| BackgroundSuitable tumor models in vitro for drug screening can improve the success rate of preclinical trials and reduce the cost of drug research and development.3D bioprinting is a convenient,efficient,economical and standardized cutting-edge technology.In addition to organ biomimetic medicine,scholars have recognized the potential value of 3D bioprinting technology in tumor research and drug screening.Researches on 3D bioprinting focus on optimization of printing process,selection of bio-ink and evaluation of cell survival status,but there is still a lack of comprehensive and in-depth research on biological function evaluation and drug testing of 3D bioprinting tumor models.In this study,3D bioprinting colorectal cancer model was compared with 2D culture model and 3D culture model.The morphological and biological characteristics of the three culture models were evaluated.The multicellular drug screening model of colorectal cancer was constructed based on 3D bioprinting technology.And tumor cell and stromal cell coculture model was developed.MethodsWe used SW480 as colorectal cancer seed cells and gelatin/sodium alginate as bio-ink to construct a single cell model of colorectal cancer by 3D bio-printer.By testing and optimizing the printing model design,bio-ink configuration,cell concentration ratio,printing platform temperature,and line width,the optimal experimental parameters of 3D bioprinting single cell model for colorectal cancer were determined.The stability of 3D bioprinting model was comprehensively understood from morphological observation under light microscope,cell survival staining,cell proliferation assay,immunofluorescence staining,cryo-histopathological HE staining and other aspects.After the successful construction of single cell model,tumor-associated macrophages and human umbilical vein endothelial cells will be added,and three-dimensional concentric circle multicellular drug screening model of colorectal cancer will be constructed for the first time by dual-spray coaxial 3D bio-printer.The stability of the multicellular model was evaluated by cell proliferation assay,cell survival staining,immunofluorescence,and HE staining of frozen histopathology.Transcriptome sequencing technology was used to understand the up-regulation and down-regulation of differential gene expression in 2D culture group,3D culture group,3D printing single cell group and 3D printing multicellular group.GO enrichment analysis was used to understand the differences of gene expression in biological process,cell composition and molecular function classification under different culture modes.KEGG enrichment analysis was used to identify the signaling pathways with the most differentially enriched genes in different culture modes.Finally,drug screening tests of 5-FU,oxaliplatin and irinotecan were conducted to compare the differences of drug reactions in 2D culture,3D printing single cell group and 3D printing multicellular group.ResultsWe constructed a 3D bioprinting colorectal cancer model using 12%gelatin and 4%sodium alginate as bio-ink.Under light microscope,colorectal cancer cells grew stably and formed tumor cell masses in 3D bioprinting model.The survival rate of colorectal cancer cells printed in vivo from day 1 to 10 was as high as more than 90%.By CCK8 measurement of cell proliferation,it was found that the cell proliferation level of 3D bioprinting group was not lower than that of 3D culture group,and Ki67 staining of tumor cells was strongly positive on the 7th day of culture.We successfully made frozen pathology of 3D bioprinting tissue,and observed the morphological characteristics of tumor cells and stromal cells by HE staining.KEGG enrichment analysis suggested that the up-regulated differential gene enrichment pathways included PD-L1/PD-1 checkpoint pathway and EGFR receptor tyrosine kinase inhibitor resistance pathway in colorectal cancer cells from the 3D printing multicellular group compared with the 3D printing single-cell group.The anti-tumor drug screening experiment showed that the IC50 values of 5-FU,oxaliplatin and irinotecan in 3D printing single cell group/2D culture group were 31.13um/12.79um,26.79um/0.80um and 16.73um/10.45m,respectively.Compared with the 3D bio-printing single cell group,the 3D printing multicellular group was significantly resistant to chemotherapy,and the drug inhibition response was not obvious.ConclusionsIn this study,a multicellular drug screening model for colorectal cancer was successfully constructed based on 3D bioprinting technology.The performance of 3D bioprinting multicellular drug screening model in cell proliferation and cell survival was no less than or even better than that of 3D culture model.Transcriptome sequencing results indicated that there were many different genes in cell composition,molecular function and biological function between 3D bioprinting single cell group and 2D culture group.In terms of drug response experiment,compared with the 2D culture model,the IC50 value of chemotherapy drugs in the 3D printed single-cell colorectal cancer model was closer to the effective blood drug concentration of human body.In particular,3D bioprinting multicellular colorectal cancer drug screening models showed greater drug resistance.3D bioprinting has potential advantages in drug development and precision therapy.ObjectivesThe purpose of this prospective study was to monitor the activity status of patients after colorectal cancer by wearable devices.We planned to explore the relationship between postoperative activity and lung ultrasound score,so as to predict patients’ perioperative complications more accurately and conveniently in clinical work.MethodsThis study included a total of 101 patients undergoing colorectal surgery in our hospital.Bedside lung ultrasound was performed on each patient at a fixed time one day before surgery and the first five days after surgery,to evaluate the lung situation at 12 sites,including superior anterior chest,inferior anterior chest,superior lateral chest,inferior lateral chest,superior posterior chest and inferior posterior chest,and to record the lung score.Perioperative pulmonary complications were collected and recorded.ResultsThirteen patients presented with pulmonary complications among the 101 patients included in the study.The mean postoperative peak lung ultrasound score of all patients was 5.32±2.52.Through single-factor logistics regression,we found that patients with high pulmonary ultrasound score were correlated with the occurrence of pulmonary complications after colorectal surgery,with a regression coefficient of 1.715 and an OR value of 5.556.As the number of days increased,the daily walking distance of patients in the first 4 days kept increasing.The daily walking distance of patients in the first 4 days was statistically different,P<0.05.Spearman rank correlation analysis showed that postoperative walking distance was negatively correlated with lung ultrasound score,and the correlation coefficient was-0.356,the difference was statistically significant,P<0.05.ConclusionsThis study verified that pulmonary ultrasound can be used as a convenient and effective means to evaluate the pulmonary condition of patients underwent colorectal surgery.The number of daily steps taken to the ground after surgery will affect the lung ultrasound score of patients.Therefore,the patients should be encouraged to move to the ground in the first 2 days after surgery,especially the high-risk group whose score is overObjectivesThe incidence of retrorectal lesions is low,and no consensus has been reached regarding the most optimal surgical approach.Laparoscopic approach has the advantage of minimally invasive.The risk factors influencing perioperative complications of laparoscopic surgery are rarely discussed and analysed.MethodsWe retrospectively reviewed the medical records of patients who underwent laparoscopic excision of retrorectal cystic lesions at our colorectal surgery.All included patients were divided into groups based on the lesion location and tumor diameter.We analysed the risk factors like the history of abdominal surgery,previous treatment,clinical manifestation,operation duration,blood loss,perioperative complications,and readmission rate within 90 days retrospectively.ResultsSevere perioperative complications occurred in seven patients.We performed prophylactic transverse colostomy in four patients who were suspected rectal injury.Two patients underwent puncture drainage due to postoperative pelvic infection.One patient underwent debridement in the operating room due to incision infection.The massive-lesion group had a significantly longer surgery duration,higher blood loss,higher incidence of perioperative complications,and higher readmission rate within 90 days(P<0.05).Logistic regression showed that lesion diameter was an independent risk factor for the development of perioperative complications in patients who underwent laparoscopic excision of retrorectal cystic lesions.ConclusionsThe diameter of the lesion is an independent risk factor for perioperative complications in patients who undergo laparoscopic excision of retrorectal cystic lesions.Laparoscopic surgery is minimally invasive,high-resolution,and flexible,and its use in retrorectal cystic lesions is safe and feasible,also for lesions below the S3 level. |
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