Cell-printing methods have been used widely in tissue regeneration because they enable fabricating biomimetic 3D structures laden with various cells. To achieve a cell-matrix block, various natural hydrogels that are nontoxic, biocompatible, and printable have been combined to obtain "bioinks." Unfortunately, most bioinks, including those with alginates, show low cell-activating properties. Here, a strategy for obtaining highly bioactive ink, which consisted of collagen/extracellular matrix (ECM) and alginate, for printing 3D porous cell blocks is developed. An in vitro assessment of the 3D porous structures laden with preosteoblasts and human adipose stem cells (hASCs) demonstrates that the cells in the bioinks are viable. Osteogenic activities with the designed bioinks show much higher levels than with the "conventional" alginate-based bioink. Furthermore, the hepatogenic differentiation ability of hASCs with the bioink is evaluated using the liver-specific genes, albumin, and TDO2, under hepatogenic differentiation conditions. The genes are activated within the 3D cell block fabricated using the new bioink. These results demonstrate that the 3D cell-laden structure fabricated using collagen/ECM-based bioinks can provide a novel platform for various tissue engineering applications.
Electrohydrodynamic (EHD) direct writing has been used in diverse microelectromechanical systems and various supplemental methods for biotechnology and electronics. In this work, we expanded the use of EHD-induced direct writing to fabricate 3D biomedical scaffolds designed as porous structures for bone tissue engineering. To prepare the scaffolds, we modified a grounded target used in conventional EHD direct printing using a poly(ethylene oxide) solution bath, elastically cushioning the plotted struts to prevent crumbling. The fabricated scaffolds were assessed for not only physical properties including surface roughness and water uptake ability but also biological capabilities by culturing osteoblast-like cells (MG63) for the EHD-plotted polycaprolactone (PCL) scaffold. The EHD-scaffolds showed significantly roughened surface and enhanced water-absorption ability (400% increase) compared with the pure rapid-prototyped PCL. The results of cell viability, alkaline phosphatase activity, and mineralization analyses showed significantly enhanced biological properties of the scaffold (20 times the cell viability and 6 times the mineralization) compared with the scaffolds fabricated using RP technology. Because of the results, the modified EHD direct-writing process can be a promising method for fabricating 3D biomedical scaffolds in tissue engineering.
We report a cell-dispensing technique, using a core-shell nozzle and an absorbent dispensing stage to form cell-embedded struts. In the shell of the nozzle, a cross-linking agent flowed continuously onto the surface of the dispensed bioink in the core nozzle, so that the bioink struts were rapidly gelled, and any remnant cross-linking solution during the process was rapidly absorbed into the working stage, resulting in high cell-viability in the bioink strut and stable formation of a threedimensional mesh structure. The cell-printing conditions were optimized by manipulating the process conditions to obtain high mechanical stability and high cell viability. The cell density was 1 × 10 7 mL −1 , which was achieved using a 3-wt% solution of alginate in phosphate-buffered saline, a mass fraction of 1.2 wt% of CaCl 2 flowing in the shell nozzle with a fixed flow rate of 0.08 mL min −1 , and a translation velocity of the printing nozzle of 10 mm s −1 . To demonstrate the applicability of the technique, preosteoblasts and human adipose stem cells (hASCs) were used to obtain cell-laden structures with multi-layer porous mesh structures. The fabricated cell-laden mesh structures exhibited reasonable initial cell viabilities for preosteoblasts (93%) and hASCs (92%), and hepatogenic differentiation of hASC was successfully achieved.Tissue engineering has been widely applied to the regeneration of damaged tissues and organs using a combination of cells, an engineered extracellular matrix (or scaffold), and appropriate bioactive growth and differentiation factors 1,2,3 . The scaffold has been shown to be an important factor in cell attachment, growth, and differentiation; however, the mechanisms for the effects of the chemical and biological compositions and the physical structures that are required to encourage proper tissue regeneration are not completely understood 4 .Biomedical scaffolds for tissue engineering should possess various chemical and physical properties, including biocompatibility, with minimal cytotoxic effects to allow high cell attachment and proliferation; should be biodegradable; should have a highly porous structure (appropriate pore size, tortuosity, pore-interconnectivity) to enable easy vascularization and efficient transportation of nutrients and metabolic waste; and should have appropriate mechanical properties to endure the compressive and shear stresses from the micro-environmental conditions 5,6,7 .
In this cohort of healthy men hemodilution from increased plasma volume may be responsible for the observed decreased tumor marker concentration in men with a higher body mass index. In addition, an increase in body mass index may predict a lower tumor marker concentration in an individual.
Introduction: In Korea, increasing attention has recently been given to the use of phytotherapeutic agents to alleviate the symptoms of BPH. Serenoa repens has been shown to have an equivalent efficacy to Finasteride or Tamsulosin in the treatment of BPH in previous studies. The present study was designed to compare the efficacy and safety of Serenoa repens plus tamsulosin with tamsulosin only over 12 months in men with LUTS secondary to BPH. Materials and Methods: One hundred forty men with symptomatic BPH (IPSS ≥10) were recruited in our hospital for a 12-month, open-label, randomized trial. Patients were randomly assigned to either tamsulosin 0.2 mg/day plus Serenoa repens 320 mg/day (n = 60) or tamsulosin 0.2 mg/day only (n = 60). Prostate volume and PSA were measured at baseline and at end-point, whereas total IPSS, and its storage and voiding subscores, LUTS-related QoL, Qmax, and PVR were evaluated at baseline and later every 6 months. Results: Total 103 patients were finally available: 50 in the TAM + SR group and 53 in the TAM group. At 12 months, total IPSS decreased by 5.8 with TAM + SR and 5.5 with TAM (p = 0.693); the storage symptoms improved significantly more with TAM + SR (-1.7 vs. -0.8 with TAM, p = 0.024). This benefit with regard to storage symptom in the TAM + SR group lasts at 12 months (-1.9 vs. -0.9, p = 0.024). The changes of voiding subscore, LUTS-related QoL, Qmax, PVR, PSA, and prostate volume showed no significant differences between the TAM + SR and TAM groups. During the treatment period, 8 patients (16.9%) with TAM and 10 (20%) with TAM + SR had drug-related adverse reactions, which included ejaculatory disorders, postural hypotension, dizziness, headache, gastro-intestinal disorders, rhinitis, fatigue and asthenia. Conclusions: The combination treatment of Serenoa repens and tamsulosin was shown to be more effective than tamsulosin monotherapy in reducing storage symptoms in BPH patients after 6 months and up to 12 months of treatment.
Velocardiofacial syndrome (VCFS) is associated with velopharyngeal insufficiency, which occurs in approximately 75% of VCFS patients. Surgical management of velopharyngeal insufficiency in VCFS patients is difficult with a high revision rate due to the anatomic and physiological abnormalities of the velopharynx. The aims of this study were to evaluate the thickness and symmetry of the levator veli palatini (LVP) muscle using magnetic resonance imaging (MRI), and to compare the findings in VCFS patients to those in patients with nonsyndromic submucous cleft palate. We conducted a prospective analysis of 17 VCFS patients (nine boys, eight girls; age range, 4-9 years) and nine patients with submucous cleft palate without VCFS (eight boys, one girl; age range, 4-13 years) who had undergone MRI between March 2009 and August 2013. The thickness of the LVP muscle was measured at six locations in both groups. The symmetry was determined by comparing the values between the average of the left three points and the right three points. The mean LVP muscle thickness was significantly thinner in VCFS patients (2.14 ± 0.73 mm) than in patients without VCFS (3.70 ± 1.08 mm) (p < 0.001). In addition, the difference between the left and right sides of muscle thickness in the VCFS group was larger than that in the nonsyndromic submucous cleft palate group (0.25 and 0.09 mm, respectively). The thinness and asymmetry of the LVP muscle should be considered when determining the surgical management of velopharyngeal insufficiency in VCFS patients.
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