Biopolymer nanoparticles

By varying the character and amount of substituents and the Mw of the starting dextran, the design of biopolymer nanoparticles of appropriate size is possible (Table 9). Thus, nanoparticles in the range 90-520 nm are available. 

Jones, O.G., Lesmes, U., Dubin, P., McClements, D.J. Effect of polysaccharide charge on formation and properties of biopolymer nanoparticles created by heat treatment of jS-lactoglobulin-pectin complexes. Food Hydrocolloids 24, 374—383 (2010)... 

PECs also have been the focus of an expanding number of studies for their wide use in medicine. For instance, biopolymer nanoparticles have been described as very promising nanosized carrier materials with great potential in health care and environmental sciences [140]. 

Jones GO, McClements DJ (2011) Recent progress in biopolymer nanoparticle and microparticle formation by heat-treating electrostatic protein-polysaccharide complexes. Adv Colloid Interfac 67 49-62... 

Fluorouracil is a chemotherapy used against some types of cancers [93]. Zhang et al., [93] developed 5-fluorouracil-loaded in biopolymer nanoparticles by reverse emulsion-SEDS, evaluated the pharmacokinetics by in vitro assays and obtained effective tumor inhibition in rats. Already Kalantarian et al., [94] used the SAS process to develop S-Fluoromacil nanoparticles for lung cancer treatment. 

A Facile One-Pot Synthesis of MSe (M = Cd orZn) Nanoparticles Using Biopolymer as Passivating Agent... 

Bozanic, D. K. Djokovic, V. Bibic, N. Sreekumari Nair, P. Georges, M. K. and Radhakrishnan, T. (2009). Biopolymer-protected CdSe nanoparticles. Carbohydrate Research, 344, 2383-2387. 

Oluwafemi, O. S and Adeyemi, O. O. (2010). One -pot room temperature synthesis of biopolymer -capped ZnSe nanoparticles. Journal of Materials Letters, 64, 2310-2313. 

Fig. 17 (a) Elastin-based stimulus-responsive gold nanoparticles. Reproduced from [131] by permission of The Royal Society of Chemistry (b) Functionalization of a glass surface with ELP. In the first step, the glass surface is aminosilylated with N-2-(aminoethyl)-3-aminopropyl-trimethoxysilane, then modified with glutaraldehyde. Subsequently, the stimulus-responsive biopolymer is covalently immobilized using reductive amination. Reproduced from [132] by permission of The Royal Society of Chemistry... 

The development of DNA sensors and high-density DNA arrays has been prompted by the tremendous demands for innovative analytical tools capable of delivering the genetic information in a faster, simpler, and cheaper manner at the sample source, compared to traditional nucleic acid assays. Nanoparticle-biopolymer conjugates offer great potential for DNA diagnostics and can have a profound impact upon bioanalytical chemistry. Nanoparticle/polynucleotide assemblies for advanced electrical detection of DNA sequences have been reviewed by Wang [145]. 

S8 Paknikar, KM., Nagpal, V., Pethkar, A.V. and Rajwade, J.M. (2005) Degradation of lindane from aqueous solutions using iron sulfide nanoparticles stabilized by biopolymers. Science and Technology of Advanced Materials, 6, 370-374. 

Charged polysaccharides can also serve as templates for the growth of metallic, semiconductor and magnetic nanoparticles. For instance, chitosan has been reported as a catalyst and stabilizing agent in the production of gold nanoparticles by the reduction oftetrachloroauric (III) acid by acetic acid. The biopolymer controls the size and the distribution of the synthesized Au nanoparticles and allows the preparation... 

Fig. 3.3 The common two-stage sol-gel process used to entrap biopolymers in a silica matrix (see Scheme 3.1). The first stage serves to hydrolyze alkoxide Equation (2) in the acidic or alkaline media. This is also attended with condensation reactions Equations (3) and (4) resulting in the formation of oligomeric silica that self-organizes in the form of sol nanoparticles. Biopolymers are entrapped in the...

Fig. 3.7 Schematic drawings demonstrating the main features of two-stage (A) and one-stage (B) procedures leading to a difference in the morphology of the fabricated materials. (A) Sol nanoparticles initially prepared in the first stage (1, see also Figure 3.3) can self-assemble into a three-dimensional network when they are in direct contact with each other. Forthis reason, a gel formed after cross-linking (sol-gel transition) has a smaller volume (2). (B) The initial stage (1) is represented by a solution of entangled biopolymer macromolecules. The...

The one-stage process with THEOS proceeds differently (Figure 3.7B). The difference is in the absence of sol nanoparticles in the initial solution. There are entangled macromolecular chains (stage 1, Figure 3.7B). The silica precursor is introduced in a biopolymer solution as a monomer. The experimental results available to date (see Section 3.4.2) demonstrate that instead of sol formation there... 

However, it has to be realized that biological templates remain inserted in the final nanoparticles and this is not acceptable for many applications. Nevertheless, some recent examples indicate that such biomimetic materials may be suitable for the design of biotechnological and medical devices [32]. For instance, it was shown that silica gels formed in the presence of p-R5 were excellent host matrices for enzyme encapsulation [33]. In parallel, biopolymer/silica hybrid macro-, micro- and nanocapsules were recently obtained via biomimetic routes and these exhibit promising properties for the design of drug delivery materials (see Section 3.1.1) [34,35],... 

Carrageenans and alginates present different conformations egg-box structure (alginates) and double helices (carrageenan) but both natural biopolymers are able to form gels and consequently, to control nanoparticle growth. 

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