Arsénio Vasconcelos Sá

Gallium labeled NOTA-based conjugates for peptide receptor-mediated medical imaging.

We report a straightforward and efficient synthetic strategy for the synthesis of three model glycine-arginine-glycine-aspartic acid-glycine (GRGDG) conjugates based on derivatives of NOTA and of their Ga(III) complexes targeted to the integrin α(ν)β(3) receptor. (71)Ga NMR spectroscopy showed that the Ga(III)-labeled conjugates are highly stable in aqueous solution. The (67)Ga-labeled conjugates proved to have high kinetic stability and showed a weak but specific binding to the receptors in a U87MG-glioblastoma cell line.

Biodegradable polymernanocomposites for packaging applications

Abstract Biodegradable polymers have attracted a high interest in a wide range of applications, including packaging, due to the increasing social concerns. To meet the growing demand for sustainability and environmental safety, a number of studies using biodegradable polymers focused on the development of packaging products, is increasing in order to produce materials that could rapidly degrade and completely mineralize. Biodegradable polymers can be obtained from renewable resources (starch, chitin, cellulose, casein, zein, and soy protein), synthesized using fossil derivatives [poly(lactic acid) and poly(ɛ-caprolactone)] or produced by bacteria (polyhydroxyalkanoates). Unfortunately, the use of biopolymers as packaging materials has drawbacks, such as, poor mechanical, thermal, and barrier properties when compared to conventional nonbiodegradable materials. Due to this, many research efforts were made to improve properties of biopolymers, including the preparation of nanocomposite materials. This chapter presents examples of biodegradable polymers from different sources and the development of new materials, nanocomposites, for food-packaging applications.

Bioplastics from agro-wastes for food packaging applications

Abstract Bioplastics exhibit unique properties and can be produced from plants and crop wastes, among others, cellulose, proteins, and starch are some of the examples. Due to environmental concerns, it is of high priority to replace conventional plastics with bioplastics, and even better if they are directly synthesized from agro-wastes. Green chemistry methodology is applied to extract natural polymers, such as cellulose, from vegetable wastes. This chapter focuses on the preparation of new functional biopolymers for packaging based on extracted cellulose, which exhibits broadly tunable thermomechanical properties and biodegradation. Therefore, this contribution shows the potential of agro-wastes to produce new cellulose-based bioplastics for food packaging applications.