Work Item
ASTM WK72274

New Test Method for Printability of Bioinks for Extrusion-based Bioprinting

1. Scope

1. Scope 1.1 This standard describes procedures to evaluate printability of bioinks including material inks without cells used during extrusion-based bioprinting. Bioprinting is a 3D printing technique for synthesizing living tissues for applications within regenerative medicine, tissue engineering, disease modeling and drug testing. 1.2 This test method is intended for use by manufacturers and researchers to assess and compare printability of bioinks including material inks without cells that can be printed in air without requiring any support medium. Printability of support materials could also be assessed by this test method. Printability is one of several important parameters for precision manufacturing of 3D bioprinted parts. 1.3 The two test methods described in this printability specification involve using an extrusion-based bioprinter to either (a) extrude multiple single thickness straight lines of bioink with one line horizontally crossing three other vertical lines or (b) build up a wall of bioink of multiple single lines deposited on top of each other. While this test method evaluates print parameters of straight lines, other geometries such as curved lines are also bioprinted. 1.4 The test methods provide information on the physical capability of a material with or without living cells or other biological components to (a) be extruded reproducibly through a nozzle during extrusion-based bioprinting, (b) to span gaps, and (c) to maintain printed shape and dimensions during the addition of multiple layers above existing layers. Conducting these test methods result in measurements of line thicknesses, continuity, geometry and wall height without a judgement of pass or fail. 1.5 The effects of bioprinting on viability and function of cells or other biological or drug components that may be contained in the bioink are not addressed in this standard. 1.6 The values are stated in SI units. No other units of measurement are included in this standard.

Keywords

bioprinting; bioinks; 3D printing

Rationale

Ballot Rationale The field of bioprinting is a subset of additive manufacturing that is rapidly expanding to meet the needs of the regenerative medicine and tissue engineering community. Bioprinting, together with 3D imaging approaches, can be used to assemble combinations of biomaterials and cells with controlled composition, geometry, and structural integrity. It is a way to synthesize organs and tissues for applications within reconstructive medicine, tissue engineering and drug testing. As an rapidly developing industry, there are a plethora of manufacturers and academic researchers developing bioinks, the substance that is deposited or extruded by a 3D bioprinter. There is a currently a lack of standardization for bioink properties resulting in issues with reproducibility that may slow clinical implementation of this technology. This draft standard describes a test method to measure printability of bioinks made of any material, with or without living cells or biologics, when using an extrusion based bioprinter. Extrusion based bioprinters are the most commonly used machines at this time. The test method is meant to facilitate advancements in bioprinting through standardization and future round robin testing of a wide range of bioinks so that comparisons can be readily and uniformly made between materials and machines.

The title and scope are in draft form and are under development within this ASTM Committee.

Details

Developed by Subcommittee: F04.42

Committee: F04

Staff Manager: Kathleen Chalfin

Work Item Status

Date Initiated: 03-13-2020

Technical Contact: Liisa Kuhn

Item: 001

Ballot: F04.42 (20-01)

Status: Will Reballot Item

Item: 001

Ballot: F04.42 (20-02)

Status: Will Reballot Item