Advanced Biopolymer-Based Nanocomposites and Hybrid Materials

The exploitation of naturally occurring polymers to engineer advanced nanocomposites and hybrid materials is the focus of increasing scientific activity, explained by growing environmental concerns and interest in the peculiar features and multiple functionalities of these macromolecules. Natural polymers, such as polysaccharides and proteins, present a remarkable potential for the design of all kinds of materials for application in a multitude of domains. This Special Issue collected the work of scientists on the current developments in the field of multifunctional biopolymer-based nanocomposites and hybrid materials with a particular emphasis on their production methodologies, properties, and prominent applications. Thus, materials related to bio-based nanocomposites and hybrid materials manufactured with different partners, namely natural polymers, bioactive compounds, and inorganic nanoparticles, are reported in the Special Issue Advanced Biopolymer-Based Nanocomposites and Hybrid Materials

Chemoprevention of 1,2-dimethylhydrazine-induced colonic preneoplastic lesions in Fischer rats by 6-methylsulfinylhexyl isothiocyanate, a wasabi derivative

The preventive effects of dietary exposure to a wasabi derivative 6-methylsulfinylhexyl isothiocyanate (6-MSITC) during the initiation and post-initiation phases on the development of 1,2-dimethylhydrazine (DMH)-induced colonic aberrant crypt foci (ACF), and β-catenin-accumulated crypts (BCAC) were investigated in male F344 rats. To induce ACF and BCAC, rats were given four weekly subcutaneous injections of DMH (40 mg/kg body weight). The rats also received diets containing 200 or 400 ppm 6-MSITC during the initiation or post-initiation phases. The experiment was terminated 12 weeks after the start. DMH exposure produced a substantial number of ACF (323.8±69.7/colon) and BCAC (3.80±1.05/cm(2)) at the end of the study. Dietary administration of 6-MSITC at a dose of 400 ppm during the initiation phase caused a significant reduction in the total number of ACF (52% reduction, P<0.0001), larger ACF (4 or more crypt ACF) (58% reduction, P<0.001) and BCAC (76% reduction, P<0.00001). The dietary exposure to 6-MSITC significantly reduced the size (crypt multiplicity) of BCAC during both initiation and post-initiation treatment when compared to group 1 treated with DMH alone. Immunohistochemically, 6-MSITC administration lowered the proliferating cell nuclear antigen labeling index in ACF and BCAC. In addition, protein levels of hepatic cytochrome P-450 isozymes at 24 h after 6-MSITC exposure were significantly suppressed (P<0.01). The results indicated that 6-MSITC exerted chemopreventive effects in the present short-term colon carcinogenesis bioassay, through alterations in cell proliferation activity and drug metabolizing enzyme levels

Synthesis of Amphiphilic Blockcopolymer Using Mechanically Produced Macromonomers Possessing Anhydrate as a Terminal Group and Its Application to Polymeric Micelles

We have synthesized macromonomers by mechanochemical reaction of poly(benzyl methacrylate) (PBzMA) and maleic anhydride (MA). The ESR spectrum of the fractured sample of PBzMA and MA showed a broad singlet, which was apparently different from the spectrum of PBzMA mechanoradical. The amphiphilic blockcopolymer was synthesized with macromonomer of PBzMA and amino-terminated polyethyleneglycol (a-methyl-w-aminopropoxy polyoxyethylene, MEPA). The number average molecular weight of the produced amphiphilic blockcopolymer was 33,000. Polymeric micelles were readily prepared from the present amphiphilic blockcopolymer by a dialysis method. The mean diameter of the micelles measured by dynamic light scattering was about 146 nm. It was shown that the present macromonomer mechanically produced can be used for the synthesis of amphiphilic bockcopolymer to form polymeric micelles

Synthesis of Amphiphilic Blockcopolymer Using Mechanically Produced Macromonomers Possessing Anhydrate as a Terminal Group and Its Application to Polymeric Micelles

We have synthesized macromonomers by mechanochemical reaction of poly(benzyl methacrylate) (PBzMA) and maleic anhydride (MA). The ESR spectrum of the fractured sample of PBzMA and MA showed a broad singlet, which was apparently different from the spectrum of PBzMA mechanoradical. The amphiphilic blockcopolymer was synthesized with macromonomer of PBzMA and amino-terminated polyethyleneglycol (a-methyl-w-aminopropoxy polyoxyethylene, MEPA). The number average molecular weight of the produced amphiphilic blockcopolymer was 33,000. Polymeric micelles were readily prepared from the present amphiphilic blockcopolymer by a dialysis method. The mean diameter of the micelles measured by dynamic light scattering was about 146 nm. It was shown that the present macromonomer mechanically produced can be used for the synthesis of amphiphilic bockcopolymer to form polymeric micelles

Drug Release Profile and Cellular Uptake of Polymeric Prodrugs Synthesized from Amphiphilic Blockcopolymer Using Mechanically Produced Macromonomers Possessing Anhydrate as a Terminal Group

In this paper, the polymeric micelle was fabricated with amphiphilic block copolymer which was synthesized by the condensation of mechanochemically produced PBzMA macromonomer with a-methyl-w-aminopropoxy polyoxyethylene. Although the polymeric micelles containing 5-fluorouracil (5-FU) or rohdamine showed the narrow size distribution as well as blank polymeric micelles, the particle diameter of the polymeric micelles containing 5-FU or rohdamine was larger than that of blank polymeric micelle. Polymeric micelle containing 5-FU slowly released 5-FU and about 10 % of 5-FU was released within 72 h. The present polymeric micelle was uptaken by A549 cells, but HepG2 cells did not. Cytotoxicity of Polymeric micelle containing 5-FU was not observed against HepG2 and A549 cells in this experimental condition. It was considered that the slow release of 5-FU from Polymeric micelle might cause the insufficient cytotoxicity

Drug Release Profile and Cellular Uptake of Polymeric Prodrugs Synthesized from Amphiphilic Blockcopolymer Using Mechanically Produced Macromonomers Possessing Anhydrate as a Terminal Group

In this paper, the polymeric micelle was fabricated with amphiphilic block copolymer which was synthesized by the condensation of mechanochemically produced PBzMA macromonomer with a-methyl-w-aminopropoxy polyoxyethylene. Although the polymeric micelles containing 5-fluorouracil (5-FU) or rohdamine showed the narrow size distribution as well as blank polymeric micelles, the particle diameter of the polymeric micelles containing 5-FU or rohdamine was larger than that of blank polymeric micelle. Polymeric micelle containing 5-FU slowly released 5-FU and about 10 % of 5-FU was released within 72 h. The present polymeric micelle was uptaken by A549 cells, but HepG2 cells did not. Cytotoxicity of Polymeric micelle containing 5-FU was not observed against HepG2 and A549 cells in this experimental condition. It was considered that the slow release of 5-FU from Polymeric micelle might cause the insufficient cytotoxicity