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1.
《Acta biomaterialia》2014,10(6):2727-2738
Myocardial infarction (MI) leads to the loss of cardiomyocytes, followed by left ventricular (LV) remodeling and cardiac dysfunction. The authors hypothesize that an elastic, biodegradable nanofibrous cardiac patch loaded with mesenchymal stem cells (MSC) could restrain LV remodeling and improve cardiac function after MI. Poly(ε-caprolactone)/gelatin (PG) nanofibers were fabricated by electrospinning, and the nanofibers displayed a porous and uniform nanofibrous structure with a diameter of 244 ± 51 nm. An MI model was established by ligation of the left anterior descending coronary artery of female Sprague–Dawley rats. The PG nanofibrous patch seeded with MSC, isolated from rat bone marrow, was implanted on the epicardium of the infarcted region of the LV wall of the heart. After transplantation, the PG–cell patch restricted the expansion of the LV wall effectively and reduced the scar size, and the density of the microvessels increased. Cells within the patch were able to migrate towards the scar tissue, and promoted new blood vessel formation at the infarct site. Angiogenesis and the cardiac functions improved significantly after 4 weeks of implantation. The MSC-seeded PG nanofibrous patches are demonstrated to provide sufficient mechanical support, to induce angiogenesis and to accelerate cardiac repair in a rat model of MI. The study highlights the positive impact of implantation of an MSC-seeded PG nanofibrous patch as a novel constituent for MI repair.  相似文献   

2.
Choi JS  Lee SJ  Christ GJ  Atala A  Yoo JJ 《Biomaterials》2008,29(19):2899-2906
Current treatment options for restoring large skeletal muscle tissue defects due to trauma or tumor ablation are limited by the host muscle tissue availability and donor site morbidity of muscle flap implantation. Creation of implantable functional muscle tissue that could restore muscle defects may bea possible solution. To engineer functional muscle tissue for reconstruction, scaffolds that mimic native fibers need to be developed. In this study we examined the feasibility of using poly(epsilon-caprolactone) (PCL)/collagen based nanofibers using electrospinning as a scaffold system for implantable engineered muscle. We investigated whether electrospun nanofibers could guide morphogenesis of skeletal muscle cells and enhance cellular organization. Nanofibers with different fiber orientations were fabricated by electrospinning with a blend of PCL and collagen. Human skeletal muscle cells (hSkMCs) were seeded onto the electrospun PCL/collagen nanofiber meshes and analyzed for cell adhesion, proliferation and organization. Our results show that unidirectionally oriented nanofibers significantly induced muscle cell alignment and myotube formation as compared to randomly oriented nanofibers. The aligned composite nanofiber scaffolds seeded with skeletal muscle cells may provide implantable functional muscle tissues for patients with large muscle defects.  相似文献   

3.
Abstract

In this study, an ideal nano-scale material, named epidermal stimulating (ES) factors-gelatin/polycaprolactone (GT/PCL) nanofiber, was fabricated using a coaxial electrospinning technique. The ES-GT/PCL nanofibers possessed a highly porous structure with qualified mechanical properties for transplantation. With ES factors stored in the core and GT/PCL in the shell, the ES factors could be protected and released in a sustained manner. After seeding L929 cell line on ES-GT/PCL nanofibers for 7?days in vitro, the proliferation of cells was nearly 1.5 folds compared to the control group. The in vivo study showed that ES-GT/PCL nanofibers can accelerate skin wound healing rate during the healing course, especially on the early stage. The epidermal and dermal thickness, as well as skin appendages and fat tissue, were the most similar to the native skin. These findings provided valuable insights into the addition of multiple bioactive factors to nanometre biomaterials, and optimising the advantages of the compositions as a promising potential dermal substitute construct.  相似文献   

4.
A sufficient cell source and minimal invasiveness in obtaining human adipose stromal cells (hASCs) hold great promise for their utilization in wound repair. However, little is known about how cell-residing microenvironments regulate the cellular response. In this study we explored the effects of polycaprolactone (PCL)/collagen nanofibers with distinct spatial arrangements (aligned and random) on phenotypic expression of hASCs in vitro. Elongated cell morphology, higher proliferation, and faster migration rate were observed for hASCs cultured on the aligned nanofibers, showing that hASCs could detect the nanofiber spatial arrangement and then distinctively respond. This study on the expression of extracellular matrix (ECM) related genes in hASCs revealed higher synthesis capacity for critical ECM molecules including tropoelastin, collagen I, and matrix metalloproteinase (MMP)-1 on the aligned nanofibers. Integrins α(5), β(1), β(3), β(6,) and transforming growth factor (TGF)-β(1) were differentially regulated by PCL/collagen nanofiber arrangements. Our results indicate that fiber orientation-induced phenotypic change of hASCs may be regulated by integrins and TGF-β signaling synergistically. These findings demonstrate the potential application of hASCs and aligned PCL/collagen nanofibers for accelerated wound repair.  相似文献   

5.
Ku SH  Lee SH  Park CB 《Biomaterials》2012,33(26):6098-6104
The interactions between cells and materials play critical roles in the success of new scaffolds for tissue engineering, since chemical and physical properties of biomaterials regulate cell adhesion, proliferation, migration, and differentiation. We have developed nanofibrous substrates that possess both topographical cues and electroactivity. The nanofiber scaffolds were fabricated through the electrospinning of polycaprolactone (PCL, a biodegradable polymer) and polyaniline (PANi, a conducting polymer) blends. We investigated the ways in which those properties influenced myoblast behaviors. Neither nanofiber alignment nor PANi concentration influenced cell growth and proliferation, but cell morphology changed significantly from multipolar to bipolar with the anisotropy of nanofibers. According to our analyses of myosin heavy chain expression, multinucleate myotube formation, and the expression of differentiation-specific genes (myogenin, troponin T, MHC), the differentiation of myoblasts on PCL/PANi nanofibers was strongly dependent on both nanofiber alignment and PANi concentration. Our results suggest that topographical cues and the electroactivity of nanofibers synergistically stimulate muscle cell differentiation to make PCL/PANi nanofibers a suitable scaffold material for skeletal tissue engineering.  相似文献   

6.
Choi JS  Leong KW  Yoo HS 《Biomaterials》2008,29(5):587-596
Biodegradable polymers were electrospun and recombinant human epidermal growth factor (EGF) was immobilized on the electrospun nanofibers for the purpose of treating diabetic ulcers. Amine-terminated block copolymers composed of poly(epsilon-caprolactone) [PCL] and poly(ethyleneglycol) [PEG] and PCL were electrospun to biocompatible nanofibers with functional amine groups on the surface via PEG linkers. EGF was chemically conjugated to the surface of the nanofibers. The conjugation amount of EGF on the nanofibers was quantitated by X-ray photoelectron scattering. Human primary keratinocytes were cultivated on EGF-conjugated nanofibers in order to investigate the effect of EGF nanofibers on the differentiation of keratinocytes. Wound healing effects of the EGF nanofibers were confirmed in diabetic animals with dorsal wounds. The expression of keratinocyte-specific genes significantly increased with application of EGF-conjugated nanofibers. The EGF-nanofibers exerted superior in vivo wound healing activities compared to control groups or EGF solutions. Furthermore, immunohistochemical-staining results showed that EGF-receptor (EGFR) was highly expressed in the EGF nanofiber group. This study showed that EGF-conjugated nanofiber could potentially be employed as a novel wound healing material by increasing proliferation and phenotypic expression of keratinocytes.  相似文献   

7.
Ma Z  He W  Yong T  Ramakrishna S 《Tissue engineering》2005,11(7-8):1149-1158
We modified the surface of electrospun poly(caprolactone) (PCL) nanofibers to improve their compatibility with endothelial cells (ECs) and to show the potential application of PCL nanofibers as a blood vessel tissue-engineering scaffold. Nonwoven PCL nanofibers (PCL NF) and aligned PCL nanofibers (APCL NF) were fabricated by electrospinning technology. To graft gelatin on the nanofiber surface, PCL nanofibers were first treated with air plasma to introduce -COOH groups on the surface, followed by covalent grafting of gelatin molecules, using water-soluble carbodiimide as the coupling agent. The chemical change in the material surface during surface modification was confirmed by X-ray photoelectron spectroscopy and quantified by colorimetric methods. ECs were cultured to evaluate the cytocompatibility of surface-modified PCL NF and APCL NF. Gelatin grafting can obviously enhance EC spreading and proliferation compared with the original material. Moreover, gelatin-grafted APCL NF readily orients ECs along the fibers whereas unmodified APCL NF does not. Immunostaining micrographs showed that ECs cultured on gelatin-grafted PCL NF were able to maintain the expression of three characteristic markers: platelet-endothelial cell adhesion molecule 1 (PECAM-1), intercellular adhesion molecule 1 (ICAM-1), and vascular cell adhesion molecule 1 (VCAM-1). The surface-modified PCL nanofibrous material is a potential candidate material in blood vessel tissue engineering.  相似文献   

8.
Human adipose-derived stem cells (hASCs) are an abundant cell source capable of osteogenic differentiation, and have been investigated as an autologous stem cell source for bone tissue engineering applications. The objective of this study was to determine if the addition of a type-I collagen sheath to the surface of poly(ε-caprolactone) (PCL) nanofibers would enhance viability, proliferation and osteogenesis of hASCs. This is the first study to examine the differentiation behavior of hASCs on collagen–PCL sheath–core bicomponent nanofiber scaffolds developed using a co-axial electrospinning technique. The use of a sheath–core configuration ensured a uniform coating of collagen on the PCL nanofibers. PCL nanofiber scaffolds prepared using a conventional electrospinning technique served as controls. hASCs were seeded at a density of 20 000 cells/cm2 on 1 cm2 electrospun nanofiber (pure PCL or collagen–PCL sheath–core) sheets. Confocal microscopy and hASC proliferation data confirmed the presence of viable cells after 2 weeks in culture on all scaffolds. Greater cell spreading occurred on bicomponent collagen–PCL scaffolds at earlier time points. hASCs were osteogenically differentiated by addition of soluble osteogenic inductive factors. Calcium quantification indicated cell-mediated calcium accretion was approx. 5-times higher on bicomponent collagen–PCL sheath–core scaffolds compared to PCL controls, indicating collagen–PCL bicomponent scaffolds promoted greater hASC osteogenesis after two weeks of culture in osteogenic medium. This is the first study to examine the effects of collagen–PCL sheath–core composite nanofibers on hASC viability, proliferation and osteogenesis. The sheath–core composite fibers significantly increased calcium accretion of hASCs, indicating that collagen–PCL sheath–core bicomponent structures have potential for bone tissue engineering applications using hASCs.  相似文献   

9.
BACKGROUND:Mesenchymal stem cells can be used to treat a variety of injuries, but little is known about their effect on systolic hypertension. OBJECTIVE:To study the therapeutic effect of bone marrow mesenchymal stem cells on systolic hypertension rats. METHODS:Twenty-four rats were randomized equally into control, model and cell transplantation groups. A rat model of systolic hypertension was made by injection of vitamin K and warfarin sodium in the model and cell transplantation groups. Rats in the cell transplantation group were given injection of bone marrow mesenchymal stem cells into the left ventricle, while those in the other two groups given normal saline. RESULTS AND CONCLUSION:Compared with the model group, bone marrow mesenchymal stem cells could reduce left ventricular mass index, increase cardiac tissue type I collagen volume fraction, collagen volume fraction and perivascular collagen volume fraction, but the ratio of end-diastolic volume/body weight did not change significantly. These findings indicate that bone marrow mesenchymal stem cell transplantation can reduce myocardial hypertrophy and cardiac fibrosis in systolic hypertension rats.  相似文献   

10.
目的 探讨自聚肽纳米纤维支架承载骨髓源性心肌干细胞(MCSC)移植对大鼠心肌梗死后心功能恢复的影响,寻找一种更适合承载心肌干细胞治疗心肌梗死的可注射性生物材料.方法 通过单细胞克隆培养技术,从骨髓间充质干细胞中筛选具有心肌特异分化潜能的MCSC,固相合成自聚多肽.将雌性大鼠心肌梗死模型随机分为3组:对照组、MCSC移植...  相似文献   

11.
Cellular transplantation represents a promising therapy for myocardial infarction (MI). However, it is limited by low transplanted cell retention and survival within the ischemic tissue. This study was designed to investigate whether injectable α-cyclodextrin/poly(ethylene glycol)–b-polycaprolactone-(dodecanedioic acid)-polycaprolactone–poly(ethylene glycol) (MPEG–PCL–MPEG) hydrogel could improve cell transplant retention and survival, reduce infarct expansion and inhibit left ventricle (LV) remodeling. Bone marrow-derived stem cells (BMSCs) were encapsulated in α-cyclodextrin/MPEG–PCL–MPEG hydrogel and maintained their morphologies during the cell culturing. MTT assays were used for in vitro cell viability studies of the hydrogel and were shown to be non-cytotoxic. Seven days after MI, 100 μl of α-cyclodextrin solution containing 2 × 107 BMSCs and 100 μl of MPEG–PCL–MPEG solution were injected into the infarcted myocardium simultaneously and the solutions solidified immediately. Injection of culture medium or cell alone served as controls. Four weeks after treatment, histological analysis indicated that the hydrogel was absorbed, and the injection of BMSCs with hydrogel had increased cell retention and vessel density around the infarct, and subsequently prevented scar expansion compared with BMSCs injection alone. Echocardiography studies showed that injection of BMSCs with hydrogel increased the LV ejection function and attenuated left ventricular dilatation. This study indicated that the injection of BMSCs with α-cyclodextrin/MPEG–PCL–MPEG hydrogel was an effective strategy which could enhance the effect of cellular transplantation therapy for myocardial infarction.  相似文献   

12.
This study investigated the effect of treatment wientry isosorbide dinitrate (Isoket) on bone mesenchymal stem cell (BMSC) transplantation in a rat model of myocardial infarction (MI) and its possible mechanism. Sprague-Dawley (SD) rats were randomized to a sham operation group, MI control group, BMSC transplantation group, and Isoket-BMSCs transplantation group. Isosorbide dinitrate (Isoket, 5?μg/m) was administered by intraperitoneal injection (10?ml/kg) at 0, 12, and 24?hours following ischemia/reperfusion induction of MI models. Left ventricular function, myocardial infarct size (MIS), the survival of engrafted BMSCs, and expression of vascular endothelial growentry factor (VEGF), inducible nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS) proteins were detected 2?weeks post-transplantation. The results showed isosorbide dinitrate attenuated cardiac dysfunction, increased the survival of engrafted cells in the ischemic heart and promoted iNOS, eNOS, and VEGF protein expression. It is suggested that isosorbide dinitrate enhances mesenchymal stem cell therapy for MI via an eNOS-dependent mechanism.  相似文献   

13.
An efficient and practical ex vivo expansion methodology for human hematopoietic stem/progenitor cells (HSPCs) is critical in realizing the potential of HSPC transplantation in treating a variety of hematologic disorders and as a supportive therapy for malignant diseases. We report here an expansion strategy using a three-dimensional (3D) scaffold conjugated with an extracellular matrix molecule, fibronectin (FN), to partially mimic the hematopoietic stem cell niche. FN-immobilized 3D polyethylene terephthalate (PET) scaffold was synthesized and evaluated for HSPC expansion efficiency, in comparison with a FN-immobilized 2D PET substrate and a 3D scaffold with FN supplemented in the medium. Covalent conjugation of FN produced substrate and scaffold with higher cell expansion efficiency than that on their unmodified counterparts. After 10 days of culture in serum-free medium, human umbilical cord blood CD34+ cells cultured in FN-conjugated scaffold yielded the highest expansion of CD34+ cells (approximately 100 fold) and long-term culture initiating cells (approximately 47-fold). The expanded human CD34+ cells successfully reconstituted hematopoiesis in NOD/SCID mice. This study demonstrated the synergistic effect between the three-dimensionality of the scaffold and surface-conjugated FN, and the potential of this FN-conjugated 3D scaffold for ex vivo expansion of HSPCs.  相似文献   

14.
Polymeric nanofibers fabricated via electrospinning are regarded as promising scaffolds for biomimicking a native extracellular matrix. However, electrospun scaffolds have poor porosity, resulting in cells being unable to infiltrate into the scaffolds but grow only on its surface. In this study, we modified regular electrospinning into rotating multichannel electrospinning (RM-ELSP) to produce microparticles and nanofibers simultaneously. Gelatin nanofibers (0.1–1 μm) and polycaprolactone (PCL) microparticles (0.5–10 μm) were formed and well-mixed. Adjusting the concentration of PCL and/or gelatin, we can fabricate various microparticles/nanofibers composites with different sizes of PCL particles and different diameters of gelatin nanofibers depending on their concentrations (2–10%) during electrospinning. Using PCL particles as a pore generator, we obtained gelatin nanofiber scaffolds with controllable pore size and porosity. Cells adhere and grow into the scaffold easily during in vitro cell culture.  相似文献   

15.
《Acta biomaterialia》2014,10(7):2996-3006
Cardiac tissue engineering approaches can deliver large numbers of cells to the damaged myocardium and have thus increasingly been considered as a possible curative treatment to counteract the high prevalence of progressive heart failure after myocardial infarction (MI). Optimal scaffold architecture and mechanical and chemical properties, as well as immune- and bio-compatibility, need to be addressed. We demonstrated that radio-frequency plasma surface functionalized electrospun poly(ɛ-caprolactone) (PCL) fibres provide a suitable matrix for bone-marrow-derived mesenchymal stem cell (MSC) cardiac implantation. Using a rat model of chronic MI, we showed that MSC-seeded plasma-coated PCL grafts stabilized cardiac function and attenuated dilatation. Significant relative decreases of 13% of the ejection fraction (EF) and 15% of the fractional shortening (FS) were observed in sham treated animals; respective decreases of 20% and 25% were measured 4 weeks after acellular patch implantation, whereas a steadied function was observed 4 weeks after MSC-patch implantation (relative decreases of 6% for both EF and FS).  相似文献   

16.
背景:人脐血间充质干细胞移植治疗肝硬化的可行性及机制有待深入探讨。 目的:观察经门静脉移植人脐血间充质干细胞对肝硬化大鼠肝功能及组织病理学改变的影响。 方法:采用四氯化碳法制备肝硬化大鼠模型,造模成功后,细胞移植组经门静脉注射1 mL BrdU标记的人脐血间充质干细胞(5×106个),模型组注射等体积的PBS;以经门静脉移植1 mL人脐血间充质干细胞的正常大鼠作为对照。细胞移植后4周,取大鼠尾静脉血及肝脏组织进行检测。 结果与结论:细胞移植后4周,与模型组比较,细胞移植组大鼠血清谷丙转氨酶、谷草转氨酶、总胆红素明显降低,而白蛋白明显升高(P < 0.01);肝细胞炎性坏死、脂肪变及肝纤维化程度明显改善(P < 0.05或P < 0.01)。免疫组化及免疫荧光染色显示细胞移植组和对照组大鼠肝组织中均有人脐血间充质干细胞的定植,但细胞移植组BrdU阳性细胞数目明显多于对照组。RT-PCR检测结果显示,细胞移植组大鼠肝组织表达人源性细胞角蛋白18和白蛋白mRNA,而模型组未见。可见人脐血间充质干细胞移植可在一定程度上改善肝硬化大鼠的肝功能及病理损伤,其机制可能与移植细胞在肝硬化大鼠肝内归巢定植并向肝样细胞分化有关。  相似文献   

17.
Natural and synthetic biodegradable nanofibers are extensively used for biomedical applications and tissue engineering. Biocompatibility and a well-established safety profile for polycaprolactone (PCL) and collagen represent a favorable matrix for preparing a dermal substitute for engineering skin. Collagen synthesized by fibroblasts is a good surface active agent and demonstrates its ability to penetrate a lipid-free interface. During granulation tissue formation, fibronectin provides a temporary substratum for migration and proliferation of cells and provides a template for collagen deposition, which increases stiffness and tensile strength of this healing tissues. The objective of this study was to fabricate nanofiber matrices from novel biodegradable PCL and collagen to mimic natural extracellular matrix (ECM) and to examine the cell behavior, cell attachment, and interaction between cells and nanofiber matrices. Collagen nanofiber matrices show a significant (p < 0.001) level of fibroblast proliferation and increase up to 54% compared with control tissue culture plate (TCP) after 72 h. The present investigation shows that PCL-coated collagen matrices are suitable for fibroblast growth, proliferation, and migration inside the matrices. This novel biodegradable PCL and collagen nanofiber matrices support the attachment and proliferation of human dermal fibroblasts and might have potential in tissue engineering as a dermal substitute for skin regeneration.  相似文献   

18.
Synthetic grafts comprised of a porous scaffold in the size and shape of the natural tracheobronchial tree, and autologous stem cells have shown promise in the ability to restore the structure and function of a severely damaged airway system. For this specific application, the selected scaffold material should be biocompatible, elicit limited cytotoxicity, and exhibit sufficient mechanical properties. In this research, we developed composite nanofibers of polycaprolactone (PCL) and depolymerized chitosan using the electrospinning technique and assessed the properties of the fibers for its potential use as a scaffold for regenerating tracheal tissue. Water-soluble depolymerized chitosan solution was first prepared and mixed with polycaprolactone solution making it suitable for electrospinning. Morphology and chemical structure analysis were performed to confirm the structure and composition of the fibers. Mechanical testing of nanofibers demonstrated both elastic and ductile properties depending on the ratio of PCL to chitosan. To assess biological potential, porcine tracheobronchial epithelial (PTBE) cells were seeded on the nanofibers with composition ratios of PCL/chitosan: 100/0, 90/10, 80/20, and 70/30. Transwell inserts were modified with the nanofiber membrane and cells were seeded according to air–liquid interface culture techniques that mimics the conditions found in the human airways. Lactase dehydrogenase assay was carried out at different time points to determine cytotoxicity levels within PTBE cell cultures on nanofibers. This study shows that PCL/chitosan nanofiber has sufficient structural integrity and serves as a potential candidate for tracheobronchial tissue engineering.  相似文献   

19.
Cell therapy has emerged as an attractive therapeutic modality to treat myocardial infarction (MI) via repairing damaged myocardium, and mesenchymal stem cells (MSCs) are an appealing therapeutic approach for cardiac regeneration. However, the clinical application of MSC-based therapy is restricted because of the poor survival of implanted cells, and this poor survival remains poorly understood. Using a tumor necrosis factor (TNF)-α-induced bone marrow (BM)-MSC injury model in vitro and a rat MI model in vivo, we showed in the current study that miR-23a was involved in TNF-α-induced BM-MSC apoptosis through regulating caspase-7 and that the injection of BM-MSCs overexpressing miR-23a could improve left ventricular (LV) function and reduce infarct size in the rat MI model. Our findings elucidate the etiology of MI and provide an alternative treatment strategy for patients with heart failure caused by MI who are not optimal candidates for surgical treatment.  相似文献   

20.
背景:骨髓间充质干细胞移植入缺血心肌后梗死区周边心肌的缺血、缺氧、炎性反应、细胞凋亡等病理变化严重影响到移植骨髓间充质干细胞的存活,而高压氧能显著改善其缺氧状态。 目的:对心肌梗死模型大鼠缺血心肌局部移植血管内皮生长因子修饰的骨髓间充质干细胞,在移植后对大鼠进行高压氧干预,探讨其对骨髓间充质干细胞移植后所获得的治疗性血管生成效应的影响。 方法:将真核表达载体pcDNA3.1(-)/人血管内皮生长因子165转染大鼠骨髓间充质干细胞,再移植至心肌梗死模型大鼠的缺血区组织,移植前细胞行CM-DiI标记。移植后2周每日对大鼠行高压氧治疗干预。移植1个月后行心脏B超测量其左室射血分数,组织化学苏木精-伊红染色和Ⅷ因子染色并评价新生血管密度。 结果与结论:CM-DiI能有效标记骨髓间充质干细胞,标记率近100%。细胞移植1个月后高压氧干预的大鼠射血分数、再生血管密度较均明显增高(P < 0.05)。证实,高压氧干预能显著促进移植血管内皮生长因子基因修饰的骨髓间充质干细胞的心肌梗死大鼠所获得的治疗性血管生成作用,对心脏功能有明显改善作用。  相似文献   

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