Nanoparticles polysaccharide

Hence polysaccharides have been viewed as a potential renewable source of nanosized reinforcement. Being naturally found in a semicrystalline state, aqueous acids can be employed to hydrolyze the amorphous sections of the polymer. As a result the crystalline sections of these polysaccharides are released, resulting in individual monocrystalline nanoparticles [13]. The concept of reinforced polymer materials with polysaccharide nanofillers has known rapid advances leading to development of a new class of materials called Bionanocomposites, which successfully integrates the two concepts of biocomposites and nanometer sized materials. The first part of the chapter deals with the synthesis of polysaccharide nanoparticles and their performance as reinforcing agents in bionanocomposites. 

A similar procedure was adopted for synthesis of nanoparticles of cellulose (CelNPs). The polysaccharide nanoparticles were derivatised under ambient conditions to obtain nanosized hydrophobic derivatives. The challenge here is to maintain the nanosize even after derivatisation due to which less vigorous conditions are preferred. A schematic synthesis of acetyl and isocyanate modified derivatives of starch nanoparticles (SNPs) is shown in scheme 3. The organic modification was confirmed from X-ray diffraction (XRD) pattern which revealed that A- style crystallinity of starch nanoparticles (SNPs) was destroyed and new peaks emerged on derivatisation. FT-IR spectra of acetylated derivatives however showed the presence of peak at 3400 cm- due to -OH stretching indicating that the substitution is not complete. 

Scheme 2. Various conditions and steps involving general synthesis of polysaccharide nanoparticles...

The results of the mechanical properties can be explained on the basis of morphology. The scanning electron micrographs (SEM) of fractured samples of biocomposites at 40 phr loading are shown in figure. 3. It can be seen that all the bionanofillers are well dispersed into polymer matrix without much agglomeration. This is due to the better compatibility between the modified polysaccharides nanoparticles and the NR matrix (Fig. 4A and B). While in case of unmodified polysaccharides nanoparticles the reduction in size compensates for the hydrophilic nature (Fig. 3C and D). In case of CB composites (Fig. 3E) relatively coarse, two-phase morphology is seen. 

Kida T, Inoue K, Akagi T et al (2007) Preparation of novel polysaccharide nanoparticles by the self-assembly of amphiphilic pectins and their protein-encapsulation ability. Chem Lett 36 940-941... 

Sarmento, B., A. Ribeiro, et al. (2007a). Oral bioavailability of insulin contained in polysaccharide nanoparticles. Biomacromolecules 8(10) 3054-60. 

Vauthier, C. Couvreur, P. Development of polysaccharide nanoparticles as novel drug carrier systems. In Handbook of Pharmaceutical Controlled Release Technology Wise, Trantolo, Cichon, Inyang, Stottmeister, Eds. Marcel Dekker, Inc. New York, 2000 413 29, Chap. 21. 

Vauthier C, Couvreur P (2000). Development of Polysaccharide Nanoparticles as Novel Drug Carrier Systems. In D L Wise (ed.). Handbook of Pharmaceutical Controlled Release Technology. Marcel Dekker, New York, pp. 413-429. 

Bertholon I, Vauthier C, Labarre D (2006). Core-shell poly(isobutylcyanoacrylate)-polysaccharide nanoparticles Influences of surface morphology, length and type of polysaccharide on complement activation in vitro. Pharm. Res. 23 1313-1323. 

Rocha S, Generalov R, Pereira MDC, Peres I, Juzenas P, Coelho MAN. Epigallocatechin gallate-loaded polysaccharide nanoparticles for prostate cancer chemoprevention. Nanomedicine. 2011 6(l) 79-87. 

Figure 21.13. A) High power microscope image showing that polysaccharide nanoparticles selectively associate with primary human bone marrow stromal cells in a 3D cell suspensions (n=12). The alginate nanocapsule core is stained with a fluorescent dye (Cell Tracker Red) which in white transmitted light is blue. B) TEM image showing presence of nanocapsules (i) at the surface of a primary hBMSC cell membrane and (ii) internalized within vacuoles. The yellow arrows denote position of nanocapsules.

Keywords Microbial Polysaccharides Nanoparticles Drug delivery... 

A. Jain, S.K. Jain, N. Ganesh, J. Barve, and A.M. Beg, Design and development of ligand-appended polysaccharidic nanoparticles for the delivery of oxaliplatin in colorectal cancer. Nanomedicine Nanotechnology, Biology and Medicine, 6 (1), 179-190, 2010. 

Water evaporation performed above the glass transition temperature of the polymer. During water evaporation, the solid content in the medium increases and the latex particles get closer, adopting a polyhedral form. In this way, a continuous polymeric film is created, containing the dispersed polysaccharide nanoparticles. 

When using nonaqueous systems, the processes of nonpolar polymer nanocomposites reinforced with polysaccharide nanoparticles involve dispersion in the organic medium of nanoparticles, coating with a surfactant, or surface chemical modification of the nanoparticles to reduce their surface energy and to increase dispersibility in nonpolar media. The decrease of surface energy ensures dispersion of nanoparticles in organic liquids with low polarity. 

Sarmento, B., Ribeiro, A. n., Veiga, E, Ferreira, D. and Neufeld, R. (2007) Oral bioavailability of insuhn contained in polysaccharide nanoparticles . Biomacromolecules, 8,3054-3060. 

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