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Holiday Hours

Please note that our lab will be closed on the following dates to allow our team to enjoy the holidays:

• December 24 - 25 (Christmas Eve & Day)
• December 31 - January 1 (New Year's Eve & Day)

We will resume normal business hours on January 2nd, ready to tackle your new materials challenges in the coming year.

If you have any questions or need assistance on existing quotes or projects, feel free to reach out by email or contacting us at 617-629-4400.

Additionally, if you have any new consulting or testing needs, we would be happy to discuss how we can assist you.

We are truly grateful for your partnership and look forward to providing you with game-changing material science consulting and testing in 2025 and beyond.

Warmly,

The Cambridge Polymer Group Team

ASTM recently published a new version of F2459 "Standard Test Method for Extracting Residue from Medical Components and Quantifying via Gravimetric Analysis.” This updated standard expands its scope beyond metallic implants to include ceramic and polymeric medical devices.

Key Updates and Applications

• Expanded Scope: The standard now covers residue assessment for metallic, ceramic, and polymeric medical devices.
• Cleanliness Assessment: It serves as a high-level evaluation method for medical device cleanliness.
• Additive Manufacturing: The standard provides a basis for preparing extracts for particulate residue assessment in additive manufacturing standards.
• FDA Recognition: The FDA recognizes this standard for quality assessment of medical device manufacturing facilities.

Significance and Contributions

• The standard identifies two techniques to quantify extractable residue on medical components.
• It allows investigators to compare relative levels of component cleanliness.
• The method's applicability has been demonstrated through numerous literature reports.

Impact on the Medical Device Industry

The expansion of ASTM F2459 to include ceramic and polymeric medical devices is a significant development for the industry. As medical technology advances, the materials used in device manufacturing have diversified, necessitating more comprehensive testing methods. This update ensures that a wider range of medical devices can be assessed for cleanliness using a standardized approach. 

Benefits for Manufacturers

1. Consistency: Provides a uniform method for cleanliness assessment across different material types.
2. Quality Assurance: Helps manufacturers maintain high standards of cleanliness in their production processes.
3. Regulatory Compliance: Aligns with FDA expectations, potentially streamlining the approval process.

Implications for Patient Safety

The enhanced standard contributes to patient safety by:

• Ensuring more thorough cleanliness assessments for a broader range of medical devices.
• Reducing the risk of contamination-related complications in patients.
• Promoting confidence in the safety and quality of medical devices.

The Role of Gravimetric Analysis

Gravimetric analysis, the core technique in ASTM F2459, involves precise weighing of residues extracted from medical components. This method:

• Provides quantitative data on the amount of extractable residue.
• Is highly sensitive, capable of detecting minute amounts of contaminants.
• Offers reproducible results, crucial for quality control and regulatory compliance.

Future Directions

As the medical device industry continues to evolve, particularly with the rise of additive manufacturing and novel biomaterials, standards like ASTM F2459 will likely undergo further changes. Areas of potential future development include:

• Integration with other analytical techniques for more comprehensive residue characterization.
• Adaptation to emerging manufacturing technologies and materials.
• Enhanced protocols for specific types of medical devices or materials.

Scientists from Cambridge Polymer Group contributed to the revisions of this standard and regularly conduct this test. Our involvement underscores the collaborative nature of standards development, bringing together expertise from industry, academia, and regulatory bodies.

This update reflects the evolving needs of the medical device industry, particularly in light of new manufacturing technologies like additive manufacturing. As the industry continues to innovate, the importance of robust, adaptable standards like ASTM F2459 becomes increasingly critical in ensuring the safety and efficacy of medical devices.

Polymer deformulation typically involves multiple tests to identify the type of polymer, assess the presence of potential blended polymers, and evaluate the incorporation of additives such as colorants, stabilizers, and processing aids. An elegant and more rapid alternative involves a form of pyrolysis gas chromatography mass spectrometry.

During pyrolysis, polymeric materials are rapidly heated to above their thermal decomposition temperatures such that covalent bonds are broken and rearranged. The resultant smaller fragments (pyrolyzates) are then separated using gas chromatography-mass spectrometry (GC-MS). Through identification of the pyrolyzates, the original polymer can be identified.

Challenges in Polymer Identification

Often, the pyrogram of a pyrolyzed polymeric material will contain peaks that do not originate from the polymer itself but instead can be traced back to:

• Volatile or semi-volatile residual solvents
• Monomers
• Contaminants
• Additives

These additional peaks can make accurate identification of the base resin more challenging and, likewise, identification of these peaks can be complicated by interference from the pyrolyzates. Although these compounds can be removed by an extraction process prior to pyrolysis GC-MS to separately characterize the volatile/semi-volatile compounds and identify the polymer, this approach can be unnecessarily burdensome.

Multi-Step Pyrolysis GC-MS

As an alternative approach towards characterization of both additives and the base resin, polymers can be subjected to multi-step pyrolysis GC-MS. Materials are initially heated to a temperature below the thermal decomposition temperature that allows for volatile and semi-volatile compounds to be thermally desorbed prior to pyrolysis. These compounds can then be identified and evaluated separately from the pyrolyzates of the base resin. The identity of the base resin can then be determined by heating the same sample to a temperature above the decomposition temperature. In sum, multi-step pyrolysis GC-MS can be used to evaluate the additive package and base resin of a polymeric material with only a small sample and no preparation beyond transferring the material to a quartz pyrolysis tube.

As an example of the utility of multi-step pyrolysis GC-MS, polypropylene often contains antistatic agents, slip agents, sterically hindered phenol antioxidants, and UV-absorbers. These compounds could potentially be obscured by the pyrogram that is typically associated with polypropylene pyrolysis. However, by using the multi-step approach, many of the contaminants, antioxidants, and UV-absorbers can be identified prior to pyrolysis. As shown below, thermal desorption of polypropylene at 350 °C yielded a sterically hindered phenol antioxidant, as well as a hexaethylene glycol, which likely is a functional group of a higher molecular weight slip additive. Pyrolysis of the same sample at 800 °C yielded a pattern of 1-alkenes consistent with polypropylene.  

On November 6, 2024, the FDA held a workshop to discuss the potential expansion of the Accreditation Scheme for Conformity Assessment (ASCA) program to include chemical characterization per ISO 10993-18. This expansion would build upon the current ASCA program, which primarily covers select biological endpoint tests according to ISO 10993. Because the FDA has already reviewed and approved the test methods by accredited laboratories, the ASCA program is intended to reduce additional information (AI) requests and FDA reviewer time.

Morning Session

• Industry stakeholders spoke about extractables and leachables (E/L) testing approaches.
• Discussion focused on proficiency testing and the coverage map provided by surrogate compounds.
• FDA shared results from a recent round robin E/L study involving eight laboratories.

Afternoon Session

• Focused on the potential scope of an expanded ASCA program.
• Outlined proposed accreditation process for laboratories.

Proposed ASCA Accreditation Process

1. External accreditation to ISO 10993-18, such as ISO 17025
2. Submission of E/L testing protocols to FDA, including:

• Extraction procedures
• Equipment setup and verification
• Sample testing
• Data analysis

3. Provision of personnel training evidence

If the FDA accredits a laboratory, reports can be summaries of procedures and results, with less FDA scrutiny. Challenging devices (e.g., hydrogels, degradables) that may require unique testing methods would fall outside of the ASCA accreditation program.

Key Discussion Points

The FDA sought input on various aspects of ISO 10993-18 testing, including:

• Test article preparation methods
• Use of response factor databases
• Selection of surrogate compounds for semi-quantitation
• Identification confidence criteria

Attendees, including Dr. Becky Bader and Dr. Stephen Spiegelberg from Cambridge Polymer Group, participated in the Q&A session and plan to provide additional written feedback.

Next Steps

The FDA will review workshop discussions and subsequent written feedback as they consider the potential expansion of the ASCA program. The agency will post responses to the questions raised during the workshop as they continue to evaluate this expansion.

This workshop represents another step in the ongoing dialogue between the FDA and industry stakeholders regarding chemical characterization testing for medical devices. The potential expansion of the ASCA program could have significant implications for both testing laboratories and device manufacturers.

At Cambridge Polymer Group, we are constantly pushing the boundaries of polymer science to develop innovative solutions for our clients. Our recent advancement in hydrogel technology aims to enhance surgical training by offering realistic tissue phantoms that more closely mimic the behavior of human tissue during electrosurgical procedures.

The Challenge: Realistic Tissue Simulation

As the medical device industry moves away from animal and cadaveric testing, there is a growing need for synthetic tissue models that can replicate the nuanced responses of human organs. While many commercially available phantoms may look realistic, they often fall short in simulating crucial aspects of tissue behavior during surgical interventions.

One of our clients approached us with a specific challenge: developing a synthetic tissue phantom that could char and smoke realistically during electrosurgical procedures, just like natural tissue. This behavior is critical for effective surgical training, especially when using high-energy intervention devices like electrocautery or radiofrequency ablation tools.

Our Solution: The "e-tissue" Hydrogel

Drawing inspiration from the Maillard reaction, the chemical process responsible for food browning, Research Scientist Joseph White and his CPG team developed a novel "e-tissue" hydrogel formulation. This innovative material not only provides a realistic tactile feel but also responds to electrical energy in a manner consistent with natural tissue.

Key features of our e-tissue hydrogel:

• Chars and produces smoke under bipolar and monopolar electrosurgical intervention
• Cuts realistically during electrosurgical procedures
• Offers appropriate electrical conductivity and thermal decomposition properties
• Provides a tactile feel similar to natural tissue

Putting e-tissue to the Test

To demonstrate the effectiveness of our e-tissue hydrogel, we conducted comparative tests using chicken heart tissue (a common surrogate for human tissue in surgical training) and our synthetic models. The results were notable:

• Both translucent and red-colored e-tissue options produced char and smoke during bipolar electrocautery, closely mimicking the behavior of the chicken heart tissue.
• When cast into specific anatomical shapes (such as a papilla), the e-tissue model charred and smoked realistically under monopolar electrocautery during simulated sphincterotomy training.

Implications for Surgical Training and Medical Device Development

Our e-tissue hydrogel opens new possibilities for surgical training and medical device testing:

1. Enhanced realism: Trainees can experience tissue responses that closely match real-life scenarios, improving the quality of their training.
2. Ethical considerations: Reduced reliance on animal and cadaveric tissue for training and testing.
3. Consistency and repeatability: Unlike natural tissue with its short shelf life, our synthetic models offer stable and consistent properties for repeated use.
4. Customization potential: The hydrogel can be tailored to mimic specific tissue types or anatomical structures.

The Future of Synthetic Tissue Models

At Cambridge Polymer Group, we are committed to advancing the field of synthetic tissue modeling. Our expertise in hydrogel chemistry, materials science, and custom test design positions us uniquely to develop application-specific tissue phantoms for a wide range of medical applications.

Whether you are looking to create surgical training tools, test beds for new medical devices, or marketing demonstrators, our team is ready to help you bring your vision to life. Contact us today to learn more about how our custom tissue model services can benefit your organization.

California, known for its progressive stance on environmental and health issues, is once again at the forefront of regulatory change. On September 25, 2024, California Governor Gavin Newsom signed the Toxic-Free Medical Devices Act (AB 2300) into law. The legislation prohibits the use of certain ortho-phthalates, specifically di-(2-ethylhexyl) phthalate (DEHP), in intravenous (IV) solution containers and tubing products. 

What Are Phthalates? 

Phthalates are a group of chemicals used to make plastics, primarily polyvinyl chloride (PVC),more flexible and durable. These additives are commonly found in various medical products, including medical devices such as IV bags, tubing, and catheters. They have also been used more broadly in industries ranging from toys to tools, although legislation is generally already in place outside of medical devices. In some cases, these compounds can be present at greater than 30% of the mass of the material.  

Toxic Free Medical Devices Act – California AB 2300  

Implications for the Medical Device Industry 

Regulatory Compliance