Search

Wettability measurements were performed for aqueous dispersions of native and modified corn, potato, and pea starch granules deposited on glass plates by the thin layer method using test liquids of a different chemical nature (polar water and formamide or non-polar diiodomethane). High values of the determination coefficient R2 confirm that the linear regression model describes the relationship between the wetting time and the square of the penetration distance very well, indicating the linear nature of the Washburn relationship. A change in free energy (enthalpy) during the movement of the liquid in the porous layer was determined for all starches before and after modification in contact with test liquids. Wetting times for polar liquids increased significantly (from 3 to 4 fold), especially for corn starch. The lower the value of the adhesive tension, the easier the wetting process takes place, and consequently, the adsorption process is facilitated. Adhesive tension for polar substances applies to the adsorption of hydrophilic substances, while in the case of apolar substances, adhesive tension applies to the adsorption of hydrophobic substances. For the adsorption of gallic acid on starch, the relationships obtained for polar substances are crucial. The adsorption of gallic acid by forming hydrogen bonds or, more generally, donor–acceptor (acid–base) bonds is definitely higher for corn starch than other starches. Therefore, this starch has the most significant potential for use as a carrier of gallic acid or, more broadly, compounds from the polyphenol group. [ABSTRACT FROM AUTHOR]

Dermatology and cosmetology currently prioritize healthy, youthful-looking skin. As a result, research is being conducted worldwide to uncover natural substances and carriers that allow for controlled release, which could aid in the battle against a variety of skin illnesses and slow the aging process. This study examined the biological and physicochemical features of novel hydrogels containing cannabidiol (CBD) and α-terpineol (TER). The hydrogels were obtained from ε-caprolactone (CL) and poly(ethylene glycol) (PEG) copolymers, diethylene glycol (DEG), poly(tetrahydrofuran) (PTHF), 1,6-diisocyanatohexane (HDI), and chitosan (CHT) components, whereas the biodegradable oligomers were synthesized using the enzyme ring-opening polymerization (e-ROP) method. The in vitro release rate of the active compounds from the hydrogels was characterized by mainly first-order kinetics, without a "burst release". The antimicrobial, anti-inflammatory, cytotoxic, antioxidant, and anti-aging qualities of the designed drug delivery systems (DDSs) were evaluated. The findings indicate that the hydrogel carriers that were developed have the ability to scavenge free radicals and impact the activity of antioxidant enzymes while avoiding any negative effects on keratinocytes and fibroblasts. Furthermore, they have anti-inflammatory qualities by impeding protein denaturation as well as the activity of proteinase and lipoxygenase. Additionally, their ability to reduce the multiplication of pathogenic bacteria and inhibit the activity of collagenase and elastase has been demonstrated. Thus, the developed hydrogel carriers may be effective systems for the controlled delivery of CBD, which may become a valuable tool for cosmetologists and dermatologists. [ABSTRACT FROM AUTHOR]

Polysaccharide-based systems have very good emulsifying and stabilizing properties, and starch plays a leading role. Their modifications should add new quality features to the product to such an extent that preserves the structure-forming properties of native starch. The aim of this manuscript was to examine the physicochemical characteristics of the combinations of starch with phospholipids or lysozymes and determine the effect of starch modification (surface hydrophobization or biological additives) and preparation temperature (before and after gelatinization). Changes in electrokinetic potential (zeta), effective diameter, and size distribution as a function of time were analyzed using the dynamic light scattering and microelectrophoresis techniques. The wettability of starch-coated glass plates before and after modification was checked by the advancing and receding contact angle measurements, as well as the angle hysteresis, using the settle drop method as a complement to profilometry and FTIR. It can be generalized that starch dispersions are more stable than analogous n-alkane/starch emulsions at room and physiological temperatures. On the other hand, the contact angle hysteresis values usually decrease with temperature increase, pointing to a more homogeneous surface, and the hydrophobization effect decreases vs. the thickness of the substrate. Surface hydrophobization of starch carried out using an n-alkane film does not change its bulk properties and leads to improvement of its mechanical and functional properties. The obtained specific starch-based hybrid systems, characterized in detail by switchable wettability, give the possibility to determine the energetic state of the starch surface and understand the strength and specificity of interactions with substances of different polarities in biological processes and their applicability for multidirectional use. [ABSTRACT FROM AUTHOR]

LL-37 is the only member of the cathelicidin-type host defense peptide family in humans. It exhibits broad-spectrum bactericidal activity, which represents a distinctive advantage for future therapeutic targets. The presence of choline in the growth medium for bacteria changes the composition and physicochemical properties of their membranes, which affects LL-37's activity as an antimicrobial agent. In this study, the effect of the LL-37 peptide on the phospholipid monolayers at the liquid–air interface imitating the membranes of Legionella gormanii bacteria was determined. The Langmuir monolayer technique was employed to prepare model membranes composed of individual classes of phospholipids—phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), cardiolipin (CL)—isolated from L. gormanii bacteria supplemented or non-supplemented with exogenous choline. Compression isotherms were obtained for the monolayers with or without the addition of the peptide to the subphase. Then, penetration tests were carried out for the phospholipid monolayers compressed to a surface pressure of 30 mN/m, followed by the insertion of the peptide into the subphase. Changes in the mean molecular area were observed over time. Our findings demonstrate the diversified effect of LL-37 on the phospholipid monolayers, depending on the bacteria growth conditions. The substantial changes in membrane properties due to its interactions with LL-37 enable us to propose a feasible mechanism of peptide action at a molecular level. This can be associated with the stable incorporation of the peptide inside the monolayer or with the disruption of the membrane leading to the removal (desorption) of molecules into the subphase. Understanding the role of antimicrobial peptides is crucial for the design and development of new strategies and routes for combating resistance to conventional antibiotics. [ABSTRACT FROM AUTHOR]

Porous starch can be applied as an adsorbent and encapsulant for bioactive substances in the food and pharmaceutical industries. By using appropriate modification methods (chemical, physical, enzymatic, or mixed), it is possible to create pores on the surface of the starch granules without disturbing their integrity. This paper aimed to analyze the possibility of obtaining a porous structure for native corn, potato, and pea starches using a combination of ultrasound, enzymatic digestion, and freeze-drying methods. The starch suspensions (30%, w/w) were treated with ultrasound (20 kHz, 30 min, 20 °C), then dried and hydrolyzed with amyloglucosidase (1000 U/g starch, 50 °C, 24 h, 2% starch suspension). After enzyme digestion, the granules were freeze-dried for 72 h. The structure of the native and modified starches were examined using VIS spectroscopy, SEM, ATR-FTIR, and LTNA (low-temperature nitrogen adsorption). Based on the electrophoretic mobility measurements of the starch granules using a laser Doppler velocimeter, zeta potentials were calculated to determine the surface charge level. Additionally, the selected properties such as the water and oil holding capacities, least gelling concentration (LGC), and paste clarity were determined. The results showed that the corn starch was the most susceptible to the combined modification methods and was therefore best suited for the production of porous starch. [ABSTRACT FROM AUTHOR]

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 nanostructure, molecular distribution, surface chemistry and wettability were determined by atomic force microscopy (AFM), time-of-flight secondary ion mass spectrometry (TOF-SIMS), X-ray photoelectron spectroscopy (XPS), contact angle (CA) measurements and the surface free energy and its components' determination, respectively. The obtained results show clearly the dependence of the surface properties of the films on the molar ratio of components and allow for a better understanding of the coating organization and mechanisms of interactions at the molecular level both inside the films and between the films and the polar/apolar liquids imitating the environment of different properties. The organized layers of this type can be helpful in gaining control over the surface properties of the biomaterial, thus getting rid of the limitations in favor of increased biocompatibility. This is a good basis for further investigations on the correlation of the immune system response to the presence of biomaterial and its physicochemical properties. [ABSTRACT FROM AUTHOR]

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 characteristics of the patient. The obtained surfaces were examined in terms of wettability and surface-free energy changes. Additionally, FTIR (Fourier Transformation Infrared Spectrometry) and SIMS (Secondary Ion Mass Spectrometry) were applied to establish and control the coating composition. Simultaneously the structure of coatings was visualized with the aid of SEM (Scanning Electron Microscopy). Finally, the obtained systems were incubated in SBF (Simulated Body Fluid) to verify the modifications' influence on the bioactivity/biocompatibility of the PEEK surface. Different structures with variable compositions, as well as changes of the wettability, were observed depending on the applied modification. In addition, the incubation in SBF suggested that the bioglass-chitosan ratio influenced the formation of apatite-like structures on the modified PEEK surfaces. [ABSTRACT FROM AUTHOR]

Surface properties of polyethylene terephthalate (PET) coated with the ternary monolayers of the phospholipid 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), the immunosuppressant cyclosporine A (CsA), and the antioxidant lauryl gallate (LG) were examined. The films were deposited, by means of the Langmuir–Blodgett (LB) technique, on activated by air low temperature plasma PET plates (PETair). Their topography and surface chemistry were determined with the help of atomic force microscopy (AFM) and time-of-flight secondary ion mass spectrometry (TOF-SIMS), respectively, while wettability was evaluated by the contact angle measurements. Then, the surface free energy and its components were calculated from the Lifshitz–van der Waals/Acid–Base (LWAB) approach. The AFM imaging showed that the Langmuir monolayers were transferred effectively and yielded smoothing of the PETair surface. Mass spectrometry confirmed compatibility of the quantitative and qualitative compositions of the monolayers before and after the transfer onto the substrate. Moreover, the molecular arrangement in the LB films and possible mechanisms of DOPC-CsA-LG interactions were determined. The wettability studies provided information on the type and magnitude of the interactions that can occur between the biocoatings and the liquids imitating different environments. It was found that the changes from open to closed conformation of CsA molecules are driven by the hydrophobic environment ensured by the surrounding DOPC and LG molecules. This process is of significance to drug delivery where the CsA molecules can be released directly from the biomaterial surface by passive diffusion. The obtained results showed that the chosen techniques are complementary for the characterization of the molecular organization of multicomponent LB films at the polymer substrate as well as for designing biocompatible coatings with precisely defined wettability. [ABSTRACT FROM AUTHOR]

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 between the silanol surface groups of the silica gel and the groups contained in the adsorbate particles are also very important factors. The greater the impact force, the slower the wetting process due to the strong penetration of the liquid into the pores of the substrate. The characteristics of the drug wetting/stability process may contribute to the development of their new forms, creating delivery systems with greater efficiency and lower side effects. [ABSTRACT FROM AUTHOR]

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 it slow 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 increased SFE of the PET surface with the lipid monolayers due to specific organisation of molecules within the chitosan scaffold. The most promising combination of surface modification for tissue engineering applications seems to be the PETair/Ch/DPPC-Chol system. [ABSTRACT FROM AUTHOR]

The properties of one-component and mixed monolayers of phospholipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and polypeptide cyclosporine A (CsA) on the chitosan subphase were studied. DPPC is the main component that builds biological membranes, and CsA is an immunosuppressive drug typically used in medicine to prevent transplant rejections. The stability and reversibility of compression of these insoluble monolayers in the presence of chitosan (Ch) were examined by the Langmuir technique. The stability of the monolayers depended on the monolayer composition as well as the initial pressure (p0) of the relaxation process. The smallest changes in the relative pressure as a function of time were obtained at p0 = 10 mN/m. During compression-decompression cycles, the effect of chitosan was noticeable and caused isotherm shifts. [ABSTRACT FROM AUTHOR]

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). Depending on the type and strength of interactions of phospholipid molecules with the components of the subphase, the films obtained on the solid support were characterized by specific surface properties. Their characteristics based mainly on values of the work of adhesion in connection with films topography, allowed for statement that it is possible to form semi-interpenetrating Ch network in which HA is entrapped, contributing to the enhanced adhesion of the DPPC film, additionally intensified by TiO2 inclusion. This type of research permit for better understanding of the interactions at the interface, cell membrane-Ch/HA/TiO2 and can be important in the creation of a new generation of skin or tissue substitutes. [ABSTRACT FROM AUTHOR]

Polyetheretherketone (PEEK) is a highly biocompatible polymer widely used in medicine as an implant production material. In this article, the PEEK surface was characterized in terms of its wettabillity properties after the physicochemical modifications by treatment with the low‐temperature air plasma and covering with the Langmuir–Blodgett (LB) monolayers of polypeptide (cyclosporine A, CsA) and/or phospholipid (1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine, DPPC). The LB deposition was preceded by the analysis of miscibility and morphology of monolayers at the air/water interface by means of the Langmuir technique and Brewster angle microscopy (BAM). Then, wettability of the polymer‐supported films was evaluated by the contact angle measurements of three probe liquids of different characters (two polar—water and formamide, one apolar—diiodomethane). The measured contact angles allowed for determination of the surface free energy and its components based on the Lifshitz‐van der Waals/acid–base (LWAB) approach. Some relations between the kind and magnitude of interactions within the model membranes on the water subphase and those of the PEEK‐supported membranes with the liquids were found out. The results allowed obtaining the interesting models of biological coatings with potential applications. [ABSTRACT FROM AUTHOR]

The paper presents changes in wettability of the unmodified and modified polyethylene terephthalate (PET) surfaces. A low temperature air plasma was used to activate the polymer surface and to change its hydrophilic-hydrophobic properties. Then, using the Langmuir-Blodgett technique, the Langmuir monolayers of l,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and cyclosporine A (CsA) with different molar fractions, i.e. χ=0.25, 0.50, 0.75, were deposited onto the activated PET surface. Besides, a series of DPPC and CsA monolayers was also transferred onto the chitosan layer, previously produced on the plasma treated PET by the dip- coating method. The wetting properties of such modified PET surfaces were then investigated by the contact angle measurements using three test liquids with well-known surface tension components. The obtained results show that wettability depends on the composition of the deposited DPPC/CsA layer with or without chitosan. Presence of chitosan makes the DPPC/CsA film surface more polar due to specific organization of molecules that expose their polar heads outside. [ABSTRACT FROM AUTHOR]

In the present paper, cold plasma-activated and chitosan-coated polyetheretherketone (PEEK) was covered with thin films of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, cholesterol, cyclosporine A, and their mixtures using the Langmuir-Blodgett technique. The thermodynamic function, i.e., surface free energy, of those systems was determined based on the contact angle hysteresis (CAH) approach. This parameter seems to be essential in determination of cell adhesion to polymeric materials and molecular interactions with living tissues. The obtained results show that the wettability and surface free energy of PEEK can be changed depending on the composition of the coating. [ABSTRACT FROM AUTHOR]

The Langmuir-Blodgett technique was used to transfer the monolayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) from the subphase containing chitosan (Ch) and/or titanium(IV) oxide (TiO2) and/or hyaluronic acid (HA) on glass plates after a lowtemperature air plasma treatment. The surface free energy and its components were determined on the basis of advancing and receding contact angle measurements of water (W), formamide (F), and diiodomethane (DM). To estimate the total surface free energy (𝛾s tot), the contact angle hysteresis (CAH) model was used, and the obtained data were compared with the results calculated from the Lifshitz-van der Waals/acid.base (LWAB) approach. It was found that the subphase components modify the surface of the phospholipid monolayer by changing the type and magnitude of interactions. They were reflected as significant differences in the obtained values of total surface free energy and its components. These findings can help in the development of composite materials, thereby expanding the spectrum of applications for chitosan, TiO2, and HA, as well as understanding the interactions between biomaterial and cell. [ABSTRACT FROM AUTHOR]

Abstract: Wettability properties of polyetheretherketone (PEEK) activated and non‐activated by nitrogen plasma have been investigated. Moreover, the PEEK plates were covered with antibacterial chitosan and its wettability properties were also investigated. Surface topography was determined using SEM and optical profilometry and surface composition by FT‐IR and XPS. For determination of apparent surface free energy, the hysteresis approach (CAH), acid base (LWAB), and Owens–Wendt (O–W) theory were used. The equilibrium contact angles were calculated from the Tadmor theory and further used for apparent surface energy calculation applying the above‐mentioned approaches. Due to the surface plasma activation both the roughness of the surface and the polar component of apparent surface free energy increased. It is shown that nitrogen plasma activation of PEEK surface increases the adhesion of chitosan to the surface due to the combination effect of: (i) the increase in surface roughness, (ii) introducing the polar groups onto the surface. [ABSTRACT FROM AUTHOR]

In this paper, the wettability of chitosan/phospholipid (1,2-dipalmitoylsn-glycero-3-phosphocholine - DPPC), chitosan/lipid (cholesterol - Choi) and chitosan/protein (cyclosporine A - CsA) films on air plasma activated polyetheretherketone (PEEK) plates was studied. The layers were prepared using the solution spreading technique and their surface wetting properties were determined based on the measurements of the advancing and receding contact angles of water, formamide and diiodomethane. Moreover, based on the contact angle hysteresis model of Chibowski, values of total surface free energy were estimated. Significant changes in PEEK polarity were observed after plasma activation and modifications with Ch/DPPC, Ch/Chol and Ch/CsA layers. These molecules modulate the chitosan film surface by changing the type and magnitude of interactions, which is revealed in the values of surface free energy'. These results may be important for the development and implementation of highly biocompatible bone substitution polymers coated with chitosan film with antifungal and anti-bactericidal properties. Those systems based on chitosan may also carry and release biologically active substances which could be relevant in the new generation of drug delivery systems. [ABSTRACT FROM AUTHOR]

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 polymer-supported biocompatible coatings with anti-thrombogenic and anti-bactericidal properties, thus expanding the spectrum of chitosan applications. [ABSTRACT FROM AUTHOR]

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 antibacterial properties. Ch and TiO2 mostly affect S. aureus monolayer structure during compression. They can enhance the permeability of biological membranes leading to the bacteria cell death. In turn, HA has a greater impact on the thickness of E. coli film. [ABSTRACT FROM AUTHOR]

Abstract: Adsorption of dipalmitoylphosphatidylcholine (DPPC) from NaCl solution on SiO2 particles in suspension was investigated by means of zeta potential and effective diameter measurements as a function of pH using dynamic light scattering. Also, the zeta potential of DPPC aggregates in the same environment was measured. By comprising the results, it was found that DPPC adsorbs on the silica surface, which resulted in decrease of negative zeta potential of the silica suspension. However, DPPC stabilized the SiO2 particle aggregates, which resulted in smaller and smoother changes of the aggregate size during 2h-time experiments, probably due to steric stabilization. In the next series of the experiments the effect of enzymes (phospholipase A2 or lipase Candida Cylindracea) on the behavior of the silica/DPPC suspension was studied. The kind of the enzymes; the hydrolysis products, which were palmitic acid and lysophosphatidylcholine (or glycerylphosphorylcholine), and pH influenced the suspension zeta potential. The lipase was found to be a more active enzyme, both at natural pH=5.8 and pH=8. The evaluated parameters connected with the adsorption process and resulting from enzyme action seem to be helpful for further characterization of the silica/DPPC system, which is discussed in the paper. [Copyright &y& Elsevier]

Abstract: The measurements of the penetration rates of n-octane, water and formamide on bare commercial Al2O3 plates and those covered by dipalmitoylphosphatidylcholine (DPPC) or DPPC+enzyme lipase from 1mM NaCl solution were conducted. Influence of phospholipid and enzyme on the energetic properties of the solid surface was discussed by means of the modified Washburn equation. Additionally, to explain behavior of Al2O3 systems, the measurements of the zeta potential of the same alumina (powder) suspension in NaCl after adding DPPC or DPPC+enzyme lipase, were performed. The van Oss et al.''s approach to interfacial free energy interactions was applied to determine solid surface free energy components after DPPC or lipase treatment. Moreover the work of water spreading was calculated for better description of such systems. On the basis of the obtained results, it is suggested that adsorption of DPPC on the Al2O3 plates increased the hydrophobic character of the alumina surface but after the enzyme action the products of dipalmitoylphosphatidylcholine hydrolysis by lipase, which are glycerylphosphorylcholine and palmitic acid, increased its hydrophilic character again. The most striking were the changes of the electron-donor (γ s −) parameter (which ranged from 15 to 34mJ/m2) and those of acid–base component in the range 13–18mJ/m2 delivering interesting information about the change of Al2O3 surface character. Some correlations found between the surface free energy components and the zeta potential of alumina suspension are discussed. The obtained relationships show usefulness of the applied techniques: the thin layer wicking method and electrokinetic measurements to investigate the enzyme effect on wettability changes of the phospholipid-covered alumina surface. [Copyright &y& Elsevier]