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The Effect of Laser Structuring of Carbon Nanotubes on the Proliferation of Chondroblasts and Mesenchymal Stem Cells
摘要： The density of cartilage cells (chondroblasts) proliferating on a silicon substrate coated with vertically oriented arrays of multi-walled carbon nanotubes (MWCNTs) was shown to be higher than on a pure silicon substrate. Electron microscopy showed that the cells in a nutrient medium affected the vertical position of the nanotubes in the array. A method for structuring the MWCNT arrays by 100-ns laser pulse scanning and abrasive water processing on planar substrates was developed. As a result of the structuring of the MWCNTs, the arrays become resistant to bending under the influence of the nutrient medium with mesenchymal stem cells. Structured MWCNT arrays were shown to have no toxic or pathological effect on the viability and morphology of stem cells. Thus, such materials can be suggested for use in cell-adhesive components of biomedical devices.
关键词： carbon nanotubes,laser structuring,mesenchymal stem cells,chondroblasts,cell proliferation
更新于2025-09-19 17:13:59
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Development of an anti-CD45RA-quantum dots conjugated scFv to detect leukemic cancer stem cells
摘要： Leukemic cancer stem cells (LSCs), aberrantly overexpressing CD45RA are among the major causes of relapse following chemotherapy in patients with acute myeloid leukemia and serve as a highly sensitive marker for predicting relapse occurrence following chemotherapy. The main purpose of current study was to develop a sensitive approach for detecting LSCs based on a conjugate of an anti-CD45 scFv and quantum dot. The variable light and heavy chain sequences of a recently developed anti-CD45RA monoclonal antibody were derived from hybridoma cells and PCR amplified to construct scFv. Following insertion of scFv gene into a pET32a-lic vector and expression in Escherichia coli and purification, the purified scFv, was conjugated with carbon dots (C dots) and used for the detection of CD45RA +cells while CD45RA-cells served as negative control. Subsequently, Functional activity of the conjugate was analyzed by flow cytometry and ICC to detect the cell surface antigen binding and detection ability. Based on results, purified CD45RA scFv conjugated C dots could specifically recognize CD45RA positive cells, but not any CD45RA negative ones. In conclusion, here we developed a low-cost but very efficient approach for detection of CD45RA positive cells including LSCs.
关键词： CD45RA,Leukemic cancer stem cell,scFv,AML,Carbon dots,Conjugation
更新于2025-09-19 17:13:59
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ESTIMATING SINGLE TREE STEM AND BRANCH BIOMASS USING TERRESTRIAL LASER SCANNING
摘要： This paper presents a novel non-destructive approach for individual tree stem and branch biomass estimation using terrestrial laser scanning data. The study area is located at the Royal Belum Reserved Forest area, Gerik, Perak. Each forest plot was designed with a circular shape and contains several scanning locations to ensure good visibility of each tree. Unique tree signage was located on trees with diameter at breast height (DBH) of 10cm and above. Extractions of individual trees were done manually and the matching process with the field collected tree properties were relied on the tree signage and tree location as collected by total station. Individual tree stems were reconstructed based on cylinder models from which the total stem volume was calculated. Biomass of individual tree stems was calculated by multiplying stem volume with specific wood density. Biomass of individual was estimated using similar concept of tree stem with the volume estimated from alpha-hull shape. The root mean squared errors (RMSE) of estimated biomass are 50.22kg and 27.20kg for stem and branch respectively.
关键词： Terrestrial laser scanner,stem and branch biomass
更新于2025-09-19 17:13:59
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893 Low-level laser therapy for the treatment of male and female-pattern hair loss: A review of literature
摘要： Gain-of-function mutations in TRPV3 can result in Olmsted syndrome, characterized by palmoplantar and periorificial keratoderma, itch, and hair loss. The mechanisms underlying these phenotypes are unclear. Here, we engineered the first knock-in mouse model of Trpv3 by introducing a point mutation analogous to that (G568V) found in Olmsted syndrome patients. Homozygous Trpv3 knock-in (Trpv3G568V/G568V) mice exhibit sparse hair within two weeks after birth. Histologically, hair shafts in Trpv3G568V/G568V mice are twisted in the infundibulum, unable to penetrate the skin. Immunofluorescence demonstrated impaired inner root sheath cell differentiation as trichohyalin and KRT71 were diminished in mutant hair follicles. These abnormalities are consistent with the expression pattern of Trpv3, which is predominantly in the proximal region of inner root sheath as demonstrated by in situ hybridization and in a Trpv3 reporter mouse model we engineered. The hair loss phenotype is progressive, and is associated with the lack of typical telogen. After three hair cycles, Trpv3G568V/G568V mice became completely bald. Aberrantly increased proliferation and ectopic expression of epidermal markers, including KRT1 and loricrin, are characteristic of degenerating hair follicles in Trpv3G568V/G568V mice, which gradually lose stem cells, as marked by CD34, NFATc1 and KRT15, and the typical structure of a hair follicle. Findings from this study suggest that Trpv3 is an important regulator of inner root sheath keratinocyte differentiation, whereas hair loss associated with gain-of-function mutations in Trpv3 is caused by impaired proliferation and differentiation programs, leading to the exhaustion of follicular keratinocyte stem cells, and permanent disruption of the hair follicles.
关键词： keratinocyte differentiation,TRPV3,Olmsted syndrome,stem cells,hair loss
更新于2025-09-16 10:30:52
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Effects of freezing on mesenchymal stem cells labeled with gold nanoparticles
摘要： Stem cell therapies are a promising treatment for many patients suffering from diseases with poor prognosis. However, clinical translation is inhibited by a lack of in vivo monitoring techniques to track stem cells throughout the course of treatment. Ultrasound-guided photoacoustic imaging of nanoparticle-labeled stem cells may be a solution. To allow photoacoustic tracking, stem cells must be labeled with an optically absorbing contrast agent. Gold nanoparticles are one option due to their cytocompatibility and strong optical absorption in the near-infrared region. However, stem cell labeling can require up to 24-hour incubation with nanoparticles in culture prior to use. Although stem cell monitoring is critically needed, the additional preparation time may not be feasible – it is cost prohibitive and stem cell treatments should be readily available in emergency situations as well as scheduled procedures. To remedy this, stem cells can be labeled prior to freezing and long-term storage. While it is well known that stem cells retain their cellular function after freezing, storage, and thawing, the impact of gold nanoparticles on this process has yet to be investigated. Therefore, we assessed the viability, multipotency, and photoacoustic activity of gold nanosphere-labeled mesenchymal stem cells after freezing, storage, and thawing for one week, one month, or two months and compared to unlabeled, na?ve mesenchymal stem cells which were frozen, stored, and thawed at the same time points. Results indicated no substantial change in viability as assessed by the MTT assay. Differentiation, observed through adipogenesis and osteogenesis, was also comparable to controls. Lastly, strong photoacoustic signals and similar photoacoustic spectral signatures remained. Further studies involving more diverse stem cell types and nanoparticles are required, but our data suggests that function and imaging properties of nanoparticle-labeled stem cells are maintained after freezing and storage, which improves translation of stem cell monitoring techniques by simplifying integration with clinical protocols.
关键词： photoacoustic imaging,cell tracking,freezing,Gold nanospheres,ultrasound,stem cells
更新于2025-09-16 10:30:52
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Dual-Modal Imaging-Guided Precise Tracking of Bioorthogonally Labeled Mesenchymal Stem Cells in Mouse Brain Stroke
摘要： Non-invasive and precise stem cell tracking after transplantation in living subject is very important to monitor both stem cell destinations and their in vivo fate, which was closely related to their therapeutic efficacy. Herein, we developed bicyclo[6.1.0]nonyne (BCN)-conjugated glycol chitosan nanoparticles (BCN-NPs) as a delivery system of dual-modal stem cell imaging probes. Near-infrared fluorescent (NIRF) dye, Cy5.5, was chemically conjugated to the BCN-NPs and then oleic acid-coated superparamagnetic iron oxide nanoparticles (OA-Fe3O4 NPs) were encapsulated into BCN-NPs, in resulting Cy5.5-labeled and OA-Fe3O4 NP-encapsulated BCN-NPs (BCN-dual-NPs). For bioorthogonal labeling of human adipose-derived mesenchymal stem cells (hMSCs), firstly, hMSCs were treated with tetra-acetylated N-azidoacetyl-D-mannosamine (Ac4ManNAz) for generating azide (-N3) groups onto their surface via metabolic glycoengineering. Second, azide groups on the cell surface were successfully chemically labeled with BCN-dual-NPs via bioorthogonal click chemistry in vitro. This bioorthogonal labeling of hMSCs could greatly increase the cell labeling efficiency, safety, and imaging sensitivity, compared to only nanoparticle-derived labeling technology. The dual-modal imaging-guided precise tracking of bioorthogonally labeled hMSCs was tested in the photothrombotic stroke mouse model via intraparenchymal injection. Finally, BCN-dual-NPs-labeled hMSCs could be effectively tracked of their migration from implanted site to brain stroke lesion using NIRF/T2-weighted magnetic resonance (MR) dual-modal imaging for 14 days. Our observation would provide a potential application of bioorthogonally labeled stem cell imaging in regenerative medicine by providing safety and high labeling efficiency in vitro and in vivo.
关键词： metabolic engineering,dual-modal imaging,bioorthogonal click chemistry,stem cell tracking,imaging probe,brain stroke
更新于2025-09-16 10:30:52
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Spatially Controlled Fabrication and Mechanisms of Atomically Thin Nanowell Patterns in Bilayer WS <sub/>2</sub> Using <i>in Situ</i> High Temperature Electron Microscopy
摘要： We show controlled production of atomically thin nanowells in bilayer WS2 using an in situ heating holder combined with a focused electron beam in a scanning transmission electron microscope (STEM). We systematically study the formation and evolvement mechanism involved in removing a single layer of WS2 within a bilayer region with 2 nm accuracy in location and without punching through to the other layer to create a hole. Best results are found when using a high temperature of 800 °C, because it enables thermally activated atomic migration and eliminates the interference from surface carbon contamination. We demonstrate precise control over spatial distributions with 5 nm accuracy of patterning and the width of nanowells adjustable by dose-dependent parameters. The mechanism of removing a monolayer of WS2 within a bilayer region is different than removing equivalent sections in a monolayer film due to the van der Waals interaction of the underlying remaining layer in the bilayer system that stabilizes the excess W atom stoichiometry within the edges of the nanowell structure and facilitates expansion. This study offers insights for the nanoengineering of nanowells in two-dimensional (2D) transitional metal dichalcogenides (TMDs), which could hold potential as selective traps to localize 2D reactions in molecules and ions, underpinning the broader utilization of 2D material membranes.
关键词： bilayer TMDs,nanowells,in situ STEM,nanopores,2D materials
更新于2025-09-12 10:27:22
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Long-term results of isolated transmyocardial laser revascularization in combination with the intramyocardial autologous bone marrow stem cells injection
摘要： To evaluate the long-term results of TMLR using a CO2 laser in combination with intramyocardial injection of ABMSC as an isolated procedure in patients with the end-stage coronary artery disease, the study included 20 patients (90% male), with a mean age of 58.4 ± 8.7 years. To assess the long-term results, patients were examined in a hospital. The Minnesota Living with Heart Failure Questionnaire (MLHFQ) and the Seattle Angina Questionnaire (SAQ) were used. The evolution of laboratory and instrumental indices, as well as medical therapy, was assessed. The end points of the study were death, acute myocardial infarction (AMI), repeated myocardial revascularization, recurrent hospitalizations due to coronary artery disease, and stroke. The changes in angina functional class were also evaluated. The median of follow-up period was 54 (36; 83) months, that is, 4.5 years. The analysis of the evolution of echocardiographic data showed the absence of statistically significant changes in the following parameters: left ventricular end-diastolic diameter (EDD) (p = 0.967), end-systolic diameter (ESD) (p = 0.204), end-diastolic volume (EDV) (p = 0.852), end-systolic volume (ESV) (p = 0.125), and left ventricular ejection fraction (LVEF) (p = 0.120). The patients continued to regularly take the main groups of medications. Nitrate consumption was significantly reduced (p < 0.001). Significant positive dynamics were observed in the changes in angina functional class. At the baseline, all patients had angina III FC, in the long term, 3 patients had II FC, 11 patients had I FC, and 6 patients had no angina. Clinical outcomes (mortality, recurrent myocardial infarction, stroke) were absent during the follow-up period. There were two cases of repeated myocardial revascularization. Regression analysis revealed that SYNTAX score was associated with the clinical outcome “repeated revascularization.” TMLR in combination with intramyocardial injection of ABMSC is a safe method to achieve a statistically significant antianginal effect and reduce the need for “nitrates,” which in turn improves the quality of life and reduces the frequency of hospitalizations due to coronary artery disease. These results can be achieved with strict adherence to the certain indications for the intervention.
关键词： Coronary artery disease,Transmyocardial laser myocardial revascularization,Autologous bone marrow stem cells,Chronic heart failure,CO2 laser
更新于2025-09-12 10:27:22
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Dual-Enhanced Raman Scattering-Based Characterization of Stem Cell Differentiation Using Graphene-Plasmonic Hybrid Nanoarray
摘要： Surface-enhanced Raman scattering (SERS) has demonstrated great potential to analyze a variety of bio/chemical molecular interactions within cells in a highly sensitive and selective manner. Despite significant advancements, it remains a critical challenge to ensure high sensitivity and selectivity, while achieving uniform signal enhancement and high reproducibility for quantitative detection of targeted biomarkers within a complex stem cell microenvironment. Herein, we demonstrate an innovative sensing platform, using graphene-coated homogeneous plasmonic metal (Au) nanoarrays, which synergize both electromagnetic mechanism (EM)- and chemical mechanism (CM)-based enhancement. Through the homogeneous plasmonic nanostructures, generated by laser interference lithography (LIL), highly reproducible enhancement of Raman signals could be obtained via a strong and uniform EM. Additionally, the graphene-functionalized surface simultaneously amplifies the Raman signals by an optimized CM, which aligns the energy level of the graphene oxide with the target molecule by tuning its oxidation levels, consequently increasing the sensitivity and accuracy of our sensing system. Using the dual-enhanced Raman scattering from both EM from the homogeneous plasmonic Au nanoarray and CM from the graphene surface, our graphene?Au hybrid nanoarray was successfully utilized to detect as well as quantify a specific biomarker (TuJ1) gene expression levels to characterize neuronal differentiation of human neural stem cells (hNSCs). Collectively, we believe our unique graphene?plasmonic hybrid nanoarray can be extended to a wide range of applications in the development of simple, rapid, and accurate sensing platforms for screening various bio/chemical molecules.
关键词： DNA detection,Surface-enhanced Raman scattering,biosensing,stem cell differentiation,2D nanomaterials
更新于2025-09-12 10:27:22
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Analysis of stand density effects on the stem form of Norway spruce trees and volume miscalculation by traditional form factor equations using terrestrial laser scanning (TLS)
摘要： Tree and stand volume estimates are relevant for forest inventories, forest sales and carbon stock evaluations. Forest practice commonly uses generalized stem wood volume functions. However, such generalized approaches neglect the stem form in detail. Hence, trees of a given species with the same diameter at breast height (??1.3) and height (h) are always assumed to have the same form factor and thus the same volume. This case study focused on stem form variation of Picea abies due to competition effects. Using terrestrial laser scanning (TLS), we measured the stem shape of 868 trees from a long-term spacing and thinning experiment in Germany. The plots covered a broad density range. We analysed the effect of competition and compared the TLS- with conventionally determined stem volume estimates. TLS-based volume estimations showed that the lower the competition, the lower the tree volume with a given ??1.3 and h. Commonly used functions underestimated the volume stock overall by 4.2 %, disregarding any levels. At plot level, underestimation varied from 0.7 to 7.0 %. At tree level, the volume was over- and underestimated by -10 to +10 %. The more precise the examination, the more suitable the application of TLS for enhancing volume estimation.
关键词： stem wood,volume function,form factor,competition,Tree and stand volume
更新于2025-09-12 10:27:22