摘要：Three-dimensional(3D)bioprinting is a powerful approach that enables the fabrication of 3D tissue constructs that retain complex biological ***,the dense hydrogel networks that form after the gelation of bioinks often restrict the migration and proliferation of encapsulated ***,a sacrificial microgel-laden bioink strategy was designed for directly bioprinting constructs with mesoscale pore networks(MPNs)for enhancing nutrient delivery and cell *** sacrificial microgel-laden bioink,which contains cell/gelatin methacryloyl(GelMA)mixture and gelled gelatin microgel,is first thermo-crosslinked to fabricate temporary predesigned cell-laden constructs by extrusion bioprinting onto a cold ***,the construct is permanently stabilized through photo-crosslinking of *** MPNs inside the printed constructs are formed after subsequent dissolution of the gelatin *** MPNs allowed for effective oxygen/nutrient diffusion,facilitating the generation of bioactive ***,osteoblast and human umbilical vein endothelial cells encapsulated in the bioprinted large-scale constructs(≥1 cm)with MPNs showed enhanced bioactivity during *** 3D bioprinting strategy based on the sacrificial microgel-laden bioink provided a facile method to facilitate formation of complex tissue constructs with MPNs and set a foundation for future optimization of MPN-based tissue constructs with applications in diverse areas of tissue engineering.

摘要：Liver injury is a common cause of drug approval withdrawal during drug development,pre-clinical research,and clinical *** not properly treated,patients with severe liver injury can suffer from acute liver failure or even ***,utilization of the convenient in vitro hepatotoxicity assessment model for early detection of drug-induced hepatotoxicity is vital for drug development and safe personalized ***(e.g.,hydrogels,nanofibers,decellularized liver matrix)and bioengineering technologies(e.g.,microarrays,micropatterns,3D printing,and microfluidics)have been applied for in vitro hepatotoxicity assessment *** review summarizes the structure and functions of the liver as well as the components of in vitro hepatotoxicity assessment *** addition,it highlights the latest advances in developing hepatotoxicity models with the ultimate goal of further clinical translation.

摘要：The organized alignment of cells in various tissues plays a significant role in the maintenance of specific *** induce such an alignment,ideal scaffolds should simulate the characteristics and morphologies of natural *** structures that guide cell orientation are used to facilitate tissue regeneration and *** here review how various aligned structures are fabricated,including aligned electrospun nanofibers,aligned porous or channeled structures,micropatterns and combinations thereof,and their application in nerve,skeletal muscle,tendon,and tubular dentin *** future use of aligned structures in tissue engineering is also discussed.

摘要：To create a scaffold that is suitable for the construction of tissue-engineered skin, a novel asymmetric porous scaffold with different pore sizes on either side was prepared by combining a collagen-chitosan porous membrane with fibrin glue. Tissue-engineered skin was fabricated using this asymmetric scaffold, fibroblasts, and a human keratinocyte line (HaCaT). Epidermal cells could be seen growing easily and achieved confluence on the fibrin glue on the upper surface of the scaffold. Scanning electron microscopy showed typical shuttle-like fibroblasts adhering to the wall of the scaffold and fluorescence microscopy showed them growing in the dermal layer of the scaffold. The constructed composite skin substitute had a histological structure similar to that of normal skin tissue after three weeks of culture. The results of our study suggest that the asymmetric scaffold is a promising biologically functional material for skin tissue engineering, with prospects for clinical applications.

摘要：For most organisms,molecular oxygen is indispensable for normal physiological metabolism;in humans,prolonged hypoxia in tissues can induce many diseases,exemplified by cardiovascular disease,chronic wounds,and tissue ***,the oxygen in our environment is vital for *** a main source of oxygen in the natural world that transforms light energy into chemical energy and oxygen,photosynthesis has been widely studied in scientific research and used in production of food,fuel,and *** recent years,photosynthesis has become more closely involved in biomedicine and has been widely used in photodynamic therapy,tissue regeneration,transplantation,and in treatment of specific *** review summarizes innovative applications of photosynthesis in biomedical research and highlights the theory and implications of clinical treatment for specific diseases.

摘要：Treatments for lesions in central nervous system(CNS)are always faced with challenges due to the anatomical and physiological particularity of the CNS despite the fact that several achievements have been made in early diagnosis and precision medicine to improve the survival and quality of life of patients with brain tumors in recent *** the complexity as well as role of the microenvironment of brain tumors may suggest a better revealing of the molecular mechanism of brain tumors and new therapeutic directions,which requires an accurate recapitulation of the complex microenvironment of human brain in ***,a 3D bioprinted in vitro brain matrix-mimetic microenvironment model with hyaluronic acid(HA)and normal glial cells(HEBs)is developed which simulates both mechanical and biological properties of human brain microenvironment in vivo through the investigation of the formulation of bioinks and optimization of printing process and parameters to study the effects of different concentration of gelatin(GA)within the bioink and different printing structures of the scaffold on the performance of the brain matrix-mimetic microenvironment *** study provides experimental models for the exploration of the multiple factors in the brain microenvironment and scaffolds for GBM invasion study.

摘要：Tracheal stents are an important form of treatment for benign or malignant central airway ***,the mechanical behavior of current tracheal stents is significantly different from that of the native trachea,which leads to a variety of serious *** this study,inspired by the structure of the native trachea,a wavy non-uniform ligament chiral tracheal stent is proposed,in which J-shaped stress-strain behavior and negative Poisson's ratio response are achieved by replacing the tangential ligament of tetrachiral and anti-tetrachiral hybrid structure with a wavy non-uniform *** the combination of theoretical analysis,finite element analysis and experimental tests,a wide range of desired J-shaped stress-strain curves are explored to mimic the native porcine trachea by tailoring the stent ***,the negative Poisson’s ratio and auxetic diameter curves versus axial strain of the stent are also studied in detail,thus contributing to the enhancement of cross-section ventilation and reducing the migration of the *** novel tracheal stent with a unique microstructure shows a potential to perfectly match the physiological activities of the native trachea and thereby reduce potential complications.

摘要：Previous studies have suggested that the transforming growth factor- $$\upbeta $$ receptor ALK5 is crucial for articular chondrogenesis by bone marrow mesenchymal stem cells. Here, the wild-type ALK5 plasmids were mutated by overlapping extended PCR and transfected into bone marrow mesenchymal stem cells. The knee joint osteoarthritis mouse model was constructed by cutting off the anterior cruciate ligament and divided into three groups: saline group, bone marrow mesenchymal stem cells and ALK5-transfected bone marrow mesenchymal stem cells group. HE staining showed that the articular cartilage lesions were more serious of saline group compared with that of mesenchymal stem cell group, and this trend was more pronounced as time goes on. Immunohistochemical staining showed that although the expression level of type II collagen in all three groups down-regulated gradually upon time, its expression in ALK5-transfected bone marrow mesenchymal stem cells group was significantly enhanced compared with the other two groups. Micro-CT also suggested that ALK5 transfection of mouse bone marrow mesenchymal stem cells would promote repairing the knee cartilage lesions with arthritis of the mice. Although the osteoarthritis mechanism underlying a variety of factors work together, and the appropriate proportion of ALK5/ALK1 was also emphasized for the treatment of osteoarthritis. This work therefore demonstrated that ALK5 transfection of bone marrow mesenchymal stem cells could be a promising stem cell therapy for repair of cartilage lesions.

摘要：AIM: To evaluate contrast visual acuity(CVA) after implantation of an aspheric apodized diffractive intraocular lens(IOL) or a spherical apodized diffractive IOL in cataract surgery. ·METHODS: This prospective randomized controlled study with a 12-month follow-up compared the results of cataract surgery with implantation of an aspheric AcrySof ReSTOR SN6AD3 IOL(30 eyes) and a spherical AcrySof ReSTOR SN60D3 IOL(30 eyes). CVA with best distance correction was measured at 4 contrast levels(100%,25%,10% and 5%) under 3 levels of chart luminance [250,85 and 25 candelas per square meter(cd/m2)] using a multi-functional visual acuity tester(MFVA-100). ·RESULTS: At 12 months after surgery,there were no statistically significant differences in 100% CVA and 25% CVA under 250cd/m2(P100% =0.875 and P25% =0.057) and 85cd/m2(P100% =0.198 and P25% =0.193) between the aspheric group and the spherical group. However,the 10% CVA and 5% CVA were significant better in aspheric group than spherical group under 250cd/m2(P10% =0.042 and P5% = 0.007) and 85cd/m2(P10% =0.002 and P5%=0.039). Under the luminance level of 25cd/m 2,no significant differences was found in the 100% CVA between the 2 group(P100% = 0.245),while aspheric group had better visual acuity in the remaining 3 contracts(P25% =0.023,P10% =0.026 and P5% = 0.002,respectively). ·CONCULSION: The aspheric AcrySof ReSTOR SN6AD3 IOL provided patients with better low-contrast visual acuity than the spherical AcrySof ReSTOR SN60D3 IOL.

摘要：Classification of 3D bioprinting As we mentioned in the last editorial,3D printing,also known as additive manufacturing,could be considered as the reverse process of potato cutting,automatically assembling sliced potato,shredded potato,diced potato to integrity[1].Generally speaking,cell-laden 3D bioprinting can be classified into three types:extrusion-based,droplet-based and photocuring-based bioprinting according to different printing ***-based bioprinting squeezes out continuous hydrogel fibers to set up structures;dropletbased bioprinting generates droplets as the basic unit for biofabrication;and photocuring-based bioprinting utilizes the characteristics of light-sensitive materials,to stack 3D models *** bioprinting approaches own diverse characteristics facing various scenarios and have specific requirements for bioinks.