Claus-Michael Lehr

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The penetration and storage behavior of dye-containing nanoparticles (diameter 320 nm) into the hair follicles was investigated. The results were compared to the findings obtained with the same amount of dye in the non-particle form. In the first part of the experiments, the penetration of the dye into the hair follicles was investigated in vitro on porcine(More)
The use of nanoparticles for targeted oral drug delivery to the inflamed gut tissue in inflammatory bowel disease was examined. Such a strategy of local drug delivery would be a distinct improvement compared with existing colon delivery devices for this disease. An experimental colitis was induced by trinitrobenzenesulfonic acid to male Wistar rats.(More)
The CFBE41o- cell line was generated by transformation of cystic fibrosis (CF) tracheo-bronchial cells with SV40 and has been reported to be homozygous for the ΔF508 mutation. A systematic characterisation of these cells, which however, is a pre-requisite for their use as an in vitro model, has not been undertaken so far. Here, we report an assessment of(More)
  • C M Lehr
  • Journal of controlled release : official journal…
  • 2000
This paper reviews some recent developments in the area of bioadhesive drug delivery systems. The area of bioadhesion in drug delivery had started some 20 years ago by using so-called mucoadhesive polymers. Many of these polymers were already used as excipients in pharmaceutical formulations. This has facilitated the development of the first bioadhesive(More)
Purpose. The size-dependent deposition of microparticles and nanoparticles after oral administration to rats using an experimental model colitis was examined. Local delivery of an entrapped drug could reduce side effects and would be a distinct improvement compared with existing colon delivery devices. Methods. Ulcerative colitis was induced in Lewis rats(More)
This investigation is focused on the enhancement of in vitro transfection activity by optimizing cationic lipid and matrix lipid composition of solid lipid nanoparticles (SLN). For this purpose SLN were formulated by using two different matrix lipids and six different cationic detergents. These 12 formulations were tested for physical parameters such as(More)
Cationically modified poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles have recently been introduced as novel carriers for DNA/RNA delivery. The colloidal characteristics of the nanoparticles--particle size and surface charge--are considered the most significant determinants in the cellular uptake and trafficking of the nanoparticles. Therefore, our aim(More)
The application of nanoparticles on a sub-cellular level necessitates an in depth study of their biocompatibility. However, complete characterization of the particles under the physiological conditions relevant for biological evaluation is still lacking. Our goal is therefore to evaluate the possible toxicity aspects of chitosan-modified PLGA nanoparticles(More)
Mucus is a complex hydrogel, comprising glycoproteins, lipids, salts, DNA, enzymes and cellular debris, covering many epithelial surfaces in the human body. Once secreted, mucin forms a barrier to protect the underlying tissues against the extracellular environment. Mucus can therefore adversely affect the absorption or action of drugs administered by the(More)
PURPOSE The aim of this study was to elucidate the expression pattern of transport proteins relevant to drug absorption in human cornea and to assess the human corneal epithelial cell line, HCE-T, regarding its use as an in vitro model for drug-absorption studies. METHODS Human corneal tissue and HCE-T cells were examined for the expression of(More)