3D bioprinted hyaluronic acid‑based cell‑laden scaffold for brain microenvironment simulation

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 years.Understanding 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 vitro.Here,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 models.The study provides experimental models for the exploration of the multiple factors in the brain microenvironment and scaffolds for GBM invasion study.

N/S co-doped 3D carbon framework prepared by a facile morphology-controlled solid-state pyrolysis method for oxygen reduction reaction in both acidic and alkaline media

Developing high-performance non-precious metal electrocatalysts for oxygen reduction reaction(ORR)is crucial for the commercialization of fuel cells and metal-air batteries.However,doped carbon-based materials only show good ORR activity in alkaline medium,and become less effective in acidic environment.We believe that an appropriate combination of both ionic and electronic transport path,and well dopant distribution of doped carbon-based materials would help to realize high ORR performance un-der both acidic and alkaline cond让ions.Accordingly,a nitrogen and sulfur co-doped carbon framework with hierarchical through-hole structure is fabricated by morphology-controlled solid-state pyrolysis of poly(aniline-co-2-ami no thiophenol)foam.The uniform high concentrations of nitrogen and sulfur,high intrinsic conductivity,and integrated three dimensional ionic and electronic transfer passageways of the 3D porous structure lead to synergistic effects in catalyzing ORR.As a result,the limiting current density of the carbonized poly(aniline-co-2-aminothiophenol)foam is equivalent to commercial Pt/C in acidic environment,and twice the latter in alkaline medium.

3D Printing of Polylactic Acid Bioplastic–Carbon Fibres and Twisted Kevlar Composites Through Coextrusion Using Fused Deposition Modeling

Polylactic acid(PLA)bioplastic is a common material used in Fused Deposition Modeling(FDM)3D printing.It is biodegradable and environmentally friendly biopolymer which made out of corn.However,it exhibits weak mechanical properties which reduced its usability as a functional prototype in a real-world application.In the present study,two PLA composites are created through coextruded with 3K carbon fibres and twisted Kevlar string(as core fibre)to form a fibre reinforced parts(FRP).The mechanical strength of printed parts was examined using ASTM D638 standard with a strain rate of 1 mm/min.It has been demonstrated that the FRPs coextruded with 3K carbon fibres had achieved significant improvement in Young’s modulus(+180.6%,9.205 GPa),ultimate tensile strength(+175.3%,103 MPa)and maximum tensile strain(+21.6%,1.833%).Although the Young’s modulus of Kevlar FRP was found to be similar to as compared to unreinforced PLA(~3.29 GPa),it has gained significant increment in terms of maximum tensile strain(+179.7%,104.64 MPa),and maximum tensile strain(+257%,5.384%).Thus,this study revealed two unique composite materials,in which the 3K carbon FRP can offer stiff and high strength structure while Kevlar FRP offers similar strength but at a higher elasticity.

3D printing of personalized polylactic acid scaffold laden with GelMA/autologous auricle cartilage to promote ear reconstruction

At present,the clinical reconstruction of the auricle usually adopts the strategy of taking autologous costal cartilage.This method has great trauma to patients,poor plasticity and inaccurate shaping.Three-dimensional(3D)printing technology has made a great breakthrough in the clinical application of orthopedic implants.This study explored the combination of 3D printing and tissue engineering to precisely reconstruct the auricle.First,a polylactic acid(PLA)polymer scaffold with a precisely customized patient appearance was fabricated,and then auricle cartilage fragments were loaded into the 3D-printed porous PLA scaffold to promote auricle reconstruction.In vitro,gelatin methacrylamide(GelMA)hydrogels loaded with different sizes of rabbit ear cartilage fragments were studied to assess the regenerative activity of various autologous cartilage fragments.In vivo,rat ear cartilage fragments were placed in an accurately designed porous PLA polymer ear scaffold to promote auricle reconstruction.The results indicated that the chondrocytes in the cartilage fragments could maintain the morphological phenotype in vitro.After three months of implantation observation,it was conducive to promoting the subsequent regeneration of cartilage in vivo.The autologous cartilage fragments combined with 3D printing technology show promising potential in auricle reconstruction.

Hydrothermal Synthesis and Crystal Structure of One 3D Coordination Polymer of Cobalt(II) Achieved from 1,1′-Biphenyl-2,2′,6,6′-tetracarboxylic Acid Ligand

A new three-dimensional coordination polymer {[Co（BPTC）0.5（bix）]′（H2O）}n （1, H4BPTC = 1,1′-biphenyl-2,2′,6,6′-tetracarboxylic acid, bix = 1,3-bis（imidazol-l-ylmethyl）-benzene） has been synthesized by the hydrothermal method and characterized by IR, elemental analysis, and single-crystal X-ray analysis. The crystal is of orthorhombic, space group Pbcn with a = 13.2975（10）, b = 13.8424（12）, c = 22.6367（17） A, CoC22H19N4Os, Mr = 478.34, V = 4166.7（6） A3, Dc = 1.525 g/cm^3, F（000） = 1968,μ = 0.867 mm^-1, S = 1.023 and Z = 8. The final R = 0.0683 and wR = 0.1529 for 3655 observed reflections with I 〉 20（I）. In the title complex, the 2D Co-BPTC layer is formed through self-assembly of Co（II） ions and bridging BPTC4-ligands in a molar ratio of 2：1. The metal-organic lattice layers are further united together through the second bridging ligand bix to form a 3D metal-organic framework. The thermal stability of the title complex was studied by thermal gravimetric （TG） and differential thermal analysis （DTA）.

Enhanced production of glycyrrhetic acid 3-O-mono-β-D-glucuronide by fed-batch fermentation using p H and dissolved oxygen as feedback parameters

Glycyrrhetic acid 3-O-mono-β-D-glucuronide （GAMG）, the major functional ingredient in licorice, has widespread applications in food, pharmacy and cosmetics industry. The production of GAMG through Penicillium purpurogenum Li-3 cultivation was for the first time performed through both batch and fed-batch processes in bioreactors. In batch process, under optimal conditions （pH 5.0, temperature 32℃, agitation speed 100 r. rain 1）, 3.55 g. L^-1 GAMG was obtained in a 2.5 L fermentor. To further enhance GAMG production, a fine fed-batch process was developed by using pH and DO as feedback parameters. Starting from 48 h, 100 m190 g-L 1 substrate Glycyrrhizin （GL） was fed each time when pH increased to above 5.0 and DO was increased to above 80%. This strategy can significantly enhance GAMG production： the achieved GL conversion was 95.34% with GAMG yield of 95.15%, and GAMG concentration was 16.62 g. L^-1 which was 5 times higher than that of batch. Then, a two-step separation strat- egy was established to separate GAMG from fermentation broth by crude extraction of 15 ml column packed with D10I resin followed by fine purification with preparative C18 chromatography. The obtained GAMG purity was 95.79%. This study provides a new insight into the industrial bioprocess of high-level GAMG production.

Effects of Selected Printing Parameters on the Fire Properties of 3D-Printed Neat Polylactic Acid(PLA)and Wood/PLA Composites

The effects of selected printing parameters on the fire properties of additively produced composites from neat polylactic acid(PLA)and wood/PLA filaments were investigated.The reaction to fire of the 3D-printed specimens was tested according to the ISO 5660-1 cone calorimeter test method.The results showed that the properties of the specimens when exposed to fire were significantly affected by the incorporation of wood flour into the PLA filament.It was also interesting that PLA specimens had much better reactions to fire than the wood/PLA specimens.Time to ignition was found to be much longer in the 3D-printed PLA specimens.Although the maximal heat release rate was a little higher in the PLA than the wood/PLA specimens,the duration of HRR was longer for the wood/PLA specimens.The initial mass of the specimens was smaller in the wood/PLA composites,but during the radiant heat exposure the mass typically decreased slower than in the PLA specimens.

3D printed lactic acid bacteria hydrogel:cell release kinetics and stability

In this study,a new type of 3 D printed living biological hydrogel was developed by integrating lactic acid bacteria(LAB)into biocompatible and non-toxic polymer materials.Interestingly,the living materials loaded with LAB can be freeze-dried and reused for more than 100 times.The bio-hydrogel can be used to co-culture different LAB and keep its fermentation performance stable in long-term use.The release kinetics model and response surface method were used to simulate and optimize the bacteria release mode in the bio-hydrogel.The results show that the release of bacteria from hydrogel is regulated by the coupling of Fickian diffusion and polymer swelling.The stability of LAB hydrogel was evaluated by reuse experiments.The images of confocal microscopy and scanning electron microscope showed that the bacteria with high cell viability were distributed in the hydrogel and intact structure of the living hydrogel was maintained after 100 times of reuse as yoghurt starter.In conclusion,the 3 D printed LAB bio-hydrogel developed in this study has the advantage of reuse and sustainability,which is expected to open up a new way for the preparation of food culture starter.

A Novel Three-dimensional Mn(Ⅱ) Coordination Polymer Constructed from Biphenyl-3,3',5,5'-tetracarboxylic Acid and Water

The title Mn（Ⅱ） coordination polymer,poly{[heptaaqua-（μ4-bi-phenyl-3,3？,5,5？-tetracarboxylate）-bimanganese（Ⅱ）] pentahydrate},[Mn_2（bpta）（H_2O）_7]_n·5n H_2O（I）,is crystallized from a mixture of biphenyl-3,3？,5,5？-tetracarboxylic acid（H_4bpta） and MnCl_2·4H_2O in waterethanol under room temperature. Its asymmetric unit consists of one and two halves of crystallographically independent Mn（Ⅱ） cations,one fully deprotonated H4 bpta ligand,seven coordinated water molecules and five solvent water as guest molecules. In I,each Mn（Ⅱ） atom is octahedrally coordinated by six oxygen atoms from bpta^（4-） anions and coordinated water molecules. In the Mn（Ⅱ） cations,one half Mn（Ⅱ） ion of them located at a 2-fold axis generating a trinuclear [Mn_3（H_2O）_2（RCOO）_2] linker by μ1,1-O（water） and μ1,3-O,O？（carboxylate） bridges and another half Mn（Ⅱ） ion with an inversion is a mononuclear linker. These neighbouring trinuclear and mononuclear Mn（Ⅱ） cations are linked together by biphenyl-3,3？,5,5？-tetracarboxylates to form a three-dimensional framework with a（42.84） topology of a（4,4）-connected net,in which the positions of the trinuclear [Mn_3（H_2O）_2（R-COO）_2] linker as a 4-connector linking four bpta^（4-） ligands in I reproduce an eagle-shaped arrangement. The polymeric structure exhibits a water channel with an accessible void of 797.1 ？~3,amounting to 15.7% of the total unit-cell volume. Each of the cavities in the network is occupied by solvent water molecules.

The calmodulin-dependent protein kinase II inhibitor KN-93 protects rat cerebral cortical neurons from N-methyl-D-aspartic acid-induced injury

In this study, primary cultured cerebral cortical neurons of Sprague-Dawley neonatal rats were treated with 0.25, 0.5, and 1.0 μM calmodulin-dependent protein kinase II inhibitor KN-93 after 50 μM N-methyI-D-aspartic acid-induced injury. Results showed that, compared with N-methyi-D- aspartic acid-induced injury neurons, the activity of cells markedly increased, apoptosis was significantly reduced, leakage of lactate dehydrogenase decreased, and intracellular Ca2＋ concentrations in neurons reduced after KN-93 treatment. The expression of caspase-3, phosphorylated calmodulin-dependent protein kinase II and total calmodulin-dependent protein kinase II protein decreased after KN-93 treatment. And the effect was apparent at a dose of 1.0 pM KN-93. Experimental findings suggest that KN-93 can induce a dose-dependent neuroprotective effect, and that the underlying mechanism may be related to the down-regulation of caspase-3 and calmodulin- dependent protein kinase II expression.

Preparation and Spectroscopic of Vanadyl（Ⅱ） Vitamin D3 Amino Acid Mixed Complexes as Insulin Mimetic Drug

A new six intraperitoneal injection insulin-mimetic vanadyl(Ⅱ) compounds [(VD3^-1)(VO^+2)(AAn^-1)](where(n=1~6);AA1=isoleucine, AA2=threonine, AA3=proline, AA4=phenylalanine, AA5=lysine and AA6=glutamine) were synthesized by the chemical reactions between vitamin D3(VD3), VOSO4 and amino acids(AAn) with equal molar ratio 1∶1∶1 in neutralized media. The structures of these complexes were elucidated by spectroscopic methods like, infrared and solid reflectance spectroscopes. Magnetic moments and electronic spectra reveal square pyramid geometrical structure of the complexes. The infrared spectra assignments of these complexes revealed that the chelation towards vanadyl(Ⅳ) ions existed via deprotonation of the hydroxyl group of VD3 drug ligand and so amino acids act as bidentate ligand via N-amino and O-carboxylate groups. The anti-diabetic efficiency of these complexes were evaluated against streptozotocin induced diabetic male albino rats.

CHBMISTRY OF HYODEOXYCHOLIC ACID 5. CONCISE SYNTHESIS OF 25-HYDROXYCHOLESTEROL FROM HYODEOXYCHOLIC ACID, A KEY INTERMEDIATE OF 25-HYDROXYVITAMIN D_3

25-Hydroxycholesterol, which is an important intermediate for the synthesis of 25-hvdroxyvitamin D_3 and 1α, 25-dihydroxyvitamin D_3, was prepared efficiently from hyodeoxycholic acid in 31% overall yield in seven steps.

啤酒酵母中(1→3)-β-D-葡聚糖的提取及其机理研究

分别采用酸法、酸碱法来提取啤酒酵母中的(1→3) β D 葡聚糖,然后对其产品进行多糖成分和紫外光谱分析。结果发现,在用c(CH3COOH)=0 5mol/L的水溶液提取啤酒酵母中的(1→3) β D 葡聚糖时,其产品中除含有葡聚糖外,还含有一定量的甘露聚糖和蛋白质这两种成分。但先用c(NaOH)=1 0mol/L的水溶液提取,再用w(CH3COOH)=4%的醋酸溶液处理时,产品为高纯度的(1→3) β D 葡聚糖。此结论由傅立叶红外光谱和核磁共振碳谱得到进一步的证实。接着从其水解机理上阐述了产生上述两种不同结果的原因,从而说明了酸碱法是从啤酒酵母中提取(1→3) β D 葡聚糖的理想途径。

维生素D联合ω-3脂肪酸治疗儿童孤独症的疗效

目的:观察服用维生素D(VD)联合ω-3脂肪酸治疗孤独症(autism spectrum disorder,ASD)患儿的疗效。方法:本研究为48名年龄在5～12岁、新诊断的ASD患儿参与的随机双盲临床试验。患儿分成4组,每组12例。对照组患儿服用安慰剂,VD组患儿服用VD 800U/d,ω-3脂肪酸组患儿服用ω-3脂肪酸900mg/d,联合用药组患儿联合服用VD 800U/d及ω-3脂肪酸900mg/d。用药同时所有患儿针对症状进行结构化训练,地点为医院,时间为4h/d,每周5d。在用药12个月后采用儿童孤独症评定量表(Childhood Autism Rating Scale,CARS)评估治疗后的临床症状改善情况。结果:治疗12个月后,与对照组比较,VD组及联合用药组患儿大部分CARS评分明显降低(P<0.05)。联合用药组患儿视觉反应及听觉反应评分较VD组下降更明显(P<0.05),且联合用药组焦虑反应评分较ω-3脂肪酸组下降更明显(P<0.05)。结论:在结构化训练的同时补充VD或VD联合ω-3脂肪酸可有效改善ASD患儿的症状。VD联合ω-3脂肪酸有望成为治疗儿童ASD的有效辅助方法。

3,5-二硝基水杨酸(DNS)法测定D-半乳糖醛酸含量的条件探索

[目的]优化3,5-二硝基水杨酸（DNS）法用于测定D-半乳糖醛酸含量的条件。[方法]通过单因素实验研究了3,5-二硝基水杨酸（DNS）法测定D-半乳糖醛酸含量的测定条件。[结果]单因素试实结果表明,利用3,5-二硝基水杨酸法测定D-半乳糖醛酸含量的优化条件为：测定波长540 nm,DNS用量4.0 ml,反应温度100℃,反应时间5 min,最佳测定时间60 min内。此条件下回归方程y=1.0226x-0.2784,回归系数r=0.9997,平均回收率99.96%,D-半乳糖醛酸含量测定范围0.5-1.1 mg/ml,统计分析表明,该方程显著存在。[结论]多次实验验证,该方法测定D-半乳糖醛酸含量时操作简单、准确度高、重复性好。

花旗松素和3,3'-二甲氧基鞣花酸-4-O-β-D-吡喃葡萄糖苷对肿瘤细胞的增殖抑制作用

目的探讨从红蓼成熟果实中分离出来的花旗松素和3,3'-二甲氧基鞣花酸-4-O-β-D-吡喃葡萄糖苷对人体肿瘤细胞的增殖抑制作用。方法用结晶紫染色法检测花旗松素和3,3'-二甲氧基鞣花酸-4-O-β-D-吡喃葡萄糖苷对人胃癌MGC细胞、人肝癌HepG-2细胞和人盲肠癌Hce-8693细胞的增殖抑制作用。结果花旗松素和3,3'-二甲氧基鞣花酸-4-O-β-D-吡喃葡萄糖苷在1～500μg/mL质量浓度范围内对MGC细胞、HepG-2细胞和Hce-8693细胞均有一定的生长抑制作用,随着剂量的增大和作用时间的延长,呈较好的剂量-时间-效应关系;同等条件下,花旗松素比3,3'-二甲氧基鞣花酸-4-O-β-D-吡喃葡萄糖苷的抑制作用强。结论花旗松素与3,3'-二甲氧基鞣花酸-4-O-β-D-吡喃葡萄糖苷均有体外抗肿瘤活性,能抑制MGC细胞、HepG-2细胞和Hce-8693细胞的增殖。

全反式维甲酸和1,25-二羟维生素D_3联合应用对大肠癌细胞的分化诱导作用

目的 : 观察联合使用全反式维甲酸 (all trans retinoicacid ,ATRA)和 1,2 5 二羟维生素D3 对大肠癌细胞株LoVo的影响。方法 :以MTT法测定细胞生长 ,碱性磷酸酶 (alkalinephosphatases ,ALP)比活性检测细胞分化。结果 :ATAR和 1,2 5 二羟维生素D3 对LoVo生长的抑制作用在一定浓度范围内呈时间浓度依赖关系 ,联合用药时抑制作用增强。经药物作用细胞后肠型ALP逐渐升高。结论 :联合使用ATRA和 1,2 5 二羟维生素D3

从酵母细胞壁提取β-1,3-D-葡聚糖的研究

分别采用酸法、碱法来提取酵母细胞壁中的β-1,3-D-葡聚糖。用紫外光谱法、纸层析法法和红外光谱法分析多糖成分。结果发现:经酸法(醋酸溶液浓度为0.5mol/L)提取的β-1,3-D-葡聚糖产品中除含有葡聚糖外,还含有一定量的甘露聚糖和蛋白质成分;而用碱法(氢氧化钠溶液浓度为1.0mol/L)提取时,产品为高纯度的β-1,3-D-葡聚糖。本文从其水解机理上探讨了产生上述两种不同结果的原因,指出碱法提取是从酵母中提取β-1,3-D-葡聚糖的高效方法。

应用抑制性消减杂交分析全反式维甲酸和1,25-二羟维生素D_3诱导结肠癌细胞的相关基因

为探讨结肠癌细胞诱导分化的机制 ,采用抑制性消减杂交 (suppression subtractivehybridization,SSH)研究联合使用全反式维甲酸和 1 ,2 5-二羟维生素 D3诱导分化结肠癌 Lo Vo细胞前、后差异表达的基因 .经比较消减 c DNA文库的序列与基因库的序列 ,发现 :有 1个基因的序列与正常鳞状上皮细胞中的 1个表达序列标签 (expressed sequence tag,EST)高度同源 ,同时发现6个新 EST (基因库登录号为 AW2 66492、AW2 66493、AW2 66494、AW58751 8、AW58751 9和AW58752 0 ) .说明诱导分化涉及到多个基因的表达 ,结肠癌的发生是多基因综合作用的结果 .进一步研究这些基因和 EST的功能对于结肠癌的防治将有重要意义 .

d,l-2-乙酰氨基-3-(3′-吲哚)丙酸的制备和拆分研究

以3-吲哚基-甲基-乙酰氨基丙二酸二乙酯为原料，经选择性水解制备d，l-2-乙酰氨基-3-（3＇-吲哚）丙酸，最佳反应条件是：反应温度70～80℃，反应时间为6h，物料3-吲哚基-甲基-乙酰氨基丙二酸二乙酯与氢氧化钠的摩尔比为1：2.5，产率可达到84.4％ 研究了利用对硝基苯基-2-氨基-1，3-丙二醇为拆分剂对d，l-2-乙酰氨基-3-（3＇-吲哚）丙酸进行拆分，d-2-乙酰氨基-3-（3＇-吲哚）丙酸的拆分纯度为98％。