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Start Over Language undetermined Journal macromolecular bioscience
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1. Silk Protein Paper with In Situ Synthesized Silver Nanoparticles

Author

Bin Tang, Yujia Liang, Benjamin J. Allardyce, Aarushi Sharma, Hannes C. Schniepp, Dinidu Perera, Sourabh Ghosh, and Rangam Rajkhowa

Subjects
Paper, In situ, Staphylococcus aureus, Silver, Materials science, Polymers and Plastics, Silk, Metal Nanoparticles, Nanoparticle, Fibroin, Bioengineering, Microbial Sensitivity Tests, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Silver nanoparticle, Nanomaterials, Biomaterials, Imaging, Three-Dimensional, Bombyx mori, Spectroscopy, Fourier Transform Infrared, Escherichia coli, Materials Chemistry, Animals, biology, Photoelectron Spectroscopy, Optical Imaging, Bombyx, 021001 nanoscience & nanotechnology, biology.organism_classification, Anti-Bacterial Agents, 0104 chemical sciences, SILK, Chemical engineering, Insect Proteins, Spectrophotometry, Ultraviolet, 0210 nano-technology, Antibacterial activity, Biotechnology
Abstract

Silver nanoparticles (AgNPs) are in situ synthesized for the first time on microfibrillated silk (MFS) exfoliated from domesticated Philosamia cynthia ricini (eri) and Bombyx mori (mulberry) silkworm silk fibers. The process is rapid (hours time), does not rely on harmful chemicals, and produces robust and flexible AgNPs coated MFS (MFS-AgNPs) protein papers with excellent handling properties. None of these can be achieved by approaches used in the past to fabricate AgNPs silk systems. MFS bonds the AgNPs strongly, providing good support and stabilization for the NPs, leading to strong wash fastness. The mechanical properties of the MFS-AgNPs papers largely do not change compared to the MFS papers without nanoparticles, except for some higher concentration of AgNPs in the case of mulberry silk. The improved tensile properties of eri silk papers with or without AgNPs compared to mulberry silk papers can be attributed to the higher degree of fibrillation achieved in eri silk and its inherent higher ductility. MFS-AgNPs from eri silk also exhibit strong antibacterial activity. This study provides the basis for the development of smart protein papers based on silk fiber and functional nanomaterials.

Published
2020

2. A New Method for the Evaluation of Biodegradable Plastic Using Coated Cellulose Paper

Author

Yutaka Tokiwa, Hyun-A. Lim, and Takao Raku

Subjects
Paper, Polymers and Plastics, Polyesters, Biomedical Engineering, Biocompatible Materials, Bioengineering, macromolecular substances, Biomaterials, chemistry.chemical_compound, Hydrolysis, Materials Chemistry, Organic chemistry, Cellulose, Trichoderma, Coated paper, Subtilisin, technology, industry, and agriculture, Lipase, Biodegradation, Polyester, Biodegradation, Environmental, Models, Chemical, chemistry, Chemical engineering, Evaluation Studies as Topic, Polycaprolactone, Microscopy, Electron, Scanning, Biodegradable plastic, Plastics, Biotechnology
Abstract

A highly sensitive analytical method for evaluation of poly(L-lactide) (PLA), poly(epsilon-caprolactone) (PCL), poly(beta-hydroxybutyrate) (PHB), and poly(butylene succinate) (PBS) degradability was developed using coated cellulose paper, prepared by penetration and adhesion of these plastics into/onto the cellulose paper. Enzymatic degradability of the obtained plastic coated papers was evaluated using various commercial proteases and lipases. PLA coated paper was highly susceptible to subtilisin and mammalian enzymes, alpha-chymotrypsin, elastase and trypsin. To our knowledge, this is the first report on the degradation of PLA coated paper using subtilisin and mammalian enzymes. Almost all lipase preparations degraded PCL and PHB coated papers but not PBS coated paper. The biodegradability of plastic coated paper was greater than that of plastic powder. The penetration of plastic into cellulose paper by coating improved the plastic degradability, and can be regulated easily.

Published
2004