In this study, yak bone collagen hydrolysate(YBCH)was produced by mixed proteases and provided to standard-diet mice at a different dose(low dose(LD), medium dose(MD), and high dose(HD))to investigate its effects on t...In this study, yak bone collagen hydrolysate(YBCH)was produced by mixed proteases and provided to standard-diet mice at a different dose(low dose(LD), medium dose(MD), and high dose(HD))to investigate its effects on the composition of gut microbiota and short-chain fatty acids(SCFA)production. It was found that YBCH was mainly composed of small molecular peptides whose molecular weight below 2 000 Da. Notably, supplementation with different doses of YBCH could significantly downregulate the ratio of Firmicutes to Bacteroidetes in the fecal microbiota. At the family level, the Lachnospiraceae abundance was significantly reduced in the YBCH gavage groups(mean reduction ratio 41.7 %, 35.2%, and 36.4% for LD, MD, and HD group, respectively). The predicted functions of gut microbes in the MD group were significantly increased at “lipid metabolism” and “glycan biosynthesis and metabolism”. Moreover, the SCFA production in the YBCH groups was elevated. Especially, the concentration of acetic acid, propionic acid, and butyric acid in the MD group was separately increased 79.7%, 89.2%, and 78.8% than that in the NC group. These results indicated that YBCH might be applied in the development of functional food for intestinal microecological regulation.展开更多
Bone collagen hydrolysates(peptides)derived from byproduct of animal product processing have been used to produce commercially valuable products due to their potential antioxidant activity.Maillard glycosylated reacti...Bone collagen hydrolysates(peptides)derived from byproduct of animal product processing have been used to produce commercially valuable products due to their potential antioxidant activity.Maillard glycosylated reaction is considered as a promising method to enhance the antioxidant activity of peptides.Hence,this research aims at investigating the Maillard glycosylation activity and antioxidant activity of bone collagen hydrolysates from different sources.In this study,3 glycosylated bone collagen hydrolysates were prepared and characterized,and cytotoxicity and antioxidant activity were analyzed and evaluated.The free amino groups loss,browning intensity,and fluorescence intensity of G-Cbcp(glycosylated chicken bone collagen hydrolysates(peptides))were the heaviest,followed by G-Pbcp(glycosylated porcine bone collagen hydrolysates(peptides))and G-Bbcp(glycosylated bovine bone collagen hydrolysates(peptides)).The results of amino acid analysis showed that amino acid composition of different bone collagen hydrolysates was significantly different and the amino acid decreased to different degrees after Maillard glycosylated reaction,which may lead to differences in Maillard glycosylated reaction activity.Furthermore,the 3 glycosylated hydrolysates showed no significant cytotoxicity.The results showed that glycosylation process significantly increased the antioxidant activity of bone collagen hydrolysates,and G-Cbcp showed the strongest antioxidant activity,followed by G-Pbcp and G-Bbcp.Therefore,compared with the bone collagen hydrolysates,3 glycosylated hydrolysates showed significant characteristic and structural changes,and higher antioxidant activity.展开更多
Ovine bones are the major by-products after slaughtered. The present study was conducted to extract and characterize acid soluble collagens(ASC) and pepsin soluble collagens(PSC) from ovine bones(Ujumuqin sheep). Ovin...Ovine bones are the major by-products after slaughtered. The present study was conducted to extract and characterize acid soluble collagens(ASC) and pepsin soluble collagens(PSC) from ovine bones(Ujumuqin sheep). Ovine bones collagen were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) and liquid chromatography-tandem mass spectrometry(LC-MS/MS) as type I collagen. The results of Fourier transform infrared(FTIR) spectra analysis testified the existence of triple superhelical structure in both ASC and PSC, showing pepsin did not disrupt the triple helical structure of ovine bones collagen. Glycine, accounting for one-third of total amino acids, was the major amino acid for ovine bones collagen. Higher imino acid content was responsible for higher thermal denaturation temperature of ovine bones collagen compared to fish collagens. The isoelectric point of ASC was lower than PSC due to the higher content of acidic amino acids. Therefore, this study provides the potential reference for collagen extraction and application of ovine bones by-procduct.展开更多
The aim of the present real time in vivo micro-computed tomography(m CT)and histologic experiment was to assess the efficacy of guided bone regeneration(GBR)around standardized calvarial critical size defects(CSD)usin...The aim of the present real time in vivo micro-computed tomography(m CT)and histologic experiment was to assess the efficacy of guided bone regeneration(GBR)around standardized calvarial critical size defects(CSD)using bone marrow-derived mesenchymal stem cells(BMSCs),and collagen membrane(CM)with and without tricalcium phosphate(TCP)graft material.In the calvaria of nine female Sprague-Dawley rats,full-thickness CSD(diameter 4.6 mm)were created under general anesthesia.Treatment-wise,rats were divided into three groups.In group 1,CSD was covered with a resorbable CM;in group 2,BMSCs were filled in CSD and covered with CM;and in group 3,TCP soaked in BMSCs was placed in CSD and covered with CM.All defects were closed using resorbable sutures.Bone volume and bone mineral density of newly formed bone(NFB)and remaining TCP particles and rate of new bone formation was determined at baseline,2,4,6,and 10 weeks using in vivo m CT.At the 10th week,the rats were killed and calvarial segments were assessed histologically.The results showed that the hardness of NFB was similar to that of the native bone in groups 1 and 2 as compared to the NFB in group 3.Likewise,values for the modulus of elasticity were also significantly higher in group 3 compared to groups 1 and 2.This suggests that TCP when used in combination with BMSCs and without CM was unable to form bone of significant strength that could possibly provide mechanical"lock"between the natural bone and NFB.The use of BMSCs as adjuncts to conventional GBR initiated new bone formation as early as 2 weeks of treatment compared to when GBR is attempted without adjunct BMSC therapy.展开更多
This study aimed to utilize micro-computed tomography(micro-CT)analysis to compare new bone formation in rat calvarial defects using chitosan/fibroin–hydroxyapatite(CFB–HAP)or collagen(Bio-Gide)membranes.Fifty-four(...This study aimed to utilize micro-computed tomography(micro-CT)analysis to compare new bone formation in rat calvarial defects using chitosan/fibroin–hydroxyapatite(CFB–HAP)or collagen(Bio-Gide)membranes.Fifty-four(54)rats were studied.A circular bony defect(8 mm diameter)was formed in the centre of the calvaria using a trephine bur.The CFB–HAP membrane was prepared by thermally induced phase separation.In the experimental group(n518),the CFB–HAP membrane was used to cover the bony defect,and in the control group(n518),a resorbable collagen membrane(Bio-Gide)was used.In the negative control group(n518),no membrane was used.In each group,six animals were euthanized at 2,4 and 8 weeks after surgery.The specimens were then analysed using micro-CT.There were significant differences in bone volume(BV)and bone mineral density(BMD)(P,0.05)between the negative control group and the membrane groups.However,there were no significant differences between the CFB–HAP group and the collagen group.We concluded that the CFB–HAP membrane has significant potential as a guided bone regeneration(GBR)membrane.展开更多
In this study, we successfully constructed a composite of bone marrow mesenchymal stem cells and a chitosan-collagen scaffold in vitro, transplanted either the composite or bone marrow mesenchymal stem cells alone int...In this study, we successfully constructed a composite of bone marrow mesenchymal stem cells and a chitosan-collagen scaffold in vitro, transplanted either the composite or bone marrow mesenchymal stem cells alone into the ischemic area in animal models, and compared their effects. At 14 days after co-transplantation of bone marrow mesenchymal stem cells and the hitosan-collagen scaffold, neurological function recovered noticeably. Vascular endothelial growth factor expression and nestin-labeled neural precursor cells were detected in the ischemic area, surrounding tissue, hippocampal dentate gyrus and subventricular zone. Simultaneously, a high level of expression of glial fibrillary acidic protein and a low level of expression of neuron-specific enolase were visible in Brd U-labeled bone marrow mesenchymal stem cells. These findings suggest that transplantation of a composite of bone marrow mesenchymal stem cells and a chitosan-collagen scaffold has a neuroprotective effect following ischemic stroke.展开更多
An insight into the interaction of collagen type I with apatite in bone tissue was performed by using differential scanning calorimetry, Fourier transform infrared spectroscopy, and molecular modeling. Scanning electr...An insight into the interaction of collagen type I with apatite in bone tissue was performed by using differential scanning calorimetry, Fourier transform infrared spectroscopy, and molecular modeling. Scanning electron microscopy shows that bone organic content incinerate gradually through the different temperatures studied. We suggest that the amide regions of the type I collagen molecule (mainly C=O groups of the peptide bonds) will be important in the control of the interactions with the apatite from bone. The amide I infrared bands of the collagen type I change when interacting to apatite, what might confirm our assumption. Bone tissue results in a loss of thermal stability compared to the collagen studied apart, as a consequence of the degradation and further combustion of the collagen in contact with the apatite microcrystals in bone. The thermal behavior of bone is very distinctive. Its main typical combustion temperature is at 360°C with a shoulder at 550°C compared to the thermal behavior of collagen, with the mean combustion peak at ca. 500°C. Our studies with molecular mechanics (MM+ force field) showed different interaction energies of the collagen-like molecule and different models of the apatite crystal planes. We used models of the apatite (100) and (001) planes;additional two planes (001) were explored with phosphate-rich and calcium-rich faces;an energetic preference was found in the latter case. We preliminary conclude that the peptide bond of collagen type I is modified when the molecule interacts with the apatite, producing a decrease in the main peak from ca. 500°C in collagen, up to 350°C in bone. The combustion might be related to collagen type I, as the ΔH energies present only small variations between mineralized and non-mineralized samples. The data obtained here give a molecular perspective into the structural properties of bone and the change in collagen properties caused by the interaction with the apatite. Our study can be useful to understand the biological synthesis of minerals as well as the organic-inorganic interaction and the synthesis of apatite implant materials.展开更多
Combinations of biomaterials and cells can effectively target delivery of cells or other therapeutic factors to the brain to rebuild damaged nerve pathways after brain injury.Porous collagen-chitosan scaffolds were pr...Combinations of biomaterials and cells can effectively target delivery of cells or other therapeutic factors to the brain to rebuild damaged nerve pathways after brain injury.Porous collagen-chitosan scaffolds were prepared by a freeze-drying method based on brain tissue engineering.The scaffolds were impregnated with rat bone marrow mesenchymal stem cells.A traumatic brain injury rat model was established using the 300 g weight free fall impact method.Bone marrow mesenchymal stem cells/collagen-chitosan scaffolds were implanted into the injured brain.Modified neurological severity scores were used to assess the recovery of neurological function.The Morris water maze was employed to determine spatial learning and memory abilities.Hematoxylin-eosin staining was performed to measure pathological changes in brain tissue.Immunohistochemistry was performed for vascular endothelial growth factor and for 5-bromo-2-deoxyuridine(BrdU)/neuron specific enolase and BrdU/glial fibrillary acidic protein.Our results demonstrated that the transplantation of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds to traumatic brain injury rats remarkably reduced modified neurological severity scores,shortened the average latency of the Morris water maze,increased the number of platform crossings,diminished the degeneration of damaged brain tissue,and increased the positive reaction of vascular endothelial growth factor in the transplantation and surrounding areas.At 14 days after transplantation,increased BrdU/glial fibrillary acidic protein expression and decreased BrdU/neuron specific enolase expression were observed in bone marrow mesenchymal stem cells in the injured area.The therapeutic effect of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds was superior to stereotactic injection of bone marrow mesenchymal stem cells alone.To test the biocompatibility and immunogenicity of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds,immunosuppressive cyclosporine was intravenously injected 12 hours before transplantation and 1-5 days after transplantation.The above indicators were similar to those of rats treated with bone marrow mesenchymal stem cells and collagen-chitosan scaffolds only.These findings indicate that transplantation of bone marrow mesenchymal stem cells in a collagen-chitosan scaffold can promote the recovery of neuropathological injury in rats with traumatic brain injury.This approach has the potential to be developed as a treatment for traumatic brain injury in humans.All experimental procedures were approved by the Institutional Animal Investigation Committee of Capital Medical University,China(approval No.AEEI-2015-035)in December 2015.展开更多
A synthetizing material blended with two distinct proteins (collagen and casein) and mineral mixture, was developed in order to evaluate their properties suitable for possible applications in the biomedical such as in...A synthetizing material blended with two distinct proteins (collagen and casein) and mineral mixture, was developed in order to evaluate their properties suitable for possible applications in the biomedical such as inducing the regeneration of damaged bone, either due to an accident or illness. Samples were evaluated by 1) Mechanical properties tests under the bending, 2) Scanning electronic microscopy and 3) Infrared spectroscopy were carried out. The results showed that the developed material has breaking strength and structure characteristics associated with the protein used in their composition. This fact suggests that the used protein determines the resistance of the material, in such a way according to the required use, being able to choose appropriate strength and duration either short or long time. The material composition for specific use, in order to find the most suitable mixture for bone replacement, or induce bone recovery, according to the required properties similar to those of damaged living tissue.展开更多
目的研究TGF-1β、BM P-2和typeⅡco llagen在退行性腰椎滑脱(degenerative lum bar spondy lo listhes is,DLS)和腰椎间盘突出症(lum bar d isc hern iation,LDH)黄韧带中的表达及其意义。方法37例手术切除的腰椎椎板间部黄韧带标本分...目的研究TGF-1β、BM P-2和typeⅡco llagen在退行性腰椎滑脱(degenerative lum bar spondy lo listhes is,DLS)和腰椎间盘突出症(lum bar d isc hern iation,LDH)黄韧带中的表达及其意义。方法37例手术切除的腰椎椎板间部黄韧带标本分为3组,第1组为退行性腰椎滑脱组(DLS)10例;第2组为腰椎间盘突出症组(LDH)17例,第3组为正常对照组10例,其中7例取自腰椎骨折手术病人,3例取自意外死亡者。应用EnV is ion二步免疫组化的方法检测其TGF-1β、BM P-2和typeⅡco llagen的表达情况,普通光镜观察,计算出各标本的表达阳性率和表达强度,数据以x-±s标准差及表达强度表示,结果分别用Spss统计软件和R id it进行分析。结果TGF-1β、BM P-2和typeⅡco llagen的阳性表达产物见于成纤维细胞、成软骨细胞和软骨细胞中,而Ⅱ型胶原染色还可同时见于基质。TGF-1β、BM P-2和typeⅡco llagen在DLS组中的表达明显高于LDH组和正常组(P<0.01或P<0.05),Ⅱ型胶原基质染色明显深于LDH组和对照组。LDH组的TGF-1β和typeⅡco llagen的表达阳性率和表达强度与正常组之间差异无显著性(P>0.05),而BM P-2的表达阳性率和表达强度在LDH组与正常组之间具有统计学意义(P<0.01)。结论黄韧带所受到的异常机械牵张力可以增加TGF-1β在黄韧带细胞中的合成,而TGF-1β则促进退行性腰椎滑脱黄韧带中的Ⅱ型胶原合成,导致黄韧带的退变和肥厚。BM P-2在退变黄韧带中的表达异常增高,可能与黄韧带的软骨化倾向有关。展开更多
Bone tissue engineering, aiming at developing bone substitutes for repair and regeneration of bone defects instead of using autologous bone grafts,has attracted wide attention in the field of tissue engineering and re...Bone tissue engineering, aiming at developing bone substitutes for repair and regeneration of bone defects instead of using autologous bone grafts,has attracted wide attention in the field of tissue engineering and regenerative medicine.Developing biomimetic biomaterial scaffolds able to regulate osteogenic differentiation of stem cells could be a promising strategy to improve the therapeutic efficacy.In this study, electrospun composite nanofibers of hydroxyapatite / collagen / chitosan( HAp / Col / CTS)resembling the fibrous nanostructure and constituents of the hierarchically organized natural bone,were prepared to investigate their capacity for promoting bone mesenchymal stem cells( BMSCs)to differentiate into the osteogenic lineage in the absence and presence of the osteogenic supplementation, respectively.Cell morphology,proliferation and quantified specific osteogenic protein expression on the electrospun HAp / Col / CTS scaffolds were evaluated in comparison with different controls including electrospun nanofibrous CTS,HAp / CTS and tissue culture plate.Our results showed that the nanofibrous HAp / Col / CTS scaffolds supported better spreading and proliferation of the BMSCs than other substrates( P < 0.01).Expressions of osteogenesis protein markers,alkaline phosphatase( ALP) and Col,were significantly upregulated on the HAp / Col / CTS than those on the CTS( P < 0.01) and HAp /CTS( P < 0.05) scaffolds in the absence of the osteogenic supplementation.Moreover,presence of osteogenic supplementation also proved to enhance osteogenic differentiation of BMSCs on HAp /Col / CTS scaffolds, indicative of a synergistic effect.This study highlights the potential of BMSCs / HAp / Col / CTS cell-scaffold system for functional bone repair and regeneration applications.展开更多
Fibromyalgia (FM) is a complex, chronic condition, which causes widespread musculoskeletal pain, fatigue and a variety of other symptoms. Many polymorphisms related to neuroendocrine system function as the ApoE isofor...Fibromyalgia (FM) is a complex, chronic condition, which causes widespread musculoskeletal pain, fatigue and a variety of other symptoms. Many polymorphisms related to neuroendocrine system function as the ApoE isoforms, Val158Met polymorphism in COMT, as well as a 44 bp deletion located in 5-HTTLPR, have been studied. Other polymorphisms have been related to inflammatory response such as the 70 bp VNTR in IL-4 or to citokine levels. Furthermore, some studies focused on finding out new FM related SNPs, have been performed by genome wide association scan (GWAS). The target of this work was to study a possible linkage of a collagen type I polymorphism (COL1A1 rs180012 SNP) affecting bone mineralization, with fibromyalgia. Results obtained show a clear association of ss homozygous genotype with FM patients no dependent on bone mineralization.展开更多
基金support from the staff of the National Engineering Research Center for Functional Food,Jiangnan Universitysupported by the Postdoctoral Research Funding of Jiangsu Province (2021K269B)National Key Research & Developmental Program of China (2018YFA0900300)。
文摘In this study, yak bone collagen hydrolysate(YBCH)was produced by mixed proteases and provided to standard-diet mice at a different dose(low dose(LD), medium dose(MD), and high dose(HD))to investigate its effects on the composition of gut microbiota and short-chain fatty acids(SCFA)production. It was found that YBCH was mainly composed of small molecular peptides whose molecular weight below 2 000 Da. Notably, supplementation with different doses of YBCH could significantly downregulate the ratio of Firmicutes to Bacteroidetes in the fecal microbiota. At the family level, the Lachnospiraceae abundance was significantly reduced in the YBCH gavage groups(mean reduction ratio 41.7 %, 35.2%, and 36.4% for LD, MD, and HD group, respectively). The predicted functions of gut microbes in the MD group were significantly increased at “lipid metabolism” and “glycan biosynthesis and metabolism”. Moreover, the SCFA production in the YBCH groups was elevated. Especially, the concentration of acetic acid, propionic acid, and butyric acid in the MD group was separately increased 79.7%, 89.2%, and 78.8% than that in the NC group. These results indicated that YBCH might be applied in the development of functional food for intestinal microecological regulation.
基金supported by the National Natural Science Foundation of China(32101883)Fellowship China Postdoctoral Science Foundation(2021M693902)National Agricultural Science and Technology Innovation Project(CAAS-ASTIP-2022)。
文摘Bone collagen hydrolysates(peptides)derived from byproduct of animal product processing have been used to produce commercially valuable products due to their potential antioxidant activity.Maillard glycosylated reaction is considered as a promising method to enhance the antioxidant activity of peptides.Hence,this research aims at investigating the Maillard glycosylation activity and antioxidant activity of bone collagen hydrolysates from different sources.In this study,3 glycosylated bone collagen hydrolysates were prepared and characterized,and cytotoxicity and antioxidant activity were analyzed and evaluated.The free amino groups loss,browning intensity,and fluorescence intensity of G-Cbcp(glycosylated chicken bone collagen hydrolysates(peptides))were the heaviest,followed by G-Pbcp(glycosylated porcine bone collagen hydrolysates(peptides))and G-Bbcp(glycosylated bovine bone collagen hydrolysates(peptides)).The results of amino acid analysis showed that amino acid composition of different bone collagen hydrolysates was significantly different and the amino acid decreased to different degrees after Maillard glycosylated reaction,which may lead to differences in Maillard glycosylated reaction activity.Furthermore,the 3 glycosylated hydrolysates showed no significant cytotoxicity.The results showed that glycosylation process significantly increased the antioxidant activity of bone collagen hydrolysates,and G-Cbcp showed the strongest antioxidant activity,followed by G-Pbcp and G-Bbcp.Therefore,compared with the bone collagen hydrolysates,3 glycosylated hydrolysates showed significant characteristic and structural changes,and higher antioxidant activity.
基金funded by the emarked fund for China Agriculture Research System (CARS-39)the National Agricultural Science and Technology Innovation Program
文摘Ovine bones are the major by-products after slaughtered. The present study was conducted to extract and characterize acid soluble collagens(ASC) and pepsin soluble collagens(PSC) from ovine bones(Ujumuqin sheep). Ovine bones collagen were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) and liquid chromatography-tandem mass spectrometry(LC-MS/MS) as type I collagen. The results of Fourier transform infrared(FTIR) spectra analysis testified the existence of triple superhelical structure in both ASC and PSC, showing pepsin did not disrupt the triple helical structure of ovine bones collagen. Glycine, accounting for one-third of total amino acids, was the major amino acid for ovine bones collagen. Higher imino acid content was responsible for higher thermal denaturation temperature of ovine bones collagen compared to fish collagens. The isoelectric point of ASC was lower than PSC due to the higher content of acidic amino acids. Therefore, this study provides the potential reference for collagen extraction and application of ovine bones by-procduct.
基金King Saud University,through Vice Deanship of Research Chairs
文摘The aim of the present real time in vivo micro-computed tomography(m CT)and histologic experiment was to assess the efficacy of guided bone regeneration(GBR)around standardized calvarial critical size defects(CSD)using bone marrow-derived mesenchymal stem cells(BMSCs),and collagen membrane(CM)with and without tricalcium phosphate(TCP)graft material.In the calvaria of nine female Sprague-Dawley rats,full-thickness CSD(diameter 4.6 mm)were created under general anesthesia.Treatment-wise,rats were divided into three groups.In group 1,CSD was covered with a resorbable CM;in group 2,BMSCs were filled in CSD and covered with CM;and in group 3,TCP soaked in BMSCs was placed in CSD and covered with CM.All defects were closed using resorbable sutures.Bone volume and bone mineral density of newly formed bone(NFB)and remaining TCP particles and rate of new bone formation was determined at baseline,2,4,6,and 10 weeks using in vivo m CT.At the 10th week,the rats were killed and calvarial segments were assessed histologically.The results showed that the hardness of NFB was similar to that of the native bone in groups 1 and 2 as compared to the NFB in group 3.Likewise,values for the modulus of elasticity were also significantly higher in group 3 compared to groups 1 and 2.This suggests that TCP when used in combination with BMSCs and without CM was unable to form bone of significant strength that could possibly provide mechanical"lock"between the natural bone and NFB.The use of BMSCs as adjuncts to conventional GBR initiated new bone formation as early as 2 weeks of treatment compared to when GBR is attempted without adjunct BMSC therapy.
文摘This study aimed to utilize micro-computed tomography(micro-CT)analysis to compare new bone formation in rat calvarial defects using chitosan/fibroin–hydroxyapatite(CFB–HAP)or collagen(Bio-Gide)membranes.Fifty-four(54)rats were studied.A circular bony defect(8 mm diameter)was formed in the centre of the calvaria using a trephine bur.The CFB–HAP membrane was prepared by thermally induced phase separation.In the experimental group(n518),the CFB–HAP membrane was used to cover the bony defect,and in the control group(n518),a resorbable collagen membrane(Bio-Gide)was used.In the negative control group(n518),no membrane was used.In each group,six animals were euthanized at 2,4 and 8 weeks after surgery.The specimens were then analysed using micro-CT.There were significant differences in bone volume(BV)and bone mineral density(BMD)(P,0.05)between the negative control group and the membrane groups.However,there were no significant differences between the CFB–HAP group and the collagen group.We concluded that the CFB–HAP membrane has significant potential as a guided bone regeneration(GBR)membrane.
基金funded by a grant from Shaanxi Provincial Support Project of Scientific Research Development Plan of China,No.2012KCT-16
文摘In this study, we successfully constructed a composite of bone marrow mesenchymal stem cells and a chitosan-collagen scaffold in vitro, transplanted either the composite or bone marrow mesenchymal stem cells alone into the ischemic area in animal models, and compared their effects. At 14 days after co-transplantation of bone marrow mesenchymal stem cells and the hitosan-collagen scaffold, neurological function recovered noticeably. Vascular endothelial growth factor expression and nestin-labeled neural precursor cells were detected in the ischemic area, surrounding tissue, hippocampal dentate gyrus and subventricular zone. Simultaneously, a high level of expression of glial fibrillary acidic protein and a low level of expression of neuron-specific enolase were visible in Brd U-labeled bone marrow mesenchymal stem cells. These findings suggest that transplantation of a composite of bone marrow mesenchymal stem cells and a chitosan-collagen scaffold has a neuroprotective effect following ischemic stroke.
基金the National Autonomous University of Mexico for financial support(grant DGAPA-IN100303)A.H.thanks the National Council of Science and Technology of Mexico(CONACyT)and DAAD for scholarships
文摘An insight into the interaction of collagen type I with apatite in bone tissue was performed by using differential scanning calorimetry, Fourier transform infrared spectroscopy, and molecular modeling. Scanning electron microscopy shows that bone organic content incinerate gradually through the different temperatures studied. We suggest that the amide regions of the type I collagen molecule (mainly C=O groups of the peptide bonds) will be important in the control of the interactions with the apatite from bone. The amide I infrared bands of the collagen type I change when interacting to apatite, what might confirm our assumption. Bone tissue results in a loss of thermal stability compared to the collagen studied apart, as a consequence of the degradation and further combustion of the collagen in contact with the apatite microcrystals in bone. The thermal behavior of bone is very distinctive. Its main typical combustion temperature is at 360°C with a shoulder at 550°C compared to the thermal behavior of collagen, with the mean combustion peak at ca. 500°C. Our studies with molecular mechanics (MM+ force field) showed different interaction energies of the collagen-like molecule and different models of the apatite crystal planes. We used models of the apatite (100) and (001) planes;additional two planes (001) were explored with phosphate-rich and calcium-rich faces;an energetic preference was found in the latter case. We preliminary conclude that the peptide bond of collagen type I is modified when the molecule interacts with the apatite, producing a decrease in the main peak from ca. 500°C in collagen, up to 350°C in bone. The combustion might be related to collagen type I, as the ΔH energies present only small variations between mineralized and non-mineralized samples. The data obtained here give a molecular perspective into the structural properties of bone and the change in collagen properties caused by the interaction with the apatite. Our study can be useful to understand the biological synthesis of minerals as well as the organic-inorganic interaction and the synthesis of apatite implant materials.
基金financially supported by the Postdoctoral Research Foundation of Beijing of China,No.2017-ZZ-120(to FY)the Natural Science Foundation of Beijing of China,No.2164073(to ML)the Beijing Municipal Administration of Hospitals’ Youth Plan of China,No.QML20180804(to ML)
文摘Combinations of biomaterials and cells can effectively target delivery of cells or other therapeutic factors to the brain to rebuild damaged nerve pathways after brain injury.Porous collagen-chitosan scaffolds were prepared by a freeze-drying method based on brain tissue engineering.The scaffolds were impregnated with rat bone marrow mesenchymal stem cells.A traumatic brain injury rat model was established using the 300 g weight free fall impact method.Bone marrow mesenchymal stem cells/collagen-chitosan scaffolds were implanted into the injured brain.Modified neurological severity scores were used to assess the recovery of neurological function.The Morris water maze was employed to determine spatial learning and memory abilities.Hematoxylin-eosin staining was performed to measure pathological changes in brain tissue.Immunohistochemistry was performed for vascular endothelial growth factor and for 5-bromo-2-deoxyuridine(BrdU)/neuron specific enolase and BrdU/glial fibrillary acidic protein.Our results demonstrated that the transplantation of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds to traumatic brain injury rats remarkably reduced modified neurological severity scores,shortened the average latency of the Morris water maze,increased the number of platform crossings,diminished the degeneration of damaged brain tissue,and increased the positive reaction of vascular endothelial growth factor in the transplantation and surrounding areas.At 14 days after transplantation,increased BrdU/glial fibrillary acidic protein expression and decreased BrdU/neuron specific enolase expression were observed in bone marrow mesenchymal stem cells in the injured area.The therapeutic effect of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds was superior to stereotactic injection of bone marrow mesenchymal stem cells alone.To test the biocompatibility and immunogenicity of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds,immunosuppressive cyclosporine was intravenously injected 12 hours before transplantation and 1-5 days after transplantation.The above indicators were similar to those of rats treated with bone marrow mesenchymal stem cells and collagen-chitosan scaffolds only.These findings indicate that transplantation of bone marrow mesenchymal stem cells in a collagen-chitosan scaffold can promote the recovery of neuropathological injury in rats with traumatic brain injury.This approach has the potential to be developed as a treatment for traumatic brain injury in humans.All experimental procedures were approved by the Institutional Animal Investigation Committee of Capital Medical University,China(approval No.AEEI-2015-035)in December 2015.
文摘A synthetizing material blended with two distinct proteins (collagen and casein) and mineral mixture, was developed in order to evaluate their properties suitable for possible applications in the biomedical such as inducing the regeneration of damaged bone, either due to an accident or illness. Samples were evaluated by 1) Mechanical properties tests under the bending, 2) Scanning electronic microscopy and 3) Infrared spectroscopy were carried out. The results showed that the developed material has breaking strength and structure characteristics associated with the protein used in their composition. This fact suggests that the used protein determines the resistance of the material, in such a way according to the required use, being able to choose appropriate strength and duration either short or long time. The material composition for specific use, in order to find the most suitable mixture for bone replacement, or induce bone recovery, according to the required properties similar to those of damaged living tissue.
文摘目的研究TGF-1β、BM P-2和typeⅡco llagen在退行性腰椎滑脱(degenerative lum bar spondy lo listhes is,DLS)和腰椎间盘突出症(lum bar d isc hern iation,LDH)黄韧带中的表达及其意义。方法37例手术切除的腰椎椎板间部黄韧带标本分为3组,第1组为退行性腰椎滑脱组(DLS)10例;第2组为腰椎间盘突出症组(LDH)17例,第3组为正常对照组10例,其中7例取自腰椎骨折手术病人,3例取自意外死亡者。应用EnV is ion二步免疫组化的方法检测其TGF-1β、BM P-2和typeⅡco llagen的表达情况,普通光镜观察,计算出各标本的表达阳性率和表达强度,数据以x-±s标准差及表达强度表示,结果分别用Spss统计软件和R id it进行分析。结果TGF-1β、BM P-2和typeⅡco llagen的阳性表达产物见于成纤维细胞、成软骨细胞和软骨细胞中,而Ⅱ型胶原染色还可同时见于基质。TGF-1β、BM P-2和typeⅡco llagen在DLS组中的表达明显高于LDH组和正常组(P<0.01或P<0.05),Ⅱ型胶原基质染色明显深于LDH组和对照组。LDH组的TGF-1β和typeⅡco llagen的表达阳性率和表达强度与正常组之间差异无显著性(P>0.05),而BM P-2的表达阳性率和表达强度在LDH组与正常组之间具有统计学意义(P<0.01)。结论黄韧带所受到的异常机械牵张力可以增加TGF-1β在黄韧带细胞中的合成,而TGF-1β则促进退行性腰椎滑脱黄韧带中的Ⅱ型胶原合成,导致黄韧带的退变和肥厚。BM P-2在退变黄韧带中的表达异常增高,可能与黄韧带的软骨化倾向有关。
基金the Fundamental Research Funds for the Central Universities,China(No.14D110519)Pujiang Talent Program Funded by the Science and Technology Commission of Shanghai Municipality,China(No.10PJ1400200)National Natural Science Foundation of China(No.51073032)
文摘Bone tissue engineering, aiming at developing bone substitutes for repair and regeneration of bone defects instead of using autologous bone grafts,has attracted wide attention in the field of tissue engineering and regenerative medicine.Developing biomimetic biomaterial scaffolds able to regulate osteogenic differentiation of stem cells could be a promising strategy to improve the therapeutic efficacy.In this study, electrospun composite nanofibers of hydroxyapatite / collagen / chitosan( HAp / Col / CTS)resembling the fibrous nanostructure and constituents of the hierarchically organized natural bone,were prepared to investigate their capacity for promoting bone mesenchymal stem cells( BMSCs)to differentiate into the osteogenic lineage in the absence and presence of the osteogenic supplementation, respectively.Cell morphology,proliferation and quantified specific osteogenic protein expression on the electrospun HAp / Col / CTS scaffolds were evaluated in comparison with different controls including electrospun nanofibrous CTS,HAp / CTS and tissue culture plate.Our results showed that the nanofibrous HAp / Col / CTS scaffolds supported better spreading and proliferation of the BMSCs than other substrates( P < 0.01).Expressions of osteogenesis protein markers,alkaline phosphatase( ALP) and Col,were significantly upregulated on the HAp / Col / CTS than those on the CTS( P < 0.01) and HAp /CTS( P < 0.05) scaffolds in the absence of the osteogenic supplementation.Moreover,presence of osteogenic supplementation also proved to enhance osteogenic differentiation of BMSCs on HAp /Col / CTS scaffolds, indicative of a synergistic effect.This study highlights the potential of BMSCs / HAp / Col / CTS cell-scaffold system for functional bone repair and regeneration applications.
文摘Fibromyalgia (FM) is a complex, chronic condition, which causes widespread musculoskeletal pain, fatigue and a variety of other symptoms. Many polymorphisms related to neuroendocrine system function as the ApoE isoforms, Val158Met polymorphism in COMT, as well as a 44 bp deletion located in 5-HTTLPR, have been studied. Other polymorphisms have been related to inflammatory response such as the 70 bp VNTR in IL-4 or to citokine levels. Furthermore, some studies focused on finding out new FM related SNPs, have been performed by genome wide association scan (GWAS). The target of this work was to study a possible linkage of a collagen type I polymorphism (COL1A1 rs180012 SNP) affecting bone mineralization, with fibromyalgia. Results obtained show a clear association of ss homozygous genotype with FM patients no dependent on bone mineralization.
