ASTM_F_2450_-_18.pdf

Designation:F245018Standard Guide forAssessing Microstructure of Polymeric Scaffolds for Use inTissue-Engineered Medical Products1This standard is issued under the fixed designation F2450;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide covers an overview of test methods that maybe used to obtain information relating to the dimensions ofpores,the pore size distribution,the degree of porosity,interconnectivity,and measures of permeability for porousmaterials used as polymeric scaffolds in the development andmanufacture of tissue-engineered medical products(TEMPs).This information is key to optimizing the structure for aparticular application,developing robust manufacturing routes,and providing reliable quality control data.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D2873 Test Method for Interior Porosity of Poly(VinylChloride)(PVC)Resins by Mercury Intrusion Porosim-etry(Withdrawn 2003)3D4404 Test Method for Determination of Pore Volume andPore Volume Distribution of Soil and Rock by MercuryIntrusion PorosimetryE128 Test Method for Maximum Pore Diameter and Perme-ability of Rigid Porous Filters for Laboratory UseE1294 Test Method for Pore Size Characteristics of Mem-brane Filters Using Automated Liquid Porosimeter(With-drawn 2008)3E1441 Guide for Computed Tomography(CT)ImagingF316 Test Methods for Pore Size Characteristics of Mem-brane Filters by Bubble Point and Mean Flow Pore TestF2150 Guide for Characterization and Testing of Biomate-rial Scaffolds Used in Tissue-Engineered Medical Prod-uctsF2603 Guide for Interpreting Images of Polymeric TissueScaffolds3.Terminology3.1 Definitions:3.1.1 bioactive agent,nany molecular component in,on,or within the interstices of a device that is intended to elicit adesired tissue or cell response.3.1.1.1 DiscussionGrowth factors and antibiotics are typi-cal examples of bioactive agents.Device structural compo-nents or degradation byproducts that evoke limited localizedbioactivity are not bioactive agents.3.1.2 blind(end)-pore,na pore that is in contact with anexposed internal or external surface through a single orificesmaller than the pores depth.3.1.3 closed cell,na void isolated within a solid,lackingany connectivity with an external surface.Synonym:closedpore3.1.4 hydrogel,na water-based open network of polymerchains that are cross-linked either chemically or throughcrystalline junctions or by specific ionic interactions.3.1.5 macropore/macroporosity(life sciences),na struc-ture(including void spaces)sized to allow substantially unre-stricted passage of chemicals,biomolecules,viruses,bacteria,and mammalian cells.In implants with interconnecting pores,macroporosity provides dimensions that allow for ready tissue1This guide is under the jurisdiction of ASTM Committee F04 on Medical andSurgical Materials and Devices and is the direct responsibility of SubcommitteeF04.42 on Biomaterials and Biomolecules for TEMPs.Current edition approved Nov.15,2018.Published December 2018.Originallyapproved in 2004.Last previous edition approved in 2010 as F2450 10.DOI:10.1520/F2450-18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 penetration and microvascularization after implantation.In-cludes materials that contain voids with the potential to beobservable to the naked eye(100 m).3.1.6 micropore/microporosity(life scie