Development of nystatin-based antifungal, biodegradable polymer composite materials for food packaging via. melt processing approach

Novel bio-based, biodegradable packaging material was developed with multi-functional properties of good mechanical strength, potent biocompatibility, and antifungal attributes, predominantly against fungi vital in food spoilage. Biodegradable polymer composites were prepared with a natural antifungal agent, nystatin (Nyst), by melt processing technique for the first time. Initially, Polycaprolactone (PCL) was melt-mixed with various percentages of nystatin to produce nystatin-encapsulated PCL composites (PCL/Nyst). The as-prepared PCL/Nyst composites were melt-mixed with polylactic acid (PLA) to produce nystatin PLA/PCL blend composites. Subsequently, the prepared composites were compression molded in the form of films (1 mm) for further characterization. The composite's structural properties were evaluated by SEM, FTIR, mechanical and thermal studies. In addition, the composites were tested in vitro against a panel of pathogenic fungi and for antibiofilm attributes, specifically against three Candida species (C. albicans ATCC10231, C. parapsilosis ATCC22019, and C. glabrata ATCC2001), and foodborne Penicillium sp. All the composites containing 2 to 20 wt% nystatin displayed good activity and sustained nystatin release for up to 4 days. Thus, the overall study demonstrates the potential application of natural antifungal agents in biodegradable polymers to produce novel composite films for antimicrobial packaging without inducing any toxicity, judged from the toxicity assay using nematode Caenorhabditis elegans

[Review] Metal nanoparticles decorated two-dimensional nanosheets as heterogeneous catalysts for coupling reactions

International audienceThis review presents a brief discussion on the numerous synthetic techniques used to prepare metal nanoparticles supported on various two-dimensional (2D) materials. Special emphasis has been given to graphene and other 2D analogues such as g-C3N4, h-BN, MoS2, WS2 etc. supported metal nanoparticles. In addition to these, this review outlines the applications of the developed metal nanoparticles-2D composite materials for catalytic coupling reactions, which have recently emerged as a promising strategy in carbon-heteroatom or carbon-carbon bond formation. The effect of size and morphology of metal nanoparticles-2D composite materials on their catalytic performance toward different coupling reactions such as Suzuki, Heck, Sonogashira, etc. have been discussed in detail