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Laser-modified PLGA for implants: in vitro degradation and mechanical properties

Kobielarz Magdalena, Tomanik Magdalena, Mroczkowska Katarzyna, Szustakiewicz Konrad, Oryszczak Magdalena, Mazur Anna, Antończak Arkadiusz, Filipiak Jarosław

Acta of Bioengineering and Biomechanics

2020

Vol. 22, no. 1

179--192

Irradiations of poly(lactic-co-glycolic acid) surface by CO2 laser lead to alterations of physicochemical properties of the copolymer. Effects of PLGA irradiations depend on the process parameters determining different cases of surface modification. Hence the main goal of presented studies was to define the influence of CO2 laser irradiation with different process parameters, inducing three cases of surface modification, on mechanical properties and topography of PLGA during degradation in the aqueous environment. Methods: Hydrolytic degradation of untreated and treated by CO2 laser thin specimens of PLGA was performed in distilled (demineralized) water. Mechanical properties of PLGA specimens before and during incubation were conducted in accordance with the PN-EN ISO 527-3:1998 standard. The pH of incubation solutions, topographies, masses and geometrical dimensions of specimens were controlled during the process. Results: During the hydrolytic degradation, gradual changes in failure mode were observed from ductile failure characteristic for untreated PLGA to brittle failure of incubated PLGA regardless of the case of induced modification. Tensile strength decreased with degradation time regardless of the case of surface modification with insignificant fluctuation Young’s moduli at the level of means. The pH of solutions for each case decreased and topography od specimens become smoother with incubation time. Conclusions: PLGA surface modification by CO2 laser below the ablation threshold (P1) and at the ablation threshold (P2) led to surface functionalization, however, irradiation above the ablation threshold (P3) caused marked degradation of PLGA and accelerated specimens disintegration during incubation in the aquatic environment.

Formulation of nimesulide-loaded polylactide/poly(lactic-co-glycolic acid) nanoparticles and the evaluation of release kinetics

Pobudkowska A., Nosol K., Gierycz P., Domańska U.

Polimery

2018

T. 63, nr 9

586--593

Polymeric nanoparticles containing nimesulide (NIM) were prepared by the emulsion solvent evaporation method. Biodegradable polymers were used as materials for nanoparticle formulations with the application of studies for the drug delivery sector in mind. Two analytical methods, scanning electron microscopy (SEM) and particle size analysis, were applied to investigate the obtained nanoparticles. Characteristic parameters were calculated to describe the amount of active pharmaceutical ingredient trapped in nanoparticles. The biological active substance release process was investigated under different conditions. The impact of various parameters [kind of polymer (PLA or PLGA), speed of mixing and especially of pH] is presented across our research.

Polimerowe nanocząstki zawierające nimesulid (NIM) otrzymano metodą emulsyjną z odparowaniem rozpuszczalnika. Do ich wytworzenia wykorzystano biodegradowalne polimery. Wytworzone nanocząstki zbadano za pomocą skaningowej mikroskopii elektronowej (SEM) oraz analizatora wielkości cząstek. Obliczono charakterystyczne parametry opisujące ilość substancji farmaceutycznie aktywnej uwięzionej wewnątrz nanocząstek. Oceniono wpływ rodzaju polimeru stosowanego do kapsułkowania, szybkości mieszania suspensji, w szczególności pH środowiska na proces uwalniania substancji biologicznie czynnej.