Sterilization of hydrogels for biomedical applications: A review

Abstract

Despite the beneficial properties and outstanding potential of hydrogels for biomedical applications, several unmet challenges must be overcome, especially regarding to their known sensitivity to conventional sterilization methods. It is crucial for any biomaterial to withstand an efficient sterilization to obtain approval from regulatory organizations and to safely proceed to clinical trials. Sterility assurance minimizes the incidence of medical device-related infections, which still constitute a major concern in health care. In this review, we provide a detailed and comprehensive description of the published work from the past decade regarding the effects of sterilization on different types of hydrogels for biomedical applications. Advances in hydrogel production methods with simultaneous sterilization are also reported. Terminal sterilization methods can induce negative or positive effects on several material properties (e.g., aspect, size, color, chemical structure, mechanical integrity, and biocompatibility). Due to the complexity of factors involved (e.g., material properties, drug stability, sterilization conditions, and parameters), it is important to note the virtual impossibility of predicting the outcome of sterilization methods to determine a set of universal rules. Each system requires case-by-case testing to select the most suitable, effective method that allows for the main properties to remain unaltered. The impact of sterilization methods on the intrinsic properties of these systems is understudied, and further research is needed. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2472-2492, 2018.

Crosslinking of hydrophilic polymers using polyperoxides

“…Thermal treatment at high temperatures potentially allows concurrent crosslinking and sterilization of the chosen polymers. Common methods of sterilization of hydrogels for biomedical application are steam heating (121-124°C at 1 bar for not less than 15 min) or dry heating (minimum of 180°C for not less than 30 min) [53]. In addition we suppose that the proposed method also provides endotoxin removal from the hydrogel material [54].…”

Autoclave sterilization of tetra‐polyethylene glycol hydrogel biomaterials with β‐eliminative crosslinks

“…Sterility is an important requirement for degradable polymeric biomaterials intended for injection, and sterilization of such materials is a crucial process to minimize the incidence of infections; for recent reviews on sterilization of biocompatible polymers see References , and . A foremost consideration in choosing a sterilization method is whether the biomaterial will sustain the procedure, and there is no single technique that can achieve sterilization of a wide variety of degradable materials without adverse effects; each system requires testing to ensure relevant properties of the material are not altered.…”

“…We are surmounting the first challenge by developing a multichannel microfluidics apparatus functionally similar to the Dolomite high‐throughput Telos system; clearly, other droplet forming approaches could also be used for this purpose. However, as recently reviewed, aseptic manufacturing of microparticles is a formidable task. To overcome this challenge, we initially planned to couple the Stage 1 amine‐MS formation and Stage 2 drug attachment steps in a single sterilized, sealed apparatus.…”

Nanopharmaceuticals for Eye Administration: Sterilization, Depyrogenation and Clinical Applications

“…To sum up, HGs are mainly sensitive to conventional sterilization methods. Some of them cause physicochemical alterations that may impact on the mechanical properties and biocompatibility, as well as on the efficacy of the loaded therapeutic compounds [ 69 ]. Pre-processing of the polymers has affected mechanical properties of the HG.…”