rough the ultramicroscopic observation on muscle and microcirculation, Group A,where a largeamount of DXM combined with heporin was given svstematically and locally into the femoral artery of the severed limb before replantation, and in Group B only heporin was given, and Group C and D ascontrol.The results showed that if the hormone and heparin were administred in large dosage, it wasadvantageous to reduce the tissues from reperfusion injury during delayed replantation.
Objective To summarize the influence of microstructure on performance of triply-periodic minimal surface (TPMS) bone scaffolds. Methods The relevant literature on the microstructure of TPMS bone scaffolds both domestically and internationally in recent years was widely reviewed, and the research progress in the imfluence of microstructure on the performance of bone scaffolds was summarized. Results The microstructure characteristics of TPMS bone scaffolds, such as pore shape, porosity, pore size, curvature, specific surface area, and tortuosity, exert a profound influence on bone scaffold performance. By finely adjusting the above parameters, it becomes feasible to substantially optimize the structural mechanical characteristics of the scaffold, thereby effectively preempting the occurrence of stress shielding phenomena. Concurrently, the manipulation of these parameters can also optimize the scaffold’s biological performance, facilitating cell adhesion, proliferation, and growth, while facilitating the ingrowth and permeation of bone tissue. Ultimately, the ideal bone fusion results will obtain. Conclusion The microstructure significantly and substantially influences the performance of TPMS bone scaffolds. By deeply exploring the characteristics of these microstructure effects on the performance of bone scaffolds, the design of bone scaffolds can be further optimized to better match specific implantation regions.
Objective To explore the mechanism of pulmonary hypoplasia in case of congenital diaphragmatic hernia (CDH), and study the ultramicrostructural features of lung tissue of CDH fetal rat models at different developmental stages. Methods Seven SpragueDawley (SD) pregnant rats were randomly divided into CDH group (n=4) and control group (n=3). For the rats in the CDH group, Nitrofen was used to fill in the stomach once at day 9.5 of pregnancy (125 mg of Nitrofen dissolved in 2 ml of olive oil each), and 3, 10, 17 fetal rats were collected at day 16, 18 and 21 of pregnancy respectively. For the rats in the control group, 2 ml of olive oil was used to fill in the stomach, and 10 fetal rats were collected at day 16, 18, and 21 of pregnancy respectively. The lung tissue sections of the fetal rats collected on day 16 were observed under transmission electron microscope (TEM). For the lung tissue of the fetal rats collected on day 18, hematoxylineosin (HE) staining and TEM observation were performed and the incident of CDH was detected. Besides the procedures carried out for the rats collected on day 18, the ratio of fetal lung to body weight was observed for the lung tissue of the fetal rats collected on day 21. Results (1) The ratio of fetal lung to body weight of fetal rats in the CDH group was significantly lower than that of fetal rats in the control group (0.0238 vs. 0.0430, Plt;0.01). The incidences of CDH in the 18thday and 21stday fetal rats in the CDH group were 90.00% and 82.35%respectively, while no CDH was observed in the corresponding fetal rats in the control group, suggesting pulmonary hypoplasia in the CDH group. (2) The ultramicrostructural observation showed that compared with the control group, pulmonary hypoplasia appeared in 16thday fetal lungs in the CDH group, i.e., broad breathing barrier substrate, little contents, predominant euchromatin and rich ribosomes in the alveolar epithelial cells, and no microvilli in the bronchial lumen. The observation on the 18thday and 21stday samples suggested that, with the progressing of pregnancy, the abovementioned features became more obvious. (3) Typical lamellated body was observed in fetal lung type Ⅱ alveolar epithelial cells from the 21stday fetuses in both the CDH group and the control group, suggesting that some late subcellular structures were normal. Conclusion Lung hypoplasia develops in the early period of fetal rats with CDH rather than in the late period, implying that the treatment of pulmonary hypoplasia of diaphragmatic hernia should be performed in the early stage of lung development.
Objective To investigate the effect of collagen peptides from walleye pollock skin on the microstructure of osteoporosis model in ovariectomized rats, and to explore the feasibility of preventing and treating oste- oporosis. Methods Sixty adult Wistar female rats, weighing (250±10) g, were randomly divided into 5 groups (12 rats each group): normal group (group A), osteoporosis model group (group B), osteoporosis model+collagen peptides from walleye pollock skin prevention group (group C), osteoporosis model+low concentration of collagen peptides from walleye pollock skin treatment group (group D), and osteoporosis model+high concentration of collagen peptides from walleye pollock skin treatment group (group E). The rats in groups B, C, D, and E were removed bilateral ovarian to establish osteoporosis model. The rats in group C were treated with stomach perfusion of the collagen peptides from walleye pollock skin (1.0 g/kg) from 4 weeks after operation for 6 weeks; and the rats in groups D and E were treated with stomach perfusion of the collagen peptides from walleye pollock skin (0.5, 1.0 g/kg respectively) at 6 weeks after operation for 6 weeks. The rats in groups A and B were given equal volume of normal saline at the same time after operation. At 24 hours after the last administration, the femoral gray value of rats in groups A and B were measured by X-ray film; HE staining was performed on the proximal tibial bone of the left side in 4 groups; the histopathological changes of the bone were observed and the trabecular number (TN), mean trabecular plate thickness (MTPT), mean trabecular plate spacing (MTPS), trabecular bone volume (TBV), mean bone cortical thickness (MBCT) were measured; immunohistochemical staining was performed to observe the expression levels of caltitonin receptor (CTR) and interleukin 1 (IL-1). Results The femoral gray value of group B was significantly lower than that of group A (t=45.130, P=0.000), which indicated that the ovariectomized rat model was successfully prepared. Histological observation showed that TN, MTPS, TBV, and MBCT in groups A, C, and E were significantly different from those in group B (P<0.05). The histological parameters of bone tissue in group C were significantly different from those in groups D and E (P<0.05). TN, MTPS, TBV, and MBCT in group D were significantly different from those in group A (P<0.05); only MTPS in group E was significantly different from that in group A (P<0.05). MTPS, TBV, and MBCT in group E were significantly different from those in group D (P<0.05). The immunohistochemical staining showed that the levels of CTR and IL-1 in groups A, C, D, and E were lower than those in group B, in groups C and E were lower than in group D, showing significant differences (P<0.05). Conclusion Collagen peptides from walleye pollock skin can improve the bone microstructure of osteoporotic rats, and its mechanism may be related to the inhibition of CTR and IL-1 expression in bone tissue, but it has not been found to prevent osteoporosis.
To serve as carriers of cells and bioactive molecules, three-dimensional scaffolds play a key role in bone defect repair. The chemical component and microstructure of the scaffold can affect the mechanical properties and seed cells. A variety of fabrication techniques have been used in producing scaffolds, some made random porous structure, some created well-designed structure using rapid prototyping methods, and others prepared bio-derived materials as scaffolds. However, scaffolds may vary in their inner structure, mechanical properties and repairing efficiency as well because of different manufacturing methods. In this review, we overview the main achievements concerning the effects of material and microstructure on the mechanical performance, seed cells and defect repair of bone scaffolds.
Mechanical properties and biological evaluation of buffalo horn material were examined in this study. The effects of sampling position of buffalo horn on mechanical properties were investigated with uniaxial tension and micron indentation tests. Meanwhile, the variation of element contents in different parts of buffalo horn was determined with elemental analysis, and the microstructure of the horn was measured with scanning electron microscopy. In addition, biological evaluation of buffalo horn was studied with hemolytic test, erythrocyte morphology, platelet and erythrocyte count, and implantation into mouse. Results showed that the buffalo horn had good mechanical properties and mechanical characteristic values of it gradually increased along with the growth direction of the horn, which may be closely related to its microstructure and element content of C, N, and S in different parts of the buffalo horn. On the other hand, because the buffalo horn does not have toxicity, it therefore does not cause hemolysis of erythrocyte and has a good affinity with it. Buffalo horn has good histocompatibility but meanwhile it may induce the platelet adhesion and aggregation. Even so, it does not continue to rise to induce a large number of platelet to aggregate with resulting blood clotting. Therefore, the buffalo horn material has been proved to possess good blood compatibility according to the preliminary evaluation.
Objective To realize the visualization of three-dimensional microstructure of rabbit sciatic nerve bundles by micro-CT and three-dimensional visualization software Mimics17.0. Methods The sciatic nerve tissues from 6 New Zealand rabbits were divided into 2 groups (n=3), and the sciatic nerve tissues were stained by 1% (group A) and 5% (group B) Lugol solution respectively. After staining for 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 hours, the imaging changes of specimens were observed by light microscope and micro-CT. The clear micro-CT images were exported to the Mimics software to complete the visualization of three-dimensional microstructure of rabbit sciatic nerve according to three-dimensional reconstruction tool. Results The clear three-dimensional microstructure images could be observed in group A at 2.5 hours after staining and in group B at 1.5 hours after staining by light microscope and micro-CT. The sciatic nerve of New Zealand rabbits were divides into 3 bundles and each of them was relatively fixed. There was no obvious crossing or mergers between each bundle. The cross-sectional area of each bundle was (0.425±0.013), (0.038±0.007), and (0.242±0.026) mm2 respectively. The digital model could clearly reflect the microstructure of the sciatic nerve at all cross sections. Conclusion The internal structure of New Zealand rabbits sciatic nerve can be clearly reflected by micro-CT scanning. It provides a reliable method for establishing a nerve microstructure database with large amount specimens.
Diffusion tensor imaging technology can provide information on the white matter of the brain, which can be used to explore changes in brain tissue structure, but it lacks the specific description of the microstructure information of brain tissue. The neurite orientation dispersion and density imaging make up for its shortcomings. But in order to accurately estimate the brain microstructure, a large number of diffusion gradients are needed, and the calculation is complex and time-consuming through maximum likelihood fitting. Therefore, this paper proposes a kind of microstructure parameters estimation method based on the proximal gradient network, which further avoids the classic fitting paradigm. The method can accurately estimate the parameters while reducing the number of diffusion gradients, and achieve the purpose of imaging quality better than the neurite orientation dispersion and density imaging model and accelerated microstructure imaging via convex optimization model.
Objective To investigate effectiveness of the modified edge resection technique for composite labia minora and clitoral hood reduction with preserved microstructures. Methods A retrospective analysis was conducted on 36 female patients, who were diagnosed with composite hypertrophy of the labia minora and clitoral hood and admitted between September 2022 and December 2024. The patients’ ages ranged from 18 to 45 years (mean, 27.4 years). The primary surgical motivations included poor appearance alone (8 cases), functional impairment alone (14 cases), both poor appearance and functional impairment (12 cases), and psychological factors (2 cases). All patients were treated with the modified edge resection technique for composite labiaminora and clitoral hood reduction with preserved microstructures. The surgical technique emphasized precise adjustments to the clitoral-labial junction and optimization of the anterior labial structure to ensure a natural postoperative appearance and functional integrity. Postoperative follow-up assessed improvements in appearance and function of clitoral hood and labia minora, complications, and overall patient satisfaction. Results One patient exhibited suboptimal wound healing, while the remaining patients experienced no complications such as postoperative bleeding, hematoma, wound dehiscence, suture cutting, or labial edema and enlargement. Thirty patients were followed up with a duration of 1-6 months (mean, 2.4 months). In the early postoperative period, 2 patients perceived asymmetry of the bilateral labia minora; 1 underwent labial revision surgery, while the other achieved near-symmetry without intervention. At last follow-up, 25 patients experienced varying degrees of relief from preoperative functional impairments, while the remaining patients showed no improvement; 27 patients reported varying degrees of improvement in appearance, 2 reported no change, and 1 reported a worse appearance compared to preoperatively. Sixteen patients were very satisfied with the surgical results, 8 were satisfied, 5 were moderate satisfied, and 1 was dissatisfied, with a satisfaction rate of 80% (24/30). Conclusion The modified edge resection technique for composite labia minora and clitoral hood reduction with preserved microstructures which preserves and optimizes fine anatomical structures through precise adjustments at the clitoral-labial junction, achieves high patient satisfaction with both aesthetic and functional outcomes while minimizing postoperative complications.
Trabecular microstructure is an important factor in determining bone strength and physiological function. Normal X-ray and computed tomography (CT) cannot accurately reflect the microstructure of trabecular bone. High-resolution peripheral quantitative computed tomography (HR-pQCT) is a new imaging technique in recent years. It can qualitatively and quantitatively measure the three-dimensional microstructure and volume bone mineral density of trabecular bone in vivo. It has high precision and relative low dose of radiation. This new imaging tool is helpful for us to understand the trabecular microstructure more deeply. The finite element analysis of HR-pQCT data can be used to predict the bone strength accurately. We can assess the risk of osteoporosis and fracture with three-dimensional reconstructed images and trabecular microstructure parameters. In this review, we summarize the technical flow, data parameters and clinical application of HR-pQCT in order to provide some reference for the popularization and extensive application of HR-pQCT.