Swelling kinetics and impregnation of PLA with thymol under supercritical CO2 conditions

Milovanović, Stoja; Kuska, Robert; Škorić-Lučić, Marija Lj.; Kalagasidis-Krušić, Melina T.; Frerich, Sulamith; Žižović, Irena; Ivanović, Jasna

doi:10.5937/tehnika1601016m

Cited by 11 publications

(6 citation statements)

References 11 publications

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“…However, the samples that were treated with scCO 2 at just 100 bar while the temperature was increased from 35 until 55 °C demonstrated a lesser swelling effect. In accordance, Milovanovic et al [ 5 ] studied the swelling pattern of PLA cylinders, which had been previously produced from melted PLA beads, under scCO 2 at 100 bar, and they observed that temperature increments (40–75 °C) diminished the swelling effect.…”

Section: Discussionmentioning

confidence: 60%

“…Polyesters, and specially polylactic acid (PLA) in its poly-l-lactide (PLLA) and poly-d,l-lactide (PDLLA) forms, are the most widely studied polymers for the development of bioresorbable drug-delivering implantable devices. Some examples can be found in the literature regarding the supercritical impregnation of drugs or bioactive substances into lactic acid polymers shaped as films, thin discs [ 4 , 5 , 6 ], microparticles [ 7 ], or porous structures [ 8 , 9 , 10 , 11 ]. However, no references have been found to use supercritical impregnation on PLA filaments, despite some studies having been conducted on this type of impregnation into surgical suture materials [ 12 , 13 , 14 ].…”

Section: Introductionmentioning

confidence: 99%

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Supercritical Impregnation of Ketoprofen into Polylactic Acid for Biomedical Application: Analysis and Modeling of the Release Kinetic

et al. 2021

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Ketoprofen (KET) is an anti-inflammatory drug often used in medicine due to its analgesic and antipyretic effects. If it is administered in a controlled form by means of different dosing devices, it acts throughout the patient’s recovery period improving its efficacy. This study intends to support the use of supercritical solvent impregnation (SSI) as an efficient technique to develop polylactic acid (PLA) functionalized with ketoprofen, for use as controlled drug release devices. For this purpose, firstly, the influence of different SSI variables on the desirable swelling of the polymer structure, while avoiding their foaming, were evaluated. Then, the resulting ketoprofen loading was evaluated under different pressure/temperature conditions. It was generally found that as pressure and temperature are higher, the drug impregnation loads also increase. The maximum impregnation loads (at about 9% KET/PLA) were obtained at 200 bar and 75 °C. In vitro drug release tests of the impregnated compound were also carried out, and it was found that drug release profiles were also dependent on the specific pressure and temperature conditions used for the impregnation of each polymer filament.

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Section: Discussionmentioning

confidence: 60%

Section: Introductionmentioning

confidence: 99%

Supercritical Impregnation of Ketoprofen into Polylactic Acid for Biomedical Application: Analysis and Modeling of the Release Kinetic

et al. 2021

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“…However, when T

is around the working conditions, the polymer can be still in the glassy state [ 39 ], although some volume variations can occur. To evaluate these mechanical changes, the percentage of volume increment or swelling of the filament according to the equation given below [ 40 ], where

is the swelling percentage, V is filament volume after the impregnation, and

is the original filament volume before being impregnated:

…”

Section: Methodsmentioning

confidence: 99%

Supercritical Impregnation of PLA Filaments with Mango Leaf Extract to Manufacture Functionalized Biomedical Devices by 3D Printing

et al. 2021

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Polylactic Acid (PLA) filaments impregnated with ethanolic mango leaves extract (MLE) with pharmacological properties were obtained by supercritical impregnation. The effects of pressure, temperature and amount of extract on the response variables, i.e., swelling, extract loading and bioactivity of the PLA filaments, were determined. The analysis of the filaments biocapacities revealed that impregnated PLA filaments showed 11.07% antidenaturant capacity and 88.13% antioxidant activity, which after a 9-day incubation shifted to 30.10% and 9.90%, respectively. Subsequently, the same tests were conducted on printed samples. Before their incubation, the printed samples showed 79.09% antioxidant activity and no antidenaturant capacity was detected. However, after their incubation, the antioxidant activity went down to only 2.50%, while the antidenaturant capacity raised up to 23.50%. The persistence of the bioactive properties after printing opens the possibility of using the functionalized PLA filaments as the feed for a three-dimensional (3D) printer.

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“…PDLLA swells in scCO 2 and forms a homogeneous polymer column at the bottom of the tube. Further, we can assume that the diffusion of the CO 2 in PDLLA and the swelling of PDLLA are orders of magnitude faster than TEMPONE diffusion in swollen PDLLA [ 86 , 87 , 88 ], and we can suppose the areas achieved by the probe to be completely swollen. The diffusion of TEMPONE in PDLLA hence could be described as non-stationary one-component diffusion into a plane sheet from a medium with constant solute concentration.…”

Section: Methodsmentioning

confidence: 99%

Solute Diffusion into Polymer Swollen by Supercritical CO2 by High-Pressure Electron Paramagnetic Resonance Spectroscopy and Chromatography

et al. 2021

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High-pressure electron paramagnetic resonance (EPR) was used to measure translational diffusion coefficients (Dtr) of a TEMPONE spin probe in poly(D,L-lactide) (PDLLA) and swollen in supercritical CO2. Dtr was measured on two scales: macroscopic scale (>1 μm), by measuring spin probe uptake by the sample; and microscopic scale (<10 nm), by using concentration-dependent spectrum broadening. Both methods yield similar translational diffusion coefficients (in the range 5–10 × 10−12 m2/s at 40–60 °C and 8–10 MPa). Swollen PDLLA was found to be homogeneous on the nanometer scale, although the TEMPONE spin probe in the polymer exhibited higher rotational mobility (τcorr = 6 × 10−11 s) than expected, based on its Dtr. To measure distribution coefficients of the solute between the swollen polymer and the supercritical medium, supercritical chromatography with sampling directly from the high-pressure vessel was used. A distinct difference between powder and bulk polymer samples was only observed at the start of the impregnation process.

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Swelling kinetics and impregnation of PLA with thymol under supercritical CO2 conditions

Abstract: The present work was aimed to study swelling kinetics of polylactic acid (PLA)

Cited by 11 publications

References 11 publications

Supercritical Impregnation of Ketoprofen into Polylactic Acid for Biomedical Application: Analysis and Modeling of the Release Kinetic

Supercritical Impregnation of Ketoprofen into Polylactic Acid for Biomedical Application: Analysis and Modeling of the Release Kinetic

Supercritical Impregnation of PLA Filaments with Mango Leaf Extract to Manufacture Functionalized Biomedical Devices by 3D Printing

Solute Diffusion into Polymer Swollen by Supercritical CO2 by High-Pressure Electron Paramagnetic Resonance Spectroscopy and Chromatography

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