Hydrogels based on poly(ethylene glycol) as scaffolds for tissue engineering application: biocompatibility assessment and effect of the sterilization process

Abstract

Hydrogels are suitable materials to promote cell proliferation and tissue support because of their hydrophilic nature, porous structure and sticky properties. However, hydrogel synthesis involves the addition of additives that can increase the risk of inducing cytotoxicity. Sterilization is a critical process for hydrogel clinical use as a proper scaffold for tissue engineering. In this study, poly(ethylene glycol) (PEG), poly(ethylene glycol)-chitosan (PEG-CH) and multi-arm PEG hydrogels were synthesized by free radical polymerization and sterilized by gamma irradiation or disinfected using 70 % ethanol. The biocompatibility assessment in human fibroblasts and hemocompatibility studies (hemolysis, platelet aggregation, morphology of mononuclear cells and viability) in peripheral blood from healthy volunteers (ex vivo), were performed. The sterilization or disinfection effect on hydrogel structures was evaluated by FT-IR spectroscopy. Results indicated that hydrogels do not induce any damage to fibroblasts, erythrocytes, platelets or mononuclear cells. Moreover, there was no significant difference in the biocompatibility after the sterilization or disinfection treatment. However, after gamma irradiation, several IR spectroscopic bands were shifted to higher or lower energies with different intensity in all hydrogels. In particular, several bands associated to carboxyl or hydroxyl groups were slightly shifted, possibly associated to scission reactions. The disinfection treatment (70 % ethanol) and γ-irradiation at 13.83 ± 0.7 kGy did not induce morphological damages and yielded sterile and biocompatible PEG hydrogels potentially useful for clinical applications.

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.…”

Characterization of ketoprofen‐loaded PEG‐CH semi‐IPN system for wound dressing application

“…Free radical polymerization is a useful method for the formation of crosslinked materials with different applications (i.e., controlled drug release). Here, UV light dissociated the photoinitiator (AIBA) into free radicals that initiate polymerization of PEGDA to form the network (Figure ).…”

“…PEGDA (10% v/v) was dried under vacuum to constant weight and homogenized with AIBA in deionized water. CH (1% v/v) in acetic acid (1%) was mixed with PEGDA solution and polymerized (UV light, 365 nm, for 15 min) (Figure ).…”

Drug Micro-Carriers Based on Polymers and Their Sterilization

“…Although both processes cooccur, if cleavage dominates over cross-linking, the molecular weight decreases; the process is called degradation. However, if the irradiation increases molecular weight, the process involves crosslinking [296][297][298][299][300][301].…”