Engineering living materials by synthetic biology.

Natural biological materials are programmed by genetic information and able to self-organize, respond to environmental stimulus, and couple with inorganic matter. Inspired by the natural system and to mimic their complex and delicate fabrication process and functions, the field of engineered living materials emerges at the interface of synthetic biology and materials science. Here, we review the recent efforts and discuss the challenges and future opportunities.

Preparation of composite aerogels based on sodium alginate, and its application in removal of Pb2+and Cu2+from water.

A novel Ethylenediamine-Modified Calcium Alginate Aerogel (ECAA) was synthesized by freeze-drying method, and used to remove Pb2+ and Cu2+ from aqueous solutions. The prepared adsorbent was characterized by using the FTIR spectra, SEM analysis and XPS analysis. The effects of the pH, initial metal ion concentration, adsorption kinetics, and isotherms had been studied systematically. Moreover, the ECAA can be regenerated by simple acid treatment and used repeatedly. It is interesting to note that almost no Ca2+ can be detected after the first cycle that confirmed the adsorption process involves ion exchange.The XPS spectra analyses further indicated that Pb2+ and Cu2+ were adsorbed via the chelation of -CO-NH, -NH2 and -OH. The results from these studies indicated the aerogel is a promising adsorbent to separate and recover the heavy metal ions from contaminated water.

Anticancer effect of extracts from a North American medicinal plant--wild sarsaparilla.

The wild sarsaparilla (Aralia nudicaulis) plant is richly distributed in North America, mainly in Canada. In the present study, 24 extracts were obtained from the rhizome, stem, leaf and fruit of wild sarsaparilla. In the presence of RH (hexane fraction from the rhizome), the survival rate of WiDr (human colon cancer cell) was 3.5 +/- 2.7% (IC50 = 30.1 +/- 3.5 microg/ml) and that of Molt (human leukemia cell) was 2.4 +/- 2.8% (IC50 = 7.0 +/- 0.6 microg/ml). The survival rate of HELA (human cervix cancer cell) was only 1.8 +/- 0.9% in the presence of FH (hexane fraction from the fruit of wild sarsaparilla) (IC50 = 33.3 +/- 2.7 microg/ml). The cytotoxicities of RH and FH against normal human umbilical vein endothelial cells were significantly lower than against the tested human cancer cells. RH appeared to be the best extract against WiDr and Molt, whereas FH was the most effective against HELA. Because of the rich natural supply, simple extraction procedure and high yield, RH and FH of wild sarsaparilla have the potential to be developed into selective anticancer nutraceutical and/or pharmaceutical products with few side-effects and low cost.

Xanthatin and xanthinosin from the burs of Xanthium strumarium L. as potential anticancer agents.

Xanthatin and xanthinosin, 2 sesquiterpene lactones isolated from the burs of Xanthiun strumarium L. (cocklebur), showed moderate to high in vitro cytotoxic activity in the human cancer cell lines WiDr ATCC (colon), MDA-MB-231 ATCC (breast), and NCI-417 (lung). Xanthatin and xanthinosin were purified as the result of a multi-screening bioassay-guided study of wild plant species of the family Asteraceae, collected from various sites in Saskatchewan, Canada. Seventy-five extracts at a single concentration of 100 microg/mL were evaluated for in vitro cytotoxicity to the human cancer cell lines used. The chloroform extract of Carduus nutans L. (nodding thistle) aerial parts (IC50, 9.3 microg/mL) and the hexane extract of Echinacea angustifolia DC. (narrow-leaved purple coneflower) root (IC50, 4.0 microg/mL) were moderately to highly cytotoxic to the lung cancer cell line. The chloroform extracts of X. strumarium L. burs and Tanacetum vulgare L. (tansy) aerial parts exhibited the highest cytotoxicity for all cell lines tested; their IC50 values, obtained from multidose testing, ranged from 0.1 to 6.2 microg/mL (X. strumarium) and from 2.4 to 9.1 microg/mL (T. vulgare). Further purification of the chloroform fraction of X. strumarium yielded xanthatin and xanthinosin in high yields. This is the first time that these compounds have been reported in the burs of X. strumarium. Their IC50 values are also reported herein.