Abstract
Since porous and injectable bioceramics have recently been utilized often as scaffolds for bone regenerative medicine, the need for their standardization has increased. One of the standard proposals in ISO/TC150 and JIS has been a draft for characterization of the porous bioceramic scaffolds in both micro- and macro-scopic aspects. ISO/TC150/SC7 (Tissue engineered medical products) has been co-chaired by Professor J E Lemons, Department of Surgery, University of Alabama at Birmingham and Dr R Nakaoka, Division of Medical Devices, National Institute of Health Sciences, Japan. The scope of SC7 has been specified as ‘Standardization for the general requirements and performance of tissue engineered medical products with the exclusion of gene therapy, transplantation and transfusion’.
International standardization organizations
The representative bodies of international standardization for biomaterials and medical devices are ISO and ASTM international. The ISO/TC150/SC7 (International Organization for Standards/Technical Committee 150 for Implants for Surgery/Sub Committee 7 for Tissue Engineered Medical Products; see appendix A) has been established in 2007 and was proposed and organized in Japan as international secretariat. In harmonization with the international activities in ISO/TC150/SC7, ISO/TC194/SC1 (Biological evaluation of medical devices) and ASTM/F04 (American Society for Testing and Materials/Medical and Surgical Materials and Devices), the Japanese standardization trends have been accelerated rapidly.
Tissue engineered medical products
Most of the standards for the tissue-engineered medical products should be fundamentally different in their characteristics from the conventional de facto standards which have been based on the market perception and/or interchangeability. They should be de jure standards, which are the constitutional rules or guidelines in order to establish new preferable medical products.
At the last annual meeting of ISO/TC150 in Kyoto held in 7ndash;11 September, 2009, the activities of the two working groups in SC7 were summarized as listed in appendix B. The most active group was WG3 aimed at tissue-engineered medical products for skeletal tissues. Several new topics were drafted towards the next annual meeting in Orlando, USA, such as (i) Evaluation of in vivo bone formation in porous materials using rat mesenchymal stem cells and (ii) Quantification of sulphated glycosaminoglycans (sGAG) in regenerated articular cartilage, and others.
Because all the drafts are protected by the ISO copyrights, the details of those drafts can only be found in the authorized reports at the JISC and/or ISO homepages.
Bioceramics
The recent standardizing activities on calcium phosphate ceramics, defined here as ‘Bioceramics’, including ceramic biomaterials for medicine and dentistry, are shown in appendix C as resolutions of the IOS/TC150 Kyoto Meeting. Among them, Japanese drafts on calcium phosphates have been incorporated and harmonized with the French draft which was proposed just before Japanese schedule in 2009. The advantages of Japanese drafts are to establish more quantitative analytical methods in porous structural characteristics for strength, pore sizes, solubility, etc, focusing onto bioceramics which were studied within a NEDO project (Dr Kikuchi at National Institute for Materials Science) and a VAMUS project (Dr Ito at the National Institute of Advanced Industrial Science and Technology).
Japanese standardization
Our activities, both in international and Japanese standardization, have been progressing alongside, but sometimes shifted in time.
For instance, the standard ‘Test method for impact resistance of fine ceramic femoral head for hip joint prostheses’ was issued as JIS T0308 in 2008, but it has been still in the pre-proposing stage in ISO/TC150/SC4 due to international discussion on its significant difference from the static evaluation.
Another important draft on cement-type calcium phosphates has been prepared both for JIS and ISO at the same time.
Notes
1 Objects or devices which are surgically implanted in the body, either temporarily or permanently, for diagnostic or therapeutic purposes.
Appendix A Structure of ISO/TC150 (Implants for Surgery)
Secretariat: DIN Secretary: Dr Gabriele Troescher Chair: Mr J P Hallett (UK) until end 2011
Scope: Standardization in the field of implants for surgeryFootnote1, and their required instrumentation, covering terminology, specifications and methods of tests for all types of implants and for the materials, basic and composite, used in their manufacture and application.
Committee title:
TC 150/WG 7 Fundamental standards
TC 150/WG 8 Breast implants
TC 150/WG 10 Data on implanted and retrieved devices
TC 150/SC 1 Materials
TC 150/SC 2 Cardiovascular implants and extracorporeal systems
TC 150/SC 3 Neurosurgical implants
TC 150/SC 4 Bone and joint replacements
TC 150/SC 5 Osteosynthesis and spinal devices
TC 150/SC 6 Active implants
TC 150/SC 7 Tissue engineered medical products
Appendix B Working Groups in ISO/TC150/SC7 (Tissue Engineered Medical Products) and last resolutions in 2009
WG2 ‘Guideline of safety test’ by Professor Hwal Suh
Resolution 22 (Kyoto Resolution 2): ISO/TC 150/SC 7 accepts recommendation from WG2 to alter the title of the document; also, many changes were introduced into the text. Proposed new work item is still under ballot which will close in November 2010. ISO/TC 150/SC 7 cannot take any further action until then. Japan and US agreed to nominate experts for WG2. ISO/TC 150/SC 7 looks forward to a report on the result of the ballot at the next meeting.
WG3 ‘Tissue-engineered medical products for skeletal tissues’, by Dr Atsuo Ito
Resolution 23 (Kyoto Resolution 3): WG3 documents were balloted and the documents were revised per comments received by the UK counterpart. Not enough positive votes were received and ISO/TC 150/SC 7 recommends that these documents be re-balloted as NPs (New Projects). Korea, Sweden, and US agreed to nominate experts for the NPs. Brazil and China agreed to take back WG3 recommendation to their member bodies for formal application as P-members (Participating-members) and nomination of experts.
Items for future work
Resolution 24 (Kyoto Resolution 4): ISO/TC 150/SC 7 appreciates the presentation on ‘Evaluation of anisotropic structure of articular cartilage using DT (diffusion tensor)-MR imaging’ (ISO/TC 150/SC 7 N35) by Prof. S. Tsutsumi, Japan as a future preliminary work item. The work item will be submitted as a preliminary work item.
Resolution 25 (Kyoto Resolution 5): ISO/TC 150/SC 7 received a report from Dr David Kaplan on ‘General documentation’. The report was referred to WG2 for harmonization with the proposed document entitled ‘Guidance of Human and Animal Cell-based Implants-General Requirements’ which currently under the ballot.
Resolution 26 (Kyoto Resolution 6): ISO/TC 150/SC 7 accepts a creation of WG4 under the leadership of Dr David Kaplan. ISO/TC 150/SC7 looks forward to receiving a report at a next meeting regarding working group scope and proposed work item.
Requirements concerning a subsequent meeting
Resolution 27 (Kyoto Resolution 7): ISO/TC 150/SC 7 agrees to meet with ISO/TC 150 in Orlando, USA, in September 2010.
Appendix C Working Groups in ISO/TC150/SC1 (Materials) and last resolutions in 2009
Resolution 487: ISO/CD 6474-2 ‘Implants for surgery—Ceramic materials—Part 2: Composite materials based on a high purity alumina matrix with zirconia reinforcement’ (8 Kyoto 2009)
Taking into account the result of the vote on the CD (Committee Draft) (N 703) and the discussions during the meeting, ISO/TC 150/SC 1 agreed to accept the manuscript as prepared by the Ceramics Task Force as manuscript for DIS (Draft International Standard). The project leader is kindly requested to hand in the manuscript to the secretariat before the end of October 2009.
Resolution 492: ISO/NP 13175-3 ‘Implants for surgery—Calcium phosphates—Part 3: Hydroxyapatite and beta-tricalcium phosphate bone substitutes’ (13 Kyoto 2009)
Taking into account the manuscript as prepared by the project leader (N 723), ISO/TC 150/SC 1 agreed to circulate the manuscript as amended by the Ceramics Task Force as Committee Draft. The project leader is kindly requested to hand in the manuscript to the secretariat before the end of November 2009.
Resolution 493: ISO/NP 23317—Revision of ISO 23317:2008 ‘Implants for surgery—In vitro evaluation for apatite-forming ability of implant materials’ (14 Kyoto 2009)
Taking into account the result of voting on the New Work Item Proposal (N 686) and the explanations of the secretary, ISO/TC 150/SC 1 agreed to circulate the manuscript as amended by the project leader as Committee Draft.
Resolution 494: ISO/PWI 13175-1 ‘Implants for surgery—Calcium phosphates—Part 1: Hydroxyapatite powders’ and ISO/PWI 13175-2 ‘Implants for surgery—Calcium phosphates—Part 2: beta-tricalcium phosphate powders’ (15 Kyoto 2009)
Considering that no additional expert nominations were received, these work items have to remain in the preliminary stage. The secretariat noted the nomination of an additional expert from Japan, accompanied with a disapproval.
Resolution 496: ISO/PWI 13779-5 ‘Implants for surgery—Hydroxyapatite—Part 5: Analysis of hydroxyl apatite coatings morphology’ (17 Kyoto 2009)
After considering the result of the NWIP ballot on this work item and the explanations of the project leader Dr Bignon concerning the amendments in the document, ISO/TC 150/SC 1 noted that only nominations from UK, Japan, France and Austria were received. SC 1 concluded that the work item has to remain in the preliminary stage.
Resolution 499: Proposal of French member body concerning revision of ISO 13779-2:2008 (20 Kyoto 2009)
Considering the proposal as handed in by the French member body to amend ISO 13779-2 and that the item could not be addressed during the Ceramics task force, ISO/TC150/SC 1 decided to kindly request the French member body to submit a new work item proposal in this respect.