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Liquid biopsies have been receiving tremendous attention for their potential to reshape cancer management. Though current studies of cancer liquid biopsy primarily fucus on applying biochemical assays to characterize the genetic/molecular profiles of circulating tumor cells (CTCs) and their secondary products shed from tumor sites in bodily fluids, delineating the nanomechanical properties of tumor-associated materials in liquid biopsy specimens yields complementary insights into the biology of tumor dissemination and evolution. Particularly, atomic force microscopy (AFM) has become a standard and versatile toolbox for characterizing the mechanical properties of living biological systems at the micro/nanoscale, and AFM has been increasingly utilized to probe the nanomechanical properties of various tumor-derived analytes in liquid biopsies, including CTCs, tumor-associated cells, circulating tumor DNA (ctDNA) molecules, and extracellular vesicles (EVs), offering additional possibilities for understanding cancer pathogenesis from the perspective of mechanobiology. Herein, the applications of AFM in cancer liquid biopsy are summarized, and the challenges and future directions of AFM as a nanomechanical analysis tool in cancer liquid biopsy towards clinical utility are discussed and envisioned.

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SARS-CoV-2 is a highly pathogenic virus responsible for the COVID-19 disease. It belongs to the Coronaviridae family, characterized by a phospholipid envelope, which is crucial for viral entry and replication in host cells. Hypericin, a lipophilic, naturally occurring photosensitizer, was reported to effectively inactivate enveloped viruses, including SARS-CoV-2, upon light irradiation. In addition to its photodynamic activity, Hyp was found to exert an antiviral action also in the dark. This study explores the mechanical properties of heat-inactivated SARS-CoV-2 viral particles using Atomic Force Microscopy (AFM). Results reveal a flexible structure under external stress, potentially contributing to the virus pathogenicity. Although the fixation protocol causes damage to some particles, correlation with fluorescence demonstrates colocalization of partially degraded virions with their genome. The impact of hypericin on the mechanical properties of the virus was assessed and found particularly relevant in dark conditions. These preliminary results suggest that hypericin can affect the mechanical properties of the viral envelope, an effect that warrants further investigation in the context of antiviral therapies.

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OBJECTIVES: To evaluate the effects of dentin biomodification agents (Proanthocyanidin (PAC), Cardol (CD) and Cardol-methacrylate (CDMA) on dentin hydrophilicity by contact angle measurement, viability of dental pulp stem cells (DPSCs) and nanomechanical properties of the hybrid layer (HL). METHODS: CDMA monomer was synthesized from cardol through methacrylic acid esterification. Human extracted third molars were used for all experiments. For nanomechanical tests, specimens were divided in four groups according to the primer solutions (CD, CDMA, PAC and control) were applied before adhesive and composite coating. Nanomechanical properties of the HL were analyzed by nanoindentation test using a Berkovich probe in a nanoindenter. Wettability test was performed on dentin surfaces after 1 min biomodification and measured by contact angle analysis. Cytotoxicity was assessed by a MTT assay with DPSCs after 48 and 72 h. Data were analyzed with Student's t test or Two-way ANOVA and Tukey HSD test (p < 0.05). RESULTS: CD and CDMA solutions achieved greater hydrophobicity and increased the water-surface contact angles when compared to PAC and control groups (p < 0.05). PAC group showed a greater reduction of elastic modulus in nanoindentation experiments when compared to CD and CDMA groups (p < 0.05) after 4 months of aging. CD inhibited cell proliferation compared to all further materials (p < 0.05), whilst CDMA and PAC indicated no cell cytotoxicity to human DPSCs. SIGNIFICANCE: Cardol-methacrylate provided significantly higher hydrophobicity to dentin and demonstrated remarkable potential as collagen crosslinking, attaining the lowest decrease of HL's mechanical properties. Furthermore, such monomer did not affect pulp cytotoxicity, thereby highlighting promising feasibility for clinical applications.

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Refractory metals that can withstand at high temperatures and harsh conditions are of utmost importance for solar-thermal and energy storage applications. Thin films of TiN have been deposited using cathodic vacuum arc deposition at relatively low temperatures ∼300 °C using the substrate bias âˆ¼ -60 V. The nanomechanical properties of these films were investigated using nanoindentation and the spatial fluctuations were observed. The nanoindentation results were simulated using finite element method through Johnson-Cook model. A parametric study was conducted, and 16 different models were simulated to predict the hardening modulus, hardening exponent, and yield stress of the deposited film. The predicted values of elastic modulus, yield stress, hardening modulus and hardening exponent as 246 GPa, 2500 MPa, 25000 MPa and 0.1 respectively are found to satisfactorily explain the experimental load-indentation curves. We have found the local nitridation plays an important role on nanomechanical properties of TiN thin films and confirms that the nitrogen deficient regions are ductile with low yield stress and hardening modulus. This study further opens the opportunities of modelling the nanoscale system using FEM analysis.

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Textile sludge is a by-product produced during the wastewater treatment process in the textile printing and dyeing industry. Textile sludge is rich in heavy metal elements, which makes it a potential risk to the surrounding environment. This study designs a magnesium oxychloride cement (MOC) components to solidify harmful substances in textile sludge and studies the influence of textile sludge ash (TSA) on the mechanical properties and microstructure of MOC samples. The results indicated that adding 5 %-20 % TSA is beneficial for increasing the compressive strength of air-cured MOC paste and improving its water resistance. Meanwhile, the MOC sample shows volume expansion in 168 h, which is related to the further hydration of residual MgO. Incorporating 10 %-20 % TSA substantially increased the volume expansion ratio of the mixture compared to plain MOC sample. In addition, the porosity of TSA-modified MOC after water curing did not change significantly compared to the sample before water curing, while the pore structure of plain MOC after water curing significantly coarsened. This is mainly because TSA reacts with MOC and generates Mg-Al-Cl-Si-H and Mg-Cl-Si-H gels, consequently improving the water stability of MOC sample. At the nanoscale, the 3/5-phase crystal and unreacted MgO content in the 15 % TSA-modified MOC sample is relatively reduced by 7.79 % and 25 %, respectively, compared to the plain sample, but the 13 % gel phase is detected. In addition, the MOC component can effectively solidify heavy metal elements in textile sludge. For the leachate of 20 % TSA-modified MOC paste, the Ni element is not detected, and its solidifying effect on heavy elements such as Zn and Mn exceeded 99 %.

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The combination of the catechol-containing comonomer dopamine methacrylamide (DMA) with stimuli-responsive poly(N-isopropylacrylamide) (PNIPAM) microgels bears a huge potential in research and for applications due to the versatile properties of catechols. This research gives the first detailed insights into the influence of DMA on the swelling of PNIPAM microgels and their nanomechanical properties. Dynamic light scattering measurements showed that DMA decreases the volume phase transition temperature and completion temperature due to its higher hydrophobicity when compared to NIPAM, while sharpening the transition. The cross-linking ability of DMA decreases the swelling ratios and mesh sizes of the microgels. Microgels adsorbed at the solid surface are characterized by atomic force microscopy─as the DMA content increases, microgels protrude more from the surface. Force spectroscopy measurements below and above the volume phase transition temperature display a stiffening of the microgels with the incorporation of DMA and upon heating across its entire cross section as evidenced by an increase in the E modulus. This confirms the cross-linking ability of DMA. The affine network factor ß, derived from the Flory-Rehner theory, is linearly correlated with the E moduli of both pure PNIPAM and P(NIPAM-co-DMA) microgels. However, large DMA amounts hinder the microgel shrinking while maintaining mechanical stiffness, possibly due to catechol interactions within the microgel network.

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Background: Components of diet known as fallback foods are argued to be critical in shaping primate dental anatomy. Such foods of low(er) nutritional quality are often non-preferred, mechanically challenging resources that species resort to during ecological crunch periods. An oft-cited example of the importance of dietary fallbacks in shaping primate anatomy is the grey-cheeked mangabey Lophocebus albigena. This species relies upon hard seeds only when softer, preferred resources are not available, a fact which has been linked to its thick dental enamel. Another mangabey species with thick enamel, the sooty mangabey Cercocebus atys, processes a mechanically challenging food year-round. That the two mangabey species are both thickly-enameled suggests that both fallback and routine consumption of hard foods are associated with the same anatomical feature, complicating interpretations of thick enamel in the fossil record. We anticipated that aspects of enamel other than its thickness might differ between Cercocebus atys and Lophocebus albigena. We hypothesized that to function adequately under a dietary regime of routine hard-object feeding, the molars of Cercocebus atys would be more fracture and wear resistant than those of Lophocebus albigena. Methods: Here we investigated critical fracture loads, nanomechanical properties of enamel, and enamel decussation in Cercocebus atys and Lophocebus albigena. Molars of Cercopithecus, a genus not associated with hard-object feeding, were included for comparison. Critical loads were estimated using measurements from 2D µCT slices of upper and lower molars. Nanomechanical properties (by nanoindentation) and decussation of enamel prisms (by SEM-imaging) in trigon basins of one upper second molar per taxon were compared. Results: Protocone and protoconid critical fracture loads were significantly greater in Cercocebus atys than Lophocebus albigena and greater in both than in Cercopithecus. Elastic modulus, hardness, and elasticity index in most regions of the crown were greater in Cercocebus atys than in the other two taxa, with the greatest difference in the outer enamel. All taxa had decussated enamel, but that of Cercocebus atys uniquely exhibited a bundle of transversely oriented prisms cervical to the radial enamel. Quantitative comparison of in-plane and out-of-plane prism angles suggests that decussation in trigon basin enamel is more complex in Cercocebus atys than it is in either Lophocebus albigena or Cercopithecus cephus. These findings suggest that Cercocebus atys molars are more fracture and wear resistant than those of Lophocebus albigena and Cercopithecus. Recognition of these differences between Cercocebus atys and Lophocebus albigena molars sharpens our understanding of associations between hard-object feeding and dental anatomy under conditions of routine vs. fallback hard-object feeding and provides a basis for dietary inference in fossil primates, including hominins.

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This article focuses on a description of research performed to identify structural and mechanical properties differences between calculi in stones, such as gallstones, kidney stones, dental tartar, and saliva gland sialolite, were analyzed and compared with tap water stone, in order to set interrelations. In this study, biological hard pebble-like structures were analyzed and compared among them using Scanning Electron Microscopy (SEM), X-Ray diffraction (XRD), and Atomic Force Microscopy (AFM). In addition, Nanoindentation was used to obtain values as example in kidney stones the in; stiffness S = 27,827 ± 620 N/nm elastic modulus E = 27.3 ± 4.5 GPa, hardness H = 1.5 ± 0.5 GPa. Samples with the highest amounts of calcium and magnesium oxides were; Tap water stone (39.60%), followed by dental tartar (39.40%), saliva gland sialolite (29.20%), kidney stones (27.70%), and lastly the gallstones (0.30%). Kidney stones showed in particular, whewellite and kaoulinite crystallographic phases, that confers characteristics of greater crystallization with respect to the other stones. Kidney stones positioned in the major hardness stone in human body with 1.5 GPa. In general, samples with the highest amount of calcium oxides, also showed the highest mechanical properties of H and E. Microstructural characteristics and nano-hardness of tap water stone from drinking water where similar to those of dental tartar and saliva gland sialolite, more research still required to associate health concerns and tap water scale derived from drinking water known as hardwater.

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CoFe-based alloys and rare earth (RE) elements are among the most studied materials in applying magnetic devices to improve soft magnetic characteristics. A series of Co40Fe40Sm20 films are deposited on a glass substrate via the sputtering technique, followed by an annealing process to investigate their effect on microstructural and optical properties of Co40Fe40Sm20 films. In this study, the increase in the thickness of Co40Fe40Sm20 films and annealing temperatures resulted in a smoother surface morphology. The 40 nm Co40Fe40Sm20 films annealed 300 °C are expected to have good wear resistance and adhesive properties due to their high values of H/E ratio and surface energy. Optical transparency also increased due to the smoother surface of the Co40Fe40Sm20 films.

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A novel composite based on biocompatible hydroxyapatite (HA) nanoparticles and Cu-HKUST-1 (Cu-HKUST-1@HA) has been prepared following a layer-by-layer strategy. Cu-HKUST-1 was carefully selected from a group of four Cu-based metal-organic frameworks as the material with the most promising antimicrobial activity. The formation of a colloidal Cu-HKUST-1 layer on HA nanoparticles was confirmed by various techniques, e.g., infrared spectroscopy, powder X-ray diffraction, N2 sorption, transmission electron microscopy imaging, electron paramagnetic resonance, and X-ray absorption spectroscopy. Importantly, such a Cu-HKUST-1 layer significantly improved the nanomechanical properties of the composite, with Young's modulus equal to that of human cortical bone (13.76 GPa). At the same time, Cu-HKUST-1@HA has maintained the negative zeta potential (-16.3 mV in pH 7.4) and revealed biocompatibility toward human dermal fibroblasts up to a concentration of 1000 µg/mL, without inducing ex vivo hemolysis. Chemical stability studies of the composite over 21 days in a buffer-simulated physiological fluid allowed a detailed understanding of the transformations that the Cu-HKUST-1@HA undergoes over time. Finally, it has been confirmed that the Cu-HKUST-1 layer provides antibacterial properties to HA, and the synergism reached in this way makes it promising for bone tissue regeneration.

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The armour of the ladybird, elytra, protect the body from injury and are well-adapted to flight. However, experimental methods to decipher their mechanical performances had been challenging due to the small size, making it unclear how the elytra balance mass and strength. Here, we provide insights to the relationship between the microstructure and multifunctional properties of the elytra by means of structural characterization, mechanical analysis and finite element simulations. Micromorphology analysis on the elytron revealed the thickness ratio of the upper lamination, middle layer and lower lamination is approximately 51:139:7. The upper lamination had multiple cross fibre layers and the thickness of each fibre layer is not the same. In addition, the tensile strength, elastic modulus, fracture strain, bending stiffness and hardness of elytra were obtained through in-situ tensile and nanoindentation-bending under the influence of multiple loading conditions, which also serve as references for finite element models. The finite element model revealed that structural factors such as thickness of each layer, angle of fibre layer and trabeculae are key to affecting the mechanical properties, but the effect is different. When the thickness of upper, middle and lower layers is the same, the tensile strength provided by unit mass of the model is 52.78% lower than that provided by elytra. These findings broaden the relationship between the structural and mechanical properties of the ladybird elytra, and are expected to inspire the development of sandwich structures in biomedical engineering.

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Laser surface alloying with WC particles was used in order to improve the wear resistance of Inconel®600-alloy. The applied processing parameters ensured appropriate conditions for the production of composite layers enriched with WC particles that did not melt during the process. As a consequence, the produced layers contained globular shaped WC particles that were well bonded in the matrix. The WC particles were characterized by high hardness HIT = 31.25 GPa and a high Young's modulus EIT = 609.33 GPa determined by nanoindentation. The most important parameter influencing the thickness of the layer, the percentage of WC particles in the layer and the wear resistance of the produced layers was the power of the laser beam. Three values of laser beam power were used: 1.3 kW, 1.56 kW, and 1.82 kW. An increase in the laser beam power resulted in an increased thickness of the layer from 435 µm to 685 µm. Simultaneously, when the power of the laser beam was higher, the depth of re-melting of the substrate material increased. This was the reason for a decrease in the percentage of WC particles in the composite layer. The layer produced by laser beam power of 1.3 kW contained 20.59% of WC particles, whereas the highest power of the laser beam (1.82 kW) ensured a percentage of WC particles of about 9.46%. As a result, the increase in the laser beam power was the reason for the reduction in the wear resistance of the composite layer. The lowest mass wear intensity factor (Imw = 6.4 mg·cm-2·h-1) characterized the layer produced at laser beam power of 1.3 kW, and the highest Imw (18.5 mg·cm-2·h-1) was obtained for the layer produced with a laser beam power of 1.82 kW. However, all the produced composite layers contained WC particles, which ensured improved wear resistance when compared to the Inconel®600-alloy without the layer (Imw = 60.9 mg·cm-2·h-1).

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The synthesis of x-wt.% (where x = 2.5, 5, 7.5, and 10) TiB2-reinforced titanium matrix was accomplished through the spark plasma sintering technique (SPS). The sintered bulk samples were characterized, and their mechanical properties were evaluated. Near full density was attained, with the sintered sample having the least relative density of 97.5%. This indicates that the SPS process aids good sinterability. The Vickers hardness of the consolidated samples improved from 188.1 HV1 to 304.8 HV1, attributed to the high hardness of the TiB2. The tensile strength and elongation of the sintered samples decreased with increasing TiB2 content. The nano hardness and reduced elastic modulus of the consolidated samples were upgraded due to the addition of TiB2, with the Ti-7.5 wt.% TiB2 sample showing the maximum values of 9841 MPa and 188 GPa, respectively. The microstructures display the dispersion of whiskers and in-situ particles, and the X-ray diffraction analysis (XRD) showed new phases. Furthermore, the presence of TiB2 particles in the composites enhanced better wear resistance than the unreinforced Ti sample. Due to dimples and large cracks, ductile and brittle fracture behavior was noticed in the sintered composites.

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Cells release extracellular vesicles (EVs) as the carriers for intercellular communications to regulate life activities. Particularly, it is increasingly apparent that mechanical forces play an essential role in biological systems. The nanomechanical properties of EVs and their dynamics in cancer development are still not fully understood. Herein, with the use of atomic force microscopy (AFM), the nanomechanical signatures of EVs from the liquid biopsies of hematologic cancer patients were unraveled. Single native EVs were probed by AFM under aqueous conditions. The elastic and viscous properties of EVs were measured and visualized to correlate EV mechanics with EV geometry. Experimental results remarkably reveal the significant differences in EV mechanics among multiple myeloma patients, lymphoma patients, and healthy volunteers. The study unveils the unique nanomechanical signatures of EVs in hematologic cancers, which will benefit the studies of liquid biopsies for cancer diagnosis and prognosis with translational significance.

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HYPOTHESIS: Virus-like particles (VLPs) are promising scaffolds for developing mucosal vaccines. For their optimal performance, in addition to design parameters from an immunological perspective, biophysical properties may need to be considered. EXPERIMENTS: We investigated the mechanical properties of VLPs scaffolded on the coat protein of Acinetobacter phage AP205 using atomic force microscopy and small angle X-ray scattering. FINDINGS: Investigations showed that AP205 VLP is a tough nanoshell of stiffness 93 ± 23 pN/nm and elastic modulus 0.11 GPa. However, its mechanical properties are modulated by attaching muco-inert polyethylene glycol to 46 ± 10 pN/nm and 0.05 GPa. Addition of antigenic peptides derived from SARS-CoV2 spike protein by genetic fusion increased the stiffness to 146 ± 54 pN/nm although the elastic modulus remained unchanged. These results, which are interpreted in terms of shell thickness and coat protein net charge variations, demonstrate that surface conjugation can induce appreciable changes in the biophysical properties of VLP-scaffolded vaccines.

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In this work, the formation of laser-induced periodic surface structures (LIPSS) on the surfaces of thin films of poly(ethylene terephthalate) (PET) and PET reinforced with expanded graphite (EG) was studied. Laser irradiation was carried out by ultraviolet (265 nm) and near-infrared (795 nm) femtosecond laser pulses, and LIPSS were formed in both materials. In all cases, LIPSS had a period close to the irradiation wavelength and were formed parallel to the polarization of the laser beam, although, in the case of UV irradiation, differences in the formation range were observed due to the different thermal properties of the neat polymer in comparison to the composite. To monitor the modification of the physicochemical properties of the surfaces after irradiation as a function of the laser wavelength and of the presence of the filler, different techniques were used. Contact angle measurements were carried out using different reference liquids to measure the wettability and the solid surface free energies. The initially hydrophilic surfaces became more hydrophilic after ultraviolet irradiation, while they evolved to become hydrophobic under near-infrared laser irradiation. The values of the surface free energy components showed changes after nanostructuring, mainly in the polar component. Additionally, for UV-irradiated surfaces, adhesion, determined by the colloidal probe technique, increased, while, for NIR irradiation, adhesion decreased. Finally, nanomechanical properties were measured by the PeakForce Quantitative Nanomechanical Mapping method, obtaining maps of elastic modulus, adhesion, and deformation. The results showed an increase in the elastic modulus in the PET/EG, confirming the reinforcing action of the EG in the polymer matrix. Additionally, an increase in the elastic modulus was observed after LIPSS formation.

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Poly(ethylene 2,5-furandicarboxylate) (PEF) nanocomposites reinforced with various content of graphene nanoplatelets (GNPs) were synthesized in situ in this work. PEF is a widely known biobased polyester with promising physical properties and is considered as the sustainable counterpart of PET. Despite its exceptional gas barrier and mechanical properties, PEF presents with a low crystallization rate. In this context, a small number of GNPs were incorporated into the material to facilitate the nucleation and overall crystallization of the matrix. Kinetic analysis of both the cold and melt crystallization processes of the prepared materials was achieved by means of differential scanning calorimetry (DSC). The prepared materials' isothermal crystallization from the glass and melt states was studied using the Avrami and Hoffman-Lauritzen theories. The Dobreva method was applied for the non-isothermal DSC measurements to calculate the nucleation efficiency of the GNPs on the PEF matrix. Furthermore, Vyazovkin's isoconversional method was employed to estimate the effective activation energy values of the amorphous materials' glass transition. Finally, the nanomechanical properties of the amorphous and semicrystalline PEF materials were evaluated via nanoindentation measurements. It is shown that the GNPs facilitate the crystallization process through heterogeneous nucleation and, at the same time, improve the nanomechanical behavior of PEF, with the semicrystalline samples presenting with the larger enhancements.

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The differences in bone nanomechanical properties between cortical (Ct) and trabecular (Tb) bone remain uncertain, whereas knowing the respective contribution of each compartment is critical to understand the origin of bone strength. Our purpose was to compare bone mechanical and intrinsic properties of Ct and Tb compartments, at the bone structural unit (BSU) level, in iliac bone taken from a homogeneous untreated human population. Among 60 PMMA-embedded transiliac bone biopsies from untreated postmenopausal osteoporotic women (64 ± 7 year-old), >2000 BSUs were analysed by nanoindentation in physiological wet conditions [indentation modulus (elasticity), hardness, dissipated energy], by Fourier transform infrared (FTIRM) and Raman microspectroscopy (mineral and organic characteristics), and by X-ray microradiography (degree of mineralization of bone, DMB). BSUs were categorized based on tissue age, osteonal (Ost) and interstitial (Int) tissues location and bone compartments (Ct and Tb). Indentation modulus was higher in Ct than in Tb BSUs, both in Ost and Int. dissipated energy was higher in Ct than Tb, in Int BSUs. Hardness was not different between Ct and Tb BSUs. In Ost or Int BSUs, mineral maturity (conversion of non-apatitic into apatitic phosphates) was higher in Ct than in Tb, as well as for collagen maturity (Ost). Mineral content assessed as mineral/matrix (FTIRM and Raman) or as DMB, was lower in Ct than in Tb. Crystallinity (FTIRM) was similar in BSUs from Ct and Tb, and slightly lower in Ct than in Tb when measured by Raman, indicating that the crystal size/perfection was quite similar between Ct and Tb BSUs. The differences found between Ost and Int tissues were much higher than the difference found between Ct and Tb for all those bone material properties. Multiple regression analysis showed that Indentation modulus and dissipated energy were mainly explained by mineral maturity in Ct and by collagen maturity in Tb, and hardness by mineral content in both Ct and Tb. In conclusion, in untreated human iliac bone, Ct and Tb BSUs exhibit different characteristics. Ct BSUs have higher indentation modulus, dissipated energy (Int), mineral and organic maturities than Tb BSUs, without difference in hardness. Although those differences are relatively small compared to those found between Ost and Int BSUs, they may influence bone strength at macroscale.

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The important issue associated with the design and the fabrication of the titanium and titanium alloy implants is the increase of their biointegration with bone tissue. In the presented paper, the research results concerning the conditions used in the cathodic deposition of hydroxyapatite on the surface Ti6Al4V substrates primarily modified by the production of TiO2 nanoporous coatings, TiO2 nanofibers, and titanate coatings, are discussed. Despite excellent biocompatibility with natural bone tissue of materials based on hydroxyapatite (HA), their poor adhesion to the substrate caused the limited use in the implants' construction. In our works, we have focused on the comparison of the structure, physicochemical, and mechanical properties of coating systems produced at different conditions. For this purpose, scanning electron microscopy images, chemical composition, X-ray diffraction patterns, infrared spectroscopy, wettability, and mechanical properties are analyzed. Our investigations proved that the intermediate titanium oxide coatings presence significantly increases the adhesion between the hydroxyapatite layer and the Ti6Al4V substrate, thus solving the temporary delamination problems of the HA layer.

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We report on tungsten disulfide (WS2) flakes grown by chemical vapor deposition (CVD), which exhibit a flower-like surface structure above the primary few-layer flake with a triangular shape. The fine structure is only revealed in the mechanical, chemical, and electronic properties of the flake but not in the topography. The origin of this structure is the peculiar one-step growth during the CVD process that permits to control the sulfur concentration at any time. A high concentration of S at the onset of the deposition process leads to a rapid growth of the flake, resulting in tungsten vacancies. Reducing the sulfur concentration toward the end of the growth slows down the reaction and leads to sulfur vacancies. These microscale domains were studied by confocal- and tip-enhanced Raman spectroscopy revealing their chemical composition with high spatial resolution. A strong quenching of the photoluminescence in the tungsten-vacancy domains is observed. Atomic force microscope measurements, performed in intermittent contact mode, force modulation mode (including lateral force mode), and PeakForce quantitative nanomechanics mode, show that the mechanical properties of these domains differ. Within the tungsten-vacancy domains, the adhesion force is reduced, while the friction force increased. Kelvin probe force microscopy measurements show that the electronic properties of the flakes are modulated by these domains. The combined nanomechanical and nanospectroscopy measurements provide detailed insights on the inhomogeneous surface properties of the single WS2 flake, further highlighting how its multidomain properties can be finely tuned using CVD.