Mechanically suitable and osteoinductive 3D-printed composite scaffolds with hydroxyapatite nanoparticles having diverse morphologies for bone tissue engineering.

The challenge of integrating hydroxyapatite nanoparticles (nHAp) with polymers is hindered by the conflict between the hydrophilic and hygroscopic properties of nHAp and the hydrophobic properties of polymers. This conflict particularly affects the materials when calcium phosphates, including nHAp, are used as a filler in composites in thermal processing applications such as 3D printing with fused filament fabrication (FFF). To overcome this, we propose a one-step surface modification of nHAp with calcium stearate monolayer. Moreover, to build the scaffold with suitable mechanical strength, we tested the addition of nHAp with diverse morphology-spherical, plate- and rod-like nanoparticles. Our analysis showed that the composite of polycaprolactone (PCL) reinforced with nHAp with rod and plate morphologies modified with calcium stearate monolayer exhibited a significant increase in compressive strength. However, composites with spherical nHAp added to PCL showed a significant reduction in compressive modulus and compressive strength, but both parameters were within the applicability range of hard tissue scaffolds. None of the tested composite scaffolds showed cytotoxicity in L929 murine fibroblasts or MG-63 human osteoblast-like cells, supporting the proliferation of the latter. Additionally, PCL/nHAp scaffolds reinforced with spherical nHAp caused osteoactivation of bone marrow human mesenchymal stem cells, as indicated by alkaline phosphatase activity and COL1, RUNX2, and BGLAP expression. These results suggest that the calcium stearate monolayer on the surface of the nHAp particles allows the production of polymer/nHAp composites suitable for hard tissue engineering and personalized implant production in 3D printing using the FFF technique.

Surface-Constrained Metropolis Monte Carlo: Simulation of Reactions on Triply Periodic Minimal Surfaces.

Triply periodic minimal surfaces (TPMS) inspired by nature serve as a foundation for developing novel nanomaterials, such as templated silicas, graphene sponges, and schwarzites, with customizable optical, poroelastic, adsorptive, catalytic, and other properties. Computer simulations of reactions on TPMS using reactive intermolecular potentials hold great promise for constructing and screening potential TPMS with the desired properties. Here, we developed an off-lattice, surface-constrained Metropolis Monte Carlo (SC-MMC) algorithm that utilized a temperature quench process. The presented SC-MMC algorithm was used to investigate the process of graphitization reactions on the Schwarz primitive, Schwarz diamond, and Schoen gyroid TPMS, all with a cubic lattice parameter of 8 nm. We show that the optimized carbon TPMS exhibits a low energy, approximately -7.1 eV/atom, comparable to that of graphite and diamond crystals, along with a variety of topological defects. Furthermore, these structures showcase extensive and smooth surfaces characterized by a negative discrete Gaussian curvature, a distinctive feature indicative of an interconnected morphology. They possess specific surface areas of ∼2700 m2/g, comparable to graphene, and exhibit a significant porosity of around 90%. The theoretical X-ray correlation functions and nitrogen adsorption isotherms confirm that the constructed TPMS exhibit remarkably similar surface properties, although the pore space topology varies significantly.

Isolation and identification of microplastics in infant formulas - A potential health risk for children.

Microplastics (MPs) are plastic particles between 0.1 and 5,000 µm in size that can contaminate food. Unfortunately, to date, little attention has been paid to analyzing the presence of such particles in baby foods. The present study aimed to determine the degree of contamination of infant formula with MPs. A total of thirty products were subjected to analysis. The research methodology used included the isolation of plastic particles, identification and characterization of MPs using advanced microscopic and spectroscopic techniques. Microplastics were detected in all tested samples. The most frequently identified polymers were polyamide, polyethylene, polypropylene, and poly(ethylene terephthalate). The particles exhibited diverse forms, including fibers, fragments, and films, displaying a range of colors such as colorless, black, and brown particles. Furthermore, the daily intake of MPs by children fed exclusively infant formula was estimated to be approximately 49 ± 32 MPs. This poses a potential health risk for the youngest.

Microfluidic-Assisted Formulation of ε-Polycaprolactone Nanoparticles and Evaluation of Their Properties and In Vitro Cell Uptake.

The nanoprecipitation method was used to formulate ε-polycaprolactone (PCL) into fluorescent nanoparticles. Two methods of mixing the phases were evaluated: introducing the organic phase into the aqueous phase dropwise and via a specially designed microfluidic device. As a result of the nanoprecipitation process, fluorescein-loaded nanoparticles (NPs) with a mean diameter of 127 ± 3 nm and polydispersity index (PDI) of 0.180 ± 0.009 were obtained. The profiles of dye release were determined in vitro using dialysis membrane tubing, and the results showed a controlled release of the dye from NPs. In addition, the cytotoxicity of the NPs was assessed using an MTT assay. The PCL NPs were shown to be safe and non-toxic to L929 and MG63 cells. The results of the present study have revealed that PCL NPs represent a promising system for developing new drug delivery systems.

Composite microgranular scaffolds with surface modifications for improved initial osteoblastic cell proliferation.

Polyester-based granular scaffolds are a potent material for tissue engineering due to their porosity, controllable pore size, and potential to be molded into various shapes. Additionally, they can be produced as composite materials, e.g., mixed with osteoconductive ß-tricalcium phosphate or hydroxyapatite. Such polymer-based composite materials often happen to be hydrophobic, which disrupts cell attachment and decreases cell growth on the scaffold, undermining its primary function. In this work, we propose the experimental comparison of three modification techniques for granular scaffolds to increase their hydrophilicity and cell attachment. Those techniques include atmospheric plasma treatment, polydopamine coating, and polynorepinephrine coating. Composite polymer/ß-tricalcium phosphate granules have been produced in a solution-induced phase separation (SIPS) process using commercially available biomedical polymers: poly(lactic acid), poly(lactic-co-glycolic acid), and polycaprolactone. We used thermal assembly to prepare cylindrical scaffolds from composite microgranules. Atmospheric plasma treatment, polydopamine coating, and polynorepinephrine coating showed similar effects on polymer composites' hydrophilic and bioactive properties. All modifications significantly increased human osteosarcoma MG-63 cell adhesion and proliferation in vitro compared to cells cultured on unmodified materials. In the case of polycaprolactone/ß-tricalcium phosphate scaffolds, modifications were the most necessary, as unmodified polycaprolactone-based material disrupted the cell attachment. Modified polylactide/ß-tricalcium phosphate scaffold supported excellent cell growth and showed ultimate compressive strength exceeding this of human trabecular bone. This suggests that all investigated modification techniques can be used interchangeably for increasing wettability and cell attachment properties of various scaffolds for medical applications, especially those with high surface and volumetric porosity, like granular scaffolds.

Low-density 3D-printed boluses with honeycomb infill in radiotherapy.

PURPOSE: Dosimetric characteristics of 3D-printed plates using different infill percentage and materials was the purpose of our study. METHODS: Test plates with 5%, 10%, 15% and 20% honeycomb structure infill were fabricated using TPU and PLA polymers. The Hounsfield unit distribution was determined using a Python script. Percentage Depth Dose (PDD) distribution in the build-up region was measured with the Markus plane-parallel ionization chamber for an open 10x10 cm2 field of 6 MV. PDD was measured at a depth of 1 mm, 5 mm, 10 mm and 15 mm. Measurements were compared with Eclipse treatment planning system calculations using AAA and Acuros XB algorithms. RESULTS: The mean HU for CT scans of 3D-printed TPU plates increased with percentage infill increase from -739 HU for 5% to -399 HU for 20%. Differences between the average HU for TPU and PLA did not exceed 2% for all percentage infills. Even using a plate with the lowest infill PDD at 1 mm depth increase from 44.7% (without a plate) to 76.9% for TPU and 76.6% for PLA. Infill percentage did not affect the dose at depths greater than 5 mm. Differences between measurements and TPS calculations were less than 4.1% for both materials, regardless of the infill percentage and depth. CONCLUSIONS: The use of 3D-printed light boluses increases the dose in the build-up region, which was shown based on the dosimetric measurements and TPS calculations.

Controlled formation of highly porous polylactic acid­calcium phosphate granules with defined structure.

Synthetic bone repair materials are becoming increasingly popular in tissue engineering as a replacement for autografts and human/animal-based bone grafts. The biomedical application requires precise control over the material composition and structure, as well as over the size of granulate used for filling the bone defects, as the pore size and interconnectivity affect the regeneration process. This paper proposes a process of alloplastic and biodegradable polylactic acid/ß-tricalcium phosphate granulates preparation and its parameters described. Using solvent-induced phase separation technique, porous spheres have been obtained in various sizes and morphologies. The design of the experiment's approach generated an experimental plan for further statistical modeling using the resulting data. The statistical modeling approach to the data from conducting a designed set of experiments allowed analysis of the influence of process parameters on the properties of the resulting granules. We confirmed that the content of ß-tricalcium phosphate plays the most significant role in the size distribution of prepared granulate. The shape of the particles becomes less spherical with higher phosphate concentration in the emulsion. The proposed technique allows preparing porous granulates in the 0.2-1.8 mm diameter range, where granules' mean diameter and sphericity are tunable with polymer and phosphate concentrations. The granulate created a potentially implantable scaffold for resected bone regeneration, as cytotoxicity tests assured the material is non-cytotoxic in vitro, and human mesenchymal stem cells have been cultured on the surface of granulates. Results from cell cultures seeded on the Resomer LR 706S granulates were the most promising.

Linking the Defective Structure of Boron-Doped Carbon Nano-Onions with Their Catalytic Properties: Experimental and Theoretical Studies.

Defects are widely present in nanomaterials, and they are recognized as the active sites that tune surface properties in the local region for catalysis. Recently, the theory linking defect structures and catalytic properties of nanocatalysts has been most commonly described. In this study, we prepared boron-doped carbon nano-onions (B-CNOs) by applying an annealing treatment of ultradispersed nanodiamond particles and amorphous boron. These experimental conditions guarantee doping of CNOs with boron atoms in the entire carbon nanostructure, thereby ensuring structural homogeneity. In our research, we discuss the correlations between defective structures of B-CNOs with their catalytic properties toward SO2 and tert-butanol dehydration. We show that there is a close relationship between the catalytic properties of the B-CNOs and the experimental conditions for their formation. It is not only the mass of the substrates used for the formation of B-CNOs that is crucial, that is, the mass ratio of NDs to amorphous B, but also the process, including temperature and gas atmosphere. As it was expected, all B-CNOs demonstrated significant catalytic activity in HSO3- oxidation. However, the subsequent annealing in an air atmosphere diminished their catalytic activity. Unfortunately, no direct relationship between the catalytic activity and the presence of heteroatoms on the B-CNO surface was observed. There was a linear dependence between catalytic activity and Raman reactivity factors for each of the B-CNO materials. In contrast to SO2 oxidation, the B-CNO-a samples showed higher catalytic activity in tert-butanol dehydration due to the presence of Brønsted and Lewis acid sites. The occurence of three types of boron-Lewis sites differing in electron donor properties was confirmed using quantitative infrared spectroscopic measurements of pyridine adsorption.

Insight into the Mechanisms of Low Coverage Adsorption of N-Alcohols on Single Walled Carbon Nanohorn.

We report for the first time the chromatographic study of n-alcohols (from methanol to butanol) adsorption on single walled carbon nanohorn (SWCNH). Using measured temperature dependence of adsorption isotherms (373-433 K) the isosteric adsorption enthalpy is calculated and compared with the data reported for a graphite surface. It is concluded that a graphite surface is more homogeneous, and the enthalpy of adsorption on SWCNHs at zero coverage correlates well with molecular diameter and polarizability, suggesting leading role of dispersive interactions, i.e., no heteroatoms presence in the walls of SWCNH structures. Next using modern DFT approach we calculate the energy of n-alcohols interactions with a graphene sheet and with a single nanocone finally proposing a more realistic-double nanocone model. Obtained results suggest alcohols entrapping between SWCNH with OH groups located toward nanocones ends, leading to the conclusions about very promising future applications of SWCNHs in catalytic reactions with participation of n-alcohols.

Revisiting Wetting, Freezing, and Evaporation Mechanisms of Water on Copper.

Wetting of metal surfaces plays an important role in fuel cells, corrosion science, and heat-transfer devices. It has been recently stipulated that Cu surface is hydrophobic. In order to address this issue we use high purity (1 1 1) Cu prepared without oxygen, and resistant to oxidation. Using the modern Fringe Projection Phase-Shifting method of surface roughness determination, together with a new cell allowing the vacuum and thermal desorption of samples, we define the relation between the copper surface roughness and water contact angle (WCA). Next by a simple extrapolation, we determine the WCA for the perfectly smooth copper surface (WCA = 34°). Additionally, the kinetics of airborne hydrocarbons adsorption on copper was measured. It is shown for the first time that the presence of surface hydrocarbons strongly affects not only WCA, but also water droplet evaporation and the temperature of water droplet freezing. The different behavior and features of the surfaces were observed once the atmosphere of the experiment was changed from argon to air. The evaporation results are well described by the theoretical framework proposed by Semenov, and the freezing process by the dynamic growth angle model.

The Finite Pore Volume GAB Adsorption Isotherm Model as a Simple Tool to Estimate a Diameter of Cylindrical Nanopores.

The finite pore volume Guggenheim-Anderson-de Boer (fpv-GAB) adsorption isotherm model has been considered as a simple tool which not only enables us to analyze the shape of isotherms theoretically, but also provides information about pore diameter. The proposed methodology is based on the geometrical considerations and the division of the adsorption space into two parts: the monolayer and the multilayer space. The ratio of the volumes of these two spaces is unambiguously related to the pore diameter. This ratio can be simply determined from the N2 adsorption isotherm by its fitting with the use of fpv-GAB model. The volume ratio is equal to the ratio of the adsorption capacities in the monolayer and the multilayer-two of the best-fit parameters. The suggested approach has been verified using a series of isotherms simulated inside ideal carbon nanotubes. The adsorption data for some real adsorbents has also been used during tests. The studies performed have proven that diameters estimated with the use of the proposed method are comparable with the geometrical sizes or diameters published by others and based on the application of more sophisticated methods. For pores wider than 3 nm, the relative error does not exceed a few percent. The approach based on the fpv-GAB model reflects well the differences in pore sizes for the series of materials. Therefore, it can be treated as a convenient tool to compare various samples.

Chitosan-Human Bone Composite Granulates for Guided Bone Regeneration.

The search for the perfect bone graft material is an important topic in material science and medicine. Despite human bone being the ideal material, due to its composition, morphology, and familiarity with cells, autografts are widely considered demanding and cause additional stress to the patient because of bone harvesting. However, human bone from tissue banks can be used to prepare materials in eligible form for transplantation. Without proteins and fats, the bone becomes a non-immunogenic matrix for human cells to repopulate in the place of implantation. To repair bone losses, the granulate form of the material is easy to apply and forms an interconnected porous structure. A granulate composed of ß-tricalcium phosphate, pulverized human bone, and chitosan-a potent biopolymer applied in tissue engineering, regenerative medicine, and biotechnology-has been developed. A commercial encapsulator was used to obtain granulate, using chitosan gelation upon pH increase. The granulate has been proven in vitro to be non-cytotoxic, suitable for MG63 cell growth on its surface, and increasing alkaline phosphatase activity, an important biological marker of bone tissue growth. Moreover, the granulate is suitable for thermal sterilization without losing its form-increasing its convenience for application in surgery for guided bone regeneration in case of minor or non-load bearing voids in bone tissue.

Discovery of a series of ester-substituted NLRP3 inflammasome inhibitors.

The NLRP3 inflammasome is a component of the innate immune system involved in the production of proinflammatory cytokines. Aberrant activation by a wide range of exogenous and endogenous signals can lead to chronic, low-grade inflammation. It has attracted a great deal of interest as a drug target due to the association with diseases of large unmet medical need such as Alzheimer's disease, Parkinson's disease, arthritis, and cancer. To date, no drugs specifically targeting inhibition of the NLRP3 inflammasome have been approved. In this work, we used the known NLRP3 inflammasome inhibitor CP-456,773 (aka CRID3 or MCC 950) as our starting point and undertook a Structure-Activity Relationship (SAR) analysis and subsequent scaffold-hopping exercise. This resulted in the rational design of a series of novel ester-substituted urea compounds that are highly potent and selective NLRP3 inflammasome inhibitors, as exemplified by compounds 44 and 45. It is hypothesized that the ester moiety acts as a highly permeable delivery vehicle and is subsequently hydrolyzed to the carboxylic acid active species by carboxylesterase enzymes. These molecules are greatly differentiated from the state-of-the-art and offer potential in the treatment of NLRP3-driven diseases, particularly where tissue penetration is required.

Effect of Maternal Diet and Medium Chain Fatty Acids Supplementation for Piglets on Their Digestive Tract Development, Structure, and Chyme Acidity as Well as Performance and Health Status.

The objective of the present study was to evaluate the effect of oils for sows during late pregnancy and lactation on offspring performance. In addition, the effect of caprylic acid (C8) or medium-chain triglyceride oil (MCT) in piglets' feed on their gut development, performance, and health status was determined. The experiment was conducted on 24 sows allocated to two treatments: diet with rapeseed oil or with coconut oil. Newborn piglets were randomly allocated to three treatments: feed with no supplement or supplemented with 0.3% MCT or with 0.3% C8. The results showed that both oils had no effect on sow reproductive rates; however, fatty acid patterns of milk differed significantly and the number of lost piglets was lower in sow fed with coconut oil. Both caprylic and MCT oil significantly improved piglet performance and villus height. These additives did not change triacylglycerol content in blood, but C8 lowered total cholesterol and MCT increased IgG content. It can be concluded that coconut oil fed to pregnant and lactating sows can markedly reduce the mortality of piglets and that caprylic acid and medium-chain fatty acid oil can be a good supplement in weaned piglet feed.

Patient specific implants for jawbone reconstruction after tumor resection.

In case of benign and malignant tumours affecting the maxillofacial region, the resection of jawbone reflects the standard therapy in more than 5.000 cases per year within the European Union. The resulting large bone defects lead to scarred, mangled facial appearance, loss of mastication and probably speech, requiring aesthetic and functional surgery as a basis for physical and physiological rehabilitation. Although autologous vascularized bone autografts reflect the current golden standard, the portion of bone available for the procedure is limited and subsequent high-dose anti-cancer chemo-/radiotherapy can lead to local tissue necrosis. Autologous vascularized bone from fibular or iliac-crest autografts is current golden standard in jawbone resection post-treatment, however, the portion of transplantable bone is limited and subsequent high-dose anti-cancer chemo-/radiotherapy often results in tissue necrosis Our research focuses on alternative treatment techniques: tissue reconstruction via novel patient-specifically manufactured maxillofacial implant that stimulates bone tissue growth. The planned neoformation of vascularized bone in such implants within the patient's own body as "bioreactor" is the safest approach in tissue engineering. The works described herein included the design of the metallic substrate of the implant with the use of computed tomography basing on real patients scans and then 3D-printing the substrates from the Ti6Al7Nb powder. The metal core was then evaluated in terms of structural characteristic, cytotoxicity and gene expression through the in vitro tests. Further experiments were focused on fabrication of the biocompatible coating for outer surface of the bone implant that would enhance the healing process and accelerate the tissue growth. Functional polymeric granulate dedicated for osteoconductive, osteoinductive and osteogenesis properties were elaborated. Another approach including the coating for the implant surface with two-phase biocompatible layer including polymeric microspheres and hydrogel carrier, which would provide long-time release of bone and cartilage growth factors around the implant were also done. The polymeric granulate containing ßTCP improved bone cells growth, but it some modification has to be done in order to improve structural pores to ensure for better osteoconductivity. The biocompatible coating including PVP hydrogel and polymeric microspheres is still in the development process.

What Is the Value of Water Contact Angle on Silicon?

Silicon is a widely applied material and the wetting of silicon surface is an important phenomenon. However, contradictions in the literature appear considering the value of the water contact angle (WCA). The purpose of this study is to present a holistic experimental and theoretical approach to the WCA determination. To do this, we checked the chemical composition of the silicon (1,0,0) surface by using the X-ray photoelectron spectroscopy (XPS) method, and next this surface was purified using different cleaning methods. As it was proved that airborne hydrocarbons change a solid wetting properties the WCA values were measured in hydrocarbons atmosphere. Next, molecular dynamics (MD) simulations were performed to determine the mechanism of wetting in this atmosphere and to propose the force field parameters for silica wetting simulation. It is concluded that the best method of surface cleaning is the solvent-reinforced de Gennes method, and the WCA value of silicon covered by SiO2 layer is equal to 20.7° (at room temperature). MD simulation results show that the mechanism of pure silicon wetting is similar to that reported for graphene, and the mechanism of silicon covered by SiO2 layer wetting is similar to this observed recently for a MOF.

Multiscale design of artificial bones with biomimetic elastic microstructures.

Cancellous bone is a highly porous, heterogeneous, and anisotropic material which can be found at the epiphyses of long bones and in the vertebral bodies. The hierarchical architecture makes cancellous bone a prime example of a lightweight natural material that combines strength with toughness. Better understanding the mechanics of cancellous bone is of interest for the diagnosis of bone diseases, the evaluation of the risk of fracture, and for the design of artificial bones and bone scaffolds for tissue engineering. A multiscale optimization method to maximize the stiffness of artificial bones using biomimetic cellular microstructures described by a finite set of geometrical micro-parameters is presented here. The most outstanding characteristics of its implementation are the use of: an interior point optimization algorithm, a precalculated response surface methodology for the evaluation of the elastic tensor of the microstructure as an analytical function of the micro-parameters, and the adjoint method for the computation of the sensitivity of the macroscopic mechanical response to the variation of the micro-parameters. The performance and effectiveness of the tool are evaluated by solving a problem that consists in finding the optimal distribution of the microstructures for a proximal end of a femur subjected to physiological loads. Two strategies for the specification of the solid volume fraction constraints are assessed. The results are compared with data of a computed tomography study of an actual human bone. The model successfully predicts the main features of the spatial arrangement of the trabecular and cortical microstructures of the natural bone.

Serine Biosynthesis Pathway Supports MYC-miR-494-EZH2 Feed-Forward Circuit Necessary to Maintain Metabolic and Epigenetic Reprogramming of Burkitt Lymphoma Cells.

Burkitt lymphoma (BL) is a rapidly growing tumor, characterized by high anabolic requirements. The MYC oncogene plays a central role in the pathogenesis of this malignancy, controlling genes involved in apoptosis, proliferation, and cellular metabolism. Serine biosynthesis pathway (SBP) couples glycolysis to folate and methionine cycles, supporting biosynthesis of certain amino acids, nucleotides, glutathione, and a methyl group donor, S-adenosylmethionine (SAM). We report that BLs overexpress SBP enzymes, phosphoglycerate dehydrogenase (PHGDH) and phosphoserine aminotransferase 1 (PSAT1). Both genes are controlled by the MYC-dependent ATF4 transcription factor. Genetic ablation of PHGDH/PSAT1 or chemical PHGDH inhibition with NCT-503 decreased BL cell lines proliferation and clonogenicity. NCT-503 reduced glutathione level, increased reactive oxygen species abundance, and induced apoptosis. Consistent with the role of SAM as a methyl donor, NCT-503 decreased DNA and histone methylation, and led to the re-expression of ID4, KLF4, CDKN2B and TXNIP tumor suppressors. High H3K27me3 level is known to repress the MYC negative regulator miR-494. NCT-503 decreased H3K27me3 abundance, increased the miR-494 level, and reduced the expression of MYC and MYC-dependent histone methyltransferase, EZH2. Surprisingly, chemical/genetic disruption of SBP did not delay BL and breast cancer xenografts growth, suggesting the existence of mechanisms compensating the PHGDH/PSAT1 absence in vivo.

Electrophoretic Deposition of Layer-by-Layer Unsheathed Carbon Nanotubes-A Step Towards Steerable Surface Roughness and Wettability.

It is well known that carbon nanotube (CNT) oxidation (usually with concentrated HNO3) is a major step before the electrophoretic deposition (EPD). However, the recent discovery of the "onion effect" proves that multiwalled carbon nanotubes are not only oxidized, but a simultaneous unsheathing process occurs. We present the first report concerning the influence of unsheathing on the properties of the thus-formed CNT surface layer. In our study we examine how the process of gradual oxidation/unsheathing of a series of multiwalled carbon nanotubes (MWCNTs) influences the morphology of the surface formed via EPD. Taking a series of well-characterized and gradually oxidized/unsheathing Nanocyl MWCNTs and performing EPD on a carbon fiber surface, we analyzed the morphology and wettability of the CNT surfaces. Our results show that the water contact angle could be gradually changed in a wide range (125-163°) and the major property determining its value was the diameter of aggregates formed before the deposition process in the solvent. Based on the obtained results we determined the parameters having a crucial influence on the morphology of created layers. Our results shed new light on the deposition mechanism and enable the preparation of surfaces with steerable roughness and wettability.

Opening the internal structure for transport of ions: improvement of the structural and chemical properties of single-walled carbon nanohorns for supercapacitor electrodes.

We investigated the electrochemical performance of single-walled carbon nanohorns (SWCNHs) for use as supercapacitor electrodes. For the first time, we used acid-treatment for oxidation of SWCNHs and hole creation in their structure. A detailed study was performed on the correlation between the oxidation of SWCNHs via acid treatment and variable acid treatment times, the structural properties of the oxidized carbon nanostructures, and the specific capacitance of the SWCNH electrodes. We showed that simple functionalization of carbon nanostructures under controlled conditions leads to an almost 3-fold increase in their specific capacitance (from 65 to 180 F g-1 in 0.1 M H2SO4). This phenomenon indicates higher accessibility of the surface area of the electrodes by electrolyte ions as a result of gradual opening of the SWCNH internal channels.