Prediction studies of environment-friendly biodegradable polymeric packaging based on PLA. Influence of specimens' thickness on the hydrolytic degradation profile.

Application of new biodegradable polymer packaging based on polylactide (PLA), susceptible to organic recycling, can help in the waste reduction in landfills. In this paper, the results of the study on abiotic degradation of PLA and its blend containing 15 mol% of poly[(R,S)-3-hydroxybutyrate], as a model for the first step of organic recycling were presented. The samples used for this study have different shapes and thicknesses: rigid films and cuboid-bars. Particular emphasis was placed on determining the pattern of degradation products released into the medium. Originally, the results of present study revealed that the application of electrospray ionization mass spectrometry supported by high performance liquid chromatography allowed envisaging the differences in the degradation products pattern released from the studied PLA-based samples differing in thickness. The significant differences in degradation products pattern were predominately observed in the first steps of incubation process and are caused by an autocatalytic effect, which occurs mainly during degradation of the large size PLA samples. Although, the thickness of PLA-based packaging changes the degradation product patterns, however this does not increase the total amounts of acids released to the medium. Thus, it may be concluded that thickness should not affect significantly organic recycling of the packaging.

Development of amphoteric alginate/aminated chitosan coated microbeads for oral protein delivery.

A new amphoteric biopolymer carrier based on alginate and aminated chitosan coated microbeads (Alg/AmCS) was developed and characterized for bovine serum albumin (BSA) protein delivery. The amphoteric character was investigated through studying the swelling and in vitro BSA release behaviors of the developed microbeads in simulated gastric (SGF; pH1.2), intestinal (SIF; pH6.8), and colonic (SCF; pH7.4) fluids. The pH sensitivity was found to depend on the amount of AmCS in the coating medium. The results were interpreted from the view of the individual pH sensitivity of alginate and aminated chitosan in addition to the ionic interaction between them under the studied pHs. Besides; it was found that the BSA loading efficiency (LE) exceeded 82% regardless of the initial concentration of BSA. The released amount of BSA reached approximately 63% and 86% in SIF and SCF, respectively, using 0.25% AmCS. The stability of alginate microbeads in SCF was improved with increasing AmCS concentration in the coating medium up to 2%. Furthermore, the developed microbeads demonstrated their ability for biodegradation in addition to their antibacterial activities against selected bacterial strains. The results clearly suggested that Alg/AmCS coated microbeads could be suitable carriers for site-specific protein delivery in the intestinal and colon tracts.