Analysis of sterilization protocols for peptide‐modified hydrogels

Abstract

Concerns about the efficacy of ethanol disinfection for implanted biomaterials prompted investigation of an alternative sterilization process, ultraviolet irradiation, for terminal sterilization of N-isopropylacrylamide-based hydrogels containing biomimetic peptides. Ultraviolet irradiation is more easily applied on a laboratory scale than gamma irradiation or electron beam, two commercially utilized methods; thus, UVC irradiation was investigated as a low-cost sterilization procedure that might be performed in laboratories prior to in vivo studies. UVC irradiation at 400 muW/cm(2) for up to 15 h did not prevent growth of Escherichia coli within the hydrogels, while ethanol disinfection did prevent growth for the duration of the experiment (120 h). Furthermore, UVC irradiation caused progressive degradation of peptides containing the Arg-Gly-Arg (RGD) domain. UVC irradiation cannot be used as a terminal sterilization process for peptide-modified materials. The system used in this study is not intended to be adequate for evaluating the sterility of medical devices in accordance with current Good Manufacturing Practice (cGMP); however, it remains a useful, low-cost system for the preliminary evaluation of sterilization procedures in terms of their ability to eliminate pathogenic organisms while preserving the structure of biologically active molecules within in a laboratory setting. Ethanol treatment is still the preferred method for disinfection of bioactive materials containing peptides or UV-degradable groups.

Hydrogen peroxide generation and biocompatibility of hydrogel-bound mussel adhesive moiety

“…Hydrogels were sterilized by submersing the samples in 70% (v/v) ethanol for 45 min and washed three times with 20 mL PBS for 90 min [35, 36]. The sterilized hydrogels were transferred into a 24-well plate and incubated with 1 mL of L929 cell culture medium, prepared with DMEM (addition of 10% (v/v) FBS and 0.5% (v/v) Penicillin-Streptomycin) and incubated for 1–48 h (37°C, 5% CO 2 and 95% air).…”

Physicochemical Characterization and Drug Release of Thermosensitive Hydrogels Composed of a Hyaluronic Acid/Pluronic F127 Graft

“…Sterilization under ambient temperature such as ultraviolet irradiation, high hydrostatic pressure, nanometer-scale filtration, and ethylene oxide treatment may be the methods for the thermosensitive systems. 26) Further experiment is needed to elucidate the suitable sterilization protocols.…”

Cellulose-based hydrogels with excellent microstructural replication ability and cytocompatibility for microfluidic devices

“…This is an excellent feature enabling a common and low-cost sterilization method to be performed. In contrast, the structures and functions of many other hydrogels derived from nature considered for application in microfulidic devices or cell culture will usually be damaged under high pressure steam sterilization, and they are usually sterilized by ultraviolet light or alcohol (Huebsch et al 2005). Having placed the RCC hydrogel in a bath of cell culture media for 2 days, the hydrogel was equilibrated with the media, and it turned pink because phenol red came inside.…”