New substrates for reliable enzymes: enzymatic modification of polymers

Recent studies clearly indicate that the modification of synthetic and natural polymers with enzymes is an environmentally friendly alternative to chemical methods using harsh conditions. New processes using lipases, proteases, nitrilases and glycosidases have been developed for the specific non-destructive functionalization of polymer surfaces. The specificity of enzymes has also been exploited in polymer synthesis; for example, lipases have been used for the production of optically active polyesters. Oxidoreductases have been used for the cross-linking and grafting of lignaceous materials and for the production of polymers from phenolics. Recent successes in this area are mainly attributable to advances in the design of reaction systems (e.g. biphasic systems and micellar solutions), while the enzymes are mainly from commercial sources

Enzymes go big : surface hydrolysis and functionalisation of synthetic polymers

Enzyme technology has progressed from the biotransformation of small substrates to biotransformation of synthetic polymers. Important breakthroughs have been the isolation and design of novel enzymes with enhanced activity on synthetic polymer substrates. These were made possible by efficient screening procedures and genetic engineering approaches based on an in-depth understanding of the mechanisms of enzymes on synthetic polymers. Enhancement of the hydrophilicity of synthetic polymers is a key requirement for many applications, ranging from electronics to functional textile production. This review focuses on enzymes that hydrolyse polyalkyleneterephthalates, polyamides or polyacrylonitriles, specifically on the polymer surface thereby replacing harsh chemical processes currently used for hydrophilisation

Análise dos Alertas Sobre os Dispositivos Médicos Emitidos pela Agência Portuguesa do Medicamento: Delineando o Propósito de Novas Recomendações Regulatórias

Introduction: Medical devices are healthcare technologies with a significantly growing market worldwide. This study aims to analyze medical device alerts issued by the Portuguese Medicines Agency, INFARMED, I.P. during 2017, as well as to identify the respective regulatory actions and to suggest additional recommendations. Material and Methods: All alerts on medical device alerts publicly available in the website of INFARMED, I.P. were identified and analyzed, including actions taken. Additionally, reports on medical devices from the Portuguese national competent authorities were compared with reports from other European Union member states such as Germany. Results: A total of 32 safety alerts were identified: 18 (56%) related with devices without identified records of commercialization in Portugal, six (19%) related with devices voluntarily withdrawn from the market, such as counterfeit products, and eight (25%) categorized as ‘other’. In both Portugal and Germany, 0.28 and 4.53 reports of national competent authorities per million inhabitants were identified, respectively. Diverse regulatory actions were taken, such as six compulsory indications to not acquire or use devices. Discussion: Considering that the European Union is an open market where citizens should have equal access to medical devices, the Portuguese system of medical device safety alerts seems to be functioning normally. The identified safety alerts seemed relevant, with Portugal registering a proportionally slightly lower number of alerts when compared with higher sales volume markets, which may be explained by an underreporting of this type of problems. Further studies are needed to confirm these preliminary results, although the development of databases comprising data on patients using medical devices is recommended in order to generate automatic email and text message alerts. Conclusion: A limited number of safety alerts on medical devices was identified in Portugal, with few reported cases of counterfeit or falsified devices. The Portuguese Medicines Agency contributes to the citizens’ access to quality medical devices, by issuing safety alerts, recommendations and mandatory market withdrawals for unsuitable or unsafe medical devices.Fundação para a Ciência e a Tecnologia (FCT) project UID/DTP/04567/2016.info:eu-repo/semantics/publishedVersio

Edible coatings enriched with essential oils and their compounds for fresh and fresh-cut fruit

Fresh fruit and vegetables consumption has increased in the past few years due to the enhanced awareness of consumers for healthy food. However, these products are highly perishable, and losses can be of great significance if postharvest correct management is not provided. Fresh-cut products are of increasing importance, since they are presented to the consumer in a state that allows for direct and immediate consumption. However, those products are even more perishable since cutting can induce a series of senescence associated responses to wounding, and are more susceptible to microbial spoilage. Edible coatings, which intend to reduce ripening processes and protect the fruit from water loss and spoilage may be a good way to enhance the shelf life of these products. More recently, the inclusion of additives into these edible coatings to increase their effectiveness, such as essential oils and their constituents with antimicrobial and antioxidant activities, has been reported and patented. © 2012 Bentham Science Publishers

"In Situ" enzymatically prepared polymers for wool coloration

Phenolic compounds such as hydroquinone, catechol and ferulic acid can polymerise and therefore develop deep colours when treated with peroxidase and laccase enzymes. We have attempted to apply this phenomenon for wool dyeing. Wool was padded with phenolic compounds and deep colours were developed by enzymatic treatment in buffer solutions. Mordant with chromium compounds or heating under the conditions of acid catalysis was available for fixation of these coloured compounds on the wool fibres.Enzymatically dyed wool samples.[GRAPHICS

Enzymes in fibre processing

[Excerpt] Advances in enzymology, genetics and industrial enzyme production make existing technologies using enzymes for fibre processing more attractive and open up new possibilities such as the improvement of synthetic fibers. Together with increasing knowledge about fibre morphology, more efficient processing and higher product quality become feasible. The 3rd International Conference on Biotechnology in the Textile Industry INTB04 held in Graz, Austria from June 13 /16 2004 provided a thorough overview of the current and future focus of enzymology in the materials processing industry. It stimulated discussions between experts from universities, research organizations and industry worldwide. Over 150 participants from 32 countries in 4 continents (one third of all participants coming from industry) ensured that this meeting had a strong impact in the area of biotechnology in materials processing. [...](undefined

Enzymatic polymerization of phenolic compounds

Phenolics are natural compounds which contains hydroxyl group bonded to aromatic hydrocarbon ring. These compounds can be divided into two categories depending on the oxidation state of the central pyran ring: flavonoids and non-flavonoids. It is important to highlight the excellent properties of the phenolic compounds, such as anti-inflammatory, antimicrobial, and antioxidant activity. It has been described that the oxidation of phenolic compounds enhances its antimicrobial properties since the resulting polymers can contribute to the microorganism’s toxification. The polymerization reaction can be achieved by different biocatalysts such as oxidoreductases, namely laccases and peroxidases. Laccases use molecular oxygen as a co-substrate, being therefore the perfect co-substrate. Depending on the structure of the phenolic compound, namely the number of hydroxyl groups, the enzymatic polymerization can be performed via laccase or using laccase-mediator systems (LMSs). On the first reaction, the phenolic compound is oxidized and the resulting phenoxy radicals conduct to polymers formation through recombination processes. On the second method, the phenolic compound oxidation is mediated by redox species yielding the polyphenols formation. Any of these two routes allows the polymerization of phenolic products with enhanced properties

Effect of a peptide in cosmetic formulations for hairhumidity-control

Humidity affects hair by changing the surface texture of the fiber. In higher humidity conditions, it is verified an increase of water uptake, which causes the swelling of the hair fibers. This leads to the extension of the hair cuticles and consequent increased friction between fibers, which causes static and an increase in the volume of hair tresses. However, these changes are distinct in different types of ethnic hair, where Caucasian Brown hair evidences a higher increase in hair tresses volume. We tested the application of several climate control formulations with and without a keratinbased peptide. The hair tresses treated with the formulations containing the peptide showed reduced volume change even after several hours of high humidity conditions. Due to its chemical nature, the peptide has affinity towards the hair fiber providing long-lasting moisture resistance and allowing it application in climate control formulations

Medical Termination of Delayed Miscarriage: Four-Year Experience with an Outpatient Protocol

Purpose: To evaluate the efficacy of an outpatient protocol with vaginal misoprostol to treat delayed miscarriage. Methods: Retrospective analysis of prospectively collected data on women medically treated for missed abortion with an outpatient protocol. The inclusion criteria were: ultrasound-based diagnosis of missed abortion with less than 10 weeks; no heavy bleeding, infection, inflammatory bowel disease or misoprostol allergy; no more than 2 previous spontaneous abortions; the preference of the patient regarding the medical management. The protocol consisted of: 1) a single dose of 800 µg of misoprostol administered intravaginally at the emergency department, after which the patients were discharged home; 2) clinical and ultrasonographic evaluation 48 hours later – if the intrauterine gestational sac was still present, the application of 800 µg of vaginal misoprostol was repeated, and the patients were discharged home; 3) clinical and ultrasonography evaluation 7 days after the initiation of the protocol – if the intrauterine gestational sac was still present, surgical management was proposed. The protocol was introduced in January 2012. Every woman received oral analgesia and written general recommendations. We also gave them a paper form to be presented and filled out at each evaluation. Results: Complete miscarriage with misoprostol occurred in 340 women (90.2%). Surgery was performed in 37 (9.8%) patients, representing the global failure rate of the protocol. Miscarriage was completed after the first misoprostol administration in 208 (55.2%) women, with a success rate after the second administration of 78.1% (132/169). The average age of the women with complete resolution using misoprostol was superior to the average age of those who required surgery (33.99 years versus 31.74 years; p = 0.031). Based on the ultrasonographic findings in the first evaluation, the women diagnosed with fetal loss achieved greater success rates compared with those diagnosed with empty sac (p = 0.049). Conclusions: We conclude this is an effective and safe option in the majority of delayed miscarriage cases during the first trimester, reducing surgical procedures and their consequences