In situ synthesis of TiO2/NC on cotton fibers with antibacterial properties and recyclable photocatalytic degradation of dyes.

A cotton fabric/titanium dioxide-nanocellulose (TiO2-Cot.) flexible and recyclable composite material with highly photocatalytic degradation of dyes and antibacterial properties was synthesized. During the preparation process, nano-TiO2 particles were synthesized through an in situ strategy and grown on cotton fiber, and were wrapped with cellulose nanocrystals (NC). The prepared TiO2-Cot. was characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The SEM and EDS results showed that nano-TiO2 particles were evenly distributed on the fiber surface. The prepared TiO2@Cot. has excellent photocatalytic efficiency of 95.68% for MB and 92.77% for AR under weak ultraviolet irradiation over 6 h. At the same time, it has excellent antibacterial activity against S. aureus and E. coli. The stability and reusability of the materials were also investigated.

Nitrogen-Doped Oxygenated Molybdenum Phosphide as an Efficient Electrocatalyst for Hydrogen Evolution in Alkaline Media.

Phosphides of transition metals (TMPs) are a developing class of materials for hydrogen evolution reaction (HER) as an alternative to expensive noble metals to produce clean energy. Herein, the nitrogen-doped molybdenum oxide (MoOx) is developed via a facile and simple hydrothermal method, followed by annealing in the N2 atmosphere and phosphorization to form a nitrogen-doped oxygenated molybdenum phosphide (N-MoP) sphere-shaped structure. The developed N-doped phosphide structure depicts enhanced HER activity by reaching a current density of 10 mA cm-2 at a very low overpotential of only 87 mV, which is much better than annealed nitrogen-doped molybdenum oxide (A-MoOx) 138 mV in alkaline medium. N-MoP is a highly efficient electrocatalyst for HER attributed to a more exposed surface, large electrode/electrolyte interface and appropriate binding energies for reactants. This study extends the opportunity of developing nitrogen-doped TMPs, which can display exceptional properties as compared to their oxides.

Preparation of poly(lactic-co-glycolic acid) and chitosan composite nanocarriers via electrostatic self assembly for oral delivery of insulin.

To improve insulin bioavailability and overcome multiple barriers for oral delivery of insulin, the composite nanocarriers (PLGA/FA-CS) prepared from poly(lactide-co-glycoside) (PLGA) and folic acid modified chitosan (FA-CS) were fabricated via electrostatic self-assembly method. The resultant composite nanocarriers exhibited low cytotoxicity against HT-29 cells and excellent stability against protein solution. The chemical stability of loaded insulin against digestive enzyme were established in presence of simulated gastric fluid (SGF) containing pepsin and simulated intestinal fluid (SIF) containing pancreatin, respectively. The uptake behavior of HT-29 cells was evaluated by confocal laser scanning microscope. After oral administration to the diabetic rats, an effective hypoglycemic effect was obtained compared with subcutaneous injection of insulin. This work suggests that the as-prepared composite nanocarriers may be a promising drug delivery system for oral administration of insulin and other biomacromolecules.

H2O2-Responsive mesoporous silica nanoparticles integrated with microneedle patches for the glucose-monitored transdermal delivery of insulin.

A glucose-mediated insulin delivery system would be highly satisfactory for diabetes diagnosis dependent on the concentration of blood glucose in the body. Herein, a novel microneedle (MN) delivery device integrated with insulin-loaded and H2O2-responsive mesoporous silica nanoparticles (MSNs) was designed to achieve fast and painless administration. The MSNs were obtained by the modification by 4-(imidazoyl carbamate)phenylboronic acid pinacol ester (ICBE) and following a host-guest complexation between ICBE and α-cyclodextrin (α-CD). A drug and a glucose-responsive factor, namely insulin and glucose oxidase (GOx), were encapsulated into the MSNs. GOx in the MSNs could convert glucose to gluconic acid and generate hydrogen peroxide (H2O2). The phenylboronic ester on the surface of the MSNs could be oxidized in the presence of H2O2, which resulted in the destruction of host-guest complexation, leading to the disassembly of the drug-loaded MSNs and subsequent release of the preloaded insulin. After transdermal administration to diabetic rats, an effective hypoglycemic effect was obtained by detection over time compared with that of subcutaneous injection. This work suggests that the as-prepared glucose-mediated and H2O2-responsive MN systems have promising applications in diabetes treatment.

Fabrication of biodegradable composite microneedles based on calcium sulfate and gelatin for transdermal delivery of insulin.

To reduce the inconvenience and pain of subcutaneous needle injection, the calcium sulfate and gelatin biodegradable composite microneedle patches with high aspect-ratio microneedles (MNs) and a flexible substrate have been developed. The microneedles with an aspect-ratio approximate 6:1 exhibit excellent mechanical property which can achieve 0.4N for each needle. The cross-section views show the inside of microneedles that have abundant pores and channels which offer potential for different drug-release profiles. The preparation procedures, degradable property for the biodegradable composite microneedle patches are described in the paper. Insulin, the drug to control blood glucose levels in diabetic patients, has been embedded into the biodegradable composite MNs. The hypoglycemic effect for transdermal delivery of insulin is studied using diabetic Sprague-Dawley (SD) rats as models in vivo. After transdermal administration to the diabetic rats, the released insulin from biodegradable composite MNs exhibit an obvious and effective hypoglycemic effect for longer time compared with that of subcutaneous injection route. This work suggests that biodegradable composite MNs containing of insulin have a potential application in diabetes treatment via transdermal ingestion.

Preparation of chitosan-based multifunctional nanocarriers overcoming multiple barriers for oral delivery of insulin.

To overcome multiple barriers for oral delivery of insulin, the chitosan-based multifunctional nanocarriers modified by L-valine (LV, used as a target ligand to facilitate the absorption of the small intestine) and phenylboronic acid (PBA, used as a glucose-responsive unit) have been designed and evaluated in this study. The resultant nanocarriers exhibited low cytotoxicity against HT-29 cells and excellent stability against protein solution. The insulin release behaviors were evaluated triggered by pH and glucose in vitro. The chemical stability of loaded insulin against digestive enzyme were established in presence of simulated gastric fluid (SGF) containing pepsin and simulated intestinal fluid (SIF) containing pancreatin, respectively. The uptake behavior of HT-29 cells was evaluated by confocal laser scanning microscope. After oral administration to the diabetic rats, an effective hypoglycemic effect was obtained compared with subcutaneous injection of insulin. This work suggests that L-valine modified chitosan-based multifunctional nanocarriers may be a promising drug delivery carrier for oral administration of insulin.

A composite hydrogel system containing glucose-responsive nanocarriers for oral delivery of insulin.

Development of an oral delivery strategy for insulin therapeutics has drawn much attention in recent years. In this study, a glucose-responsive nanocarriers for loading of insulin has been prepared firstly. The resultant nanocarriers exhibited relative low cytotoxicity against Caco-2 cells and excellent stability against protein solution. The insulin release behaviors were evaluated triggered by pH and glucose in vitro. In order to enhance the oral bioavailability of insulin, the insulin-loaded glucose-responsive nanocarriers were further encapsulated into a three-dimensional (3D) hyaluronic acid (HA) hydrogel environment for overcoming multiple barriers and providing multi-protection for insulin during the transport process. The hypoglycemic effect for oral delivery of insulin was studied in vivo. After oral administration to the diabetic rats, the released insulin from hydrogel systems containing insulin-loaded glucose-responsive nanocarriers exhibited an effective hypoglycemic effect for longer time compared with insulin-loaded nanocarriers.

[Comparison of clinical effects between locking intramedullary nail fixation and skeletal traction in treating tibiofibula fractures].

OBJECTIVE: To compare and evaluate clinical effects between locking intramedullary nail fixation and skeletal traction in order to provide the best therapeutic choice for tibiofibula fractures. METHODS: From November 1989 to December 2000, 108 patients with tibiofibula fractures (group A) were treated with skeletal traction, there was 76 males and 32 females; the age was from 29 to 66 years with an average of (40.3 +/- 9.6) years; according to AO classification standard,48 cases were type A, 46 type B, 14 type C, of which the standard typing Gustio, type I in 15 cases, type II in 13, type III A in 2. And from January 2001 to July 2007, 57 patients with tibiofibula fractures (group B) were treated with locking intramedullary nail fixation,there was 40 males and 17 females,the age was from 21 to 69 years with an average of (38.1 +/- 8.9) years; according to AO classification standard, 27 cases were type A, 22 type B, 8 type C, of which the standard typing Gustio, type I in 7 cases, type II in 6, type III A in 1. Four indexes were compared, including the time of fracture healing, the time of achieved 90 degrees genuflection, the time of off-bed weight-bearing and complication. RESULTS: Comparison of fracture healing time: group A was (19.0 +/- 0.6) weeks and group B was (14.0 +/- 0.5) weeks; the time of achieved 90 degrees genuflection in group A was (92.0 +/- 8.2) d and in group B was (39.0 +/- 6.1) d; the time of off-bed weight-bearing in group A was (96.0 +/- 6.3) d and in group B was (38.0 +/- 6.5) d. Complication occurred in 42 cases in group A and 6 in group B. There was significantly difference in 4 items between two groups (P < 0.01). The method of locking intramedullary nail fixation was better than skeletal traction in treating tibiofibula fractures. CONCLUSION: Treatment of tibiaofibula fractures with locking intramedullary nail fixation can obtain satisfactory effect, which has less complication, the fracture heals and weigh-loading can be achieved early.