scholarly journals Nanostructured Polystyrene Doped with Acetylsalicylic Acid and Its Antibacterial Properties

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3609
Author(s):  
Dominik Fajstavr ◽  
Klára Neznalová ◽  
Nikola Slepičková Kasálková ◽  
Silvie Rimpelová ◽  
Kateřina Kubičíková ◽  
...  
Keyword(s):  
Surface Chemistry ◽  
Acetylsalicylic Acid ◽  
Antibacterial Properties ◽  
Laser Pulses ◽  
Casting Method ◽  
Krypton Fluoride ◽  
Periodic Surface ◽  
Nanostructured Surfaces ◽  
Altered Surface ◽  
Selection Of

Homogeneous polystyrene foils doped with different concentrations of acetylsalicylic acid were prepared by the solvent casting method. The surface morphology and surface chemistry of as-prepared foils were characterized in detail. Excimer laser (krypton fluoride, a wavelength of 248 nm) was used for surface nanopatterning of doped polystyrene foils. Certain combinations of laser fluence and number of laser pulses led to formation of laser-induced periodic surface structures (LIPSS) on the exposed surface. Formation of the pattern was affected by the presence of a dopant in the polystyrene structure. Significant differences in surface chemistry and morphology of laser-treated foils compared to both pristine and doped polystyrene were detected. The pattern width and height were both affected by selection of input excimer exposure conditions, and the amount of 6000 pulses was determined as optimal. The possibility of nanostructuring of a honeycomb-like pattern doped with acetylsalicylic acid was also demonstrated. Selected nanostructured surfaces were used for study the antibacterial properties for a model bacteria strain of S. aureus. The combination of altered surface chemistry and morphology of polystyrene was confirmed to have an excellent antibacterial properties.

scholarly journals LIPSS Structures Induced on Graphene-Polystyrene Composite

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3460 ◽  
Author(s):  
Dominik Fajstavr ◽  
Klára Neznalová ◽  
Václav Švorčík ◽  
Petr Slepička
Keyword(s):  
Chemical Properties ◽  
Laser Pulses ◽  
Periodic Pattern ◽  
Krypton Fluoride ◽  
Periodic Surface ◽  
Laser Modification ◽  
Force Microscopy ◽  
Periodic Surface Structure ◽  
Atomic Force ◽  
Physico Chemical

A laser induced periodic surface structure (LIPSS) on graphene doped polystyrene was prepared by the means of a krypton fluoride (KrF) laser with the wavelength of 248 nm and precisely desired physico-chemical properties were obtained for the structure. Surface morphology after laser modification of polystyrene (PS) doped with graphene nanoplatelets (GNP) was studied. Laser fluence values of modifying laser light varied between 0–40 mJ·cm−2 and were used on polymeric PS substrates doped with 10, 20, 30, and 40 wt. % of GNP. GNP were incorporated into PS substrate with the solvent casting method and further laser modification was achieved with the same amount of laser pulses of 6000. Formed nanostructures with a periodic pattern were examined by atomic force microscopy (AFM). The morphology was also studied with scanning electron microscopy SEM. Laser irradiation resulted in changes of chemical composition on the PS surface, such as growth of oxygen concentration. This was confirmed with energy-dispersive X-ray spectroscopy (EDS).

SOMES: A REVIEW ON COMPOSITION, FORMULATION METHODS AND EVALUATIONS OF DIFFERENT TYPES OF “SOMES” DRUG DELIVERY SYSTEM

2020 ◽  
pp. 7-18
Author(s):  
KUSUMA PRIYA M. D. ◽  
VINOD KUMAR ◽  
DAMINI V. K. ◽  
ESWAR K. ◽  
KADIRI RAJESH REDDY ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Sustained Release ◽  
Surface Chemistry ◽  
Drug Delivery System ◽  
Delivery System ◽  
Different Types ◽  
Potent Drug ◽  
Evaluation Parameters ◽  
Selection Of

Many drugs are available in the market for several diseases, disorder or even for a condition, but it is difficult to select a suitable carrier to attain maximum bioavailability and potential for a potent drug. Attaining a controlled and sustained release of a drug is purely focused on the selection of a carrier (natural, synthetic and hybrid) like nanosomes. Nanosomes have become a prominent tool in the field of pharmacy. Nanosomes are small uniform structures which deliver the drug to the specific targeted site, which mainly depends upon the presence of ligands, shape, size and surface chemistry. Nanosomes are available in various types which include Niosomes, Liposomes, Electrosomes, Aquasomes, Transfersomes, Phytosomes, Enzymosomes, Ethosomes, Invasome and Sphingosomes. In general, all these nanosomes are quite similar in nature with minute differences in their vesicular characteristics and composition. This review traces various ‘somes’ composition and their role in the formulation, applications, advantages, disadvantages, common formulation procedures and evaluation parameters.

scholarly journals Bacteria Death and Osteoblast Metabolic Activity Correlated to Hydrothermally Synthesised TiO2 Surface Properties

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1201 ◽  
Author(s):  
Alka Jaggessar ◽  
Asha Mathew ◽  
Tuquabo Tesfamichael ◽  
Hongxia Wang ◽  
Cheng Yan ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Properties ◽  
Metabolic Activity ◽  
Mechanical Stability ◽  
Antibacterial Properties ◽  
Mechanical Tests ◽  
Nanostructured Surfaces ◽  
Surface Contact Angle ◽  
Cellular Metabolic Activity ◽  
Structure Height

Orthopaedic surgery comes with an inherent risk of bacterial infection, prolonged antibiotic therapy and revision surgery. Recent research has focused on nanostructured surfaces to improve the bactericidal and osseointegrational properties of implants. However, an understanding of the mechanical properties of bactericidal materials is lacking. In this work, the surface properties of hydrothermal TiO2 nanostructured surfaces are investigated for their effect on bactericidal efficiency and cellular metabolic activity of human osteoblast cells. TiO2 nanostructures, approximately 307 nm in height and 14 GPa stiffness, were the most effective structures against both gram-positive (Staphylococcus aureus) and gram-negative (Pseudomonas aeruginosa) bacteria. Statistical analysis significantly correlated structure height to the death of both bacteria strains. In addition, the surface contact angle and Young’s modulus were correlated to osteoblast metabolic activity. Hydrophilic surfaces with a contact angle between 35 and 50° produced the highest cellular metabolic activity rates after 24 hours of incubation. The mechanical tests showed that nanostructures retain their mechanical stability and integrity over a long time-period, reaffirming the surfaces’ applicability for implants. This work provides a thorough examination of the surface, mechanical and wettability properties of multifunctional hydrothermally synthesised nanostructured materials, capable of killing bacteria whilst improving osteoblast metabolic rates, leading to improved osseointegration and antibacterial properties of orthopaedic implants.

Laser interference ablation by ultrashort UV laser pulses via diffractive beam management

2020 ◽  
Vol 9 (1-2) ◽  
pp. 41-52 ◽  
Author(s):  
Jan-Hendrik Klein-Wiele ◽  
Andreas Blumenstein ◽  
Peter Simon ◽  
Jürgen Ihlemann
Keyword(s):  
Laser Pulses ◽  
Diffractive Optical Elements ◽  
Uv Laser ◽  
Laser Interference ◽  
Periodic Patterns ◽  
Optical Elements ◽  
Periodic Surface ◽  
Coherent Beams ◽  
Surface Patterns ◽  
Computer Generated Holograms

AbstractThe fabrication of periodic surface patterns on various materials by ultrashort ultraviolet (UV) laser pulses is reviewed. Laser interference ablation using two or more coherent beams leads to deterministic, strictly periodic patterns. The generation of the interfering beams is accomplished by diffractive optical elements like gratings, grating systems or computer-generated holograms. The recombination of the diffracted beams is performed by optical imaging or diffractive beam management. Ultrashort UV pulses are especially suited for generating micron- to submicron-sized deterministic periodic patterns on metals and semiconductors.

scholarly journals Model-Driven Controlled Alteration of Nanopillar Cap Architecture Reveals its Effects on Bactericidal Activity

2020 ◽  
Vol 8 (2) ◽  
pp. 186 ◽  
Author(s):  
Taiyeb Zahir ◽  
Jiri Pesek ◽  
Sabine Franke ◽  
Jasper Van Pee ◽  
Ashish Rathore ◽  
...  
Keyword(s):  
Bactericidal Activity ◽  
Cell Envelope ◽  
Antibacterial Properties ◽  
Biophysical Model ◽  
Surface Measurement ◽  
Dependent Manner ◽  
Bending Rigidity ◽  
Nanostructured Surfaces ◽  
Model Driven ◽  
Antibacterial Surfaces

Nanostructured surfaces can be engineered to kill bacteria in a contact-dependent manner. The study of bacterial interactions with a nanoscale topology is thus crucial to developing antibacterial surfaces. Here, a systematic study of the effects of nanoscale topology on bactericidal activity is presented. We describe the antibacterial properties of highly ordered and uniformly arrayed cotton swab-shaped (or mushroom-shaped) nanopillars. These nanostructured surfaces show bactericidal activity against Staphylococcus aureus and Pseudomonas aeruginosa. A biophysical model of the cell envelope in contact with the surface, developed ab initio from the infinitesimal strain theory, suggests that bacterial adhesion and subsequent lysis are highly influenced by the bending rigidity of the cell envelope and the surface topography formed by the nanopillars. We used the biophysical model to analyse the influence of the nanopillar cap geometry on the bactericidal activity and made several geometrical alterations of the nanostructured surface. Measurement of the bactericidal activities of these surfaces confirms model predictions, highlights the non-trivial role of cell envelope bending rigidity, and sheds light on the effects of nanopillar cap architecture on the interactions with the bacterial envelope. More importantly, our results show that the surface nanotopology can be rationally designed to enhance the bactericidal efficiency.

Periodic Surface Damage in Germanium: The Spectrum in K→ Space and its Theoretical Interpretation

1981 ◽  
Vol 4 ◽  
Author(s):  
Jeff F. Young ◽  
J. E. Sipe ◽  
M. I. Gallant ◽  
J. S. Preston ◽  
H. M. Van Driel
Keyword(s):  
Surface Roughness ◽  
Fourier Transforms ◽  
Surface Damage ◽  
Laser Pulses ◽  
Theoretical Interpretation ◽  
Periodic Surface ◽  
Yag Laser ◽  
Damage Structure

ABSTRACTThe Fourier transforms of the grating-like damage patterns formed on the surface of Ge by single 1.06μm YAG laser pulses reveal a great deal of information about the damage structure. A theory is presented based on scattering from surface roughness which accurately accounts for both the spacing and orientation of the fringes produced at various angles of incidence by beams of different polarizations.

scholarly journals Laser-induced periodic surface structures on bismuth thin films with ns laser pulses below ablation threshold

2017 ◽  
Vol 7 (6) ◽  
pp. 1777 ◽  
Author(s):  
A. Reyes-Contreras ◽  
M. Camacho-López ◽  
S. Camacho-López ◽  
O. Olea-Mejía ◽  
A. Esparza-García ◽  
...  
Keyword(s):  
Thin Films ◽  
Ablation Threshold ◽  
Laser Pulses ◽  
Surface Structures ◽  
Periodic Surface

scholarly journals Preparation of Nanocomposite Alginate Fibers Modified with Titanium Dioxide and Zinc Oxide

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1040
Author(s):  
Dominik Borkowski ◽  
Izabella Krucińska ◽  
Zbigniew Draczyński
Keyword(s):  
Zinc Oxide ◽  
Titanium Dioxide ◽  
Antibacterial Properties ◽  
Natural Polymers ◽  
Nano Zinc Oxide ◽  
Nano Additives ◽  
Alginate Fibers ◽  
Nano Zinc ◽  
Nano Titanium Dioxide ◽  
Selection Of

Active dressings based on natural polymers are becoming increasingly popular on the market. One of such polymers is alginate, which is characterized by biodegradability, resorbability, has no carcinogenic properties, does not have allergenic or hemostatic properties, and has a confirmed lack of toxicity. However, this polymer does not show biocidal and biostatic properties, therefore the purpose of this research was to select the appropriate conditions for the production of calcium alginate fibers modified with nano titanium dioxide and nano zinc oxide. It was assumed that the presence of nano metal oxide fillers will give antibacterial properties to formed fibers, which were used to form nonwovens. The following article presents a comparative analysis of nonwovens made of alginate fibers, without nano additives, with nonwovens made of alginate fibers containing in their structure 7% titanium dioxide and nonwovens made of alginate fibers containing 2% ZnO. The selection of the nano additive content was determined by the spinning ability of the developed polymer solutions. Based on the results contained in the article, it was found that the introduction of modifiers in the structure of fibers increases the diameter of the fiber pores, which improves the sorption and retention properties of the obtained fibers, and also gives differentiated antibacterial properties to the obtained nonwovens depending on the type of nano additive used. Greater activity against Escherichia coli, Staphylococcus aureus strains and Aspergillus Niger molds was shown in nonwovens made of 2% ZnO modified fibers compared to nonwovens made from TiO2 modified fibers.

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