229 research outputs found
Advances in Cancer Treatment: Role of Nanoparticles
This chapter is devoted to the advances in the field of nanoparticles-mediated cancer treatment. A special attention is devoted to the use of magnetite and silver nanoparticles. The synthesis and properties of Fe3O4 and Ag nanoparticles as contrast or antitumoral agents as monolith or component of more complex systems such as polymer matrix composite materials based on: polymers (chitosan, collagen, polyethylene glycol, polyacrylates, and polymethacrylates, polylactic acid, etc.) and various antitumoral agents (cytostatics, natural agents and even nanoparticles-magnetite, silver, or gold) are discussed. Special attention is paid for the benefits and risks of using silver and magnetite nanoparticles. In both cases, the discussion focuses on aspects related to diagnosis and treatment of cancer. The influence of size and shape [1-3] is important from the materials characteristics as well as from the biological points of view. The role of magnetite is also analyzed from the point of view of its influence on the delivery of different components of interests (antitumoral components, analgesics/anti-inflammatory agents, etc.). The potentiating effect of the nanoparticles over the cytostatics and natural components is highlighted
Kinetic Release Studies of Antibiotic Patches for Local Transdermal Delivery.
This study investigates the usage of electrohydrodynamic (EHD)-3D printing for the fabrication of bacterial cellulose (BC)/polycaprolactone (PCL) patches loaded with different antibiotics (amoxicillin (AMX), ampicillin (AMP), and kanamycin (KAN)) for transdermal delivery. The composite patches demonstrated facilitated drug loading and encapsulation efficiency of drugs along with extended drug release profiles. Release curves were also subjected to model fitting, and it was found that drug release was optimally adapted to the Higuchi square root model for each drug. They performed a time-dependent and diffusion-controlled release from the patches and followed Fick's diffusion law by the Korsmeyer-Peppas energy law equation. Moreover, produced patches demonstrated excellent antimicrobial activity against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) strains, so they could be helpful in the treatment of chronic infectious lesions during wound closures. As different tests have confirmed, various types of antibiotics could be loaded and successfully released regardless of their types from produced BC/PCL patches. This study could breathe life into the production of antibiotic patches for local transdermal applications in wound dressing studies and improve the quality of life of patients
Multifunctional materials for bone cancer treatment
The purpose of this review is to present the most recent findings in bone tissue engineering. Special attention is given to multifunctional materials based on collagen and collagen-hydroxyapatite composites used for skin and bone cancer treatments. The multi-functionality of these materials was obtained by adding to the base regenerative grafts proper components, such as ferrites (magnetite being the most important representative), cytostatics (cisplatin, carboplatin, vincristine, methotrexate, paclitaxel, doxorubicin), silver nanoparticles, antibiotics (anthracyclines, geldanamycin), and/or analgesics (ibuprofen, fentanyl). The suitability of complex systems for the intended applications was systematically analyzed. The developmental possibilities of multifunctional materials with regenerative and curative roles (antitumoral as well as pain management) in the field of skin and bone cancer treatment are discussed. It is worth mentioning that better materials are likely to be developed by combining conventional and unconventional experimental strategies
Editorial: Degradation of Cultural Heritage Artifacts: From Archaeometry to Materials Development
3D Propolis-Sodium Alginate Scaffolds: Influence on Structural Parameters, Release Mechanisms, Cell Cytotoxicity and Antibacterial Activity
FEN-C-YLP-130319-0065 BAPKO Project. UID/CTM/50025/2019In this study, the main aim was to fabricate propolis (Ps)-containing wound dressing patches using 3D printing technology. Different combinations and structures of propolis (Ps)-incorporated sodium alginate (SA) scaffolds were developed. The morphological studies showed that the porosity of developed scaffolds was optimized when 20% (v/v) of Ps was added to the solution. The pore sizes decreased by increasing Ps concentration up to a certain level due to its adhesive properties. The mechanical, swelling-degradation (weight loss) behaviors, and Ps release kinetics were highlighted for the scaffold stability. An antimicrobial assay was employed to test and screen antimicrobial behavior of Ps against Escherichia coli and Staphylococcus aureus strains. The results show that the Ps-added scaffolds have an excellent antibacterial activity because of Ps compounds. An in vitro cytotoxicity test was also applied on the scaffold by using the extract method on the human dermal fibroblasts (HFFF2) cell line. The 3D-printed SA-Ps scaffolds are very useful structures for wound dressing applications.publishersversionpublishe
Layered Composites Based on Recycled PET/Functionalized Woven Flax Fibres
Extended Abstract Plastic waste is generated by a variety of sources including packaging, automotive, consumer goods, electrical and electronics industries, leading to a significant growth in the volume of waste and the impetuous need to reduce it The paper aims at developing new layered composite materials based on recycled thermoplastic polymer (PETpolyethylene terephthalate) from the food industry reinforced with woven flax fiber functionalized with nano (micro) particles of titanium or alumina and testing the composite in terms of physico-mechanical (tensile strength, bending, shock, etc.), morphological (SEM), structural (FTIR), and thermal (Vicat) properties. Based on this technology, the new composite will exhibit improved physical, mechanical and thermal properties, as well as resistance to mold attack. In this regard, in the first stage, the surface of flax fibers were chemically modified using aluminum (AlCl3), and titanium (titanium butoxide) precursors followed by precipitation. The woven flax whose surface was functionalized with nano (micro) alumina or TiO2 particles were subsequently used to obtain layered composite materials. Layered composite materials were obtained by alternating functionalized / not functionalized woven flax fiber with sheets made from recycled PET. The recycled PET sheets and layered composites based on recycled PET and functionalized / not functionalized woven flax fiber were obtained by press molding using an electrical press at the following optimum parameters: plate temperature -254ºC, preheating time -8 min; pressing time -2 min; cooling time -15 min; pressing force -100 kN. Special attention must be paid to the pre-drying process (at 100-110ºC) to remove adsorbed water. In the absence of the pre-drying operation, the resulting sheets exhibit holes, porosity and discontinuities, making them unusable for the development of layered composite materials. Physical, mechanical and thermal analyses results for specimens of layered composite materials based on recycled PET / functionalised woven flax fiber show significantly improved values compared with the control samples obtained from recycled PET / not functionalized flax fiber. Improved mechanical and thermal properties are due to links developed at the woven flax fiber / polymer phase interphase. Results have also been confirmed by SEM, while the degree of adhesion and the interpenetration of polymer phase / woven flax fiber are superior in the case of composites made of functionalized flax fibers in comparison with the unfunctionalized ones
Magnetite nanoparticles for functionalized textile dressing to prevent fungal biofilms development
The purpose of this work was to investigate the potential of functionalized magnetite nanoparticles to improve the antibiofilm properties of textile dressing, tested in vitro against monospecific Candida albicans biofilms. Functionalized magnetite (Fe(3)O(4)/C(18)), with an average size not exceeding 20 nm, has been synthesized by precipitation of ferric and ferrous salts in aqueous solution of oleic acid (C(18)) and NaOH. Transmission electron microscopy, X-ray diffraction analysis, and differential thermal analysis coupled with thermo gravimetric analysis were used as characterization methods for the synthesized Fe(3)O(4)/C(18). Scanning electron microscopy was used to study the architecture of the fungal biofilm developed on the functionalized textile dressing samples and culture-based methods for the quantitative assay of the biofilm-embedded yeast cells. The optimized textile dressing samples proved to be more resistant to C. albicans colonization, as compared to the uncoated ones; these functionalized surfaces-based approaches are very useful in the prevention of wound microbial contamination and subsequent biofilm development on viable tissues or implanted devices
Bone tissue regeneration using different 3D matrices
Introduction. There are several types of grafts used in the treatment of bone defects [1]. During the
research, was tested the regeneration capacity of critical bone defects with several types of materials.
Materials and methods. To 18 New Zealand rabbits, under general anesthesia in both parietal bones,
8 mm in diameter critical defects were made. In the defects made in the right parietal bones were
transplanted (n=3): collagen sponges cross-linked with 25% glutaraldehyde (GA) vapours, collagen
sponges cross-linked with 25 mM riboflavin under UV-A [3], lamellas of demineralised bone matrix
(DBM), shredded DBM [2], and 3D printed PLA discs; the control materials were transplanted in
defects made in the left parietal bones: minced autologous iliac bone and Colapan. The rabbits were
removed from the experiment at 12 weeks, the calvarias were fixed in 10% buffered formaldehyde.
The regenerated defects were examined histologically by Hematoxylin-Eosin staining, and scanning
electron microscopy (SEM) [4].
Results. The histological examination of defects treated with minced autologous bone showed an
inflammatory process with necrosis and resorption of transplanted bone trabeculae. In defects treated
with Colapan formation of bone trabeculae in the areas of contact with the native bone was
determined. The defects treated with cross-linked collagen sponges showed a dense and regularly
distributed collagen fibers when using GA and degenerated, loose with thin fibrillar structure for
riboflavin. When DBM lamellas were used, debris of DBM matrix and disorganized fibrous
connective tissue with an infiltrative character were found. The shredded DBM fragments were
consolidated with fibrous tissue and at the periphery of the fragments, trabecular extensions of newly
formed bone were determined. In spaces between filaments of PLA discs were found thick collagen
fibers forming bundles and newly formed trabeculae of reticular fibrous bone. SEM showed that
transplanted materials changed significant their structure except the PLA discs.
Conclusions. The difference between the obtained results showed that not all materials can be used
for an efficient regeneration of critical bone tissue defects. Compared to the control and the other
experimental groups, shredded DBM at 12 weeks filled the defect with bone-like tissue
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