Drug-loaded PLCL/PEO-SA bilayer nanofibrous membrane for controlled release.

The bilayer nanofibrous membrane fabricated via electrospinning technique can be considered as an ideal structure for the treatment of chronic skin diseases and exudative wound dressings. Wound exudate would affect healing and increases the likelihood of infection at the same time. Therefore, it is essential to produce a kind of wound dressing with relatively high hygroscopicity which could absorb wound exudate and provide a relatively dry healing environment. Bilayer nanofibrous membranes of poly(L-lactide-co-ε-caprolactone)/tetracycline hydrochloride- polyethylene oxide/sodium alginate-zinc oxide (PLCL/TCH-PEO/SA-ZnO) with drug delivery potential were prepared by electrospinning for wound healing. Then, a cross-linking which involved soaking the samples in an aqueous solution containing strontium ions for 4 h was conducted. SEM images showed that membranes still maintained the peculiar nanofibrous structure. The spinning aid (PEO) used was removed in the cross-linked alginate without affecting the PLCL/TCH outer layer gave the membrane good mechanical properties and manageability. The hydrophilicity of the mats was tested to evaluate the ability of the bilayer membrane to absorb exudate from the wound. In vitro drug release suggested that antibacterial agents TCH could release continuously more than 10 days. The cross-linked fibrous membrane has improved mechanical properties and fluid repellency, thus representing a barrier to the external environment and effective wound protection. Consequently, the bilayer fibrous scaffold with good hygroscopicity and drug release properties would have wide applications prospects for the treatment of chronic skin diseases and exudative wound dressings.

BSA loaded bead-on-string nanofiber scaffold with core-shell structure applied in tissue engineering.

Beaded nanofiber is a promising fibrous structure could act as drug delivery system with sustained drug release for regulating cell behaviors used in tissue engineering. Poly (L-lactic acid-co-ε-caprolactone) (PLCL) beaded nanofiber with core-shell structure (130 ± 30 nm) was fabricated and bovine serum albumin (BSA) was encapsulated into the inner layer. The surface morphology and characteristic were evaluated by scanning electron microscopy (SEM), inverted fluorescence microscopy and water contact angle test. Degradation analyses suggested that PLCL/BSA core-shell @ beaded nanofibers could maintain the fibrous framework during 3 weeks. The biocompatibility was investigated by in vitro cultivation of human mesenchymal stem cells (hMSCs) on the surface of PLCL/BSA core-shell @ beaded nanofibers. The proliferation of hMSCs was tested using alamar blue reagent and the spreading morphology of cells was observed by SEM. Corresponding results suggested that beaded nanofibers with core-shell structure could effectively support the attachment and proliferation of cells. PLCL beaded nanofiber with core-shell structure would work as a promising candidate for drug release system and tissue engineering.

Preparation and characterization of wormwood-oil-contained microcapsules.

In recent years, wormwood has been successfully applied in various fields, such as flavouring agent, plant dye, insect repellent and medical product. Wormwood oil encapsulated microcapsules with continuous release behaviours would be further applied in the health care textiles. Here, wormwood oil encapsulated microcapsules with different core-wall materials ratios (gelatine: gum arabic: wormwood oil = 1:1:1, 1:1:2, 1:1:3, 1:1:4) were fabricated. The morphology and physicochemical properties of microcapsules were explored by scanning electron microscopy, ultrasonic wave particle size analysis, thermo gravimetric analysis and so on. The size analysis results indicated that the microcapsule diameter could be controlled less than 1 um. In vitro testing showed that the microcapsules were capable of extending the releasing period to over 6 days. The thermo gravimetric analysis proved that microcapsules had superior thermal stability compared with pure wormwood oil, showing broad application prospects in functional health care textile.

Solid drug particles encapsulated bead-on-string nanofibers: the control of bead number and its corresponding release profile.

Bead-on-string nanofibers are explored as potential carriers of micro-level solid drug particles in recent years in drug release and tissue engineering. The special alternating distribution of nanoscale fiber and micro beads satisfied the fully encapsulation of particle drugs and the corresponding sustained release. Antibiotic drug tetracycline hydrochloride (TCH) was used as solid model drug particles. The present study fabricated poly (lactic-co-glycolic acid) (PLG A) bead-on-string nanofibers with different TCH loading rates for the controlled drug delivery. Bead number (BN), as one of the crucial factors that determine the encapsulation capability, was successfully controlled by tailoring the electrospinning parameters: voltage, flow rate and distance. The in vitro release experiment analyze by UV-Visible light spectrophotometer indicated that the bead-on-string nanofiber with more BN would increase the total release quantity of TCH. The drug released from bead-on-string nanofibers was mainly driven by classical Fickian diffusion. PLGA bead-on-string nanofibers suggest the potential as promising substrate for solid drug particles delivery applications.

Fabrication, mechanical property and in vitro evaluation of poly (L-lactic acid-co-ε-caprolactone) core-shell nanofiber scaffold for tissue engineering.

Coaxial electrospinning, in which Poly (L-lactic acid-co-ε-caprolactone) (PLC) with different Lactic acid (LA) to caprolactone (CL) ratio (75:25 and 50:50) were employed to electrospin core-shell nanofibers which could mimic the native extracellular matrix for tissue engineering applications. Core-shell nanofibrous scaffolds of PLC (50:50)/BSA (426 ±â€¯157 nm) and PLC (75:25)/BSA (427 ±â€¯197 nm) were fabricated and model drug bovine serum albumin (BSA) was entrapped in the core layer. The morphology, core-shell structure and sustained release behaviors were evaluated by Scanning electron microscopy (SEM), transmission electron microscopy (TEM), inverted fluorescence microscopy, water contact angle test and in vitro release test, respectively. The effect of core-shell structure and shell layer materials on the variation tendency of mechanical characterization in dry and wet situation were also investigated by tensile testing. The in vitro biocompatibility of scaffolds were investigated by growing human mesenchymal stem cells (hMSCs) on scaffolds surface and the proliferation of cells were evaluated with Alamar Blue tests. In vitro cultivations of hMSCs showed that PLC (50:50)/BSA scaffolds supported a significantly higher proliferation rate of seeded cells than scaffolds prepared by polymer PLC (75:25)/BSA. Overall, the PLC core-shell nanofibers possessed potentially regulable mechanical properties useful for tissue engineering as well as sustained release potential for medical applications.

[Correlation of IgG Subclass with Blood Cell Parameters in Patients with Autoimmune Hemolytic anemia].

OBJECTIVE: To investigate the correlation of IgG subclasses with blood cell parameters in the patients with autoimmune hemolytic anemia (AIHA). METHODS: Thirty-four patients with AIHA (except C3d types) of immune complex type (IgG+C3d) and single IgG type, including 26 cases of primary AIHA and 8 cases of secondary AIHA from December 2010 to August 2016 in our hospital were selected and enrolled in AIHA group; 30 healthy persons were selected and enrolled in healthy control group. The levels of IgG subclasses in blood plasma were detected by double antibody sandwich ELISA in healthy persons and AIHA patients, at the same time. The levels of IgG subclasses in of RBC diffuse fluid were detected as well. The relation of IgG subclass level with some parameters of blood cells was analyzed in the hight of partial parameters of blood cells in patients. The independent sample test was used for comparison of data in 2 groups, the Spearman method was used for correlation analyziz. RESULTS: The average value of IgG1-4 in AIHA group was higher than that in healthy control group, there was statisticad difference between 2 groups (IgG1: t=-4.88, P<0.01; IgG2: t=-3.06. P<0.01; IgG3: t=-5.39, P<0.01; IgG4: t=-3.16, P<0.01), but the comparison of various. IgG subclass ratio in 2 groups showed that in addition to IgG4 (t=1.73, P >0.01) the ratio pf IgG1, IgG2 and IgG3 all had the statistical differences (IgG1: t=4.03, P<0.01; IgG2: t=7.38, P<0.01; IgG3: t=3.03, P<0.01). The spearmen analysis of corrclation of IgG subclass in blood plasma of patients with partial parameters of blood cells showed that the IgG4 positivety correlated with Hb level, the RBC count and HCT (Hb: r=0.358, P<0.05; RBC: r=0.426, P<0.05; HCT: r=0.363, P<0.05); the IgG1 and IgG2 negatively correlated with WBC count (IgG1: r=0.437, P<0.05; IgG2: r=-0.487, P<0.01); the IgG2 negatively correlated with count (r=-0.436, P<0.05). The comparison of IgG subclass ratio in plasma and RBC diffuse fluid of patients showed that in addition to IgG2 (t=1.544, P＞0.05), the rest IgG1, 3 and 4 all had statistical differences (IgG1: t=6.528, P<0.01; IgG3: t=-9.488, P<0.05; IgG4: t=-9.434, P<0.05). CONCLUSIONS: The AIHA relates with IgG1 and IgG3, the detection of IgG subclasses may have a certain significance for studying the diagnosis, treatment and pothogenesis of AIHA.

The control of beads diameter of bead-on-string electrospun nanofibers and the corresponding release behaviors of embedded drugs.

Bead-on-string nanofibers, with appropriate control of the beads diameter, are potential fibrous structures for efficient encapsulation of particle drugs in micron scales and could achieve controlled drug release for tissue engineering applications. In this study, the beads diameter of electrospun bead-on-string nanofibers was controlled by adjusting the concentration of spinning polymer, poly (lactic-co-glycolic acid) (PLGA), and the solvent ratio of chloroform to acetone. The images of the scanning electron microscopy (SEM) suggested that bead-on-string nanofibers could be successfully obtained only with a certain range of PLGA solution concentration. Moreover, with the decrease in the solvent ratio of chloroform to acetone, the range was left-shifted towards a smaller concentration. In addition, increase in the PLGA solution concentration within the range the beads diameter became greater and the shape of the beads changed from oval to slender when increasing the PLGA concentration within the range. The bead-on-string nanofibers with different beads diameter were further used to load micro-particle drugs of tetracycline hydrochloride, as a model drug, to examine the release behavior of nanofibers scaffold. The release profiles of drug loaded bead-on-string nanofibers demonstrated the possibility to alleviate the burst drug release by means of beads diameter control.