Metal nanoparticles have unique optical, electronic, and catalytic properties. There exist well-defined physical and chemical processes for their preparation. Those processes often yield small quantities of nanoparticles having undesired morphology, and involve high temperatures for the reaction and the use of hazardous chemicals. Relatively, the older technique of bioremediation of metals uses either microorganisms or their components for the production of nanoparticles. The nanoparticles obtained from bacteria, fungi, algae, plants and their components, etc. appear environment-friendly, as toxic chemicals are not used in the processes. In addition to this, the formation of nanoparticles takes place at almost normal temperature and pressure. Control of the shape and size of the nanoparticles is possible by appropriate selection of the pH and temperature. Three important steps are the bioconversion of Ag+ ions, conversion of desired crystals to nanoparticles, and nanoparticle stability. Generally, nanoparticles are characterized by the UV-visible spectroscopy and use of the electron microscope. Silver nanoparticles are used as antimicrobial agents and they possess antifungal, anti-inflammatory, and anti-angiogenic properties. This review highlights the biosynthesis of silver nanoparticles by various organisms, possible mechanisms of their synthesis, their characterization, and applications of silver nanoparticles.

One of the zwitterion buffers that has shown significant therapeutic value in the treatment of pain due to cancer, immunologically mediated diseases, and the pain associated with these conditions is in the class of N-substituted amino-sulfonic acids known as "Good Buffers." Zwitterion molecules have neither a negative nor a positive charge; thus, they are neutral. 4-(2 Hydroxyethyl)-1-piperazine ethane sulfonic acid has been used for several decades in artificial biological systems (tissue culture) as a buffer. We have been exploring the therapeutic value of these zwitterionic buffers. Pilot animal studies have demonstrated that zwitterionic piperazine increases bone marrow hypercellularity and induces extramedullary hematopoiesis. We report the initial human use to explore dose toxic and physiologic effects of a fixed dose of the zwitterionic piperazine molecule. There appears to be potential therapeutic value in the treatment of pain due to cancer, and there are preliminary indications that tumor activity and tumor size are reduced. Immunologically mediated diseases may also be affected. Toxicity is low and there appear to be minimal side effects.

Urbanization and industrial development are increasing rapidly.

Development of a novel method for the quantification of lovastatin is an interesting problem in the analytical field. In the literature, many reports use spectrophotometric method for the quantification of lovastatin. However, the analysis of fermentation broth containing lovastatin appears to be inaccurate using spectrophotometric method. Hence, the estimation of lovastatin produced by Monascus purpureus and pure lovastatin was attempted by UV-visible spectrophotometer as well as HPLC. It was observed that the analogues and/or intermediates of lovastatin synthesized in the fermentation broth and the products of fermentation caused superimposition effect on the absorption spectrum. Phosphate is a medium constituent for the production of lovastatin by the organism which contributed significantly to the superimposition of absorption spectrum. On the other hand, HPLC analysis consistently gave reliable results for the estimation of lovastatin under all the experimental conditions studied.

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