[Thoughts on the Biological Evaluation of Biodegradable Cardiovascular Implants].

In recent years, new degradable materials have been applied to cardiovascular implants. Cardiovascular implants with different physicochemical properties and degradation properties have special endpoints for their biological evaluation. In this study, the end points of biological evaluation of degradable cardiovascular implants were reviewed by taking vascular stents and occluders as examples.

[Regulatory Consideration for Animal Study of Medical Device].

Animal study plays a key role to evaluate the safety and effectivity of medical devices. This study aims to share evaluated consideration on the role, general principles, necessity, study design and quality management system of animal study, in order to improve the quality of animal study and reduce unnecessary study.

[Evaluation of Lubrication Coatings for Intravascular Catheters, Wires, and Delivery System].

Lubrication coating is widely used to reduce the friction between the interventional devices and the blood vessels, improves the surface biocompatibility of the interventional device, and also brings the coating stability problems and related risks. This paper describes the coating-related content from the equipment description, performance verification, technical requirements, etc., to reduce the risk of the coating to an acceptable level.

[Bacterial Endotoxin for Intrathoracic Medical Devices Requirement Revisited].

Bacterial endotoxin is considered as one of the critical risk factors in medical devices, especially implanted devices that directly or indirectly contact with blood circulating system. In that case, endotoxin limits for implanted medical devices is important in determine the safety of medical devices. According to GB/T 14233.2-2005, the requirements of endotoxin index for intrathoracic medical devices is 2.15 EU per device. However, the definition of "intrathoracic medical devices" is vague. Specifically, "for cardiovascular system application" instead of "intrathoracic application" is more reasonable. With the deeper understanding of the risk of endotoxin in medical devices and considering the internationally accepted standards, the limits of endotoxin in medical devices for cardiovascular system application is acceptable at 20 EU per device.

[The Enhancement of Ultrasonic Visibility and Technical Requirements of Needles and Catheters].

Ultrasound guided needle biopsy or catheterization is a rising operation in clinical diagnosis and treatment. However, poor visualization under ultrasound is the main disadvantage of this technique. This paper summarized the basic methods used to solve such problem, as well as the corresponding product technical requirements.

[The Exploration of Design and Consideration Factors of Aortic Stent Graft System Clinical Trial].

Aortic disease is a dangerous and critical cardiovascular disease with a high mortality rate. In recent years, aortic stent grafts for endovascular treatment have become widely used, and the development of new aortic stent grafts has been a hot spot for cardiovascular medical devices. How to carry out a reasonable and scientific clinical trial is the key in the design confirmation of aortic stent graft system. The nature, location, segment, applicable population, biomechanics and other factors of aortic disease should be considered. The effectiveness and safety endpoint, trial design type should be carefully and reasonably studied.

[The research progress of transcatheter aortic valve replacement].

During the past years transcatheter aortic valve replacement has evolved to a promising technique for the treatment of the patients who suffered from severe aortic stenosis, the progress and basic consideration on clinical study have been summarized in the article.

[The authorized considerations on the pre-clinical study of drug-eluting coronary stent system].

China Food and Drug Administration didn't issue any guideline on the pre-clinical study of drug-eluting coronary stent system, the basic requirement of the authorized administration was summarized to help manufacture prepare the document during the registration process.

Regulatory perspectives of combination products.

Combination products with a wide range of clinical applications represent a unique class of medical products that are composed of more than a singular medical device or drug/biological product. The product research and development, clinical translation as well as regulatory evaluation of combination products are complex and challenging. This review firstly introduced the origin, definition and designation of combination products. Key areas of systematic regulatory review on the safety and efficacy of device-led/supervised combination products were then presented. Preclinical and clinical evaluation of combination products was discussed. Lastly, the research prospect of regulatory science for combination products was described. New tools of computational modeling and simulation, novel technologies such as artificial intelligence, needs of developing new standards, evidence-based research methods, new approaches including the designation of innovative or breakthrough medical products have been developed and could be used to assess the safety, efficacy, quality and performance of combination products. Taken together, the fast development of combination products with great potentials in healthcare provides new opportunities for the advancement of regulatory review as well as regulatory science.

Regulatory considerations for animal studies of biomaterial products.

Animal studies play a vital role in validating the concept, feasibility, safety, performance and efficacy of biomaterials products during their bench-to-clinic translation. This article aims to share regulatory considerations for animal studies of biomaterial products. After briefly emphasizing the importance of animal studies, issues of animal studies during biomaterial products' translation are discussed. Animal studies with unclear purposes, flawed design and poor reporting quality could significantly reduce the translation efficiency and create regulatory challenges. Regulatory perspectives on the purpose, principle, quality and regulatory science of animal studies are also presented. Animal studies should have clear purposes, follow principles of 3R+DQ (replacement, reduction, refinement, design and quality) and execute under an efficiently operating quality management system. With the advancement of regulatory science, National Medical Products Administration of China has been developing a series of standards and guidance documents on animal studies of medical devices. Case studies of making decisions on whether to conduct animal studies are provided in the end with drug-eluting stents as examples. In summary, animal studies of biomaterial products should pay close attention to the rationale, design and quality in order to achieve their purposes.

Biodegradable metals for bone defect repair: A systematic review and meta-analysis based on animal studies.

Biodegradable metals are promising candidates for bone defect repair. With an evidence-based approach, this study investigated and analyzed the performance and degradation properties of biodegradable metals in animal models for bone defect repair to explore their potential clinical translation. Animal studies on bone defect repair with biodegradable metals in comparison with other traditional biomaterials were reviewed. Data was carefully collected after identification of population, intervention, comparison, outcome, and study design (PICOS), and following the inclusion criteria of biodegradable metals in animal studies. 30 publications on pure Mg, Mg alloys, pure Zn and Zn alloys were finally included after extraction from a collected database of 2543 publications. A qualitative systematic review and a quantitative meta-analysis were performed. Given the heterogeneity in animal model, anatomical site and critical size defect (CSD), biodegradable metals exhibited mixed effects on bone defect repair and degradation in animal studies in comparison with traditional non-degradable metals, biodegradable polymers, bioceramics, and autogenous bone grafts. The results indicated that there were limitations in the experimental design of the included studies, and quality of the evidence presented by the studies was very low. To enhance clinical translation of biodegradable metals, evidence-based research with data validity is needed. Future studies should adopt standardized experimental protocols in investigating the effects of biodegradable metals on bone defect repair with animal models.

Characterization of water-in-oil microemulsion for oral delivery of earthworm fibrinolytic enzyme.

Earthworm fibrinolytic enzyme (EFE-d, Mr 24177), a water-soluble protein, is clinically used for the management of cardiovascular diseases. However, this protein drug has a very low oral bioavailability because of its low oil/water partitioning, low membrane permeability and unstable nature in harsh gastric juice. This study explored the possibility of absorption and efficacy enhancement for EFE-d through the delivery of the water-in-oil (w/o) microemulsions. The w/o microemulsion consisting of Labrafac CC, Labrasol, Plurol Oleique CC 497 and saline (54/18/18/10, % w/w) was developed and characterized, including conductivity, viscosity, particle size and in vitro membrane permeability. The w/o microemulsion and the control solution of EFE-d were administered intraduodenally (or orally) to rats. The w/o microemulsion possessed a higher intestinal membrane permeability in vitro as well as a higher absorption and efficacy in vivo, when compared to control solution. The intraduodenal bioavailability of EFE-d for microemulsions was 208-fold higher than that of control solution and the absolute bioavailability was 17.55%. Meanwhile, there was no tissue damage of the intestinal mucosa found after oral multiple-dose administration of the EFE-d microemulsion to rats. These findings indicated that the w/o microemulsion may represent a safe and effective oral delivery system for hydrophilic bioactivity macromolecules.