3D Printed TCP-Based Scaffold Incorporating VEGF-Loaded PLGA Microspheres for Craniofacial Tissue Engineering

Objective Vascularization is a critical process during bone regeneration/repair and the lack of tissue vascularization is recognized as a major challenge in applying bone tissue engineeringmethods for cranial and maxillofacial surgeries. The aim of our study is to fabricate a vascular endothelial growth factor (VEGF)-loaded gelatin/alginate/β-TCP composite scaffold by 3D printing method using a computer-assisted design (CAD) model. Methods The paste, composed of (VEGF-loaded PLGA)-containing gelatin/alginate/β-TCP in water, was loaded into standard Nordson cartridges and promptly employed for printing the scaffolds. Rheological characterization of various gelatin/alginate/β-TCP formulations led to an optimized paste as a printable bioink at room temperature. Results The in vitro release kinetics of the loaded VEGF revealed that the designed scaffolds fulfill the bioavailability of VEGF required for vascularization in the early stages of tissue regeneration. The results were confirmed by two times increment of proliferation of human umbilical vein endothelial cells (HUVECs) seeded on the scaffolds after 10 days. The compressive modulus of the scaffolds, 98 ± 11 MPa, was found to be in the range of cancellous bone suggesting their potential application for craniofacial tissue engineering. Osteoblast culture on the scaffolds showed that the construct supports cell viability, adhesion and proliferation. It was found that the ALP activity increased over 50% using VEGF-loaded scaffolds after 2 weeks of culture. Significance The 3D printed gelatin/alginate/β-TCP scaffold with slow releasing of VEGF can be considered as a potential candidate for regeneration of craniofacial defects

The generalized second law in chameleon cosmology

In this paper, we investigate the validity of the generalized second law (GSL) of thermodynamics in flat FRW chameleon cosmology where the boundary of the universe is assumed to be enclosed by the dynamical apparent horizon. It has been shown that, in a bouncing scenario for the universe with phantom crossing, the total entropy decreases with time in the contracting epoch, whereas, the dynamics of the internal and horizon entropies depends on the behavior of both equation of state and hubble parameters.Comment: 10 pages, 6 figures; To be published in Can. J. Phy

Development of a DNA-Liposome Complex for Gene Delivery Applications

The association structures formed by cationic liposomes and DNA(Deoxyribonucleic acid)-liposome have been effectively utilized as gene carriers in transfection assays. In this research study, cationic liposomes were prepared using a modified lipid film hydration method consisting of a lyophilization step for gene delivery applications. The obtained results demonstrated that the mean particle size had no significant change while the polydispersity (PDI) increased after lyophilization. The mean particle size slightly reduced after lyophilization (520 ± 12 nm to 464 ± 25 nm) while the PDI increased after lyophilization (0.094 ± 0.017 to 0.220 ± 0.004). In addition. The mean particle size of vesicles increases when DNA is incorporated to the liposomes (673 ± 27 nm). According to the Scanning Electron Microscopy(SEM) and transmission electron microscopy (TEM) images, the spherical shape of liposomes confirmed their successful preservation and reconstitution from the powder. It was found that liposomal formulation has enhanced transfection considerably compared to the naked DNA as negative control. Finally, liposomal formulation in this research had a better function than Lipofectamine® 2000 as a commercialized product because the cellular activity (cellular protein) was higher in the prepared lipoplex than Lipofectamine® 2000

Liver transplant recipients quality of life instrument: Development and psychometric testing

Background: Liver transplantation is a life-saving intervention for many patients with end-stage liver disease. In the past, evaluation of successful liver transplantation was based on patients' survival rate. However, in recent years this evaluation has been based on patients' quality of life. Various instruments have been developed to evaluate patients' quality of life. Nonetheless, scholars still believe that it is crucial to develop a standardized and disease specific instrument for evaluating the quality of life in liver transplant recipients. Objectives: The aim of this paper was to describe the development and psychometric testing process of a quality of life instrument specific to liver transplant recipients. Materials and Methods: Initial items of this instrument were extracted from a conventional content analysis study, and then were completed with findings of related international literature. The face validity was assessed by interviewing with four liver transplant recipients, and the content validity was evaluated by eleven experts in the field of transplantation. The construct validity was achieved by involving 250 liver transplant recipients through exploratory factor analysis method, and reliability was calculated by Cronbach's alpha. Results: Three main factors with 40 items were extracted from the exploratory factor analysis: Health Satisfaction, Concerns, and Complications. Reliability of the instrument was confirmed (alpha = 0.922). Conclusions: Given the special considerations regarding liver transplant recipients, this questionnaire is more accurate in evaluating the success of liver transplantation. © 2013, Kowsar Corp.; Licensee Kowsar Ltd

Brachial vein transposition with consecutive skin incisions in a hemodialysis patient with absence of adequate superficial veins: A case report

The creation of an arteriovenous fistula instead of a synthetic vascular graft is a smart decision in hemodialysis patients who do not have a suitable superficial vein. Basilic vein transposition (BVT) is a viable option in most cases, except in patients who do not have a proper basilic vein. In patients with inadequate superficial veins, another source of the autogenous vein is the brachial vein, a deep vein of the upper arm. Most surgeons choose a full medial arm incision to perform brachial vein exploration. We describe a patient in whom BVT was not possible and so brachial vein transposition using skip incisions was performed, with good results. Copyright © 2020 The Korean Society for Vascular Surgery This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited

Environment and harvest time affects the combustion qualities of Miscanthus genotypes

Miscanthus spp. are high-yielding perennial C4 grasses, native to Asia, that are being investigated in Europe as potential biofuels. Production of economically viable solid biofuel must combine high biomass yields with good combustion qualities. Good biomass combustion quality depends on minimizing moisture, ash, K, chloride, N, and S. To this end, field trials at five sites in Europe from Sweden to Portugal were planted with 15 different genotypes including M. x giganteus, M. sacchariflorus, M. sinensis, and newly bred M. sinensis hybrids. Yield and combustion quality at an autumn and a late winter/ early spring harvest were determined in the third year after planting when the stands had reached maturity. As expected, delaying the harvest by three to four months improved the combustion quality of all genotypes by reducing ash (from 40 to 25 g kg-1 dry matter), K (from 9 to 4 g kg-1 dry matter), chloride (from 4 to 1 g kg-1 dry matter), N (from 5 to 4 g kg-1 dry matter), and moisture (from 564 to 291 g kg-1 fresh matter). However, the delayed harvest also decreased mean biomass yields from 17 to 14 t ha-1. There is a strong interaction among yield, quality, and site growing conditions. Results show that in northern regions of Europe, M. sinensis hybrids can be recommended for high yields (yielding up to 25 t ha-1), but M. sinensis (nonhybrid) genotypes have higher combustion qualities. In mid- and south Europe, M. giganteus (yielding up to 38 t ha-1) or specific high-yielding M. sinensis hybrids (yielding up to 41 t ha-1) are more suitable for biofuel production

Anterior cruciate ligament reconstruction with hamstring tendons has no deleterious effect on hip extension strength

Background: Hamstring tendons are secondary hip extensors. Their harvest for graft in anterior cruciate ligament (ACL) reconstruction may create deleterious effect on hip extension strength. This is of particular importance in sports that need powerful hip extension force like climbing and sprinting. Due to scarcity of a comprehensive study in this area, we designed this prospective study to evaluate hip extension strength following ACL reconstruction using different types of grafts. Methods: Fifty eight patients were enrolled in this prospective non-randomized case control study to compare isokinetic hip extension strength following ACL reconstruction with different graft types. Twenty patients in group A (both Semitendinosus and Gracilis tendons autograft (ST-G)), 14 patients in group B (Tibialis Posterior tendon allograft (Allograft)), 12 patients in group C (bone-patellar tendon-bone autograft (BPTB)) and 12 patients in group D (only semitendinosus autograft (ST)) were studied. Hip extension strength was tested post-operatively at three- and six-month periods using a Biodex isokinetic testing machine at a speed of 30 degree per second in operated (cases) and non-operated (controls) limbs. Results: There was a significant increase in hip extension force between three and six month intervals in all four groups and in both operated (case) and non-operated (control) limbs (P<0.05, 95 CI). However, there was more increase in case limbs in comparison to control limbs. There was no significant difference in hip extension strength among all four groups (both in case and control limbs) in the third- and the sixth-month post-operative tests. Conclusion: Graft type had no effect on hip extension strength following ACL reconstruction, and the harvest of one or both hamstrings had no deleterious effect on hip extension force. COPYRIGHT 2019 © BY THE ARCHIVES OF BONE AND JOINT SURGERY

Temperature and pH-responsive nano-hydrogel drug delivery system based on lysine-modified poly (vinylcaprolactam).

BACKGROUND: Smart materials capable of responding to external stimuli are noteworthy candidates in designing drug delivery systems. In many of the recent research, temperature and pH have been recognized as the main stimulating factors in designing systems for anti-cancer drugs delivery systems. PURPOSE: In this study, thermo and pH-responsive character of a nano-carrier drug delivery platform based on lysine modified poly (vinylcaprolactam) hydrogel conjugated with doxorubicin was assessed. METHODS: Poly (vinylcaprolactam) cross-linked with poly (ethyleneglycol) diacrylate was prepared via RAFT polymerization, and the prepared structure was linked with lysine through ring-opening. The anti-cancer drug doxorubicin, was linked to lysine moiety of the prepared structure via Schiff-base reaction. The prepared platform was characterized by 1HNMR and FT-IR, while molecular weight characterization was performed by size exclusion chromatography. The temperature-responsive activity was evaluated using differential scanning calorimetry and dynamic light scattering. In vitro release pattern in simulated physiologic pH at 37°C was compared with acidic pH attributed to tumor site and elevated temperature. The anticancer efficiency of the drug-conjugated structure was evaluated in breast cancer cell line MCF-7 in 24 and 48 h, and cell uptake assay was performed on the same cell line. CONCLUSION: According to the results, well-structure defined smart pH and temperature responsive nano-hydrogel was prepared. The enhanced release rates are observed at acidic pH and elevated temperature. We have concluded that the doxorubicin-conjugated nanoparticle results in higher cellular uptakes and more cytotoxicity