L-asparaginase has been used in the treatment of patients with acute lymphoblastic leukemia (ALL) for more than 30 years. Rapid clearance of the enzyme from blood stream and its ...L-glutaminase-dependent neurotoxicity has led to searching for new L-asparaginases with more desirable properties. In the present study, L-asparaginase coding gene of
Halomonas elongata
was isolated, expressed in
Escherichia coli
, purified, and characterized. The purified protein was found to have a molecular mass of 39.5 kDa and 1000-folds more activity towards L-asparagine than L-glutamine. Enzyme-specific activity towards L-asparagine was determined to be 1510 U/mg, which is among the highest reported values for microbial L-asparaginases.
K
m
, V
max
, and
k
cat
values were 5.6 mM, 2.2 μmol/min, and 1.96 × 10
3
1/S, respectively. Optimum temperature was found to be 37 °C while the enzyme showed maximum activity at a wide pH range (from 6 to 9). Enzyme half-life in the presence of human serum at 37 °C was 90 min which is three times higher when compared with reported values for
E. coli
L-asparaginase. Enzyme showed cytotoxic effects against Jurkat and U937 cell lines with an IC
50
of 2 and 1 U/ml, respectively. Also, no toxic effects on human erythrocytes and Chinese hamster ovary cell lines were detected, and just minor inhibitory effects on human umbilical vein endothelial cells were observed. This is the first report describing the therapeutic potentials of a recombinant L-asparaginase isolated from a halophilic bacterium as an anticancer agent.
One of the most substantial complications in orthopedic surgeries is implant associated infection. While the implant interface can be a permissive surface for bacterial colonization, an appropriate ...coating on the implant can effectively hinder biofilm formation. To this aim, henna and thyme extract loaded into a chitosan (CS)/polyethylene oxide (PEO) based nanofibrous hydrogel. CS/PEO/henna and CS/PEO/thymus extract nanofibers were fabricated via two-nozzle electrospinning. The proper weight ratio of CS/PEO/herbal extract was optimized. The appropriate ratio of CS/PEO and the most suitable extract concentrations was obtained to be 7/3 (v/v) and 1 % (v/v), respectively. Contact angle measurements showed an appropriate degree of hydrophilicity in all groups including herbal loaded electrospun nanosheets. Tensile strength measurements showed that inclusion of henna and thymus made minor changes in tensile strength and strain of herbal loaded nanofiber, compared to control CS/PEO fibers. Then antibacterial tests were performed and the fibers either by themselves or when used as coating on orthopedic screws exhibited a good inhibition zone against both gram negative and gram positive bacteria. The coatings showed no adverse effect on the red blood cells in leading to hemolysis. Cytocompatibility assay indicated that the prepared nanofibrous hydrogel coating was absolutely biocompatible as tested with fibroblast cells. The results of this study indicated that our henna and thyme extracts loaded CS/PEO coatings can be used in various medical fields such as wound dressing and implantation coating to prevent bacterial adhesion, growth and generally, infection.
Using poly(lactic acid) (PLA) as biodegradable and biocompatible material is demanded for vascular scaffolds especially a susceptible substitute of permanent metal stents in treatment of coronary ...heart disease. In this work, PLA nanofibers containing aspirin (Asp) loaded into zeolitic imidazolate framework nanoparticles (ZIF-8@Asp NPs) were prepared for vascular tissue application. In this line, ZIF-8@Asp NPs were synthesized, and their characterization revealed their average NP size and the drug loading efficiency of approximately 180 nm and 76 %. Afterward, ZIF-8@Asp NPs were loaded into PLA nanofibers and the obtained results showed a uniform morphology with an average nanofibers diameter of around 544 nm, Young’s modulus of 1.7 MPa, and the ultimate drug release of 19 % after six days. Besides degradation studies of the sample, the addition of ZIF-8@Asp NPs to the PLA nanofibers displayed no adverse effect on the shape recovery properties. Finally, the hemolysis and platelet adhesion confirmed that the surface of the ZIF-8@Asp-loaded PLA nanofibrous samples exhibited appropriate hemocompatibility.
Coating polymeric nanofibers with anti-coagulant agents is one of the most important methods to enhance the performance of these materials against blood interactions. In this work, poly(ethylene ...terephthalate) (PET)/graphene oxide (GO) nanofibers coated with heparin (Hep) were fabricated and their physicochemical properties alongside hemocompatibility were investigated. To study the effect of GO on PET nanofibers, the electrical conductivity of 4.08x10
−8
S cm
−1
and elastic modulus of approximately 47 MPa for sample containing 3 wt.% of GO (PET/GO 3) were observed. After NH
3
plasma, Hep was coated on the optimal PET/GO 3 nanofibrous sample and Fourier transform infrared spectroscopy as well as water contact angle results exhibited the appropriate Hep coating by dedicating characteristic peak of 1187 cm
−1
and 25 °, respectively. In addition, the scanning electron microscopic images of PET/GO 3 nanofibers showed Hep coating has no significant influence on the size of nanofibrous diameter. Prothrombin time and partial thromboplastin time were increased up to 106 s and 350 s; additionally, the number of platelets and hemolytic index were decreased in PET/GO 3 nanofibers in presence of Hep. Eventually, cultivation of mesenchymal stem cells revealed that the sample coated with Hep dedicated the highest cell proliferation with the most living cells. The overall outcomes conducted us the Hep-coated PET/GO 3 nanofibrous sample was a promising candidate for vascular tissue engineering.
In the field of vascular tissue engineering, the incorporation of anticoagulant drugs into polymeric nanofibers is a key strategy to enhance performance and prevent thrombosis. This study focuses on ...preparation of electro-spun poly(ethylene terephthalate) (PET)/carboxylated multi-walled carbon nanotubes (MWCNTs) nanofibers containing aspirin (Asp) as potential vascular substitutes. Various tests, including SEM, FTIR, tensile strength, electrical conductivity, water contact angle, UV–visible, hemo-compatibility, and cell culture assessments, are conducted. The SEM images show an average diameter of approximately 166 nm with a smooth surface for PET/MWCNT nanofibers with 10 wt.% PET and 1 wt.% MWCNT. The FTIR results indicate the presence of MWCNT in the nanofibers, with no significant chemical interaction. The electrical conductivity and WCA are measured at 4.08 × 10
–10
S/cm and 120°, respectively. The tensile test reveals an increase in Young’s modulus from 14.6 to 36.6 MPa after MWCNT addition. The inclusion of MWCNT results in an increase of Asp release up to 37%, following the Higuchi model. PET/MWCNT nanofibers reduce platelet adhesion and extend PTT time (up to 40 s) as well as remain hemolysis below 5% compared to PET. This work underscores the potential of electro-spun PET/MWCNT nanofibers with Asp for vascular substitutes.
The rising incidence of breast cancer has been a significant source of concern in the medical community. Regarding the adverse effects and consequences of current treatments, cancers' health, and ...socio-economical aspects have become more complicated, leaving research aimed at improved or new treatments on top priority. Medicinal herbs contain multitarget compounds that can control cancer development and advancement. Owing to Nigella Sativa's elements, it can treat many disorders. Thymoquinone (TQ) is a natural chemical derived from the black seeds of Nigella sativa Linn proved to have anti-cancer and anti-inflammatory properties. TQ interferes in a broad spectrum of tumorigenic procedures and inhibits carcinogenesis, malignant development, invasion, migration, and angiogenesis owing to its multitargeting ability. It effectively facilitates miR-34a up-regulation, regulates the p53-dependent pathway, and suppresses Rac1 expression. TQ promotes apoptosis and controls the expression of pro- and anti-apoptotic genes. It has also been shown to diminish the phosphorylation of NF-B and IKK and decrease the metastasis and ERK1/2 and PI3K activity. We discuss TQ's cytotoxic effects for breast cancer treatment with a deep look at the relevant stimulatory or inhibitory signaling pathways. This review discusses the various forms of polymeric and non-polymeric nanocarriers (NC) and the encapsulation of TQ for increasing oral bioavailability and enhanced in vitro and in vivo efficacy of TQ-combined treatment with different chemotherapeutic agents against various breast cancer cell lines. This study can be useful to a broad scientific community, comprising pharmaceutical and biological scientists, as well as clinical investigators.
Due to the potential positive effects of rosuvastatin (RSV) on human mesenchymal stem cells (MSCs) osteogenesis and new bone regeneration, it is crucial to develop a suitable carrier that can ...effectively control the release profile of RSV. The primary objective of this study was to introduce a novel drug delivery system based on core/shell nanofibrous structures, enabling a sustained release of RSV.
To achieve this, coaxial electrospinning was employed to fabricate chitosan (CS)+polyethylene oxide (PEO)/polycaprolactone (PCL) nanofibrous mats, wherein RSV was incorporated within the core of nanofibers. By optimizing the relevant parameters of the electrospinning process, the mats' surface was further modified using plasma treatment. The fibers' shape, structure, and thermal stability were characterized. The wettability, and degradation properties of the fabricated mats were also examined.
studies were conducted to examine the release behavior of RSV. Additionally, the capability of MSCs to survive and differentiate into osteocytes when cultured on nanofibers containing RSV was evaluated.
Results demonstrated the successful fabrication of CS + PEO + RSV/PCL core/shell mats with a core diameter of approximately 370 nm and a shell thickness of around 70 nm under optimized conditions. Plasma treatment was found to enhance the wettability and drug-release behavior of the mats. The nanofibrous structure, serving as a carrier for RSV, exhibited increased proliferation of MSCs and enhanced osteogenic differentiation.
Therefore, it can be concluded that CS + PEO + RSV/PCL core/shell nanofibrous structure can be utilized as a sustained-release platform for RSV over an extended period, making it a promising candidate for guided bone regeneration.
Application of hyperosmolarity can be a promising strategy to promote chondrogenic differentiation in adipose-derived mesenchymal stem cells (ADSCs). Growth factors may promote different signaling ...pathways in parallel that is why in this study we monitor undesired pathologic or unwanted side effects as well as chondroinductive impacts of hyperosmolarity in differentiating ADSCs. Quantified gene expression, immunocytochemistry, glycosaminoglycan deposition and angiogenic secretion assays performed along with immunoassay. We observed that hyperosmolarity pressure of 480 mOsm over-expressed cartilage specific markers at gene expression level in the extra cellular matrix. Meanwhile, hyperosmolarity of 480 mOsm diminished the expression of cartilage associated pathologic markers, i.e., inflammatory and angiogenic attributes. Certain dose of hyperosmolarity could benefit chondrogenesis in a dual way, first by increasing chondrogenic markers and second by lowering tissue mineralization and angiogenic potential. The chondroprotective potential of hyperosmolarity could have a promising benefit in cartilage cell therapy and tissue engineering.
By screening 27,000 publicly available prokaryotic genomes, we recovered ca. 6300 type I and ca. 5200 type II putative L-asparaginase highlighting the vast potential of prokaryotes. Caspian water ...with similar salt composition to the human serum was targeted for in silico L-asparaginase screening. We screened ca. three million predicted genes of its assembled metagenomes that resulted in annotation of 87 putative L-asparaginase genes. The L-asparagine hydrolysis was experimentally confirmed by synthesizing and cloning three selected genes in E. coli. Catalytic parameters of the purified enzymes were determined to be among the most desirable reported values. Two recombinant enzymes represented remarkable anti-proliferative activity (IC50 <1IU/ml) against leukemia cell line Jurkat while no cytotoxic effect on human erythrocytes or human umbilical vein endothelial cells was detected. Similar salinity and ionic concentration of the Caspian water to the human serum highlights the potential of secretory L-asparaginases recovered from these metagenomes as potential treatment agents.
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•In silico screening finds 87 putative L-asparaginases from brackish Caspian Sea•Three candidate genes, cloned and expressed in E. coli, showed the desired activity•In silico screening coupled with functional validation bypasses cultivation bottleneck
Biological Sciences; Cell Biology; Cancer; In Silico Biology
Vascular tissue engineering is a promising approach for regenerating damaged blood vessels and developing new therapeutic approaches for heart disease treatment. To date, different sources of cells ...have been recognized that offer assistance within the recovery of heart supply routes and veins with distinctive capacities and are compelling for heart regeneration. However, some challenges still remain that need to be overcome to establish the full potential application of these cells. In this paper, we review the different cell sources used for vascular tissue engineering, focusing on extraembryonic tissue-derived cells (ESCs), and elucidate their roles in cardiovascular disease. In addition, we highlight the intricate interplay between mechanical and biochemical factors in regulating mesenchymal stem cell (MSC) differentiation, offering insights into optimizing their application in vascular tissues. Keywords: Vascular tissue regeneration, Extraembryonic tissue-derived cells, perinatal tissues, Stem cells
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