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Within the context of paving the way for a sustainable bioeconomy, there is a strong emphasis on utilizing bio-based raw materials as substitutes for fossil fuels in the production of polymers. When designing the synthesis of novel polymeric materials from bio-based building blocks, a promising green approach consists in utilizing enzymes as biocatalysts. This aspect is particularly important when aiming to obtain products from the class of polyesters and polyesteramides with biocompatible and biodegradable properties, as enzymes facilitate the synthesis of polymers that align closely with biological systems. Lipases have been proven to be very effective in the synthesis of polymers, particularly in the ring-opening polymerization of ε-caprolactone. Considering the possibility of performing the copolymerization of ε-caprolactone for obtaining random and block structures, this is the first comparative study of the enzymatic polymer synthesis utilizing an innovative approach of combining ring-opening polymerization with polycondensation. Terpolymers derived from ε-caprolactone and dimethyl itaconate or dimethyl adipate with either 1,8-octanediol or 1,8-octanediamine were obtained at 85 °C in a solventless systems, yielding products with a copolymer content of >85 % and weight-average molecular weight (M w ) up to 40,000 Da. The thermal properties and biodegradation behavior of the synthetized terpolymers were assessed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Objective/background: Asymmetric dimethylarginine (ADMA) inhibits nitric oxide (NO) synthesis and is a marker of atherosclerosis. This study examined the correlation between pre-operative l-arginine and ADMA concentration during carotid endarterectomy (CEA), and jugular lactate indicating anaerobic cerebral metabolism, jugular S100B reflecting blood-brain barrier integrity, and with factors of surgical intervention., Methods: The concentration of l-arginine, ADMA, and symmetric dimethylarginine was measured in blood taken under regional anaesthesia from the radial artery of 55 patients prior to CEA. Blood gas parameters, concentration of lactate, and S100B were also serially measured in blood taken from both the radial artery and the jugular bulb before and after carotid clamping, and after release of the clamp. To estimate anaerobic metabolism, the jugulo-arterial ratio of CO 2 gap/oxygen extraction was calculated., Results: Positive correlation was found between pre-operative ADMA levels and the ratio of jugulo-arterial CO 2 gap/oxygen extraction during clamp and reperfusion (p = .005 and p = .01, respectively). An inverse correlation was found between the pre-operative l-arginine concentration and jugular lactate at each time point (both p = .002). The critical pre-operative level of l-arginine was determined by receiver operator curve analysis. If l-arginine was below the cutoff value of 35 μmol/L, jugular S100B concentration was higher 24 h post-operatively (p = .03), and jugular lactate levels were increased during reperfusion (p = .02). The median pre-operative concentration of l-arginine was lower in patients requiring an intra-operative shunt than in patients without need of shunt (median: 30.3 μmol/L [interquartile range 24.4-34.4 μmol/L] vs. 57.6 μmol/L [interquartile range 42.3-74.5 μmol/L]; p = .002)., Conclusion: High pre-operative ADMA concentration predicts poor cerebral perfusion indicated by elevated jugulo-arterial CO 2 gap/oxygen extraction. Low pre-operative l-arginine concentration predicts the need for a shunt. The inverse correlation between pre-operative l-arginine concentration and both jugular lactate and S100B during carotid clamping suggests a protective role of the NO donor l-arginine., (Copyright © 2016 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)