Bio-medical materials and engineering最新文献

Background: Hypertensive disorders during pregnancy pose significant risks to both maternal and fetal health, necessitating safe and effective therapeutic interventions.

Objective: This study aimed to investigate the potential of an extract derived from Falcaria vulgaris (FV), loaded with exosomes to form the Exo/FV complex, as a novel therapeutic agent for the management of hypertension in pregnant mice: antioxidants, antimicrobials, and phenolic compounds present in FV lower blood pressure.

Methods: The isolation of exosomes was done by ultracentrifugation methods and the FV was loaded into the exosomes by electroporation method.

Results: The Exo/FV was found to be spherical with diameter ranges from 20 to 30 nm and they were tested for biocompatibility in NHI 3T3 cell lines and found to be effective. This research investigated in vivo hypertension in mice induced by L-NAME and treated with FV and Exo/FV and found that AChE and MAO determine mice's redox state tends to reduce blood pressure. Increased non-protein thiol (NP-SH) and decreased lipid peroxidation were also found, and PDE-5, ACE, Arginase, and MDA activity has also been tested.

Conclusion: This analysis showed that Exo/FV effectively treated hypertension during pregnancy.

Background: Acupuncture and moxibustion are effective in alleviating symptoms, but the large number of acupoints can make accurate needle placement and training difficult.

Objective: To address these challenges, this study aims to develop an augmented reality (AR) acupuncture navigation system designed to improve the accuracy and intuitiveness of acupoint localization.

Methods: The proposed system employs a six-point registration and positioning technique, enabling the AR navigation model to adapt to the specific characteristics of each patient.

Results: In testing, discrepancies between virtual and actual acupuncture points ranged from 0.6 mm to 3.9 mm, which is within the acceptable tolerance range for acupuncture.

Conclusion: This AR-based system shows promise in enhancing the precision of acupuncture point localization, potentially leading to improved treatment outcomes.

Background: Myocardial infarction leads to myocardial necrosis, and cardiomyocytes are non-renewable. Fatty acid-containing cardiomyocyte maturation medium promotes maturation of stem cell-derived cardiomyocytes.

Objective: To study the effect palmitic acid on maturation of cardiomyocytes derived from human embryonic stem cells (hESCs) to optimize differentiation for potential treatment of myocardial infarction by hESCs.

Methods: hESCs were differentiated into cardiomyocytes using standard chemically defined medium 3 (CDM3). Up to day 20 of differentiation, 200 Mm palmitic acid were added, and then the culture was continued for another 8 days to mimic the environment in which human cardiomyocytes mainly use fatty acids as the main energy source. Light microscopy, transmission electron microscopy, immunofluorescence, reverse transcription-polymerase chain reaction, and cellular ATP assays, were carried out to analyze the expression of relevant cardiomyocyte-related genes, cell morphology, metabolism levels, and other indicators cardiomyocyte maturity.

Results: Cardiomyocytes derived from hESCs under exogenous palmitic acid had an elongated pike shape and a more regular arrangement. Sarcomere stripes were clear, and the cells color was clearly visible. The cell perimeter and elongation rate were also increased. Myogenic fibers were abundant, myofibrillar z-lines were regularly, the numbers of mitochondria and mitochondrial cristae were higher, more myofilaments were observed, and the structure of round-like discs was occasionally seen. Expression of mature cardiomyocyte-associated genes TNNT2, MYL2 and MYH6, and cardiomyocyte-associated genes KCNJ4, RYR2,and PPARα, was upregulated (p < 0.05). Expression of MYH7, MYL7, KCND2, KCND3, GJA1 and TNNI1 genes was unaffected (p > 0.05). Expression of mature cardiomyocyte-associated sarcomere protein MYL2 was significantly increased (p < 0.05), MYH7 protein expression was unaffected (p > 0.05). hESC-derived cardiomyocytes exposed to exogenous palmitic acid produced more ATP per unit time (p < 0.05).

Conclusion: Exogenous palmitic acid induced more mature hESC-CMs in terms of the cellular architecture, expression of cardiomyocyte maturation genes adnprotein, and metabolism.

Background: Restoration of the abdominal wall defects due to herniation or other complications represents a challenging task of the reconstructive surgery. Synthetic grafts or crosslinked animal-derived grafts, are utilized, followed by significant adverse reactions.

Objective: This study aimed to evaluate primarily the production of a decellularized abdominal wall scaffold and secondly its biocompatibility upon transplantation in an animal model.

Methods: Full-thickness abdominal wall samples were harvested from Wistar Rats and then decellularized utilizing a three-cycle process. To evaluate the decellularization efficacy, histological, biochemical and biomechanical analyses were performed. The biocompatibility assessment involved the implantation of the produced scaffolds to Sprague Dawley rats. The grafts remained for a total period of 4 weeks, followed by immunohistochemistry for the detection of CD11b+, CD4+ and CD8+ cells.

Results: Histological, biochemical and biomechanical results, indicated the production of compatible acellular full-thickness abdominal wall samples. After 4 weeks of implantation, a minor presence of immunity cells was observed.

Conclusion: The data of this study indicated the successful production of a full-thickness abdominal wall scaffold. Biologically derived full-thickness abdominal wall scaffolds may have greater potential in restoration of the abdominal wall defects, bringing them one step closer to their clinical utility.

Background: Polylactic acid (PLA) has been extensively used in tissue engineering. However, poor mechanical properties and low cell affinity have limited its pertinence in load bearing bone tissue regeneration (BTR) devices.

Objective: Augmenting PLA with β-Tricalcium Phosphate (β-TCP), a calcium phosphate-based ceramic, could potentially improve its mechanical properties and enhance its osteogenic potential.

Methods: Gels of PLA and β-TCP were prepared of different % w/w ratios through polymer dissolution in acetone, after which polymer-ceramic membranes were synthesized using the gel casting workflow and subjected to characterization.

Results: Gel-cast polymer-ceramic constructs were associated with significantly higher osteogenic capacity and calcium deposition in differentiated osteoblasts compared to pure polymer counterparts. Immunocytochemistry revealed cell spreading over the gel-cast membrane surfaces, characterized by trapezoidal morphology, distinct rounded nuclei, and well-aligned actin filaments. However, groups with higher ceramic loading expressed significantly higher levels of osteogenic markers relative to pure PLA membranes. Rule of mixtures and finite element models indicated an increase in theoretical mechanical strength with an increase in β-TCP concentration.

Conclusion: This study potentiates the use of PLA/β-TCP composites in load bearing BTR applications and the ability to be used as customized patient-specific shape memory membranes in guided bone regeneration.

Background: The preservation period afforded by cold storage of cells is short. However, the use of rare gases for cold storage as a means of extending the period of preservation would be highly beneficial.

Objective: To examine the effect of temperature on the protective effect of cold storage of cells using pressurized dissolution of xenon gas, with particular focus on the inhibition of substance transport by viscosity.

Methods: Human dermal fibroblast monolayers incubated in a culture dish for 48 h were used as a test sample, with culture medium used as a preservation solution. Samples were placed into a pressure-resistant vessel, which was pressurized with xenon gas at 0 or 0.5 MPa, and cells were stored at 0 to 5 °C for 18 h. Cell activity was evaluated by tetrazolium salt assay. The viscosity of the medium under pressurization at each storage temperature was estimated.

Results: The maximum protective effect against cell damage of cold storage with pressurized dissolution of xenon gas was observed at 4 °C. An increase in estimated viscosity by pressurization was correlated with increased cell activity at 4 °C.

Conclusion: Analysis of the temperature dependence of the protective effect against cell damage of cold storage with pressurized dissolution of xenon gas revealed that the most effective temperature is 4 °C. The data also suggest that increased viscosity due to pressurization plays a role in the protective effect.

Background: Vascular endothelial injury, a key factor in diabetic foot ulcers (DFUs) pathogenesis, is linked to the impaired proliferation and migration of vascular endothelial cells, modulated by hypoxia-inducible factor, growth factors, and inflammatory elements.

Objective: The present study assesses the role of SIKVAV (Ser-Ile-Lys-Val-Ala-Val), a peptide shown to enhance cell proliferation and migration, on mouse aortic endothelial cell (MAEC) and the corresponding molecular mechanisms.

Methods: MAEC were treated with SIKVAV at 0, 100, 200, 400, and 600 μg/mL for 0, 24, 48, and 72 h. Cell viability was tested using the CCK-8 assay. Proliferating cell nuclear antigen (PCNA), extracellular signal-regulated kinase 1/2 (ERK1/2), and protein kinase B (Akt) levels were measured by qRT-PCR and western blot.

Results: SIKVAV augmented PCNA mRNA expression and stimulated vascular endothelial cell proliferation in a concentration and time-dependent fashion. Furthermore, it amplified the expression of p-ERK1/2 and p-Akt, pivotal components of the mitogen-activated protein kinase (MAPK)/ERK1/2 and phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathways. The inhibition of these pathways suppressed PCNA mRNA expression, cell proliferation rate, and decreased p-ERK1/2 and p-Akt levels, highlighting SIKVAV's role in promoting vascular endothelial cell proliferation via these pathways.

Conclusion: The results of this study confirmed that SIKVAV grafted onto scaffolds can accelerate the proliferation of vascular endothelial cells for the therapy of skin wounds, and provide a theoretical basis for its application in ischemic disease as synthesized biomaterials scaffolds of tissue engineering.

Background: Osteoarthritis is a prevalent joint disease affecting both humans and animals. It is characterized by articular cartilage degeneration and joint surface eburnation. Currently, no effective pharmacological treatment is available to restore the original function and structure of defective cartilage.

Objective: This study explores the potential of stem cell-based therapy in treating joint diseases involving cartilage degeneration, offering a promising avenue for future research and treatment. The primary aim was to compare the characteristics and, more importantly, the chondrogenic differentiation potential of human and rat adipose-derived mesenchymal stem cells (AD-MSCs).

Methods: Rat adipose tissue was collected from Sprague Dawley rats, while human adipose tissue was obtained in the form of lipoaspirate. The mesenchymal stem cells (MSCs) were then harvested using collagenase enzyme and subcultured. We meticulously evaluated and compared the cell morphology, percentage of cell viability, population doubling time, metabolic proliferation, and chondrogenic differentiation potential of MSCs harvested from both sources. Chondrogenic differentiation was induced at passage 3 using the 3D pellet culture method and assessed through histological and molecular analysis.

Results: The findings revealed that human and rat AD-MSCs were phenotypically identical, and an insignificant difference was found in cell morphology, percentage of cell viability, metabolic proliferation, and population doubling time. However, the chondrogenic differentiation potential of human AD-MSCs was evaluated as significantly higher than that of rat AD-MSCs.

Conclusion: The current study suggests that research regarding chondrogenic differentiation of rat AD-MSCs can be effectively translated to humans. This discovery is a significant contribution to the field of regenerative medicine and has the potential to advance our understanding of stem cell-based therapy for joint diseases.

Background: Accurate measurement of bone alignment of the knee during walking provides ideal clinical information for diagnosis and treatment of knee joint disorders. To bring this ideal closer to clinical reality, we developed an image matching technique to measure the three-dimensional (3D) position of bones using anteroposterior radiography during the stance phase of treadmill walking.

Objective: To develop and validate an image matching method for evaluation of 3D knee alignment using anteroposterior radiography of artificial femoral and tibial bones.

Methods: The 3D position of each bone was recovered by minimizing the difference between the projected outline and the contour of the bone in the anteroposterior radiograph. The true value of the position was measured using a 3D coordinate measuring machine.

Results: The mean values ± standard deviation and root mean squares (RMS) of translation errors were within -1.6 ± 2.1 mm and 2.6 mm, respectively, for femur, and 2.1 ± 1.9 mm and 2.8 mm for tibia. The mean values ± standard deviation and RMS of errors in rotation were within 0.3 ± 0.7° and 0.7°, respectively, for femur, and -0.3 ± 0.9° and 0.9°, respectively, for tibia.

Conclusion: Our method is suitable for evaluating 3D knee alignment on anteroposterior radiography.