Papers by Agnieszka Wiącek
International journal of molecular sciences, May 29, 2024
International journal of molecular sciences, Jan 29, 2024
Langmuir, 2008
Zeta potentials and effective diameters of n-tetradecane emulsions in 1 M ethanol were investigat... more Zeta potentials and effective diameters of n-tetradecane emulsions in 1 M ethanol were investigated in the presence of 1,2-dipalmitoyl- sn-glycero-3-phosphocholine (DPPC) (1 mg/100 mL), Candida cylindracea lipase (CCL), and phospholipase PLA2 (1 mg/100 mL) at 20, 37, and 45 degrees C. The enzyme was added at the beginning of mechanical emulsion homogenization or 1 min before the end of stirring for 10 min at 10,000 rpm. It was found that DPPC decreases the negative zeta potentials at all three temperatures. The decrease was largest at 20 degrees C and smallest at 45 degrees C. The influence of the enzymes on the zeta potentials depended on the enzyme kind, time of its injection, and temperature. More negative values of the zeta potentials relative to n-C14H30/DPPC droplets were obtained if the lipase was present. Generally, the effective diameters correlate with the zeta potentials, i.e., lower zeta potential corresponds with bigger effective diameter. Possible reasons for the observed changes of the measured parameters are discussed.
Pharmaceutics, Dec 15, 2022
Molecules
Polyetheretherketone (PEEK) is a biocompatible, chemically and physically stable radiolucent poly... more Polyetheretherketone (PEEK) is a biocompatible, chemically and physically stable radiolucent polymer that exhibits a similar elastic modulus to the normal human bone, making it an attractive orthopedic implant material. However, PEEK is biologically inert, preventing strong enough bonding with the surrounding bone tissue when implanted in vivo. Surface modification and composite preparation are the two main strategies for the improvement of the bioactivity of PEEK. In this study, the plasma activated PEEK surfaces with the embedded bioglass, chitosan, and bioglass-chitosan mixed layers applying from the solution dip-coating technique were investigated. The most prominent factors affecting the coating biocompatibility are strictly connected with the composition of its outer surface (its charge and functional groups), hydrophilic-hydrophobic character, wettability and surface free energy, and topography (size of pores/substructures, roughness, stiffness), as well as the personal chara...
Molecules, 2022
The aim of the study was to determine the bactericidal properties of popular medical, pharmaceuti... more The aim of the study was to determine the bactericidal properties of popular medical, pharmaceutical, and cosmetic ingredients, namely chitosan (Ch), hyaluronic acid (HA), and titanium dioxide (TiO2). The characteristics presented in this paper are based on the Langmuir monolayer studies of the model biological membranes formed on subphases with these compounds or their mixtures. To prepare the Langmuir film, 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DPPG) phospholipid, which is the component of most bacterial membranes, as well as biological material-lipids isolated from bacteria Escherichia coli and Staphylococcus aureus were used. The analysis of the surface pressure-mean molecular area (π-A) isotherms, compression modulus as a function of surface pressure, CS−1 = f(π), relative surface pressure as a function of time, π/π0 = f(t), hysteresis loops, as well as structure visualized using a Brewster angle microscope (BAM) shows clearly that Ch, HA, and TiO2 have antibac...
Chemical Engineering Journal, 2018
Annales UMCS, Chemia, 2015
This review paper focused on the effect of typical phosphorlipid (or lecithin) and enzyme modific... more This review paper focused on the effect of typical phosphorlipid (or lecithin) and enzyme modification on electrokinetic parameters of oil/water emulsion. Physicochemical properties of the systems were investigated taking into account the effective diameter of the droplets as well as the zeta potentials using the dynamic light scattering technique. The effect of phospholipid and phospholipase modification on interfacial properties of o/w emulsion was examined as a function of temperature, pH and ionic strength (effect of NaThe phospholipids dipalmitoylphosphatidylcholine, DPPC or dioleoylphosphatidylcholine, DOPC having the same headgroup bound to the apolar tail composed of two saturated or unsaturated chains were used as stabilizing agents. The effective diameters do not always correlate with the zeta potentials. A possible reason for such behaviour might a mechanism different from the electrostatic stabilization. Phospholipids and their mixtures (e.g. lecithin) may undergo sponta...
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 1997
Progress on Chemistry and Application of Chitin and its Derivatives, 2021
The wetting properties of chitosan (Ch) and single 1,2-dipalmitoylsn-glycero-3-phosphocholine (DP... more The wetting properties of chitosan (Ch) and single 1,2-dipalmitoylsn-glycero-3-phosphocholine (DPPC), cholesterol (Chol) and binary DPPC-Chol layers deposited onto polyethylene terephthalate activated by low-temperature air plasma (PETair) were examined. PET is widely used in tissue engineering, but its low hydrophilicity limits its integration with the surrounding tissues. Ch is a biocompatible polysaccharide, distinguished by its antimicrobial properties, widely distributed in medicine. DPPC and Chol are the major building components of cell membrane, so they can perfectly mimic membrane behaviour during contact with the Ch layer. Monolayers of lipids were deposited onto PETair with or without the Ch layer using the Langmuir-Blodgett technique. The total surface free energy (SFE)and its components changes were calculated from theoretical approaches. Wettability strongly depended on the monolayer composition as well as the Ch layer. The Ch film decreased the contact angle and incre...
Titanium dioxide has been studied for many years as a model oxide and for numerous practical appl... more Titanium dioxide has been studied for many years as a model oxide and for numerous practical applications. The aim of this investigation was the effect of cationic polysaccharide (chitosan, Fig. 1) on the electrokinetic behaviour of TiO2 suspensions in NaCl solution at different pH. Chitosan was used because its molecules exhibit various biomedical activities such as antimicrobial, antifungal, anti-allergic, anti-tumour and immune-activating effects. Moreover, chitosan protective barrier can retard ripening and water loss as well as reduce the destruction of products. Besides, because of its positive charge, chitosan strongly interacts with cell membranes and mucosal surfaces, which can be useful in drug delivery systems. TiO2 (P-25, Degussa) was purified by the procedure described by Preočanin and Kallay [1]. The electrokinetic behaviour of chitosan-treated TiO2 suspensions was determined mainly with the help of an optical analyzer and by dynamic light scattering method. The isoele...
Colloids and Interfaces
The characteristics of the wetting process of the porous surface of silica gel when penetrated by... more The characteristics of the wetting process of the porous surface of silica gel when penetrated by base liquids (water and n-octane), ethanol and stable drug systems (naproxen, ibuprofen and cyclosporine A), as biologically active substances in two ethanol concentrations, were determined by the wetting rate vs. time. The tests were performed for contacted and non-contacted plates with the vapours of the wetting liquid. Thin-layer liquid chromatography was used to determine the penetration rate of the SiO2-coated plates, taking into account the linear dependence consistent with the Washburn equation. Additionally, the changes in the adhesive tension ΔG were determined for the tested drugs. Drug stability tests were conducted using the dynamic light scattering technique and microelectrophoresis. The penetration time of the plate depends on the properties and structure of the wetting liquid droplets. The types of interactions (dispersive, electrostatic and hydrogen bonding) formed betwe...
Molecules
Chitosan-based nanoparticles (chitosan-based nanocomposites; chitosan nanoparticles; ChNPs) are p... more Chitosan-based nanoparticles (chitosan-based nanocomposites; chitosan nanoparticles; ChNPs) are promising materials that are receiving a lot of attention in the last decades. ChNPs have great potential as nanocarriers. They are able to encapsulate drugs as well as active compounds and deliver them to a specific place in the body providing a controlled release. In the article, an overview has been made of the most frequently used preparation methods, and the developed applications in medicine. The presentation of the most important information concerning ChNPs, especially chitosan’s properties in drug delivery systems (DDS), as well as the method of NPs production was quoted. Additionally, the specification and classification of the NPs’ morphological features determined their application together with the methods of attaching drugs to NPs. The latest scientific reports of the DDS using ChNPs administered orally, through the eye, on the skin and transdermally were taken into account.
Molecules
Poly(ethylene terephthalate)—PET—is one of the most frequently used polymers in biomedical applic... more Poly(ethylene terephthalate)—PET—is one of the most frequently used polymers in biomedical applications. Due to chemical inertness, PET surface modification is necessary to gain specific properties, making the polymer biocompatible. The aim of this paper is to characterize the multi-component films containing chitosan (Ch), phospholipid 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), immunosuppressant cyclosporine A (CsA) and/or antioxidant lauryl gallate (LG) which can be utilized as a very attractive material for developing the PET coatings. Chitosan was employed owing to its antibacterial activity and also its ability to promote cell adhesion and proliferation favorable for tissue engineering and regeneration purposes. Moreover, the Ch film can be additionally modified with other substances of biological importance (DOPC, CsA and LG). The layers of varying compositions were prepared using the Langmuir—Blodgett (LB) technique on the air plasma-activated PET support. Then their na...
Solution spreading and Langmuir-Blodgett/Schaefer techniques were used for preparation of chitosa... more Solution spreading and Langmuir-Blodgett/Schaefer techniques were used for preparation of chitosan/phospholipid (DPPC) films on air plasma treated polyethylene terephthalate (PET) plates. The surface wetting properties were determined based on the measurements of the advancing and receding contact angles of water, formamide and diiodomethane. The contact angle hysteresis model of Chibowski was applied to estimate the total surface free energy values. The coatings properties were found to be affected by molecular organisation and packing depending on the preparation technique. Phospholipid molecules modified the chitosan film surface by changing the kind and magnitude of interactions, which is revealed in the values of surface free energy. These findings may be helpful for the development of new generation polymersupported biocompatible coatings with anti-thrombogenic and antibactericidal properties, thus expanding the spectrum of chitosan applications.
Physicochemical Problems of Mineral Processing, 2019
The production of preparations, whose destination action takes place in close proximity to living... more The production of preparations, whose destination action takes place in close proximity to living cells, increases the necessity to carry out studies concerning the determination of the biomaterial surface effect on the cellular response. In achieving this goal, physicochemical characteristic of the surface can be helpful. This can be established based on topography, chemical composition, wettability, and surface energy analysis. In addition, determining the changes of these properties which can occur as a result of surface modification will allow prediction of cell behaviour when contacting with biomaterial. In the study, the Langmuir-Blodgett technique was used. It enabled the transfer of the Langmuir monolayer formed from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) to a solid support. The DPPC film imitated a natural biological membrane capable of interacting with the components of the liquid subphase: chitosan (Ch), hyaluronic acid (HA) and/or titanium dioxide (TiO2). Dep...
Materials Science and Engineering: C
In this paper, we propose a method of obtaining multi-component surface coatings on PEEK polymer,... more In this paper, we propose a method of obtaining multi-component surface coatings on PEEK polymer, which is becoming increasingly interested in a very wide branch of medicine - orthopedics. Thanks to the plasma techniques used and due to the presence of chitosan, the materials obtained are characterized by sterility, antisepticity, can accelerate wound healing, and serve as a drug delivery system directly to the tissues in need. In addition, the use of ternary Langmuir-Blodgett (lipid-sterol, peptide) films has resulted in significant change of surfaces polarity. The physico-chemical properties of the ternary Langmuir films obtained on the water subphase were tested exploiting Langmuir trough and a Brewster angle microscope. Then they were transferred to the modified surfaces of the solid PEEK polymer, where changes in wettability as well as surface free energy were determined by the type of substrate/coating and the hybrid composition. Additionally, surface chemistry was studied applying time of flight secondary ion mass spectrometry.
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Papers by Agnieszka Wiącek