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 effect of icariin （ICA） on the phenotype of dendritic cells （DCs） in heart tissue of the Dahl salt-sensitive myocardial remodeling model of rats and its regulation on the vitamin D system. MethodsMale Dahl salt-resistant rats were divided into a normal group， and male Dahl salt-sensitive rats were divided into a model group， low-， medium-， and high-dose ICA groups （30， 60， 120 mg·kg^-1·d^-1）， and Vitamin D group （3×10^-5 mg·kg^-1·d^-1）. In addition to the normal group， the other groups were given an 8% high salt diet to establish a myocardial remodeling model and received intragastric administration after successful modelling once a day for six weeks. The dynamic changes in tail artery blood pressure were monitored， and detection of cardiac ultrasound function in rats was performed. Hematoxylin-eosin （HE） staining and Masson staining were used to observe the morphological changes in rat heart tissue. The phenotype of DCs and T helper cell 17 （Th17）/regulatory T cell （Treg） ratio were detected by flow cytometry. The mRNA and protein expression of vitamin D receptor （VDR）， 1α-hydroxylase （CYP27B1）， 24-hydroxylase （CYP24A1）， forkhead frame protein 3 （FoxP3）， solitaire receptor γt （RORγt）， myocardial type Ⅰ collagen （ColⅠ）， and type collagen （ColⅢ） in heart tissue was detected by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot. ResultsCompared with the normal group， the model group showed disordered arrangement and rupture of myocardial cells， nuclear condensation， significant edema of myocardial tissue， significant proliferation of collagen fibers in a network distribution， and a significant increase in tail artery blood pressure， left ventricular end diastolic diameter （LVEDD）， and left ventricular end systolic diameter （LVESD） （P<0.05）. The phenotype of cardiac DCs was CD40， CD80， and CD86， and the levels of major histocompatibility complex Ⅱ （MHC-Ⅱ）， Th17 cells， and Th17/Treg were significantly increased （P<0.05）. The mRNA and protein expression of CYP24A1 and RORγt in the heart， as well as the mRNA expression of ColⅠ and ColⅢ， were significantly increased （P<0.05）. The left ventricular ejection fraction （LVEF）， interventricular septal thickness （IVSD）， and left ventricular posterior wall thickness （LVPWD） were significantly decreased （P<0.05）. The phenotype of cardiac DCs such as CD11， CD11b， and Treg cells， were significantly reduced （P<0.05）， while the mRNA and protein expression of cardiac VDR， CYP27B1， and FoxP3 were significantly decreased （P<0.05）. Compared with the model group， the low-， medium-， and high-dose ICA groups and vitamin D group significantly reduced myocardial cell rupture and nuclear consolidation in rats. The high-dose ICA group and vitamin D group showed a small amount of myocardial cell rupture and nuclear consolidation， improving myocardial fiber arrangement to varying degrees and significantly reducing myocardial fiber rupture and proliferation. The tail artery blood pressure， LVEDD， and LVESD were significantly decreased in the low-， medium-， and high-dose ICA groups and vitamin D group （P<0.05）， and the phenotype of cardiac DCs including CD40， CD80， CD86， MHC-Ⅱ， Th17 cells， and Th17/Treg were significantly decreased （P<0.05）. The mRNA and protein expression of CYP24A1 and RORγt， and the mRNA expression of ColⅠ and ColⅢ in the heart were significantly decreased in the medium- and high-dose ICA groups and vitamin D group （P<0.05）. The LVEF， IVSD， and LVPWD of myocardial remodeling model rats in the low-， medium-， and high-dose ICA groups and vitamin D group were significantly increased （P<0.05）. The phenotypes of cardiac DCs including CD11， CD11b， and Treg cells were significantly increased in the medium- and high-dose ICA groups and the Vitamin D group （P<0.05）. The mRNA and protein expressions of VDR， CYP27B1， and FoxP3 in the heart were significantly increased in the medium- and high-dose ICA groups and vitamin D group （P<0.05）. ConclusionICA can regulate tail artery blood pressure， cardiac structural and functional damage， and myocardial tissue fibrosis and inhibit phenotype and functional maturation of DCs in heart tissue in the myocardial remodeling model of Dahl salt-sensitive rats. It can also affect the gene and protein expression of VDR， CYP24A1， and CYP27B1， achieving its intervention in Th17/Treg balance in the immune process of myocardial remodeling possibly by regulating vitamin D/VDR in heart tissue.

The accumulation of uremic toxins such as urea nitrogen, blood creatinine, and uric acid of patients with renal failure in vivo would lead to aggravated kidney damage. In this study, coated aldehyde oxy-starch (CAO) was used as an adsorbent to investigate its in vitro adsorption performance on renal failure indexes for urea, indoxyl sulfate (INS), monomethylamine (MMA), dimethylamine (DMA), uric acid (UA), and creatinine (Cr). The effects of variables such as pH, temperature, concentration, dosage, and time on the adsorption capacity of CAO were systematically investigated, employing analytical techniques of high-performance liquid chromatography (HPLC) and gas chromatography (GC). The results revealed that CAO exhibited a strong adsorption capacity for urea, INS, and MMA, alongside a moderate adsorption capacity for DMA, UA, and Cr. The adsorption kinetics and thermodynamic studies indicated that the adsorption of urea and UA by CAO were fitted in pseudo-first-order kinetics, and the adsorption isotherm aligned with the Freundlich adsorption model. The enthalpy change ΔH of urea in adsorption was in the range of 40 to 60 kJ·mol^-1, which demonstrated the presence of strong adsorption force due to the interactions of coordinating groups. The ΔH of UA was greater than 80 kJ·mol^-1, indicating the generation of chemical bonds during the adsorption. Both of them, Gibbs free energy ΔG was less than 0, within the range of -20 to 0 kJ·mol^-1, suggested that the adsorption of urea and UA by CAO occurred spontaneously as physical adsorption process. The adsorption entropy ΔS of urea and UA was > 0, which indicated an increase in entropy throughout the adsorption. The infrared spectroscopygram showed the formation of a chemical bond, specifically the imine bond, following the adsorption of urea by CAO, thereby indicating a chemical reaction during the adsorption. This study elucidates the adsorption mechanism of CAO on various indexes of renal failure, providing a scientific basis for its clinical usage.

Humans ; Vascular Stiffness ; Coal Mining ; Occupational Diseases/epidemiology* ; Risk Factors ; Coal ; Miners

Acupuncture, a therapeutic treatment defined as the insertion of needles into the body at specific points (ie, acupoints), has growing in popularity world-wide to treat various diseases effectively, especially acute and chronic pain. In parallel, interest in the physiological mechanisms underlying acupuncture analgesia, particularly the neural mechanisms have been increasing. Over the past decades, our understanding of how the central nervous system and peripheral nervous system process signals induced by acupuncture has developed rapidly by using electrophysiological methods. However, with the development of neuroscience, electrophysiology is being challenged by calcium imaging in view field, neuron population and visualization in vivo. Owing to the outstanding spatial resolution, the novel imaging approaches provide opportunities to enrich our knowledge about the neurophysiological mechanisms of acupuncture analgesia at subcellular, cellular, and circuit levels in combination with new labeling, genetic and circuit tracing techniques. Therefore, this review will introduce the principle and the method of calcium imaging applied to acupuncture research. We will also review the current findings in pain research using calcium imaging from in vitro to in vivo experiments and discuss the potential methodological considerations in studying acupuncture analgesia.
Calcium ; Acupuncture Therapy ; Acupuncture ; Acupuncture Analgesia/methods* ; Acupuncture Points ; Technology

In order to understand the status quo of ethical review of clinical research on the defecation function of patients with rectal cancer after sphincter-preserving surgery, analyze its causes and put forward corresponding suggestions, to arouse researchers’ attention to ethical review in subsequent relevant clinical studies. The ethical review of literatures related to the defecation function of patients with rectal cancer after sphincter-preserving surgery published on CNKI in recent 10 years was sorted out and summarized. The results showed that the ethical review of clinical research papers on defecation function of patients with rectal cancer after sphincter-preserving surgery was not optimistic. We should strengthen the ethical training of researchers, improve the ethical awareness of researchers, strictly implement the ethical norms of paper publication, strengthen the ethical requirements of manuscript contracts, perfect the ethical review system, and pay attention to the examination and supervision of informed consent, so as to promote the construction of ethical examination and approval norms of clinical research documents.

Due to the high similarity with the lipid layer between human skin keratinocytes, functional cosmetics with layered liquid crystal structure prepared by liquid crystal emulsification technology encapsulating natural active substances have become a hot research topic in recent years. This type of functional cosmetic often has a fresh and natural skin feel, excellent skin barrier repair function and efficient moisturizing effect, etc., showing great potential in cosmetic application. However, the present research on the application of liquid crystal emulsification technology to functional cosmetics is still in the initial stage, and there are fewer relevant reports with reference values. Based on the mentioned above, this review provides a comprehensive summary of functional cosmetics with layered liquid crystal structures prepared by liquid crystal emulsification technology from the following aspects: the structure of human skin, the composition of lamellar liquid crystal, the advantages of liquid crystal emulsification technology containing natural active substances used in the field of functional cosmetics, the preparation process, main components, influencing factors during the preparation and the market functional cosmetics with lamellar liquid crystal structure. Finally, the prospect of the application of liquid crystal emulsification technology in functional cosmetics is presented, to provide useful references for those engaged in the research of liquid crystal emulsification technology-related functional cosmetics.

A derivatizaton method combined with gas chromatography-mass spectrometry(GC-MS)was established for detection of isobutyl chloroformate(IBCF)residue in active pharmaceutical ingredient of agatroban.The extraction and derivatization reagents,derivatization time,qualitative and quantitative ions were selected and optimized,respectively.The possible mechanism of derivatization and characteristic fragment ions fragmentation were speculated.The agatroban samples were dissolved and extracted by methanol,and the residual IBCF was derived with methanol to generate methyl isobutyl carbonate(MIBCB).After 24 h static derivatization at room temperature,IBCF was completely transformed into MIBCB,which could be used to indirectly detect IBCF accurately.The results showed that the linearity of this method was good in the range of 25-500 ng/mL(R2=0.9999).The limit of detection(LOD,S/N=3)was 0.75 μg/g,and the limit of quantification(LOQ,S/N=10)was 2.50 μg/g.Good recoveries(95.2%-97.8%)and relative standard deviations(RSDs)less than 3.1%(n=6)were obtained from agatroban samples at three spiked levels of IBCF(2.50,25.00,50.00 μg/g),which showed good accuracy of this method.Good precision of detection results was obtained by different laboratory technicians at different times,the mean value of spiked sample solution(25.00 μg/g)was 24.28 μg/g,and the RSD was 2.1%(n=12).The durability was good,minor changes of detection conditions had little effect on the results.Under the original condition and conditions with initial column temperature±5℃,heating rate±2℃/min,column flow rate±0.1 mL/min,the IBCF content of spiked sample solution(25.00 μg/g)was detected,the mean value of detection results was 24.16 μg/g,and the RSD was 2.2%(n=7).Eight batches of agatroban samples from two manufacturers were detected using the established method,and the results showed that no IBCF residue was detected in any of these samples.The agatroban samples could be dissolved by methanol,and then the IBCF residue could be simultaneously extracted and derived with methanol as well.This detection method had the advantages of simple operation,high sensitivity,low matrix effect and accurate quantification,which provided a new effective method for detection of IBCF residue in agatroban.

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.

ObjectiveTo investigate the effect of icariin （ICA）-mediated vitamin D system on peripheral blood dendritic cells （DCs） and helper T cells 17 （Th17）/regulatory T cells （Treg） balance in myocardial remodeling model of Dahl salt-sensitive rats. MethodFifty SPF Dahl salt-sensitive rats were divided into model group， vitamin D group （3×10^-5 mg·kg^-1·d^-1）， and high-， medium-， and low-dose ICA groups （120， 60， 30 mg·kg^-1·d^-1）， and 10 Dahl salt-resistant rats were used as normal group. The myocardial remodeling model was established by feeding rats with a high-salt diet containing 8% NaCl. After six weeks of modeling， the normal group and the model group were given an equal volume of ultrapure water by gavage， and other groups were continuously administrated for six weeks. Cardiac echocardiography， hematoxylin-eosin （HE） staining， and Masson staining were used to observe the pathological changes in cardiac structure and fibrosis. The levels of serum 25（OH）D₃， B-type N-terminal pro-brain natriuretic peptide （NT-ProBNP）， interleukin （IL）-17， transforming growth factor （TGF）-β₁， IL-12， and IL-10 were detected by enzyme-linked immunosorbent assay （ELISA）. The phenotype of peripheral blood DCs and the ratio of Th17/Treg cells of rats were detected by flow cytometry. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot were used to detect the mRNA and protein expressions of vitamin D receptor （VDR），1α-hydroxylase （CYP27B1）， and 24-hydroxylase （CYP24A1） in peripheral blood DCs of rats. ResultCompared with the control group， the rats in the model group had pathological changes such as disordered arrangement of myocardial cells and cytoplasmic hypertrophy and swelling. Myocardial collagen fibers proliferated significantly， and the arrangement of myocardial fibers was disordered. The levels of serum 25（OH）D₃ and IL-10 were significantly decreased， and the levels of serum IL-17， TGF-β₁， IL-6， IL-12， and NT-ProBNP were significantly increased （P<0.05）. The costimulatory molecules CD40， CD80， CD86， and MHC-Ⅱ were highly expressed in the peripheral blood DCs， and the expression of CD11 and CD11b was lower （P<0.05）. The proportion of Th17 cells in the peripheral blood was significantly increased， and the proportion of Treg cells was decreased. The ratio of Th17/Treg was increased （P<0.05）. The mRNA and protein expressions of CYP24A1 in peripheral blood DCs increased， and the mRNA and protein expressions of CYP27B1 and VDR decreased （P<0.05）. Compared with the model group， the arrangement of myocardial fibers in each drug administration group was relatively regular， and the swelling of myocardial cells was significantly reduced. The pathological morphology of myocardial tissue was improved to varying degrees. The pathological changes in myocardial tissue were improved and alleviated to varying degrees. The drug could reduce the serum levels of NT-ProBNP， IL-17， TGF-β₁， IL-6， and IL-12 and increase the level of serum 25（OH）D₃ and IL-10 （P<0.05）. The expression of costimulatory molecules CD40， CD80， CD86， and MHC-Ⅱ in the peripheral blood DCs of rats was decreased， and the expression of CD11 and CD11b molecules was increased （P<0.05）. The drug could reduce the proportion of Th17 cells in peripheral blood and the ratio of Th17/Treg cells and increase the proportion of Treg cells （P<0.05）. It could decrease the mRNA and protein expressions of CYP24A1 in peripheral blood DCs of rats and elevate the mRNA and protein expression of VDR and CYP27B1 （P<0.05）. ConclusionICA can regulate the phenotype of peripheral blood DCs and the ratio of Th17/Treg cells by regulating the vitamin D system and play a role in improving myocardial remodeling from the perspective of immune balance.