It was another incredible Canadian Chemical Engineering Conference (CCEC) for ChemE students. During the 2021 virtual conference in October, Mickael Dang (PhD Candidate) placed first in the Reg Friesen Student Oral Paper Competition, Erin Ng (ChemE 2T3) placed third in the Robert G. Auld Student Paper Competition, and Arianna Skirzynska (PhD Candidate) placed second in the 3-Minute Pitch Competition.
Mickael’s winning presentation entitled, Towards A Stable Hyaluronan-Based Hydrogel as A Biomimetic Vitreous Substitute highlights a promising next generation vitreous substitite for the surgical management of retinal detachment (RD). RD, a separation of the neurosensory retina from the underlying retinal pigment epithelium, is a sight-threatening emergency and the fifth leading cause of blindness in developing countries. Following RD, the retina is detached from the posterior segment of the eye, causing permanent vision loss if left untreated. The current gold-standard for the management of RD employs a vitreous substitute to replace the native vitreous body following vitrectomy surgery, thereby repositioning the retina to its original location. However, most common substitutes, namely expansile gases and silicone oils, can be troublesome for patients due to weeks of blurred vision plus face-down positioning and secondary surgery for oil removal, respectively. Mickael and team developed a novel vitreous substitute composed of hyaluronan, a natural component of the vitreous, crosslinked with poly (ethylene glycol) using oxime chemistry. Their newly designed vitreous substitute comprises similar physical properties to the native vitreous, including refractive index, density and transparency. Additionally, it is both cytocompatible with photoreceptors from mouse retinal explants and biocompatible when injected into eyes of rabbits. The physiological ocular pressure in rabbit eyes was maintained for at least 56 days and the retina, demonstrating the minimally swelling characteristic of their material. Function of the retina was also confirmed by electroretinography up to 90 days. Their vitreous substitute was stable in vivo over 28 days, after which degradation began with approximately 50% loss by day-56.
Erin’s winning paper entitled, Development of Liposomes for the Encapsulation of Iron to Fortify Hibiscus Sabdariffa Calyces Beverage addresses dietary iron deficiency (ID) which accounts for 50% of the global anemia body. ID is prevalent in low-and middle-income countries, impacting the health of their populations and stunting socio-economic development. Recently, Hibiscus sabdariffa calyces beverage is being considered as a food vehicle for iron fortification in Sub-Saharan Africa, where it is regularly consumed. However, the beverage contains polyphenols, which inhibit iron absorption by forming complexes with iron. This study aims to adopt liposomal encapsulation technology to prevent added iron from interacting with polyphenols in the beverage. Preliminary experiments focused on material selection to develop stable liposomes. Two soy lecithin sources, Acros (granular) and ADM (liquid), and their solubilities in 95% and absolute ethanol were compared. Next, the molar ratio of lecithin to cholesterol, a membrane stabilizer, was varied: 1:0, 1:.25, 1:.5, and 1:1. Liposomes were prepared via thin film hydration. Ethanol was removed using a rotary evaporator, the resulting thin films were rehydrated with Milli-Q water or iron sulfate solution (11.3ppm) and the particle sizes were reduced via ultrasonication. The liposomal suspension was separated using an ultracentrifuge. Morphological and encapsulation efficiency analyses were performed to determine the feasibility of fortifying Hibiscus beverage with the formulated liposomes.
Arianna’s winning pitch entitled, Towards Personalized Glioblastoma Therapies with 3D Hydrogel Models outlines treatment for aggressive brain tumours. Modern cancer therapy development is confounded by the massive genetic heterogeneity which exists between patients. This is especially prominent in Glioblastoma (GBM), an aggressive primary brain tumour, which contains a subpopulation of highly invasive chemo- and radiotherapy-resistant cancer stem-like cells, termed glioma neural stem cells (GNSCs). To capture patient-specific GNSC behaviour, a tumour-mimetic hydrogel has been developed using upregulated extracellular matrix components known to exist in the native tumour microenvironment. Subtype-dependent invasion profiles are observed which correlate to patient prognosis and allow mechanisms of invasion and tumour progression to be probed. When an invasion-related gene is targeted, a quantifiable change in phenotypic invasion will illustrate patient-specific response to therapeutics, showing this platform’s promise to enhance the drug development pipeline for new GBM therapeutics.
Both Mickael and Arianna are supervised by Prof. Molly Shoichet, and Erin supervised by Prof. Levente Diosady. A big congratulations to our students and their supervisors!