scholarly journals Controlled Release of Thymol from Poly(Lactic Acid)-Based Silver Nanocomposite Films with Antibacterial and Antioxidant Activity

Antioxidants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 395 ◽  
Author(s):  
Marina Ramos ◽  
Ana Beltran ◽  
Elena Fortunati ◽  
Mercedes Peltzer ◽  
Francesco Cristofaro ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Controlled Release ◽  
Nanocomposite Films ◽  
Poly Lactic Acid ◽  
Spectroscopic Techniques ◽  
Ag Nps ◽  
Antibacterial Performance ◽  
Dpph Method ◽  
Potential Applications ◽  
Silver Nanocomposite

Thymol and silver nanoparticles (Ag-NPs) were used to develop poly(lactic acid) (PLA)-based films with antioxidant and antibacterial performance. Different amounts of thymol (6 and 8 wt%) and 1 wt% Ag-NPs were added to PLA to produce the active films. Ag-NPs and thymol were successfully identified in the nanocomposite structures using spectroscopic techniques. A kinetic study was performed to evaluate the release of thymol and Ag-NPs from the nanocomposites to an aqueous food simulant (ethanol 10%, v/v) at 40 °C. The diffusion of thymol from the polymer matrix was affected by the presence of non-migrating Ag-NPs, which showed non-Fickian release behavior. The ternary system including 1 wt% Ag-NPs and 8 wt% thymol showed clear antibacterial performance by reducing the cell viability of Escherichia coli and Staphylococcus aureus by around 40% after 3 and 24 h of storage at 4, 25, and 37 °C compared to neat PLA. Significant antioxidant behavior of all active films was also confirmed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The obtained nanocomposite films based on PLA and the addition of Ag-NPs and thymol were proven to have combined antioxidant and antibacterial performance, with controlled release of thymol. These formulations have potential applications in the development of innovative and customized active packaging systems to increase the shelf-life of food products.

Strong and ductile poly(lactic acid) nanocomposite films reinforced with alkylated graphene nanosheets

2015 ◽  
Vol 264 ◽  
pp. 538-546 ◽  
Author(s):  
Li Zhang ◽  
Yinfeng Li ◽  
Huanhuan Wang ◽  
Yadong Qiao ◽  
Jinzhou Chen ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Graphene Nanosheets ◽  
Nanocomposite Films ◽  
Poly Lactic Acid

scholarly journals Bonding Wood Veneer with Biobased Poly(Lactic Acid) Thermoplastic Polyesters: Potential Applications for Consolidated Wood Veneer and Overlay Products

Fibers ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 50
Author(s):  
Warren J. Grigsby ◽  
Arpit Puri ◽  
Marc Gaugler ◽  
Jan Lüedtke ◽  
Andreas Krause
Keyword(s):  
Tensile Strength ◽  
Lactic Acid ◽  
Cold Water ◽  
Performance Criteria ◽  
Poly Lactic Acid ◽  
Wood Veneer ◽  
Pressing Temperature ◽  
Strength Performance ◽  
Potential Applications ◽  
Laminated Panels

This study reports on the use of poly(lactic acid) (PLA) as a renewable thermoplastic adhesive for laminated panels using birch, spruce, and pine veneers. Consolidated panels were prepared from veneer and PLA foils by hot-pressing from 140 to 180 °C to achieve minimum bondline temperatures. Evaluation of panel properties revealed that the PLA-bonded panels met minimum tensile strength and internal bond strength performance criteria. However, the adhesion interface which developed within individual bondlines varied with distinctions between hardwood and softwood species and PLA grades. Birch samples developed greater bondline strength with a higher pressing temperature using semi-crystalline PLA, whereas higher temperatures produced a poorer performance with the use of amorphous PLA. Panels formed with spruce or pine veneers had lower bondline performance and were also similarly distinguished by their pressing temperature and PLA grade. Furthermore, the potential for PLA-bonded laminated panels was demonstrated by cold water soak testing. Samples exhibiting relatively greater bondline adhesion had wet tensile strength values comparable to those tested in dry state. Our study outcomes suggest the potential for PLA bonding of veneers and panel overlays with the added benefits of being renewable and a no added formaldehyde system.

scholarly journals Release of Graphene and Carbon Nanotubes from Biodegradable Poly(Lactic Acid) Films during Degradation and Combustion: Risk Associated with the End-of-Life of Nanocomposite Food Packaging Materials

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2346 ◽  
Author(s):  
Stanislav Kotsilkov ◽  
Evgeni Ivanov ◽  
Nikolay Vitanov
Keyword(s):  
Risk Assessment ◽  
Carbon Nanotubes ◽  
Lactic Acid ◽  
Food Packaging ◽  
Safety Concern ◽  
Barrier Properties ◽  
Nanocomposite Films ◽  
Poly Lactic Acid ◽  
Qualitative Risk Assessment ◽  
The Matrix

Nanoparticles of graphene and carbon nanotubes are attractive materials for the improvement of mechanical and barrier properties and for the functionality of biodegradable polymers for packaging applications. However, the increase of the manufacture and consumption increases the probability of exposure of humans and the environment to such nanomaterials; this brings up questions about the risks of nanomaterials, since they can be toxic. For a risk assessment, it is crucial to know whether airborne nanoparticles of graphene and carbon nanotubes can be released from nanocomposites into the environment at their end-life, or whether they remain embedded in the matrix. In this work, the release of graphene and carbon nanotubes from the poly(lactic) acid nanocomposite films were studied for the scenarios of: (i) biodegradation of the matrix polymer at the disposal of wastes; and (ii) combustion and fire of nanocomposite wastes. Thermogravimetric analysis in air atmosphere, transmission electron microscopy (TEM), atomic force microscopy (AFM) and scanning electron microscope (SEM) were used to verify the release of nanoparticles from nanocomposite films. The three factors model was applied for the quantitative and qualitative risk assessment of the release of graphene and carbon nanotubes from nanocomposite wastes for these scenarios. Safety concern is discussed in respect to the existing regulations for nanowaste stream.

Synthesis and Kinetic Studies on Controlled Release of 6-Thioguanine Entrapped Polyethylene Glycol-Co-Polylactic Acid Polymer Nanoparticles

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Sathishkumar Kannaiyan ◽  
T.G.Ashwin Narayanan ◽  
P.Karthick Sarathy ◽  
Nagarjun Sudhakar ◽  
Rama Krishnan
Keyword(s):  
Gold Nanoparticles ◽  
Lactic Acid ◽  
Polyethylene Glycol ◽  
Controlled Release ◽  
Drug Release ◽  
Kinetic Equations ◽  
Kinetic Studies ◽  
Poly Lactic Acid ◽  
Average Size

Poly lactic acid-polyethylene glycol (PLA-co-PEG) copolyester was synthesized from oligomer of L-lactic acid and poly ethylene glycol (PEG) using stannous octoate as catalyst. 6-Thioguanine containing Poly lactic acid-polyethylene glycol (PLA-co-PEG) nanocapsules were prepared in the presence and absence of gold nanoparticles via the W/O/W emulsification solvent-evaporation method. The morphologies of prepared nanocapsules changed substantially because of the presence of gold nanoparticles. From SEM and TEM measurements, the average size of the polymer nanocapsules and gold nanoparticles were found to be in range of 230-260 nm and 18-20 nm, respectively. In general the drug release was quicker in Phosphate buffer saline (pH 7.4) compared to 0.1M hydrochloric acid and this may be due to higher solubility, higher swelling and penetration properties of PLA-co-PEG in PBS compared to HCl. Polymer nanocapsules with gold show a prolonged controlled release with higher encapsulation efficiency (75%) compared to that of polymer nanocapsules (45%) in the absence of gold nanoparticles. It may be due to the more entrapping efficiency of gold and less diffusivity of drugs from the nanocapsules. Application of in vitro drug release data to various kinetic equations indicated Higuchi model, indicating a uniform distribution of thioguanine in the nanocapsules.

Drug delivery systems based on pharmaceutically active ionic liquids and biocompatible poly(lactic acid)

2014 ◽  
Vol 2 (20) ◽  
pp. 3133-3141 ◽  
Author(s):  
Claire Jouannin ◽  
Corine Tourné-Péteilh ◽  
Vincent Darcos ◽  
Tahmer Sharkawi ◽  
Jean-Marie Devoisselle ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Ionic Liquids ◽  
Lactic Acid ◽  
Controlled Release ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Poly Lactic Acid

API-ILs were encapsulated into biocompatible PLLA. The morphology and crystallinity of the resulting membranes can be tuned by varying the IL nature and content leading to controlled release.

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