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.

A growing body of research points out that gut microbiota plays a key role in tumor immunotherapy. By optimizing the composition of intestinal microbiota, it is possible to effectively improve immunotherapy resistance and enhance its therapeutic effect. This article comprehensively analyzes the mechanism of intestinal microbiota influencing tumor immunotherapy resistance, expounds the current strategies for targeted regulation of intestinal microbiota, such as traditional Chinese medicine and plant components, fecal microbiota transplantation, probiotics, prebiotics and dietary therapy, and explores the potential mechanisms of these strategies to improve patients' resistance to tumor immunotherapy. At the same time, the article also briefly discusses the prospects and challenges of targeting intestinal microbiota to improve tumor immunotherapy resistance, which provides a reference for related research to help the strategy research of reversing tumor immunotherapy resistance.

ObjectiveUltra performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry （UPLC-Q-TOF-MS/MS） coupled with network pharmacology and molecular docking was utilized to explore the efficacy and mechanism of action of Ermiao Situ decoction on rats with damp-heat eczema. MethodsA rat model of damp-heat eczema was established by artificial climate chamber intervention combined with sensitization induction by dinitrochlorobenzene （DNCB）， and it was randomly divided into the normal group， the model group， the medium- and high-dose groups of Ermiao Situ decoction （3.40 g·kg^-1 and 6.80 g·kg^-1）， and the prednisone acetate group （2.51 mg·kg^-1）， with eight rats in each group， totalling 46 rats， of which six rats were tested with the drug-containing serum. The chemical analysis of drug-containing serum from rats was carried out by UPLC-Q-TOF-MS/MS， combined with network pharmacology for the prediction of key components， core targets， and signaling pathways， and molecular docking experiments were performed by CB-Dock2 online website. The pharmacological effects of Ermiao Situ decoction in the treatment of damp-heat eczema were investigated by epitaxial indexes combined with the pathologic tissue staining method. The serum levels of gastrin （GAS）， interleukin-4 （IL-4）， and interleukin-13 （IL-13） were measured by enzyme-linked immunosorbent assay （ELISA）. Interleukin-6 （IL-6）， Janus kinase 1 （JAK1）， phosphorylated （p）-JAK1， signal transduction and activation of transcription factor 3 （STAT3）， and p-STAT3 protein expression level was determined by Western bolt. ResultsA total of 19 active ingredients were detected in drug-containing serum samples of rats， which were predicted to act on 198 targets for the treatment of damp-heat eczema， among which the key ingredients included rhodopsin， huangpai alkaloids， and quercetin， and the main core targets included STAT3， tumor necrosis factor （TNF）， and IL-6， which were mainly involved in the cancer signaling pathway， phosphatidylinositol 3-kinase （PI3K）/protein kinase （Akt） signaling pathway， T helper 17 （Th17） cell differentiation signaling pathway， and JAK/STAT signaling pathway. The molecular docking results suggested that the key components had strong binding activities with the core targets IL-6， JAK1， and STAT3 in the JAK/STAT signaling pathway. The results of animal experiments showed that compared with those in the normal group， rats in the model group were depressed. They had loose hair， loose stools， epidermal oozing， vesiculation， and generation of thick scabs in the form of scales， decreased body weight， increased anus temperature and water intake， and increased indexes of the spleen， thymus gland， and stomach （P<0.05， P<0.01）， and the lesion tissue could be seen to be hyperkeratotic， with the aggregation of inflammatory cells and nonsignificant separation of epidermis and dermis. The gastric mucosa was thinned， deficient， and structurally disorganized， and obvious inflammatory cell aggregation was seen. The levels of GAS， IL-4， and IL-13 in serum were significantly reduced （P<0.05， P<0.01）， and the protein expression levels of IL-6， JAK1， p-JAK1， and p-STAT3 in the lesion tissue were significantly increased （P<0.05， P<0.01）. Compared with those in the model group， rats in each administration group had stable mental states， formed feces， a clean perianal area， and basically normal epidermis. Only a small amount of scaly scabs existed， and the rats had body weight increased， with decreased anal temperature and water intake， as well as decreased spleen， thymus， and gastric indexes （P<0.05， P<0.01）. Epidermal thickness was decreased， and epidermal and dermal separation boundaries were obvious， but hyperkeratotic and accumulation of inflammatory cells could still be seen. The thickness of gastric mucosa increased， and the structure was restored to varying degrees. The levels of GAS， IL-4， and IL-13 content in the serum of rats were increased to varying degrees， and the protein expression levels of IL-6， JAK1， p-JAK1， and p-STAT3 in the dermal lesion tissue were significantly decreased （P<0.05， P<0.01）. ConclusionErmiao Situ decoction may exert therapeutic effects on rats with damp-heat eczema by modulating the JAK/STAT signaling pathway.

OBJECTIVE To investigate the antidepressant mechanism of Shugan hewei tang （SGHWT） based on the metabolomics of prefrontal cortex （PFC）-nucleus accumbens （NAc）-ventral tegmental area （VTA） neural circuit. METHODS Male SD rats were randomly divided into blank group， model group， SGHWT low-， medium- and high-dose groups [3.67， 7.34， 14.68 g/（kg·d）， by raw material]， and fluoxetine group [1.58 mg/（kg·d）， positive control]， with 12 rats in each group. Except for the blank group， the depression model was established by chronic unpredictable mild stress combined with individual cage housing in the remaining groups， and the corresponding drug solution or normal saline was administered via gavage during modeling， once a day， for 6 consecutive weeks. After the last administration， the body weight， sucrose preference rate， total moving distance， frequency into the center and immobility time of rats in each group were detected. Samples of PFC， NAc and VTA areas of rats in the blank group， model group， SGHWT medium-dose group and fluoxetine positive control groups were collected，and their histomorphological features were observed， and non-targeted metabolomics analysis （except for fluoxetine group）were performed and validated. RESULTS Compared with model group， the cytolysis， structural damage and other pathological damages in three brain regions of rats were significantly alleviated in each drug group， while their body weight， sucrose preference rate， total moving distance and frequency into the center were all significantly higher or longer （P＜0.05）， and immobility time was significantly shorter （P＜0.05）. The results of non-targeted metabolomics showed that a total of 78 endogenous differential metabolites were identified， with 40， 35 and 24 in the PFC， NAc and VTA regions respectively， mainly involved in amino acid， lipid and sphingolipid metabolism. The results of metabolic pathway enrichment analysis showed that SGHWT affected the neural circuits of depressed rats by regulating sphingolipid metabolism， alanine， aspartic acid and glutamic acid metabolism， saturated fatty acid biosynthesis， among which alanine， aspartic acid and glutamic acid metabolism was predominantly involved. Validation experiments showed that SGHWT significantly increased the phosphorylation levels of protein kinase B （Akt） and mammalian target of rapamycin （mTOR）， and decreased the protein expression of N-methyl-D-aspartic acid receptor 1 （NMDAR1） in the NAc region of rats. CONCLUSIONS SGHWT significantly improves the depression-like behavior and attenuates pathological damage of PFC-NAc-VTA neural circuit of model rats， the mechanism of which is associated with inhibiting NMDAR1 expression and activating the Akt/mTOR signaling pathway.

Animal experiments are widely used in biomedical research for safety assessment, toxicological analysis, efficacy evaluation, and mechanism exploration. In recent years, the ethical review system has become more stringent, and awareness of animal welfare has continuously increased. To promote more efficient and cost-effective drug research and development, the United States passed the Food and Drug Administration (FDA) Modernization Act 2.0 in September 2022, which removed the federal mandate requiring animal testing in preclinical drug research. In April 2025, the FDA further proposed to adopt a series of "new alternative methods" in the research and development of drugs such as monoclonal antibodies, which included artificial intelligence computing models, organoid toxicity tests, and 3D micro-physiological systems, thereby gradually phasing out traditional animal experiment models. Among these cutting-edge technologies, 3D bioprinting models are a significant alternative and complement to animal models, owing to their high biomimetic properties, reproducibility, and scalability. This review provides a comprehensive overview of advancements and applications of 3D bioprinting technology in the fields of biomedical and pharmaceutical research. It starts by detailing the essential elements of 3D bioprinting, including the selection and functional design of biomaterials, along with an explanation of the principles and characteristics of various printing strategies, highlighting the advantages in constructing complex multicellular spatial structures, regulating microenvironments, and guiding cell fate. It then discusses the typical applications of 3D bioprinting in drug research and development,including high-throughput screening of drug efficacy by constructing disease models such as tumors, infectious diseases, and rare diseases, as well as conducting drug toxicology research by building organ-specific models such as those of liver and heart. Additionally,the review examines the role of 3D bioprinting in tissue engineering, discussing its contributions to the construction of functional tissues such as bone, cartilage, skin, and blood vessels, as well as the latest progress in regeneration and replacement. Furthermore, this review analyzes the complementary advantages of 3D bioprinting models and animal models in the research of disease progression, drug mechanisms, precision medicine, drug development, and tissue regeneration, and discusses the potential and challenges of their integration in improving model accuracy and physiological relevance. In conclusion, as a cutting-edge in vitro modeling and manufacturing technology, 3D bioprinting is gradually establishing a comprehensive application system covering disease modeling, drug screening, toxicity prediction, and tissue regeneration.

Animal experiments are widely used in biomedical research for safety assessment, toxicological analysis, efficacy evaluation, and mechanism exploration. In recent years, the ethical review system has become more stringent, and awareness of animal welfare has continuously increased. To promote more efficient and cost-effective drug research and development, the United States passed the Food and Drug Administration (FDA) Modernization Act 2.0 in September 2022, which removed the federal mandate requiring animal testing in preclinical drug research. In April 2025, the FDA further proposed to adopt a series of "new alternative methods" in the research and development of drugs such as monoclonal antibodies, which included artificial intelligence computing models, organoid toxicity tests, and 3D micro-physiological systems, thereby gradually phasing out traditional animal experiment models. Among these cutting-edge technologies, 3D bioprinting models are a significant alternative and complement to animal models, owing to their high biomimetic properties, reproducibility, and scalability. This review provides a comprehensive overview of advancements and applications of 3D bioprinting technology in the fields of biomedical and pharmaceutical research. It starts by detailing the essential elements of 3D bioprinting, including the selection and functional design of biomaterials, along with an explanation of the principles and characteristics of various printing strategies, highlighting the advantages in constructing complex multicellular spatial structures, regulating microenvironments, and guiding cell fate. It then discusses the typical applications of 3D bioprinting in drug research and development,including high-throughput screening of drug efficacy by constructing disease models such as tumors, infectious diseases, and rare diseases, as well as conducting drug toxicology research by building organ-specific models such as those of liver and heart. Additionally,the review examines the role of 3D bioprinting in tissue engineering, discussing its contributions to the construction of functional tissues such as bone, cartilage, skin, and blood vessels, as well as the latest progress in regeneration and replacement. Furthermore, this review analyzes the complementary advantages of 3D bioprinting models and animal models in the research of disease progression, drug mechanisms, precision medicine, drug development, and tissue regeneration, and discusses the potential and challenges of their integration in improving model accuracy and physiological relevance. In conclusion, as a cutting-edge in vitro modeling and manufacturing technology, 3D bioprinting is gradually establishing a comprehensive application system covering disease modeling, drug screening, toxicity prediction, and tissue regeneration.

OBJECTIVE To investigate the improvement effects and mechanism of Zhichi suanzaoren decoction （ZSD） on hippocampal oxidative stress injury in hippocampal neurons of mice with perimenopausal insomnia. METHODS The potential targets of active ingredients in ZSD were predicted using TCMSP and TCMIP databases； the targets related to insomnia were searched through GeneCards， OMIM and DisGeNET databases； protein-protein interaction network of intersecting targets of ZSD ingredients and insomnia was constructed； Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were conducted on key targets. Sixty mice were divided into sham operation group， model group， ZSD low-， medium-， and high-dose groups （11， 22， and 33 g/kg）， and eszopiclone group （positive control， 1 mg/kg）. Except for sham operation group， the perimenopausal insomnia model was constructed by ovariectomy （OVX） in the other groups. After successful modeling， mice in each group were gavaged with normal saline or the corresponding drug solution， once a day， for three consecutive weeks. The sleep status of mice was evaluated through the pentobarbital sodium sleep synergy experiment， and the pathological changes of hippocampal neurons and the expressions of related genes and proteins in mice were observed by HE staining， immunohistochemistry staining， immunofluorescence staining， transcriptome sequencing technology and Western blot. RESULTS The results of network pharmacology showed that there were 296 intersection targets between ZSD and perimenopausal insomnia. Protein kinase B1 （Akt1） was a key target for treating insomnia with ZSD. After administration of ZSD， the sleep latency of mice was shortened， the sleep duration was prolonged significantly， and the mean optical density value of neuron-specific nuclear protein in the hippocampal CA1 region was significantly increased （P＜0.01）. Additionally， hippocampal neuron damage in OVX mice was significantly alleviated. The results of transcriptome sequencing showed that ZSD significantly upregulated the transcriptional levels of Nfe2l2 gene in hippocampal tissue of OVX mice （P＜0.05）. After administration of ZSD， protein expressions of nuclear factor E2 related factor 2 （Nrf2） and heme oxygenase-1 （HO-1） in hippocampal tissue of OVX mice， as well as the phosphorylated Akt level， were increased significantly （P＜0.01）. CONCLUSIONS ZSD can ameliorate hippocampal oxidative stress injury of hippocampal neurons in perimenopausal insomnia mice by activating the Akt/Nrf2/HO-1 signaling pathway.

OBJECTIVE To provide practical basis and policy recommendations for improving the pharmacovigilance （PV） system construction in medical institutions across China. METHODS A questionnaire survey was conducted using a mixed sampling strategy of “online random sampling+offline supplementary sampling” to distribute questionnaires among pharmaceutical professionals in tertiary medical institutions nationwide. The questionnaire covered aspects such as the construction of PV systems， job position settings， information system support， operational practices， and multi-stakeholder collaboration. The data were analyzed using descriptive methods and SPSS 20.0 statistical software. RESULTS A total of 70 valid questionnaires were collected from 66 medical institutions， primarily Class A tertiary hospitals. The survey found that 90.00% had designated PV personnel and 74.29% routinely conducted PV activities. However， there were notable disparities in resource allocation and information system capacity， with less than 50% of the institutions conducting post-marketing drug re-evaluation. PV activities were primarily focused on the collection and reporting of adverse drug reactions， with limited capabilities in signal detection and risk assessment. CONCLUSIONS Among the surveyed tertiary hospitals， PV systems have begun to take shape. However， challenges persist in terms of system establishment， resource allocation， risk assessment， and inter-organizational coordination. Policy efforts should focus on strengthening regulatory frameworks， improving information sharing mechanisms， enhancing professional training， and strengthening collaboration between hospitals and market authorization holders to ensure the effective implementation of PV in medical institutions.

BACKGROUND: Without timely and effective rehabilitation, hearing loss may profoundly affect human life quality. China has a large population of hearing-impaired individuals, which imposes a heavy health burden on society. Moreover, this population is projected to increase rapidly owing to China's aging society. METHODS: We used data from a population-representative epidemiological investigation of hearing loss and ear diseases in four Chinese provinces. We estimated the national prevalence using multiple linear regression of the age-group proportions and prevalence in 31 provinces with clustering analysis. We used years lived with disability (YLDs) to analyze the disease burden and forecasted the prevalence of hearing loss by 2060 in China. RESULTS: An estimated 115 million people had moderate-to-complete hearing loss in 2015 across the 31 provinces of China (8.4% of 1.37 billion people). Of these, 85.7% were older than age 50 years (99 million people) and 2.4% were younger than 20 years old (2.8 million people). Of all YLDs attributable to hearing loss, 68.9% were attributable to moderate-to-complete cases. By 2060, a projected 242 million people in China will have moderate-to-complete hearing loss, a 110.0% increase from 2015. CONCLUSIONS The hearing loss prevalence in China is high. Population aging and socioeconomic factors substantially affect the prevalence and severity of hearing loss and the disease burden. The prevalence and severity of hearing loss are unevenly distributed across different provinces. Future public health policies should take these trends and regional variations into account.
Humans ; China/epidemiology* ; Hearing Loss/epidemiology* ; Prevalence ; Middle Aged ; Male ; Female ; Adult ; Aged ; Adolescent ; Young Adult ; Child ; Child, Preschool ; Infant ; Aged, 80 and over ; Cost of Illness

Jiuwei Xifeng Granules have become a Chinese patent medicine in the market. Because the formula contains Os Draconis, a top-level protected fossil of ancient organisms, the formula was to be improved by replacing Os Draconis with Ostreae Concha. To evaluate whether the improved formula has the same effectiveness and safety as the original formula, a randomized, double-blind, parallel-controlled, equivalence clinical trial was conducted. This study enrolled 288 tic disorder(TD) of children and assigned them into two groups in 1∶1. The treatment group and control group took the modified formula and original formula, respectively. The treatment lasted for 6 weeks, and follow-up visits were conducted at weeks 2, 4, and 6. The primary efficacy endpoint was the difference in Yale global tic severity scale(YGTSS)-total tic severity(TTS) score from baseline after 6 weeks of treatment. The results showed that after 6 weeks of treatment, the declines in YGTSS-TSS score showed no statistically significant difference between the two groups. The difference in YGTSS-TSS score(treatment group-control group) and the 95%CI of the full analysis set(FAS) were-0.17[-1.42, 1.08] and those of per-protocol set(PPS) were 0.29[-0.97, 1.56], which were within the equivalence boundary [-3, 3]. The equivalence test was therefore concluded. The two groups showed no significant differences in the secondary efficacy endpoints of effective rate for TD, total score and factor scores of YGTSS, clinical global impressions-severity(CGI-S) score, traditional Chinese medicine(TCM) response rate, or symptom disappearance rate, and thus a complete evidence chain with the primary outcome was formed. A total of 6 adverse reactions were reported, including 4(2.82%) cases in the treatment group and 2(1.41%) cases in the control group, which showed no statistically significant difference between the two groups. No serious suspected unexpected adverse reactions were reported, and no laboratory test results indicated serious clinically significant abnormalities. The results support the replacement of Os Draconis by Ostreae Concha in the original formula, and the efficacy and safety of the modified formula are consistent with those of the original formula.
Adolescent ; Child ; Child, Preschool ; Female ; Humans ; Male ; Double-Blind Method ; Drugs, Chinese Herbal/therapeutic use* ; Tic Disorders/drug therapy* ; Treatment Outcome