Preformulation, Characterization, and In Vitro Release Studies of Caffeine-Loaded Solid Lipid Nanoparticles

Encapsulation of active agents in solid lipid nanoparricles (SLNs) is an alternative to other controlled release systems for topical delivery. In this study, caffeine was encapsulated in SLNs to produce a delivery system with controlled release. Caffeine-loaded SLNs (Caf-SLNs) were prepared using the double emulsion method with homogenization and ultrasonication. The characterization studies were performed using dynamic light scattering (DLS), zeta potential, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) analyses. The encapsulation efficiency rests were performed using UV spectrophorometry. In vitro release studies were conducted using a dialysis bag technique and high-performance liquid chromatography (HPLC) for the quantification of caffeine (Caf). The results from the DLS analysis showed that all formulations had a polydispersity index <0.3 with particle sizes <210 nm. The DSC and SEM results showed that Caf was dispersed in the SLNs. The encapsulation efficiency was 49.22%. The release studies indicated that after an initial burst at 3 min, the SLNs released Caf in a controlled manner over a 6-h period. Taken together, the SLNs can be used as a carrier for the topical delivery of Caf

Variable sonographic spectrum of parathyroid adenoma with a novel ultrasound finding: dual concentric echo sign

WOS: 000355378000002PubMed ID: 26052562Aims: To review the detailed gray-scale and Doppler ultrasonography features of histologically proven parathyroid adenomas (PAs) evaluated with high-end ultrasonography devices and to present a novel ultrasonography finding called the dual concentric echo sign in PA with histopathologic correlation which was encountered during detailed analysis. Material and methods: Fifty-six PAs with histopathological result were enrolled. The longest dimension, shape, distance to skin surface, internal echo and Doppler US features obtained with high-end US devices were evaluated. Results: PAs had variable range of shape including oval, irregular, fusiform, lobulated, crescent-shaped, and nodular configuration. In nine patients the lesions were shown to have cystic components and calcifications were seen in four cases. Dual concentric echo sign was detected in 18% PAs. Histological reevaluation of this subgroup demonstrated significantly increased edema (p<0.01), and ectatic vessels (p=0.02) in the central part of the lesion compared to the rest of the PAs. Conclusions: The results of the study led to the conclusion that PAs have variable gray-scale and Doppler findings. Typical sonographic features like ovoid shape, homogeneously hypoechoic pattern may not be present in all PAs. Dual concentric echo sign which is a novel sonographic pattern may be suggestive of a PA

Variable sonographic spectrum of parathyroid adenoma with a novel ultrasound finding: dual concentric echo sign

Abstract Aims: To review the detailed gray-scale and Doppler ultrasonography features of histologically proven parathyroid adenomas (PAs) evaluated with high-end ultrasonography devices and to present a novel ultrasonography finding called the dual concentric echo sign in PA with histopathologic correlation which was encountered during detailed analysis. Material and methods: Fifty-six PAs with histopathological result were enrolled. The longest dimension, shape, distance to skin surface, internal echo and Doppler US features obtained with high-end US devices were evaluated. Results: PAs had variable range of shape including oval, irregular, fusiform, lobulated, crescent-shaped, and nodular configuration. In nine patients the lesions were shown to have cystic components and calcifications were seen in four cases. Dual concentric echo sign was detected in 18% PAs. Histological reevaluation of this subgroup demonstrated significantly increased edema (p&lt;0.01), and ectatic vessels (p=0.02) in the central part of the lesion compared to the rest of the PAs. Conclusions: The results of the study led to the conclusion that PAs have variable gray-scale and Doppler findings. Typical sonographic features like ovoid shape, homogeneously hypoechoic pattern may not be present in all PAs. Dual concentric echo sign which is a novel sonographic pattern may be suggestive of a PA

A comparative study of the effects of gutta-percha solvents on human osteoblasts and murine fibroblasts

We aimed to investigate the in vitro physiologic effects of xylene, chloroform, orange oil and eucalyptus oil solvents for dissolving gutta-percha on L929 and HOB cell lines; 2.5 and 10 mu L mL(-1) of these solvents were tested for 24, 48 and 72 h. Gutta-percha solvents inhibited the proliferation rate of fibroblasts in a dose- and time-dependent manner; however, no inhibition was detected in HOB (evaluated using MTT assay). None of the solvents induced apoptosis/necrosis in HOB cells at <= 2.5 mu L mL(-1) concentration in contrast to L929 (determined using acridine orange/ethidium bromide dual staining). Each solvent tested reduced the migration rate of both L929 and HOB cell lines in a dose-dependent manner (evaluated using a scratch assay). Gutta-percha solvents can damage fibroblast-rich tissues. Osteoblasts seemed to be more resistant to the tested solvents, and excessive extrusion of solvents from the root canal may also damage the periradicular tissues and reduce the ability to repair

Production of Small, Stable PbS/CdS Quantum Dots via Room Temperature Cation Exchange Followed by a Low Temperature Annealing Processes

Here, we discuss a simple low temperature process for the synthesis of small and stable PbS/CdS QDs with emission below 1100 nm. For this, small PbS QDs with emission below 1100 nm synthesized from PbCl₂ in oleylamine with 1-dodecanethiol, as reported by our group recently, were used. A thin CdS shell was grown on PbS at room temperature (RT) via cation exchange (CE), which is a self-limiting process providing about 100 nm blue shift in the emission maxima, hence is quite practical for reaction control and production of predictable particles. RTCE process provides 6–9 times stronger emission than original PbS with better optical stability. Annealing of the PbS/CdS QDs in solid state at mild temperatures (50–100 °C) improves crystallinity of the particles. Final ligand exchange on the annealed PbS/CdS with 1-dodecanethiol (DT) enhances the long-term stability of particles further. The optimum overall process is determined as RTCE followed by annealing at 50 °C for 1 h and finished with ligand exchange with DT. Influence of these processes on QD structure and optical properties were studied as well as stability in chloroform and petroleum products (diesel and gasoline) for possible optical tagging applications of such liquids. Overall, a simple, controllable, and scalable method is developed to produce highly stable, bright, size-tunable PbS/CdS QDs with emission detectable with low cost semiconductor detectors