Recovering and Exploiting Aragonite and Calcite Single Crystals with Biologically Controlled Shapes from Mussel Shells

Control over the shape and morphology of single crystals is a theme of great interest in fundamental science and for technological application. Many synthetic strategies to achieve this goal are inspired by biomineralization processes. Indeed, organisms are able to produce crystals with high fidelity in shape and morphology utilizing macromolecules that act as modifiers. An alternative strategy can be the recovery of crystals from biomineralization products, in this case, seashells. In particular, waste mussel shells from aquaculture are considered. They are mainly built up of single crystals of calcite fibers and aragonite tablets forming an outer and an inner layer, respectively. A simple mechanochemical treatment has been developed to separate and recover these two typologies of single crystals. The characterization of these single crystals showed peculiar properties with respect to the calcium carbonate from quarry or synthesis. We exploited these biomaterials in the water remediation field using them as substrate adsorbing dyes. We found that these substrates show a high capability of adsorption for anionic dye, such as Eosin Y, but a low capability of adsorption for cationic dyes, such as Blue Methylene. The adsorption was reversible at pH 5.6. This application represents just an example of the potential use of these biogenic single crystals. We also envision potential applications as reinforcing fillers and optical devices

Antimicrobial properties of chitosan from different developmental stages of the bioconverter insect Hermetia illucens

Growing antimicrobial resistance has prompted researchers to identify new natural molecules with antimicrobial potential. In this perspective, attention has been focused on biopolymers that could also be functional in the medical field. Chitin is the second most abundant biopolymer on Earth and with its deacetylated derivative, chitosan, has several applications in biomedical and pharmaceutical fields. Currently, the main source of chitin is the crustacean exoskeleton, but the growing demand for these polymers on the market has led to search for alternative sources. Among these, insects, and in particular the bioconverter Hermetia illucens, is one of the most bred. Chitin can be extracted from larvae, pupal exuviae and dead adults of H. illucens, by applying chemical methods, and converted into chitosan. Fourier-transformed infrared spectroscopy confirmed the identity of the chitosan produced from H. illucens and its structural similarity to commercial polymer. Recently, studies showed that chitosan has intrinsic antimicrobial activity. This is the first research that investigated the antibacterial activity of chitosan produced from the three developmental stages of H. illucens through qualitative and quantitative analysis, agar diffusion tests and microdilution assays, respectively. Our results showed the antimicrobial capacity of chitosan of H. illucens, opening new perspectives for its use in the biological area

Characterization of chitin and chitosan derived from Hermetia illucens, a further step in a circular economy process

Due to their properties and applications, the growing demand for chitin and chitosan has stimulated the market to find more sustainable alternatives to the current commercial source (crustaceans). Bioconverter insects, such as Hermetia illucens, are the appropriate candidates, as chitin is a side stream of insect farms for feed applications. This is the first report on production and characterization of chitin and chitosan from different biomasses derived from H. illucens, valorizing the overproduced larvae in feed applications, the pupal exuviae and the dead adults. Pupal exuviae are the best biomass, both for chitin and chitosan yields and for their abundance and easy supply from insect farms. Fourier-transform infrared spectroscopy, X-ray diffraction and scanning electron microscope analysis revealed the similarity of insect-derived polymers to commercial ones in terms of purity and structural morphology, and therefore their suitability for industrial and biomedical applications. Its fibrillary nature makes H. illucens chitin suitable for producing fibrous manufacts after conversion to chitin nanofibrils, particularly adults-derived chitin, because of its high crystallinity. A great versatility emerged from the evaluation of the physicochemical properties of chitosan obtained from H. illucens, which presented a lower viscosity-average molecular weight and a high deacetylation degree, fostering its putative antimicrobial properties

Preliminary investigation on the effect of insect-based chitosan on preservation of coated fresh cherry tomatoes

: Chitosan was produced from Hermetia illucens pupal exuviae by heterogeneous and homogeneous deacetylation. Tomato fruits (Solanum lycopersicum), that are one of the most grown and consumed food throughout the world, were coated with 0.5 and 1% chitosan, applied by dipping or spraying, and stored at room temperature or 4 °C, for a storage period of 30 days. Statistical analysis give different results depending on the analysed parameters: heterogeneous chitosan, indeed, had a better effect than the homogenous one in maintaining more stable physico-chemical parameters, while the homogenous chitosan improved the total phenols, flavonoids and antioxidant activity. Chitosan coatings applied by spraying were more effective in all the analyses. Chitosan derived from H. illucens always performed similarly to the commercial chitosan. However, a general better performance of insect-derived chitosan on the concentration of phenolics and flavonoids, and the antioxidant activity was observed as compared to the commercial one. Chitosan coating has already been successfully used for preservation of fresh fruits, as alternative to synthetic polymers, but this is the first investigation of chitosan produced from an insect for this application. These preliminary results are encouraging regarding the validation of the insect H. illucens as a source of chitosan

The PLANES study: a protocol for a randomised controlled feasibility study of the placental growth factor (PlGF) blood test-informed care versus standard care alone for women with a small for gestational age fetus at or after 32 + 0 weeks' gestation.

BackgroundStillbirth remains a major concern across the globe and in some high-resource countries, such as the UK; efforts to reduce the rate have achieved only modest reductions. One third of stillborn babies are small for gestational age (SGA), and these pregnancies are also at risk of neonatal adverse outcomes and lifelong health problems, especially when delivered preterm. Current UK clinical guidance advocates regular monitoring and early term delivery of the SGA fetus; however, the most appropriate regimen for surveillance of these babies remains unclear and often leads to increased intervention for a large number of these women. This pilot trial will determine the feasibility of a large-scale trial refining the risk of adverse pregnancy outcome in SGA pregnancies using biomarkers of placental function sFlt-1/PlGF, identifying and intervening in only those deemed at highest risk of stillbirth.MethodsPLANES is a randomised controlled feasibility study of women with an SGA fetus that will be conducted at two tertiary care hospitals in the UK. Once identified on ultrasound, women will be randomised into two groups in a 3:1 ratio in favour of sFlt-1/PlGF ratio led management vs standard care. Women with an SGA fetus and a normal sFlt-1/PlGF ratio will have a repeat ultrasound and sFlt-1/PlGF ratio every 2 weeks with planned birth delayed until 40 weeks. In those women with an SGA fetus and an abnormal sFlt-1/PlGF ratio, we will offer birth from 37 weeks or sooner if there are other concerning features on ultrasound. Women assigned to standard care will have an sFlt-1/PlGF ratio taken, but the results will be concealed from the clinical team, and the woman's pregnancy will be managed as per the local NHS hospital policy. This integrated mixed method study will also involve a health economic analysis and a perspective work package exploring trial feasibility through interviews and questionnaires with participants, their partners, and clinicians.DiscussionOur aim is to determine feasibility through the assessment of our ability to recruit and retain participants to the study. Results from this pilot study will inform the design of a future large randomised controlled trial that will be adequately powered for adverse pregnancy outcome. Such a study would provide the evidence needed to guide future management of the SGA fetus.Trial registrationISRCTN58254381 . Registered on 4 July 2019

L’insetto Hermetia illucens: una fonte sostenibile di molecole di elevato valore biologico ed economico

Ad oggi, la crescente domanda mondiale di fonti proteiche per l'allevamento di animali non può più essere soddisfatta dalla pesca intensiva per la produzione di farine di pesce ad alto contenuto proteico, né dall'uso intensivo di terreni per colture proteiche (soia). Le proteine di insetto svolgono un ruolo importante nella sostituzione progressiva della soia e della farina di pesce e, in prospettiva, nella progressiva integrazione come nuovo alimento. Allevare insetti determina minori emissioni di gas serra e minore impronta idrica per grammo di proteine prodotte rispetto a qualsiasi altro allevamento convenzionale. Inoltre, alcuni insetti si nutrono di scarti organici. È il caso del dittero Hermetia illucens, un insetto saprofago in grado di bioconvertire scarti organici e sottoprodotti di origine vegetale, le cui larve e farine e proteine animali trasformate possono essere impiegate nella mangimistica per acquacoltura (Reg. EU 893/2017). Il processo di bioconversione, legato alla valorizzazione degli scarti agroalimentari, consente anche di ottenere prodotti secondari di elevato valore biologico ed economico, tra i quali lipidi e chitina. Le larve di H. illucens hanno un contenuto in lipidi pari a circa il 39% della biomassa larvale, ma è variabile in relazione al substarto alimentare. Per la loro composizione (acidi grassi saturi: acido laurico, miristico, palmitico e stearico, e insaturi: esadecenoico e ottadecenoico) i lipidi derivanti da H. illucens trovano impiego tal quali in mangimistica e opportunamente funzionalizzati per la produzione di biodiesel, additivi vegetali delle plastiche e per la formulazione di prodotti adatti alla cura personale (saponi, detergenti, shampoo). La chitina e i suoi derivati per le loro proprietà, come biodegradabilità, biocompatibilità, non tossicità, adsorbimento, trovano molte applicazioni in campo industriale e biomedico. Inoltre, grazie alle loro interessanti attività biologiche (antifungine, antibatteriche, antitumorali, immunoadiuvanti, antitrombogenici, anticolesterolemici) e alla bioadesività, sono ampiamente utilizzati come promotori dell'assorbimento ed agenti idratanti, nonché per la produzione di film e per la guarigione delle ferite. La chitina può essere trasformata, a seconda dell'applicazione prevista, in diverse conformazioni come nanofibrille, polveri, pellicole, gel e capsule. Le loro applicazioni includono usi in una varietà di settori, come l'industria alimentare, il trattamento delle acque reflue, l'agricoltura, l'ingegneria dei tessuti, i cosmetici, le applicazioni farmaceutiche e mediche, la produzione di carta e tessuti. Il processo di bioconversione dei sottoprodotti dell’agroalimentare mediato da H. illucens è uno strumento valido per la valorizzazione degli scarti e per la produzione sostenibile di proteine animali alternative e innovative da utilizzare come novel feed e, in prospettiva, novel food, e per la produzione di molecole (lipidi e chitina) di elevato valore economico, in ottica di economia circolar

Socio-cultural and clinician determinants in the maternal decision-making process in the choice for trial of labor vs. elective repeated cesarean section: A questionnaire comparison between Italian settings

To identify socio-cultural and clinician determinants in the decision-making process in the choice for trial of labor after cesarean (TOLAC) or elective repeat cesarean section (ERCS) in delivering women. A tailored questionnaire focused on epidemiological, socio-cultural and obstetric data was administered to 133 patients; of these, 95 were admitted for assistance at birth at Fondazione Policlinico Universitario "A. Gemelli" (FPG) IRCCS, Rome, and 38 at S. Chiara Hospital (SCH), Trento, Italy. Descriptive analysis and logistic regression modeling were performed. Vaginal birth after cesarean (VBAC) rates were higher at SCH than at FPG (68.4% vs. 23.2%; P < 0.05). Maternal age in the TOLAC/VBAC group was significantly higher at SCH than at FPG (37.1 vs. 34.9 years, P < 0.05). High levels of education and no-working condition corresponded to a lower rate of VBAC. Proposal on delivery mode after a previous CS was missed in the majority of cases. Participation in prenatal course was significantly less among women in the ERCS groups. Using logistic regression, the following determinants were found to be statistically significant in the decision-making process: maternal age [odds ratio (OR) = 0.968 (95% confidence interval [CI] 0.941-0.999); P = 0.019], education level [OR = 0.618 (95% CI 0.419-0.995); P = 0.043], information received after the previous CS [OR = 0.401 (95% CI 0.195-1.252); P = 0.029], participation in antenatal courses [OR = 0.534 (95% CI 0.407-1.223); P = 0.045] and self-determination in attempting TOLAC [OR = 0.756 (95% CI 0.522-1.077); P = 0.037]. In the attempt to promote person-centered care, increases in TOLAC/VBAC rates could be achieved by focusing on individual maternal needs. An ad hoc strategy for making birth safer should begin from accurate information at the time of the previous CS