41670121
Peptide Washout and Permeability from Glyceryl Monooleate Buccal Delivery Systems
ABSTRACT Simultaneous evaluation of the permeation and washout of a peptide from the mucoadhesive liquid crystalline phases of glyceryl monooleate (GMO) has been investigated using a donor compartment flow-through diffusion cell. [d-Ala2, d-Leu5]enkephalin (DADLE) was incorporated into the cubic and lamellar liquid crystalline phases of GMO and applied to excised porcine buccal mucosa mounted in the donor compartment flow-through cell. Phosphate-buffered saline pH 7.4 (PBS) was pumped across the upper surface of the liquid crystalline phases to mimic salivary flow. The steady-state fluxes of DADLE and GMO from the cubic phase were significantly greater than that from the lamellar phase (P<0.01). There was no statistical difference between the amounts of DADLE and GMO washed out from the lamellar and cubic phases (P>0.05). The donor compartment flow-through diffusion cell was found to be a useful tool to evaluate the impact of salivary washout on mucoadhesive oral mucosal delivery systems.
21038080
Enhancedex vivo buccal transport of propranolol: Evaluation of phospholipids as permeation enhancers
The aim of the present study was to evaluate the effects of two phospholipid permeation enhancers, lysophosphatidylcholine (LPC) and didecanoylphosphatidylcholine (DDPC), along with a fusidic acid derivative, sodium taurodihydrofusidate (STDHF) and ethanol (EtOH) on the buccal transport of propranolol hydrochloride (PPL) using anex vivo buccal diffusion model. The permeation rate of [3H]PPL as measured by steady-state fluxes increased with increasing EtOH concentration. A significant flux enhancement (P<0.05) was achieved by EtOH at 20 and 30 %v/v concentrations. At a 0.5 %w/v permeation enhancer concentration, the buccal permeation of [3H]PPL was significantly enhanced by all the enhancers studied (i.e., LPC, DDPC and STDHF) compared to the control (phosphate-buffered saline pH 7.4, PBS). LPC and DDPC displayed a greater degree of permeation enhancement compared with STDHF and EtOH-PBS mixtures with an enhancement ratio of 3.2 and 2.9 for LPC and DDPC, respectively compared with 2.0 and 1.5 for STDHF and EtOH:PBS 30:70 %v/v mixture, respectively. There was no significant difference between LPC and DDPC for the flux values and apparent permeability coefficients of [3H]PPL. These results suggest that phospholipids are suitable as permeation enhancers for the buccal delivery of drugs.
15555862
Hydrotropic Solubilization of Paclitaxel: Analysis of Chemical Structures for Hydrotropic Property
AbstractPurpose. To identify hydrotropic agents that can increase aqueous paclitaxel (PTX) solubility and to study the chemical structures necessary for hydrotropic properties so that polymeric hydrotropic agents can be synthesized.
Methods. More than 60 candidate hydrotropic agents (or hydro- tropes) were tested for their ability to increase the aqueous PTX solubility. A number of nicotinamide analogues were synthesized based on the observation that nicotinamide showed a favorable hydrotropic property. The identified hydrotropes for PTX were used to examine the structure-activity relationship.Results. N,N-Diethylnicotinamide (NNDENA) was found to be the most effective hydrotropic agent for PTX. The aqueous PTX solubility was 39 mg/ml and 512 mg/ml at NNDENA concentrations of 3.5 M and 5.95 M, respectively. These values are 5-6 orders of magnitude greater than the intrinsic solubility of 0.30 ± 0.02 μg/ml. N-Picolylnicotinamide, N-allylnicotinamide, and sodium salicylate were also excellent hydrotropes for PTX. Solubility data showed that an effective hydrotropic agent should be highly water soluble while maintaining a hydrophobic segment.
Conclusions. The present study identified several hydrotropic agents effective for increasing aqueous solubility of PTX and analyzed the structural requirements for this hydrotropic property. This information can be used to find other hydrotropic compounds and to synthesize polymeric hydrotropes that are effective for PTX and other poorly water-soluble drugs.
6921183
The effect of storage conditions on the permeability of porcine buccal mucosa
The impact of storage conditions on the permeability of porcine buccal mucosa to [3H]water and [14C]mannitol was assessed. The fresh porcine buccal tissue (fresh tissue) was obtained by utilizing pig heads within 24 hours of slaughter. The stored and frozen porcine buccal tissues (stored tissue and frozen tissue) were obtained after the storage of the tissue intact in the pig heads at 4 degrees C or -20 degrees C, respectively, for 24 h. The results demonstrated that the barrier properties of the porcine buccal mucosa were maintained with regard to [3H]water permeability when stored at 4 degrees C for 24 h. However, freezing the tissue resulted in tissue damage illustrated by a significant increase in [3H]water permeability. [14C]Mannitol does not appear to be a suitable model solute to assess the ex vivo permeability of porcine buccal mucosa due to its extremely low permeability.
26956563
Water quantitatively induces the mucoadhesion of liquid crystalline phases of glyceryl monooleate.
The possible role of water in the mucoadhesion phenomenon exhibited by the liquid crystalline phases of glyceryl monooleate was investigated using an in-vitro tensile strength technique. The mucoadhesion of the liquid crystalline phases of glyceryl monooleate was found to occur following uptake of water. The mucoadhesive force of the cubic phase was consistent since it is not capable of taking up additional water. An increase in pre-load period greatly facilitated the mucoadhesion of glyceryl monooleate (0% w/w initial water content), suggesting that the mucoadhesion is dependent upon the extent of the dehydration of the substrate. A good linear relationship between initial water content of the liquid crystalline phases and mucoadhesive force led to the conclusion that the mucoadhesive force increased with decreasing initial water concentration. Rheological properties of the liquid crystalline phases were also studied to allow a correlation between physical changes and mucoadhesion of the liquid crystalline phases, revealing that higher water concentrations in the liquid crystalline phases led to a more ordered structure that showed less mucoadhesion. The results of this study indicated that the mucoadhesive force of the liquid crystalline phases of glyceryl monooleate is determined by the capability to take up water from a water-rich environment. It may, therefore, be advantageous to use the lamellar phase as a buccal drug carrier as opposed to the relatively less mucoadhesive cubic phase.
37033683
Buccal permeation of [D-Ala(2), D-Leu(5)]enkephalin from liquid crystalline phases of glyceryl monooleate.
The ex vivo buccal permeability of a [D-Ala(2), D-Leu(5)]enkephalin (DADLE) and glyceryl monooleate (GMO) was examined from the cubic and lamellar liquid crystalline phases of GMO and aqueous phosphate-buffered saline (pH 7.4, PBS) solution across excised porcine buccal mucosa mounted in a Franz cell. GMO was released in vitro from the liquid crystalline phases indicating the erosion of the liquid crystal matrices. GMO released from the liquid crystalline matrices permeated the porcine buccal mucosa with fluxes of 0.10+/-0.03 and 0.07+/-0.00%/cm(2) per h for the cubic and lamellar phases, respectively. The flux of DADLE (1.21+/-0.32 and 1. 15+/-0.11%/cm(2) per h for the cubic and lamellar phases, respectively) from the liquid crystalline phases was significantly enhanced by the GMO compared with PBS solution (0.43+/-0.08%/cm(2) per h) during the initial permeation phase (t<3 h). Our results suggest that the cubic and lamellar liquid crystalline phases can be considered as promising buccal drug carriers for peptide drugs as well as acting as permeation enhancers.
5519498
Non-invasive quantification of brain tumor-induced astrogliosis
BackgroundCNS injury including stroke, infection, and tumor growth lead to astrogliosis, a process that involves upregulation of glial fibrillary acidic protein (GFAP) in astrocytes. However, the kinetics of astrogliosis that is related to these insults (i.e. tumor) is largely unknown.ResultsUsing transgenic mice expressing firefly luciferase under the regulation of the GFAP promoter (GFAP-luc), we developed a model system to monitor astrogliosis upon tumor growth in a rapid, non-invasive manner. A biphasic induction of astrogliosis was observed in our xenograft model in which an early phase of activation of GFAP was associated with inflammatory response followed by a secondary, long-term upregulation of GFAP. These animals reveal GFAP activation with kinetics that is in parallel with tumor growth. Furthermore, a strong correlation between astrogliosis and tumor size was observed.ConclusionsOur results suggest that non-invasive, quantitative bioluminescent imaging using GFAP-luc reporter animal is a useful tool to monitor temporal-spatial kinetics of host-mediated astrogliosis that is associated with glioma and metastatic brain tumor growth.
40463310
A rapid screening method for the detection of viable spores in powder using bioluminescence.
A rapid diagnosis of a biological threat in a powder sample is important for fi rst responders who have to make decisions on-site. The present culture-based method does not provide timely results, which is a critical barrier for a quick response when a suspicious powder sample is found. The ATP bioluminescence method, combined with a heat shock, was investigated to determine the presence of spores in powder. The results show that only spore-containing powder samples provided a dramatic increase in the bioluminescence signal after the heat shock, which induces germination of the spores. Various conditions were tested to fi nd the most effective and rapid germination procedure. Elevated temperatures (37 degrees C and 50 degrees C) were more effective in germination than room temperature. At 50 degrees C, a double-strength germinant was more effective in germination than the regular strength. The 37 degrees C/15 min procedure induced the germination of spores most effectively, while a 50 degrees C/2 min procedure provided reasonably high signals, so it could make the entire procedure even faster (< 5 min). The detection limit of the bioluminescence method is < 100 spores.
13464037
Evaluation of nano-technology-modified zirconia oral implants: a study in rabbits.
OBJECTIVE
The objective of this study was to screen candidate nano-technology-modified, micro-structured zirconia implant surfaces relative to local bone formation and osseointegration.


MATERIALS AND METHODS
Proprietary nano-technology surface-modified (calcium phosphate: CaP) micro-structured zirconia implants (A and C), control micro-structured zirconia implants (ZiUnite), and titanium porous oxide implants (TiUnite) were implanted into the femoral condyle in 40 adult male New Zealand White rabbits. Each animal received one implant in each hind leg; thus, 20 animals received A and C implants and 20 animals received ZiUnite and TiUnite implants in contralateral hind legs. Ten animals/group were euthanized at weeks 3 and 6 when biopsies of the implant sites were processed for histometric analysis using digital photomicrographs produced using backscatter scanning electron microscopy.


RESULTS
The TiUnite surface demonstrated significantly greater bone-implant contact (BIC) (77.6+/-2.6%) compared with the A (64.6+/-3.6%) and C (62.2+/-3.1%) surfaces at 3 weeks (p<0.05). Numerical differences between ZiUnite (70.5+/-3.1%) and A and C surfaces did not reach statistical significance (p>0.05). Similarly, there were non-significant differences between the TiUnite and the ZiUnite surfaces (p>0.05). At 6 weeks, there were no significant differences in BIC between the TiUnite (67.1+/-4.2%), ZiUnite (69.7+/-5.7%), A (68.6+/-1.9%), and C (64.5+/-4.1%) surfaces (p>0.05).


CONCLUSION
TiUnite and ZiUnite implant surfaces exhibit high levels of osseointegration that, in this model, confirm their advanced osteoconductive properties. Addition of CaP nano-technology to the ZiUnite surface does not enhance the already advanced osteoconductivity displayed by the TiUnite and ZiUnite implant surfaces.
2718647
Bi-compartmental communication contributes to the opposite proliferative behavior of Notch1-deficient hair follicle and epidermal keratinocytes
Notch1-deficient epidermal keratinocytes become progressively hyperplastic and eventually produce tumors. By contrast, Notch1-deficient hair matrix keratinocytes have lower mitotic rates, resulting in smaller follicles with fewer cells. In addition, the ratio of melanocytes to keratinocytes is greatly reduced in hair follicles. Investigation into the underlying mechanism for these phenotypes revealed significant changes in the Kit, Tgfβ and insulin-like growth factor (IGF) signaling pathways, which have not been previously shown to be downstream of Notch signaling. The level of Kitl (Scf) mRNA produced by Notch1-deficient follicular keratinocytes was reduced when compared with wild type, resulting in a decline in melanocyte population. Tgfβ ligands were elevated in Notch1-deficient keratinocytes, which correlated with elevated expression of several targets, including the diffusible IGF antagonist Igfbp3 in the dermal papilla. Diffusible stromal targets remained elevated in the absence of epithelial Tgfβ receptors, consistent with paracrine Tgfβ signaling. Overexpression of Igf1 in the keratinocyte reversed the phenotype, as expected if Notch1 loss altered the IGF/insulin-like growth factor binding protein (IGFBP) balance. Conversely, epidermal keratinocytes contained less stromal Igfbp4 and might thus be primed to experience an increase in IGF signaling as animals age. These results suggest that Notch1 participates in a bi-compartmental signaling network that controls homeostasis, follicular proliferation rates and melanocyte population within the skin.
12699756
Chicoric acid: chemistry, distribution, and production
Though chicoric acid was first identified in 1958, it was largely ignored until recent popular media coverage cited potential health beneficial properties from consuming food and dietary supplements containing this compound. To date, plants from at least 63 genera and species have been found to contain chicoric acid, and while the compound is used as a processing quality indicator, it may also have useful health benefits. This review of chicoric acid summarizes research findings and highlights gaps in research knowledge for investigators, industry stakeholders, and consumers alike. Additionally, chicoric acid identification, and quantification methods, biosynthesis, processing improvements to increase chicoric acid retention, and potential areas for future research are discussed.