The iron oxide nanoparticles were synthetized by an adapted coprecpitation method. Stuctural and ... more The iron oxide nanoparticles were synthetized by an adapted coprecpitation method. Stuctural and morphological characterization of the obtained iron oxide nanoparticles were investigated by X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). Furthermore, in vitro and in vivo studies were investigated by cell viability assay and HeLa cells. For the analysis of iron oxide toxicity in vivo, several mice were treated with normal saline and iron oxide via intraperitoneal injection (IP). The XRD spectra showed the peaks associated to the spinel cubic lattice type with the lattice of 0.835 nm. By magnified TEM image, it could be observed that the samples have a uniform morphology with relatively spherical shape and nanometric size. Moreover, inverted fluorescence microscopy images of HeLa cells with normal phenotype and HeLa cells treated for 72 hourswith a suspension of γ-Fe 2 O 3 nanoparticles revealed the non-toxic character. The histophtological studies have demonstrated that at 72 hours after IP administration, the iron oxide nanoparticles are not accumulating in kidney and spleen, thus establishing their utility as drug delivery systems targeted to these organs.
Annals. Series on Physics and Chemistry, Mar 15, 2024
Magnetite is an iron oxide that has been extensively investigated for its utilization in the deve... more Magnetite is an iron oxide that has been extensively investigated for its utilization in the development of drug delivery nanocarriers. Generally, magnetite nanoparticles are obtained through the chemical route of co-precipitation. However, since the outcome properties of the resulted nanoparticles are limited in terms of possibility to control the size and size distribution and to ensure the reproducibility of the synthesis process, unconventional synthesis routes are constantly investigated. Specifically, the microwave-assisted hydrothermal method represents an alternative with tremendous potential owing to the possibility of varying the treatment parameters, i.e., pressure, temperature, time. Thus, the present study aimed to investigate the influence of time and temperature upon the structural and physico-chemical properties of magnetite nanoparticles.
World Academy of Science, Engineering and Technology, International Journal of Biomedical and Biological Engineering, May 18, 2015
We prepared graphene (GR)-cobalt phthalocyanine (CoPc) and GR-iron phthalocyanine (FePc) composit... more We prepared graphene (GR)-cobalt phthalocyanine (CoPc) and GR-iron phthalocyanine (FePc) composites by simple and facile chemical reduction method for enzymatic fuel cell (EFC) applications. The successful formation of the composites was confirmed by scanning electron microscopy (SEM), Energydispersive X-ray spectroscopy (EDX), X-ray diffraction and electrochemical methods. The as-prepared composites were used for the construction of glucose/O 2 EFC. The anode of the EFC was prepared by immobilizing glucose oxidase (GOx) at the GR-CoPc composite modified glassy carbon electrode (GCE). GCE/GR-CoPc/GOx exhibited excellent electrocatalytic ability towards oxidation of glucose. In addition, the modified electrode showed appreciable stability, repeatability and reproducibility. GR-FePc composite exhibited superior electrocatalytic ability towards oxygen reduction reaction (ORR). A membraneless glucose/O 2 EFC has been fabricated employing GCE/GR-CoPc/GOx and GCE/GR-FePc as anode and cathode respectively. The fabricated EFC offered a maximum power density of 23 mW cm À2 which is comparable with the previously reported EFCs and it exhibited appreciable stability and repeatability. From this study, we infer that GR based MPcs have great potential for the fabrication of EFCs.
International Journal of Molecular Sciences, Mar 16, 2023
In this paper, we report the synthesis of ZnO nanoparticles (NPs) by forced solvolysis of Zn(CH 3... more In this paper, we report the synthesis of ZnO nanoparticles (NPs) by forced solvolysis of Zn(CH 3 COO) 2 •2H 2 O in alcohols with a different number of -OH groups. We study the influence of alcohol type (n-butanol, ethylene glycol and glycerin) on the size, morphology, and properties of the obtained ZnO NPs. The smallest polyhedral ZnO NPs (<30 nm) were obtained in n-butanol, while in ethylene glycol the NPs measured on average 44 nm and were rounded. Polycrystalline particles of 120 nm were obtained in glycerin only after water refluxing. In addition, here, we report the photocatalytic activity, against a dye mixture, of three model pollutants: methyl orange (MO), methylene blue (MB), and rhodamine B (RhB), a model closer to real situations where water is polluted with many chemicals. All samples exhibited good photocatalytic activity against the dye mixture, with degradation efficiency reaching 99.99%. The sample with smallest nanoparticles maintained a high efficiency >90%, over five catalytic cycles. Antibacterial tests were conducted against Gram-negative strains Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa, and Escherichia coli, and Gram-positive strains Enterococcus faecalis, Bacillus subtilis, Staphylococcus aureus, and Bacillus cereus. The ZnO samples presented strong inhibition of planktonic growth for all tested strains, indicating that they can be used for antibacterial applications, such as water purification.
Materialele obţinute au fost caracterizate prin, FTIR şi XRD precum şi din punct de vedere a capa... more Materialele obţinute au fost caracterizate prin, FTIR şi XRD precum şi din punct de vedere a capacităţii de eliberare a acidului folic şi absorbţiei de apă. Se poate concluziona că viteza de eliberare este influenţată de tipul precursorilor de silice utilizaţi.
This chapter is devoted to the advances in the field of nanoparticles-mediated cancer treatment. ... more 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 Fe 3 O 4 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 nanoparticlesmagnetite, 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.
As it is used in all aspects of human life, water has become more and more polluted. For the past... more As it is used in all aspects of human life, water has become more and more polluted. For the past few decades, researchers and scientists have focused on developing innovative composite adsorbent membranes for water purification. The purpose of this research was to synthesize a novel composite adsorbent membrane for the removal of toxic pollutants (namely heavy metals, antibiotics and microorganisms). The as-synthesized chitosan/TiO 2 composite membranes were successfully prepared through a simple casting method. The TiO 2 nanoparticle concentration from the composite membranes was kept low, at 1% and 5%, in order not to block the functional groups of chitosan, which are responsible for the adsorption of metal ions. Nevertheless, the concentration of TiO 2 must be high enough to bestow good photocatalytic and antimicrobial activities. The synthesized composite membranes were characterized by Fourier transform infrared spectroscopy (FTIR), Xray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and swelling capacity. The antibacterial activity was determined against four strains, Escherichia coli, Citrobacter spp., Enterococcus faecalis and Staphylococcus aureus. For the Gram-negative strains, a reduction of more than 5 units log CFU/mL was obtained. The adsorption capacity for heavy metal ions was maximum for the chitosan/TiO 2 1% composite membrane, the retention values being 297 mg/g for Pb 2+ and 315 mg/g for Cd 2+ ions. These values were higher for the chitosan/TiO 2 1% than for chitosan/TiO 2 5%, indicating that a high content of TiO 2 can be one of the reasons for modest results reported previously in the literature. The photocatalytic degradation of a five-antibiotic mixture led to removal efficiencies of over 98% for tetracycline and meropenem, while for vancomycin and erythromycin the efficiencies were 86% and 88%, respectively. These values indicate that the chitosan/TiO 2 composite membranes exhibit excellent photocatalytic activity under visible light irradiation. The obtained composite membranes can be used for complex water purification processes (removal of heavy metal ions, antibiotics and microorganisms).
Zinc oxide (ZnO) nanomaterials are used in various health-related applications, from antimicrobia... more Zinc oxide (ZnO) nanomaterials are used in various health-related applications, from antimicrobial textiles to wound dressing composites and from sunscreens to antimicrobial packaging. Purity, surface defects, size, and morphology of the nanoparticles are the main factors that influence the antimicrobial properties. In this study, we are comparing the properties of the ZnO nanoparticles obtained by solvolysis using a series of alcohols: primary from methanol to 1-hexanol, secondary (2-propanol and 2-butanol), and tertiary (tert-butanol). While the synthesis of ZnO nanoparticles is successfully accomplished in all primary alcohols, the use of secondary or tertiary alcohols does not lead to ZnO as final product, underlining the importance of the used solvent. The shape of the obtained nanoparticles depends on the alcohol used, from quasi-spherical to rods, and consequently, different properties are reported, including photocatalytic and antimicrobial activities. In the photocatalytic study, the ZnO obtained in 1-butanol exhibited the best performance against methylene blue (MB) dye solution, attaining a degradation efficiency of 98.24%. The comparative study among a series of usual model dyes revealed that triarylmethane dyes are less susceptible to photo-degradation. The obtained ZnO nanoparticles present a strong antimicrobial activity on a broad range of microorganisms (bacterial and fungal strains), the size and shape being the important factors. This permits further tailoring for use in medical applications.
Hydrogels have been widely used as drug delivery systems for scaffold production (in different so... more Hydrogels have been widely used as drug delivery systems for scaffold production (in different soft and hard tissue engineering, including bones), thanks to their biocompatibility and biodegradability. In addition to the possibility of synthesizing a wide range of hydrogels from various natural and synthetic polymers, they are suitable for scaffold production. Moreover, they can have antimicrobial, antitumor and analgesic functions due to their intrinsic properties or through addition of proper biologically active agents. In this article, different types of hydrogels are reviewed alongside their application areas. Different methods are applied for the preparation of hydrogels and their compositions, and are strongly correlated with the morphological and mechanical properties of the synthesized hydrogels, which had a great influence on the performances of the respective scaffolds. The most effective ways to produce the desired scaffolds are mold casting, especially, 3D printing and electrospinning due to the ability to manipulate and control the shape and size of the desired scaffold as well as their microstructure.
Romanian Journal of Morphology and Embryology, Jun 25, 2021
The beneficial synergy between antimicrobial silver nanoparticles (AgNPs) and essential oils (EOs... more The beneficial synergy between antimicrobial silver nanoparticles (AgNPs) and essential oils (EOs), with therapeutic effects that have been acknowledged and explored for a long time, opens the way towards developing new and promising alternatives for anti-infective therapies. With the aim to improve the cytocompatibility and stability of AgNPs and to overcome the volatilization of EOs, AgNPs conjugated with sage (Salvia officinalis) and cinnamon (Cinnamomum aromaticum) EOs were obtained in our study. The synthesis process was realized either by classical or ultrasound-assisted chemical reduction. Compositional and microstructural characterization of the as-obtained Ag@EO NPs was performed by X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The biodistribution of Ag@EO NPs was evaluated on a mouse animal model.
Bone tissue engineering has attracted great interest in the last few years, as the frequency of t... more Bone tissue engineering has attracted great interest in the last few years, as the frequency of tissue-damaging or degenerative diseases has increased exponentially. To obtain an ideal treatment solution, researchers have focused on the development of optimum biomaterials to be applied for the enhancement of bioactivity and the regeneration process, which are necessary to support the proper healing process of osseous tissues. In this regard, hydroxyapatite (HA) has been the most widely used material in the biomedical field due to its great biocompatibility and similarity with the native apatite from the human bone. However, HA still presents some deficiencies related to its mechanical properties, which are essential for HA to be applied in load-bearing applications. Bioactivity is another vital property of HA and is necessary to further improve regeneration and antibacterial activity. These drawbacks can be solved by doping the material with trace elements, adapting the properties o...
The highest amount of the world’s polyethylene terephthalate (PET) is designated for fiber produc... more The highest amount of the world’s polyethylene terephthalate (PET) is designated for fiber production (more than 60%) and food packaging (30%) and it is one of the major polluting polymers. Although there is a great interest in recycling PET-based materials, a large amount of unrecycled material is derived mostly from the food and textile industries. The aim of this study was to obtain and characterize nanostructured membranes with fibrillar consistency based on recycled PET and nanoparticles (Fe3O4@UA) using the electrospinning technique. The obtained fibers limit microbial colonization and the development of biofilms. Such fibers could significantly impact modern food packaging and the design of improved textile fibers with antimicrobial effects and good biocompatibility. In conclusion, this study suggests an alternative for PET recycling and further applies it in the development of antimicrobial biomaterials.
The recognized antimicrobial activity of silver nanoparticles is a well-studied property, especia... more The recognized antimicrobial activity of silver nanoparticles is a well-studied property, especially when designing and developing biomaterials with medical applications. As biological activity is closely related to the physicochemical characteristics of a material, aspects such as particle morphology and dimension should be considered. Microfluidic systems in continuous flow represent a promising method to control the size, shape, and size distribution of synthesized nanoparticles. Moreover, using microfluidics widens the synthesis options by creating and controlling parameters that are otherwise difficult to maintain in conventional batch procedures. This study used a microfluidic platform with a cross-shape design as an innovative method for synthesizing silver nanoparticles and varied the precursor concentration and the purging speed as experimental parameters. The compositional and microstructural characterization of the obtained samples was carried out by X-ray diffraction (XR...
The production of highly porous and three-dimensional (3D) scaffolds with biomimicking abilities ... more The production of highly porous and three-dimensional (3D) scaffolds with biomimicking abilities has gained extensive attention in recent years for tissue engineering (TE) applications. Considering the attractive and versatile biomedical functionality of silica (SiO2) nanomaterials, we propose herein the development and validation of SiO2-based 3D scaffolds for TE. This is the first report on the development of fibrous silica architectures, using tetraethyl orthosilicate (TEOS) and polyvinyl alcohol (PVA) during the self-assembly electrospinning (ES) processing (a layer of flat fibers must first be created in self-assembly electrospinning before fiber stacks can develop on the fiber mat). The compositional and microstructural characteristics of obtained fibrous materials were evaluated by complementary techniques, in both the pre-ES aging period and post-ES calcination. Then, in vivo evaluation confirmed their possible use as bioactive scaffolds in bone TE.
Honey has been used for therapeutic and nutritional purposes since ancient times. It was consider... more Honey has been used for therapeutic and nutritional purposes since ancient times. It was considered one of the essential medical assets in wound healing. According to research, honeybees have significant antibacterial, antioxidant, anti-inflammatory, antitumor, and wound-healing properties. Lately, scientific researchers have focused on apitherapy, using bee products to protect and strengthen the immune system. Since honey is the most important natural product rich in minerals, proteins, and vitamins, it has been intensively used in such therapies. Honey has gained significant consideration because of the beneficial role of its antioxidant compounds, such as enzymes, proteins, amino and organic acids, polyphenols, and carotenoids, but mainly due to flavonoids and phenolic acids. It has been proven that phenolic compounds are responsible for honey’s biological activity and that its physicochemical properties, antioxidants, and antimicrobial potential are significant for human health....
Iron oxide nanoparticles (IONPs) have been extensively used in different biomedical applications ... more Iron oxide nanoparticles (IONPs) have been extensively used in different biomedical applications due to their biocompatibility and magnetic properties. However, different functionalization approaches have been developed to improve their time-life in the systemic circulation. Here, we have synthesized IONPs using a modified Massart method and functionalized them in situ with polyethylene glycol with different molecular weights (20 K and 35 K). The resulting nanoparticles were characterized in terms of morphology, structure, and composition using transmission electron microscopy (TEM) and selected area electron diffraction (SAED). In vivo biodistribution was evaluated in Balb/c mice, the presence of IONP being evidenced through histopathological investigations. IONP morphological characterization showed a change in shape (from spherical to rhombic) and size with molecular weight, while structural characterization proved the obtaining of highly crystalline samples of spinel structured ...
Microelectromechanical systems (MEMS) have been increasingly used worldwide in a wide range of ap... more Microelectromechanical systems (MEMS) have been increasingly used worldwide in a wide range of applications, including high tech, energy, medicine or environmental applications. Magnetic polymer composite films have been used extensively in the development of the micropumps and valves, which are critical components of the microelectromechanical systems. Based on the literature survey, several polymers and magnetic micro and nanopowders can be identified and, depending on their nature, ratio, processing route and the design of the device, their performances can be tuned from simple valves and pumps to biomimetic devices, such as, for instance, hearth ventricles. In many such devices, polymer magnetic films are used, the disposal of the magnetic component being either embedded into the polymer or coated on the polymer. One or more actuation zones can be used and the flow rate can be mono-directional or bi-directional depending on the design. In this paper, we review the main advances ...
The iron oxide nanoparticles were synthetized by an adapted coprecpitation method. Stuctural and ... more The iron oxide nanoparticles were synthetized by an adapted coprecpitation method. Stuctural and morphological characterization of the obtained iron oxide nanoparticles were investigated by X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). Furthermore, in vitro and in vivo studies were investigated by cell viability assay and HeLa cells. For the analysis of iron oxide toxicity in vivo, several mice were treated with normal saline and iron oxide via intraperitoneal injection (IP). The XRD spectra showed the peaks associated to the spinel cubic lattice type with the lattice of 0.835 nm. By magnified TEM image, it could be observed that the samples have a uniform morphology with relatively spherical shape and nanometric size. Moreover, inverted fluorescence microscopy images of HeLa cells with normal phenotype and HeLa cells treated for 72 hourswith a suspension of γ-Fe 2 O 3 nanoparticles revealed the non-toxic character. The histophtological studies have demonstrated that at 72 hours after IP administration, the iron oxide nanoparticles are not accumulating in kidney and spleen, thus establishing their utility as drug delivery systems targeted to these organs.
Annals. Series on Physics and Chemistry, Mar 15, 2024
Magnetite is an iron oxide that has been extensively investigated for its utilization in the deve... more Magnetite is an iron oxide that has been extensively investigated for its utilization in the development of drug delivery nanocarriers. Generally, magnetite nanoparticles are obtained through the chemical route of co-precipitation. However, since the outcome properties of the resulted nanoparticles are limited in terms of possibility to control the size and size distribution and to ensure the reproducibility of the synthesis process, unconventional synthesis routes are constantly investigated. Specifically, the microwave-assisted hydrothermal method represents an alternative with tremendous potential owing to the possibility of varying the treatment parameters, i.e., pressure, temperature, time. Thus, the present study aimed to investigate the influence of time and temperature upon the structural and physico-chemical properties of magnetite nanoparticles.
World Academy of Science, Engineering and Technology, International Journal of Biomedical and Biological Engineering, May 18, 2015
We prepared graphene (GR)-cobalt phthalocyanine (CoPc) and GR-iron phthalocyanine (FePc) composit... more We prepared graphene (GR)-cobalt phthalocyanine (CoPc) and GR-iron phthalocyanine (FePc) composites by simple and facile chemical reduction method for enzymatic fuel cell (EFC) applications. The successful formation of the composites was confirmed by scanning electron microscopy (SEM), Energydispersive X-ray spectroscopy (EDX), X-ray diffraction and electrochemical methods. The as-prepared composites were used for the construction of glucose/O 2 EFC. The anode of the EFC was prepared by immobilizing glucose oxidase (GOx) at the GR-CoPc composite modified glassy carbon electrode (GCE). GCE/GR-CoPc/GOx exhibited excellent electrocatalytic ability towards oxidation of glucose. In addition, the modified electrode showed appreciable stability, repeatability and reproducibility. GR-FePc composite exhibited superior electrocatalytic ability towards oxygen reduction reaction (ORR). A membraneless glucose/O 2 EFC has been fabricated employing GCE/GR-CoPc/GOx and GCE/GR-FePc as anode and cathode respectively. The fabricated EFC offered a maximum power density of 23 mW cm À2 which is comparable with the previously reported EFCs and it exhibited appreciable stability and repeatability. From this study, we infer that GR based MPcs have great potential for the fabrication of EFCs.
International Journal of Molecular Sciences, Mar 16, 2023
In this paper, we report the synthesis of ZnO nanoparticles (NPs) by forced solvolysis of Zn(CH 3... more In this paper, we report the synthesis of ZnO nanoparticles (NPs) by forced solvolysis of Zn(CH 3 COO) 2 •2H 2 O in alcohols with a different number of -OH groups. We study the influence of alcohol type (n-butanol, ethylene glycol and glycerin) on the size, morphology, and properties of the obtained ZnO NPs. The smallest polyhedral ZnO NPs (<30 nm) were obtained in n-butanol, while in ethylene glycol the NPs measured on average 44 nm and were rounded. Polycrystalline particles of 120 nm were obtained in glycerin only after water refluxing. In addition, here, we report the photocatalytic activity, against a dye mixture, of three model pollutants: methyl orange (MO), methylene blue (MB), and rhodamine B (RhB), a model closer to real situations where water is polluted with many chemicals. All samples exhibited good photocatalytic activity against the dye mixture, with degradation efficiency reaching 99.99%. The sample with smallest nanoparticles maintained a high efficiency >90%, over five catalytic cycles. Antibacterial tests were conducted against Gram-negative strains Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa, and Escherichia coli, and Gram-positive strains Enterococcus faecalis, Bacillus subtilis, Staphylococcus aureus, and Bacillus cereus. The ZnO samples presented strong inhibition of planktonic growth for all tested strains, indicating that they can be used for antibacterial applications, such as water purification.
Materialele obţinute au fost caracterizate prin, FTIR şi XRD precum şi din punct de vedere a capa... more Materialele obţinute au fost caracterizate prin, FTIR şi XRD precum şi din punct de vedere a capacităţii de eliberare a acidului folic şi absorbţiei de apă. Se poate concluziona că viteza de eliberare este influenţată de tipul precursorilor de silice utilizaţi.
This chapter is devoted to the advances in the field of nanoparticles-mediated cancer treatment. ... more 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 Fe 3 O 4 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 nanoparticlesmagnetite, 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.
As it is used in all aspects of human life, water has become more and more polluted. For the past... more As it is used in all aspects of human life, water has become more and more polluted. For the past few decades, researchers and scientists have focused on developing innovative composite adsorbent membranes for water purification. The purpose of this research was to synthesize a novel composite adsorbent membrane for the removal of toxic pollutants (namely heavy metals, antibiotics and microorganisms). The as-synthesized chitosan/TiO 2 composite membranes were successfully prepared through a simple casting method. The TiO 2 nanoparticle concentration from the composite membranes was kept low, at 1% and 5%, in order not to block the functional groups of chitosan, which are responsible for the adsorption of metal ions. Nevertheless, the concentration of TiO 2 must be high enough to bestow good photocatalytic and antimicrobial activities. The synthesized composite membranes were characterized by Fourier transform infrared spectroscopy (FTIR), Xray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and swelling capacity. The antibacterial activity was determined against four strains, Escherichia coli, Citrobacter spp., Enterococcus faecalis and Staphylococcus aureus. For the Gram-negative strains, a reduction of more than 5 units log CFU/mL was obtained. The adsorption capacity for heavy metal ions was maximum for the chitosan/TiO 2 1% composite membrane, the retention values being 297 mg/g for Pb 2+ and 315 mg/g for Cd 2+ ions. These values were higher for the chitosan/TiO 2 1% than for chitosan/TiO 2 5%, indicating that a high content of TiO 2 can be one of the reasons for modest results reported previously in the literature. The photocatalytic degradation of a five-antibiotic mixture led to removal efficiencies of over 98% for tetracycline and meropenem, while for vancomycin and erythromycin the efficiencies were 86% and 88%, respectively. These values indicate that the chitosan/TiO 2 composite membranes exhibit excellent photocatalytic activity under visible light irradiation. The obtained composite membranes can be used for complex water purification processes (removal of heavy metal ions, antibiotics and microorganisms).
Zinc oxide (ZnO) nanomaterials are used in various health-related applications, from antimicrobia... more Zinc oxide (ZnO) nanomaterials are used in various health-related applications, from antimicrobial textiles to wound dressing composites and from sunscreens to antimicrobial packaging. Purity, surface defects, size, and morphology of the nanoparticles are the main factors that influence the antimicrobial properties. In this study, we are comparing the properties of the ZnO nanoparticles obtained by solvolysis using a series of alcohols: primary from methanol to 1-hexanol, secondary (2-propanol and 2-butanol), and tertiary (tert-butanol). While the synthesis of ZnO nanoparticles is successfully accomplished in all primary alcohols, the use of secondary or tertiary alcohols does not lead to ZnO as final product, underlining the importance of the used solvent. The shape of the obtained nanoparticles depends on the alcohol used, from quasi-spherical to rods, and consequently, different properties are reported, including photocatalytic and antimicrobial activities. In the photocatalytic study, the ZnO obtained in 1-butanol exhibited the best performance against methylene blue (MB) dye solution, attaining a degradation efficiency of 98.24%. The comparative study among a series of usual model dyes revealed that triarylmethane dyes are less susceptible to photo-degradation. The obtained ZnO nanoparticles present a strong antimicrobial activity on a broad range of microorganisms (bacterial and fungal strains), the size and shape being the important factors. This permits further tailoring for use in medical applications.
Hydrogels have been widely used as drug delivery systems for scaffold production (in different so... more Hydrogels have been widely used as drug delivery systems for scaffold production (in different soft and hard tissue engineering, including bones), thanks to their biocompatibility and biodegradability. In addition to the possibility of synthesizing a wide range of hydrogels from various natural and synthetic polymers, they are suitable for scaffold production. Moreover, they can have antimicrobial, antitumor and analgesic functions due to their intrinsic properties or through addition of proper biologically active agents. In this article, different types of hydrogels are reviewed alongside their application areas. Different methods are applied for the preparation of hydrogels and their compositions, and are strongly correlated with the morphological and mechanical properties of the synthesized hydrogels, which had a great influence on the performances of the respective scaffolds. The most effective ways to produce the desired scaffolds are mold casting, especially, 3D printing and electrospinning due to the ability to manipulate and control the shape and size of the desired scaffold as well as their microstructure.
Romanian Journal of Morphology and Embryology, Jun 25, 2021
The beneficial synergy between antimicrobial silver nanoparticles (AgNPs) and essential oils (EOs... more The beneficial synergy between antimicrobial silver nanoparticles (AgNPs) and essential oils (EOs), with therapeutic effects that have been acknowledged and explored for a long time, opens the way towards developing new and promising alternatives for anti-infective therapies. With the aim to improve the cytocompatibility and stability of AgNPs and to overcome the volatilization of EOs, AgNPs conjugated with sage (Salvia officinalis) and cinnamon (Cinnamomum aromaticum) EOs were obtained in our study. The synthesis process was realized either by classical or ultrasound-assisted chemical reduction. Compositional and microstructural characterization of the as-obtained Ag@EO NPs was performed by X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The biodistribution of Ag@EO NPs was evaluated on a mouse animal model.
Bone tissue engineering has attracted great interest in the last few years, as the frequency of t... more Bone tissue engineering has attracted great interest in the last few years, as the frequency of tissue-damaging or degenerative diseases has increased exponentially. To obtain an ideal treatment solution, researchers have focused on the development of optimum biomaterials to be applied for the enhancement of bioactivity and the regeneration process, which are necessary to support the proper healing process of osseous tissues. In this regard, hydroxyapatite (HA) has been the most widely used material in the biomedical field due to its great biocompatibility and similarity with the native apatite from the human bone. However, HA still presents some deficiencies related to its mechanical properties, which are essential for HA to be applied in load-bearing applications. Bioactivity is another vital property of HA and is necessary to further improve regeneration and antibacterial activity. These drawbacks can be solved by doping the material with trace elements, adapting the properties o...
The highest amount of the world’s polyethylene terephthalate (PET) is designated for fiber produc... more The highest amount of the world’s polyethylene terephthalate (PET) is designated for fiber production (more than 60%) and food packaging (30%) and it is one of the major polluting polymers. Although there is a great interest in recycling PET-based materials, a large amount of unrecycled material is derived mostly from the food and textile industries. The aim of this study was to obtain and characterize nanostructured membranes with fibrillar consistency based on recycled PET and nanoparticles (Fe3O4@UA) using the electrospinning technique. The obtained fibers limit microbial colonization and the development of biofilms. Such fibers could significantly impact modern food packaging and the design of improved textile fibers with antimicrobial effects and good biocompatibility. In conclusion, this study suggests an alternative for PET recycling and further applies it in the development of antimicrobial biomaterials.
The recognized antimicrobial activity of silver nanoparticles is a well-studied property, especia... more The recognized antimicrobial activity of silver nanoparticles is a well-studied property, especially when designing and developing biomaterials with medical applications. As biological activity is closely related to the physicochemical characteristics of a material, aspects such as particle morphology and dimension should be considered. Microfluidic systems in continuous flow represent a promising method to control the size, shape, and size distribution of synthesized nanoparticles. Moreover, using microfluidics widens the synthesis options by creating and controlling parameters that are otherwise difficult to maintain in conventional batch procedures. This study used a microfluidic platform with a cross-shape design as an innovative method for synthesizing silver nanoparticles and varied the precursor concentration and the purging speed as experimental parameters. The compositional and microstructural characterization of the obtained samples was carried out by X-ray diffraction (XR...
The production of highly porous and three-dimensional (3D) scaffolds with biomimicking abilities ... more The production of highly porous and three-dimensional (3D) scaffolds with biomimicking abilities has gained extensive attention in recent years for tissue engineering (TE) applications. Considering the attractive and versatile biomedical functionality of silica (SiO2) nanomaterials, we propose herein the development and validation of SiO2-based 3D scaffolds for TE. This is the first report on the development of fibrous silica architectures, using tetraethyl orthosilicate (TEOS) and polyvinyl alcohol (PVA) during the self-assembly electrospinning (ES) processing (a layer of flat fibers must first be created in self-assembly electrospinning before fiber stacks can develop on the fiber mat). The compositional and microstructural characteristics of obtained fibrous materials were evaluated by complementary techniques, in both the pre-ES aging period and post-ES calcination. Then, in vivo evaluation confirmed their possible use as bioactive scaffolds in bone TE.
Honey has been used for therapeutic and nutritional purposes since ancient times. It was consider... more Honey has been used for therapeutic and nutritional purposes since ancient times. It was considered one of the essential medical assets in wound healing. According to research, honeybees have significant antibacterial, antioxidant, anti-inflammatory, antitumor, and wound-healing properties. Lately, scientific researchers have focused on apitherapy, using bee products to protect and strengthen the immune system. Since honey is the most important natural product rich in minerals, proteins, and vitamins, it has been intensively used in such therapies. Honey has gained significant consideration because of the beneficial role of its antioxidant compounds, such as enzymes, proteins, amino and organic acids, polyphenols, and carotenoids, but mainly due to flavonoids and phenolic acids. It has been proven that phenolic compounds are responsible for honey’s biological activity and that its physicochemical properties, antioxidants, and antimicrobial potential are significant for human health....
Iron oxide nanoparticles (IONPs) have been extensively used in different biomedical applications ... more Iron oxide nanoparticles (IONPs) have been extensively used in different biomedical applications due to their biocompatibility and magnetic properties. However, different functionalization approaches have been developed to improve their time-life in the systemic circulation. Here, we have synthesized IONPs using a modified Massart method and functionalized them in situ with polyethylene glycol with different molecular weights (20 K and 35 K). The resulting nanoparticles were characterized in terms of morphology, structure, and composition using transmission electron microscopy (TEM) and selected area electron diffraction (SAED). In vivo biodistribution was evaluated in Balb/c mice, the presence of IONP being evidenced through histopathological investigations. IONP morphological characterization showed a change in shape (from spherical to rhombic) and size with molecular weight, while structural characterization proved the obtaining of highly crystalline samples of spinel structured ...
Microelectromechanical systems (MEMS) have been increasingly used worldwide in a wide range of ap... more Microelectromechanical systems (MEMS) have been increasingly used worldwide in a wide range of applications, including high tech, energy, medicine or environmental applications. Magnetic polymer composite films have been used extensively in the development of the micropumps and valves, which are critical components of the microelectromechanical systems. Based on the literature survey, several polymers and magnetic micro and nanopowders can be identified and, depending on their nature, ratio, processing route and the design of the device, their performances can be tuned from simple valves and pumps to biomimetic devices, such as, for instance, hearth ventricles. In many such devices, polymer magnetic films are used, the disposal of the magnetic component being either embedded into the polymer or coated on the polymer. One or more actuation zones can be used and the flow rate can be mono-directional or bi-directional depending on the design. In this paper, we review the main advances ...
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Papers by Ecaterina Andronescu