Although in recent years several methods have been studied and developed to obtain different types of nanosized drug delivery systems, the set up of suitable procedures and materials remains highly expensive, their preparation is time consuming and often not feasible for a scale-up process. Furthermore, the sterilisation and storage of nanocarrier formulations represents a complicated but mandatory step for their effective use. In our previous work we assessed the use of an autoclaving process to achieve, in one simple step, sterile self-assembled hyaluronan-cholesterol (HA-CH) and hyaluronan-riboflavin (HA-Rfv) nanohydrogels (NHs). In the present work, the effect of the high temperature on HA-CH has been studied in detail. HA-CH suspensions were characterised in terms of size and polydispersity by Dynamic Light Scattering at different temperatures and conditions; the HA-CH chemical structure and its molecular weight were assessed via FT-IR and GPC analysis after the sterilising cycle in an autoclave at 121°C for 20min. The obtained NHs were then observed with TEM and AFM microscopy, in both dry and liquid conditions. The Young's modulus of the NHs was determined, evidencing the soft nature of these nanosystems; the critical aggregation concentration (c.a.c) of the nanosuspension was also assessed. Thereafter, alginate lyase (AL) was conjugated to NHs, with the aim of developing a useful system for therapies against bacterial infections producing alginate biofilms. The conjugation efficiency and the enzymatic activity of AL were determined after immobilisation. The AL-NHs system showed the ability to depolymerise alginate, offering an opportunity to be a useful nanosystem for the treatment of biofilm-associated infections.

中文翻译：

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透明质酸-胆固醇纳米水凝胶：携带海藻酸裂解酶的特性和有效性

尽管近年来已经研究和开发了几种方法来获得不同类型的纳米药物递送系统，但合适的程序和材料的设置仍然非常昂贵，它们的制备非常耗时并且通常不适用于放大过程。此外，纳米载体制剂的灭菌和储存代表了其有效使用的复杂但强制性的步骤。在我们之前的工作中，我们评估了使用高压灭菌过程以一个简单的步骤实现无菌自组装透明质酸胆固醇 (HA-CH) 和透明质酸核黄素 (HA-Rfv) 纳米水凝胶 (NHs)。在目前的工作中，已经详细研究了高温对 HA-CH 的影响。HA-CH 悬浮液在不同温度和条件下通过动态光散射在尺寸和多分散性方面进行表征；在 121°C 高压灭菌器中灭菌 20 分钟后，通过 FT-IR 和 GPC 分析评估 HA-CH 化学结构及其分子量。然后在干燥和液体条件下用 TEM 和 AFM 显微镜观察获得的 NH。确定了 NH 的杨氏模量，证明了这些纳米系统的柔软性；还评估了纳米悬浮液的临界聚集浓度 (cac)。此后，藻酸盐裂解酶 (AL) 与 NHs 结合，目的是开发一种有用的系统，用于治疗产生藻酸盐生物膜的细菌感染。固定化后测定 AL 的结合效率和酶活性。