RESUMEN
European and German directives for approval of new medical devices require tests for cytotoxicity in relevant media, since urine can influence cytotoxicity of biodegradable devices. The aim of this study was to determine the long-term cytotoxicity of PLGA-b-mPEG (PLGA-PEG) polymer carriers and artificial urine (AU) to human UROtsa cells. Benign urothelial UROtsa cells were incubated in fetal bovine serum-containing RPMI 1640 medium supplemented with a range of concentrations of AU for 24 h and 7 days. Cell viability was determined by the XTT assay and by live/dead staining. The cytotoxicity of medium containing degradation products from PLGA-PEG carriers was also tested on the UROtsa cells in AU-containing and control medium. PLGA-PEG carriers exhibited no cytotoxicity to UROtsa cells after 24 h of incubation. However, after 7 days, cytotoxicity was observed, but this was largely attributable to the effects of 30% AU on the cells. Compared to phosphate buffer saline (PBS) and normalized to RPMI 1640 medium, significant cytotoxicity was observed by 24 h in medium containing 50% AU and by 7 days in medium containing 30% AU. Live/Dead staining confirmed proliferation results and no pH-changes could be observed. Here we demonstrate for the first time the impact of AU on standard cytotoxicity tests related to biomaterials for urinary-tract applications. Our study showed cytotoxic effects of high concentrations of 50% AU by 24 h and by physiological concentrations of AU (i.e., 30%) by 7 days. We have also demonstrated that PLGA-PEG has no cytotoxic effects in the appropriate AU-containing test environment. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2140-2147, 2018.
Asunto(s)
Medios de Cultivo/química , Ensayo de Materiales , Polietilenglicoles , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Orina/química , Urotelio/metabolismo , Animales , Bovinos , Línea Celular Transformada , Humanos , Polietilenglicoles/química , Polietilenglicoles/farmacología , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/farmacología , Urotelio/citologíaRESUMEN
BACKGROUND: Guillain-Barré syndrome (GBS) as acute inflammatory demyelinating polyradiculoneuropathy frequently leads to lower urinary tract dysfunction. The available knowledge in the medical literature is limited and good recommendations for diagnosis and therapy are rare. MATERIALS AND METHODS: In this study, 189 patients with GBS were screened for lower urinary tract dysfunction. In symptomatic patients, a urodynamic study was performed. Detrusor contractility, post-void residual, and changes of the symptoms over time were studied. Overall Barthel index and urinary control Barthel index as well as the relationship of time after onset of the disease and post-void residual were studied as possible screening criteria for urodynamic assessment. RESULTS: According to the urinary control Barthel index (BI), 115 of 189 patients (61%) presented lower urinary tract symptoms sometime during the course of disease. In 28 patients, these symptoms were temporary during the acute phase. At the time of urological assessment, 87 patients had lower urinary tract symptoms. At the end of rehabilitation, 37 had no symptoms anymore (BI 10), 20 were able to control micturition to a certain extent (BI 5), and 30 had no lower urinary tract control (BI 0). There was a significant negative correlation between post-void residual volume and overall BI (ρ -0.5823, p < 0.0001) and BI for urinary tract control (ρ -0.6430, p < 0.0001). CONCLUSIONS: Overall BI and BI for urinary tract control are suitable screening criteria for urodynamic assessment.