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Objective To explore the effect of multi-dimensional reduction in the treatment of keloid in high-tension areas, using layered fishbone-type reduction suture, combined with superficial X-ray radiotherapy as postoperative treatment. Methods From July 2020 to January 2023, a total of 110 cases (162 lesions) were selected from the outpatient department and inpatient department of Dermatology of Sichuan People's Hospital, who were treated with fishbone layered tensioning suture, combined with superficial X-ray radiotherapy after surgery and were able to follow up. According to the location, number and tension of keloids, the scar tissue was removed by single or partial resection. In the operation, the improved multi-layer reduction suture was used to form the fishbone type, and the skin was tension-free and mildly eversion, superficial X-ray radiotherapy was started 24-72 hours after operation, four times, the total dose was 20 Gy; the skin tension was reduced by 3-6 months using a needle-free suture device, and the silicone preparation was externally applied for three months. Follow-up observations were 8-24 months. Patients with postoperative recurrence were treated with dye laser and (or) intra-cicatricial drug injection according to the situation, and shallow X-ray radiotherapy was added twice if necessary. Results In 110 cases (162 lesions), keloid was clinically cured in 103 cases (151 lesions), no obvious signs of recurrence were found, and the average scar stretching was less than 5 mm. Signs of recurrence occurred in seven cases (11 lesions), which were improved after superficial X-ray therapy, dye laser therapy, and local injection of fluorouracil and glucocorticoid. Conclusion Keloid in the high tension area is still difficult in treatment. The method of layered fishbone suture combined with multi-dimensional tension reduction in the surgical treatment can reduce the postoperative incision tension in the high tension area, which is worthy of popularization and application in clinic. [ABSTRACT FROM AUTHOR]

To reduce the risk of surgical site infections, and then make silk sutures have antibacterial properties, the natural antibacterial agent curcumin (Cur) was encapsulated into zeolitic imidazolate framework-8 (ZIF-8) by solvent synthesis method to prepare drug-loaded nanoparticles ZIF-8@Cur. A series of antibacterial silk sutures were prepared by adjusting the mass concentration of ZIF-8@Cur by loading ZIF-8@Cur onto the silk sutures with dip coating method. The influence law of ZIF-8@Cur mass concentration on the chemical structure, surface morphology, mechanical properties and drug loading of silk sutures was investigated by systematic physical and chemical characterization, and the optimal ZIF-8@Cur coating mass concentration was selected. The antibacterial properties and cytocompatibility of silk sutures were analyzed by antibacterial and cell experiments. The research indicates that ZIF-8@Cur is successfully synthesized and loaded onto the sutures surface. When the mass concentration of ZIF-8@Cur is 15 mg/mL, the nanoparticle coating on the surface of S/ZC15 is uniform and smooth, and the drug loading of S/ZC15 is 15.45 μg. The sutures still maintain excellent mechanical properties after coating, which meet the strength requirements of medical sutures. In addition, S/ZC15 has good antibacterial properties and cytocompatibility, which is expected to inhibit the occurrence of surgical site infections [ABSTRACT FROM AUTHOR]

To investigate the efficacy and safety of preserving fallopian tube function under laparoscopy,and its effect on long-term reproductive function.Methods A total of 100 patients with tubal pregnancy admitted to a hospital from May 2018 to May 2019 were selected and randomly divided into the study group and control group.There were 50 patients in each group.In the study group,the embryo was removed by linear tubal incision and the mesosalpinx margin was sutured to restore the anatomical structure of the fallopian tubes.In the control group,the oviduct was linearly cut and embryos were removed,the bleeding was stopped by electrocoagulation,and the oviduct was not sutured.The operative time,intraoperative bleeding, serum β-human chorionic gonadotropin (HCG) value before surgery,1,3 and 7 days after surgery,length of hospital stay,recovery of anal ventilation after surgery,catheter removal time,degree of fallopian tube patency and recurrence rate of natural pregnancy were compared between the two groups.Results Compared with those of the control group,the operative time was longer,and the degree of fallopian tube patency and the rate of second natural pregnancy were significantly better in the study group (P <0.05).However,there were no significant differences in intraoperative bleeding,postoperative anal ventilation,postoperative HCG decline, length of hospital stays and postoperative catheter extraction time between the two groups (P >0.05).Conclusion Laparoscopic preservation of fallopian tube function is safe and effective in patients with tubal pregnancy, which is helpful to preserve the fertility of patients. [ABSTRACT FROM AUTHOR]

Objective Using bioinformatics methods to find genes that are differentially expressed in the dura mater at the skull suture of the young and adult sheep, and to analyze the genes that affect the growth of the skull and their corresponding signal pathways. Methods We took the dura mater of the apical frontal suture and sagittal suture for genetic sequencing from six 51-day-old young sheep and six 12-month-old adult sheep. With adult sheep as the control group and young sheep as the experimental group, the results were analyzed for the differential expression, and the differentially expressed genes were analyzed for GO enrichment. Then, the up-regulated and down-regulated genes that affected the growth of the skull were enriched by the KEGG signaling pathway. Frozen young sheep and adult sheep dura mater tissues were taken, and the top 10 genes with the highest differential expression were verified by fluorescence quantitative PCR. Results Compared with the adult sheep, there were 765 differentially expressed genes in the dural tissues of young sheep, including 417 up-regulated genes and 348 down-regulated genes. Bone mineralization was seen after the enrichment of differentially expressed genes in the dural tissues of young sheep and adult sheep, and the positive regulation of bone mineralization was seen after the enrichment of differentially expressed genes. among the up-regulated genes, bone mineralization included 15 genes, namely ENPPl, HlFlA, IBSP, MMP13, PI'N, OMD, COL1A2, BGLAP, FBN2, ASPN, TMEM119, RFLNB, PHOSPHOl, LOX, and ISG15; among the down-regulated genes, the positive regulation of hone mineralization included 5 genes, namely ISG15, OSRl, BMP4, BMP6, and BMP7. KEGG signaling pathway analysis showed that bone mineralization related genes mainly involved P13K-Akt signaling pathway, and positive regulation of bone mineralization genes mainly involved TGF-~ signaling pathway. Among the up-regulated genes, the first 6 genes with the most up-regulation were COL1A2, MMP13, PHOSPHOl, IBSP, OMD, and PI'N, and the top 2 genes with the most down-regulation were BMP4 and BMP6, which were then selected for fluorescence quantitative PCR detection. The results showed that the difference in the above mentioned differentially expressed genes in the same suture between the young sheep and adult sheep was statistically significant ( P < 0. 05) . Conclusion Bioinformatics analysis showed that there are a large number of differentially expressed genes in the dura mater tissues at the suture of the young and adult sheep, which are involved in the hone mineralization and bone mineralization regulation; bone mineralization genes may promote the growth of the skull through the Pl3K-Akt signaling pathway, and hone morphogenetic protein genes may regulate the closure of sutures through the TGF-~ signaling pathway. [ABSTRACT FROM AUTHOR]

BACKGROUND: Maxillary transverse deficiency is a common malocclusion deformity encountered in clinical practice. Rapid maxillary expansion assisted with implant anchorage provides a new possibility for maxillary expansion in adults. OBJECTIVE: To review the research progress in the mechanism of maxillary expansion, providing ideas for bone remodeling between palatal sutures, obtaining the expansion volume and stability that meet the clinical needs. METHODS: We searched for relevant articles published from January 2010 to September 2020 in WanFang, CNKI, PubMed, and Web of Science with the keywords of “maxillary expansion, craniofacial suture, suture growth, mechanical force, bone remodeling, immunity cells, mesenchymal stem cells, craniosynostosis” in Chinese and English respectively. Finally, 69 articles met the criteria for review. RESULTS AND CONCLUSION: Maxillary expansion exerts mechanical force on the palatal suture by different clinical means to expand bone sutures and widen the constricted maxillary. This process not only requires the participation of osteoblasts and osteoclasts, but also involves the proliferation, differentiation and regulation of mesenchymal stem cells as well as immune cells. Under the action of mechanical force, a variety of cells interact with each other via cytokines, to complete bone remodeling through different signaling pathways. Referring to advances in the treatment of craniosynostosis, it provides a new idea for maxillary expansion by inhibiting the closure of bone suture at the end of growth and development, or reopening the fused suture. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Absorbable collagen suture has been reported to improve the healing effect for patients with type I and II surgical incisions. However, these studies are single-center small-sample trials, and the results are not clear. This study investigated the efficacy of absorbable collagen suture for type I and II surgical incisions. METHODS: Databases of PubMed, Web of Science, Cochrane Library, CNKI, Wanfang,and VIP were searched to retrieve the randomized controlled trials concerning the effects of absorbable collagen suture. The modified Jadad scale was used to evaluate the quality of the included research literature. The main outcome indicators were wound healing grades, wound leveling, and wound healing time. The secondary indicators were wound pain, incisional red swelling, and wound bleeding. Meta-analysis was conducted using Stata 16.0 software. RESULTS: (1) Eleven articles were included, and the median Jadad score was 3.0. There were 1 720 patients, including 887 patients in the trial group and 833 patients in the control group. (2) Meta-analysis results revealed that compared with the control group, in the trial group, incision healing level was improved (RR=1.44, 95%CI:1.02-1.86, P=0.00), and incision flatness was improved (RR=1.11, 95%CI:0.70-1.52, P=0.002); incision healing time was significantly reduced (WMD=-7.44, 95%CI:-8.09 to -6.79, P=0.00); incision pain was significantly reduced (RR=1.95, 95%CI:1.44-2.46, P=0.00); incision bleeding was significantly reduced (RR=-2.63, 95%CI:-4.65 to -0.61, P=0.01); incisional swelling was significantly reduced (RR=-1.00, 95%CI:-1.78 to-0.22, P=0.01). CONCLUSION: The efficacy of absorbable collagen thread for type I and II surgical incisions was better than that of the silk thread and ordinary absorbable suture. [ABSTRACT FROM AUTHOR]

Objective To investigate the therapeutic effect and analyze the influencing factors of toe amputation combined with skin edge suture in patients with diabetic toe gangrene at Wagner stage 3 to 4. Methods The clinical data of 45 patients with diabetic toe gangrene underwent toe amputation combined with skin edge suture in Department of Endocrinology of Air Force Medical Center from January 2016 to June 2019 were retrospectively analyzed. The patients were divided into grade A healing group and non-grade A healing group according to the postoperative wound healing. The clinical data of the two groups were compared by t test, nonparametric test and chi square test. According to whether antibiotics were applied after surgery and the course of antibiotic application, they were divided into the group without antibiotics, the group with 7 days of antibiotics and the group with 14 days of antibiotics, then wound grade A healing rates between groups were compared. According to the postoperative suture, the patients were divided into a primary suture group and a delayed suture group, and the wound grade A healing rates of both groups were compared. Kaplan-Meier survival curve analysis was used for the wound healing rate over time between primary and delayed suture groups. Results Forty-five patients were included in the study. The time from suture to wound healing was 14 (14, 20) days. Among them, there were 33 (73.3%) patients of grade A healing, 11 (24.4%) patients of grade B or C healing, and 1 patient (2.2%) underwent higher level amputation. The proportion of toe branchial index (TBI) ≥0.7 in grade A healing group was higher than that in non-grade A healing group [60.6% (20/33) vs. 16.7% (2/12), χ² =5.155, P=0.023]. The proportion of postoperative antibiotics use in grade A healing group was higher than that in non-grade A healing group [84.8% (28/33) vs. 25% (3/12), χ² =12.047, P=0.001]. There were 14 cases in the group without antibiotics, 5 cases with grade A healing; 17 cases in the group with antibiotics for 1 week, 16 cases with grade A healing; 14 cases in the group with antibiotics for 2 weeks, 12 cases with grade A healing. There was no significant difference in wound healing rate between the patients who used postoperative antibiotics for 7 days and 14 days (P=0.859). There were 37 cases in primary suture group, with grade A healing rate of 78.4% (29/37), and 8 cases in delayed suture group, 4 cases with grade A healing rate.The postoperative wound healing time of primary suture group was shorter than that of delayed suture group [14.00 (14.00, 14.00) days vs. 19.50 (18.25, 28.75) days, Z=-3.591, P=0.001]. Conclusion Under the effective control of soft tissue infection, toe amputation combined with primary suture and short-term anti-infective therapy is an effective treatment for patients with diabetic toe gangrene when TBI≥0.7. [ABSTRACT FROM AUTHOR]

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BACKGROUND: α-n-Butyl cyanoacrylate medical adhesive (504 medical adhesive) has good biocompatibility and anti-bacterial properties. It is a simple and effective medical adhesive. Little is reported on the application of α-n-butyl cyanoacrylate medical adhesive in surgical incision closure in the field of oral cavity. OBJECTIVE: To investigate the effect of α-n-butyl cyanoacrylate medical adhesive on oral mucosal wounds healing. METHODS: Fifteen female SD rat (Laboratory Animal Center of Chongqing Medical University, China) models of oral mucosal incisions were established and then divided into a natural healing group (without any treatment), silk suture group (interrupted stitches with absorbable surgical suture), and 504 medical adhesive group (wound closure with α-n-butyl cyanoacrylate medical adhesive) group. At 7 days after surgery, gross and histological observation was performed. Twenty female SD rats were established into models of 1 cm x 1 cm oral mucosa defect and then divided into two groups: a natural healing group (without any treatment) and a 504 closure group (covering the wound defect with α-n-butyl cyanoacrylate medical adhesive). At 10 days after surgery, gross and histological observation of defect area was performed. This study was approved by the Animal Ethics Committee of Chongqing Medical University, China. RESULTS AND CONCLUSION: Oral mucosal incision wound model: gross observation showed that the wounds in the three groups healed well, and no inflammatory reaction such as swelling and pus was found. Histological observation showed that the epithelium of the silk suture group was complete and continuous, the nail process of the epithelium was short and flat, the number of fibroblasts in the lamina propria increased, and a large number of inflammatory cells infiltrated in the suture track area. In the natural healing and 504 closure groups, the mucosal epithelium healed well, the nail process of the epithelium was thin and long, the fibroblasts in the lamina propria proliferated actively, and there were many collagen fibers. The fibers in the 504 closure group were arranged more closely and orderly than those in the silk suture group. Oral mucosa defect model: Gross observation showed that the wound in the natural healing group did not heal completely, and there was no infection such as swelling, necrosis, and ulceration. In the 504 closure group, wound surface basically healed. Histological observation revealed that in the natural healing group, mucosal defect was obvious, the epithelial layer was not closely connected with the lamina propria, necrotic tissue, a small amount of fibroblasts and a large number of inflammatory cells were observed. In the 504 closure group, the length of margin of mucosal defect was significantly reduced, fibroblast proliferation and vascular regeneration could be observed in the lamina propria, and fibers were orderly arranged. These results suggest that α-n-butyl cyanoacrylate medical adhesive has little foreign body reaction and can promote the regeneration of mucosal tissue, providing a potential method to close oral mucosal wound. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effectiveness of arthroscopic multi-point fixation with anchor and suture in the treatment of tibial insertion avulsion fracture of anterior cruciate ligament (ACL) involving the anterior root of lateral meniscus (LM)., Methods: A retrospective analysis was conducted on the clinical data of 28 patients with tibial insertion avulsion fracture of ACL involving the anterior root of LM who were treated with arthroscopic multi-point fixation with anchor and suture between October 2017 and January 2023. There were 12 males and 16 females with the mean age of 26 years (range, 13-57 years). There were 20 cases of sports injury and 8 cases of traffic accident injury. In 2 cases of old fracture, the time from injury to operation was 45 days and 90 days, respectively; in 26 cases of fresh fracture, the time from injury to operation was 3-20 days (mean, 6.7 days). According to the Meyers-McKeever classification, there were 4 cases of type Ⅱ, 11 cases of type Ⅲ, and 13 cases of type Ⅳ. The preoperative Lysholm knee function score was 42.1±9.0, the International Knee Documentation Committee (IKDC) score was 40.0±7.3, and the Tegner score was 0.7±0.7., Results: All operations were successfully completed, and the incisions healed by first intention. All the 28 patients were followed up 5-60 months (mean, 20.4 months). During the follow-up, there was nocomplication such as infection, vascular or nerve injury, loosening or breakage of internal fixator, or stiffness of knee joint. Postoperative X-ray films showed satisfactory fracture reduction and firm fixation. All fractures healed clinically, and the healing time was 8-16 weeks (mean, 10.3 weeks). At last follow-up, Lachman test and anterior drawer test were negative. At last follow-up, Lysholm knee function score was 92.4±5.5, IKDC score was 91.6±4.4, and Tegner score was 5.2±1.1, which significantly improved when compared with preoperative scores ( t =-22.899, P <0.001; t =-29.870, P <0.001; t =-19.979, P <0.001)., Conclusion: Multi-point fixation with anchor and suture in the treatment of tibial insertion avulsion fracture of ACL involving the anterior root of LM can not only fix the LM, but also effectively reduce and fix the avulsion fracture, which can obtain good effectiveness.

Objective: To investigate the effective of treating tibial eminence fracture in suture and wire fixation on arthroscopic. Methods: 87 patients of tibial eminence fracture cases collected from Jun 2012 to Dec 2013 in our hospital, which were divided into group A (n=40), group (37 cases)B according ways of fixation, which group A was given suture fixation, and group B wire fixation, observing reset condition after 3, 6, 12 months, including healing time, assess knee function, range of motion of the knee, surgery time and complications. Results: Preoperative and postoperative 3 months between Lysholm score was no significant difference (P>0.05), 6 and 12 months the difference was statistically significant (P<0.05); The two groups of Lysholm score were gradually increased in preoperative, comparative with postoperative, and the difference was statistically significant (P<0.05); Operative time had no significant difference in two groups (P>0.05), and patients knee a range of motion of the comparative group of patients was significantly better than group B(P<0.05),and healing time of A group shorter than group B group(P<0.05). Conclusions: Arthroscopic suture fixation between the tibial eminence fracture with less trauma, simple, fixed solid, beneficial joint early rehabilitation, can be widely used. [ABSTRACT FROM AUTHOR]

Objective To compare full-thickness suture （including endometrial layer） and split-thickness suture（excluding endometrial layer） on the formation of cesarean scar defect or diverticulums. Methods Two hundred primiparas who received caesarean section in Taiping Hospital of Dongguan and Houjie Hospital of Dongguan during April 2014 and December 2014 were enrolled in this study. The primiparas were randomly divided into observation group of 100 cases with full-thickness suture（including endometrial）， and control group of 100 cases with split-thickness suture（excluding endometrial layer），and the operation results and follow-up results were compared in the two groups. Results The average age of observation group was（25.5±3.2） years and （26.2±4.2） years in control group，with no significant difference between two groups（ = 0.1865），and there was no significant difference between two groups in operation duration，postoperative absorption heat，lochia days， 24 hours bleeding，postpartumhemoglobin （P > 0.05）. 9 months later，94 primiparas in observation group and 92 in control group were examined by transvaginal color Doppler ultrasound，Primiparas with CSD accounted for 25.5% in observation group，which was significantly lower than 40.2% in control group （ P＜0.05） . Conclusions The full-thickness suture（including endometrial layer） may be superior to split-thickness suture（excluding endometrial layer） in terms of CSD，and other risk factors were to be integrated to further explore the causes of CDS in future studies. [ABSTRACT FROM AUTHOR]

Objective This study aims to analyze the biomechanical effects of four sutures that are related to maxillary growth during a maxillary protraction treatment cycle based on labiolingual appliance. Methods A three-dimensional simulation of labiolingual appliance was performed based on a three-dimensional finite-element maxillofacial model combined with solid-modeled sutures. Results The displacement and stress distributions were calculated. The labiolingual appliance was suitable for patients with underbites or deep overbites. Sutura frontomaxillaris and sutura zygomaticomaxillaris were vital to the forward displacement and counterclockwise rotation of the maxillary. The changes in sutura zygomaticotempo-ralis and sutura palatine were not significant. Conclusion The influences of the labiolingual appliance on the sutures during the treatment cycle of maxillary protraction can be effectively simulated by the three-dimensional finite-element maxillofacial model. [ABSTRACT FROM AUTHOR]

PURPOSE: To explore an effective method to construct and validate a finite element model of the unilateral cleft lip and palate (UCLP) craniomaxillary complex with sutures, which could be applied in further three-dimensional finite element analysis (FEA). METHODS: One male patient aged 9 with left complete lip and palate cleft was selected and CT scan was taken at 0.75mm intervals on the skull. The CT data was saved in Dicom format, which was, afterwards, imported into Software Mimics 10.0 to generate a three-dimensional anatomic model. Then Software Geomagic Studio 12.0 was used to match, smoothen and transfer the anatomic model into a CAD model with NURBS patches. Then, 12 circum-maxillary sutures were integrated into the CAD model by Solidworks (2011 version). Finally meshing by E -feature Biomedical Modeler was done and a three --dimensional finite element model with sutures was obtained. A maxillary protraction force (500 g per side, 20°downward and forward from the occlusal plane) was applied. Displacement and stress distribution of some important craniofacial structures were measured and compared with the results of related researches in the literature. RESULTS: A three-dimensional finite element model of UCLP craniomaxillary complex with 12 sutures was established from the CT scan data. This simulation model consisted of 206 753 individual elements with 260 662 nodes, which was a more precise simulation and a better representation of human craniomaxillary complex than the formerly available FEA models. By comparison, this model was proved to be valid. CONCLUSIONS: It is an effective way to establish the three-dimensional finite element model of UCLP cranio-maxillary complex with sutures from CT images with the help of the following softwares: Mimics 10.0, Geomagic Studio 12.0, Solidworks and E-feature Biomedical Modeler. [ABSTRACT FROM AUTHOR]

PURPOSE: β-catenin, as a glycoprotein in cytoplasm, was involved in osteoblast development and bone formation. This study was designed to observe the spacial and temporal expression of β-catenin during premaxillary suture distraction osteogenesis in rat. METHODS: Thirty two female SD rats were randomly allotted into experimental group (n= 20) and control group (n=12). The experimental animals were subjected to premaxillary suture distraction by helix springs. They were sacrificed on the day l, 3, 5 and 7. Toluidine blue staining was used to observe the morphology and distribution of the osteoblasts. The expression of β-catenin and osteopontin (OPN) was identified by immunohistochemical staining. RESULTS: During nature growth, osteoblasts were sparsely lining along the premaxillary suture. β-catenin immunostaining was mainly localized in the membrane of these cells. The width of the suture was enlarged 1 day after distraction and osteoblasts were accumulated along the suture. Most of these osteoblasts showed positive OPN and β- catenin immunostaining. β-catenin signals were expressed additionally in the cytoplasm of the osteoblast and were more intensive in experimental sutures than those in control animals. New bone deposition was identified on the day 3 after suture distraction. Clusters of osteoblasts with weak OPN staining and strong β-catenin signals in cytoplasm were projected into the suture. On the day 5, the level of β-catenin expression began to decrease while intensive OPN staining was observed in the finger-shaped trabecular bone and those osteoblasts embedded in it. New bone formation was widespread in the expanded suture on the day 7. CONCLUSION: The expression level of β-catenin and the transition of the signals from membrane to cytoplasm along with the osteoblast maturation suggest that β-catenin might be involved in the regulation of osteoblast differentiation during premaxillary suture distraction osteogenesis in rat. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality (Grant No. 08DZ2271100 & 10QHI401600), Shanghai Leading Academic Discipline Project (Grant No. $30206) and Research Fund of Shanghai Municipal Education Commission (Grant No. 09YZ75). [ABSTRACT FROM AUTHOR]

PURPOSE: To identify the incidence of cell apoptosis during premaxillary suture expansion. METHODS: Forty SD rats were randomly allotted into experimental and control groups. The experimental animals were subjected to premaxillary suture expansion by a helix spring with (200 ± 10)g initial force. They were sacrificed on day 1, 2, 3 and 5(n=5). The sequence of histological changes and osteoblast proliferation in the premaxillary suture were evaluated by hematoxylin and eosin(HE) and toluidine blue staining. Cellular apoptosis was identified by ssDNA immunostaining. The difference between experimental and control groups was analyzed by Student's t test with SPSS 15.0 software package. RESULTS: The width of premaxillary suture was enlarged 1 day after expansion and osteoblasts were accumulated along the suture. After 2 days of stretching, the number of the osteoblasts increased to the peak. New bone deposition was identified on day 3 and projection of suture with bone trabeculae was apparent on day 5. ssDNA immunostaining showed few apoptotic cells in premaxillary suture during natural growth. Upon expansion, cell apoptosis was identified in osteoblasts along the suture and the osteocytes embedded in premaxillary bone, especially on day 2 and day 3 (P<0.01). CONCLUSION: Apoptotic cell death might regulate the growth modification of premaxillary suture upon mechanical stretching. [ABSTRACT FROM AUTHOR]

Suture broken, knot slipping and tissue tearing are the main reasons of wound closure failure in clinical operation. Based on this, we simulated the suturing and healing operation by using a biological materials testing machine and investigated the tensile properties before and after knotting, relaxation property and friction property of three common sutures: silk, polyglactin 910 and polypropylene. Results show that the tensile property decreased after knotting. The tensile strength of polyglactin 910 and elongation of polypropylene were the largest. During the relaxation process, the sutures relaxed the most in the first 2 hours. The relaxation from less to more was: polyglactin 910, silk and polypropylene. Coating or monofilament could obviously reduce the surface roughness of sutures, and thus reduce the friction force of the suture-suture interface. The friction force of the suture-suture interface increased with the increasing load but did no change with the increasing velocity. The results can provide an important theoretical basis for the optimizations of suture design and knotting operation.