ASTM_F_2450_-_10.pdf

Designation:F245010Standard 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 guide does not purport to address all of the safetyconcerns,if any,associated with its use.It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and to determine the applicability of regula-tory limitations prior to use.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Standards:2D2873 Test Method for Interior Porosity of Poly(VinylChloride)(PVC)Resins by Mercury Intrusion Porosim-etry(Withdrawn 2003)3D4404 Test Method for Determination of Pore Volume andPore Volume Distribution of Soil and Rock by MercuryIntrusion PorosimetryE128 Test Method for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 tissuepenetration 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 sciences),na struc-ture(including void spaces)sized to allow substantially unre-stricted passage of chemicals,biomolecules,and viruses whilesized to control or moderate the passage of bacteria,mamma-lian cells,and/or tissue.Includes materials with typical pore1This 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 March 1,2010.Published April 2010.Originallyapproved in 2004.Last previous edition approved in 2009 as F2450 09.DOI:10.1520/F2450-10.2For 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 States1 sizes of greater than 0.1 m(100 nm)and less than about 100m(100 000 nm),with a common microporous context en-compassing the range of 20 m or less for the filtration of cellsranging from bacteria to common mammalian cells and above30 m for the ingrowth of tissue.Objects in this size rangetypically can be observed by conventional light microscopy.3.1.7 nanopore/nanoporosity(life sciences),na str