The potential to replace shark-derived squalene in vaccine adjuvant applications with synthetic squalene/poly(isoprene) oligomers, synthesized by the controlled oligomerization of isoprene is demonstrated. Following on from our previous work regarding the synthesis of poly(isoprene) oligomers, we demonstrate the ability to tune the molecular weight of the synthetic poly(isoprene) material beyond that of natural squalene, while retaining a final backbone structure that contained a minimum of 75% of 1,4 addition product and an acceptable polydispersity. The synthesis was successfully scaled from the 2 g to the 40 g scale both in the bulk (i.e., solvent free) and with the aid of additional solvent by utilizing catalytic chain transfer polymerization (CCTP) as the control method, such that the target molecular weight, acceptable dispersity levels, and the desired level of 1,4 addition in the backbone structure and an acceptable yield (∼60%) are achieved. Moreover, the stability and in vitro bioactivity of nanoemulsion adjuvant formulations manufactured with the synthetic poly(isoprene) material are evaluated in comparison to emulsions made with shark-derived squalene. Emulsions containing the synthetic poly(isoprene) achieved smaller particle size and equivalent or enhanced bioactivity (stimulation of cytokine production in human whole blood) compared to corresponding shark squalene emulsions. However, as opposed to the shark squalene-based emulsions, the poly(isoprene) emulsions demonstrated reduced long-term size stability and induced hemolysis at high concentrations. Finally, we demonstrate that the synthetic oligomeric poly(isoprene) material could successfully be hydrogenated such that >95% of the double bonds were successfully removed to give a representative poly(isoprene)-derived squalane mimic.
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http://dx.doi.org/10.1021/acs.biomac.5b01285 | DOI Listing |
Microorganisms
October 2024
Center for Biotechnology of Natural Resources (CENBio), Catholic University of Maule, Avda. San Miguel 3605, Talca 3460000, Chile.
Plastics are very versatile materials that have contributed to the development of society since the 19th century; however, their mismanagement has led to an accumulation of plastic waste in almost every ecosystem, affecting the fauna of the planet. However, recently, some studies have shown that some insects might be able to adapt, consuming a wide range of hydrocarbon base polymers. In this work, the adaptive capacity of larvae when feeding on different synthetic polymers derived from petroleum was studied.
View Article and Find Full Text PDFJ Am Soc Mass Spectrom
December 2024
Department of Chemistry, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland.
Aliphatic hydrocarbons and hydrocarbon-based synthetic polymers are of interest in many fields, but their characterization by mass spectrometric methods is generally limited due to their poor ionizability. Recently, atmospheric pressure photoionization (APPI), combined with halogen anion attachment in negative-ion mode, has drawn attention as a potential method for ionizing various polymers without extensive fragmentation or other unwanted side reactions. In this work, the applicability of halogen anion attachment with APPI was studied using several synthetic polymers, including polyethylene, polypropylene, polyisoprene, and polystyrene, as well as simple -alkanes of various chain lengths.
View Article and Find Full Text PDFPolymers (Basel)
September 2024
Shandong Provincial College Laboratory of Rubber Material and Engineering/Key Laboratory of Rubber-Plastics, Ministry of Education, School of Polymer Science and Engineering, Qingdao University of Science & Technology, Qingdao 266042, China.
The Nd-mediated coordinative chain transfer polymerization (CCTP) of dienes represents one of the state-of-the-art techniques in the current synthetic rubber field. Besides having well-controlled polymerization behaviors as well as high atom economies, it also allows for the generation of highly reactive Al-capped polydienyl chain-ends, which hold great potential, yet much less explored up to date, in achieving end functionalization to mimic the structure of natural rubber. In this study, we demonstrate an efficient in situ method to realize end-functionalizing polyisoprene by introducing epoxide compounds into a CCTP system.
View Article and Find Full Text PDFACS Polym Au
August 2024
Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.
This study elucidates the pivotal role of terminal structures in -1,4-polyisoprene (PI) chains, contributing to the exceptional mechanical properties of Hevea natural rubber (NR). NR's unique networking structure, crucial for crack resistance, elasticity, and strain-induced crystallization, involves two terminal groups, ω and α. The proposed ω terminal structure is dimethyl allyl-(-1,4-isoprene), and α terminals exist in various forms, including hydroxy, ester, and phosphate groups.
View Article and Find Full Text PDFPatient Saf Surg
May 2024
Department of Food, Agricultural, and Biological Engineering, The Ohio State University, 590 Woody Hayes Drive, Columbus, OH, 43210, USA.
Background: Medical professionals are constantly exposed to bodily fluids and sanitizing agents during routine medical procedures. Unbeknownst to many healthcare workers, however, the barrier integrity of medical gloves can be altered when exposed to these substances, potentially resulting in exposure to dangerous pathogens.
Methods: This experimental study was designed to test the hypothesis that the durability of both natural and synthetic solvent-exposed medical gloves will be lower than the durability of the gloves in air.
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