4D printing of biodegradable elastomers with tailorable thermal response at physiological temperature.

4D printing has a great potential for the manufacturing of soft robotics and medical devices. The alliance of digital light processing (DLP) 3D printing and novel shape-memory photopolymers allows for the fabrication of smart 4D-printed medical devices in high resolution and with tailorable functionalities. However, most of the reported 4D-printed materials are nondegradable, which limits their clinical applications. On the other hand, 4D printing of biodegradable shape-memory elastomers is highly challenging, especially when transition points close to physiological temperature and shape fixation under ambient conditions are required. Here, we report the 4D printing of biodegradable shape-memory elastomers with tailorable transition points covering physiological temperature, by using poly(D,L-lactide-co-trimethylene carbonate) methacrylates at various monomer feed ratios. After the programming step, the high-resolution DLP printed stents preserved their folded shape at room temperature, and showed efficient shape recovery at 37 °C. The materials were cytocompatible and readily degradable under physiological conditions. Furthermore, drug-loaded devices with tuneable release kinetics were realized by DLP-printing with resins containing polymers and levofloxacin or nintedanib. This study offers a new perspective for the development of next-generation 4D-printed medical devices.

[Granulomatous hepatitis in cytomegalovirus infection in healthy adults]. / Les hépatites granulomateuses au cours des infections à cytomégalovirus chez l'adulte sain.

The authors report 16 cases of cytomegalovirus (CMV) disease in previously healthy adults. Constant features included pyrexia lasting 3 to 8 weeks and mononucleosis occurring 2-3 weeks after the onset of fever. Moderate hepatomegaly without jaundice, splenomegaly and morbilliform or petechial rush were observed in 30 to 50 p. 100 of cases. None had pharyngitis. Mild increase in serum transaminase activity (2 to 5 N) was present in 13 of the 16 patients, but increased alkaline phosphatase activity was observed in only 3 of them. Liver biopsy was obtained in 10 patients. Liver lesions were characterised by the association of intra lobular granuloma, abundant mononuclear cells in the sinusoids and hepatic peri-venous inflammation but hepatocellular necrosis was not prominent. Typical intracellular inclusions were not seen, either in hepatocytes or in cells of biliary ducts. The diagnosis was ascertained by positive viremia and or viruria and presence of IgM antibodies. The outcome was favourable although clinical and biological signs lasted for about 8 weeks. The authors conclude that adults with chronic pyrexia, no pharyngitis and sub-clinical hepatitis with mild increases in transaminase activity and histologic mononucleosis hepatitis showing mononuclear infiltrates and granuloma formation are likely to have CMV disease.