Bio-medical materials and engineering最新文献

Background: Urethral stricture (US) is a common condition that considerably affects patients' quality of life.

Objectives: This study aimed to explore the adoption value of the extracellular vesicle (EV)- small intestinal submucosa (SIS) complex in the repair of USs.

Methods: EVs were extracted from healthy male New Zealand white rabbits, and SIS was prepared using peracetic acid (PAA) oxidation and decellularization. The morphology and particle size of the prepared EV-SIS complex were evaluated using electron microscopy and qNano nanoparticle analyzer, and the labeled proteins of EVs were detected using Western blot method. EV-SIS the complex was implanted in a rabbit model of US, and urodynamic parameters were assessed.

Results: The EV-SIS complex displayed a full morphology, intact membrane structure, and uniform particle size. The protein concentration of EVs in the complex was approximately 0.351 µg/µL, with a yield of approximately 1.86 µg/10⁶ cells. The complex exhibited remarkable repair effects in the rabbit model of US, with bladder capacity, maximal urethral pressure, and minimal urethral pressure all markedly superior to those in the US group (P < 0.05).

Conclusion: The EV-SIS complex demonstrates potential clinical value in the repair of USs, improving urodynamic parameters, and offering a promising therapeutic option for patients with US.

Background: Dissociation is a special type of dislocation that is rarely seen in bipolar hemiarthroplasty.

Objective: To investigate the clinical and biomechanical causes of dissociative dislocation of acetabular cup components in the hips of patients after bipolar hemiarthroplasty (BHA).

Methods: BHA heads were divided into three groups according to their design. Cam-out and pull-out biomechanical tests were conducted to investigate the separation strengths of the BHA heads.

Results: Among the 1684 BHA surgeries performed, the revision surgery rate was 4% (68 hips) and dissociation rate was 0.8% (15 hips). According to the cam-out test result, the highest values in the parameters ultimate force (F_max) ultimate torque (T), vertical displacement at maximum force (δ_m), rotation at maximum force (ϕ_m), maximum principal strain (Ɛ_max), minimum principal strain (Ɛ_min), average normal strain (Ɛ_av), maximum shear strain (γ_max), uniaxial normal strain (Ɛ_un) were detected in Type 2 BHA head. The pull-out values of the implants were sufficient to prevent the distraction force that may occur on the implant due to manual traction applied to the hip dislocations. However, in closed reduction maneuvers, cam-out-shaped deformation forces may cause dissociation in Types 1 and 3, but not in Type 2 BHA heads. According to the pull-out test results, while high values were detected in the parameters Fmax and stiffness (k) in the Type 2 BHA head, δm and maximum force (E) parameters were found to be high in the Type 1 BHA head. In the cam-out test, a strong positive relationship was found between the thickness and width of the polyethylene locking ring and F_max, T, δ_m, ϕ_m, Ɛ_max, γ_max, Ɛ_un.

Conclusion: Better BHA head designs and polyethylene designs may help resolve the rare problem of dissociation, which almost always leads to resurgical procedures.

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: Diabetes is an emerging health issue on a global scale, with increasing prevalence rates reported in many countries. Many mechanisms are proposed for diabetic nephropathy, with oxidative stress being the most significant. The effectiveness of gold nanoparticles (AuNPs) in the attenuation of nephropathy and oxidative stress in diabetic mice was assessed in this study.

Objective: The aim of this study is to synthesize AuNPs and assess their protective effect towards diabetic nephropathy by inhibition of oxidative stress.

Methods: The aqueous extract of Allium sativum was employed to synthesize AuNPs. The prepared AuNPs were characterized using a variety of microscopic and spectroscopic techniques. In-vitro studies were conducted using mice. Streptozotocin (STZ) was employed to induce diabetes in rodents. After 7 days of administration of STZ, anesthesia was given to all animals and blood was collected for the assessment of creatinine and Blood Urea Nitrogen (BUN) levels. Later, kidney tissue was removed at 4 °C and changes in pathology and oxidative stress were assessed.

Results: Nephropathy was confirmed in diabetic mice by the changes in the pathology of kidney tissue along with significant rise in the plasma levels of BUN and creatinine. Additionally, the peroxidation of lipids, formation of Reactive Oxygen Species (ROS), oxidation of glutathione (GSH), concentration of carbonyl protein was also increased in the tissue of kidney of diabetic mice. Oxidative stress in kidney tissue and changes in the pathology of diabetic mice were inhibited significantly (p < 0.05) with the treatment of AuNPs.

Conclusion: This study revealed the protective effects of AuNPs over diabetic nephropathy by inhibiting the pathway of oxidative stress. Since, the prepared AuNPs showed improvement over complications of diabetes, they may be believed as a potential gratuitous treatment next to other drugs for reducing blood glucose.

Background: Nanomaterials have applications in traditional Chinese medicine in the fields of medical equipment manufacturing, targeted transportation, and drug synergistic therapy.

Objective: The research aims to discuss the performance and performance of zinc-iron-based nanomaterials in medical drug delivery and synergistic drug therapy.

Methods: Using Prussian materials as precursors, magnetic zinc-iron nanomaterials were prepared by ZnCl₂ and K₃[Fe (CN)₆]. Moreover, the morphology and composition of the material were analyzed.

Results: X-ray analysis was conducted on the prepared Zn₃[Fe (CN)₆]₂·xH₂O nanomaterials, and their purity met the design requirements. At the same time, drug loading analysis was conducted on Zn₃[Fe(CN)₆]₂·xH₂O, and the release of capsaicin reached 86.3% under a certain phosphate buffer solution. Meanwhile, Zn₃[Fe (CN)₆]₂·xH2O loaded tetracycline could release up to 90% in phosphate buffer solution. Antibacterial tests were conducted on self-made Zn₃[Fe(CN)₆]₂·xH₂O samples and ZnFe₂O₄/ZnO. The Zn₃[Fe(CN)₆]₂·xH₂O samples showed a more significant inhibitory effect on cancer cells after loading with capsaicin.

Conclusion: The zinc-iron-based nanomaterials prepared by the research have excellent performance in drug loading and safety, indicating their significant potential for development in the medical field.

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: 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: 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.