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 by which Feixin decoction treats hypoxic pulmonary hypertension （HPH） by regulating the peroxisome proliferator-activated receptor gamma （PPARγ）/nuclear factor-kappa B （NF-κB）/NOD-like receptor pyrin domain containing 3 （NLRP3） signaling pathway. MethodsForty-eight male SD rats were randomly allocated into normal， hypoxia， and low-， medium- and high-dose （5.85， 11.7， 23.4 g·kg^-1， respectively） Feixin decoction groups， with 8 rats in each group. Except the normal group， the remaining five groups were placed in a hypoxia chamber with an oxygen concentration of （10.0±0.5）% for 8 h per day， 28 days， and administrated with corresponding drugs during the modeling process. After 4 weeks of treatment， echocardiographic parameters ［pulmonary artery acceleration time （PAT）， pulmonary artery ejection time （PET）， right ventricular anterior wall thickness （RVAWd）， and tricuspid annular plane systolic excursion （TAPSE）］ were measured for each group. The right ventricular systolic pressure （RVSP） was measured by the right heart catheterization method， and the right ventricular hypertrophy index （RVHI） was calculated by weighing the heart. The pathological changes in pulmonary arterioles were observed by hematoxylin-eosin staining. The co-localization of α-smooth muscle actin （α-SMA） with NLRP3， N-terminal gasdermin D （N-GSDMD）， and cysteinyl aspartate-specific proteinase-1 （Caspase-1） in pulmonary arteries was detected by immunofluorescence. The protein levels of PPARγ， NF-κB， NLRP3， apoptosis-associated speck-like protein containing a CARD （ASC）， N-GSDMD， interleukin-1β （IL-1β）， interleukin-18（IL-18）， and cleaved Caspase-1 in the lung tissue was determined by Western blot. The ultrastructural changes in pulmonary artery smooth muscle cells （PASMCs） were observed by transmission electron microscopy. ResultsCompared with the normal group， the hypoxia group showed increased RVSP and RVHI （P<0.01）， decreased right heart function （P<0.01）， increased pulmonary vascular remodeling （P<0.01）， increased co-localization of α-SMA with NLRP3， N-GSDMD， and Caspase-1 in pulmonary arterioles （P<0.01）， up-regulated protein levels of NF-κB， NLRP3， ASC， N-GSDMD， IL-1β， IL-18， and cleaved Caspase-1 in the lung tissue （P<0.05， P<0.01）， a down-regulated protein level of PPARγ （P<0.05， P<0.01）， and pyroptosis in PASMCs. Compared with the hypoxia group， Feixin decoction reduced RVSP and RVHI， improved the right heart function and ameliorated pulmonary vascular remodeling （P<0.05， P<0.01）， decreased the co-localization of α-SMA with NLRP3， N-GSDMD， and Caspase-1 （P<0.05， P<0.01）， down-regulated the protein levels of NF-κB， NLRP3， ASC， N-GSDMD， IL-1β， IL-18， and cleaved Caspase-1 in the lung tissue （P<0.05， P<0.01）， up-regulated the protein level of PPARγ （P<0.05， P<0.01）， and alleviated pyroptosis in PASMCs. ConclusionFeixin decoction can ameliorate pulmonary vascular remodeling and right heart dysfunction in chronically induced HPH rats by regulating pyroptosis in PASMCs through the PPARγ/NF-κB/NLRP3 pathway.

Objective We aimed to compared matrix metalloproteinase-13 (MMP-13) and transforming growth factor-β1 (TGF-β1) in synovial fluid,the phosphorylation level of Smad3 in articular cartilage (P-Smad3),and their correlation with traditional Chinese medicine (TCM) patterns in patients with knee osteoarthritis (KOA) of liver-kidney deficiency pattern and pattern of intermingled phlegm and blood stasis.Methods Using a cross-sectional field investigation method,KOA patients hospitalized in the Orthopedics Department of Dongzhimen Hospital,Beijing University of Chinese Medicine from September 2019 to February 2023 were collected. A total of 112 KOA patients were included,among which 63 cases were diagnosed with liver-kidney deficiency pattern,and 49 cases were diagnosed with pattern of intermingled phlegm and blood stasis. The intensity of knee pain,function,and X-ray imaging result were quantified using the Visual Analogue Scale (VAS),Lysholm Knee Scoring Scale,and Kellgren-Lawrence (K-L) Grading Scale,respectively. The TCM pattern was identified and quantified using a TCM Pattern Scoring Scale. Immunohistochemistry was used to determine the phosphorylation characteristics of Smad3 in articular cartilage,and ELISA was used to measure the contents of MMP-13 and TGF-β1 in synovial fluid. The level characteristics and their correlation with the degree of syndrome were analyzed.Results (i) There was no statistically significant difference in VAS scores,Lysholm scores,and K-L grades between KOA patients with different TCM patterns. (ii) Compared with KOA patients with pattern of intermingled phlegm and blood stasis,patients with pattern of liver-kidney deficiency had higher levels of MMP-13 in synovial fluid and lower levels of TGF-β1 in synovial fluid (P<0.05). (iii) In KOA patients with liver-kidney deficiency pattern,there was a positive correlation between the level of MMP-13 in synovial fluid and the score of TCM pattern (r=0.292,P=0.020),while there was a negative correlation between the level of TGF-β1 in synovial fluid and the score of TCM pattern (r=-0.781,P<0.001). In KOA patients with pattern of intermingled phlegm and blood stasis,there was also a positive correlation between the level of MMP-13 in synovial fluid and the score of TCM pattern (r=0.936,P<0.001). (iv) The mean optical density value of P-Smad3 in articular cartilage was lower in KOA patients with liver-kidney deficiency pattern than in pattern of intermingled phlegm and blood stasis (P<0.05).Conclusion KOA patients with liver-kidney deficiency pattern or pattern of intermingled phlegm and blood stasis have different levels of TGF-β1 and MMP-13 in synovial fluid,as well as varying degrees of Smad3 phosphorylation in articular cartilage,which is consistent with the analysis of etiology and pathogenesis under different patterns. The levels of TGF-β1 and MMP-13 in synovial fluid of patients with liver-kidney deficiency pattern can reflect the severity of the pattern to a certain extent,and the mechanism may be related to the inhibition of the activation level of the TGF-β/Smad signaling pathway. This study enriches the research content of the material basis of TCM patterns.

BACKGROUND:The lower cervical vertebral pedicle is the main stress site of the posterior column of the spine,which is of great significance for the maintenance of the stability of the human center of gravity and the reduction of shock.At present,there are few reports on the characteristics of the internal bone trabeculae,and the characteristics of the joint site of the vertebral pedicle with the articular process and the vertebral body.It is urgent to understand the fine anatomical structure of the vertebral pedicle and the relationship and function of each part. OBJECTIVE:To observe the microanatomical morphology of the vertebral pedicle by Micro-CT scanning of cervical vertebra specimens,and to measure and analyze the microstructure and morphometric parameters of the bone trabecula in the cervical pedicle under normal conditions to evaluate the safety performance of the cervical spine. METHODS:Micro-CT scanning was performed on 31 sets of cervical vertebrae C3-C7.By checking and reconstructing the areas of interest in the bone trabecular within the vertebral pedicle,the morphological characteristics and distribution direction of the bone trabecular within the cervical pedicle were observed,and the bone microstructure parameters were detected,and the differences in the bone microstructure of the C3-C7 vertebral pedicle were analyzed and compared. RESULTS AND CONCLUSION:(1)The Micro-CT images showed that the honeycomb bone trabeculae of the pedicle of the lower cervical spine presented a complex network of microstructures.The trabeculae near the cortical bone were lamellar and relatively compact,extending forward toward the vertebral body and backward toward the articular process lamina.Abatoid bone trabeculae extended into the medullary cavity and transformed into a network structure,and then into rod-shaped bone trabeculae.The rod-shaped bone trabeculae were sparsely distributed in the medullary cavity.(2)Statistical results of morphological parameters of bone trabeculae showed that bone volume fraction values in C4 and C5 were higher than that in C7(P＜0.05).The bone surface/bone volume value in C7 was higher than that in C3,C4 and C6(P＜0.05).The bone surface density of bone trabeculae in C7 was higher than that in C3,C4,C5 and C6(P＜0.05).Trabecular thickness in C7 was higher than that in C3,C4 and C5(P＜0.05).Bone surface/bone volume and bone surface density of the left pedicle bone trabecular were greater than those on the right side(P＜0.05).(3)The microstructural changes of C3-C7 were summarized,in which the load capacity and stress of the C7 pedicle were poor,and the risk of injury was high in this area.

Objective To investigate the value of 18F labeled prostate-specific membrane antigen(18F-PSMA)-1007 developing agent PET/CT(18F-PSMA-1007PET/CT)examination in the diagnostic evaluation and therapeutic decision of the newly diagnosed prostate cancer(PCa)and follow up after radical prostatecto-my(RP).Methods This study adopted the retrospective observational study method.A total of 68 patients receiving 18 F-PSMA-1007 PET/CT examination in this hospital from September 2022 to October 2023 were analyzed,including 36 cases of newly diagnosed PCa and 32 cases of biochemistry follow up failure after RP.A total of 30 items of clinical data were collected,including 8 items of basic clinical characteristics,7 items of pa-thology-related characteristics and 15 items of imaging characteristics.The patients clinical characteristics in the newly diagnosed PCa and biochemical failure after RP conducted the descriptive analysis.The Fisher exact probability method was used to analyze the differentiation of the SUVmax of primary lesions in different clini-cal subgroups[different tPSA levels at diagnosis,different mi-T stages,different Gleason scores at postopera-tive pathological puncture and different pathological types]in the newly diagnosed PCa group and the differ-entiation of recurrent lesion detection rates in different clinical subgroups(different tPSA in 18F-PSMA-1007 PET/CT examination,different pathological T stages,different lymph node invasion and different pathological Gleason scores in the biochemical failure after RP group.The Spearman correlation was adopted to test and analyze the correlation between the imaging features of positive lesions and tPSA.Results In the newly diag-nosed PCa group,there were 1 case of prostatic hyperplasia and 35 cases of PCa.SUVmax had no statistical differences among the primary lesions with different tPSA levels(P=0.81),different mi-T stages(P=0.70),different puncture Glleasonscores(P=0.20)and different pathological types(P=0.71).Moreover the tPSA value at diagnosis was positively correlated with the number of metastatic lesions(r=0.410,P=0.01).The clinical treatment decisions in 11 cases(31.43％)were changed according to the examination re-sults.In 9 cases of RP combined with lymph node dissection,the accuracy rate and concordance rate of 18F-PS-MA-1007 PET/CT and MRI in the lymph node detection rate all were 100％.I n the biochemical failure after RP group,the overall recurrent lesion detection rate was 71.88％(23/32),the operative area in situ recurrence(11 cases,34.38％)and bone metastasis(11 cases,34.38％)were most common.The differences of 18F-PS-MA-1007 PET/CT recurrent lesions detection rates had no statistical differences among the patients with dif-ferent tPSA levels(P=0.08),different pathological T stages(P=0.10),different postoperative pathological lymph node invasions(P=0.68)and different pathologic Gleason score in the 18F-PSMA-1007 PET/CT ex-amination.In the 18 F-PSMA-1007 PET/CT examination in the biochemical failure after RP,the tPSA value in the recurrent lesion was positively correlated with the number of recurrent lesions(r=0.48,P=0.01),SUVmax value in the recurrent lesion(r=0.46,P=0.01)and the SUVmean value(r=0.38,P=0.03).The clinical treatment decision in 18 cases(56.25％)was changed according to the examination results.Conclusion 18 F-PSMA-1007 PET/CT has good diagnostic value and efficiency for primary lesion and metastasis lesion of new-ly diagnosed PCa and recurrent foci of biochemical failure after RP.

177Lu-prostate specific membrane antigen(PSMA)radio-ligand therapy has been approved abroad for advanced prostate cancer and has been in several clinical trials in China.Based on domestic clinical practice and experimental data and referred to international experience and viewpoints,the expert group forms a consensus on the clinical application of 177Lu-PSMA radio-ligand therapy in prostate cancer to guide clinical practice.

Objective To develop an intelligent model for differential diagnosis of atrioventricular nodal re-entrant tachycardia(AVNRT)and atrioventricular re-entrant tachycardia(AVRT)using 12-lead wearable electrocardiogram devices.Methods A total of 356 samples of 12-lead supraventricular tachycardia(SVT)electrocardiograms recorded by wearable devices were randomly divided into training and validation sets using 5-fold cross validation to establish the intelligent classification model,and 101 patients with the diagnosis of SVT undergoing electrophysiological studies and radiofrequency ablation from October,2021 to March,2023 were selected as the testing set.The changes in electrocardiogram parameters before and during induced tachycardia were compared.Based on multiscale deep neural network,an intelligent diagnosis model for classifying SVT mechanisms was constructed and validated.The 3-lead electrocardiogram signals from Ⅱ,Ⅲ,and V1 were extracted to build new classification models,whose diagnostic efficacy was compared with that of the 12-lead model.Results Of the 101 patients with SVT in the testing set,68 were diagnosed with AVNRT and 33 were diagnosed with AVRT by electrophysiological study.The pre-trained model achieved a high area under the precision-recall curve(0.9492)and F1 score(0.8195)for identifying AVNRT in the validation set.The total F1 scores of the lead Ⅱ,Ⅲ,V1,3-lead and 12-lead intelligent diagnostic models in the testing set were 0.5597,0.6061,0.3419,0.6003 and 0.6136,respectively.Compared with the 12-lead classification model,the lead-Ⅲ model had a net reclassification index improvement of-0.029(P=0.878)and an integrated discrimination index improvement of-0.005(P=0.965).Conclusion The intelligent diagnostic model based on multiscale deep neural network using wearable electrocardiogram devices has an acceptable accuracy for classifying SVT mechanisms.

Objective To develop an intelligent model for differential diagnosis of atrioventricular nodal re-entrant tachycardia(AVNRT)and atrioventricular re-entrant tachycardia(AVRT)using 12-lead wearable electrocardiogram devices.Methods A total of 356 samples of 12-lead supraventricular tachycardia(SVT)electrocardiograms recorded by wearable devices were randomly divided into training and validation sets using 5-fold cross validation to establish the intelligent classification model,and 101 patients with the diagnosis of SVT undergoing electrophysiological studies and radiofrequency ablation from October,2021 to March,2023 were selected as the testing set.The changes in electrocardiogram parameters before and during induced tachycardia were compared.Based on multiscale deep neural network,an intelligent diagnosis model for classifying SVT mechanisms was constructed and validated.The 3-lead electrocardiogram signals from Ⅱ,Ⅲ,and V1 were extracted to build new classification models,whose diagnostic efficacy was compared with that of the 12-lead model.Results Of the 101 patients with SVT in the testing set,68 were diagnosed with AVNRT and 33 were diagnosed with AVRT by electrophysiological study.The pre-trained model achieved a high area under the precision-recall curve(0.9492)and F1 score(0.8195)for identifying AVNRT in the validation set.The total F1 scores of the lead Ⅱ,Ⅲ,V1,3-lead and 12-lead intelligent diagnostic models in the testing set were 0.5597,0.6061,0.3419,0.6003 and 0.6136,respectively.Compared with the 12-lead classification model,the lead-Ⅲ model had a net reclassification index improvement of-0.029(P=0.878)and an integrated discrimination index improvement of-0.005(P=0.965).Conclusion The intelligent diagnostic model based on multiscale deep neural network using wearable electrocardiogram devices has an acceptable accuracy for classifying SVT mechanisms.

Objective:To investigate the sensitivity of tumor organoids derived from samples of colorectal cancer to lobaplatin and oxaliplatin hyperthermic perfusion in vitro and to assist clinical development of hyperthermic intraperitoneal chemotherapy. Method:Tumor samples and relevant clinical data were collected from patients with pathologically confirmed colorectal cancer in the Sixth Affiliated Hospital of Sun Yat-sen University from July 2021 to December 2022. Organoids were cultured and tumor tissue were passaged. In vitro hyperthermic perfusion experiments were performed on organoids with good viability. Firstly, 10 organoids were treated with oxaliplatin and lobaplatin at the following six concentrations: 1 000, 250, 62.5, 15.6, 3.9, and 0.98 μmol/L. The organoids were exposed to oxaliplatin at 42℃ for 30 minutes and to lobaplatin at 42℃ for 60 minutes. Dose-response curves of responses to in vitro hyperthermic perfusion with these two drugs were constructed and evaluated. Clinical doses of oxaliplatin and lobaplatin were further tested on 30 organoids. This testing revealed oxaliplatin was effective at 579 μmol/L at a hyperthermic perfusion temperature of 42℃ for 30 min and lobaplatin was effective at 240 μmol/L at a hyperthermic perfusion temperature of 42℃ for 60 minutes. Result:Thirty-two tumor organoids were cultured from samples of colorectal cancer. The median concentration required for oxaliplatin to eliminate 50% of tumor cells (IC50) was 577.45 μmol/L (IQR: 1846.09 μmol/L). The median IC50 for lobaplatin was 85.04 μmol/L (IQR: 305.01 μmol/L).The difference between the two groups was not statistically significant ( Z=1.784, P=0.084). In seven of 10 organoids, lobaplatin showed a greater IC50 after in vitro hyperthermic perfusion than did oxaliplatin. Testing of 30 organoids with clinical doses of oxaliplatin and lobaplatin revealed that oxaliplatin achieved an average inhibition rate of 39.6% (95%CI: 32.1%?47.0%), whereas the average rate of inhibition for lobaplatin was 89.7% (95%CI: 87.0%?92.3%): this difference is statistically significant ( t=?15.282, P<0.001). Conclusion:The rate of inhibition achieved by hyperthermic perfusion of lobaplatin in vitro is better than that achieved by hyperthermic perfusion with oxaliplatin. Lobaplatin is more effective than oxaliplatin when administered by hyperthermic intraperitoneal perfusion and therefore has the potential to replace oxaliplatin in this setting.

Objective:To investigate the sensitivity of tumor organoids derived from samples of colorectal cancer to lobaplatin and oxaliplatin hyperthermic perfusion in vitro and to assist clinical development of hyperthermic intraperitoneal chemotherapy. Method:Tumor samples and relevant clinical data were collected from patients with pathologically confirmed colorectal cancer in the Sixth Affiliated Hospital of Sun Yat-sen University from July 2021 to December 2022. Organoids were cultured and tumor tissue were passaged. In vitro hyperthermic perfusion experiments were performed on organoids with good viability. Firstly, 10 organoids were treated with oxaliplatin and lobaplatin at the following six concentrations: 1 000, 250, 62.5, 15.6, 3.9, and 0.98 μmol/L. The organoids were exposed to oxaliplatin at 42℃ for 30 minutes and to lobaplatin at 42℃ for 60 minutes. Dose-response curves of responses to in vitro hyperthermic perfusion with these two drugs were constructed and evaluated. Clinical doses of oxaliplatin and lobaplatin were further tested on 30 organoids. This testing revealed oxaliplatin was effective at 579 μmol/L at a hyperthermic perfusion temperature of 42℃ for 30 min and lobaplatin was effective at 240 μmol/L at a hyperthermic perfusion temperature of 42℃ for 60 minutes. Result:Thirty-two tumor organoids were cultured from samples of colorectal cancer. The median concentration required for oxaliplatin to eliminate 50% of tumor cells (IC50) was 577.45 μmol/L (IQR: 1846.09 μmol/L). The median IC50 for lobaplatin was 85.04 μmol/L (IQR: 305.01 μmol/L).The difference between the two groups was not statistically significant ( Z=1.784, P=0.084). In seven of 10 organoids, lobaplatin showed a greater IC50 after in vitro hyperthermic perfusion than did oxaliplatin. Testing of 30 organoids with clinical doses of oxaliplatin and lobaplatin revealed that oxaliplatin achieved an average inhibition rate of 39.6% (95%CI: 32.1%?47.0%), whereas the average rate of inhibition for lobaplatin was 89.7% (95%CI: 87.0%?92.3%): this difference is statistically significant ( t=?15.282, P<0.001). Conclusion:The rate of inhibition achieved by hyperthermic perfusion of lobaplatin in vitro is better than that achieved by hyperthermic perfusion with oxaliplatin. Lobaplatin is more effective than oxaliplatin when administered by hyperthermic intraperitoneal perfusion and therefore has the potential to replace oxaliplatin in this setting.