Sterilization is part of the manufacturing process
For printable biomaterials, sterilization cannot be treated as an isolated final step. The study compared autoclaving, aerobic and anaerobic dry heat treatment, 70% ethanol washing, UV irradiation and filtration across Pluronic F127 and two poly(2-oxazoline)/poly(2-oxazine)-based thermoresponsive polymers.
The results show that the sterilization route can materially change the properties that determine whether a formulation remains suitable for additive manufacturing, including chemical stability, gel mechanics, rheology, print fidelity and cytocompatibility.
Some standard approaches compromised performance
Ethanol washing and UV irradiation did not provide reliable sterilization under the tested conditions. Dry heat treatment caused partial thermal degradation across the tested polymers and compromised 3D printability; for Pluronic F127, it also increased cytotoxicity, consistent with the formation of oxidative degradation products.
By contrast, filtration sterilized both tested pMeOx-based block copolymers effectively. Pluronic F127 required a combined approach of autoclaving and triple filtration to achieve complete sterility in the study.
- Sterilization method influenced polymer chemistry and rheological behaviour.
- Dry heat treatment reduced printability and caused partial thermal degradation.
- UV irradiation and ethanol washing were insufficient under the evaluated conditions.
- Filtration was effective for both tested pMeOx-based polymers.
- Autoclaving combined with triple filtration achieved complete sterility for Pluronic F127.
Printability evaluated on Brinter One
The 3D-printability assessment was performed using the extrusion-based Brinter One platform with a pneumatically driven print head. The study compared printed grid quality after the different sterilization treatments, linking material-level changes directly to manufacturing performance.
This is an important point for process development: a biomaterial may still appear usable after sterilization while its extrusion behaviour, shape fidelity or biological compatibility has already shifted enough to affect downstream manufacturing.
Why this matters for scalable biofabrication
The study provides practical evidence that sterilization strategy should be considered during formulation and process development rather than added only at the end of R&D. For reproducible and eventually scalable biofabrication, material formulation, sterilization, dispensing conditions and printability need to be validated as one connected manufacturing workflow.
For AM Technologies by Brinter, the work is another example of the role manufacturing platforms can play in understanding how material science and process conditions interact before a biofabrication workflow can move toward reliable production.