Synthesis and Cathodoluminescence of β-Ga₂O₃ Nanowires with Holes

Abstract

CyA was prepared into CyA Eudragit S100 nanoparticles (CyA-S100 NP) and the mechanisms of CyA-S100 NP improving the CyA absorption in gastrointestinal tract (GI) were studied systematically in rats. In the GI distribution study, the emptying rates of CyA-S100 NP in duodenum, jejunum, ileum and colon were all lower than these of Neoral, while in stomach, it was larger than that of Neoral. In in situ recirculating intestine perfusion experiment, the largest absorption in CyA-S100 NP group occurred in ileum while that in Neoral group arised in duodenum. The sequence of (AUC0-240 min)/A for CyA-S100 NP and Neoral group was ileum > duodenum > jejunum > colon and duodenum > jejunum > ileum > colon, respectively. CyA in nanoparticles degradated by luminal contents and subcellular fractions were more slowly than these in Neoral, suggesting the significant protect effect of nanoparticles. Mucoadhesion study in small intestine showed that among all the parts of intestine, CyA-S100 NP exhibited larger mucoadhesive characteristics than Neoral microemulsion. The sequence of mucoadhesion for CyA-S100 NP group was duodenum > ileum > jejunum and colon, while that for Neoral group was duodenum > ileum, jejunum and colon, suggesting different site-specific behaves. These results illustrated that nanoparticles increased the absorption of CyA could be attributed to fast stomach empting rate, absorption site specific, small degradation rate by luminal contents, high bioadhension of nanoparticles to intestine mucosa and the use of P-Glycoprotein inhibitor if there is any. This investigation is helpful for the dosage form design for other peptide or protein drugs.

Developments in Methods for Measuring the Intestinal Absorption of Nanoparticle-Bound Drugs

“…The intestinal segments are exposed by making a 3 cm incision along the abdominal cavity through the ventral midline, and two medical silicone tubes are cannulated at both ends of the intestine. The upper tube is connected with the peristaltic pump to import the perfusion fluid, while the lower tube is used to export the perfusion fluid as shown in Figure 7 [ 62 ]. The incision is then covered with absorbent cotton saturated with physiological saline and warmed with infrared light.…”

pH-Responsive carriers for oral drug delivery: challenges and opportunities of current platforms

“…Multi-ion-crosslinked NPs had a superior stability over a broader pH range than NPs, and significantly more effectively transported insulin than NPs, suggesting that multi-ion-crosslinked NPs are a promising carrier for improved transmucosal delivery of insulin in the small intestine (Lin et al, 2008 ). pH-Responsive nanomatrix system of CyA with Sylysia 350 and Eudragit® attenuated the potential nephrotoxicity caused by the pronounced initial plasma peak of Neoral®, as well as enhanced the oral absorption of CyA and improved the relative bioavailabilities to 162.1% compared with Neoral, which could be attributed to fast stomach empting rate, absorption site specific, small degradation rate by luminal contents, high bioadhension of pH-responsive NPs to intestine mucosa and the use of P-Glycoprotein inhibitor if there is any (Wang et al, 2008 ). Examples of bioavailability improvement of insulin and CyA after orally administrating of different pH-responsive carrier are summarized in Table 3 .…”

A silica-based pH-sensitive nanomatrix system improves the oral absorption and efficacy of incretin hormone glucagon-like peptide-1

“…The permeability of SPN-GLP-1 against a biomembrane were examined using a model of a human colon adenocarcinoma (Caco-2) cell line (ATCC, passage number: [30][31][32][33][34]. Briefly, the cells were grown until 80% confluence and seeded onto the collagen-coated polycarbonate.…”