Biomimetic micellar mesoporous silica xerogel performs superior nitrendipine dissolution, systemic stability and cellular transmembrane transport.

To combine the advantages of micelles and biomimetic silica materials, biomimetic micellar mesoporous silica xerogel (BM-SX) was initially established, biomimetic silica xerogel (B-SX) was also studied as control and nitrendipine (NDP) was taken as model drug. The content mainly focused on drug dissolution, systemic stability and cellular transmembrane transport of NDP loaded B-SX and NDP loaded BM-SX. With extra mesopores formed due to HPMC E50 micelles, the mean pore diameter, surface area and pore volume of BM-SX were all larger than B-SX. After loading NDP into the two carriers, crystal NDP changed to amorphous phase, leading to enhanced NDP dissolution. BM-SX presented superior abilities not only for its higher drug dissolution compared to B-SX but also for its capacity in remaining high amorphous drug phase and therefore no drug dissolution reduction can be observed. The dynamic contact angle result confirmed the strong power of HPMC E50 micelles in maintaining amorphous NDP in the carrier to improve high systemic stability. Both B-SX and BM-SX could increase drug absorption permeability and exert function as drug efflux inhibitor to inhibit the efflux effect of p-gp drug pump and promote NDP absorption and transport, and BM-SX was superior owing to micelles in the system.

Elucidation of Colloid Performances of Thermosensitive In Situ-Forming Ophthalmic Gel Formed by Poloxamer 407 for Loading Drugs.

The herein work elucidated colloid performances of thermosensitive in situ-forming ophthalmic gel established by poloxamer 407 (F127), mainly including facile and simple methods (load-bearing method, tilting plate method, and eye simulation method) to analyze and evaluate F127 gel and intensively addressed capacity of F127 gel for loading drugs. The results demonstrated that the poorly water-soluble berberine hydrochloride improved entangled intensity of F127 and therefore reduced the sol dynamic rate, which contributed to lower gelation temperature and enhancement of cornea adhesion, further lowering the rate of gel corrosion together with drug release. Importantly, the addition of hydroxy propyl methyl cellulose (HPMC) K15M contributed to stronger gel strength because strong interaction forces were formed between HPMC K15M and F127 when the molecular chain segments of HPMC K15M interspersed among F127 network. All the aforementioned results provide valuable instruction for designing and evaluating thermosensitive in situ-forming ophthalmic gel.

Effects of salt stress on eco-physiological characteristics in Robinia pseudoacacia based on salt-soil rhizosphere.

Robinia pseudoacacia is the main arbor species in the coastal saline-alkali area of the Yellow River Delta. Because most studies focus on the aboveground parts, detailed information regarding root functioning under salinity is scare. Root traits of seedlings of R. pseudoacacia including morphological, physiological and growth properties under four salinity levels (CK, 1‰, 3‰ and 5‰ NaCl) were studied by the pot experiments to better understand their functions and relationships with the shoots. The results showed that seedling biomass decreased by the reduction of root, stem and leaf biomass with the increase of salinity levels. With increasing salinity levels, total root length (TRL) and total root surface area (TRSA) decreased, whereas specific root length (SRL) and specific root area (SRA) increased. Salt stress decreased root activity (RA) and the maximum net photosynthetic rate (Amax) and increased the water saturation deficit (WSD) significantly in the body. Correlation analyses showed significantly correlations between root morphological and physiological parameters and seedling biomass and shoot physiological indexes. R. pseudoacacia seedlings could adapt to 1‰ salinity by regulating the root morphology and physiology, but failed in 5‰ salinity. How to adjust the water status in the body with decreasing water uptake by roots was an important way for R. pseudoacacia seedlings to adapt to the salt stress.