Table 3.

Summary of the published papers related to the sterilization of 3D printing of PLA for biomedical devices.

3D Printing Materials	Sterilization Method	Characterization Method		Effects of Sterilization	References
		Physicochemical Evaluation	Biological Evaluation
PLA for biomodels	Autoclave	Changes in area, volume and deformity by scanning	Sterility tests	Following their printing protocols and autoclave at 134 °C the pieces, it is safe and does not significantly alter the morphology of biomodels	[31]
HTPLA custom cutting guides (CCG) for pediatric orthopaedic surgery	Autoclave	Design geometry (visual inspection) Mechanical properties	-	A HTPLA-printed CCG was produced and sterilized aggressively, maintaining its mechanical properties and design geometry	[32]
PLA pieces	Autoclave	Mechanical resistance (breaking load/deformation/permeability)	Sterility tests	Autoclave sterilization of PLA-printed pieces is safe for the patient and mechanically strong for the surgeon	[30]
PLA cylinders for bone model	EtO Gas Plasma Steam heat (autoclave)	Visual deformation	Bacterial growth of contaminated cylinders	Steam heat deformed completely the pieces. Gas Plasma does not eliminate all microorganisms Recommends the EtO in hospitals	[15]
PLA Genioplasty Guide	HPGP (Sterrad®)	Volumetric deformation	-	Acceptable for surgical use (<1 mm)	[39]
PLA bone model	Autoclave	Size analysis	-	Acceptable for surgical use (<1 mm)	[29]
PLA scaffolds	Gamma radiation	-	Cytotoxicity Live/Dead assay	Biocompatible scaffolds, with bone cell colonization	[43]
PLA for laboratory equipment	3D printing extrusion	-	Cell culture Microbiological tests	The extrusion process sterilizes the piece, with possible applications in experiments with bacteria and cells	[55]
PLA (1% gentamicin) for biomedical applications	H2O2 vapour	Mechanical properties Physical changes (dimension, mass, colour)	-	Changes in colour, mass and mechanical properties, which may not be significant depending on the application	[11]
PLA surgical retractors	2.4% glutaraldehyde solution 3D printing extrusion	Strength test	Polymerase chain reaction (PCR) to test bacterial load	Material extruded in a clean environment produces a ready-to-use sterile instrument. Residuals of bacterial nucleic acids were found after sterilization by glutaraldehyde, but it is attributed to the high sensitivity of the test (residuals belonging to dead bacteria) Strong enough for the demands of the operating room.	[38]

Abbreviation: EtO: ethylene oxide; HPGP: hydrogen peroxide gas plasma.