Novel biopolimeric system for bone tissue engineering: Crosslinked and plasticized chitosan/poly vinyl alcohol/hydroxiapatite scaffolds

Porous scaffolds made of chitosan, polyvinyl alcohol and hydroxyapatite were prepared via freeze-drying method. In this matter, three different volume ratios of polymer solutions (1:1, 1:3, 3:1) and constant hydroxyapatite mass ratio were blended. Glutaraldehyde and glycerol were added as a polymer-chain crosslinker and plasticizer, respectively. The obtained scaffolds were used to test bone proliferation and potential for bone regeneration and they were characterized through FTIR, mechanical tests, cell cultures and swelling tests. Every quantitative measurement was statistically tested using two-way analysis of variance (ANOVA) with < 0.05. Partial results from cell culture have been obtained, showing faster cell differentiation in the scaffolds combined with glutaraldehyde and glycerol. Crosslinked scaffolds showed better swelling conditions than those that were not subject to this chemical reaction. Besides, samples with higher chitosan ratio exhibited better swelling behavior. Experiments suggest that the bio-polymeric system has potential for bone tissue regeneration. © 2018 IEEE.Universidad Manuela Beltran (Bogota, Colombia); Ministry of Education, Youth and Sports of the Czech Republic - Program NPU I [LO1504

Revista Temas Agrarios Volumen 26; Suplemento 1 de 2021

1st International and 2nd National Symposium of Agronomic Sciences: The rebirth of the scientific discussion space for the Colombian Agro.1 Simposio Intenacional y 2 Nacional de Ciencias Agronómicas: El renacer del espacio de discusión científica para el Agro colombiano

Delayed colorectal cancer care during covid-19 pandemic (decor-19). Global perspective from an international survey

Background The widespread nature of coronavirus disease 2019 (COVID-19) has been unprecedented. We sought to analyze its global impact with a survey on colorectal cancer (CRC) care during the pandemic. Methods The impact of COVID-19 on preoperative assessment, elective surgery, and postoperative management of CRC patients was explored by a 35-item survey, which was distributed worldwide to members of surgical societies with an interest in CRC care. Respondents were divided into two comparator groups: 1) ‘delay’ group: CRC care affected by the pandemic; 2) ‘no delay’ group: unaltered CRC practice. Results A total of 1,051 respondents from 84 countries completed the survey. No substantial differences in demographics were found between the ‘delay’ (745, 70.9%) and ‘no delay’ (306, 29.1%) groups. Suspension of multidisciplinary team meetings, staff members quarantined or relocated to COVID-19 units, units fully dedicated to COVID-19 care, personal protective equipment not readily available were factors significantly associated to delays in endoscopy, radiology, surgery, histopathology and prolonged chemoradiation therapy-to-surgery intervals. In the ‘delay’ group, 48.9% of respondents reported a change in the initial surgical plan and 26.3% reported a shift from elective to urgent operations. Recovery of CRC care was associated with the status of the outbreak. Practicing in COVID-free units, no change in operative slots and staff members not relocated to COVID-19 units were statistically associated with unaltered CRC care in the ‘no delay’ group, while the geographical distribution was not. Conclusions Global changes in diagnostic and therapeutic CRC practices were evident. Changes were associated with differences in health-care delivery systems, hospital’s preparedness, resources availability, and local COVID-19 prevalence rather than geographical factors. Strategic planning is required to optimize CRC care