Production and Properties of Yulex® - The Natural Solution to Latex Allergy

Abstract

Natural rubber is an irreplaceable raw material vital to industry, transportation, medicine and defense, largely produced from clonal plantations of Hevea brasiliensis in Southeast Asia. Additional rubber-producing crops are greatly desired to increase biodiversity, protect supplies, and provide a safe alternative for people suffering from Type I latex protein allergy. Basic and applied research approaches were used to make the production of latex (Yulex® latex) from Parthenium argentatum (guayule) a commercial reality. In contrast to Hevea brasiliensis, from which rubber latex is tapped by hand from laticifers, guayule latex rubber is contained within individual bark parenchyma cells. Processing involves disrupting these cells to release the rubber particles, and then purifying the latex. As in the Hevea industry, latex concentration can be achieved by centrifugation and/or by creaming agents. An artificially produced guayule natural rubber latex is then produced, under the material name of “Yulex® latex”. The Yulex Pilot Plant has been constructed, optimized and automated, and extracts then purifies latex from guayule shrub without detectable losses. The natural rubber polymers in guayule latex are high molecular weight and products made from this material have the desired high performance properties. Because guayule latex contains very little protein, all of which is hydrophobic and bound to the rubber phase, and because none of the protein cross-reacts with Type I latex allergy to Hevea latex products, its use is initially aimed towards the high-value medical products marketplace. Clinical and performance trials continue to ensure that guayule processing provides a safe, high performance, non-allergenic natural rubber latex that is safe for human use.

Protein influences on guayule and Hevea natural rubber sol and gel

“…However, upon storage, changes in rubber particle‐bound proteins, including protein hydrolysis into more serum‐soluble form, can occur. It should be noted that while high in this series, 507 µg/g is significantly lower than other reports for Hevea latex using the same method . Based on the total protein detected in the HA‐G materials, the fractionation process used can be considered at least 97% effective for protein removal.…”

“…Natural rubber from guayule is stored in bark parenchyma cells, unlike the laticifers of Hevea brasiliensis , so instead of tapping to extract rubber, guayule shrubs are ground in the presence of an aqueous buffer or organic solvent . Consequently, the non‐rubber constituents present in the latex or rubber, and carried into compounding processes, differ significantly with corresponding impacts on physical and chemical properties . For example, guayule latex has been shown to be free of Type I latex allergens and, therefore, can be used to produce products safe for people who suffer from Type I latex allergy …”

Transcriptome and gene expression analysis in cold-acclimated guayule (Parthenium argentatum) rubber-producing tissue

“…Mature guayule plants produce high quality natural rubber in bark parenchyma tissue, mainly during winter when night temperatures are moderately cold, between 6 and 15°C (Bonner, 1943;Downes and Tonnet, 1985;Madhavan et al, 1989;Sundar and Reddy, 2000;Veatch-Bolhm et al, 2007;Benedict et al, 2010). The high quality of guayule rubber makes it amenable for industrial applications and is comparable to that produced by the rubber tree, Hevea brasiliensis (Cornish et al, 2008). As extracted, guayule latex also has the added benefit of lacking allergens in significant amounts to trigger Type I systemic allergies in humans (Hamilton and Cornish, 2010;Siler et al, 1996;Siler and Cornish, 1994a).…”

Do single-use medical devices containing biopolymers reduce the environmental impacts of surgical procedures compared with their plastic equivalents?

“…One factor that has contributed to these opportunities is that newly developed biopolymers are able to retain similar physical characteristics of synthetic plastics. For example, emerging studies show that guayule-derived latex rubber is a suitable substitute for flexible plastics and traditional rubber products (Cornish, Williams, Hall, & III, 2008;Rasutis, Soratana, McMahan, & Landis, 2015). Another study shows that the biopolymer polylactide (PLA) is a suitable substitute for different forms of plastic (Madhavan Nampoothiri, Nair, & John, 2010).…”