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.

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.

Dietary protein levels changed the hardness of muscle by acting on muscle fiber growth and the metabolism of collagen in sub-adult grass carp(Ctenopharyngodon idella)

Background:Nutrient regulation has been proven to be an effective way to improve the flesh quality in fish.As a necessary nutrient for fish growth,protein accounts for the highest proportion in the fish diet and is expensive.Although our team found that the effect of protein on the muscle hardness of grass carp was probably related to an increased collagen content,the mechanism for this effect has not been deeply explored.Moreover,few studies have explored the protein requirements of sub-adult grass crap(Ctenopharyngodon idella).Therefore,the effects of different dietary protein levels on the growth performance,nutritional value,muscle hardness,muscle fiber growth,collagen metabolism and related molecule expression in grass carp were investigated.Methods:A total of 450 healthy grass carp(721.16±1.98 g)were selected and assigned randomly to six experimen-tal groups with three replicates each(n=25/replicate),and were fed six diets with 15.91%,19.39%,22.10%,25.59%,28.53%and 31.42%protein for 60 d.Results:Appropriate levels of dietary protein increased the feed intake,percentage weight gain,specific growth rate,body composition,unsaturated fatty acid content in muscle,partial free amino acid content in muscle,and muscle hardness of grass carp.These protein levels also increased the muscle fiber density,the frequency of new muscle fibers,the contents of collagen and IGF-1,and the enzyme activities of prolyl 4-hydroxylases and lysyloxidase,and decreased the activity of matrix metalloproteinase-2.At the molecular level,the optimal dietary protein increased col-lagen type Iα1(Colα1),Colα2,PI3K,Akt,S6K1,La ribonucleoprotein domain family member 6a(LARP6a),TGF-β1,Smad2,Smad4,Smad3,tissue inhibitor of metalloproteinase-2,MyoD,Myf5,MyoG and MyHC relative mRNA levels.The levels of the myostatin-1 and myostatin-2 genes were downregulated,and the protein expression levels of p-Smad2,Smad2,Smad4,p-Akt,Akt,LARP6 and Smad3 were increased.Conclusions:The appropriate levels of dietary protein promoted the growth of sub-adult grass carp and improved muscle hardness by promoting the growth of muscle fibers,improving collagen synthesis and depressing collagen degradation.In addition,the dietary protein requirements of sub-adult grass carp were 26.21%and 24.85%according to the quadratic regression analysis of growth performance(SGR)and the muscle hardness(collagen content),respectively.

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.

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) ].

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).

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.

胶原生物炭/g-C_(3)N_(4)/WO_(3)复合材料光催化去除水体中Cr(Ⅵ)

以制革领域中废弃的皮胶原纤维为原料,基于鞣制化学中的矿物鞣制原理,将钨离子负载在皮胶原纤维上,并经过高温热解得到负载氧化钨的生物炭材料(C/WO_(3)),最后采用机械混合法将石墨相氮化碳(g-C_(3)N_(4))与C/WO_(3)进行复合,制备得到g-C_(3)N_(4)/C/WO_(3)光催化剂。采用扫描电子显微镜、X射线衍射和荧光光谱等进行形貌结构和性能的表征,并且以Cr(Ⅵ)作为目标污染物,研究了g-C_(3)N_(4)/C/WO_(3)对Cr(Ⅵ)的去除效果。结果表明,g-C_(3)N_(4)/C/WO_(3)比表面积达到244.62 m2/g,远高于单独的g-C_(3)N_(4)(9.95 m2/g),同时g-C_(3)N_(4)/C/WO_(3)的光催化性能明显提升。Cr(Ⅵ)的去除实验表明,当催化剂用量为0.1 g,Cr(Ⅵ)初始质量浓度为50 mg/L,溶液pH为2时,g-C_(3)N_(4)/C/WO_(3)对Cr(Ⅵ)的去除率高达99.99%,并且几乎不受水中共存物质的影响,循环性能比较稳定。

低温长时间热处理过程中氧化和加热对海参体壁胶原纤维结构的影响

以新鲜海参为研究对象,考查低温(60℃)长时间热处理过程中氧化和加热对其质构特性的影响,并进一步从新鲜海参体壁中提取完整的胶原纤维,分别进行氧化处理、热处理及氧化协同热处理后,采用差示扫描量热(DSC)仪、冷冻扫描电子显微镜(cryo-SEM)、傅里叶变换红外光谱(FTIR)仪、电子自旋共振波谱(ESR)仪等对其热稳定性、微观结构、蛋白质二级结构、氧化程度等变化情况进行研究。结果表明:单一氧化处理对胶原纤维仅有氧化降解作用。单一热处理会使胶原纤维发生氧化、变性、降解等变化。相较于两种单一处理方式,经氧化协同热处理后,胶原纤维结构被破坏得更加明显,处理1 h后,胶原纤维内的蛋白聚糖桥连结构发生明显断裂,处理24 h后,在15~24℃附近出现新的吸热峰,胶原纤维发生明胶化;随着处理时间的延长,胶原纤维结构的孔径进一步收缩,且发生破损;氧化协同热处理能促进热处理对胶原纤维的氧化程度,并使大分子蛋白质发生降解,增加羟脯氨酸、糖胺聚糖(GAG)等可溶性小分子物质溶出。因此,氧化协同热处理能使胶原纤维发生氧化、变性、聚集、降解等变化,进而影响海参体壁的质构特性。

脂肪干细胞复合透明质酸支架对糖尿病小鼠皮肤创面愈合的影响实验研究

目的:探讨脂肪干细胞(ADSCs)复合透明质酸(HA)支架对糖尿病小鼠皮肤创面愈合的影响。方法:使用高蔗糖和高脂肪食物饲养30只小鼠10周,第11周于腹膜腔内注射50 mg/kg链脲佐菌素建立糖尿病小鼠模型。切取10只健康小鼠双侧腹股沟区域的脂肪组织,分离培养ADSCs,制备ADSCs-HA复合物。将30只糖尿病小鼠随机分为ADSCs-HA组、HA组和对照组,每组10只,每只小鼠背部制备2个创面模型。其中,ADSCs-HA组小鼠创面基底下及创周皮下注射0.3 ml ADSCs-HA复合物(ADSCs密度6×10^(7)个/ml,HA浓度10 mg/ml),HA组和对照组小鼠同部位分别注射0.3 ml同等浓度HA、0.3 ml 0.9%氯化钠溶液。于术后3、7、10、14 d,观察各组创面愈合情况,并计算创面愈合率。记录各组创面愈合时间。术后14 d,采用免疫组织化学染色法观察创面组织微血管数量,行Masson染色观察创面组织胶原纤维沉积情况,采用RT-qPCR法检测创面组织生长因子及胶原蛋白mRNA表达水平。结果:术后7、10、14 d,ADSCs-HA组小鼠创面较对照组、HA组明显缩小,且ADSCs-HA组创面愈合率高于HA组和对照组(均P<0.05)。ADSCs-HA组创面愈合时间较HA组和对照组缩短(均P<0.05)。免疫组织化学染色结果显示,ADSCs-HA组术后14 d创面组织可见许多圆形或椭圆形微血管,数量多于HA组和对照组。Masson染色结果显示,与HA组和对照组比较,ADSCs-HA组术后14 d创面组织中的胶原纤维排列更整齐,胶原沉积以及胶原纤维更多。ADSCs-HA组术后14 d创面组织微血管数量、胶原纤维沉积百分比及血管内皮生长因子(VEGF)、成纤维细胞生长因子(FGF)、Ⅰ型胶原蛋白(COLⅠ)、COLⅢmRNA表达水平高于HA组和对照组(均P<0.05)。而HA组与对照组上述指标比较差异无统计学意义(均P>0.05)。结论:ADSCs复合HA支架能够促进糖尿病小鼠皮肤创面愈合。

Remodeling of skin nerve fibers during burn wound healing

Burn wound healing involves a complex sequence of processes. Recent studies have revealed that skin reinnervation may have an impact on physiological wound repair. Few studies have addressed the process of reinnervation and morphological changes in regenerated nerve fibers. The regeneration of neurites during full-thickness burn wound healing was determined by immunofluorescent staining using an anti-neurofilament protein monoclonal antibody, and three-dimensional morphology was observed under a laser scanning confocal microscope. Morphology and the volume fraction of collagen and nerve fibers were measured. Skin reinnervation increased during wound healing, peaked during the proliferative scar stage, and then decreased to lower levels during the maturation period. The results from the skin nerve fibers correlated with those from collagen using semi-quantitative analysis. Disintegration and fragmentation were observed frequently in samples from the proliferative stage, and seldom occurred during the maturation stage. There was a remodeling process of regenerated nerve fibers during wound healing, which comprised changed innervation density and topical morphology. The mechanism of remodeling for nerve fibers requires further investigation.

Evaluation of diffusion in gel entrapment cell culture within hollow fibers

AIM: To investigate diffusion in mammalian cell culture by gel entrapment within hollow fibers. METHODS: Freshly isolated rat hepatocytes or human oral epidermoid carcinoma (KB) cells were entrapped in type I collagen solutions and statically cultured inside microporous and ultrafiltration hollow fibers. During the culture time collagen gel contraction, cell viability and specific function were assessed. Effective diffusion coefficients of glucose in cell-matrix gels were determined by lag time analysis in a diffusion cell. RESULTS: Significant gel contractions occurred in the collagen gels by entrapment of either viable hepatocytes or KB cells. And the gel contraction caused a significant reduction on effective diffusion coefficient of glucose. The cell viability assay of both hepatocytes and KB cells statically cultured in hollow fibers by collagen entrapment further confirmed the existence of the inhibited mass transfer by diffusion. Urea was secreted about 50% more by hepatocytes entrapped in hollow fibers with pore size of 0.1 μm than that in hollow fibers with MWCO of 100 ku. CONCLUSION: Cell-matrix gel and membrane pore size are the two factors relevant to the limited mass transfer by diffusion in such gel entrapment of mammalian cell culture.

A collagen-based electrolyte-locked separator enables capacitor to have high safety and ionic conductivity

The conventional liquid electrolytes(LEs) have a high level of ionic conductivity;however, they often suffer from the poor processability and safety risks of potential leakage. Although solid-state electrolytes(SSEs) can solve these inherent problems of LEs, the ionic conductivity of most SSEs is several magnitudes lower than these of LEs. Herein, we report a novel strategy by building liquid ion-transport channels in a solid framework and prepared an electrolyte-locked separator(ELS) using a collagen fiber membrane(CFm). The liquid electrolyte was primarily infiltrated in the smaller voids of CFm, and its ionic conductivity could attain to 9.0×10-3 S cm-1 when the electrolyte absorption(EA) reached up to 112.0%. After centrifuging treatment, the electrolyte retentions(ER) and ionic conductivities of ELS were 108.93% and 8.37×10-3 S cm-1, respectively, which were much higher than those of commercial cellulose separator(CS), exerting excellent liquid-locking performances. In particular, the electrical double-layer capacitors(EDLC) assembled by ELS or CS were characterized and exhibited similar electrochemical performance,demonstrating the satisfactory ability and applicability of ELS for commercial use. In addition, the ELSbased EDLC exhibited favorable flexibility with relative lower loss of capacitance under different angles of bending.

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.

Macromolecule’s Orientation in a Nanofiber by Bubble Electrospinning

In the search for sustainable alternatives to harmful synthetic fibers,an increasing amount of research focuses on biomimicry and natural fibers.Sea silk is an exceptional textile material.It is a kind of natural silk produced using the long silky filaments secreted by a specific bivalve mollusk(Pinna nobilis);now at edge of extinction.This paper suggests a simple but effective way to prepare artificial sea silk from Mytilus edulis.A sea silk solution is prepared using a Mytilus edulis protein,and a polyvinyl alcohol(PVA)solution is mixed with the sea silk solution in order to produce artificial sea silk through a bubble electrospinning technique.The effects of the sea silk concentration on the nanofiber’s morphology and mechanical properties are studied experimentally.

Electrospinning and Electrospun Nanofibers

Electro-spinning is a very modern process which can be used in various purposes. We did this experimental work at Swerea IVF in Sweden during M. Sc in Textile Technology programme at University of Bor?s. We should especially thank our supervisor—Anna Thorvaldsson and course teacher—Ioannis S. Chronakis. In this report, we have tried to explain the basic manufacturing techniques of the electrospun nanofiber by the electro-spinning, how one can characterize it by SEM (Scanning Electron Microscopy) and its various applications in the practical field, e.g wound healing, Tissue Engineering Scaffold. The experimental work helped us a lot to gather sufficient knowledge about the electro-spinning process which we wanted to share with all.

Effects of AT1 Antagonist on MMP2, MMP9 Expression and Collagen Remodeling in Left Ventricle of Rabbit Undergoing Chronic Pressure Overload

Objectives To study the effects of AT1 antagonist on MMP2, MMP9 expression and collagen remodeling in left ventricle of rabbit undergoing chronic pressure overload. Methods 30 rabbits were randomly divided into 3 groups ( n = 10, each group), including sham operation group, abdominal aorta banded group (banded group), abdominal aorta banded +valsartan group (valsartan group). Twelve weeks after operation, hemodynamic parameters were acquired, then collagen volume fraction (CVF) and MMP2, MMP9 expression of left ventricle were measured by using VG and immunohistochemical stain. Results Compared with sham operation group, both MMP2 and MMP9 expression were enhanced in banded group; meanwhile, LVW/BW, LVEDP and CVF increased significantly. Compared with banded group, both MMP2 and MMP9 expression were weakened in valarstan group; simultaneously, LVW/BW, LVEDP and CVF decreased significantly. Conclusions Expression of MMP2 and MMP9 was enhanced in left ventricle of rabbit undergoing chronic pressure overload, which may be associated with collagen proliferation, ventricule remodeling and impaired heart function; Valsartan could inhibit collagen proliferation, prevent ventricule remodeling and preserve heart function by inhibiting abnormal expression of MMP2 and MMP9.

脆肉鲩器官组织胶原纤维染色观察

为研究饲喂蚕豆的脆肉鲩(Ctenopharyngodon idella)与普通草鱼不同器官组织中胶原纤维分布的特征,本试验对体质量7.0 kg的脆肉鲩和体质量4.5 kg的普通草鱼背部肌肉、腹部肌肉、心脏、肝胰脏、脾脏、前肠、中肠及后肠组织制作Masson染色切片,分析胶原纤维数量及分布。结果显示:器官组织中胶原纤维被染成蓝色,肌纤维被染成红色。脆肉鲩背肌、腹肌的胶原纤维染色更深、分布面积更大;背肌横切面、腹肌横切面的胶原纤维容积分数分别是普通草鱼的1.27倍和2.09倍,显示出脆肉鲩肌肉组织中胶原纤维含量更丰富;脆肉鲩肝胰脏、脾脏和心脏组织中,胶原纤维主要分布在肝胰脏门管区中的动脉、静脉管壁间隙、脾脏脾索内及心脏结缔组织中。对比发现,普通草鱼和脆肉鲩肠道组织平滑肌的大量胶原纤维分布在平滑肌细胞间,且脆肉鲩前、中、后肠的胶原纤维容积分数分别是普通草鱼的2.16倍、1.68倍和2.66倍。与肌肉、肝胰脏、脾脏和心脏相比,肠道的胶原纤维含量显著增多。器官组织的纵切和横切片显示,肌肉(骨骼肌细胞)、肠道(平滑肌细胞)和心脏(心肌细胞)的肌细胞类型并未发生改变,改变还是胶原纤维数量与分布、结缔组织的结构等。