| 1. |
|
|
| 2. |
- Lademann, Jürgen, et al.
(författare)
-
Drug delivery with topically applied nanoparticles : science fiction or reality
- 2013
-
Ingår i: Skin Pharmacology and Physiology. - : S. Karger. - 1660-5527 .- 1660-5535. ; 26:4-6, s. 227-233
-
Tidskriftsartikel (refereegranskat)abstract
- The efficacy of topically applied drugs is determined by their action mechanism and their potential capacity of passing the skin barrier. Nanoparticles are assumed to be efficient carrier systems for drug delivery through the skin barrier. For flexible nanoparticles like liposomes, this effect has been well demonstrated. The penetration properties of solid nanoparticles are currently under intensive investigation. The crucial advantage of nanoparticles over non-particulate substances is their capability to penetrate deeply into the hair follicles where they can be stored for several days. There is no evidence, yet, that solid particles ≥40 nm are capable of passing through the healthy skin barrier. Therefore and in spite of the long-standing research efforts in this field, commercially available solid nanoparticle-based products for drug delivery through the healthy skin are still missing. Nevertheless, the prospects for the clinical use of nanoparticles in drug delivery are tremendous. They can be designed as transport systems delivering drugs efficiently into the hair follicles in the vicinity of specific target structures. Once deposited at these structures, specific signals might trigger the release of the drugs and exert their effects on the target cells. In this article, examples of such triggered drug release are presented.
|
|
| 3. |
- Patzelt, Alexa, et al.
(författare)
-
Do nanoparticles have a future in dermal drug delivery?
- 2017
-
Ingår i: Journal of Controlled Release. - : ELSEVIER SCIENCE BV. - 0168-3659 .- 1873-4995. ; 246, s. 174-182
-
Tidskriftsartikel (refereegranskat)abstract
- More and more investigations confirm that nanoparticles are incapable of overcoming the intact skin barrier in vivo. Do nanoparticles still have a future in dermal drug delivery? Unlike many other topically applied substances, nanoparticles have not been reported to utilize the intercellular penetration pathway and preferentially make use of the follicular penetration pathway. Deep penetration into the follicular ducts has been described for a variety of particles and appears to be strongly influenced by particle size. For targeted drug delivery, smart nanoparticles are required which are able to release their loaded drugs subsequent to internal or external trigger stimuli, and thereby enable the translocation of the active agents into the viable epidermis. In the recent manuscript, three nanoparticles systems are summarized and compared which release their model drugs upon different trigger mechanisms. The BSA hydrogel nanoparticles release their model drug TRITC-dextran by passive diffusion due to a concentration gradient via a porous surface. The protease-triggered controlled release BSA nanoparticles release their model drug if they are applied simultaneously with protease nanoparticles, resulting in an enzymatic degradation of the particles and a release of the model drug FITC. Finally, the IR-triggered controlled release AuNP-doped BSA nanoparticles release their model drug FITC after photoactivation with wIRA. For all three nanoparticle systems, the release of their model drugs could be observed. For the first nanoparticle system, only low follicular penetration depths were found which might by due do an agglomeration effect. For the last two nanoparticle systems, deep follicular penetration and even an uptake by the sebaceous glands were verified. In conclusion, it could be demonstrated that nanoparticles do have a future in dermal drug delivery if smart nanoparticle systems are utilized which are able to release their drug at specific times and locations within the hair follicle. (C) 2016 Elsevier B.V. All rights reserved.
|
|
| 4. |
- Sarkar, Anjana, 1978-, et al.
(författare)
-
Photocatalytic activity of TiO2 nanoparticles : effect of thermal annealing under various gaseous atmospheres
- 2012
-
Ingår i: Nanotechnology. - : Institute of Physics Publishing (IOPP). - 0957-4484 .- 1361-6528. ; 23:47, s. 475711-475719
-
Tidskriftsartikel (refereegranskat)abstract
- The structure, composition and photocatalytic activity of TiO2 nanoparticles annealed in various gas atmospheres (N2, NH3 and H2) were studied in this work. The effect of treatment on crystal structure, particle size, chemical composition and optical absorbance were assessed by means of x-ray diffraction, transmission electron microscopy, x-ray photoelectron spectroscopy and diffuse optical reflectance/transmittance measurements, respectively. Photocatalytic properties of the materials were evaluated by three different methods: degradation of methyl orange in water, killing of Staphylococcus aureus bacteria and photogeneration of radicals in the presence of 3-carboxy-2,2,5,5-tetramethyl pyrrolidine-1-oxyl (PCA) marker molecules. The results indicate that the correlation between pretreatment and the photocatalytic performance depends on the photocatalytic processes and cannot be generalized.
|
|
| 5. |
- Tran, Ngo Bich Nga Nathalie, et al.
(författare)
-
Gradient-dependent release of the model drug TRITC-dextran from FITC-labeled BSA hydrogel nanocarriers in the hair follicles of porcine ear skin
- 2017
-
Ingår i: European journal of pharmaceutics and biopharmaceutics. - : ELSEVIER SCIENCE BV. - 0939-6411 .- 1873-3441. ; 116, s. 12-16
-
Tidskriftsartikel (refereegranskat)abstract
- Hair follicle research is currently focused on the development of drug-loaded nanocarriers for the targeting of follicular structures in the treatment of skin and hair follicle-related disorders. In the present study, a dual-label nanocarrier system was implemented in which FITC-labeled BSA hydrogel nanocarriers loaded with the model drug and dye TRITC-dextran were applied topically to porcine ear skin. Follicular penetration and the distribution of both dyes corresponding to the nanocarriers and the model drug in the follicular ducts subsequent to administration to the skin were investigated using confocal laser scanning microscopy. The release of TRITC-dextran from the particles was induced by washing of the nanocarriers, which were kept in a buffer containing TRITC-labeled dextran to balance out the diffusion of the dextran during storage, thereby changing the concentration gradient. The results showed a slightly but statistically significantly deeper follicular penetration of fluorescent signals corresponding to TRITC-dextran as opposed to fluorescence corresponding to the FITC-labeled particles. The different localizations of the dyes in the cross-sections of the skin samples evidenced the release of the model drug from the labeled nanoparticles. (C) 2016 Elsevier B.V. All rights reserved.
|
|
| 6. |
- Trunina, Natalia A., et al.
(författare)
-
Monitoring of TiO2 and ZnO Nanoparticle Penetration Into Fnamel and Dentine of Human Tooth IN VITRO and Assessment of Their Photocatalytic Ability
- 2014
-
Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - 1077-260X .- 1558-4542. ; 20:3, s. Article Number: UNSP 7300108-
-
Tidskriftsartikel (refereegranskat)abstract
- Penetration of nanoparticles into tooth enamel and dentine is of significant interest upon solving problems related to reduction of tooth sensitivity, enamel strengthening, disinfection, restoration as well as cosmetic bleaching. This paper aims at studying the process of nanoparticle penetration into tooth enamel and dentine samples using nonlinear optical microscopy and at investigating the influence of the same nanoparticles on the generation of free radicals using the electronic paramagnetic resonance technique. We presented in vitro measurements demonstrating that nonlinear optical microscopy, namely, two-photon-excited autfluorescence, second harmonic generation, and hyper-Rayleigh scattering-based microscopy can be used for monitoring and imaging TiO2 and ZnO nanoparticle penetration into tooth tissues. The results indicate that ZnO nanoparticles penetrated into the human tooth enamel and dentine up to a depth of 12 and 45 mu m, respectively, and TiO2 nanoparticles penetrated into dentine to a depth of 5 mu m. The penetration mainly- occurs along either enamel rods or dentinal tubules. Permeability of the dentine was found to be higher than that of enamel (for ZnO particles) by one order of magnitude and the diffusion rate was affected by the particle size being higher for smaller, submicron particles (ZnO) than for micronsized aggregates (TiO2 I. Nitrogen-doped TiO2 nanoparticles generate more radicals in the UV-VIS spectral range in comparison to pristine TiO2 (anatase) and ZnO nanoparticles, therefore, they can potentially be used for disinfection purposes of superficial tooth areas (up to 5-mu m deep).
|
|
