Influence of poly(n‐isopropylacrylamide)–CNT–polyaniline three‐dimensional electrospun microfabric scaffolds on cell growth and viability

This study investigates the effect on: (1) the bulk surface and (2) the three‐dimensional non‐woven microfabric scaffolds of poly(N‐isopropylacrylamide)–CNT–polyaniline on growth and viability of cells. The poly(N‐isopropylacrylamide)–CNT–polyaniline was prepared using coupling chemistry and electrospinning was then used for the fabrication of responsive, non‐woven microfabric scaffolds. The electrospun microfabrics were assembled in regular three‐dimensional scaffolds with OD: 400–500 μm; L: 6–20 cm. Mice fibroblast cells L929 were seeded on the both poly(N‐isopropylacrylamide)–CNT–polyaniline bulk surface as well as non‐woven microfabric scaffolds. Excellent cell proliferation and viability was observed on poly(N‐isopropylacrylamide)–CNT–polyaniline non‐woven microfabric matrices in compare to poly(N‐isopropylacrylamide)–CNT–polyaniline bulk and commercially available Matrigel? even with a range of cell lines up to 168 h. Temperature dependent cells detachment behavior was observed on the poly(N‐isopropylacrylamide)–CNT–polyaniline scaffolds by varying incubation at below lower critical solution temperature of poly(N‐isopropylacrylamide). The results suggest that poly(N‐isopropylacrylamide)–CNT–polyaniline non‐woven microfabrics could be used as a smart matrices for applications in tissue engineering. © 2012 Wiley Periodicals, Inc. Biopolymers 99: 334–341, 2013.     

Synthesis and biological evaluation of a novel series of aryl S,N-ketene acetals as antileishmanial agents

A series of aryl S,N-ketene acetals 7(a–f) was synthesized and evaluated for their in vitro and in vivo antileishmanial activity against Leishmania donovani. All the 6 compounds exhibited significant in vitro activity against intracellular amastigotes of L. donovani with IC₅₀ values ranging from 1.2 to 3.5 μM and were found promising as compared with reference drugs, sodium stibogluconate (SSG) and paromomycin. On the basis of good selectivity indices (SI), they were further tested for their in vivo potential against L. donovani/hamster model. Two compounds 7a and 7b showed significant inhibition of parasite multiplication, 72% and 83%, respectively. These compounds were comparable with SSG and superior to paromomycin. Preliminary in vitro metabolic investigations were also performed to assess the metabolic stability and in vitro hepatic intrinsic clearance (Cl_int) of compound 7b in hamster liver microsomes.     

Morphological specializations of the buccal cavity in relation to the food and feeding habit of a carp Cirrhinus mrigala: A scanning electron microscopic investigation

The buccal cavity of an herbivorous fish, Cirrhinus mrigala, was investigated by scanning electron microscopy to determine its surface ultrastructure. The buccal cavity shows significant adaptive modifications in relation to food and feeding ecology of the fish. The buccal cavity of the fish is of modest size and limited capacity, which is considered an adaptation with respect to the small‐sized food items primarily consumed by the fish that could be accommodated in a small space. Modification of surface epithelial cells, on the upper jaw, into characteristic structures—the unculi—is considered an adaptation to browse or scrap, to grasp food materials, e.g., algal felts, and to protect the epithelial surface against abrasions, likely to occur during their characteristic feeding behavior. Differentiation of the highly specialized lamellar organ on the anterior region of the palate could be an adaptation playing a significant role in the selection, retention, and sorting out of palatable food particles from the unpalatable items ingested by the fish. The filamentous epithelial projections and the lingulate epithelial projections on the palatal organ in the posterior region of the palate are considered to serve a critical function in final selection, handling, maneuvering, and propelling the food particles toward the esophagus. The abundance of different categories of taste buds in the buccal cavity suggests that gustation is well developed and the fish is highly responsive in the evaluation and the selection of the preferred palatable food items. The secretions of mucous cells in the buccal cavity are associated with multiple functions—particle entrapment, lubrication of the buccal epithelium and food particles to assist smooth passage of food, and to protect the epithelium from possible abrasion. These morphological characteristics ensure efficient working of the buccal cavity in the assessment of the quality and palatability of ingested food, their retention and transport toward the esophagus. Such an adaptation may be essential in conducting the function most basic to the survival of the individuals and species—feeding. J. Morphol. 2009. © 2009 Wiley‐Liss, Inc.     

HSP47 regulates ECM accumulation in renal proximal tubular cells induced by TGF-β1 through ERK1/2 and JNK MAPK pathways

Heat shock protein (HSP)47 is a collagen-specific molecular chaperone that is essential for the biosynthesis of collagen molecules. It is likely that increased levels of HSP47 contribute to the assembly of procollagen and thereby cause an excessive accumulation of collagens in disease processes associated with fibrosis. Although HSP47 promotes renal fibrosis, the underlying mechanism and associated signaling events have not been clearly delineated. We examined the role of HSP47 in renal fibrosis using a rat unilateral ureteral obstruction model and transforming growth factor (TGF)-β(1)-treated human proximal tubular epithelial (HK-2) cells. An upregulation of HSP47 in both in vivo and in vitro models was observed, which correlated with the increased synthesis of extracellular matrix (ECM) proteins and expression of tissue-type plasminogen activator inhibitor (PAI)-1. Blockade of HSP47 by short interfering RNA suppressed the expression of ECM proteins and PAI-1. In addition, TGF-β(1)-induced HSP47 expression in HK-2 cells was attenuated by ERK1/2 and JNK MAPK inhibitors. These data suggest that ERK1/2 and JNK signaling events are involved in modulating the expression of HSP47, the chaperoning effect of which on TGF-β(1) would ultimately contribute to renal fibrosis by enhancing the synthesis and deposition of ECM proteins.     

Survival of F-Specific RNA Coliphage, Feline Calicivirus, and Escherichia coli in Water: a Comparative Study

The relationship between the survival of enteric viral pathogens and their indicators (coliform bacteria and coliphages) is not well understood. We compared the survival rates of feline calicivirus (FCV), Escherichia coli, and a male-specific RNA coliphage MS2 at 4, 25, and 37°C for up to 28 days in dechlorinated water. The survival rates of E. coli and FCV, a surrogate of noroviruses (NV), had a high degree of correlation at 4 and 25°C, while MS2 phage survived significantly longer (P < 0.05) at these two temperatures. At 37°C, the survival rates for all three organisms were highly correlated. Decimal reduction values indicating the number of days needed for 90% reduction in titer (D values) decreased for all three organisms as storage temperatures increased. FCV had the shortest D value among all three organisms at all temperatures investigated. These findings indicate that F-specific RNA phages may be useful indicators of NV in the environment.