Estimation of cancer cell migration in biomimetic random/oriented collagen fiber microenvironments

Increasing data indicate that cancer cell migration is regulated by extracellular matrixes and their surrounding biochemical microenvironment,playing a crucial role in pathological processes such as tumor invasion and metastasis.However,conventional two-dimensional cell culture and animal models have limitations in studying the influence of tumor microenvironment on cancer cell migration.Fortunately,the further development of microfluidic technology has provided solutions for the study of such questions.We utilize microfluidic chip to build a random collagen fiber microenvironment(RFM)model and an oriented collagen fiber microenvironment(OFM)model that resemble early stage and late stage breast cancer microenvironments,respectively.By combining cell culture,biochemical concentration gradient construction,and microscopic imaging techniques,we investigate the impact of different collagen fiber biochemical microenvironments on the migration of breast cancer MDA-MB-231-RFP cells.The results show that MDA-MB-231-RFP cells migrate further in the OFM model compared to the RFM model,with significant differences observed.Furthermore,we establish concentration gradients of the anticancer drug paclitaxel in both the RFM and OFM models and find that paclitaxel significantly inhibits the migration of MDA-MB-231-RFP cells in the RFM model,with stronger inhibition on the high concentration side compared to the low concentration side.However,the inhibitory effect of paclitaxel on the migration of MDA-MB-231-RFP cells in the OFM model is weak.These findings suggest that the oriented collagen fiber microenvironment resembling the late-stage tumor microenvironment is more favorable for cancer cell migration and that the effectiveness of anticancer drugs is diminished.The RFM and OFM models constructed in this study not only provide a platform for studying the mechanism of cancer development,but also serve as a tool for the initial measurement of drug screening.

Anti-abrasion collagen fiber-based membrane functionalized by UiO-66-NH_(2)with ultra-high efficiency and stability for oil-in-water emulsions separation

Membrane separation strategies offer promising platform for the emulsion separation.However,the low mechanical strength of membrane separation layers and the trade-off between separation flux and efficiency present significant challenges.In this study,we report a CFM@UiO-66-NH_(2)membrane with high separation flux,efficiency and stability,through utilizing a robust anti-abrasion collagen fiber membrane(CFM)as the multifunctional support and UiO-66-NH_(2)by an in-situ growth as the separation layer.The high mechanical strength of the CFM compensated for the weakness of the separation layer,while the charge-breaking effect of UiO-66-NH_(2),along with the size sieving of its constituent separating layers and the capillary effect of the collagen fibers,contributed to the potential for efficient separation.Additionally,the CFM@UiO-66-NH_(2)membrane exhibited superhydrophilic properties,making it suitable for separating oil-in-water microemulsions and nanoemulsions stabilized by anionic surfactants.The membrane demonstrated remarkable separation efficiencies of up to 99.960%and a separation flux of370.05 L·m^(-2)·h^(-1).Moreover,it exhibits stability,durability,and abrasion resistance,maintaining excellent separation performance even when exposed to strong acids and alkalis without any damage to its structure and performance.After six cycles of reuse,it achieved a separation flux of 417.97 L·m^(-2)·h^(-1)and a separation efficiency of 99.747%.Furthermore,after undergoing 500 cycles of strong abrasion,the separation flux remained at 124.39 L·m^(-2)·h^(-1),with a separation efficiency of 99.992%.These properties make it suitable for the long-term use in harsh operating environments.We attribute these properties to the electrostatic effect resulting from the amino group on UiO-66-NH_(2)and its in-situ growth on the CFM,which forms a size-screening separation layer.Our work highlights the potential of the CFM@UiO-66-NH_(2)membrane as an environmentally friendly size-screening material for the efficient emulsion wastewater separation.

Three-dimensional remodeling of collagen fibers within cervical tissues in pregnancy

The cervix is a collagen-rich connective tissue that must remain closed during pregnancy while undergoing progressive remodeling in preparation for delivery,which begins before the onset of the preterm labor process.Therefore,it is important to resolve the changes of collagen flbers during cervical remodeling for the prevention of preterm labor.Herein,we assessed the spatial organization of collagen flbers in a three-dimensional(3D)context within cervical tissues of mice on day 3,9,12,15 and 18 of gestation.We found that the 3D directional variance,a novel metric of alignment,was higher on day 9 than that on day 3 and then gradually decreased from day 9 to day 18.Compared with two-dimensional(2D)approach,a higher sensitivity was achieved from 3D analysis,highlighting the importance of truly 3D quantification.Moreover,the depthdependent variation of 3D directional variance was investigated.By combining multiple 3D directional variance-derived metrics,a high level of classification accuracy was acquired in distinguishing different periods of pregnancy.These results demonstrate that 3D directional variance is sensitive to remodeling of collagen fibers within cervical tissues,shedding new light on highly-sensitive,early detection of preterm birth(PTB).

Adsorptive Recovery of Uranium from Nuclear Fuel Industrial Wastewater by Titanium Loaded Collagen Fiber

Effective recovery of UO2+2 from wastewater is essential for nuclear fuel industry and related industries.In this study,a novel adsorbent was prepared by loading titanium(Ti4+) onto collagen fiber(TICF),and its physical and chemical properties as well as adsorption to UO2+2 in nuclear fuel industrial wastewater were investigated.It is found that TICF can effectively recover UO2+2 from the wastewater with excellent adsorption capacity.The adsorption capacity is 0.62 mmol·g-1 at 303 K and pH 5.0 when the initial concentration of UO2+2 is 1.50 mmol·L-1.The adsorption isotherms can be described by the Langmuir equation and the adsorption capacity increases with temperature.The effect of co-existed F on the adsorption capacity for UO2+2 is significant,which can be eliminated by adding aluminum ions as complexing agent,while the other co-existed ions in the solutions,including HCO-3,Cl-,NO-3,Ca2+,Mg2+ and Cu2+,have little effect on the adsorption capacity for UO2+2.The saturated TICF after UO2+2 adsorption can be regenerated by using 0.2 mol·L-1 nitrate(HNO-3) as desorption agent,and the TICF can be reused at least three times.Thus the TICF is a new and effective adsorbent for the recovery of UO2+2 from the wastewater.

Characterization of Amino Terminated Hyperbranched Collagen Fiber and Adsorption Thermodynamics to Cr(Ⅵ)

In this study, a novel adsorption material amino terminated hyperbranched polyamide collagen fiber( CF-HBPN)was prepared by loading amino terminated hyperbranched polyamide( HBPN) which was synthesized by polycondensation of methacrylate and diethylenetriamine onto the surface of collagen fiber( CF) with glutaraldehyde as the cross-linking agent. X-ray photoelectron spectroscopy( XPS) and thermogravimetric analysis( TGA) were employed to characterize the structures of CF and CFHBPN. In addition,the adsorption property of CF-HBPN toward Cr( Ⅵ) and adsorption thermodynamic were studied as well. The experimental results indicated that the Cr( Ⅵ) 's removal rate by CF-HBPN was 3. 09 higher than that of CF under the same conditions. Langmuir single layer adsorption model was found more suitable to describe the adsorption process than Freundlich adsorption model. The adsorption process was an endothermic reaction. The adsorption efficiency was enhanced with the increase of temperature. X-ray diffraction( XRD) was employed to elucidate the difference between CF-HBPN and Cr( Ⅵ) loaded CF-HBPN[CF-HBPN-Cr( Ⅵ) ].

The improvement of dispersity,thermal stability and mechanical properties of collagen fibers by silane modification:an exploration for developing new leather making technology

The effect of hydrophobic modification on the performances of collagen fibers(CFs)was investigated by using silane coupling agents with different alkyl chains as hydrophobic modifiers.It was found silane could be easily grafted onto CF surface through covalent bonds under 5%water content.This modification led to the transformation of surface wettability of CF from hydrophilic to hydrophobic.Interestingly,the change of surface wettability resulted in substantial improvement of the modified CF properties,presenting well dispersity of collagen fibers,higher thermal stability and enhanced mechanical properties in comparison with natural CF.The degree of improvement mainly depended on the length of alkyl chain in silane.Longer alkyl chain produced strong hydrophobicity and subsequently more superior performances of the modified CF.When the length of alkyl chain increased to 18 carbon atoms,the modified CF possessed durable superhydrophobicity even exposed to aqueous solutions of different pH,UV,and organic solvents,and had excellent thermal and mechanical properties like leather fibers.In general,this work clearly revealed that the properties of CF are closely and positively related to the hydrophobicity,which is suggestive in developing new leather making technology.

Composite nanofiltration membrane with tannic acid coordinated collagen fibers for enhanced molecule separation

Biomass-based membranes have attracted increasing attentions due to their cheap and sustainable advantages.In this work,a novel thin-fiilm composite(TFC)nanofiltration(NF)membrane was fabricated through a facial interfacial polymerization(IP)process by initiate the crosslinking reaction between collagen fibers(CFs)and tannic acid(TA).The increased TA concentrations endowed the TFC membrane with a higher crosslinking degree,a thicker active layer and a rougher top surface.At optimized condition with 0.60 mg TA decoration,the TFC-3 membrane exhibited a high water permeability of 23.49 L m^(-2)h^(-1)bar^(-1)with high rejections above 98.0%for congo red,reactive blue 19,coomassie blue G-250,and methyl blue.Furthermore,the membrane preserved remarkable salt retentions(93.3%for Na_(2)SO_(4),83.4%for MgSO_(4),36.2%for MgCl_(2),and 26.4%for NaCl)and satisfying operation stability.This facial fabrication method offered a new insight to employ biomass for molecular precise separation.

Collagen fiber membrane-derived chemically and mechanically durable superhydrophobic membrane for high- performance emulsion separation

Developing high-performance separation membrane with good durability is a highly desired while challenging issue.Herein,we reported the successful fabrication of chemically and mechanically durable superhydrophobic membrane that was prepared by embedding UiO-66 as size-sieving sites within the supramolecular fiber structure of collagen fiber membrane(CFM),followed by the polydimethylsiloxane(PDMS)coating.The as-prepared CFM/UiO-66(12)/PDMS membrane featured capillary effect-enhanced separation flux and homogeneous porous channels guaranteed high separation efficiency.When utilized as double-layer separation membranes,this new type of composite membranes separated various surfactant stabilized water-in-oil microemulsions and nanoemulsions,with the separation efficiency high up to 99.993%and the flux as high as 973.3 L m−2 h−1.Compared with commercial polytetrafluoro ethylene(PTFE)membrane,the advantage of the double-layer CFM/UiO-66(12)/PDMS membranes in separation flux was evident,which exhibited one order of magnitude higher than that of commercial PTFE membrane.The CFM/UiO-66(12)/PDMS membrane was acid-alkali tolerant,UV-aging resistant and reusable for emulsion separation.Notably,the CFM/UiO-66(12)/PDMS membrane was mechanically durable against strong mechanical abrasion,which was still capable of separating diverse water-in-oil emulsions after the abrasion with sandpaper and assembled as double-layer separation membranes.We anticipate that the combination of CFM and metal organic frameworks(MOFs)is an effective strategy for fabricating high-performance separation membrane with high mechanical and chemical durability.

The improvement of dispersity, thermal stability and mechanical properties of collagen fibers by silane modification: an exploration for developing new leather making technology

The effect of hydrophobic modification on the performances of collagen fibers(CFs)was investigated by using silane coupling agents with different alkyl chains as hydrophobic modifiers.It was found silane could be easily grafted onto CF surface through covalent bonds under 5%water content.This modification led to the transformation of surface wettability of CF from hydrophilic to hydrophobic.Interestingly,the change of surface wettability resulted in substantial improvement of the modified CF properties,presenting well dispersity of collagen fibers,higher thermal stability and enhanced mechanical properties in comparison with natural CF.The degree of improvement mainly depended on the length of alkyl chain in silane.Longer alkyl chain produced strong hydrophobicity and subsequently more superior performances of the modified CF.When the length of alkyl chain increased to 18 carbon atoms,the modified CF possessed durable superhydrophobicity even exposed to aqueous solutions of different pH,UV,and organic solvents,and had excellent thermal and mechanical properties like leather fibers.In general,this work clearly revealed that the properties of CF are closely and positively related to the hydrophobicity,which is suggestive in developing new leather making technology.

In situ Growing PtCo Bimetallic Catalyst on Plant Tannin-grafted Collagen Fiber for Catalytic Hydrogenation of Cinnamaldehyde with Desirable Performance

PtCox bimetallic nanoparticles（NPs） supported on tannin-grafted collagen fiber（CF-BT） have been pre- pared via a novel synthetic strategy, and applied for catalytic hydrogenation of cinnamaldehyde（CAL）, a typic unsa- turated aldehyde. The catalysts were systematically artd specifically characterized by means of XRD, XPS, TEM-EDX and SEM to clarify the structure-property correlation. It was found that the PtCox/CF-BT catalysts exhi- bited significantly enhanced catalytic activity and desirable stability in catalytic hydrogenation of CAL, which is ascribed to the synergistic interaction between bimetallic components, the effective dispersion, the anchoring role of CF-BT matrix on bimetallic NPs, as well as the lower mass transfer resistance of the matrix.

Bletilla striata polysaccharide modified collagen fiber composite sponge with rapid hemostasis function

Emergencies often result in uncontrollable bleeding, which is thought to be the leading cause of death at the scene of the injured. Among various hemostasis scenarios, collagen fiber (CF) is gradually replacing traditional hemostatic materials due to its superior properties and ease of sourcing from animals. Herein, we use CF and the natural herba-ceous Bletilla striata as raw materials to prepare a collagen fiber-oxidized Bletilla striata composite hemostatic sponge (CFOB). During the cross-linking process, the triple helix structure of collagen stays intact, and its porous three- dimensional network structure brings excellent bulkiness and water absorption properties. Experiments show that the optimal amount of sponge CFOB-10, namely oxidized Bletilla striata polysaccharide 0.5 mg/mL and CF 5 mg/mL, only needed 25 ± 4.06 s for hemostasis time in the rat liver hemorrhage model. In addition, CFOB meets the safety performance requirements of cytotoxicity classification standard 0. Therefore, the optimal amount of CFOB is an excel-lent new hemostatic material with application potential.

A 3D biophysical model for cancer spheroid cell-enhanced invasion in collagen-oriented fiber microenvironment

The process of in situ tumors developing into malignant tumors and exhibiting invasive behavior is extremely complicated.From a biophysical point of view,it is a phase change process affected by many factors,including cell-to-cell,cell-to-chemical material,cell-to-environment interaction,etc.In this study,we constructed spheroids based on green fluorescence metastatic breast cancer cells MDA-MB-231 to simulate malignant tumors in vitro,while constructed a three-dimensional(3D)biochip to simulate a micro-environment for the growth and invasion of spheroids.In the experiment,the 3D spheroid was implanted into the chip,and the oriented collagen fibers controlled by collagen concentration and injection rate could guide the MDA-MB-231 cells in the spheroid to undergo directional invasion.The experiment showed that the oriented fibers greatly accelerated the invasion speed of MDA-MB-231 cells compared with the traditional uniform tumor micro-environment,namely obvious invasive branches appeared on the spheroids within 24 hours.In order to analyze this interesting phenomenon,we have developed a quantitative analyzing approach to explore strong angle correlation between the orientation of collagen fibers and invasive direction of cancer cell.The results showed that the oriented collagen fibers produced by the chip can greatly stimulate the invasion potential of cancer cells.This biochip is not only conducive to modeling cancer cell metastasis and studying cell invasion mechanisms,but also has the potential to build a quantitative evaluation platform that can be used in future chemical drug treatments.

A theoretical analysis on second harmonic generation for transverse and longitudinal slice collagen fiber

Microscopic imaging based on second-harmonic generation has been proving to be a powerful tool for biomedical studies, especially in that tissues with

Rapid and efficient characterization of cervical collagen orientation using linearly polarized colposcopic images

Collagen provides tissue strength and structural integrity.Quanti fication of the orientated dispersion of collagen fibers is an important factor when studying the mechanical properties of the cervix.In this study,for the first time,a new method for rapid characterization of the collagen fiber orientations of the cervix using linearly polarized light colposcopy is presented.A total of 24 colposcopic images were captured using a cross-polarized imaging system with white LED light sources.In the preprocessing stage,the Red channel of the RGB image was chosen,which contains no information of the blood vessels because of the low-absorption of blood cells in the red region.OrientationJ,which is an ImageJ plug-in,was used to estimate the local orientation of the collagen fibers.The result shows that in the nonpregnant cervix,the middle zone(Zone 2)has circumferentially aligned collagen fibers while the inner zone(Zone 1)has randomly arranged.The collagen fiber dispersion in Zone 2 is much smaller than that in Zone 1 at all four quadrants region(anterior,posterior,left,and right quadrant).This new analysis technique could potentially combine with diagnostic tools to provide a quantitative platform of collagen fibers in the clinic.

Skin collagen fiber-based radar absorbing materials

By using skin collagen fiber (CF) as raw material,Schiff base structure containing CF (Sa-CF) was synthesized through CF-salicylaldehyde reaction.Then a novel radar absorbing material (Fe-Sa-CF) was prepared by chelating reaction between Sa-CF and Fe 3+.The coaxial transmission and reflection method was used to analyze the complex permittivity and complex magnetic permeability of these CF-based materials,and the radar cross section (RCS) method was used to investigate their radar absorbing properties in the frequency range of 1.0-18.0 GHz.Experimental results indicated that the conductivity of CF increased from initial 1.08×10-11 to 2.86×10-6 S/cm after being transferred into Fe-Sa-CF,and its dielectric loss tangent (tanδ) in the frequency range of 1.0-17.0 GHz also increased.These facts suggest that the Fe-Sa-CF is electric-loss type radar absorbing material.In the frequency range of 3.0-18.0 GHz,Sa-CF (1.0 mm in thickness) exhibited somewhat radar absorbing property with maximum radar reflection loss (RL) of-4.73 dB.As for Fe-Sa-CF,the absorbing bandwidth was broadened,and the absorbing intensity significantly increased in the frequency range of 1.0-18.0 GHz where a maximum radar RL of-9.23 dB was observed.In addition,the radar absorbing intensity of Fe-Sa-CF can be further improved by increasing membrane thickness.When the thickness reached to 2.0 mm,the RL values of Fe-Sa-CF were-15.0-18.0 dB in the frequency range of 7.0-18.0 GHz.Consequently,a kind of novel radar absorbing material can be prepared by chemical modification of collagen fiber,which is characterized by thin thickness,low density,broad absorption bandwidth and high absorption intensity.

A method of removing retardance induced by scattering of collagenous fiber bundles

In this work,we report a method of removing scattering induced retardance in polarization sensitive fnll field optical coherence tomography(PS-FFOCT).First,the Mueller matrix that describes its operation is derived.The thickness invariant retardance induced by the scattering of collagenous fiber bundles is then used to find the accurate values of the birefringence of the layers that consist collagenous fibers.Finally,the initial en face birefringent images of in vitro beef tendon samples are presented to demonstrate the capability of our method.

APPLICATION OF THE COLLAGENOUS FIBER FROM THE SOLID WASTES OF LEATHER FOR PAPERMAKING

The capability of pulping for the solid waste of leather was investigated. The properties of paper that made up of collagenous fiber and plant fiber were also analyzed. The result showed that by proper treatment, solid waste of leather could be made into collagen fiber for papermaking. The physical strength of paper can be enhanced by appending collagenous fiber in a proper propriety.

胶原纤维基吸附材料的研究进展

吸附在化学化工等领域有着至关重要的作用,开发绿色、低成本的高效吸附材料是未来吸附分离的重要发展方向。胶原纤维(CFs)是一种来源于动物皮的天然生物质资源,其具有独特的三维多层级结构,同时含有丰富的活性官能团。因此,利用CFs制备高性能吸附材料具有较高的研究价值和应用潜力。论文主要介绍了近年来CFs固化单宁、负载金属离子和接枝功能基团等CFs基吸附材料的制备方法,讨论了吸附材料在放射性核素离子、有毒重金属离子、无机阴离子、有机污染物的去除,以及天然产物的吸附分离和细胞固定等方面的应用,并对CFs基吸附材料未来的发展方向进行了展望。

牦牛肺脏内纤维和纤维蛋白分布与表达的增龄性变化研究

为探究牦牛肺内纤维结构及其组成蛋白的增龄性变化,本研究采用Verhoeff’s Van Gieson(EVG)染色和网状纤维染色观察胶原纤维、弹性纤维及网状纤维在初生、幼年和成年牦牛肺组织中的分布情况;利用免疫组化、免疫荧光和蛋白免疫印迹对不同年龄组牦牛肺组织中Ⅰ、Ⅲ、Ⅳ型胶原蛋白和弹性蛋白的分布特征及蛋白表达水平进行研究。结果显示,胶原纤维、网状纤维及三种胶原蛋白的分布位置基本一致,主要分布于牦牛肺脏支气管及血管外膜、软骨片、气管腺,支气管上皮细胞基膜、平滑肌层及肺泡隔也有较少量分布;而弹性蛋白及弹性纤维大量分布于支气管上皮细胞基膜、肺血管及肺泡隔中。四种蛋白的表达趋势基本一致,均在幼年组表达最高,初生组表达最低,且各年龄组间均差异显著(P<0.05)。结果表明,牦牛肺内弹性纤维、胶原纤维、网状纤维分布丰富,可使牦牛肺具有更好的收缩和舒张能力,有利于其对高寒缺氧环境的适应;Ⅰ、Ⅲ、Ⅳ型胶原蛋白和弹性蛋白表达量与年龄呈相关性,在幼年段表达最高,说明牦牛肺脏低氧适应性结构的形成在幼年段最为显著。本研究为进一步探究牦牛肺脏低氧适应结构提供了基础资料。

废弃胶原纤维固化单宁吸附材料原位Fe_(2)O_(3)微波催化裂解减容研究

胶原纤维基吸附材料在核素吸附中表现出优异的性能,但同时产生放射性固废的处置问题。针对这一问题,利用原位Fe_(2)O_(3)对胶原纤维固化单宁(CFT)材料进行催化裂解,以实现废弃CFT的有效减容。通过热重分析技术对其热解过程进行研究,结果表明通过将Fe^(3+)负载至CFT(Fe-CFT)再进行裂解,能够使裂解温度降至约450℃,比CFT直接裂解温度降低了约150℃,残渣率降至9.5%。进一步以纳米Fe_(2)O_(3)为传热介质,在微波条件下对Fe-CFT进行裂解,Fe-CFT残渣率降至2.1%。利用傅里叶变换红外光谱仪、X射线衍射仪和元素分析仪对残渣进行表征,结果表明反应过程中Fe^(3+)原位生成的Fe_(2)O_(3)有效促进CFT的氧化裂解。综上,通过原位Fe_(2)O_(3)有效降低CFT的裂解温度,裂解后残渣率低,实现了废弃CFT的安全高效减容。