Ita Junkar

• PhD
• Research Associate at Jožef Stefan Institute

Stainless-steel grade 316L is widely used in medical and food processing applications due to its corrosion resistance and durability. However, its inherent lack of antibacterial properties poses a challenge in environments requiring high hygiene standards. This study investigates a novel surface modification approach combining electrochemical anodi...

Biosensors are pivotal in biomedical applications, particularly for disease detection, diag-nosis, treatment, health management, and monitoring. Titanium dioxide (TiO2) is a prom-inent material for biosensors due to its biocompatibility, corrosion resistance, and availa-bility in various nanostructured forms. This study explores the interaction of...

The present study introduces an advanced surface modification approach combining electrochemical anodization and non-thermal plasma treatment, tailored for biomedical applications on stainless steel grade 316L (SS316L) surfaces. Nanopores with various diameters (100–300 nm) were synthesized with electrochemical anodization, and samples were further...

Plasma technology is a rapidly growing field of science that permeates various branches of medicine and dental medicine. In dental medicine, cold or nonthermal gaseous plasma can be used directly in the oral cavity for the surface treatment of hard dental tissues, periodontal tissues, or oral mucosa or indirectly for treating dental ma-terials befo...

Cardiovascular diseases are a pre-eminent global cause of mortality in the modern world. Typically, surgical intervention with implantable medical devices such as cardiovascular stents is deployed to reinstate unobstructed blood flow. Unfortunately, existing stent materials frequently induce restenosis and thrombosis, necessitating the development...

Cold plasma (CP) has a great potential for decontamination or improvement of grain germination. However, disputing results have been reported, as plasma treatment can affect species and varieties of grains in different ways. The differences may be due to the chemical composition of grain pericarps, the structure of the grains and metabolic response...

Increasing the concentration of an element in edible produce (i.e., biofortification) can mitigate the element deficiency in humans. Sprouts are small but popular part of healthy diets providing vitamins and essential elements throughout the year. Element composition of sprouts can easily be amended, e.g., by soaking the grains in element-rich solu...

Implant-associated infections (IAI) are a common cause for implant failure, increased medical costs, and critical for patient healthcare. Infections are a result of bacterial colonization, which leads to biofilm formation on the implant surface. Nanostructured surfaces have been shown to have the potential to inhibit bacterial adhesion mainly due t...

In our study, plasma surface modification was employed to tailor the surface properties of magnesium in terms of surface chemistry, topography, and wettability. For two sets of samples, the plasma treatment involved two steps using two different gases (hydrogen and oxygen), while one set of samples was treated with one step only using oxygen. X-ray...

Despite the inadequate biocompatibility, medical-grade stainless steel materials have been used as body implants for decades. The desired biological response of surfaces to specific applications in the body is a highly challenging task, and usually not all the requirements of a biomaterial can be achieved. In recent years, nanostructured surfaces h...

Cold plasma (CP) technology is a technique used to change chemical and morphological characteristics of the surface of various materials. It is a newly emerging technology in agriculture used for seed treatment with the potential of improving seed germination and yield of crops. Wheat seeds were treated with glow (direct) or afterglow (indirect) lo...

In the present roadmap, recent advances in antibacterial properties of nanostructured surfaces on metal substrates used in medical applications are presented. The importance of antibacterial surfaces for their application in medicine is described and the most commonly applied synthesis methods for fabrication of nanostructured antibacterial surface...

Nanoporous ceramic coatings such as titania are promoted to produce drug-free cardiovascular stents with a low risk of in-stent restenosis (ISR) because of their selectivity towards vascular cell proliferation. The brittle coatings applied on stents are prone to cracking because they are subjected to plastic deformation during implantation. This st...

The research presented herein follows an urgent global need for the development of novel surface engineering techniques that would allow the fabrication of next-generation cardiovascular stents, which would drastically reduce cardiovascular diseases (CVD). The combination of hydrothermal treatment (HT) and treatment with highly reactive oxygen plas...

Cold plasma technology has received significant attention in agriculture due to its effect on the seeds and plants of important cultivars, such as wheat. Due to climate change, wherein increasing temperatures and droughts are frequent, it is important to consider novel approaches to agricultural production. As increased dormancy levels in wheat are...

In this review paper, we theoretically explain the origin of electrostatic interactions between lipid bilayers and charged solid surfaces using a statistical mechanics approach, where the orientational degree of freedom of lipid head groups and the orientational ordering of the water dipoles are considered. Within the modified Langevin Poisson–Bolt...

Cellulose is a promising biomass material suitable for high volume applications. Its potential lies in sustainability, which is becoming one of the leading trends in industry. However, there are certain drawbacks of cellulose materials which limit their use, especially their high wettability and low barrier properties, which can be overcome by appl...

In this paper, a review of cold plasma setups and the physical and chemical processes leading to the generation of active species is presented. The emphasis is given to the interaction of cold plasmas with materials used in medical applications, especially medical implants as well as live cells. An overview of the different kinds of plasmas and tec...

Bacterial infections of medical devices present severe problems connected with long-term antibiotic treatment, implant failure, and high hospital costs. Therefore, there are enormous demands for innovative techniques which would improve the surface properties of implantable materials. Plasma technologies present one of the compelling ways to improv...

Highly ordered and uniform titanium dioxide (TiO2) nanotubes (NTs) with different morphologies (15 nm, 50 nm and 100 nm in diameter) were prepared by the electrochemical anodization of Ti substrates. The TiO2 NTs’ surface properties were characterized by X-ray diffraction (XRD) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM) an...

The active role of biomaterials in the regeneration of tissues and their ability to modulate the behavior of stem cells in terms of their differentiation is highly advantageous. Here, polypyrrole, as a representantive of electro-conducting materials, is found to modulate the behavior of embryonic stem cells. Concretely, the aqueous extracts of poly...

Nonthermal plasma (NTP), or cold plasma, has shown many advantages in the agriculture sector as it enables removal of pesticides and contaminants from the seed surface, increases shelf life of crops, improves germination and resistance to abiotic stress. Recent studies show that plasma treatment indeed offers unique and environmentally friendly pro...

Seeds have large economic importance all over the world. They are an essential source of minerals, proteins, starch, and oil reserves in the early stages of plant development and growth. A high abundance of such molecules makes seeds of cereals and legumes a major food source for the majority of the human world population. However, to gain optimal...

Seeds can be considered as natural biopolymers. [...]

Novel Extracellular Vesicles (EVs) based diagnostic techniques are promising non-invasive procedures for early stage disease detection which are gaining importance in the medical field. EVs are cell derived particles found in body liquids, especially blood, from which they are isolated for further analysis. However, techniques for their isolation a...

Three different types of paper with different coatings have been used in order to study the influence of gaseous plasma treatment on surface properties of paper. Radio frequency (RF) oxygen plasma was used for treatment of papers that contain different parts of organic and inorganic components in their coatings. Surface properties like surface morp...

In this review, strategies for improving the antimicrobial properties of stainless steel (SS) are presented. The main focus given is to present current strategies for surface modification of SS, which alter surface characteristics in terms of surface chemistry, topography and wettability/surface charge, without influencing the bulk attributes of th...

Crystallization alters the characteristics of TiO2 nanosurfaces, which consequently influences their bio-performance. In various biomedical applications, the anatase or rutile crystal phase is preferred over amorphous TiO2. The most common crystallization technique is annealing in a conventional furnace. Methods such as hydrothermal or room tempera...

An extremely asymmetric low-pressure discharge was used to study the composition of thin films prepared by PECVD using HMDSO as a precursor. The metallic chamber was grounded, while the powered electrode was connected to an RF generator. The ratio between the surface area of the powered and grounded electrode was about 0.03. Plasma and thin films w...

Efficient stent implantation among others depends on avoiding the aggregation of platelets in the blood vessels and appropriate proliferation of endothelial cells and controlled proliferation of smooth muscle cells, which reduces the development of pathology, such as neointimal hyperplasia, thrombosis, and restenosis. The current article provides a...

Hemocompatibility is an essential prerequisite for the application of materials in the field of biomedicine and biosensing. In addition, mixed ionic and electronic conductivity of conducting polymers is an advantageous property for these applications. Heparin-like materials containing sulfate, sulfamic, and carboxylic groups may have an anticoagula...

Depending on the climate, garlic can be planted either in the fall or spring for a harvest in the summer, but spring planting might require the strengthening of the plant by external techniques. We have used low pressure, inductively coupled, radio frequency oxygen plasma for the treatment of peeled garlic cloves of a spring-planted Slovenian autoc...

Extracellular vesicles (EVs) isolated from biological samples are a promising material for use in medicine and technology. However, the assessment methods that would yield repeatable concentrations, sizes and compositions of the harvested material are missing. A plausible model for the description of EV isolates has not been developed. Furthermore,...

The nanotexturing of microstructured polystyrene surfaces through CF4 plasma chemical fluorination is presented in this study. It is demonstrated that the parameters of a surface micropore-generation process, together with the setup of subsequent plasma-chemical modifications, allows for the creation of a long-term (weeks) surface-stable micro- and...

Facile crystallization of titanium oxide (TiO2) nanotubes (NTs), synthesized by electrochemical anodization, with low pressure non-thermal oxygen plasma is reported. The influence of plasma processing conditions on TiO2 NTs crystal structure and morphology was examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). For the first...

We summarize recent findings and advances in cancer diagnostics in relation to extracellular vesicles (EVs) and emerging therapeutic options of nanomaterials. We revise the common mechanism for EV inception, vesiculation, through a physical model of the liquid mosaic membrane with laterally mobile membrane rafts that determine local spontaneous cur...

The photocatalytic activity of TiO2 nanotubes (NTs) makes these materials promising candidates for a variety of applications, including photocatalytic degradation, water splitting and biomedical devices. The large band gap of TiO2 m(anatase 3.2 eV; rutile 3.0 eV)requires excitation with UV light, which accounts for only a small fraction of solar li...

Conducting polymers (CP), namely polyaniline (PANI) and polypyrrole (PPy), are promising materials applicable for the use as biointerfaces as they intrinsically combine electronic and ionic conductivity. Although a number of works have employed PANI or PPy in the preparation of copolymers, composites, and blends with other polymers, there is no sys...

In the present study we demonstrated that composite PPHMDS/DND coatings with elastic moduli close to those of mature bone tissue (0.2–2.8 GPa) stimulated growth and osteogenic differentiation of human adipose-derived mesenchymal stem cells (hADMSCs). Composite coatings were prepared by a method of plasma polymerization (PP) where detonation nanodia...

Functionality of polymeric coating, especially in terms of anti-corrosive properties and stability, can be negatively influenced by formation of either bacterial or fungal biofilm on its surface. Herein, the epoxy-ester resin based polymeric coating was filled with pigments (natural silicon dioxide diatomite, natural wollastonite, tungstate and mol...

Regardless of the high awareness of the importance of early cancer diagnosis, a high mortality rate is still present due to cancer discovery at a high advancement of the disease, where it has already metastasized. One of the fields where improvement is needed are the current diagnostic methods that cannot discern the cancerous lesions when these ar...

Infections by pathogenic microorganisms present a serious concern in health care sector, as such infections kill more people than any other cause. The bacterial infections are commonly treated by antibiotics, but serious problems occur because of biofilm formation, which highly reduce the effectiveness of antibiotic therapy. Moreover, the overuse o...

Conducting polyaniline can be prepared and modified using several procedures, all of which can significantly influence its applicability in different fields of biomedicine or biotechnology. The modifications of surface properties are crucial with respect to the possible applications of this polymer in tissue engineering or as biosensors. Innovative...

The as-synthesized TiO2 nanorods a-TNR (amorphous TiO2 layer covering the crystalline anatase TiO2 core) and TNR (fully crystalline anatase TiO2) were decorated with reduced graphene oxide (rGO) to synthesize two series of TiO2+rGO composites with different nominal loadings of GO (from 4 to 20 wt. %). Structural, surface and electronic properties o...

Nanostructured TiO2 nanotubes (NTs) of diameters from 15 to 100 nm were fabricated by an electrochemical anodization process. Biofilm-positive strains of Bacillus cereus and Pseudomonas aeruginosa behaved similarly on all TiO2 NTs as well as on native titanium (Ti) foil. The adhesion and growth of mesenchymal stem cells (MSc), embryonic stem cells...

Nanoscale topography on various titanium surfaces has already been shown to improve vascular response in vitro. To propose a novel strategy for translation into clinically used vascular implants, it is imperative that the surface should also be properly conditioned to provide a better environment for adhesion and proliferation of cells. Electrochem...

Interaction of cells and platelets with biomaterials is very complex and still not fully understood. Yet, we already know that the surface of a biomaterial is responsible for initiating the primary response to body fluids, so it is of vital importance to ensure that it is suitably conditioned to provide a desired biological response (biocompatibili...

Optimization of polymer surface functionalities can control the biological processes such as cell adhesion, proliferation, viability and enhanced extracellular matrix (ECM) secretion functions at biointerfaces. Two main strategies in surface modification of polymeric materials are often applied. Firstly, the material surface properties such as chem...

The aim of this study was to develop the potential tissue engineering applications of d-glucosamine (GlcN) immobilized onto the surface of a biodegradable matrix in order to induce a desired biological effect at biointerfaces. Thus, for sample preparation we used a novel multistep physicochemical approach. In the first step the poly(lactic acid) (P...

Surface charge is one of the most significant properties for the characterisation of a biomaterial, being a key parameter in the interaction of the body implant with the surrounding living tissues. The present study concerns the systematic assessment of the surface charge of electrochemically anodized TiO 2 nanotubular surfaces, proposed as coating...

In the present study the biological response to various nanotopographic features after gaseous plasma treatment were studied. The usefulness of nanostructured surfaces for implantable materials has already been acknowledged, while less is known on the combined effect of nanostructured plasma modified surfaces. In the present work the influence of o...

Surface topography and physicochemical properties such as adhesion, cohesion and wettability is presumed to alter/facilitate the protein binding, cell adhesion and proliferation, thereby reducing post-operative complications with increased lifespan of biomedical implants.1 Current study examines the ageing behaviour of titanium dioxide (TiO2) nanot...

H2S plasma created by an electrode-less radio-frequency discharge was used to modify the surface properties of the polymer polyethylene terephthalate. X-ray photoelectron spectroscopy, secondary ion mass spectrometry and atomic force microscopy were used to determine the evolution of the surface functionalities and morphology. A very thin film of c...

Sterilization is the final surface treatment procedure of all implantable devices and is one of the key factors which have to be considered before implementation. Since different sterilization procedures for all implantable devices influence mechanical properties as well as biological response, the influence of different sterilization techniques on...

The development of lignocellulosic natural fibre reinforced polymers composites are constrained by two limitations: the upper temperature at which the fibre can be processed and the significant differences between the surface energy of the fibre and the polymer matrix. Since the fibres and matrices are chemically different, strong adhesion at their...

Nanoscale topography in improving vascular response in vitro was established previously on various titanium surfaces. In the present study different surface nanotopographies i.e. different diameters of titanium dioxide (TiO2 ) nanotubes were fabricated by electrochemical anodization and conditioned with highly reactive gaseous oxygen plasma. The mo...

High growth and yield of food crops are desired due to globally increased food demands. Highly reactive gaseous plasma treatment technologies have been recently shown to improve the growth of various types of seeds, and we attempted to study the influence of different treatment conditions on the growth of garlic cloves. Inductively coupled, low-pre...

The applications of zinc oxide (ZnO) nanowires (NWs) in implantable wireless devices, such as diagnostic nanobiosensors and nanobiogenerators, have recently attracted enormous attention due to their unique properties. However, for these implantable nanodevices, the biocompatibility and the ability to control the behaviour of cells in contact with Z...

Objectives: Peri-implantitis and peri-mucositis pose a severe threat to the success of dental implants. Current research focuses on the development of surfaces that inhibit biofilm formation while not inferring with tissue integration. This study compared the adherence of two oral bacterial species, Streptococcus sanguinis and Streptococcus mutans...

A critical factor in reinforced polymer is the strength of the bond between the fibre and polymer matrix, becuase the load is transmitted through the fibre matrix interface. The quality of fibre matrix interface is significant for the application of natural fibre as reinforcement for polymers [1,2].The present study focuses on the surface propertie...

Atmospheric pressure plasma jet was employed to improve adhesion between polypropylene (PP) column wall and monolith used in chromatography. Different treatment conditions for modification of PP tube were used and the effects of treatment were analysed with X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Modified surfaces...

Polyaniline is a promising conducting polymer with still increasing application potential in biomedicine. Its surface modification can be an efficient way how to introduce desired functional groups and to control its properties while keeping the bulk characteristics of the material unchanged. The purpose of the study was to synthetize thin films of...

A commercial formulation of styrene-acrylonitrile copolymer (SAN) sheets were surface-modified by using non-thermal radiofrequency and microwave plasma treatments. In order to evaluate the possible improvement of SAN surface properties, the modification was performed using oxygen and tetraflouromethane (CF4) discharges under different treatment dur...

Some applications of extremely non-equilibrium oxygen plasma for tailoring the surface properties of organic as well as inorganic materials are presented. Plasma of low or moderate ionization fraction and very high dissociation fraction is created by high frequency electrodeless discharges created in chambers made from a material of low recombinati...

Polyethylene terephthalate (PET) foils have been exposed to oxygen plasma and its afterglow in order to reveal compositional and structural modifications of the surface layer. Oxygen plasma was created by electrodeless RF discharge in a glass chamber so the O-atom density was close to 10(22) m(-3) although the density of charged particles was only...

Improved hemocompatibility from the perspective of platelets adhesion and activation on polyethylene terephthalate surfaces has been addressed. The activation stage of platelets has been determined from their size and morphology using scanning electron microscopy (SEM). The activation of platelets on untreated polymer materials was very intensive....

Improvement in hemocompatibility of highly oriented pyrolytic graphite (HOPG) by formation of nanostructured surface by oxygen plasma treatment is reported. We have showed that by appropriate fine tuning of plasma and discharge parameters we are able to create nanostructured surface which is densely covered with nanocones. The size of the nanocones...

Collagen thin films were prepared via bovine atelocollagen matrices. The film casting was carried out by using different culture dishes, concentrations, equipment, drying processes and periods of time. In order to optimise the repeatability and reproducibility, microscopic analyses were utilised to explore the film quality and topographical pattern...

Collagen thin films were prepared via bovine atelocollagen matrices. The film casting was carried out by using different culture dishes, concentrations, equipment, drying processes and periods of time. In order to optimise the repeatability and reproducibility, microscopic analyses were utilised to explore the film quality and topographical pattern...

Polyethylene (PE) is one of the most widely used polymers in many industrial applications. Biomedical uses seem to be attractive, with increasing interest. However, PE it prone to infections and its additional surface treatment is indispensable. An increase in resistance to infections can be achieved by treating PE surfaces with substances containi...

Improving hemocompatibility of blood connecting devices is one of the key issues in biomaterial science. To prevent and study the effects of platelet adhesion and activation on polyethylene terephthalate (PET), a highly non-equilibrium oxygen plasma was used. Surface analyzing techniques confirmed that incorporation of oxygen functional groups, ach...

Low-density polyethylene (LDPE) belongs to commodity polymer materials applied in biomedical applications due to its favorable mechanical and chemical properties. The main disadvantage of LDPE in biomedical applications is low resistance to bacterial infections. An antibacterial modification of LDPE appears to be a solution to this problem. In this...

Thrombosis and restenosis are the most common problems during insertion of biocompatible implants like titanium stents into human blood, due to aggregation of platelets on their surfaces. Because of this reason, we studied the response of blood platelets to a plasma treated titanium surface. The aim was to design a functionalized surface which woul...

Three monomers (allylamine, N-allylmethylamine and N,N-dimethylallylamine) were used for grafting onto air plasma activated LDPE surface. Antibacterial agent triclosan was anchored on such substrates. Influence of graft type on the antibacterial properties was determined. Increase of antibacterial activity and amount of deposited antibacterial agen...

Conformal films of fluoropolymer have been made onto carbonyl iron microparticles by plasma-enhanced chemical vapour deposition of octafluorocyclobutane in this study. RF plasma reactor with a frequency of 40 kHz and rotating barrel fixed between the two discharge electrodes arrangement was used to achieve a uniform surface modification of particle...

Polyethylene (PE) is one of the most widely used polymers in many industrial applications. Biomedical uses seem to be attractive, with increasing interest. However, PE it prone to infections and its additional surface treatment is indispensable. An increase in resistance to infections can be achieved by treating PE surfaces with substances containi...