Abstract Hyaluronic acid (HA), or hyaluronan, is a natural polyelectrolyte, ubiquitous in human tissues. Exogenous HA has been a valuable material due to its wide range of medical applications, such as in osteoarthritis treatment, ophthalmic surgery, adhesion prevention after surgeries and wound healing, as well as cosmetic applications. However, to ensure the physicochemical and biological properties, a purity near to 99% is a primary requirement, aiming clinical applications. To achieve this goal, various downstream operations have been used, aiming HA concentration, separation and purification. Precipitation with organic solvents has been a common operation in most purification processes, combined with other downstream operations such as precipitation with quaternary salts, filtration, adsorption and ion exchange. This work presents an updated review of HA purification, emphasizing the performance of the main downstream operations used to achieve highly purified HA, in the period from 1970 to 2019. We conclude that, in the majority of the published works, there is a lack of studies regarding the operational conditions, as well as an absence of the purification percentage development during the processes.

中文翻译：

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透明质酸纯化主要下游操作的表现

摘要 透明质酸 (HA) 或透明质酸是一种天然聚电解质，广泛存在于人体组织中。外源性透明质酸因其广泛的医学应用而成为一种有价值的材料，例如在骨关节炎治疗、眼科手术、手术和伤口愈合后的粘连预防以及美容应用中。然而，为了保证理化和生物学特性，接近99%的纯度是主要要求，针对临床应用。为了实现这一目标，已经使用了各种下游操作，旨在对 HA 进行浓缩、分离和纯化。有机溶剂沉淀是大多数纯化过程中的常见操作，与其他下游操作相结合，如季盐沉淀、过滤、吸附和离子交换。