Abstract Core–shell nanoparticles (NPs) are progressively attracting more attention, since the af... more Abstract Core–shell nanoparticles (NPs) are progressively attracting more attention, since the aforementioned NPs have arisen at the border between applied materials chemistry and nanotechnology. The particles display distinctive properties of the diverse materials combined. This is particularly true in terms of the inherent ability to influence the surface functions to meet the varied application needs. Nanomaterials possess well-known antimicrobial activity against several microorganisms and have been thoroughly investigated in terms of cancer research. A lot of antimicrobial nanostructures, such as zinc oxide, silver, gold, and iron oxide NPs, have been technologically engineered recently in order to kill or prevent the growth of pathogenic microbes. Even though there has been a lot of improvement in the understanding of cancer, this condition is still a main leading cause of mortality and morbidity. Because of the several disadvantages of conventional treatments, such as severe side effects and lack of specificity, core–shell NPs–based therapies have been intensely investigated over the last several years. Therapies such as hyperthermia, targeted drug delivery, and a combination of radiotherapy and photothermal therapy are still under research and show promising results when aided by core–shell NPs. Given the versatility in the synthesis of these NPs, numerous types of materials can be used in order to manufacture core–shell nanosystems that are biocompatible and have specific properties, depending on the applications in which they are used.
Considering the large number of the multiresistant bacterial strains and the increasing need in n... more Considering the large number of the multiresistant bacterial strains and the increasing need in new antimicrobial formulation, the aim of this study was to evaluate the antipathogenic effect of E. caryophyllata essential oil on collection and recently isolated clinical strains of P. aeruginosa and S. aureus. Experimental assays were carried out by in vitro and in vivo tests. Qualitative and quantitative assessment of the antimicrobial activity was followed by the analysis of the essential oil influence on enzymatic soluble virulence factors expression. The cytotoxic effect of the vegetal extract was quantified by using HeLa cells. Nanosystem embedded essential oil was used to establish the in vivo antipathogenic effect on mice. Qualitative screening results revealed an early microbicidal effect quantified by low minimum inhibitory concentration values. The in vivo study showed a stabiliziation of the essential oil biological activities when using nanosystem embedding, that could be ...
Despite the recent biomedical advances in diagnosis and therapy, cartilage and muscle disorders r... more Despite the recent biomedical advances in diagnosis and therapy, cartilage and muscle disorders represent debilitating conditions with massive economical, social and clinical impacts. Severe complications of such difficult-to-treat or untreatable diseases limit current therapeutic approaches and lead to the acute need for development of novel therapeutic or reparatory strategies. Current research is increasingly focused on finding or obtaining suitable materials with specific biomedical traits to be used as competitive candidates in the engineering of new tissues and organs to replace or heal damaged tissues. The purpose of this study is to present the most prevalent cartilage- and muscular-tissue-related diseases and highlight the recent scientific progress regarding the development of classical and recent therapeutic approaches, focusing on discussing the impact and advantages of bioactive nanomaterials in designing functional scaffolds for cartilage and muscle repair.
Nanotherapeutics have received an increased attention in the recent years especially because of t... more Nanotherapeutics have received an increased attention in the recent years especially because of their impact in medicine, being successfully utilized as antimicrobial agents, targeted drug delivery systems, anticancer drugs, and so on. In this chapter, we aimed to make an updated screening of the main inorganic and organic nanosystems with antimicrobial and antitumor properties, which are the most inciting and investigated approaches in nanotherapy. We also discussed the main issues regarding their clinical use, properties of these systems, driving mechanism, and highlighted their advantages and disadvantages for modern therapy.
Received: 10.01.2013 This study reports the effect of some essential oils (EOs) and of some of th... more Received: 10.01.2013 This study reports the effect of some essential oils (EOs) and of some of their major fractions on soluble virulence factors and quorum sensing (QS) gene expression profiles of 15 Staphylococcus aureus and Pseudomonas aeruginosa clinical strains. EOs were extracted from various angiosperm and gymnosperm vegetal taxons by hydrodistillation in a Neo-Clevengertype apparatus and characterized by measuring the density and refractive index, as well as by gas chromatographic analysis. EOs and their major components proved to inhibit the phenotypic expression of six soluble virulence determinants (haemolysins, gelatinase, DN-ase, lipase, amylase, esculin hydrolysis) when used in sub-inhibitory concentrations, in both P. aeruginosa and S. aureus strains. EOs extracted from Salvia officinalis, Rosmarinus officinalis, Abies alba and Eugenia caryophyllata as well as some of their major compounds (limonene, eugenol and eucalyptol) inhibited QS genes expression in S. aureus, ...
Chronic infections represent an important burden on the healthcare system and have a significant ... more Chronic infections represent an important burden on the healthcare system and have a significant impact on the patients’ quality of life. While Staphylococcus spp. are commensal bacteria, they can become pathogenic, leading to various types of infections. In this study we aimed to characterize the virulence profiles of staphylococcal strains involved in difficult-to-treat skin and soft tissue infections, from both phenotypic and genotypic points of view. Phenotypic ability of the strains to secrete soluble virulence factors was assessed by a culturing dependent assay and their capacity to develop biofilms on inert substrate was screened by an adapted crystal violet microtiter method. We also tested the presence of several virulence genes by PCR. Most of the studied strains were isolated from purulent secretions of acne lesions and frequently secreted two or three soluble virulence factors. Most frequently secreted soluble virulence factors were caseinase (89%), lipase (71%) and leci...
The interaction of nanomaterials with cells and lipid bilayers is critical in many applications s... more The interaction of nanomaterials with cells and lipid bilayers is critical in many applications such as phototherapy, imaging and drug/gene delivery. These applications require a firm control over nanoparticle-cell interactions, which are mainly dictated by surface properties of the nanoparticles. The aim of this study was to investigate the interaction of Fe3O4 nanoparticles functionalized with several wide use antibiotics with opossum kidney (OK) cellular membranes in order to reveal changes in the membrane organization at different temperatures. We also investigated the in vivo biodistribution of the tested nanoparticles in a mouse model. Our results showed that, at low temperatures (31-35°C), plain Fe3O4 nanoparticles induced a drop of the membrane fluidity, while at physiological or higher temperatures (37-39°C) the membrane fluidity was increased. On the other hand, when nanoparticles functionalized with the tested antibiotics were used, we observed that the effect was opposit...
Pathogenic bacteria have the ability to sense their versatile environment and adapt by behavioral... more Pathogenic bacteria have the ability to sense their versatile environment and adapt by behavioral changes both to the external reservoirs and the infected host, which, in response to microbial colonization, mobilizes equally sophisticated anti-infectious strategies. One of the most important adaptive processes is the ability of pathogenic bacteria to turn from the free, floating, or planktonic state to the adherent one and to develop biofilms on alive and inert substrata; this social lifestyle, based on very complex communication networks, namely, the quorum sensing (QS) and response system, confers them an increased phenotypic or behavioral resistance to different stress factors, including host defense mechanisms and antibiotics. As a consequence, biofilm infections can be difficult to diagnose and treat, requiring complex multidrug therapeutic regimens, which often fail to resolve the infection. One of the most promising avenues for discovering novel and efficient antibiofilm stra...
Bacterial infections are an important public health issue, especially those difficult to treat du... more Bacterial infections are an important public health issue, especially those difficult to treat due to antibiotic resistance. Besides the antibiotic resistance, the majority of bacterial strains have the ability of forming specific multicellular communities, named biofilms, which have an increased tolerance to all known antimicrobial substances, and also to the host protection mechanisms. This study had as objective the analysis of the antibiotic susceptibility, adherence capacity and biofilm development, as well as producing of soluble virulence factors, with an important role in the progression of an infectious process for Staphylococcus spp. strains used to obtain bacterial autologous vaccines. Most bacteria were resistant to penicillin, erythromycin, fusidic acid and clindamycin. All tested strains, particularly Staphylococcus epidermidis ones, produced biofilm and adhered to cell cultures in vitro. They also had the ability to produce various soluble virulence factors (i.e., pro...
Abstract Due to their enhanced properties, such as their nanometric dimensions, increased surface... more Abstract Due to their enhanced properties, such as their nanometric dimensions, increased surface area, excellent surface chemistry, and their possibility to be functionalized, the nanostructured materials are used in a wide variety of different domains including the biomedical one. In order to develop biomedical devices, all nanostructures must be toxicologically tested. Even though the results of these tests are controversial and contradictory, they are mandatory for the evaluation of nanomaterials’ interactions with the biological systems. This study contributed to a general picture of the toxicological responses that nanomaterials can generate. Besides the size and the concentration of nanoparticles, there are several factors that influence their cytotoxicity, such as aggregation state, shape, chemistry, biodistribution, etc. However, the toxic effects could be diminished by capping or coating the nanoparticles. Without any doubt, the nanotechnology area is a tremendous resource for research studies especially in view of the fact that it represents a reserve that provides nanomaterials with promising applications in biomedicine that still need to be exploited.
One of the most important goals of EU nature and water framework directives is to ensure healthy ... more One of the most important goals of EU nature and water framework directives is to ensure healthy aquatic ecosystems by the protection of the most valuable species and habitats form the Natura 2000 network, while at the same time ensuring a balance between water/nature protection and the sustainable use of nature’s natural resources. The purpose of this study was to evaluate the physico-chemical and microbiological characteristics of four Romanian salty plain lakes included in Natura 2000 Network, in order to assess the degree of organic pollution and to generate the knowledge required for the design and implementation of appropriate measures for maintaining the balance between the water protection and the sustainable use of these protected ecosystems. The water and sediment sampling was performed in two consecutive years (2015 and 2016), in September and the following standard parameters have been determined: pH, chemical oxygen consumption (COC), the degree of trophicity and salini...
A significant amount of research has been performed to investigate the impact of genetically modi... more A significant amount of research has been performed to investigate the impact of genetically modified foods (GMFs) on human health. GMFs have the potential to solve many of the world’s problems; for example, they can help with the current food crisis and can decrease the pollution rate by reducing the use of pesticides and herbicides since increased pest resistance is one of the most relevant properties of genetically modified organisms. The main goal of this review is to assess the advantages and disadvantages of GMFs (plants and animals) in human consumption and to dissect the economic concerns associated with their use.
In the last few decades, nanomaterials have been intensively researched for numerous biomedical a... more In the last few decades, nanomaterials have been intensively researched for numerous biomedical applications, including targeted drug delivery, due to their unique properties such as dimensions, biocompatibility, surface chemistry, stability in physiological conditions, and modifiable toxicity. The toxicity of nanomaterials can prove to be a challenging subject, however changing different physicochemical properties of nanomaterials can alter their toxic behavior. Further research needs to be done on in vivo toxicity based on the physiological effect of acute and chronic adverse effects caused by nanoparticles. In order to properly and safely design future nanotechnologies, there is a need for a fundamental understanding of the interactions between nanomaterials and biological tissues.
Biofilms represent an increasing challenge in the medical practice worldwide, imposing a serious ... more Biofilms represent an increasing challenge in the medical practice worldwide, imposing a serious threat to public health. As bacterial strains have developed antibiotic resistance, researcher’s attention has been extensively focused on developing more efficient antimicrobial strategies. In this context, the present study reports the synthesis, physicochemical characterization, ex vivo biodistribution, and in vitro evaluation of the capacity of nanostructured surfaces based on zinc oxide (ZnO) and biologically active molecules to modulate clinically relevant microbial biofilms. ZnO nanoparticles (NPs) were synthesized through a co-precipitation method without thermal treatment. The matrix-assisted pulsed laser evaporation (MAPLE) was applied for preparing nanostructured coatings based on ZnO NPs surface modified with linalool that were further characterized by X-ray diffraction (XRD), thermogravimetric analysis with differential scanning calorimetry (TGA-DSC), scanning electron micro...
Abstract Core–shell nanoparticles (NPs) are progressively attracting more attention, since the af... more Abstract Core–shell nanoparticles (NPs) are progressively attracting more attention, since the aforementioned NPs have arisen at the border between applied materials chemistry and nanotechnology. The particles display distinctive properties of the diverse materials combined. This is particularly true in terms of the inherent ability to influence the surface functions to meet the varied application needs. Nanomaterials possess well-known antimicrobial activity against several microorganisms and have been thoroughly investigated in terms of cancer research. A lot of antimicrobial nanostructures, such as zinc oxide, silver, gold, and iron oxide NPs, have been technologically engineered recently in order to kill or prevent the growth of pathogenic microbes. Even though there has been a lot of improvement in the understanding of cancer, this condition is still a main leading cause of mortality and morbidity. Because of the several disadvantages of conventional treatments, such as severe side effects and lack of specificity, core–shell NPs–based therapies have been intensely investigated over the last several years. Therapies such as hyperthermia, targeted drug delivery, and a combination of radiotherapy and photothermal therapy are still under research and show promising results when aided by core–shell NPs. Given the versatility in the synthesis of these NPs, numerous types of materials can be used in order to manufacture core–shell nanosystems that are biocompatible and have specific properties, depending on the applications in which they are used.
Considering the large number of the multiresistant bacterial strains and the increasing need in n... more Considering the large number of the multiresistant bacterial strains and the increasing need in new antimicrobial formulation, the aim of this study was to evaluate the antipathogenic effect of E. caryophyllata essential oil on collection and recently isolated clinical strains of P. aeruginosa and S. aureus. Experimental assays were carried out by in vitro and in vivo tests. Qualitative and quantitative assessment of the antimicrobial activity was followed by the analysis of the essential oil influence on enzymatic soluble virulence factors expression. The cytotoxic effect of the vegetal extract was quantified by using HeLa cells. Nanosystem embedded essential oil was used to establish the in vivo antipathogenic effect on mice. Qualitative screening results revealed an early microbicidal effect quantified by low minimum inhibitory concentration values. The in vivo study showed a stabiliziation of the essential oil biological activities when using nanosystem embedding, that could be ...
Despite the recent biomedical advances in diagnosis and therapy, cartilage and muscle disorders r... more Despite the recent biomedical advances in diagnosis and therapy, cartilage and muscle disorders represent debilitating conditions with massive economical, social and clinical impacts. Severe complications of such difficult-to-treat or untreatable diseases limit current therapeutic approaches and lead to the acute need for development of novel therapeutic or reparatory strategies. Current research is increasingly focused on finding or obtaining suitable materials with specific biomedical traits to be used as competitive candidates in the engineering of new tissues and organs to replace or heal damaged tissues. The purpose of this study is to present the most prevalent cartilage- and muscular-tissue-related diseases and highlight the recent scientific progress regarding the development of classical and recent therapeutic approaches, focusing on discussing the impact and advantages of bioactive nanomaterials in designing functional scaffolds for cartilage and muscle repair.
Nanotherapeutics have received an increased attention in the recent years especially because of t... more Nanotherapeutics have received an increased attention in the recent years especially because of their impact in medicine, being successfully utilized as antimicrobial agents, targeted drug delivery systems, anticancer drugs, and so on. In this chapter, we aimed to make an updated screening of the main inorganic and organic nanosystems with antimicrobial and antitumor properties, which are the most inciting and investigated approaches in nanotherapy. We also discussed the main issues regarding their clinical use, properties of these systems, driving mechanism, and highlighted their advantages and disadvantages for modern therapy.
Received: 10.01.2013 This study reports the effect of some essential oils (EOs) and of some of th... more Received: 10.01.2013 This study reports the effect of some essential oils (EOs) and of some of their major fractions on soluble virulence factors and quorum sensing (QS) gene expression profiles of 15 Staphylococcus aureus and Pseudomonas aeruginosa clinical strains. EOs were extracted from various angiosperm and gymnosperm vegetal taxons by hydrodistillation in a Neo-Clevengertype apparatus and characterized by measuring the density and refractive index, as well as by gas chromatographic analysis. EOs and their major components proved to inhibit the phenotypic expression of six soluble virulence determinants (haemolysins, gelatinase, DN-ase, lipase, amylase, esculin hydrolysis) when used in sub-inhibitory concentrations, in both P. aeruginosa and S. aureus strains. EOs extracted from Salvia officinalis, Rosmarinus officinalis, Abies alba and Eugenia caryophyllata as well as some of their major compounds (limonene, eugenol and eucalyptol) inhibited QS genes expression in S. aureus, ...
Chronic infections represent an important burden on the healthcare system and have a significant ... more Chronic infections represent an important burden on the healthcare system and have a significant impact on the patients’ quality of life. While Staphylococcus spp. are commensal bacteria, they can become pathogenic, leading to various types of infections. In this study we aimed to characterize the virulence profiles of staphylococcal strains involved in difficult-to-treat skin and soft tissue infections, from both phenotypic and genotypic points of view. Phenotypic ability of the strains to secrete soluble virulence factors was assessed by a culturing dependent assay and their capacity to develop biofilms on inert substrate was screened by an adapted crystal violet microtiter method. We also tested the presence of several virulence genes by PCR. Most of the studied strains were isolated from purulent secretions of acne lesions and frequently secreted two or three soluble virulence factors. Most frequently secreted soluble virulence factors were caseinase (89%), lipase (71%) and leci...
The interaction of nanomaterials with cells and lipid bilayers is critical in many applications s... more The interaction of nanomaterials with cells and lipid bilayers is critical in many applications such as phototherapy, imaging and drug/gene delivery. These applications require a firm control over nanoparticle-cell interactions, which are mainly dictated by surface properties of the nanoparticles. The aim of this study was to investigate the interaction of Fe3O4 nanoparticles functionalized with several wide use antibiotics with opossum kidney (OK) cellular membranes in order to reveal changes in the membrane organization at different temperatures. We also investigated the in vivo biodistribution of the tested nanoparticles in a mouse model. Our results showed that, at low temperatures (31-35°C), plain Fe3O4 nanoparticles induced a drop of the membrane fluidity, while at physiological or higher temperatures (37-39°C) the membrane fluidity was increased. On the other hand, when nanoparticles functionalized with the tested antibiotics were used, we observed that the effect was opposit...
Pathogenic bacteria have the ability to sense their versatile environment and adapt by behavioral... more Pathogenic bacteria have the ability to sense their versatile environment and adapt by behavioral changes both to the external reservoirs and the infected host, which, in response to microbial colonization, mobilizes equally sophisticated anti-infectious strategies. One of the most important adaptive processes is the ability of pathogenic bacteria to turn from the free, floating, or planktonic state to the adherent one and to develop biofilms on alive and inert substrata; this social lifestyle, based on very complex communication networks, namely, the quorum sensing (QS) and response system, confers them an increased phenotypic or behavioral resistance to different stress factors, including host defense mechanisms and antibiotics. As a consequence, biofilm infections can be difficult to diagnose and treat, requiring complex multidrug therapeutic regimens, which often fail to resolve the infection. One of the most promising avenues for discovering novel and efficient antibiofilm stra...
Bacterial infections are an important public health issue, especially those difficult to treat du... more Bacterial infections are an important public health issue, especially those difficult to treat due to antibiotic resistance. Besides the antibiotic resistance, the majority of bacterial strains have the ability of forming specific multicellular communities, named biofilms, which have an increased tolerance to all known antimicrobial substances, and also to the host protection mechanisms. This study had as objective the analysis of the antibiotic susceptibility, adherence capacity and biofilm development, as well as producing of soluble virulence factors, with an important role in the progression of an infectious process for Staphylococcus spp. strains used to obtain bacterial autologous vaccines. Most bacteria were resistant to penicillin, erythromycin, fusidic acid and clindamycin. All tested strains, particularly Staphylococcus epidermidis ones, produced biofilm and adhered to cell cultures in vitro. They also had the ability to produce various soluble virulence factors (i.e., pro...
Abstract Due to their enhanced properties, such as their nanometric dimensions, increased surface... more Abstract Due to their enhanced properties, such as their nanometric dimensions, increased surface area, excellent surface chemistry, and their possibility to be functionalized, the nanostructured materials are used in a wide variety of different domains including the biomedical one. In order to develop biomedical devices, all nanostructures must be toxicologically tested. Even though the results of these tests are controversial and contradictory, they are mandatory for the evaluation of nanomaterials’ interactions with the biological systems. This study contributed to a general picture of the toxicological responses that nanomaterials can generate. Besides the size and the concentration of nanoparticles, there are several factors that influence their cytotoxicity, such as aggregation state, shape, chemistry, biodistribution, etc. However, the toxic effects could be diminished by capping or coating the nanoparticles. Without any doubt, the nanotechnology area is a tremendous resource for research studies especially in view of the fact that it represents a reserve that provides nanomaterials with promising applications in biomedicine that still need to be exploited.
One of the most important goals of EU nature and water framework directives is to ensure healthy ... more One of the most important goals of EU nature and water framework directives is to ensure healthy aquatic ecosystems by the protection of the most valuable species and habitats form the Natura 2000 network, while at the same time ensuring a balance between water/nature protection and the sustainable use of nature’s natural resources. The purpose of this study was to evaluate the physico-chemical and microbiological characteristics of four Romanian salty plain lakes included in Natura 2000 Network, in order to assess the degree of organic pollution and to generate the knowledge required for the design and implementation of appropriate measures for maintaining the balance between the water protection and the sustainable use of these protected ecosystems. The water and sediment sampling was performed in two consecutive years (2015 and 2016), in September and the following standard parameters have been determined: pH, chemical oxygen consumption (COC), the degree of trophicity and salini...
A significant amount of research has been performed to investigate the impact of genetically modi... more A significant amount of research has been performed to investigate the impact of genetically modified foods (GMFs) on human health. GMFs have the potential to solve many of the world’s problems; for example, they can help with the current food crisis and can decrease the pollution rate by reducing the use of pesticides and herbicides since increased pest resistance is one of the most relevant properties of genetically modified organisms. The main goal of this review is to assess the advantages and disadvantages of GMFs (plants and animals) in human consumption and to dissect the economic concerns associated with their use.
In the last few decades, nanomaterials have been intensively researched for numerous biomedical a... more In the last few decades, nanomaterials have been intensively researched for numerous biomedical applications, including targeted drug delivery, due to their unique properties such as dimensions, biocompatibility, surface chemistry, stability in physiological conditions, and modifiable toxicity. The toxicity of nanomaterials can prove to be a challenging subject, however changing different physicochemical properties of nanomaterials can alter their toxic behavior. Further research needs to be done on in vivo toxicity based on the physiological effect of acute and chronic adverse effects caused by nanoparticles. In order to properly and safely design future nanotechnologies, there is a need for a fundamental understanding of the interactions between nanomaterials and biological tissues.
Biofilms represent an increasing challenge in the medical practice worldwide, imposing a serious ... more Biofilms represent an increasing challenge in the medical practice worldwide, imposing a serious threat to public health. As bacterial strains have developed antibiotic resistance, researcher’s attention has been extensively focused on developing more efficient antimicrobial strategies. In this context, the present study reports the synthesis, physicochemical characterization, ex vivo biodistribution, and in vitro evaluation of the capacity of nanostructured surfaces based on zinc oxide (ZnO) and biologically active molecules to modulate clinically relevant microbial biofilms. ZnO nanoparticles (NPs) were synthesized through a co-precipitation method without thermal treatment. The matrix-assisted pulsed laser evaporation (MAPLE) was applied for preparing nanostructured coatings based on ZnO NPs surface modified with linalool that were further characterized by X-ray diffraction (XRD), thermogravimetric analysis with differential scanning calorimetry (TGA-DSC), scanning electron micro...
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Papers by Alina-Maria Holban