Mojgan Talebi - Academia.edu (original) (raw)
Papers by Mojgan Talebi
Objectives and methods: The objective of this study was to investigate the key factors involved i... more Objectives and methods: The objective of this study was to investigate the key factors involved in PDT efficacy of both photosensitizers in an ex vivo situation during different fungal growth stages using a recently developed ex vivo model. The study focused on the influence of pH and ion strength of incu- bation media, photochemical properties of the photosensitizers (spectra and
The Journal of Antimicrobial Chemotherapy, Jan 9, 2007
Background: Dermatophytes are fungi that can cause infections of skin, hair and nails because of ... more Background: Dermatophytes are fungi that can cause infections of skin, hair and nails because of their ability to feed on keratin. Superficial mycoses are among the most prevalent infectious diseases worldwide. Two important restrictions of current therapeutic options are the recurrence of the infection and prolonged treatment. This is especially true for infections caused by Trichophyton rubrum, a widely distributed dermatophyte. The application of photosensitizers for treatment of fungal infections is, within the field of photodynamic treatment (PDT), relatively new. Recently, we demonstrated that the porphyrins 5,10,15-tris (4-methylpyridinium)-20-phenyl-[21H,23H]-porphine trichloride (Sylsens B) and deuteroporphyrin monomethylester (DP mme) were excellent photosensitizers towards T. rubrum when using red light.
![Research paper thumbnail of Preclinical Studies with 5,10,15-Tris(4-Methylpyridinium)-20-Phenyl-[21 H ,23 H ]-Porphine Trichloride for the Photodynamic Treatment of Superficial Mycoses Caused by Trichophyton rubrum](https://attachments.academia-assets.com/49054809/thumbnails/1.jpg)
](Photochemistry and Photobiology, 2009
Dermatophytes are fungi that cause infections of keratinized tissues. We have recently demonstrat... more Dermatophytes are fungi that cause infections of keratinized tissues. We have recently demonstrated the susceptibility of the dermatophyte Trichophyton rubrum to photodynamic treatment (PDT) with 5,10,15-Tris(4-methylpyridinium)-20-phenyl-[21H,23H]porphine trichloride (Sylsens B) in 5 mM M citric acid ⁄ sodium citrate buffer (pH 5.2, formulation I). In this work, we examined the penetration of Sylsens B in healthy and with T. rubrum infected skin and we investigated the susceptibility of T. rubrum to PDT using formulation I and UVA-1 radiation (340-550 nm). Skin penetration studies were performed with formulations I and II (Sylsens B in PBS, pH 7.4) applied on dermatomed skin, human stratum corneum (SC), disrupted SC by T. rubrum growth and SC pretreated with a detergent. No penetration was observed in healthy skin. Disruption of SC by preceding fungal growth caused Sylsens B penetration at pH 7.4, but not at pH 5.2. However, chemically damaged SC allowed Sylsens B to penetrate also at pH 5.2. UVA-1 PDT was applied ex vivo during two fungal growth stages of two T. rubrum strains (CBS 304.60 and a clinical isolate). Both strains could be killed by UVA-1 alone (40 J/cm 2 ). Combined with formulation I (1 and 10 lM M Sylsens B for, respectively, CBS 304.60 and the clinical isolate), only 18 J/cm 2 UVA-1 was required for fungal kill. Therefore, PDT with 10 lM M Sylsens B (formulation I) and 18 J/ cm 2 UVA-1 could be considered as effective and safe. This offers the possibility to perform clinical studies in future.
Journal of Antimicrobial Chemotherapy, 2007
Background: Photodynamic treatment (PDT) refers to a treatment with light-activated agents ( phot... more Background: Photodynamic treatment (PDT) refers to a treatment with light-activated agents ( photosensitizers) in combination with visible light and molecular oxygen. Recently, we have demonstrated that the porphyrins, 5,10,15-tris(4-methylpyridinium)-20-phenyl-[21H,23H]-porphine trichloride (Sylsens B) and deuteroporphyrin monomethylester (DP mme) are excellent photosensitizers to be used against Trichophyton rubrum both in vitro and ex vivo.
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2015
ABSTRACT In this paper, the authors demonstrate a novel spatial atomic layer deposition (ALD) pro... more ABSTRACT In this paper, the authors demonstrate a novel spatial atomic layer deposition (ALD) process based on pneumatic transport of nanoparticle agglomerates. Nanoclusters of platinum (Pt) of ∼1 nm diameter are deposited onto titania (TiO2) P25 nanoparticles resulting to a continuous production of an active photocatalyst (0.12–0.31 wt. % of Pt) at a rate of about 1 g min−1. Tuning the precursor injection velocity (10–40 m s−1) enhances the contact between the precursor and the pneumatically transported support flows. Decreasing the chemisorption temperature (from 250 to 100 °C) results in more uniform distribution of the Pt nanoclusters as it decreases the reaction rate as compared to the rate of diffusion into the nanoparticle agglomerates. Utilizing this photocatalyst in the oxidation reaction of Acid Blue 9 showed a factor of five increase of the photocatalytic activity compared to the native P25 nanoparticles. The use of spatial particle ALD can be further expanded to deposition of nanoclusters on porous, micron-sized particles and to the production of core–shell nanoparticles enabling the robust and scalable manufacturing of nanostructured powders for catalysis and other applications.
The development of new therapies can be conditioned by the lack of suitable and effective ways to... more The development of new therapies can be conditioned by the lack of suitable and effective ways to carry the biological molecules into the target inside the patient's body. The small amounts of the biomolecules are very difficult to quantify in the solid state and is not always possible to use a simple excipient. Very frequently, the size and density differences between the biomolecules and the excipient are so large that a uniform distribution of the therapeutic cannot be ensured, especially when they are not compacted in a tablet. This is the case for certain dry powder inhalers and powders to prepare suspensions. In addition, the properties of the excipient can improve the formulation by reducing the risk of local overdose and by giving an additional control over the farmacokinetics, as long as it is ensured that it does not separate from the biomolecule in the exact instant when it enters the patient's body. This feature has been used and widely described in literature th...
Physical Chemistry Chemical Physics, 2013
The effect of surface characteristics on the interaction between nanoparticles and their agglomer... more The effect of surface characteristics on the interaction between nanoparticles and their agglomeration in dense gas suspensions is still not fully understood. It is known that when the surface is covered with hydroxyl groups, the interaction between nanoparticles becomes substantially stronger than in the absence of these groups; this strengthening is typically attributed to the formation of capillary bridges between the particles. However, this work shows that part of the increase of the interaction is due to the direct hydrogen bonds formed between the surfaces of the polar particles. Dry nitrogen was used to fluidize polar (hydrophilic) and apolar (hydrophobic) SiO 2 , TiO 2 and Al 2 O 3 particles, with a size ranging from 13 to 21 nm. The dry polar particles showed smaller bed expansion and larger minimum fluidization velocity compared to their apolar counterparts, indicating stronger interparticle forces. The results show the importance of including the formation of hydrogen bonds in the modeling of the interaction between dry and polar nanoparticles.
Chem. Commun., 2015
Molecular layer deposition (MLD) was used to coat micron-sized protein particles in a fluidized b... more Molecular layer deposition (MLD) was used to coat micron-sized protein particles in a fluidized bed reactor. Our results show that the dissolution rate of particles coated via MLD rapidly decreases with the increase in number of coating cycles, while the uncoated particles dissolve instantaneously.
Objectives and methods: The objective of this study was to investigate the key factors involved i... more Objectives and methods: The objective of this study was to investigate the key factors involved in PDT efficacy of both photosensitizers in an ex vivo situation during different fungal growth stages using a recently developed ex vivo model. The study focused on the influence of pH and ion strength of incu- bation media, photochemical properties of the photosensitizers (spectra and
The Journal of Antimicrobial Chemotherapy, Jan 9, 2007
Background: Dermatophytes are fungi that can cause infections of skin, hair and nails because of ... more Background: Dermatophytes are fungi that can cause infections of skin, hair and nails because of their ability to feed on keratin. Superficial mycoses are among the most prevalent infectious diseases worldwide. Two important restrictions of current therapeutic options are the recurrence of the infection and prolonged treatment. This is especially true for infections caused by Trichophyton rubrum, a widely distributed dermatophyte. The application of photosensitizers for treatment of fungal infections is, within the field of photodynamic treatment (PDT), relatively new. Recently, we demonstrated that the porphyrins 5,10,15-tris (4-methylpyridinium)-20-phenyl-[21H,23H]-porphine trichloride (Sylsens B) and deuteroporphyrin monomethylester (DP mme) were excellent photosensitizers towards T. rubrum when using red light.
Photochemistry and Photobiology, 2009
Dermatophytes are fungi that cause infections of keratinized tissues. We have recently demonstrat... more Dermatophytes are fungi that cause infections of keratinized tissues. We have recently demonstrated the susceptibility of the dermatophyte Trichophyton rubrum to photodynamic treatment (PDT) with 5,10,15-Tris(4-methylpyridinium)-20-phenyl-[21H,23H]porphine trichloride (Sylsens B) in 5 mM M citric acid ⁄ sodium citrate buffer (pH 5.2, formulation I). In this work, we examined the penetration of Sylsens B in healthy and with T. rubrum infected skin and we investigated the susceptibility of T. rubrum to PDT using formulation I and UVA-1 radiation (340-550 nm). Skin penetration studies were performed with formulations I and II (Sylsens B in PBS, pH 7.4) applied on dermatomed skin, human stratum corneum (SC), disrupted SC by T. rubrum growth and SC pretreated with a detergent. No penetration was observed in healthy skin. Disruption of SC by preceding fungal growth caused Sylsens B penetration at pH 7.4, but not at pH 5.2. However, chemically damaged SC allowed Sylsens B to penetrate also at pH 5.2. UVA-1 PDT was applied ex vivo during two fungal growth stages of two T. rubrum strains (CBS 304.60 and a clinical isolate). Both strains could be killed by UVA-1 alone (40 J/cm 2 ). Combined with formulation I (1 and 10 lM M Sylsens B for, respectively, CBS 304.60 and the clinical isolate), only 18 J/cm 2 UVA-1 was required for fungal kill. Therefore, PDT with 10 lM M Sylsens B (formulation I) and 18 J/ cm 2 UVA-1 could be considered as effective and safe. This offers the possibility to perform clinical studies in future.
Journal of Antimicrobial Chemotherapy, 2007
Background: Photodynamic treatment (PDT) refers to a treatment with light-activated agents ( phot... more Background: Photodynamic treatment (PDT) refers to a treatment with light-activated agents ( photosensitizers) in combination with visible light and molecular oxygen. Recently, we have demonstrated that the porphyrins, 5,10,15-tris(4-methylpyridinium)-20-phenyl-[21H,23H]-porphine trichloride (Sylsens B) and deuteroporphyrin monomethylester (DP mme) are excellent photosensitizers to be used against Trichophyton rubrum both in vitro and ex vivo.
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2015
ABSTRACT In this paper, the authors demonstrate a novel spatial atomic layer deposition (ALD) pro... more ABSTRACT In this paper, the authors demonstrate a novel spatial atomic layer deposition (ALD) process based on pneumatic transport of nanoparticle agglomerates. Nanoclusters of platinum (Pt) of ∼1 nm diameter are deposited onto titania (TiO2) P25 nanoparticles resulting to a continuous production of an active photocatalyst (0.12–0.31 wt. % of Pt) at a rate of about 1 g min−1. Tuning the precursor injection velocity (10–40 m s−1) enhances the contact between the precursor and the pneumatically transported support flows. Decreasing the chemisorption temperature (from 250 to 100 °C) results in more uniform distribution of the Pt nanoclusters as it decreases the reaction rate as compared to the rate of diffusion into the nanoparticle agglomerates. Utilizing this photocatalyst in the oxidation reaction of Acid Blue 9 showed a factor of five increase of the photocatalytic activity compared to the native P25 nanoparticles. The use of spatial particle ALD can be further expanded to deposition of nanoclusters on porous, micron-sized particles and to the production of core–shell nanoparticles enabling the robust and scalable manufacturing of nanostructured powders for catalysis and other applications.
The development of new therapies can be conditioned by the lack of suitable and effective ways to... more The development of new therapies can be conditioned by the lack of suitable and effective ways to carry the biological molecules into the target inside the patient's body. The small amounts of the biomolecules are very difficult to quantify in the solid state and is not always possible to use a simple excipient. Very frequently, the size and density differences between the biomolecules and the excipient are so large that a uniform distribution of the therapeutic cannot be ensured, especially when they are not compacted in a tablet. This is the case for certain dry powder inhalers and powders to prepare suspensions. In addition, the properties of the excipient can improve the formulation by reducing the risk of local overdose and by giving an additional control over the farmacokinetics, as long as it is ensured that it does not separate from the biomolecule in the exact instant when it enters the patient's body. This feature has been used and widely described in literature th...
Physical Chemistry Chemical Physics, 2013
The effect of surface characteristics on the interaction between nanoparticles and their agglomer... more The effect of surface characteristics on the interaction between nanoparticles and their agglomeration in dense gas suspensions is still not fully understood. It is known that when the surface is covered with hydroxyl groups, the interaction between nanoparticles becomes substantially stronger than in the absence of these groups; this strengthening is typically attributed to the formation of capillary bridges between the particles. However, this work shows that part of the increase of the interaction is due to the direct hydrogen bonds formed between the surfaces of the polar particles. Dry nitrogen was used to fluidize polar (hydrophilic) and apolar (hydrophobic) SiO 2 , TiO 2 and Al 2 O 3 particles, with a size ranging from 13 to 21 nm. The dry polar particles showed smaller bed expansion and larger minimum fluidization velocity compared to their apolar counterparts, indicating stronger interparticle forces. The results show the importance of including the formation of hydrogen bonds in the modeling of the interaction between dry and polar nanoparticles.
Chem. Commun., 2015
Molecular layer deposition (MLD) was used to coat micron-sized protein particles in a fluidized b... more Molecular layer deposition (MLD) was used to coat micron-sized protein particles in a fluidized bed reactor. Our results show that the dissolution rate of particles coated via MLD rapidly decreases with the increase in number of coating cycles, while the uncoated particles dissolve instantaneously.