Preparation of long-acting microspheres loaded with octreotide for the treatment of portal hypertensive.

The purpose of this study was to optimize the preparation method of injectable Octreotide microspheres. To explore the correlation between the solvent system and the general properties of microspheres to reduce burst release and enable them to be used for portal hypertension. Octreotide microspheres were prepared by modified double emulsion solution evaporation method after optimizing preparation conditions. The results showed that Octreotide microspheres had a particle size of 57.48 ± 15.24 µm, and the initial release was significantly reduced. In vitro release and in vivo pharmacokinetic data indicated that Octreotide was released stably within 1200 h. The effects on portal vein pressure, liver tissue morphology and other related indexes were observed after administration. As obvious results, injection of Octreotide microspheres could significantly reduce portal vein pressure and reduce the portal vein lumen area in experimental cirrhotic portal hypertensive rats. The optimized Octreotide PLGA microsphere preparation has been proved to have a good effect on PHT in vivo after detecting aminotransferase (AST) and alanine aminotransferase (ALT) activity, liver tissue hydroxyproline (Hyp) content, serum and liver tissue malondialdehyde (MDA) levels, plasma prostacyclin (PGI2) levels, and liver tissue tumor necrosis factor (TNFα) content. In addition, serum and liver tissue superoxide dismutase (SOD) activity and liver tissue glutathione (GSH) content, plasma thromboxane (TXA2), serum nitric oxide (NO), liver tissue nitric oxide synthase (NOS), and plasma and liver tissue endothelin (ET) were significantly increased.

Facile synthesis and characterization of novel rapid-setting spherical sub-micron bioactive glasses cements and their biocompatibility in vitro.

Dental pulp vitality is extremely important for the tooth viability, since it provides nutrition and forms the dentin. Bioactive glasses (BGs) may be promising materials for pulp repair due to their excellent abilities of rapidly bonding to bone and stimulating new bone growth. However, the unsatisfied handling property, low plasticity, and poor rapid-setting property of traditional BGs limit its application in vital pulp therapy. Spherical bioactive glasses (SBGs) exhibited higher osteogenesis and odontogenic differentiation than irregular BGs. This study focuses on the application of SBGs with rapid setting property for dental pulp repair. Here, SBGs with various compositions were successfully synthesized by a sol-gel process using dodecylamine (DDA) served as both a catalyst and a template. The maximum content of CaO in SBGs was about 15%. The non-bridge oxygen amounts of the SiO network and the apatite-forming ability increased with the content proportion of CaO and P2O5. Bioactive glass pulp capping materials (BGPCMs) were prepared by mixing the SBGs powders and the phosphate buffer solution (PBS). The K3CaH(PO4)2 and hydroxyapatite (HA) formed between SBGs particles as soon as they were mixed with PBS solution. The compressive strengths of fully set BCPCM-2 molded were measured to be 31.76±1.9577MPa after setting for 24h. The K3CaH(PO4)2 and the low crystallinity HA phases at the initial stage of solidification transformed to crystalline HA for 3days, and the compressive strength was still higher than 10MPa. Additionally, SBG-2 with a designed molar composition of 35% SiO2, 55% CaO and 10% P2O5 more promoted dental pulp cell proliferation, and could be potential pulp capping applications.

Evaluation of Pulp Response to Novel Bioactive Glass Pulp Capping Materials.

INTRODUCTION: This study aimed to investigate dental pulp responses to novel bioactive glass (BG) pulp capping materials after direct pulp capping in vivo. METHODS: Novel BG pulp capping materials are composed of powder and fluid. The powder is BG (82.36% SiO2, 15.36% CaO, and 2.28% P2O5), and the fluid is provided in 2 kinds: (1) phosphate buffer solution (BG-PB) and (2) phosphate buffer solution with the addition of 1 wt% sodium alginate (BG-PB-SA). After mixing the powder and fluid, BG-PB and BG-PB-SA were prepared. Cavities with mechanical pulp exposure were prepared on maxillary first molars of Wistar rats. The exposures were randomly capped with BG-PB, BG-PB-SA, or mineral trioxide aggregate (MTA). After 1 (n = 6) and 4 weeks (n = 8), maxillary segments were obtained and prepared for histologic analysis with a scoring system. Statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney U tests with the significance set at .05. RESULTS: After 1 week, few inflammatory cells were present in the BG-PB, BG-PB-SA, and MTA groups. Moreover, a thin layer of newly generated matrix was observed in most specimens. After 4 weeks, all specimens from the 3 groups formed a heavy dentin bridge. BG-PB and BG-PB-SA groups exhibited no or slight inflammatory response, whereas the MTA group exhibited a slight to moderate inflammatory response. No significant difference was observed in pulp inflammation and dentin formation among the 3 groups at either time point (P > .05). CONCLUSIONS: When used as a pulp capping agent, BG-PB and BG-PB-SA had similar favorable cellular and inflammatory pulp responses to those of MTA. Therefore, BG is a promising pulp capping material.

Cationic Polyarginine Conjugated Mesoporous Bioactive Glass Nanoparticles with Polyglycerol Coating for Efficient DNA Delivery.

Mesoporous bioactive glass (MBG) is a type of material with high biological activity and excellent biocompatibility. Because of its high specific surface area and adjustable surface morphology, MBG is usable for loading and delivering molecules. In our previous report, MBG particles were used as gene vectors and showed good transfection rate. In this paper, MBG, prepared through a sacrificial liquid template method in sol­gel process, was covered with polyglycerol (PG) and the resulting MBG-PG was further functionalized with octaarginine (Arg8. More specifically, MBG-PG-Arg8 particles were synthesized by PG functionalization of MBG through ring-opening polymerization of glycidol on the MBG surface, followed by multistep organic transformations (­OH→ ­OTs (tosylate)→ ­N3 in the PG layer and click conjugation of the Arg8 terminated with propargyl glycine. MBG-PG-Arg8 was successfully taken up by cells more efficiently due to the cellpenetrating property of Arg8, and thus showed higher plasmid DNA loading and cell transfection efficiency than MBG modified with amino groups. This novel arginine-functionalized MBG may be a good candidate as a vector for gene delivery with higher efficiency.