Ionic liquid proteins: a route towards room temperature stable antibodies and vaccines

每年有1亿多婴儿接种疫苗，每年挽救300万人的生命。全球卫生界已经认识到疫苗在预防疾病方面的重要性，并致力于在全球提供疫苗。美国疾病控制和预防中心（CDC）建议，除了口服脊髓灰质炎疫苗外，大多数疫苗应储存在2至8摄氏度之间，以保持疫苗效力。但是，如果储存温度低于推荐温度范围，则意外冻结疫苗可能导致团聚，从而降低疫苗的效力。冷链的做法往往会忽视疫苗的意外冷冻，因为在较高的温度下会产生相关的热损伤。尽管如此，儿童基金会2005年用于所有疫苗的4.39亿美元中，有31%以上用于冷冻敏感疫苗。因此，向电力和冷库有限的第三世界国家分发疫苗给本已脆弱的“冷链”带来了额外的压力。治疗性蛋白质储存的一种建议解决方案是使用离子液体（ILs）增加蛋白质和抗体的热稳定性，避免在运输和储存期间对疫苗进行冷藏。离子液体由于其独特和可调的性质，已被广泛应用于材料科学、催化和药物化学等领域。离子液体具有很高的热稳定性、化学稳定性和电化学稳定性。此外，人们对离子液体的兴趣主要是由于它们的蒸气压可以忽略不计，因此有可能成为一种“绿色溶剂”来取代挥发性有机溶剂。尽管有这些优点，蛋白质在无水条件下往往高度不稳定，在离子液体中难溶。本研究建议使用抗体和病毒的表面修饰来增加它们在离子液体中的溶解度，增加蛋白质的热稳定性，同时保留它们的蛋白质生物学功能。

Vaccines are administered to more than 100 million infants a year, saving three million lives annually. The global health community has recognised the importance of vaccines in the prevention of diseases and are committed to making vaccines available globally. The Centres for Disease Control and Prevention (CDC) recommends that most vaccines should be stored between 2 and 8 Degrees Centigrade, except the oral polio vaccine, to maintain the vaccine efficacy. However, if the storage temperature is lower than the recommended temperature range, then accidental freezing of vaccines can lead to agglomeration, which can reduce the potency of vaccine. Cold chain practices tend to overlook accidental freezing of vaccines because of the associated heat damage at higher temperatures. Despite this, over 31 % of the US$ 439 million UNICEF spent on all vaccines in 2005 are spent on freeze-sensitive vaccines. Therefore, the distribution of vaccines to third-world countries, where electricity and cold storage are limited, puts additional stress on the already fragile 'cold chain'. A proposed solution to the storage of therapeutic proteins is to increase the thermal stability of proteins and antibodies using ionic liquids (ILs), avoiding the need for refrigeration of vaccines during shipping and storage. The use of ionic liquids have become increasingly popular and have been used for various applications such as material science, catalysis and medicinal chemistry due to their unique and tuneable properties. Ionic liquids have high thermal, chemical and electrochemical stabilities. In addition, most of the interest in ionic liquids is due to their negligible vapour pressures and therefore the possibility of a 'green solvent' to replace volatile organic solvents. Despite these advantages, proteins tend to be highly unstable in anhydrous conditions and poorly soluble in ionic liquids. This study proposes using surface modification of antibodies and viruses to increase their solubility in ionic liquids increasing protein thermal stability whilst retaining their protein biological function.