3D bioprinting of in vitro porous hepatoma models:establishment,evaluation,and anticancer drug testing

Traditional tumor models do not tend to accurately simulate tumor growth in vitro or enable personalized treatment and are particularly unable to discover more beneficial targeted drugs.To address this,this study describes the use of threedimensional(3D)bioprinting technology to construct a 3D model with human hepatocarcinoma SMMC-7721 cells(3DP-7721)by combining gelatin methacrylate(GelMA)and poly(ethylene oxide)(PEO)as two immiscible aqueous phases to form a bioink and innovatively applying fluorescent carbon quantum dots for long-term tracking of cells.The GelMA(10%,mass fraction)and PEO(1.6%,mass fraction)hydrogel with 3:1 volume ratio offered distinct pore-forming characteristics,satisfactorymechanical properties,and biocompatibility for the creation of the 3DP-7721 model.Immunofluorescence analysis and quantitative real-time fluorescence polymerase chain reaction(PCR)were used to evaluate the biological properties of the model.Compared with the two-dimensional culture cell model(2D-7721)and the 3D mixed culture cell model(3DM-7721),3DP-7721 significantly improved the proliferation of cells and expression of tumor-related proteins and genes.Moreover,we evaluated the differences between the three culture models and the effectiveness of antitumor drugs in the three models and discovered that the efficacy of antitumor drugs varied because of significant differences in resistance proteins and genes between the three models.In addition,the comparison of tumor formation in the three models found that the cells cultured by the 3DP-7721 model had strong tumorigenicity in nude mice.Immunohistochemical evaluation of the levels of biochemical indicators related to the formation of solid tumors showed that the 3DP-7721 model group exhibited pathological characteristics of malignant tumors,the generated solid tumors were similar to actual tumors,and the deterioration was higher.This research therefore acts as a foundation for the application of 3DP-7721 models in drug development research.

Recent Advances on Challenges and Strategies of Manganese Dioxide Cathodes for Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries(AZIBs)are regarded as promising electrochemical energy storage devices owing to its low cost,intrinsic safety,abundant zinc reserves,and ideal specific capacity.Compared with other cathode materials,manganese dioxide with high voltage,environmental protection,and high theoretical specific capacity receives considerable attention.However,the problems of structural instability,manganese dissolution,and poor electrical conductivity make the exploration of high-performance manganese dioxide still a great challenge and impede its practical applications.Besides,zinc storage mechanisms involved are complex and somewhat controversial.To address these issues,tremendous efforts,such as surface engineering,heteroatoms doping,defect engineering,electrolyte modification,and some advanced characterization technologies,have been devoted to improving its electrochemical performance and illustrating zinc storage mechanism.In this review,we particularly focus on the classification of manganese dioxide based on crystal structures,zinc ions storage mechanisms,the existing challenges,and corresponding optimization strategies as well as structure-performance relationship.In the final section,the application perspectives of manganese oxide cathode materials in AZIBs are prospected.

脊髓性肌萎缩症SMN1基因2+0基因型携带者的家系研究

脊髓性肌萎缩症(spinal muscular atrophy, SMA)是一种儿童时期较为常见的神经肌肉病,属于常染色体隐性遗传。绝大多数SMA由运动神经元存活基因1 (survival motor neuron 1, SMN1)的纯合缺失突变所致。而SMN1的2+0基因型个体作为一种特殊的SMA携带者,给携带者筛查以及家系的遗传咨询带来了巨大的挑战。已有研究表明,g.27134T>G和g.27706_27707delAT多态位点变异对于Ashkenazi犹太人群中的2+0基因型个体具有提示作用。为进一步探究这两个多态位点是否在中国人群也具有特异性,本研究纳入了44例家系成员和204例已知SMN1基因拷贝数的对照样本。44例家系成员来自于9个无关的SMN1基因纯合缺失的SMA家系,先证者双亲之一疑似为2+0基因型携带者。利用多重连接探针扩增(multiplex ligation-dependent probe amplification,MLPA)和短串联重复(short tandem repeat, STR)连锁分析进行基因型的鉴定以及多态位点的筛查,最终通过对家系三代成员或多子女家系两代成员的分析确定了9个家系中的10例个体为2+0基因型携带者,多态位点筛查显示1例携带3拷贝SMN1基因的个体同时存在g.27134T>G和g.27706_27707delAT多态位点的变异。因此,本研究通过对2+0基因型携带者的鉴定,为家系遗传病的诊断提供了精准的遗传咨询。g.27134T>G和g.27706_27707delAT多态位点可能与中国人群2+0基因型个体的关联度较低,尚需寻找中国人群特异的多态位点以提高2+0基因型携带者的检出率。

A case of spontaneous hepatic hemangioma rupture:Successful management with transarterial chemoembolization alone

Hemangioma is the most common benign hepatic tumor.Although spontaneous rupture is rare,the mortality rate ranges from 60 to 75%.Only 34 cases have been reported in the literature,with only one report using transcatheter arterial embolization(TAE) alone as treatment.We report a case of spontaneous rupture with "flowering sign" of a giant hepatic hemangioma,presenting with acute abdominal pain and shock,while the volume of the hemangioma and blood loss were similar.The patient was successfully managed by transarterial chemoembolization(TACE) alone,which has an operative mortality rate of up to 36.4%.

Phase-Gradient Metasurfaces Based on Local Fabry–Perot Resonances

In this work,we present a new mechanism for designing phase-gradient metasurfaces(PGMs)to control an electromagnetic wavefront with high efficiency.Specifically,we design a transmission-type PGM,formed by a periodic subwavelength metallic slit array filled with identical dielectrics of different heights.It is found that when Fabry-Perot(FP)resonances occur locally inside the dielectric regions,in addition to the common phenomenon of complete transmission,the transmitted phase differences between two adjacent slits are exactly the same,being a nonzero constant.These local FP resonances ensure total phase shift across a supercell,fully covering a range of 0 to 2π,satisfying the design requirements of PGMs.Further research reveals that,due to local FP resonances,there is a one-to-one correspondence between the phase difference and the permittivity of the filled dielectric.A similar approach can be extended to the reflection-type case and other wavefront transformations,creating new opportunities for wave manipulation.

High-performance flexible organic field effect transistors with print-based nanowires

Polymer nanowire(NW)organic field-effect transistors(OFETs)integrated on highly aligned large-area flexible substrates are candidate structures for the development of high-performance flexible electronics.This work presents a universal technique,coaxial focused electrohydrodynamic jet(CFEJ)printing technology,to fabricate highly aligned 90-nm-diameter polymer arrays.This method allows for the preparation of uniformly shaped and precisely positioned nanowires directly on flexible substrates without transfer,thus ensuring their electrical properties.Using indacenodithiophene-co-benzothiadiazole(IDT-BT)and poly(9,9-dioctylfluorene-co-benzothiadiazole)(F8-BT)as example materials,5 cm^(2) arrays were prepared with only minute size variations,which is extremely difficult to do using previously reported methods.According to 2D-GIXRD analysis,the molecules inside the nanowires mainly adopted face-onπ-stacking crystallite arrangements.This is quite different from the mixed arrangement of thin films.Nanowire-based OFETs exhibited a high average hole mobility of 1.1 cm^(2) V^(−1) s^(−1) and good device uniformity,indicating the applicability of CFEJ printing as a potential batch manufacturing and integration process for high-performance,scalable polymer nanowire-based OFET circuits.This technique can be used to fabricate various polymer arrays,enabling the use of organic polymer semiconductors in large-area,high-performance electronic devices and providing a new path for the fabrication of flexible displays and wearable electronics in the future.

A targeted sequencing approach to find novel pathogenic genes associated with sporadic aortic dissection

Aortic dissection(AD) is a heterogeneous genetic disease of the aorta with high mortality and poor prognosis. However, only few genetic causes of AD have been explored till date. After conducting a broad literature review focused on identifying potential pathogenic pathways, we designed a panel containing 152 AD-associated genes to conduct massively parallel targeted nextgeneration sequencing of 702 sporadic aortic dissection patients and 163 matched healthy controls. After validation by Sanger sequencing, we identified 21 definitely pathogenic and 635 likely pathogenic variants in 61.25%(430/702) of patients. In these patients, 34.88%(150/430) harbored more than one variant that was either definitely or likely to be pathogenic. Among the candidate genes, we identified 546 likely pathogenic variants in 47.72%(335/702) of patients. Importantly, we identified 94 lossof-function(LOF) variants in 45 genes in AD patients, but only five LOF variants in the controls(P=1.34×10^(-4)). With a burden test, we highlighted RNF213 as an important new gene for AD pathogenesis. We also performed transcriptome sequencing of human aorta tissues to evaluate the expression levels of these newly identified genes. Our study has compiled a comprehensive genetic map of sporadic AD in the Han Chinese population. We believe it will facilitate risk predicting and genetic diagnosis of this severe disease in the future.

Antifogging properties and mechanism of micron structure in Ephemera pictiventris McLachlan compound eyes

An antifogging function surface with simple structure and suitable for large-area production was found inspired by Ephemera pictiventris McLachlan compound eyes.The compound eyes structure,antifogging properties and mechanism were studied by anti-fog test,dyeing test and scanning electron microscopy,and so forth.Then,3D model of the sample was established,and the antifogging mechanism was explained by the Cassie model.Results showed that the compound eyes are composed of hundreds of micron size ommatidia arranged in curved array form,and this structure shows excellent antifogging function.This research may provide new ideas for design of simple structure and micron size antifogging function surface.This work is also expected to be applied to antifogging function surface of astronaut helmets and medical endoscopes,and so forth.

Variants of genes encoding collagens and matrix metalloproteinase system increased the risk of aortic dissection

Aortic dissection(AD) is a devastating,heterogeneous condition of aorta.The homeostasis between collagens and matrix metalloproteases(MMPs)/tissue inhibitors of MMPs(TIMPs) system in the extracellular matrix plays an important role for structure and functions of aorta.However,our knowledge on association between variants of genes in this system and pathogenesis of AD is very limited.We analyzed all yet known coding human genes of collagens(45 genes),MMPs/TIMPs(27genes) in 702 sporadic AD patients and in 163 matched healthy controls,by using massively targeted next-generation and Sanger sequencing.To define the pathogenesis of potential disease-causing candidate genes,we performed transcriptome sequencing and pedigree co-segregation analysis in some genes and generated Col5a2 knockout rats.We identified 257 pathogenic or likely pathogenic variants which involved 88.89%(64/72) genes in collagens-MMPs/TIMPs system and accounted for 31.05%(218/702) sporadic AD patients.In them,84.86%patients(185/218) carried one variant,12.84%two variants and 2.30%more than two variants.Importantly,we identified 52 novel probably pathogenic loss-of-function(LOF) variants(20 nonsense,16 frameshift,14 splice sites,one stop-loss,one initiation codon) in 11.06%(50/452) AD patients,which were absent in 163controls(P=2.5×10^(-5)).Transcriptome sequencing revealed that identified variants induced dyshomeostasis in expression of collagens-TIMPs/MMPs systems.The Col5α2^(-/-) rats manifested growth retardation and aortic dysplasia.Our study provides a first comprehensive map of genetic alterations in collagens-MMPs/TIMPs system in sporadic AD patients and suggests that variants of these genes contribute largely to AD pathogenesis.

Biocompatible chitosan/polyethylene glycol/multi-walled carbon nanotube composite scaffolds for neural tissue engineering

Carbon nanotube(CNT)composite materials are very attractive for use in neural tissue engineering and biosensor coatings.CNT scaffolds are excellent mimics of extracellular matrix due to their hydrophilicity,viscosity,and biocompatibility.CNTs can also impart conductivity to other insulating materials improve mechanical stability guide neuronal cell behavior and trigger axon regeneration.The performance of chitosan(CS)/polyethylene glycol(PEG)composite scaffolds could be optimized by introducing multi-walled CNTs(MWCNTs).CS/PEG/CNT composite scaffolds with CNT content of 1%,3%,and 5%(1%=0.01 g/mL)were prepared by freeze-drying.Their physical and chemical properties and biocompatibility were evaluated.Scanning electron microscopy(SEM)showed that the composite scaffolds had a highly connected porous structure.Transmission electron microscope(TEM)and Raman spectroscopy proved that the CNTs were well dispersed in the CS/PEG matrix and combined with the CS/PEG nanofiber bundles.MWCNTs enhanced the elastic modulus of the scaffold.The porosity of the scaffolds ranged from 83%to 96%.They reached a stable water swelling state within 24 h,and swelling decreased with increasing MWCNT concentration.The electrical conductivity and cell adhesion rate of the scaffolds increased with increasing MWCNT content.Immunofluorescence showed that rat pheochromocytoma(PC12)cells grown in the scaffolds had characteristics similar to nerve cells.We measured changes in the expression of nerve cell markers by quantitative real-time polymerase chain reaction(qRT-PCR),and found that PC12 cells cultured in the scaffolds expressed growth-associated protein 43(GAP43),nerve growth factor receptor(NGFR),and class IIIβ-tubulin(TUBB3)proteins.Preliminary research showed that the prepared CS/PEG/CNT scaffold has good biocompatibility and can be further applied to neural tissue engineering research.

Mesenchymal stem cells loaded on 3D-printed gradient poly(e-caprolactone)/methacrylated alginate composite scaffolds for cartilage tissue engineering

Cartilage has limited self-repair ability due to its avascular,alymphatic and aneural features.The combination of three-dimensional(3D)printing and tissue engineering provides an up-and-coming approach to address this issue.Here,we designed and fabricated a tri-layered(superficial layer(SL),middle layer(ML)and deep layer(DL))stratified scaffold,inspired by the architecture of collagen fibers in native cartilage tissue.The scaffold was composed of 3D printed depth-dependent gradient poly(e-caprolactone)(PCL)impregnated with methacrylated alginate(ALMA),and its morphological analysis and mechanical properties were tested.To prove the feasibility of the composite scaffolds for cartilage regeneration,the viability,proliferation,collagen deposition and chondrogenic differentiation of embedded rat bone marrow mesenchymal stem cells(BMSCs)in the scaffolds were assessed by Live/dead assay,CCK-8,DNA content,cell morphology,immunofluorescence and real-time reverse transcription polymerase chain reaction.BMSCs-loaded gradient PCL/ALMA scaffolds showed excellent cell survival,cell proliferation,cell morphology,collagen II deposition and hopeful chondrogenic differentiation compared with three individual-layer scaffolds.Hence,our study demonstrates the potential use of the gradient PCL/ALMA construct for enhanced cartilage tissue engineering.

3D printed-electrospun PCL/hydroxyapatite/MWCNTs scaffolds for the repair of subchondral bone

Osteochondral defect caused by trauma or osteoarthritis exhibits a major challenge in clinical treatment with limited symptomatic effects at present.The regeneration and remodeling of subchondral bone play a positive effect on cartilage regeneration and further promotes the repair of osteochondral defects.Making use of the strengths of each preparation method,the combination of 3D printing and electrospinning is a promising method for designing and constructing multi-scale scaffolds that mimic the complexity and hierarchical structure of subchondral bone at the microscale and nanoscale,respectively.In this study,the 3D printed-electrospun poly(ɛ-caprolactone)/nano-hydroxyapatites/multi-walled carbon nanotubes(PCL/nHA/MWCNTs)scaffolds were successfully constructed by the combination of electrospinning and layer-by-layer 3D printing.The resulting dual-scale scaffold consisted of a dense layer of disordered nanospun fibers and a porous microscale 3D scaffold layer to support and promote the ingrowth of subchondral bone.Herein,the biomimetic PCL/nHA/MWCNTs scaffolds enhanced cell seeding efficiency and allowed for higher cell-cell interactions that supported the adhesion,proliferation,activity,morphology and subsequently improved the osteogenic differentiation of bone marrow mesenchymal stem cells in vitro.Together,this study elucidates that the construction of 3D printed-electrospun PCL/nHA/MWCNTs scaffolds provides an alternative strategy for the regeneration of subchondral bone and lays a foundation for subsequent in vivo studies.