Immobilization of Lipase From Candida rugosa on Layered Double Hydroxides for Esterification Reaction

Topology dependent modification of layered double hydroxide for therapeutic and diagnostic platform

Layered double hydroxide is a family of two-dimensional materials with wide range of compositions. Recently, its ability to accommodate various chemical species and biocompatibility have been attracted in the biomedical applications to develop drug delivery system and nanodiagnostics. In this review, we categorized biomedical approaches of layered double hydroxide with respect to the three topologies of, namely, interlayer space, outer surface with particle edge, and the lattice points. There have been extensive researches on the intercalation of drug or tracing to make use of interlayer space of layered double hydroxide for drug stabilization, sustained release, cellular delivery and etc. Outer surface or edge has been utilized to immobilization of large therapeutic moieties and to attach tracing moiety. Lattice points consisting of various metal species could be utilized for the specific metal species like paramagnetic elements or radioisotopes. Based on these topologies in layered double hydroxide, both the synthetic routes and the achieved functionalities in terms of biomedical application will be discussed.

Clay-Na as a sorbent for the extraction of anti-inflammatory compounds in water samples

In this work, clay-Na particles are used as the adsorbent for the solid-phase extraction of acidic compounds. The novel sorbent under study is based on high-specific surface area, cation-exchange capacity designed specifically to offer ion-exchange properties with the goal being to selectively extract a group of acidic compounds. The effects of the extraction parameters including extraction elution solvent, sample volume and pH. In optimum conditions, the repeatability for one fiber (n = 3), expressed as % relative standard deviation, was between 0.3 and 4.3% for the acid compounds. The detection limits for the studied acidic compounds were between 0.1-0.6 μg/L. The developed method offers the advantages of being simple to use and having a low cost of equipment.

Inorganic nanovectors for nucleic acid delivery

Nucleic acids show immense potential to treat cancer, acquired immune deficiency syndrome, neurological diseases and other incurable human diseases. Upon systemic administration, they encounter a series of barriers and hence barely reach the site of action, the cell. Intracellular delivery of nucleic acids is facilitated by nanovectors, both viral and non-viral. A major advantage of non-viral vectors over viral vectors is safety. Nanovectors evaluated specifically for nucleic acid delivery include polyplexes, lipoplexes and other cationic carrier-based vectors. However, more recently there is an increased interest in inorganic nanovectors for nucleic acid delivery. Nevertheless, there is no comprehensive review on the subject. The present review would cover in detail specific properties and types of inorganic nanovectors, their preparation techniques and various biomedical applications as therapeutics, diagnostics and theranostics. Future prospects are also suggested.

Separation of patatins and protease inhibitors from potato fruit juice with clay minerals as cation exchangers

Potato fruit juice as a by-product of the starch industry contains proteins with interesting functionalities such as protease inhibitors or patatin with its high nutritional value. Due to their functional properties, these proteins are principally of industrial interest. A drawback for the application of these potato proteins is the separation and isolation under maintenance of the biological activity. So far, there are no methods in literature, which are satisfying concerning the costs or the separation performance. In this study, we show a chromatographic approach using natural clay minerals as cation exchangers to separate two protein fractions in potato fruit juice. Additionally, the content of glycoalkaloids naturally occurring in potatoes is significantly reduced in a single step together with the separation of the patatins and the protease inhibitors.

WITHDRAWN: Inorganic nanoparticles for cancer imaging and therapy

The Publisher regrets that this article is an accidental duplication of an article that has already been published, doi:10.1016/j.jconrel.2011.07.005. The duplicate article has therefore been withdrawn.

Inorganic nanoparticles for cancer imaging and therapy

Inorganic nanoparticles have received increased attention in the recent past as potential diagnostic and therapeutic systems in the field of oncology. Inorganic nanoparticles have demonstrated successes in imaging and treatment of tumors both ex vivo and in vivo, with some promise towards clinical trials. This review primarily discusses progress in applications of inorganic nanoparticles for cancer imaging and treatment, with an emphasis on in vivo studies. Advances in the use of semiconductor fluorescent quantum dots, carbon nanotubes, gold nanoparticles (spheres, shells, rods, cages), iron oxide magnetic nanoparticles and ceramic nanoparticles in tumor targeting, imaging, photothermal therapy and drug delivery applications are discussed. Limitations and toxicity issues associated with inorganic nanoparticles in living organisms are also discussed.

Immobilization of the aminopeptidase from Aeromonas proteolytica on Mg2+/Al3+ layered double hydroxide particles

A novel biomaterial formed by the immobilization of the Aminopeptidase from Aeromonas proteolytica (AAP) on synthetic Mg2+ and Al3+ ion-containing layered double hydroxide (LDH) particles was prepared. Immobilization of AAP on the LDH particles in a buffered, aqueous mixture is rapid such that the maximum loading capacity, 1×10(-9) moles of AAP/mg LDH, is achieved in a few minutes. X-ray powder diffraction of LDH samples before and after treatment with AAP indicates that the enzyme does not intercalate between the layers of LDH, but instead binds to the surface. Treatment of AAP/LDH with various amounts of salt in a buffered mixture demonstrates that between 15 and 20% of AAP can be removed from the LDH by washing the composite material in 0.2 M NaCl. However, the residual AAP remains bound to the LDH even at 1 M salt concentrations. A suspension of the AAP/LDH biomaterial in 10 mM Tricine buffered, aqueous solution (pH 8.0 and 25° C) catalyzes the hydrolysis of l-leucine-p-nitroanilide demonstrating that immobilized AAP remains available to substrate and retains its catalytic activity. Recycling experiments reveal that the AAP/LDH particles can be recovered and reused multiple times without appreciable loss of activity. This work provides the foundation for the development of materials that will function in the degradation or detection of peptide hormones or neurotoxins.

Layered double hydroxide nanoparticles in gene and drug delivery

Layered double hydroxides (LDHs) have been known for many decades as catalyst and ceramic precursors, traps for anionic pollutants, catalysts and additives for polymers, but their successful synthesis on the nanometer scale a few years ago opened up a whole new field for their application in nanomedicine. The delivery of drugs and other therapeutic/bioactive molecules (e.g., peptides, proteins, nucleic acids) to mammalian cells is an area of research that is of tremendous importance to medicine and provides manifold applications for any new developments in the area of nanotechnology. Among the many different nanoparticles that have been shown to facilitate gene and/or drug delivery, LDH nanoparticles have attracted particular attention owing to their many desirable properties. This review aims to report recent progress in gene and drug delivery using LDH nanoparticles. It summarizes the advantages and disadvantages of using LDH nanoparticles as carriers for nucleic acids and drugs against the general background of bottlenecks that are encountered by cellular delivery systems. It describes further the models that have been proposed for the internalization of LDH nanoparticles into cells so far and discusses the intracellular fate of the particles and their cargo. The authors offer some remarks on how this field of research will progress in the near future and which challenges need to be overcome before LDH nanoparticles can be used in a clinical setting.

Preparation of layered double hydroxides and their applications as additives in polymers, as precursors to magnetic materials and in biology and medicine

In recent years layered double hydroxides (LDHs), also known as hydrotalcite-like materials, have attracted considerable interest from both industry and academia. In this article, we discuss methods of preparing LDHs with an emphasis on the way in which particle size and morphology can be controlled with regard to specific target applications; scale-up of one such preparation procedure is also described. In addition, we review selected applications of LDHs developed by our own and other laboratories.

Current awareness on yeast

In order to keep subscribers up‐to‐date with the latest developments in their field, this current awareness service is provided by John Wiley & Sons and contains newly‐published material on yeasts. Each bibliography is divided into 10 sections. 1 Books, Reviews & Symposia; 2 General; 3 Biochemistry; 4 Biotechnology; 5 Cell Biology; 6 Gene Expression; 7 Genetics; 8 Physiology; 9 Medical Mycology; 10 Recombinant DNA Technology. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. (4 weeks journals ‐ search completed 10th. Nov. 2004)