Objective To investigate the biocompatibility of p(3HB-co-3HH) and marrow mesenchymal stell cells (MSCs).Methods MSCs were inoculated to p(3HB-co-3HH), and then cultured for 2-4 weeks in vitro and embedded for 2 weeks in vivo. The growth, proliferation, morphology and phenotype properties of MSCs were observed by use of phase contrast microscope, electron microscope, HE staining and staining of type Ⅰ collagen. Results p(3HB-co-3HH) hadgood compatibility. The inoculated MSCs could be well-distributed, attached well and obtain the phenotype of MSCs in p(3HB-co-3HH). After osteogenic inducer were added, MSCs differentiated to osteoblasts and secreted matrix. Type Ⅰ collagen was stained positively by immunohistochemical techenique. Conclusion The above results demonstrate that there is satisfactory biocompatibility betweenp(3HB-co-3HH) and MSCs.
Compare the effect of different chemical methods for preparation of acellular nerve scaffold and to provide an effective nerve scaffold for tissue engineering. Methods Fifteen male SD rats of 2 months old, weighing 200-250 g were selected; the bilateral sciatic nerves were harvested and divided into 3 groups according to preparation methods: group A (normal nerve), group B (Sondell method) and group C (optimal method by Triton X-200, SB-10 and SB-16). The morphology was compared by HE, immunohistochemistry and SEM after dispose; the degrees of decellularization, degrees of demyel ination and integrity of the nerve fiber tube were assessed by scoring system. Results HE staining: In group A, thecross section of nerve was roundness, the cell nuclei was dark blue and the myel in sheath was reticular structure. In group B, the axon and cell nuclei disappeared and the structure of endoneurium was destroyed. In group C, the axon and cell nuclei disappeared and the endoneurium become anomal istic round cavum. The immunohistochemistry staining of Laminin: In group A, the myel in sheath was surrounded by basement membrane with dark blue SC nuclei inside. In group B, the myel in sheath and SC nuclei disappeared and the structure of basement membrane destroyed. In group C, the myel in sheath and SC nuclei disappeared and basement membrane become anomal istic round cavum. The immunohistochemistry staining of S-100: In group A, the myel in sheath and SC were brown. In groups B and C, there were no apparent stained myel in sheath. SEM: In group A, the myel in sheath and axon were clear. In group B, the axon and myel in sheath disappeared and basement membrane became anomal istic. In group C, the basement membrane was more regular than that of group B. The degrees of acellularization and demyel ination of groups B and C were superior to that of group A (P lt; 0.05), and the degrees of demyel ination of group C were superior to that of group B (P lt; 0.05). The integrity of nerve fiber tube of group C was superior to that of group B (P lt; 0.05) and similar to that of group A (P gt; 0.05). The total score was the lowest in group C but the qual ity was the best. Conclusion The effect of decellularization of optimal method was similar to that of traditional Sondell method, but the effect of demyel ination and integrity of nerve fiber tube were better than that of traditional Sondell method. And this acellular nerve can be used as a new kind of nerve scaffold material.
To evaluate the cytocompatibil ity of Arg-Gly-Asp-recombinant spider silk protein (pNSR16) / poly vinyl alcohol (PVA) through in vitro cytotoxicity experiment and cell-material co-culture experiment. Methods pNSR16/PVA scaffold and its extraction were prepared by using solvent casting/particulate leaching method, and NIH-3T3 cells were cultivated with the extraction in vitro. The cytotoxicity of scaffold was analyzed using MTT assay 1, 3 and 5 days after culture. Scanning electron microscope and HE staining observation were conducted 2, 4 and 6 days after culturing NIH-3T3 cells on the pNSR16/PVA scaffold. Immunohistochemistry detection was performed 6 days after co-culture. Adhesion, growthand expression of the cells on the scaffold were observed. Results The cytotoxicity of pNSR16/PVA scaffold was in grade 0. Scanning electron microscope observation: the cells covered the surface of the scaffold and were arranged in a directional manner 4 days after co-culture. HE staining: the cells adhered to and grew on the surface of scaffold, and migrated into the scaffold with the increase of culture duration. Immunohistochemistry detection: bFGF was secreted by NIH-3T3 cells, and the cells differentiated normally. Conclusion pNSR16/PVA scaffold has a satisfactory cytocompatibil ity and may be an ideal tissue engineered scaffold materia
ObjectiveTo assess the role and effect of Wharton's jelly of human umbilical cord oriented scaffold on chondrocytes co-cultured in vitro. MethodsChondrocytes from shoulder cartilage of adult New Zealand rabbits were isolated,cultured,amplified,and labelled using fluorescent dye PKH26.Cells were extracted from human umbilical cord tissue using wet-grinding chemical technology to prepare the Wharton's jelly of human umbilical cord oriented scaffold by freeze-drying and cross-linking technology.Second generation of chondrocytes were cultured with Wharton's jelly of human umbilical cord oriented scaffold.Inverted microscope and scanning electron microscope (SEM) were used to observe the cell distribution and adhesion on the scaffold; extracellular matrix secretion of the chondrocytes were observed by toluidine blue and safranin O staining.Cells distribution and proliferation on the scaffold were assessed by fluorescein diacetate-propidium iodide (FDA-PI) and Hoechst33258 staining.The viability of the in vitro cultured and PKH26 fluorescence labelled chondrocytes on the scaffold were assessed via fluorescence microscope. ResultsInverted microscope showed that the cells cultured on the scaffold for 3 days were round or oval shaped and evenly distributed into space of the scaffold.SEM observation showed that large number of cultured cells adhered to the pores between the scaffolds and were round or oval shape,which aggregated,proliferated,and arranged vertically on longitudinally oriented scaffold at 7 days after culture.Histological observation showed that cells distributed and proliferated on the scaffold,and secreted large amount of extracellular matrix at 7 days.Scaffold could guide cell migration and proliferation,and could effectively preserve and promote the secretion of extracellular matrix.Cell viability assessments at 3 days after culture showed most of the adhered cells were living and the viability was more than 90%.PKH26 labelled chondrocytes were seen,which distributed uniformly along the pore of oriented scaffold,and exuberantly proliferated. ConclusionWharton's jelly of human umbilical cord oriented scaffold favors adhesion,proliferation,and survival of chondrocytes.It possesses a favorable affinity and cell compatibility.Thus,it is an ideal scaffold for cartilage tissue engineering.
ObjectiveTo review the application of silk fibroin scaffold in bone tissue engineering. MethodsThe related literature about the application of silk fibroin scaffold in bone tissue engineering was reviewed, analyzed, and summarized. ResultsSilk fibroin can be manufactured into many types, such as hydrogel, film, nano-fiber, and three-dimensional scaffold, which have superior biocompatibility, slow biodegradability, nontoxic degradation products, and excellent mechanical strength. Meanwhile these silk fibroin biomaterials can be chemically modified and can be used to carry stem cells, growth factors, and compound inorganic matter. ConclusionSilk fibroin scaffolds can be widely used in bone tissue engineering. But it still needs further study to prepare the scaffold in accordance with the requirement of tissue engineering.
Objective To review the fundamental research and the experimental study in the nerve tissue engineering of self-assembl ing peptide nanofiber scaffold (SAPNS). Methods The l iterature concerning basic and experimental studies on SAPNS in the nerve tissue engineering was extensively reviewed. Results SAPNS can promote the neural stem cell adhesion,prol iferation, differentiation and neuron axon outward growth and extension, promote extracellular matrix synthesis and inhibit gl ial cell adhesion and differentiation, and simulate the environment of a cell in the body. Conclusion SAPNS is an ideal matrix material and provides a new way for the repair of nerve tissue injury.
Objective To prepare a spider silk protein bilayer small diameter vascular scaffold using electrospinning, and to observe the blood compatibility in vitro. Methods The Arg-Gly-Asp-recombinant spider silk protein (pNSR16), polycaprolactone (PCL), gelatin (Gt), and heparin (Hep) were blended. Spider silk protein bilayer small diameter vascular scaffold (experimental group) was prepared by electrospinning, with pNSR16 ∶ PCL ∶ Hep (5 ∶ 85 ∶ 10, W/W) hybrid electrospun solution as inner spinning solution and pNSR16 ∶ PCL ∶ Gt (5 ∶ 85 ∶ 10, W/W) hybrid electrospun solution as outer spinning solution, but pNSR16 ∶ PCL (5 ∶ 85, W/W) hybrid electrospun solution was used as inner spinning solution in control group. The scaffold structure of experimental group was observed under scanning electron microscope (SEM); and the hemolysis rate, recalcification clotting time, dynamic clotting time, platelet adhesion, and platelet activation in vitro were compared between 2 groups. Results SEM results showed that bilayer fibers of scaffold were quite different in experimental group; the diameter distribution of inner layer fibers was relatively uniform with small pores, however diameter difference of the outer layer fiber was relatively big with big pores. The contact angle, hemolysis rate, recalcification clotting time, and P-selectin expression of scaffold were (35 ± 3) ° , 1.2% ± 0.1%, (340 ± 11) s, and 0.412 ± 0.027 respectively in experimental group, and were (70 ± 4) ° , 1.9% ± 0.1%, (260 ± 16) s, and 0.678 ± 0.031 respectively in control group; significant difference were found in indexes between 2 groups (P lt; 0.05). With the extension of time, the curve of coagulation time in experimental group sloped downward slowly and had a long time; the blood clotting index values before 30 minutes were significantly higher than those in control group (P lt; 0.05). Platelet adhesion test showed that the scaffold surface almost had no platelet adhesion in experimental group. Conclusion The spider silk protein bilayer small diameter vascular scaffold could be prepared through electrospinning, and it has good blood compatibility in vitro.
Objective To investigate the effects of allogenic transplantation of acellular muscle bioscaffolds (AMBS) seeded with bone marrow mesenchymal stem cells (BMSCs) on the repair of acute hemi-transection spinal cord injury (SCI) in rats. Methods AMBS were prepared by reformed chemical approach and sterilized by compound cold sterilization; BMSCs were harvested by density gradient centrifugation and cultured with adherent method. The 3rd generation BMSCs labeled by Hoechst 33342 were injected into AMBS to construct the BMSCs-AMBS composite scaffolds; the biocompatibility was observed under scanning electron microscope (SEM) and fluorescence microscope in vitro at 14 days. Forty-eight adult female Sprague Dawley rats were used to build SCI model by hemi-transecting at T9-11 level, then randomly divided into 4 groups (n=12). Defects were repaired with BMSCs-AMBS composite scaffolds, BMSCs, and AMBS in groups A, B, and C, respectively; group D was blank control by injecting PBS. At 1, 2, 3, and 4 weeks after surgery, the functional recovery of the hind limbs was evaluated by the Basso-Beattie-Bresnahan (BBB) locomotor rating score. At 4 weeks after surgery, HE staining and immunofluorescent assay were adopted. Results Masson staining and HE staining showed that AMBS was mainly of the collagen fibers in parallel arrange, without muscle fibers. After 14 days of BMSCs and AMBS co-culture, a large number of survival BMSCs labeled by Hoechst 33342 were seen under fluorescence microscope; SEM showed that BMSCs grew and attached to the inner surfaces of AMBS. At 2-4 weeks, the BBB score in group A was significantly higher than that in groups B, C, and D (P lt; 0.05), and it was significantly lower in group D than in the other 3 groups (P lt; 0.05); at 4 weeks, the BBB score in group B was significantly higher than that in group C (t=10.352, P=0.000). HE staining revealed that the area of spinal cord cavity after SCI was markedly smaller in group A than in the other 3 groups; immunofluorescent assay showed that more neurofilament 200 positive fibers and Nestin positive cells were detected in group A than in groups B, C, and D, but glial fibrillary acidic protein (GFAP) positive cells significantly decreased. The integral absorbance (IA) values of GFAP were 733.01 ± 202.04, 926.42 ± 59.46, 1 069.37 ± 33.42, and 1 469.46 ± 160.53 in groups A, B, C, and D, respectively; the IA value of group A was significantly lower than that of groups B, C, and D (P lt; 0.05), and it was significantly higher in group D than in groups A, B, and C (P lt; 0.05). Conclusion With relatively regular internal structures and good biocompatibility, AMBS can inhibit glial scar and enhance the survival, migration, and differentiation of BMSCs, so AMBS is the ideal nature vector for cell transplantation. Co-transplantation of AMBS and BMSCs has synergistic effect in treating SCI, it can promote rat motor function recovery.
Cryogels are a type of hydrogel material which are fabricated by cryopolymerization at subzero temperature. Due to their unique macroporous structure, shape memory properties and injectability, cryogels have gained significant interest in the fields of tissue engineering for encouraging the repair and regeneration of injured tissues. In this review, the basic concepts relevant to cryogels are introduced, and then the fabrication principle, the process parameters and the unique properties of cryogel are discussed. Next, the latest advances of cryogels as three-dimensional scaffold for various tissue engineering applications are given. Finally, this review summarizes the current limitations of cryogels, and strategies to further improve their properties for tissue engineering. The purpose of this article is to provide a reference guide for the researchers in related fields.
ObjectiveTo summarize clinical experience and curative effect in applying three-dimensional mechanical equilibrium concept to cartilage scaffold construction in total auricular reconstruction.MethodsBetween June 2015 and June 2017, ninety-seven microtia patients (102 ears) were treated with total ear reconstruction by using tissue expanders. The patients included 43 males and 54 females and their age ranged from 7 to 45 years with an average of 14 years. There were 92 unilateral cases (45 in left side and 47 in right side) and 5 bilateral ones. There were 89 congenital cases and 8 secondary cases. According to microtia classification criteria, there were 21 cases of type Ⅱ, 67 cases of type Ⅲ, and 9 cases of type Ⅳ. Tissue expander was implanted in the first stage. In the second stage, autogenous cartilage was used to construct scaffolds which were covered by enlarged flap. According to the three-dimensional mechanical equilibrium concept, the stable ear scaffold was supported by the scaffolds base, the junction of helix and inferior crura of antihelix, and helix rim. The reconstructed ears were repaired in the third stage operation.ResultsAll patients had undergone ear reconstruction successfully and all incisions healed well. No infection, subcutaneous effusion, or hemorrhage occurred after operation. All skin flaps, grafts, and ear scaffolds survived completely. All patients received 5- to 17-month follow-up time (mean, 11.3 months) and follow-up time was more than 12 months in 61 cases (64 ears). All reconstructed ears stood upright, and subunits structure and sensory localization of reconstructed ears were clear, and the position, shape, size, and height of bilateral ears were basically symmetrical. Mastoid region scar hyperplasia occurred in 3 patients, which was relieved by anti-scar drugs injection. No scaffolds exposure, absorption, or structural deformation occurred during follow-up period.ConclusionApplication of three-dimensional mechanical equilibrium concept in cartilage scaffold construction can reduce the dosage of costal cartilage, obtain more stable scaffold, and acquire better aesthetic outcomes.