Pullulan acetate

Na, K., Lee, E. S., and Bae, Y. H. (2003), Adriamycin loaded pullulan acetate/sulfonamide conjugate nanoparticles responding to tumor pH pH-dependent cell interaction, internalization and cytotoxicity in vitro, I. Controlled Release, 87(1-3), 3-13. 

Jung SW, Jeong Yl, Kim YH, Kim SH. Self-assembled polymeric nanoparticles of poly(ethylene glycol) grafted pullulan acetate as a novel drug carrier. Arch Pharmacal Res 2004 27(5) 562-569. Peppas NA. Devices based on intelligent biopolymers for oral protein delivery. Int J Pharm 2004 277(1-2) 11-17. 

Na, K. Lee, K.H. Bae, Y.H. pH-sensitivity and pH-dependent interior structural change of self-assembled hydrogel nanoparticles of pullulan acetate/oligo-sulfonamide conjugate. J. Control. Release 2004, 97, 513-525. 

Fig. 10.8 DOX release from PA/SDM nanoparticles at pH 8.0 ( ), 7.4 (o), 6.8 (T), and 6.4 (V). (The number of SDM groups per anhydroglucose unit of the pullulan acetate was 0.39.) (modified and reproduced from [146], with permission from Springer)...

Figure 10 Chemical structures of (a) pullulan acetate (PA) and (b) sulfadimethoxine (SDM). (Adapted from Ref. 92.)...

Zhao, L. Tang, J. (2010). Pullulan acetate coated magnetite nanojjarticles for hyper-thermia Preparation, characterization and in vitro experiments. Nano Res., 3, 23-31. 

The GBR resin works well for nonionic and certain ionic polymers such as various native and derivatized starches, including sodium carboxymethylcel-lulose, methylcellulose, dextrans, carrageenans, hydroxypropyl methylcellu-lose, cellulose sulfate, and pullulans. GBR columns can be used in virtually any solvent or mixture of solvents from hexane to 1 M NaOH as long as they are miscible. Using sulfonated PDVB gels, mixtures of methanol and 0.1 M Na acetate will run many polar ionic-type polymers such as poly-2-acrylamido-2-methyl-l-propanesulfonic acid, polystyrene sulfonic acids, and poly aniline/ polystyrene sulfonic acid. Sulfonated columns can also be used with water glacial acetic acid mixtures, typically 90/10 (v/v). Polyacrylic acids run well on sulfonated gels in 0.2 M NaAc, pH 7.75. 

Table 10-In Vitro Inhibition of Aureobasidium Pullulans By Ethyl Acrylate (EA) and Vinyl Acetate (VA) Copolymers...

Anaerobic organisms such as Dematium pullulans induce slimy fermentation which results in ropiness. These bacteria attack the sugar, but not glycerin nor alcohol and produce man-nite, carbon dioxide, lactic and acetic acids and alcohol. Their... 

Ethyl-2-(/J)-hydroxy-2-(T,2, 3. 4 -tetrahydro-T,T.4, 4 -tetramethyl-6 -naphthalenyl) acetate 53 (Figure 16.14) and the corresponding acid 54 were prepared as intermediates in the synthesis of the retinoic acid receptor gamma-specific agonist [86]. Enantioselective microbial reduction of ethyl 2-oxo-2-(T,2, 3. 4 -tetrahydro-T,T,4, 4 -tetramethyl-6-naphthalenyl) acetate 55 to alcohol 53 was carried out using Aureobasidiumpullulans SC 13849 at a 98% yield and with an EE of 96%. At the end of the reaction, hydroxyester 53 was adsorbed onto XAD-16 resin and, after filtration, recovered in 94% yield from the resin with acetonitrile extraction. The recovered (/ )-hydroxyester 53 was treated with Chirazyme L-2 or pig liver esterase to convert it to the corresponding (/ )-hydroxyacid 54 in quantitative yield. The enantioselective microbial reduction of ketoamide 55 to the corresponding (/ )-hydroxyamide 52 by A. pullulans SC 13849 has also been demonstrated [86]. 

There were also attempts to calibrate the SEC columns with help of broad molar mass dispersity poplymers but this is less lehable. The most common and well credible SEC cahbration standards are linear polystyrenes, PS, which are prepared by the anionic polymerizatioa As indicated in section 11.7, according to lUPAC, the molar mass values determined by means of SEC based on PS calibration standards are to be designated polystyrene equivalent molar masses . Other common SEC calibrants are poly(methyl methaciylate)s, which are important for eluents that do not dissolve polystyrenes, such as hexafluoroisopropanol, further poly(ethylene oxide)s, poly(vinyl acetate)s, polyolefins, dextrans, pullulans, some proteins and few others. The situation is much more complicated with complex polymers such as copolymers. For example, block copolymers often contain their parent homopolymers (see sections 11.8.3, 11.8.6 and 11.9). The latter are hardly detectable by SEC, which is often apphed for copolymer characterization by the suppliers (compare Figure 16). Therefore, it is hardly appropriate to consider them standards. Molecules of statistical copolymers of the same both molar mass and overall chemical composition may well differ in their blockiness and therefore their coils may assume distinct size in solution. In the case of complex polymers and complex polymer systems, the researchers often seek support in other characterization methods such as nuclear magnetic resonance, matrix assisted desorption ionization mass spectrometry and like. 

In addition, MMA-grafted pullulan (a water soluble polysaccharide, M, 100,000) was prepared by using ceric ammonium nitrate as initi-ater in an aqueous medium35. A scanning electron microphotograph of the film made from a butyl acetate-acetone solution showed an aggregated cell structure in the film like in Japanese lacquer films as shown in Fig. 18. 

Polymers with hydrolysable linkages in the backbone are very useful in a range of degradable materials. For disposable table-wares as cups or expendable packages many of them are still too expensive and do not exhibit the desirable combination of mechanical and chemical properties. Well-known synthetic hydrolysable polymers are polyesters [1], polycarbonates [2], polyanhydrides [2], polyamides [2] and poly(amino acids) [2]. Hydrolysable biopolymers may be cheaper than synthetically produced polymers (e.g. aliphatic polyesters such as polylactides) and many scientists today are looking for new possibilities using such traditional natural polymers as polysaccharides, proteins and lipids. Special interest is focused on poly(P-hydroxybutyrate) and its copolymers [3,4] (see Chapters 9 and 10). Well-known natural products such as Pullulan (a bacterial polysaccharide produced by Aerobasidium pullulans), cellulose acetate and starch, as well as synthetic polyvinyl alcohol are important degradable materials. 

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