Team:Lethbridge/Description

Project Description

Diabetes, a disease caused by abnormal insulin regulation and production in the pancreas, affects approximately 8.8% of the global population. Diabetes requires lifelong management and thus imposes an enormous economic health burden, amounting to a $673 billion global expenditure annually (Ogurtsova et al., 2017). Currently, the most common method of relieving diabetes symptoms is the subcutaneous injection of recombinant insulin (produced in microbes) to self-regulate blood sugar levels. Patients who depend on prescribed insulin must self-administer the drug up to six times per day, which can cause soreness and anxiety, especially in children (American Diabetes Association, 2007).

From our preliminary interviewswith diabetic patients, diabetes researchers, and medical professionals, it was clear that insulin and administration supplies are unaffordable (even with insurance coverage), injections and insulin pumps are painful and inconvenient, and that all patients would choose an oral alternative if it were available.

Currently, the primary challenge with the oral administration of insulin is that it is degraded or denatured by the acids and enzymes of the stomach before it can be absorbed in the intestines (Arbit & Kidron, 2009). Novo Nordisk produced an oral insulin that reached Phase II clinical trials but abruptly halted development because the oral dosage required was 58 times that of the subcutaneous dosage and was not deemed a cost-effective alternative (Halberg et al., 2019). Thus, there remains an unmet demandfor low-cost methods of manufacturing oral insulin and/or novel methods for delivering insulin directly to the intestine.

Thus, we developed a novel method for the manufacturing and oral delivery of insulin within microalgae: “Algulin”. Algulin is a recombinant microalgae strain derived from acidophilic Cyanidioschyzon merolae and designed to produce either the ultrastable oral insulin analog, SCI-57 (Hua et al., 2008), or proinsulin peptides (Boyhan & Daniell, 2011) within its chloroplasts. The C. merolae cell wall is resistant to degradation in acidic environments (like that of the stomach) and thus acts as a protective capsule. The cell wall is subsequently digested by bacteria in the intestines to release the insulin (Kwon & Daniell, 2016). The specifics of our genetic modifications, including a cell-penetrating peptide to improve delivery of the insulin to cells in the gut lumen and internal furin cleavage sites to ensure appropriate post-translational processing of proinsulin peptides outside the pancreas, can be found on our Design page.

Furthermore, microalgae-derived pharmaceuticals can be considered “value-added products” because of the many additional health benefits of consuming algae (Kothari et al., 2017). Various algae biomass-based supplements and algal-derived proteins have already been approved for human consumption by Health Canada and the United States Food & Drug Administration (Health Canada, 2019; Garcia et al., 2017). Thus, the microalgae itself can be consumed without the need for complicated insulin protein extraction and purification procedures (thereby decreasing the cost of manufacturing) and eliminating uncomfortable subcutaneous injections. Furthermore, compared to bioencapsulation in plant chloroplasts (Kwon & Daniell, 2016) or the production of biosimilar insulins(Gotham et al., 2018), manufacturing in microalgae is predicted to be more cost-effective.

In addition, we implemented a built-in fluorescent control to quantify insulin expression levels and standardize the ratio of insulin to microalgae mass, a custom photobioreactor(with fluorometer) prototype, as well as associated photobioreactor software to further simplify manufacturing.

Significance

Altogether, Algulin is anticipated to have greater efficacy than previously tested oral insulins, be more cost-effective than current insulin production methods, improve access for low-income patients or nations, and would eliminate uncomfortable injections for many diabetic patients if commercialized.

References

American Diabetes Association. (2007). Insulin Administration. Diabetes Care, 26, 121-124.

Arbit E., & Kidron M. (2009). Oral insulin: the rationale for this approach and current developments. Journal of Diabetes Science and Technology, 3(3), 562–567.

Boyhan D., & Daniell H. (2011). Low-cost production of insulin in tobacco and lettuce chloroplasts for injectable or oral delivery of functional insulin and C-peptide. Plant Biotechnol J, 9(5), 585-598.

Garcia J. L., de Vicente M., & Galán B. (2017). Microalgae, old sustainable good and fashion nutraceuticals. Microb Biotechnol, 10(5), 1017-1024.

Gotham, D., Barber, M. J., & Hill, A. (2018). Production costs and potential prices for biosimilars of human insulin and insulin analogues. BMJ Global Health, 3, e000850.

Halberg I. B., Lyby K., Wassermann K., Heise T., Zijlstra E., & Plum-Mörschel L. (2019). Efficacy and safety of oral basal insulin versus subcutaneous insulin glargine in type 2 diabetes: a randomised, double-blind, phase 2 trial. Diabetes and Endrocrinology, 7, 179-188.

Health Canada. (2019). Approved Products. Accessed on March 4, 2019 at: https://www.canada.ca/en/health-canada/services/food-nutrition/genetically-modified-foods-other-novel-foods/approved-products.html

Hua Q.-X., Nakagawa S. H., Jia W., Huang K., Phillips N. B., Hu S.-Q., & Weiss M. A. (2008). Design of an active ultrastable single-chain insulin analog: synthesis, structure, and therapeutic implications. J Biol Chem, 283(21), 14703-14716.

Kothari, R., Pandey, A., Ahmad, S., Kumar, A., Pathak, V. V., & Tyagi, V. V. (2017). Microalgal cultivation for value-added products: a critical enviro-economical assessment. 3 Biotech, 7(4), 243.

Kwon K.-C., & Daniell H. (2016). Oral delivery of protein drugs bioencapsulated in plant cells. Molecular Therapy, 24(8), 1342-1350.

Ogurtsova K., Fernandes J. R., Huang Y., Linnenkamp U., Guariguate L., Cho N. H., Cavan D., Shaw J. E., & Makaroff L. E. (2017). IDF Diabetes Atlas: Global estimates for the prevalence of diabetes for 2015 and 2040. Diabetes Research and Clinical Practice, 128, 40-50.