Résumé
BACKGROUND:With computer-aided design,melt electrowriting technology can precisely construct 3D tissue engineering scaffolds with specific morphology,which has attracted increasing attention in tissue engineering. OBJECTIVE:To elaborate on the progress of melt electrowriting technology in tissue engineering in recent years. METHODS:PubMed and CNKI were used to retrieve articles about applications of melt electrowriting technology in tissue engineering.The search time was from March 2008 to February 2023.The search terms were"melt electrowriting,melt electrospinning,electrospinning,tissue engineering,scaffold,regeneration"in English and"melt electrowriting,electrospinning,tissue engineering"in Chinese.A preliminary screening of articles was performed by reading the titles and abstracts.Finally,69 articles were included for review. RESULTS AND CONCLUSION:(1)Melt electrowriting technology can achieve precise layer-by-layer deposition of fibers compared to traditional electrospinning technology,which better simulates the complex structure of natural tissues.Compared to other 3D printing technologies,smaller-diameter fibers can be prepared by melt electrowriting technology,resulting in highly ordered porous structures.(2)By combining with other scaffold preparation techniques or materials,such as fused deposition modeling,solution electrospinning technology,and hydrogel,melt electrowriting technology shows great potential in preparing complex tissue engineering scaffolds,which provides certain possibilities for achieving complex tissue regeneration.(3)The regeneration of complex tissues often involves blood vessels,nerves,and soft and hard tissues at the same time.The regeneration of blood vessels and nerves is of great significance to realize the physiological reconstruction of tissues.However,soft and hard tissues have certain difficulties to realize the coordinated regeneration of both due to their different biological and mechanical properties.Melt electrowriting technology has certain advantages in the field of bionic scaffolds due to its good biocompatibility,the ability to prepare multi-scale scaffolds and high porosity.
Résumé
Objective @# To investigate the impact of dexmedetomidine on the oncological behavior of hepatocellular carcinoma and explore the role of NF-E2-related factor 2 (Nrf2) at both in vitro and in vivo levels．@*Methods @# In vivo experiment，Male C57BL/6J mice were randomly divided into a control group ( Ctrl group) ，a hepatocellular carcinoma group ( HCC group) ，and a hepatocellular carcinoma + dexmedetomidine group ( HCC + Dex group) . Hepatocellular carcinoma was induced in mice by combining N-Nitrosodiethylamine ( DEN) / carbon tetrachloride ( CCl4 ) ，followed by daily intraperitoneal injection of 10% dexmedetomidine for two weeks．After feeding the mice for one month，the mice were assessed for the quantity and size of liver tumors．The proliferation ability of liver cancer was evaluated using Ki67 immunohistochemistry．Additionally，the expression level of Nrf2 protein in tumor tissue was measured through immunofluorescence．In vitro experiment，Hepa1-6 cells were incubated with different concentrations of dexmedetomidine (0. 1，1，5 nmol /L) for 48 hours to examine their effects．The proliferation， migration and invasion abilities of Hepa1-6 cells were evaluated using the MTT and Transwell methods．The expres- sion level of Nrf2 protein in the Hepa1-6 cells was measured using Western blot and immunofluorescence．Addition- ally，the proliferation ，migration and invasion abilities of cells were assessed after Nrf2 knockdown via si-RNA transfection，in combination with incubation with 1 nmol /L dexmedetomidine for 48 hours. @*Results @#ompared to the HCC group，the anatomical examination results revealed an increase in the number of liver tumors and the lon- gest diameter in the HCC + Dex group (P ＜0. 05) ． Ki67 immunohistochemistry results indicated the number of Ki67 positive cells in liver cancer tissue increased in the HCC + Dex group (P＜0. 01) ．The immunofluorescence assay demonstrated an upregulation of Nrf2 expression level in the HCC + Dex group (P ＜0. 05 ) ． MTT results showed that 1 nmol /L of dexmedetomidine increased the cell viability of Hepa1-6 cells (P＜0. 05) ．Transwell re- sults indicated that 0. 1 ，1 ，and 5 nmol /L of dexmedetomidine enhanced the invasive ability of Hepa1-6 cells， while 0. 1 and 1 nmol /L of dexmedetomidine enhanced the migration ability (P＜0. 05) ．Western blot and immu- nofluorescence results showed an upregulation of Nrf2 expression level in cells after treatment with 1 nmol /L dexme- detomidine (P＜0. 01) ．The Nrf2 expression level of cells was reduced using si-RNA，followed by treatment with 1 nmol /L dexmedetomidine．The results from MTT and Transwell assays revealed a decrease in the viability，invasion and migration ability of Hepa1-6 cells (P＜0. 01) ．@*Conclusion @# Dexmedetomidine may enhance the proliferation， invasion and migration capacity of hepatocellular carcinoma by upregulating the expression of Nrf2 .