Polydioxanone (PPDX), as an FDA approved polymer in tissue engineering, is an important component of some promising medical devices, e.g., biodegradable stents. The hydrolytic degradation of polydioxanone stents plays a key role in the safety and efficacy of treatment. A new fast and convenient method to quantitatively evaluate the hydrolytic degradation of PPDX stent material was developed. PPDX esophageal stents were degraded in phosphate-buffered saline for 24 weeks. For the first time, the changes in Raman spectra during PPDX biodegradation have been investigated here. The level of PPDX hydrolytic degradation was determined from the Raman spectra by calculating the area under the 1732 cm-1 peak shoulder. Raman spectroscopy, unlike Fourier transform infrared (FT-IR) spectroscopy, is also sensitive enough to monitor the decrease in the dye content in the stents during the degradation. Observation by a scanning electron microscope showed gradually growing cracks, eventually leading to the stent disintegration. The material crystallinity was increasing during the first 16 weeks, suggesting preferential degradation of the amorphous phase. Our results show a new easy and reliable way to evaluate the progression of PPDX hydrolytic degradation. The proposed approach can be useful for further studies on the behavior of PPDX materials, and for clinical practice.

• Klíčová slova
• Raman spectrum, biodegradable polymer, crack growth, hydrolytic degradation, polydioxanone, stent,
• Publikační typ
• časopisecké články MeSH

Biodegradable polymers are promising materials for use in medical applications such as stents. Their properties are comparable to commercially available resistant metal and polymeric stents, which have several major problems, such as stent migration and stent clogging due to microbial biofilm. Consequently, conventional stents have to be removed operatively from the patient's body, which presents a number of complications and can also endanger the patient's life. Biodegradable stents disintegrate into basic substances that decompose in the human body, and no surgery is required. This review focuses on the specific use of stents in the human body, the problems of microbial biofilm, and possibilities of preventing microbial growth by modifying polymers with antimicrobial agents.

• Klíčová slova
• antimicrobial agents, antimicrobial effects, biodegradable polymer, medicine, polylactide, stent,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

OBJECTIVES: To assess mid-term outcome of biodegradable biliary stents (BBSs) to treat benign biliary strictures refractory to standard bilioplasty. METHODS: Institutional review board approval was obtained and patient consent was waived. 107 patients (61 males, 46 females, mean age 59 ± 16 years), were treated. Technical success and complications were recorded. Ninety-seven patients (55 males, 42 females, aged 57 ± 17 years) were considered for follow-up analysis (mean follow-up 23 ± 12 months). Fisher's exact test and Mann-Whitney U tests were used and a Kaplan-Meier curve was calculated. RESULTS: The procedure was always feasible. In 2/107 cases (2 %), stent migration occurred (technical success 98 %). 4/107 patients (4 %) experienced mild haemobilia. No major complications occurred. In 19/97 patients (18 %), stricture recurrence occurred. In this group, higher rate of subsequent cholangitis (84.2 % vs. 12.8 %, p = 0.001) and biliary stones (26.3 % vs. 2.5 %, p = 0.003) was noted. Estimated mean time to stricture recurrence was 38 months (95 % C.I 34-42 months). Estimated stricture recurrence rate at 1, 2, and 3 years was respectively 7.2 %, 26.4 %, and 29.4 %. CONCLUSION: Percutaneous placement of a BBS is a feasible and safe strategy to treat benign biliary strictures refractory to standard bilioplasty, with promising results in the mid-term period. KEY POINTS: • Percutaneous placement of a BBS is 100 % feasible. • The procedure appears free from major complications, with few minor complications. • BBSs offer promising results in the mid-term period. • With a BBS, external catheter/drainage can be removed early. • BBSs represent a new option in treating benign biliary stenosis.

• Klíčová slova
• Biliary stricture, Bioabsorbable biliary stent, Percutaneous transhepatic bilioplasty, Percutaneous transhepatic cholangiography,
• MeSH
• implantace protézy * MeSH
• lidé středního věku MeSH
• lidé MeSH
• následné studie MeSH
• nemoci žlučového ústrojí chirurgie   MeSH
• recidiva MeSH
• retrospektivní studie MeSH
• stenóza chirurgie   MeSH
• stenty * MeSH
• vstřebatelné implantáty * MeSH
• výsledek terapie MeSH
• žlučové ústrojí MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH