1.Construction of human Egr-1 promoter and its response to ionizing radiation in tumor cells
Xiaojie XU ; Lihua DING ; Lingxue WANG ; Xi QIN ; Long CHENG ; Kai JIANG ; Qinong YE
Journal of Cellular and Molecular Immunology 2009;25(11):973-975
AIM: To construct human Egr-1 promoter luciferase reporter system and study its activity induced by i-onizing radiation. METHODS: Egr-1 promoter was obtained by human genomic PCR and cloned into pGL3-basic vector. After transfection of recombinant plasmid into human tumor cells, the Egr-1 promoter activity induced by ionizing radiation was detected by luciferase reporter assay. RESULTS: The luciferasy reporter system of Egr-1 promoter was successfully constructed. The activity of Egr-1 promoter was substantially increased after different doses of IR and reached to the peak at the time point of 48h after IR. CONCLUSION: The Egr-1 promoter was constructed in this study showed IR inducible activity in tumor cells, laying foundation for the research of radiation, mediated gene therapy.
2.Gradient artificial bone repair scaffold regulates skeletal system tissue repair and regeneration
Yu ZHANG ; Ruian XU ; Lei FANG ; Longfei LI ; Shuyan LIU ; Lingxue DING ; Yuexi WANG ; Ziyan GUO ; Feng TIAN ; Jiajia XUE
Chinese Journal of Tissue Engineering Research 2025;29(4):846-855
BACKGROUND:Gradient artificial bone repair scaffolds can mimic unique anatomical features in musculoskeletal tissues,showing great potential for repairing injured musculoskeletal tissues. OBJECTIVE:To review the latest research advances in gradient artificial bone repair scaffolds for tissue engineering in the musculoskeletal system and describe their advantages and fabrication strategies. METHODS:The first author of the article searched the Web of Science and PubMed databases for articles published from 2000 to 2023 with search terms"gradient,bone regeneration,scaffold".Finally,76 papers were analyzed and summarized after the screening. RESULTS AND CONCLUSION:(1)As an important means of efficient and high-quality repair of skeletal system tissues,gradient artificial bone repair scaffolds are currently designed bionically for the natural gradient characteristics of bone tissue,bone-cartilage,and tendon-bone tissue.These scaffolds can mimic the extracellular matrix of native tissues to a certain extent in terms of structure and composition,thus promoting cell adhesion,migration,proliferation,differentiation,and regenerative recovery of damaged tissues to their native state.(2)Advanced manufacturing technology provides more possibilities for gradient artificial bone repair scaffold preparation:Gradient electrospun fiber scaffolds constructed by spatially differentiated fiber arrangement and loading of biologically active substances have been developed;gradient 3D printed scaffolds fabricated by layered stacking,graded porosity,and bio-3D printing technology;gradient hydrogel scaffolds fabricated by in-situ layered injections,simple layer-by-layer stacking,and freeze-drying method;and in addition,there are also scaffolds made by other modalities or multi-method coupling.These scaffolds have demonstrated good biocompatibility in vitro experiments,were able to accelerate tissue regeneration in small animal tests,and were observed to have significantly improved histological structure.(3)The currently developed gradient artificial bone repair scaffolds have problems such as mismatch of gradient scales,unclear material-tissue interactions,and side effects caused by degradation products,which need to be further optimized by combining the strengths of related disciplines and clinical needs in the future.