ABSTRACT
Polypropylene mesh, integrated in N95 respirators and surgical masks that are widely used in the current crisis of COVID-19, filters aerosols via electrostatics in addition to the physical block. However, any contact to water such as storage under high humidity, exposure to exhaling breath, and washing in water removes its charges and thus compromises its filtering efficiency. We developed a desk top device based on a Cockcroft-Walton's voltage multiplier that can restore the electrostatic charge of surgical masks within 1 min and recover the filtering efficiency of the polypropylene mesh from 87% to 97%. The device is easy to operate and safe, thus may be applied for the reuse of surgical masks towards reducing the plastic wastes.
ABSTRACT
The aims of this study were to investigate the premarket assessment of autologous chondrocyte implantation (ACI) products especially regarding the non-clinical assessment by surveying the guidelines and review reports of authorized ACI products in detail and to provide information regarding the non-clinical assessment of the safety and efficacy for the future development of regenerative medicine products to design effective premarket assessment. The non-clinical assessment plays a role in justifying the testing of investigational products in humans. Effective non-clinical assessments minimize the risk of clinical trials and achieve prompt product development. In this study, we focused on authorized ACI products that remain in the body of patients for a long time and often contain extrinsic components such as animal tissue-derived collagen. We summarized the details of the characteristics of each ACI product, non-clinical assessment design and related guidelines. To design effective non-clinical assessments, we discussed the evaluation method (particularly the validation of clinical assessment and mechanical property testing), the employed animal models, and the differences in the assessment of the safety and efficacy of the products. Based on these investigations, we provide the details of satisfactory non-clinical assessment of ACI products and indicate the possibility of more effective non-clinical assessment of ACI products and other future regenerative medicine products.
ABSTRACT
Human cells and tissue products belong to a relatively new class of medical products. Therefore, limited information is available on the classification and premarket evaluation of human cells and tissue products in the United States (US), the European Union (EU), and Japan. In this study, the definition, legislation, and approval system of these products were surveyed. A total of nine autologous human cells and tissue products approved until October 2013 were collected. The definitions of human cells and tissue products were compatible among the US, the EU and Japan. The products were classified as human cells, tissue, and cellular and tissue-based products (HCT/Ps) in the US, advanced therapy medicinal products (ATMPs) in the EU, and cell/tissue-engineered products in Japan. These products were categorized as biologics and medical device in the US and Japan, and drug in the EU. The issuance of new guidance induced regulatory impact for manufacturer, especially in the US. These products are subjected to the accelerated approval of biological product, the humanitarian device exemption approval, the premarket application approval, the biologics license application approval, and new drug application approval with specific targeting of postapproval registry or surveillance. Of nine autologous human cells and tissue products, four products had been evaluated using clinical experiences or open clinical trials with small subjects, although the rests of products had been evaluated using comparative clinical trials with control treatment. Our survey suggests that autologous human cells and tissue products would need postmarket-oriented evaluation rather than premarket-oriented evaluation for doctors and patients.
