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PLA Film (pla + film)

Distribution by Scientific Domains

Polymers and Materials Science	60%

Selected Abstracts

Antimicrobial activity of nisin incorporated in pectin and polylactic acid composite films against Listeria monocytogenes

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 2 2009
Tony Jin
Summary An extruded composite food packaging film containing pectin, polylactic acids (PLAs) and nisin was developed to inhibit Listeria monocytogenes. The mechanical properties and surface structure of the film were also examined. Cells of L. monocytogenes were reduced by 2.1, 4.5 and 3.7 log units mL,1 by the pectin plus PLA (pectin/PLA) film containing nisin (1000 IU mL,1 of tested liquid) in Brain Heart Infusion (BHI) broth, liquid egg white and orange juice, respectively, after 48 h at 24 °C. Pectin played an important roll in embedding nisin into the film. The pectin/PLA film had a similar stiffness but lower tensile strength, elongation and fracture energy than the pure PLA film. These data suggested that nisin incorporated into the pectin/PLA film was an effective approach to reducing L. monocytogenes in a typical growth medium (e.g. BHI broth) as well as in foods (e.g. orange juice and liquid egg). [source]

Controlled release of argatroban from PLA film,Effect of hydroxylesters as additives on enhancement of drug release

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008
Akira Mochizuki
Abstract The aim of this study was to develop a drug eluting stent that prevents vein restenosis. For this, we selected argatroban as the study drug and poly(lactic acid) (PLA) as the matrix. To enhance the release of argatroban from PLA film, the addition of hydroxylesters (additives) was investigated. The additives investigated were diethyl tartrate (DET), diethyl malate (DEM), and triethyl citrate (TEC). Marked enhancement of drug release was observed in DET-added film, while TEC- or DEM-added film showed little enhancement. To clarify the effect of DET, the release profile based on the contents of the drug and DET in the film and the effect of alkyl chain length of tartrate were studied. Tartrates used were dimethyl, di- i -propyl, and di- n -butyl esters (DMT, DiPT, and DnBT, respectively), and the enhancement order was DMT , DET , DiPT , DBT , PLA alone. The reasons for enhancement were discussed from the viewpoint of drug release behavior, degradation of PLA, water uptake within the film, and SEM observations. It was concluded that enhancement of drug release was due to large amounts of water uptake within the film which resulted in the formation of open pores at its surface. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

Synthesis and characterization of amphiphilic block copolymers with allyl side-groups

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 23 2007
Xiuli Hu
Abstract The synthesis of a new cyclic carbonate monomer containing an allyl group was reported and its biodegradable amphiphilic block copolymer, poly(ethylene glycol)- block -poly(L -lactide- co -5-methyl-5-allyloxycarbonyl-propylene carbonate) [PEG- b -P(LA- co -MAC)] was synthesized by ring-opening polymerization (ROP) of L -lactide (LA) and 5-methyl-5-allyloxycarbonyl-1,3-dioxan-2-one (MAC) in the presence of poly (ethylene glycol) as a macroinitiator, with diethyl zinc as a catalyst. 13C NMR and 1H NMR were used for microstructure identification of the copolymers. The copolymer could form micelles in aqueous solution. The core of the micelles is built of the hydrophobic P(LA- co -MAC) chains, whereas the shell is set up by the hydrophilic PEG blocks. The micelles exhibited a homogeneous spherical morphology and unimodal size distribution. By using the cyclic carbonate monomer containing allyl side-groups, crosslinking of the PEG- b -P(LA- co -MAC) inner core was possible. The adhesion and spreading of ECV-304 cells on the copolymer were better than that on PLA films. Therefore, this biodegradable amphiphilic block copolymer is expected to be used as a biomaterial for drug delivery and tissue engineering. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5518,5528, 2007 [source]

A comparative study of oxygen transmission rates through polymer films based on fluorescence quenching

PACKAGING TECHNOLOGY AND SCIENCE, Issue 6 2010
I. Siró
Abstract Information on oxygen permeability through polymer films is essential for some applications, especially in food packaging where the control of oxygen levels can be critical in avoiding food spoilage. A permeability testing device using fluorescence-based optical oxygen sensing was developed as a potential new instrument for measuring the oxygen permeability of packaging films. The fluorescence-based permeability tester was validated against two existing commercial oxygen permeability measuring devices, the Mocon Ox-Tran 2/20 and PBI-Dansensor OPT-5000. Oxygen transmission rates (OTR) of polylactide (PLA) and nanoclay-reinforced PLA films, as well as polyethylene/poly(ethylene terephthalate) (PE/PET) and polypropylene/poly(ethylene terephthalate) (PP/PET) laminated films were determined at 23°C and 50% relative humidity using each of these instruments. No significant differences were observed between mean OTR values obtained by the fluorescence method and the corresponding values obtained using the OPT-5000 but significantly lower values were measured when using the Mocon Ox-Tran 2/20. In general, oxygen permeability data for the tested films were within the range of values found in the literature; however, in terms of further development, the fluorescence-based technique gave OTR with relatively high standard deviation compared to the commercial methods and equipment modifications to address this issue are considered desirable. Copyright © 2010 John Wiley & Sons, Ltd. [source]