Selective Laser Sintering versus Multi Jet Fusion: A Comprehensive Comparison Study Based on the Properties of Glass Beads-Reinforced Polyamide 12

Selective laser sintering (SLS) and multi jet fusion (MJF) are the most widespreadpowder bed fusion additive manufacturing techniques for fabricating polymericparts since they offer great designflexibility, productivity, and geometricalaccuracy. However, these technologies differ in the thermal energy source usedto melt the powders as well as the innovative use of printing agents featured inthe latter one to promote material consolidation and to avoid thermal bleeding atthe part contours. The use of a single powder made of glass beads-reinforcedpolyamide 12 (PA12/GB) for the fabrication of MJF and SLS samples makespossible a systematic comparison of the printed parts properties. A thoughtfulanalysis of the microstructure and mechanical properties of the samples revealsdifferences and peculiarities between the two technologies. SLS exhibits lowerporosity and higher mechanical performances when the parts are printed alongthe build plane thanks to the powerful heating ensured by the laser. In contrast,MJF samples show higher mechanical isotropy with greatflexural and tensilebehavior for vertically oriented parts. The role of glass beads in the materialbehavior is defined by their mechanical properties, meaning higher rigidity andlower strength compared to neat PA12, and fracture mechanism

Surfactant lung delivery with LISA and InSurE in adult rabbits with respiratory distress

Background In preterm infants, InSurE (Intubation–Surfactant–Extubation) and LISA (less invasive surfactant administration) techniques allow for exogenous surfactant administration while reducing lung injury associated with mechanical ventilation. We compared the acute pulmonary response and lung deposition of surfactant by LISA and InSurE in surfactant-depleted adult rabbits. Methods Twenty-six spontaneously breathing surfactant-depleted adult rabbits (6–7 weeks old) with moderate RDS and managed with nasal continuous positive airway pressure were randomized to 3 groups: (1) 200 mg/kg of surfactant by InSurE; (2) 200 mg/kg of surfactant by LISA; (3) no surfactant treatment (Control). Gas exchange and lung mechanics were monitored for 180 min. After that, surfactant lung deposition and distribution were evaluated monitoring disaturated-phosphatidylcholine (DSPC) and surfactant protein C (SP-C), respectively. Results No signs of recovery were found in the untreated animals. After InSurE, oxygenation improved more rapidly compared to LISA. However, at 180’ LISA and InSurE showed comparable outcomes in terms of gas exchange, ventilation parameters, and lung mechanics. Neither DSPC in the alveolar pool nor SP-C signal distributions in a frontal lung section were significantly different between InSurE and LISA groups. Conclusions In an acute setting, LISA demonstrated efficacy and surfactant lung delivery similar to that of InSurE in surfactant-depleted adult rabbits. Impact Although LISA technique is gaining popularity, there are still several questions to address. This is the first study comparing LISA and InSurE in terms of gas exchange, ventilation parameters, and lung mechanics as well as surfactant deposition and distribution. In our animal study, three hours post-treatment, LISA method seems to be as effective as InSurE and showed similar surfactant lung delivery. Our findings provide some clarifications on a fair comparison between LISA and InSurE techniques, particularly in terms of surfactant delivery. They should reassure some of the concerns raised by the clinical community on LISA adoption in neonatal units

Surfactant lung delivery with LISA and InSurE in adult rabbits with respiratory distress

Background: In preterm infants, InSurE (Intubation\u2013Surfactant\u2013Extubation) and LISA (less invasive surfactant administration) techniques allow for exogenous surfactant administration while reducing lung injury associated with mechanical ventilation. We compared the acute pulmonary response and lung deposition of surfactant by LISA and InSurE in surfactant-depleted adult rabbits. Methods: Twenty-six spontaneously breathing surfactant-depleted adult rabbits (6\u20137 weeks old) with moderate RDS and managed with nasal continuous positive airway pressure were randomized to 3 groups: (1) 200 mg/kg of surfactant by InSurE; (2) 200 mg/kg of surfactant by LISA; (3) no surfactant treatment (Control). Gas exchange and lung mechanics were monitored for 180 min. After that, surfactant lung deposition and distribution were evaluated monitoring disaturated-phosphatidylcholine (DSPC) and surfactant protein C (SP-C), respectively. Results: No signs of recovery were found in the untreated animals. After InSurE, oxygenation improved more rapidly compared to LISA. However, at 180\u2019 LISA and InSurE showed comparable outcomes in terms of gas exchange, ventilation parameters, and lung mechanics. Neither DSPC in the alveolar pool nor SP-C signal distributions in a frontal lung section were significantly different between InSurE and LISA groups. Conclusions: In an acute setting, LISA demonstrated efficacy and surfactant lung delivery similar to that of InSurE in surfactant-depleted adult rabbits. Impact: Although LISA technique is gaining popularity, there are still several questions to address. This is the first study comparing LISA and InSurE in terms of gas exchange, ventilation parameters, and lung mechanics as well as surfactant deposition and distribution.In our animal study, three hours post-treatment, LISA method seems to be as effective as InSurE and showed similar surfactant lung delivery.Our findings provide some clarifications on a fair comparison between LISA and InSurE techniques, particularly in terms of surfactant delivery. They should reassure some of the concerns raised by the clinical community on LISA adoption in neonatal units

Gli antiossidanti nella pratica erboristica

Il Corso di Laurea in Tecniche Erboristiche della Facolt\ue0 di Farmacia dell\u2019Universit\ue0 di Bologna propone periodicamente, nella sua sede di Imola, incontri di approfondimento aperti non solo agli studenti ed ai professionisti del settore, ma a chiunque sia interessato a conoscere impieghi e propriet\ue0 delle piante officinali. L\u2019argomento scelto in questa occasione, lo stress ossidativo, verr\ue0 sviluppato dai vari relatori sulla base di esperienze professionali diverse allo scopo di fornire un quadro quanto pi\uf9 aggiornato e completo circa propriet\ue0 e limiti dei prodotti comunemente proposti per contrastare tale processo

Innovative drug systems for delivery of drugs for which bioavailability is critical

Numerosi farmaci presentano solubilit\ue0, stabilit\ue0, permeabilit\ue0 che ostacolano lo sviluppo di una forma di somministrazione non parenterale. E' pressante pertanto la necessit\ue0 di prevedere nuove vie e strategie di somministrazione per superare tali problematiche senza ricorrere a modifiche chimiche di tali farmaci che originerebbero una sostanza completamente nuova. La tecnologia farmaceutica oltre a valutare vie di somministrazione alternative a quella parenterale \ue8 in grado di realizzare sistemi supramolecolari capaci di mascherare la struttura molecolare del farmaco aiutandolo a superare passaggi critici per la sua disponibilit\ue0 biologica. In particolare, le nano/microtecnologie farmaceutiche consentono la fabbricazione di particelle da usare come vettori che, per la loro struttura e composizione, possono modificare il destino del farmaco. Un\u2019ampia sezione della nostra ricerca \ue8 rivolta allo studio di sistemi farmaceutici (nano/microsfere, nano/microcapsule, micelle polimeriche e sistemi macromolecolari) per il rilascio di farmaci che presentano gravi difetti biofarmaceutici e farmacocinetici, che potrebbero essere risolti con la loro inclusione in vettori. In particolare, attualmente si stanno realizzando vettori a destabilizzazione sito-specifica per la veicolazione di farmaci a struttura peptidica, costituiti da materiali biocompatibili e/o biodegradabili in grado di promuovere un rilascio selettivo del farmaco nell\u2019ambiente caratteristico del sito di trattamento o di assorbimento

Preparazioni erboristiche e fitocosmetiche. Aspetti formulativi e metodologie produttive.

Le piante rappresentano una fonte preziosa per la produzione di prodotti con finalit\ue0 salutistiche, nutrizionali e cosmetiche. Ci\uf2 avviene in armonia con l\u2019evoluzione del concetto di salute, un tempo inteso unicamente come assenza di malattia, oggi sempre pi\uf9 associato alla ricerca di completo benessere fisico e mentale. In questa prospettiva l\u2019utilizzo del substrato vegetale rappresenta un riferimento importante in tutti gli approcci rivolti alla prevenzione delle malattie, al mantenimento dello stato di benessere psico-fisico, al potenziamento delle difese dell\u2019organismo ed al miglioramento del proprio aspetto. Il processo produttivo, che partendo dal substrato vegetale permette di ottenere il prodotto finito, prevede la definizione di un\u2019opportuna forma di dosaggio in grado di garantire la cessione delle sostanze funzionali nel modo pi\uf9 appropriato. In ambito erboristico, questo processo di produzione del prodotto finito fa riferimento, fondamentalmente, a tecnologie analoghe a quelle utilizzate nel settore farmaceutico, riproponendone anche gli aspetti pi\uf9 innovativi, quali la preparazione di sistemi particellari (micro/nanosfere, micro/nanocapsule, liposomi ecc.). Come esempio degli aspetti preparativi e delle prospettive d\u2019impiego dei sistemi particellari, in ambito erboristico e fitocosmetico, descriviamo la realizzazione di microcapsule contenenti oli essenziali. Ricordiamo che le microcapsule sono strutture formate da un nucleo centrale, contenente la sostanza funzionale in forma liquida o solida, circondato da una membrana polimerica. Questi sistemi si differenziano dalle microsfere che sono costituite da una matrice polimerica o lipidica solida, contenente la sostanza attiva disciolta o finemente dispersa. Entrambe queste formulazioni possono essere utilizzate in campo erboristico non solo per migliorare la stabilit\ue0, la sicurezza d\u2019impiego e le caratteristiche organolettiche delle sostanze incapsulate, ma anche per aumentarne la biodisponibilit\ue0 ed eventualmente garantirne un rilascio modificato. I sistemi microparticellari rispondono quindi adeguatamente alla necessit\ue0 di superare alcuni inconvenienti legati all\u2019utilizzo delle sostanze vegetali che sono spesso caratterizzate da scarsa solubilit\ue0, difficile assorbimento, instabilit\ue0 chimica, sapore ed odore sgradevoli. Le preparazioni che riportiamo hanno come obiettivo l\u2019incapsulamento, mediante spray-drying, di una frazione lipofila, generalmente un olio essenziale, all\u2019interno di una struttura di contenimento idrofila, quale un polimero di origine naturale o sintetica. Gli oli che sono stati presi in considerazione sono l\u2019olio di Neem e l\u2019olio di mirto australiano, utilizzando come materiali di rivestimento l\u2019alcool polivinilico e la pectina associati alla gomma arabica. L\u2019olio di Neem \ue8 stato cos\uec migliorato nelle sue caratteristiche organolettiche e protetto da fenomeni di degradazione ambientale; mentre le microcapsule di olio di mirto sono state proposte per potenziare le propriet\ue0 antimicrobiche dell\u2019olio nell\u2019ambito di una formulazione fitocosmetica

New environmental sensitive system for colon-specific delivery of peptidic drugs.

Colon specific drug delivery systems have gained increased importance for systemic and local delivery of protein and peptide drugs. Vancomycin, a peptidic drug, in the treatment of pseudomembranous colitis must be given orally to reach the site of infection. To achieve successful colonic delivery, vancomycin needs to be protected from degradation in the environment of the upper gastrointestinal tract and then be abruptly released into the colon. This work describes the use of thermally crosslinked bovine serum albumin (BSA) nanospheres (NS) coated with different fatty acids as carriers able to control the release of vancomycin (Vanco) in the colon environment responding strongly to stimuli such as pH, mucin interactions and enzyme digestion

Omega-3 fatty acid and antioxidant enriched liposomes for nasal administration of anti-Alzheimer drugs

The purpose of this work was the formulation of liposomes for nasal administration of tacrine\ub7HCl. This route has many advantages, in fact it is possible to convey the drug directly to the CNS, through the olfactory bulb. Part of tacrine administered can also be absorbed into the systemic circulation avoiding hepatic first pass effect. Liposomes were formulated with ingredients that have a beneficial effect against the disease. In particular, the cholesterol was replaced with α-tocopherol, and phospholipids were enriched with polyunsaturated fatty acids (DHA, EPA α-linolenic acid). This formulative approach allowed us to obtain 100% active liposomes against symptoms of Alzheimer's disease

Fatty acid substituted polyvinyl alcohol as a supporting material for microsphere preparation

Polyvinyl alcohol, substituted with lauric, myristic, palmitic, and stearic acids at different substitution degrees was employed for the preparation of biodegradable microspheres containing progesterone or indomethacin. A solvent extraction/method was followed, starting from an oil-in-water dispersion containing the polymer and drug in the inner phase. Microspheres were obtained with high loading efficiency, whose release properties were dependent on the nature of the acyl substituent and the substitution degree. Kinetics approaching zero-order were obtained for the most hydrophile microspheres such as those based on the least substituted polymers and lowest molecular weight substituents. The hydrophilicity of these systems hindered protein absorption on their surface, suggesting their suitability for parenteral use