Rapidly stopping hemorrhage by enhancing blood clotting at an opened wound using chitosan/polylactic acid/polycaprolactone wound dressing device

Doxycycline and monosodium glutamate (MSG) loaded chitosan (CHI)/polylactic acid (PLA)/polycaprolactone (PCL) blend film was studied as a model device to deliver drug to targeted human organ which in this case was the skin with opened wound. The CHI/PLA/PCL blend film containing 60 % CHI, 28 % PLA, and 12 % PCL exhibited the good properties for making the dressing device. It was observed that doxycycline/MSG loaded CHI/PLA/PCL blend film could rapidly deliver both doxycycline and MSG at the high release percentage approaching 100 % loaded. MSG accelerated blood clotting and fibrin formation; thus, it exhibited the good hemostatic activity. The antibacterial activity of doxycycline loaded CHI/PLA/PCL blend film against Staphylococcus aureus and Escherichia coli as model bacteria was investigated. Doxycycline release played the crucial role in bacterial inhibition as observed from the lowest bacterial cell dry weight observed when compared with the control bacterial culture or the bacterial cultures with the presence of other films studied.     

Anti-osteoclastogenic,estrogenic, and antioxidant activities of cell suspension cultures and tuber root extracts from Pueraria mirifica

The flavonoid contents of intact tubers and cell culture media were determined and physiological activities of Pueraria mirifica extracts were investigated. The total flavonoid contents from cell culture media (PMC) were higher than from tubers (PMT). Results from in vivo estrogenic activity assays indicated that PMT had a strong estrogenic activity in ovariectomized rats. The same amount of PMC exhibited a weak activity. In vitro osteoclast suppression investigations indicated that both PMT and PMC extracts exhibited anti-osteoclastogenic activities with low toxicities in a standard test cell line. Determination of the antioxidant potential using the DPPH assay revealed that the IC₅₀ value for PMT was lower than for PMC. P. mirifica cell cultures produce more flavonoids and exhibit a mild estrogenic and more antioxidant activities than tubers.     

Syntheses,characterization, and antibacterial activity of chitosan grafted hydrogels and associated mica‐containing nanocomposite hydrogels

Chitosan (CS) grafted poly[(acrylic acid)‐co‐(2‐hydroxyethyl methacrylate)] (CS‐g‐poly(AA‐co‐HEMA)) at different molar ratios of AA and HEMA, and the associated nanocomposite hydrogels of CS‐g‐poly(AA‐co‐HEMA)/mica were synthesized by radical copolymerization. The grafting positions at the amino or hydroxyl groups in the CS were identified by Fourier transform infrared spectroscopy. CS‐g‐poly(AA‐co‐HEMA) hydrogels were intercalated in the mica and the amount of hydrogel insertion did not affect the spacing of the silicate layers in mica. The higher mica loadings produced a rougher surface of the nanocomposite hydrogel. The water absorbency of the CS‐g‐poly(AA‐co‐HEMA)/mica nanocomposite hydrogels decreased with increasing levels of mica loading to a lower level than those of the CS‐g‐poly(AA‐co‐HEMA) hydrogels. Both CS‐g‐poly(AA) and CS‐g‐poly(AA‐co‐HEMA)/mica nanocomposite hydrogels exhibited a higher antiproliferative activity against Staphylococcus aureus than did the neat CS hydrogel with CS‐g‐poly(AA) revealing a very pronounced minimum inhibition concentration (MIC) of 1.56 mg mL^?1. The extent of mica loading in the CS‐g‐poly(AA‐co‐HEMA) nanocomposite hydrogels did not affect the MIC (12.5 mg mL^?1). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Shear Stress Enhances the Paracrine-Mediated Immunoregulatory Function of Human Periodontal Ligament Stem Cells via the ERK Signalling Pathway

Relevant immunomodulatory effects have been proposed following allogeneic cell-based therapy with human periodontal ligament stem cells (hPDLSCs). This study aimed to examine the influence of shear stress on the immunosuppressive capacity of hPDLSCs. Cells were subjected to shear stress at different magnitudes (0.5, 5 and 10 dyn/cm2). The expression of immunosuppressive markers was evaluated in shear stress-induced hPDLSCs using qRT-PCR, western blot, enzyme activity and enzyme-linked immunosorbent assays. The effects of a shear stress-derived condition medium (SS-CM) on T cell proliferation were examined using a resazurin assay. Treg differentiation was investigated using qRT-PCR and flow cytometry analysis. Our results revealed that shear stress increased mRNA expression of IDO and COX2 but not TGF-β1 and IFN-γ. IDO activity, kynurenine and active TGF-β1 increased in SS-CM when compared to the non-shear stress-derived conditioned medium (CTL-CM). The amount of kynurenine in SS-CM was reduced in the presence of cycloheximide and ERK inhibitor. Subsequently, T cell proliferation decreased in SS-CM compared to CTL-CM. Treg differentiation was promoted in SS-CM, indicated by FOXP3, IL-10 expression and CD4+CD25hiCD127lo/− subpopulation. In conclusion, shear stress promotes kynurenine production through ERK signalling in hPDLSC, leading to the inhibition of T cell proliferation and the promotion of Treg cell differentiation.     

Comparison of an Ion Exchanger and an In‐House Electrodialysis Unit for Recovery of L‐Lactic Acid from Fungal Fermentation Broth

Lactic acid has long been widely used in many applications. Currently, the worldwide market is increasing due to the discovery of biodegradable polylactic acid. In this work, L‐lactic acid separations from filamentous fungal fermentation broth using ion‐exchange chromatography and in‐house electrodialysis, were studied and compared. Dowex Marathon WBA was used for the lactic acid separation. The adsorption equilibrium followed a Langmuir isotherm. The optimal conditions for lactic acid adsorption in a fixed‐bed column were at pH 6.0, and 0.8 mL/min and elution by a mixture of 1.0 M sulfuric acid and 1.0 M phosphoric acid in a ratio of 30:70 at 0.3 mL/min. The final lactic acid recovery was 76 % with 90 % purity. A laboratory scale in‐house electrodialysis apparatus was constructed with an effective membrane area of 2.925 · 10^–3 m². The effects of feeding solution concentration, flow rate, pH of the fermentation broth, and applicable voltage were studied. Under the optimal conditions, lactic acid recovery was 92 % with 100 % purity and a specific energy consumption of 0.6122 kWh/kg.