Nanoparticles sponges

Figure 7.5 Two topologically distinct types of mesoporous gold sponge, each with 50 volume % gold, (a) Swiss-cheese morphology produced by de-alloying, (b) aggregated particle morphology produced by sintering of nanoparticles.

Organisms use three conceptually different strategies to build their skeletal parts. The easiest approach to the filling of a given shape with solid material applies when there is no internal order or structure, that is, when the material is amorphous. A beautiful example is found within the Euplectella species of marine sponge, which comprises at least seven hierarchical levels within its silica skeleton, the lowest level consisting of silica nanoparticles.1 A second approach involves building skeletal materials... 

MCF-7 cells and their xenograph tumors, and compared with DOX-loaded pH-insensitive micelles made of PLLA-PEG with folate targeting groups (PHlM/f) [99]. The cellular localization of the nanoparticles was confirmed by confocal microscopy (Fig. 10.13). DOX delivered by PHSM/f was found uniformly distributed in the cytosol as well as in the nucleus, while DOX/PHlM/f was entrapped in endosome and multivesicular bodies. It was thus hypothesized that PHis, which is known to have an endosomal membrane-disruption activity induced by a proton sponge mechanism of its imidazole groups [209, 210], disrupted the compartment membrane and released DOX into the cytosol. As a result, DOX/PHSM/f showed much higher in vitro and in vivo anticancer activities toward DOX-resistant cells (Fig. 10.14). 

Sponges are animals that come under the phylum prolifera. Recently researchers have reported on the synthesis of nanoparticles using sources from marine animals including fish liver oil and sponges. Sponges play a role in transformation due to unspecialized cells. Sponges like Brevibacterium casei and Acanthella elongata were studied and reported on. 

Kiran et al. (2010) produced glycol hpid surfactant from marine-sponge-associated B. casei MSA 19 by solid state fermentation. The glycol lipid was used in the production of AgNPs which resulted in uniform and stable nanoparticles. 

Acanthella elongata, a marine sponge which belongs to primitive phylum, was utihzed for the preparation of gold nanoparticles and was studied by Inbakandan et al. (2010). The synthesized AuNPs were subjected to UV-visible spectroscopy, HR-TEM, FT-IR, and XRD. The results suggested a resonance peak at 526 nm with a spherical shape with an average size of 7—20 nm. 

Inbakandan, D., Venkatesan, S., Khan, S.A., 2010. Biosynthesis of gold nanoparticles utilizing marine spongs Acanthella elongata (Dendy, 1905). Colloid. Surf. B 81, 634—639. 

The main applications of collagen as dmg delivery systems are components in ophthalmology, sponges for burns or wounds, pellets and tablets for protein delivery, gel formulation in combination with liposomes for sustained dmg delivery, as controlling material for transdermal delivery, and nanoparticles for gene delivery. ... 

J. Barauskas, A. Misiunas, T. Gurmarsson, F. Tiberg, M. Johnsson, Sponge nanoparticle dispersions in aqueous mixtures of diglycerol monooleate, glycerol dioleate, and polysorbate 80. Langmuir 22, 6328-6334 (2006)... 

As chitosan is versatile, it can be manufactured into films, membranes, fibers, sponges, gels, beads, and nanoparticles, or supported on inert materials. The utilization of these materials presents many advantages in terms of applicability to a wide variety of process configurations. The various forms of chitin and chitosan are discussed below. 

Related to these structures and also of relevance for the preparation of nanoparticles are some amphiphile-based nanostructured phases which do not possess any long range order. For example, another type of bicontinuous phase with relation to the inverse bicontinous cubic phases is the so-called sponge phase (L3). Its curved bilayer structure is disordered so that the water channels adopt a sponge-like structure. Sometimes this phase is referred to as a "melted cubic (v2) phase". Moreover, also dispersions of inverse micellar phases (L2) have been described which may be regarded as "melted I2 phase". Although such disordered phases do not represent a liquid crystalline phase in a strict sense they are included here since they are of relevance for nanoparticulate drug delivery purposes. 

---