Against the backdrop of Chinas booming medical aesthetics industry and growing demand for facial rejuvenation, polydioxanone (PPDO) facial implant threads, as critical minimally invasive facial lifting medical devices, directly impact public health and safety rights. The National Medical Products Administration (NMPA) consistently adheres to a people-centered approach to health, strictly implements the "Four Stricts" requirements (the most rigorous standards, strictest supervision, severest penalties, and most serious accountability), and continuously improves the whole-life-cycle supervision system for medical devices.
As Class III high-risk medical devices (Classification Code: 13-09-02), PPDO facial implant threads require comprehensive R&D and registration strategies to ensure compliance and successful market access.
China's medical aesthetics industry is booming with a continuously growing demand for facial rejuvenation. As key medical devices for minimally invasive facial lifting, polydioxanone (PPDO) facial implant threads directly affect public health and legitimate rights and interests. The National Medical Products Administration (NMPA) always adheres to a people-centered health philosophy, strictly implements the "Four Stricts" requirements, and continuously improves the full lifecycle supervision system for medical devices.
Faced with increasingly stringent regulatory requirements, enterprises must formulate systematic registration strategies at the product research and development stage and integrate compliance principles throughout design and development, performance verification, biological evaluation, and clinical trials. Based on the current regulatory framework, this article focuses on the core technical review points for the registration of PPDO facial implant threads, conducting in-depth analysis from multiple dimensions including product classification definition, raw material quality control, structural design verification, biological evaluation, and clinical trial design. It aims to provide scientific, standardized and actionable registration guidance for medical device R&D enterprises, facilitate innovative industrial development on the premise of firmly safeguarding the safety bottom line, and better satisfy people's yearning for a better life.
Scientific supervision boosts industrial development, and compliant innovation underpins the future. We work together to drive high-quality development with high standards and guarantee high-level innovation with rigorous supervision, promoting the steady and sustainable development of China’s medical aesthetic device industry.
In March 2022, NMPA issued Announcement No.30 of 2022 on Partial Revision to the Catalogue for Classification of Medical Devices, stipulating that facial implant threads, facial lifting threads and facial cone lifting threads shall be regulated as Class III medical devices, marking a new round of tightened supervision over such products.
Polydioxanone (PPDO) facial implant threads fall under Code 12 (Passive Implantable Devices) – 09 (Plastic and General Surgical Implants). Designed for implantation into the superficial musculoaponeurotic system (SMAS) and overlying facial tissues, they are subject to the strictest tier of regulatory control. Notably, despite sharing PPDO raw material and soft tissue suturing indications with conventional absorbable surgical sutures, facial lifting threads are explicitly excluded from the clinical evaluation guidelines applicable to routine surgical sutures.
In 2024, CMDE released Recommended Clinical Evaluation Pathways for Products in the Medical Device Classification Catalogue (2024 Supplement, Announcement No.11 of 2024), which further clarifies that such products shall in principle complete clinical evaluation via investigational clinical trials, setting mandatory compliance benchmarks for high-quality industrial development.
Enterprises shall adopt a registration-oriented mindset to systematically plan R&D roadmap at the initial development stage and arrange relevant preparations in advance, so as to align all R&D data with registration regulatory requirements.
For fundamental property research, a complete physicochemical test system shall be established at early R&D phase, covering key parameters including intrinsic viscosity, moisture content, melt flow rate, glass transition temperature, melting point, heavy metal content and residual monomer.
For raw material selection, PPDO with sufficient existing biocompatibility data shall be prioritized; available validated data such as registered PPDO master file can be cited to reduce redundant laboratory tests.
For degradation characterization, in-vivo degradation assessment is indispensable. Long-term degradation studies at predefined time points (1, 4, 12, 24 and 48 weeks) shall be arranged to collect data on degradation rate, degradation byproducts and post-degradation mechanical properties.
Test methodologies for core mechanical indicators including tensile strength, shear strength, flexural modulus, barb load resistance and breaking force shall be formulated during product development.
Long-term stability tests under simulated in-vivo environment are required to monitor mechanical deterioration and guarantee intact product function throughout intended service life.
Quantitative data shall be provided to verify the superior performance of proprietary structures such as fishbone barbs and double-needle configuration versus conventional designs, e.g. measured barb load resistance and breaking force, serving as evidence for structural innovation.
A full-set test schedule shall be finalized at early development. For long-term implantable devices (>30 days), a complete biocompatibility test panel is mandatory, consisting of cytotoxicity, skin sensitization, intracutaneous reactivity, pyrogen test, acute/subacute/chronic systemic toxicity, local tissue response after implantation, genotoxicity, carcinogenicity (if applicable) and hemocompatibility. Additional safety evaluation of degradation leachables with rigorous toxicological risk assessment shall be implemented.
Well-designed in-vivo animal studies simulating real clinical application shall be conducted to observe in-tissue performance, degradation progression and adjacent tissue reactions, generating predictive data to support subsequent clinical trials.
In accordance with the latest requirements specified in the Recommended Clinical Evaluation Pathways for Products in the Medical Device Classification Catalogue (2024 Supplement) issued by the CMDE, clinical trials are mandatorily required in principle for polydioxanone (PPDO) facial implant threads. Therefore, the overall clinical trial protocol shall be fully planned from the early R&D stage.
First, determine the basic sample size. The sample size shall be scientifically calculated based on the trial design type, comparison type, primary evaluation indicators and other core parameters. For instance, when taking the rate of grade-A wound healing as the primary evaluation indicator, a dropout rate of 5%–10% shall be incorporated into statistical calculation to confirm the minimum number of subjects required for each group.
Second, standardize the selection of research subjects. Clear and explicit inclusion and exclusion criteria must be formulated, such as healthy physical condition, subject age of 18 years old or above, and no administration of drugs affecting coagulation function within a short period, so as to ensure the representativeness and homogeneity of enrolled subjects.
Third, optimize other key protocol design elements. Long-term follow-up arrangements (5 years or even 10 years) are essential to comprehensively evaluate the long-term durability, safety and efficacy of the device after implantation.
Carry out preliminary communication with provincial drug administrations and CMDE to align R&D orientation with registration requirements and avoid unnecessary detours.
Select Grade A tertiary hospitals to conduct clinical trials with qualified hardware, professional research teams and independent ethical review capability.
Comply with ethical review requirements from early R&D phase, formulate appropriate informed consent forms and complete subject protection measures to prevent trial suspension caused by ethical defects.
Deploy Electronic Data Capture (EDC) system to guarantee tamper-proof and traceable clinical trial data.
Establish risk assessment framework at early development instead of delaying risk evaluation till registration stage; identify potential hazards and formulate corresponding preventive measures.
For domestic NMPA registration, refer to overseas regulatory frameworks including FDA regulations and EU MDR to pave the way for future global market access.
As an important product in the aesthetic medicine industry, the successful registration of polydioxanone (PPDO) facial implant threads relies on scientific planning and systematic verification initiated from the product R&D stage.
Manufacturers are recommended to engage registration experts in the early product design phase and establish a coordinated R&D-registration mechanism. This ensures full compliance with regulatory requirements throughout the entire product lifecycle from conceptual design to market launch, and effectively prevents registration failure caused by missing or non-compliant key data in the later stage. Meanwhile, professional teams can timely track and interpret the latest regulatory updates and international industry trends, making full use of policy incentives to accelerate the registration process.
Deda Medical provides full-process supporting services covering preliminary project judgment, research protocol design and registration dossier integration, specializing in medical device clinical evaluation, biocompatibility assessment, registration dossier compilation and quality system alignment.
Scientific supervision drives industrial development, and compliant innovation underpins the future. We work together to lead high-quality industrial progress with stringent standards and safeguard high-level innovative development with rigorous supervision, promoting the long-term and stable growth of China’s aesthetic medical device industry.
