raman scattering(SERS)can detect molecules adsorbed on the surface of noble metals in monolayers and sub-monolayers,and provide structural information of molecules with high sensitivity,high accuracy,and fingerprint recognition and non-destructive detection.The SERS technology has been widely used in single-molecule detection,chemical reaction and engineering,biomedicine,nanomaterials and environmental detection,and so on.The spectral sensitivity and signal reproducibility of SERS are closely related to the type of noble metal substrate.In this paper,based on the mechanism of electromagnetic field enhancement(EM)and chemical enhancement(CM)of SERS,the affecting factors of SERS enhancement were analyzed,including the micro-nanostructure of SERS substrate,particle size,particle spacing,etc,the research and application of SERS substrate in recent years were summarized and reviewed,and the development direction of metal substrate,data analysis and application direction of SERS technology in the future were prospected.