Novel crosslinking methods to design hydrogels

Distribution and importance of microplastics in the marine environment: A review of the sources, fate, effects, and potential solutions

Properties of lactic acid based polymers and their correlation with composition

Department of Chemistry, Department of Radiology, Washington University in Saint Louis, Saint Louis, Missouri 63130, Department of Chemistry, Texas A&M University, College Station, Texas 77842, Cancer Center Karolinska, Department of Oncology-Pathology CCK, R8:03 Karolinska Hospital and Institute, SE-171 76 Stockholm, Sweden, and Department of Chemistry and Biochemistry, Department of Materials, and Materials Research Laboratory, University of California, Santa Barbara, California 93106

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Applications of Orthogonal “Click” Chemistries in the Synthesis of Functional Soft Materials

Poly(lactic-co-glycolic) acid (PLGA) has attracted considerable interest as a base material for biomedical applications due to its: (i) biocompatibility; (ii) tailored biodegradation rate (depending on the molecular weight and copolymer ratio); (iii) approval for clinical use in humans by the U.S. Food and Drug Administration (FDA); (iv) potential to modify surface properties to provide better interaction with biological materials; and (v) suitability for export to countries and cultures where implantation of animal-derived products is unpopular. This paper critically reviews the scientific challenge of manufacturing PLGA-based materials with suitable properties and shapes for specific biomedical applications, with special emphasis on bone tissue engineering. The analysis of the state of the art in the field reveals the presence of current innovative techniques for scaffolds and material manufacturing that are currently opening the way to prepare biomimetic PLGA substrates able to modulate cell interaction for improved substitution, restoration, or enhancement of bone tissue function.

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An Overview of Poly(lactic-co-glycolic) Acid (PLGA)-Based Biomaterials for Bone Tissue Engineering

Poly(ethylene terephthalate) (PET) is used extensively worldwide in plastic products, and its accumulation in the environment has become a global concern. Because the ability to enzymatically degrade PET has been thought to be limited to a few fungal species, biodegradation is not yet a viable remediation or recycling strategy. By screening natural microbial communities exposed to PET in the environment, we isolated a novel bacterium, Ideonella sakaiensis 201-F6, that is able to use PET as its major energy and carbon source. When grown on PET, this strain produces two enzymes capable of hydrolyzing PET and the reaction intermediate, mono(2-hydroxyethyl) terephthalic acid. Both enzymes are required to enzymatically convert PET efficiently into its two environmentally benign monomers, terephthalic acid and ethylene glycol.

http://science.sciencemag.org/content/sci/351/6278/1196.full.pdf

A Bacterium That Degrades and Assimilates Poly(ethylene Terephthalate)

Most petroleum-derived plastics, as exemplified by poly(ethylene terephthalate) (PET), are chemically inactive and highly resistant to microbial attack. The accumulation of plastic waste results in environmental pollution and threatens ecosystems, referred to as the “microplastic issue”. Recently, PET hydrolytic enzymes (PHEs) have been identified and we reported PET degradation by a microbial consortium and its bacterial resident, Ideonella sakaiensis. Bioremediation may thus provide an alternative solution to recycling plastic waste. The mechanism of PET degradation into benign monomers by PET hydrolase and mono(2-hydroxyethyl) terephthalic acid (MHET) hydrolase from I. sakaiensis has been elucidated; nevertheless, biodegradation may require additional development for commercialization owing to the low catalytic activity of these enzymes. Here, we introduce PET degrading microorganisms and the enzymes involved, along with the evolution of PHEs to address the issues that hamper microbial and enzymatic PE...

Biodegradation of PET: Current Status and Application Aspects

Melt/solid polycondensation of l-lactic acid: an alternative route to poly(l-lactic acid) with high molecular weight

The melt/solid polycondensation of L-lactic acid (LA) was successfully conducted using a binary catalyst system comprising tin dichloride hydrate and p-toluenesulfonic acid (TSA). First, a thermal oligocondensate of LA with a degree of polymerization of eight was mixed with the binary catalyst and subjected to melt polycondensation at 180°C for 5 h to obtain a melt polycondensate with an average molecular weight of 13 000 Da. This melt polycondensate was then heat treated at 105°C for 2 h and subjected to solid-state polycondensation under various conditions to obtain a high-molecular-weight polymer of poly(L-lactic acid) (PLLA).In a typical case, the solid-state reaction was performed by raising the temperature from 130 to 155°C, or at a constant temperature of 140 or 150°C. In the former case the molecular weight of PLLA increased linearly with the temperature increase, while in the latter case the molecular weight increased above 500 000 Da in a relatively short reaction time. The crystallization of th...

Ikuo Taniguchi

Papers

A Bacterium That Degrades and Assimilates Poly(ethylene Terephthalate)

Biodegradation of PET: Current Status and Application Aspects

Melt/solid polycondensation of l-lactic acid: an alternative route to poly(l-lactic acid) with high molecular weight

Synthesis and Properties of High-Molecular-Weight Poly(L-Lactic Acid) by Melt/Solid Polycondensation under Different Reaction Conditions:

Microbial production of poly(hydroxyalkanoate)s from waste edible oils