Development and in vitro characterization of chitosan-coated polymeric nanoparticles for oral delivery and sustained release of the immunosuppressant drug mycophenolate mofetil

Objective: To develop an oral sustained release formulation of mycophenolate mofetil (MMF) for once-daily dosing, using chitosan-coated polylactic acid (PLA) or poly(lactic-co-glycolic) acid (PLGA) nanoparticles. The role of polymer molecular weight (MW) and drug to polymer ratio in encapsulation efficiency (EE) and release from the nanoparticles was explored in vitro.

Methods: Nanoparticles were prepared by a single emulsion solvent evaporation method where MMF was encapsulated with PLGA or PLA at various polymer MW and drug: polymer ratios. Subsequently, chitosan was added to create coated cationic particles, also at several chitosan MW grades and drug: polymer ratios. All the formulations were evaluated for mean diameter and polydispersity, EE as well as in vitro drug release. Differential scanning calorimetry (DSC), surface morphology, and in vitro mucin binding of the nanoparticles were performed for further characterization.

Results: Two lead formulations comprise MMF: high MW, PLA: medium MW chitosan 1:7:7 (w/w/w), and MMF: high MW, PLGA: high MW chitosan 1:7:7 (w/w/w), which had high EE (94.34% and 75.44%, respectively) and sustained drug release over 12?h with a minimal burst phase. DSC experiments revealed an amorphous form of MMF in the nanoparticle formulations. The surface morphology of the MMF NP showed spherical nanoparticles with minimal visible porosity. The potential for mucoadhesiveness was assessed by changes in zeta potential after incubation of the nanoparticles in mucin.

Conclusion: Two chitosan-coated nanoparticles formulations of MMF had high EE and a desirable sustained drug release profile in the effort to design a once-daily dosage form for MMF.     

Tropane alkaloid contamination of agricultural commodities and food products in relation to consumer health: Learnings from the 2019 Uganda food aid outbreak

Tropane alkaloids (TAs) are secondary plant metabolites derived mainly from Solanaceae plant families, with the most virulent invasive species being Datura stramonium. Datura stramonium commonly grows in cereal fields and produce TAs (e.g., hyoscyamine and scopolamine) which may accidentally contaminate cereals (and cereal-based foods) at occasionally high levels. Dietary exposure to TAs can be toxic and depending on the dose ingested can cause outcomes ranging from anticholinergic effects to acute poisoning and death. In 2019, 315 adults became ill and another five adults died in Uganda following consumption of a “Super Cereal” (a fortified blended food) that was later confirmed to be contaminated by TAs—a scenario which provoked this holistic review on TAs in foodstuffs. Thus, this article provides information on the history, development, occurrences, exposures, and human legislative and health benchmarks for TAs. It describes control strategies for reducing TA contamination of agricultural commodities and resultant health implications following consumption of TA contaminated foodstuffs. Adequate application of food safety control measures (including maximum limits) and good practices, from the start of cereal cultivation through to the final stages of manufacturing of food products can aid in the reduction of seeing toxic plants including D. stramonium in cereal fields.     

Generating value across academic and professional design practice in the Internet of Things

ABSTRACT

This article accounts for how value in design research can be derived from knowledge exchange that occurs through the collaborative discourse of doing design. To demonstrate this point, the article details the arc and impact of a design research collaboration that extended over several years with design practitioners in the field of internet-connected devices. As a result of this ongoing collaborative work, a programmatic set of design ideals and intentions concerning how to construct a more transparent and ethical relationship with technology was shaped. We examine this sustained and transformative collaboration as a series of knowledge exchanges. Within each particular collaborative project, worldviews and knowledge are exchanged among design researchers and practitioners, enabling them to traverse ‘through practices’ of academic and professional design. To unpack these exchanges and how they built and fed into each other, the article examines how collaboration unfolded and produced value on two levels: first on the scale of the academics and practitioners directly involved in a project; and secondly on the scale of the larger international community of design practitioners concerned with Internet-connected devices, with whom we had shared our work.     

The effect of age,gender and attitudes on self-regulation in driving

Self-regulation in driving has primarily been studied as a precursor to driving cessation in older people, who minimise driving risk and compensate for physical and cognitive decline by avoiding driving in challenging circumstances, e.g. poor weather conditions, in the dark and at busy times. This research explores whether other demographic groups of drivers adopt self-regulatory behaviours and examines the effects of affective and instrumental attitudes on self-regulation across the lifespan. Quantitative data were collected from 395 drivers. Women were significantly more likely than men to engage in self-regulation, and to be negatively influenced by their emotions (affective attitude). A quadratic effect of age on self-regulation was determined such that younger and older drivers reported higher scores for self-regulation than middle-years’ drivers. However, this effect was affected by experience such that when experience was controlled for, self-regulation increased with age. Nevertheless, anxious driving style and negative affective attitude were independent predictors of self-regulation behaviours. Results suggest that self-regulation behaviours are present across the driving lifespan and may occur as a result of driving anxiety or low confidence rather than as an effect of ageing.     

Inverting an image does not improve drawing accuracy.

It has been suggested that inverting an image will increase drawing accuracy. However, perceptual evidence suggests that inverting an image inhibits processing of spatial information. D. J. Cohen and S. Bennett (1997) theorized that perceptual distortions will lead to drawing errors. In the present experiment, the authors test whether inverting an image improves drawing accuracy, as suggested by art educators, or results in distorted drawings, as predicted by Cohen and Bennett. The present data reveal that inverting an image inhibits the drawing accuracy of spatial relations thus supporting Cohen and Bennett's (1997) theory of drawing accuracy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structure–property quantification of corrosion pitting under immersion and salt-spray environments on an extruded AZ61 magnesium alloy

Extruded AZ61 magnesium coupons were exposed to immersion and cyclical salt spray environments over 60 h in order to characterize their corrosion rates. The characteristics of general corrosion, pitting corrosion, and intergranular corrosion were quantified at various intervals. General corrosion was more prevalent on the immersion surface. In addition, more pits formed on the immersion surface due the continuous exposure to water and chloride ions. However, the pits on the salt spray surface showed larger surface areas, larger volumes, and covered more area on the micrographs as compared to the pits on the immersion surface, due to the dried pit debris that trapped chloride ions within the pits.     

Underdiagnosing and nontreatment of posttraumatic stress disorder in community mental health: A case study.

Research indicates that trauma is extremely prevalent among populations seeking community-based services. However, underdiagnosis and nontreatment of trauma-related disorders is widespread. This study explored how one urban community mental health center (CMHC), serving a severely mentally ill (SMI) population, assessed, diagnosed, and treated reported trauma histories. Results indicate that of the 72 consumers in this sample who reported trauma histories (51%), only 2 were diagnosed with posttraumatic stress disorder (PTSD). Instead, those with a reported trauma history were likely to be diagnosed with affective disorders and were almost seven times as likely to be recommended therapy as were those without a trauma history. However, even those recommended therapy were not likely to receive it. Findings indicate significant barriers to PTSD diagnoses and the receipt of therapy services. (PsycINFO Database Record (c) 2010 APA, all rights reserved)