One-step cell biomanufacturing platform:porous gelatin microcarrier beads promote human embryonic stem cell-derived midbrain dopaminergic progenitor cell differentiation in vitro and survival after transplantation in vivo

Numerous studies have shown that cell replacement therapy can replenish lost cells and rebuild neural circuitry in animal models of Parkinson’s disease.Transplantation of midbrain dopaminergic progenitor cells is a promising treatment for Parkinson’s disease.However,transplanted cells can be injured by mechanical damage during handling and by changes in the transplantation niche.Here,we developed a one-step biomanufacturing platform that uses small-aperture gelatin microcarriers to produce beads carrying midbrain dopaminergic progenitor cells.These beads allow midbrain dopaminergic progenitor cell differentiation and cryopreservation without digestion,effectively maintaining axonal integrity in vitro.Importantly,midbrain dopaminergic progenitor cell bead grafts showed increased survival and only mild immunoreactivity in vivo compared with suspended midbrain dopaminergic progenitor cell grafts.Overall,our findings show that these midbrain dopaminergic progenitor cell beads enhance the effectiveness of neuronal cell transplantation.

Bio-inspired Hydroxyapatite/Gelatin Transparent Nanocomposites

Hydroxyapatite(HA)nanoparticles impart outstanding mechanical properties to organicinorganic nanocomposites in bone.Inspired by the composite structure of HA nanoparticles and collagen in bone,a high performance HA/gelatin nanocomposite was first developed.The nanocomposites have much better mechanical properties(elongation at break 29.9%,tensile strength 90.7 MPa,Young’s modulus 5.24 GPa)than pure gelatin films(elongation at break 9.3%,tensile strength 90.8 MPa,Young’s modulus 2.5 GPa).In addition,the composite films keep a high transmittance in visible wavelength range from 0%to 60%of the HA solid content.These differences in properties are attributed to the homogeneous distribution of HA nanoparticles in the gelatin polymer matrix and the strong interaction between the particle surfaces and the gelatin molecules.This protocol should be promising for HA-based nanocomposites with enhanced mechanical properties for biomedical applications.

Three-dimensional porous bimetallic metal–organic framework/gelatin aerogels: A readily recyclable peroxymonosulfate activator for efficient and continuous organic dye removal

As promising catalysts for the degradation of organic pollutants,metal–organic frameworks(MOFs)often face limitations due to the particle agglomeration and challenging recovery in liquid-catalysis application,stemming from their powdery nature.Engineering macroscopic structures from pulverous MOF is thus of great importance for broadening their practical applications.In this study,three-dimensional porous MOF aerogel catalysts were successfully fabricated for degrading organic dyes by activating peroxymonosulfate(PMS).MOF/gelatin aerogel(MOF/GA)catalysts were prepared by directly integrating bimetallic FeCo-BDC with gelatin solutions,followed by freeze-drying and low-temperature calcination.The FeCo-BDC-0.15/GA/PMS system exhibited remarkable performance in degrading various organic dyes,eliminating 99.2%of rhodamine B within a mere 5 min.Compared to the GA/PMS system,there was over a 300-fold increase in the reaction rate constant.Remarkably,high removal efficiency was maintained across varying conditions,including different solution pH,co-existing inorganic anions,and natural water matrices.Radical trapping experiments and electron paramagnetic resonance analysis revealed that the degradation involved radical(SO_(4)^(-)·)and non-radical routes(^(1)O_(2)),of which ^(1)O_(2) was dominant.Furthermore,even after a continuous 400-min reaction in a fixed-bed reactor at a liquid hourly space velocity of 27 h^(-1),the FeCo-BDC/GA composite sustained a degradation efficiency exceeding 98.7%.This work presents highly active MOF-gelatin aerogels for dye degradation and expands the potential for their large-scale,continuous treatment application in organic dye wastewater management.

Dynamic response of armor-piercing bullets to blunt and penetration with protective gelatin

To investigate the coupled damage mechanism of blunt impact and bullets penetration after penetrating ballistic plates against human body targets,experiments were conducted using 6.8 mm caliber armor-piercing bullets against gelatin targets with protective coatings.A numerical analysis model was developed to simulate bullet penetration into gelatin with protective coatings,obtaining endpoint characteristic quantities such as bullet velocity changes,changes in energy distribution,pressure,stress,and stress wave variations within the gelatin target after protection.The results indicate that at a velocity of 640 m·s^(-1),the 6.8 mm caliber armor-piercing round failed to penetrate the ballistic plate yet still caused a blunt impact depression of 37 mm in depth.Under conditions where the bullet did not penetrate the ballistic plate,approximately 80%of the bullet's kinetic energy was absorbed by the ballistic plate.At a velocity of 740 m·s^(-1),the bullet penetrated the ballistic plate,resulting in a blunt impact depression depth of 56 mm and an instantaneous cavity with a maximum diameter of 60 mm.During the process of penetrating the ballistic plate,approximately 50%of the bullet's kinetic energy was absorbed by the ballistic plate,and about 40%of the remaining kinetic energy transferred into the gelatin during the penetration of the target.

Constructing a biofunctionalized 3D-printed gelatin/sodium alginate/chitosan tri-polymer complex scaffold with improvised biological andmechanical properties for bone-tissue engineering

Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of this type of scaffold to make it a potential template for bone-tissue regeneration.We experimented with adding 0%–15%(volume fraction)gelatin(GE),a protein-based biopolymer known to promote cell adhesion,proliferation,and differentiation.The resulting tri-polymer complex was used as bioink to fabricate SA/CH/GEmatrices by three-dimensional(3D)printing.Morphological studies using scanning electron microscopy revealed the microfibrous porous architecture of all the structures,which had a pore size range of 383–419μm.X-ray diffraction and Fourier-transform infrared spectroscopy analyses revealed the amorphous nature of the scaffold and the strong electrostatic interactions among the functional groups of the polymers,thereby forming polyelectrolyte complexes which were found to improve mechanical properties and structural stability.The scaffolds exhibited a desirable degradation rate,controlled swelling,and hydrophilic characteristics which are favorable for bone-tissue engineering.The tensile strength improved from(386±15)to(693±15)kPa due to the increased stiffness of SA/CH scaffolds upon addition of gelatin.The enhanced protein adsorption and in vitro bioactivity(forming an apatite layer)confirmed the ability of the SA/CH/GE scaffold to offer higher cellular adhesion and a bone-like environment to cells during the process of tissue regeneration.In vitro biological evaluation including the MTT assay,confocal microscopy analysis,and alizarin red S assay showed a significant increase in cell attachment,cell viability,and cell proliferation,which further improved biomineralization over the scaffold surface.In addition,SA/CH containing 15%gelatin designated as SA/CH/GE15 showed superior performance to the other fabricated 3D structures,demonstrating its potential for use in bone-tissue engineering.

Fish Gelatin-Based Film Containing Maillard Reaction Products:Properties and Its Use as Bag for Packing Chicken Skin Oil

Maillard reaction is a non-enzymatic browning reaction and its products(MRPs)have been proven to possess antioxidant properties.This research aimed to produce a fish gelatin-based packaging incorporated with MRPs to retard lipid oxidation in chicken skin oil(CSO)during storage at ambient temperature(28℃–30℃).MRPs produced from fish gelatin and fructose(1:1,90℃,pH 11)showed the highest antioxidant properties compared to those prepared under other conditions.Different glycerol/MRPs ratios(30:0,25:5,20:10,15:15,10:20,5:25,0:30)were incorporated into the film and resulting films were characterized.Glycerol/MRPs at 10:20 ratio was chosen to add into the film prior to bag preparation via heat sealing method.CSO packed in the bag was monitored for lipid hydrolysis and oxidation during 15 days of storage(30℃±0.5℃,RH 52%±5%).After 15 days,quality deterioration was lower in CSO packed in the prepared gelatin bag as evidenced by lower FFA,TBARS,and volatile compounds in comparison with CSO packed in LDPE bag.Fish gelatin film added with MRPs possessed an excellent water vapor barrier property(WV-BP).This finding indicated that MRPs could be used to substitute glycerol and simultaneously could serve as antioxidants for the developed active bag.The novel packaging can be a potential alternative packaging for retarding lipid oxidation of lipid or fatty foods.

Studies of XRD and FTIR on Synthesized Novel Hybrid Thin Film Made of Hydroxyapatite, Poly Vinyl Alcohol and Gelatin for Biomedical Application

With the modern advancement of treatment approaches in medical science, the application of biomaterials in tissue engineering provides a remarkable opportunity to overcome graft rejection as well as proper wound healing. In this study, novel hybrid films have been synthesized by incorporation of polyvinyl alcohol (PVA), gelatin, and gelatin with glycerin along with different concentrations of pre-prepared hydroxyapatite (HAP) by solution casting method at room temperature in a biosafety cabinet. Glutaraldehyde has been added as a crosslinker in this whole procedure. Fourier-transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD) have been conducted to observe and compare the structural and chemical stability of the synthesized hybrid film properties. The FTIR results and X-Ray Diffraction analyses confirmed the chemical interactions between HAP, PVA, gelatin, and glycerin have occurred. The crystallinity of HAP also remains in all the prepared hybrid film samples that are observed in XRD. It is expected that these newly synthesized hybrid films could be a better opportunity for various sectors of tissue engineering such as skin, bone, tendon, and cartilage. These synthesized hybrid films can be suitable for wound healing covering. These studies could be a new scope for long-term drug delivery directly on wound sites in diabetic gangrene foot or burn patients as well as cartilage or joint replacement therapy.

Development and Characterization of Hybrid Film Made of Hydroxyapatite, Poly Vinyl Alcohol and Gelatin for Biomedical Application

In the recent research field of bone tissue engineering, polymeric materials play an implacable role in mimes the natural behavior of hard and soft tissues. In some medical conditions such as diabetics, osteoarthritis, burns, or joint replacement conditions, this polymeric materials implication enhances the internal mechanical activities which result in the early recovery of disease by facilitating the wound healing process. In this study, hybrid films have been synthesized based on polyvinyl alcohol (PVA), gelatin, and gelatin with glycerin incorporated with different concentrations of pre-prepared hydroxyapatite (HAP) by solution casting method at room temperature in biosafety cabinet. Glutaraldehyde has been added as a crosslinker in this whole procedure. The mechanical property, swelling, and porosity percentage have been conducted to characterize the structural stability of the synthesized hybrid films. Porosity and swelling of samples are also represented by proper biocompatibility (>90% porosity and swelling in DDW and PBF vary between 287%~72%). Tensile strength (TS), E modulus (Young’s modulus), Elongation at maximum, and Elongation at break are observed to perceive the mechanical properties of hybrid film samples, which are compatible with mechanical properties of different tissue such as trabecular bone, articular cartilage, tendon, nerve and skin tissue. Though, biocompatibility tests both in vivo and in vitro are essential for clinical application in the future. However, the experiment carried out till now explains the true possibility of newly synthesized hybrid films for long-term drug delivery directly on wound sites for wound healing and burn dressing patients in head-neck surgery reconstruction, diabetic gangrene foot, as well as cartilage or joint replacement therapy.

Tissue Regeneration in Infected Wounds of Albino Rats Using Ciprofloxacin-Loaded Gelatin Microspheres Incorporated Collagen Scaffold: A Histological Approach with H&E Staining

A wound care system consisting of ciprofloxacin-loaded gelatin microspheres impregnated in a macroporous collagen scaffold was created to effectively control wound infection and regenerate soft tissue at the wound site.Histological and biochemical alterations were observed in infected wounds treated with these scaffolds in Albino Wistar rats.Furthermore,the study examined the immediate and prolonged release of ciprofloxacin from the scaffolds,as well as their function in eliminating bacterial infections and expediting the process of skin healing and regeneration.The developed technique was followed in the streamlined process of creating these collagen scaffolds.Compared to untreated wounds,the group receiving scaffold treatment experienced a faster rate of wound closure.It was noted that the rate of infections was considerably reduced and that full soft tissue regeneration occurred within 12 days.The development of well-deposited collagen bundles in the treated groups was demonstrated by H&E staining,which verified the flawless regeneration of the dermis and epidermis.The antimicrobial agent-loaded gelatin microspheres impregnated into the porous collagen scaffold demonstrated remarkable soft tissue regeneration and efficient infection control at the wound site.

BaTiO3/gelatin核壳复合粒子的制备及电场响应性能研究

为了提高BaTiO3颗粒在含水弹性体中的电场响应能力,以粒径约为500nm的单分散球型Ba-TiO3颗粒为基础,采用微乳液法成功制备了BaTiO3为核、明胶(gelatin)为壳的BaTiO3/gelatin核壳复合粒子。利用TEM、XRD、FT-IR、TG和光学接触角测量等手段对粒子的组成、结构及表面亲水性能进行了表征和测量。结果表明,在立方相BaTiO3核的表面均匀包覆了1层约40～50nm的gelatin,Gelatin壳层约占粒子总重的4.0%,且粒子表面保持良好的亲水性。将粒子分散到含水胶体体系中,通过测量在无/有电场作用下胶凝得到的含水弹性体的储能模量考察了粒子在此体系中的电场响应性能,发现BaTiO3/gelat-in复合粒子在明胶(或壳聚糖)水凝胶弹性体中的电场响应性能均明显强于纯BaTiO3粒子,而且在明胶水凝胶中的响应性能更强。结果说明,聚合物包覆能够明显提高BaTiO3粒子的电场响应性能,而且粒子表面与分散体系相容性越高,粒子的响应性能越好。

青海、西藏主栽青稞品种营养品质及其淀粉糊化特性

青稞是开发营养健康食品的优质原料,为研究品种、产地等因素对青稞营养品质和加工特性的影响,本文收集我国青稞主产区青海和西藏的30个主栽品种,比较主要营养成分及其淀粉糊化特性差异。结果表明:不同青稞营养成分差异较大,重要功能因子β-葡聚糖、阿拉伯木聚糖(arabinoxylan,AX)、总酚介于3.74%~6.54%、5.63%~11.51%和1.90~4.24 mg/g;同时发现青稞β-葡聚糖含量与总酚含量呈极显著负相关(P<0.01)。品种亦显著影响淀粉糊化特性(P<0.05),样品间淀粉峰值黏度介于468.67~4844.67 cP,糊化温度介于66.30~86.85℃。主成分分析将营养成分、糊化性质共15个指标降维得到5个主成分,发现糊化性质及非淀粉多糖、AX、淀粉、β-葡聚糖含量在青稞品质评价中具有重要作用。经聚类分析,筛选出12个高β-葡聚糖(5.62%~6.54%)、11个高AX(10.37%~11.51%)、1个高总酚(4.24 mg/g)、10个高糊化温度(81.05~86.85℃)青稞品种。西宁柴青1号兼具高β-葡聚糖、高AX、高糊化温度的特点,同时总酚含量适中,可能在高活性、低升糖指数(GI)青稞功能食品开发领域具有优势。

Extraction Characteristics of Anthocyanins from Preliminarily-processed Products of Purple Sweet Potatoes during the Gelatinization Process

Objective] This study aimed to investigate the method for efficient utilization and development of purple sweet potatoes. [Method] Purple sweet potatoes were dried at two specific temperatures and prepared into preliminarily-processed products for gelatinization simulation to analyze the extraction amount of anthocyanins from gelatinized samples at different gelatinization stages. [Result] During the gelatinization process, the extraction rate of anthocyanins from purple sweet potato samples reached the highest as the temperature rised from 90 ℃ to 95 ℃,and the extraction amount of anthocyanins reached the maximum at 15 min postheat preservation at 95 ℃. Purple sweet potato samples dried at 60 ℃ exhibited larger retention amount, larger maximum extraction amount and higher maximum extraction rate of anthocyanins compared with those dried at 110 ℃. [Conclusion] Drying at low temperatures and appropriately shortening the initial gelatinization stage below 90 ℃ is conducive to the retention and extraction of anthocyanins from purple sweet potatoes.

不同静电纺丝膜上骨髓间充质干细胞的黏附、增殖与成血管平滑肌分化

背景:临床上迫切需要小口径人工血管来治疗冠状动脉和外周动脉疾病,目前,血管组织工程已成为制备小口径人工血管的主要方法,选择合适的生物材料和细胞来源是小口径组织工程血管构建成功的关键因素。目的:观察4种静电纺丝膜材料对骨髓间充质干细胞增殖、黏附及分化为血管平滑肌细胞的影响。方法:分离提取SD大鼠骨髓间充质干细胞。将骨髓间充质干细胞分别接种于聚己内酯(PCL)、聚己内酯-透明质酸(PCL-HA)、聚己内酯-丝素蛋白(PCL-SF)、聚己内酯-明胶(PCL-GEL)静电纺丝膜材料上,培养1,3,7 d后,扫描电镜下观察材料上的细胞排布,鬼笔环肽染色观察材料上的细胞增殖与黏附,qRT-PCR检测材料上细胞分泌的CD90、Meflin、转化生长因子βmRNA表达;向血管平滑肌细胞诱导分化7 d后,qRT-PCR检测材料上细胞ɑ-平滑肌肌动蛋白mRNA表达。结果与结论:①扫描电镜下可见骨髓间充质干细胞在4种静电纺丝膜上均沿着静电纺丝膜的纤维走向排列;②鬼笔环肽染色显示,骨髓间充质干细胞在4种静电纺丝膜上分布规律,均沿着纤维走向呈现平行分布,并且PCL-HA、PCL-SF、PCL-GEL静电纺丝膜较PCL静电纺丝膜更有利于骨髓间充质干细胞的增殖、黏附,PCL-SF静电纺丝膜相较于PCL-HA、PCL-GEL静电纺丝膜更有利于骨髓间充质干细胞的增殖、黏附;③qRT-PCR检测显示,4种静电纺丝膜材料均可维持骨髓间充质干细胞CD90和Meflin的mRNA表达,组间比较差异无显著性意义(P>0.05);PCL-HA、PCL-SF、PCL-GEL组培养1,7 d的转化生长因子βmRNA表达高于PCL组(P<0.05),PCL-SF组培养3,7 d的转化生长因子βmRNA表达高于其他3组(P<0.05),PCL-HA组培养7 d的转化生长因子βmRNA表达高于PCL-GEL组(P<0.05);④qRT-PCR检测显示,PCL-SF组ɑ-平滑肌肌动蛋白mRNA表达高于其他3组(P<0.05),PCL-HA组ɑ-平滑肌肌动蛋白mRNA表达高于PCL组(P<0.05);⑤结果表明:相较于PCL、PCL-HA、PCL-GEL静电纺丝膜,PCL-SF静电纺丝膜与骨髓间充质干细胞结合更适合制备小口径组织工程血管。

富血小板纤维蛋白复合甲基丙烯酰化明胶水凝胶的促成骨性能

背景:富血小板纤维蛋白具有制备简单、制作费用低、安全性高等诸多优势,目前已被广泛应用于口腔颌面外科骨缺损修复研究中,但存在降解速度太快、生长因子释放时间短等问题。目的:将富血小板纤维蛋白负载于甲基丙烯酰化明胶水凝胶内,通过体内外实验分析其促成骨性能。方法:①抽取新西兰大白兔静脉血,制备富血小板纤维蛋白。分别制备含0,0.05,0.075,0.1 g富血小板纤维蛋白的甲基丙烯酰化明胶水凝胶,分别记为GelMA、GelMA/PRF-0.05、GelMA/PRF-0.075、GelMA/PRF-0.1,表征水凝胶的微观形貌与体外缓释性能。②将4种水凝胶分别与MC3T3-E1细胞共培养,以单独培养的细胞为对照,检测细胞增殖活性;成骨诱导后,检测细胞碱性磷酸酶活性、矿化能力、成骨相关基因(骨钙素、骨桥蛋白、RUNX2)mRNA与蛋白表达,ERK1/2-p38 MAPK通路蛋白mRNA与蛋白表达。③取15只新西兰大白兔。在每只兔颅骨部分别制备4个直径8 mm的全层骨缺损,其中1处缺损不植入任何材料(空白对照组),另3处缺损分别植入GelMA水凝胶、富血小板纤维蛋白、GelMA/PRF-0.1水凝胶。术后4,8,12周,进行骨缺损部位Micro-CT扫描与骨组织形态观察。结果与结论:①扫描电镜下可见4组水凝胶都具有蜂窝状的孔隙结构,并且随着水凝胶中富血小板纤维蛋白含量的增加,水凝胶的孔径轻微减小,但组间比较无明显差异;3组GelMA/PRF水凝胶均能以一定的速率释放转化生长因子β1与胰岛素样生长因子1,随着时间的延长,转化生长因子β1与胰岛素样生长因子1累计释放量显著增加。②CCK-8检测与活/死染色显示,3组GelMA/PRF水凝胶可促进MC3T3-E1细胞的增殖;碱性磷酸酶染色、茜素红染色及成骨基因检测结果显示,GelMA/PRF水凝胶可促进MC3T3-E1细胞的成骨分化,同时可抑制ERK1/2-p38 MAPK通路蛋白的表达,并且呈现富血小板纤维蛋白含量依赖性。③Micro-CT扫描显示,GelMA/PRF-0.1水凝胶组兔骨缺损处骨矿物质密度与骨体积分数均高于其他3组(P<0.05);苏木精-伊红染色显示,相较于其他3组,GelMA/PRF-0.1水凝胶组兔骨缺损处新骨形成更快、更成熟。④结果表明,GelMA/PRF水凝胶在体内外均具有良好的促成骨性能,该作用可能与抑制ERK1/2-p38 MAPK通路蛋白表达有关。

Studies on Adriamycin Magnetic Gelatin Microspheres

The preparation and properties of adriamycin magnetic gelatin microspheres(Adr- MG-ms)were reported.The synthesis of magnetic iron oxide ultrafine particle and embolization effects of magnetic gelatin microspheres(MG-ms)in dog were studied.Adr- MG-ms consist of 2%(w/w)of adriamycin(Adr)as the core,and 68% of gelatin and 30% of magnetite as the shell with a mean particle size of 22 μm. In vitro experiment,the release rate of drug demonstrated that the microspheres have sustained-release properties.The average diameter of magnetic iron oxide was approximately l0 nm. Transcatheter embolization with MG-ms and ￣(99m)Tc-labelled MG-ms was performed under external magenet control in dog liver,respectively.Gamma photography and angiogram revealed that MG-ms level was almost equal both in left and right hepatic arteries without magnet,while with magnet(1200 Gs),MG-ms level in left hepatic artery(target site)was about 2.25 fold higher than in right hepatic artery,and few MG-ms in thyroid gland,brain and heart was observed.Results showed that the MG-ms is a promising embolic agent for treatment of hepatic cancer under external magnet control.

Effect of porous titanium coated with IGF-1 and TGF-β_1 loaded gelatin microsphere on function of MG63 cells

Porous titanium with porosity of 60% was prepared by metal injection molding（MIM）,and coated with gelatin sustained-release microspheres which were made by improved emulsified cold condensation method.The effects of porous titanium coated with insulin-like growth factor-1（IGF-1） and transforming growth factor-β1（TGF-β1） gelatin microspheres on the function of MG63 cells were evaluated in vitro.The results show that porous titanium coated with gelatin sustained-release microspheres has no cytotoxicity.The IGF-1 and TGF-β1 loading concentrations are positively correlative with the proliferation and differentiation of MG63 after co-culturing with the concentrations of IGF-1 and TGF-β1 gelatin microspheres in the range of 0.1-10 ng/mg and 0.25-2.5 ng/mg,respectively.The MG63 cells exhibit the best proliferation and differentiation with the IGF-1 and TGF-β1 loading concentrations of 10 ng/mg and 2.5 ng/mg,respectively.The joint application of IGF-1 and TGF-β1 group,which promote adhesion,proliferation and differentiation of MG63 cells,is superior to a single application group.

光交联复合水凝胶支架中人牙髓干细胞的成骨/成牙分化能力

背景:甲基丙烯酸酐改性明胶(gelatin-methacryloyl,Gel-MA)与经处理牙本质基质(treated dentin matrix,TDM)在一定比例下经过紫外线交联后形成的复合水凝胶支架具有良好的孔隙率、机械性能、溶胀性能及生物降解率,这为临床上年轻恒牙的牙髓再生提供了新的思路和方法。目的:探究1∶2质量比Gel-MA/TDM复合光交联水凝胶支架对人牙髓干细胞增殖能力及成骨/成牙本质分化能力的影响。方法:将第3代牙髓干细胞接种至1∶2质量比Gel-MA/TDM复合水凝胶支架中,采用CCK-8实验检测人牙髓干细胞在复合水凝胶支架中的增殖能力。将第3代牙髓干细胞接种至1∶2质量比Gel-MA/TDM复合水凝胶支架中并进行成骨诱导,采用碱性磷酸酶染色及茜素红染色观察矿化结节的形成情况,采用RT-PCR检测成牙相关因子(牙本质基质蛋白1、牙本质涎磷蛋白)和成骨相关因子(骨钙素、Runt相关转录因子2)的基因表达。结果与结论:①CCK-8检测结果显示,前7 d的牙髓干细胞增殖能力明显升高,第10天时速度减缓;②碱性磷酸酶染色及茜素红染色结果显示,Gel-MA/TDM复合水凝胶组牙髓干细胞的碱性磷酸酶活性及矿化结节生成强于单纯Gel-MA水凝胶组(P<0.05);③RT-PCR结果显示,Gel-MA/TDM复合水凝胶组牙髓干细胞中牙本质基质蛋白1、牙本质涎磷蛋白、骨钙素、Runt相关转录因子2的基因表达量明显高于单纯Gel-MA水凝胶组(P<0.05),且14 d基因表达量明显高于7 d(P<0.05)。结果表明,培养在1∶2 Gel-MA/TDM复合水凝胶支架上的牙髓干细胞表现出较好的增殖能力,能够强化牙髓干细胞的成骨、成牙本质分化能力。

Gelatin／BaTiO3核壳复合粒子的制备及电场响应性能研究

以平均粒径为0．7～0．9μm的明胶（Gelatin）微球为基核，通过定向沉积自组装法成功制各了以Gelatin为核、BaTiO3为壳的Gelatin／BaTiO3核壳复合粒子。利用TEM、XRD、FT-IR、TG和光学接触角测量等技术对复合粒子的形貌、结构、组成及表面亲水性能进行了研究。结果表明，复合粒子为球形微粒，具有良好的表面亲水性和分散稳定性，BaTiO3壳层约占粒子总质量的18．8％，具有立方相晶相结构。将粒子分散到水凝胶弹性体中，测量在有／无电场作用下得到的弹性体的储能模量，借以考察复合粒子在弹性体中的电场响应性能，发现Gelatin／BaTiO3复合粒子的电场响应性能明显强于纯BaTiO3粒子。说明将BaTiO3包覆在聚合物上能显著提高BaTiO3粒子的电场响应性能。

生物3D打印仿生支架促进肩袖损伤后的愈合

背景:大多数肩袖损伤发生于冈上肌腱,由于肌腱组织缺少血管以及肩袖复杂的解剖结构,临床治疗效果非常有限。组织工程技术和干细胞生物学的快速发展为提高肌腱修复质量带来了新的希望。目的:通过生物3D打印技术制备人脐带间充质干细胞/甲基丙烯酸酐化明胶复合支架,观察该支架修复肩袖损伤的效果。方法:(1)体外细胞实验:制备明胶微载体,将人脐带间充质干细胞接种于明胶微载体表面构建组织工程化干细胞。制备甲基丙烯酸酐化明胶水凝胶打印墨水,使用甲基丙烯酸酐化明胶水凝胶打印墨水重悬组织工程化干细胞,放入3D打印机的生物墨水容器中进行打印,蓝光照射固化5 min后即得人脐带间充质干细胞/甲基丙烯酸酐化明胶复合支架。通过死活染色、CCK-8实验检测支架内人脐带间充质干细胞的活性。(2)动物体内实验:采用随机区组设计方法将24只SD大鼠随机4组,每组6只:正常组不进行任何处理,肩袖损伤组、单纯支架组、细胞支架组建立冈上肌腱撕裂的肩袖损伤模型,单纯支架组、细胞支架组造模后分别将甲基丙烯酸酐化明胶支架、人脐带间充质干细胞/甲基丙烯酸酐化明胶复合支架植入肌腱损伤处。术后4周,分别进行大鼠行为学测试及肩袖冈上肌腱组织学病理组织形态观察。结果与结论:(1)体外细胞实验:死活染色结果显示,明胶微载体可减轻3D打印过程对人脐带间充质干细胞造成的损伤,随着培养时间的延长,支架内的人脐带间充质干细胞存活率升高;CCK-8实验结果显示,随着培养时间的延长,支架内的人脐带间充质干细胞活性无明显变化。(2)动物体内实验:行为学测试结果显示,相较于肩袖损伤组、单纯支架组,细胞支架组大鼠四肢运动功能明显改善;肩袖冈上肌腱苏木精-伊红与Masson染色结果显示,相较于肩袖损伤组、单纯支架组,细胞支架组肌纤维排列较规律,无明显的炎性细胞浸润,胶原容积百分比降低;免疫荧光染色结果显示,相较于肩袖损伤组、单纯支架组,细胞支架组肩袖冈上肌腱内白细胞介素6、肿瘤坏死因子α蛋白表达明显降低。(3)结果表明,生物3D打印的人脐带间充质干细胞/甲基丙烯酸酐化明胶复合支架可促进肩袖损伤组织修复再生。

Decolorization of reactive dyes by laccase immobilized in alginate/gelatin blent with PEG

To achieve effective decolorization of reactive dyes,laccase immobilization was investigated.Laccase 0.2%(m/V)(Denilite IIS) was trapped in beads of alginate/gelatin blent with polyethylene glycol(PEG),and then the supporters were activated by cross-linking with glutaraldehyde.The results of repeated batch decolorization showed that gelatin and appropriate concentration of glutaraldehyde accelerated the decolorization of Reactive Red B-3BF(RRB);PEG had a positive effect on enzyme stability and led to an inc...