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Did you know Poly-Med, Inc. Provides Analytical Services?

At Poly-Med, analytical testing has been and continues to be a cornerstone of our key technological advancements in bioresorbable materials. In our formative years, our early developmental work utilized a vast array of in-house testing equipment to characterize, refine, and create our extensive polymer suite. As an added benefit of our years of growth and accumulation of laboratory skills and equipment, we can offer our extensive analytical capabilities to you – our clients – to support the development of your medical device and pharmaceutical products.

In polymer science, it is important to assess the structural integrity at different processing steps via inherent viscosity (IV) measurements. This information provides insight to the extent of degradation in a polymer, and can give a snapshot of the overall state of the material. Additionally, our polymers can be characterized using difference scanning calorimetry to determine key material characteristics like glass transition and melt temperatures. Our capabilities also include both gas chromatography (GC) and gel permeation chromatography (GPC) to determine residuals, polydispersity, and other molecular attributes.

We frequently extend these services to our clients both within, and independently of, our design and development projects. Poly-Med aims to be a trusted long-term partner for your product’s development – and that includes analytical testing needs. To meet the specific needs of our clients, analysis can be performed on an as-requested basis, or as part of release testing. We perform analysis according to consensus standards and develop custom test methods as needed. Customers benefit from our broad capabilities, fast turn-around time, and quality of service. Visit our analytics page at www.poly-med.com/services/analytical-services/ to see our full service offerings. Contact us at sales@poly-med.com for specific questions about our services or the development of testing protocols.

James Turner, Ph.D.

Electrospinning for Bioresorbable Medical Devices

Electrospinning is a fiber production method which uses electric force to draw charged threads of a polymer solution or melt into fibers with diameters in the nano to micron size-scale. While this sounds like science fiction, it is a process that dates back to the early 20th century and continues to be at the forefront of biomedical engineering today. To date, pioneering research and development projects continue to validate its immense potential. In the biomedical and biomaterials communities alone, electrospinning has been widely utilized in disciplines such as: regenerative medicine (i.e., vascular, tendon/ligament, cardiac, neural, and wound healing), nanomedicine/drug delivery, cancer therapy, dentistry, and biosensors.

The set-up is simple and straightforward and includes three (3) main components:

1. Spinneret: A pump/polymer feed that distributes a polymer solution/melt at a controlled flow rate

2. High voltage source: Electrical force is applied to the spinneret, which accelerates the polymer solution as a jet from the spinneret tip to the collecting target

3. Collecting target: Accumulation area for fibers to build a fibrous construct, it can be designed for various applications and fiber orientation specifications (i.e., drum, blade collector, metallic plate, and array of parallel or counter electrodes)

Electrospinning yields fibers with remarkable properties. The resulting fibers are continuous, can be produced to submicron architectures, and exhibit high surface area-to-volume ratios and inter-/intra porosity. The electrospinning technique also allows for control over mechanical properties, microstructure, degradation rates, and downstream cellular and tissue level responses. Combining these benefits with the advantages of bioresorbable materials and devices can yield remarkable improvements in modern medicine which include:

• Eliminating the need for invasive secondary surgery intervention since the bioresorbable polymer is metabolized via physiological biochemical pathways

• Providing porous, supportive scaffolding for cell guidance, migration, and development until natural tissue replaces the implant/device

• Imitating structural tissue complexity by being able to build structures from the nano, micro, and macro-scale

Poly-Med, a world leader in bioresorbable polymers, has utilized electrospinning to develop bioresorbable scaffolds and devices for improved tissue regeneration, restoration, and function. Poly-Med has the ability to provide industrial scale electrospinning services for a range of bioresorbable polymers that meet not only mechanical and degradation requirements but are also viable in the human body.

It is exciting to be a part of Poly-Med’s continued growth in the electrospinning field. This revolutionary technique carries great promise for advancing not only the field of biomedical engineering but also improving human lives and expanding upon traditional mesh based technologies. If you are interested in hearing more about our electrospinning capabilities or have an idea for an electrospun component or device, please reach out to us!

Brittany Banik, Ph.D.

Technical Textile Insights: Warp vs. Weft Knitting

Vertical integration at Poly-Med allows us to utilize our own unique materials for a vast array of downstream processing. We use bioresorbable polymers made in-house every day for custom applications in 3D printing, fiber extrusion, electrospinning, and more! This allows us to efficiently move a unique material from raw material processing into a fully formed device component. This vertical integration gives us a unique advantage in the medical textile industry, as we are able to manufacture custom, medical-grade textiles from raw materials to final products under one roof.

Of the many ways to produce textile products suitable for medical devices, Warp Knitting and Weft (Circular) Knitting are some of the most commonly used in medical and other textile industries, including extensive use in the apparel industry. Each method offers unique benefits and final properties, so choosing the correct one for a specific medical application can be critical! At Poly-Med, we can help you decide which production method best suits your specific application.

Weft (Circular) Knitting requires only a single yarn feed and produces a very simple stitch so that the created stitches interlock the yarn with itself. The result is a tubular knit fabric with very high flexibility and stretch. The single yarn input allows for production of very thin fabrics at a variety of fabric widths. For unique applications, the production of a tubular fabric can even allow for 3D constructs with minimal or no seams. One of the main benefits to weft knitting is cost. This knitting method only requires the single yarn feed, so trial runs can be conducted with minimal material input requirements and fewer processing steps to get started. Weft Knitting can be used to produce very narrow fabrics, further reducing costs to trial out unique materials or applications. Processing times are generally short and are easily scaled between short, one-off trials and mass production.

Warp Knitting allows for many more customizations to the fabric materials and properties. Unlike the single yarn feed used in Weft Knitting, Warp Knitting requires individual ends to feed in across the entire width of the fabric. This requires some additional work to prepare the material for knitting, but offers more options for a custom fabric. Striping can be incorporated along the length of the fabric by mixing materials and the stitching pattern can be fully customized for each yarn input end. Unique combinations of materials and stitching patterns allow for very custom fabrics designed to meet specific attributes and mechanical properties. The resulting material is often more dimensionally stable and less prone to runs than weft-knit products.

Weft Knitting and Warp Knitting represent only a couple of the capabilities at Poly-Med to produce unique medical device components using bioresorbable polymers. If you are working on a medical device and are interesting in learning more about degradable polymers and how to process them, Contact US to learn how we can advance your idea.

Andrew Hargett, M.S.

The PMI Perspective: Independent Evaluation of Poly-Med’s Bioresorbable Medical Grade 3D Printing Filaments

Poly-Med has recently been in collaboration with Queensland University of Technology to promote research of our unique, bioresorbable medical grade 3D printing filaments. The latest publication, authored by Mina Mohseni, Professor Dietmar Hutmacher, and Dr. Nathan Castro, highlights performance of these filaments in fused filament fabrication (FFF) additive manufactured (AM) tissue scaffolding. Specifically, this research sought to characterize material properties and evaluate potential use in both hard and soft tissue engineering applications.

As Mohseni et al. notes, additive manufacturing has established itself as an advantageous method for fabrication of unique and physiologically relevant structures to support tissue growth. Equally important in selecting the correct scaffolding structure, choosing the appropriate material is also vital for successful tissue ingrowth. Currently, Poly-Med offers four medical grade filaments for 3D printing: Lactoprene® 100M, Max-Prene® 955, Dioxaprene® 100M, and Caproprene™ 100M. The bioresorbable nature of these filaments make them ideal candidates for tissue scaffolding applications and use in regenerative medicine.

Through extensive physiochemical analysis of these four filaments, Mohseni et al. concludes that all filaments are viable options for tissue scaffolding, with each material having unique properties to fit a range of soft and hard tissue applications. For example, it was noted that Dioxaprene® 100M exhibits softness and flexibility, making it an ideal choice for soft tissue engineering. Caproprene™ 100M displays similar mechanical properties as those of Dioxaprene® 100M, however Caproprene™ 100M strength and mass loss occurs over a much longer time frame. Thus, while Dioxaprene® 100M and Caproprene™ 100M are both soft tissue-oriented, either can be selected depending on the desired degradation timeline.

For hard tissue applications, materials with a higher stiffness are often preferred. To this effect, Poly-Med offers Max-Prene® 955 and Lactoprene® 100M, which both exhibit an elastic modulus suitable for hard tissue regeneration, with values in the range of 63-89 MPa. In fact, elastic modulus and other mechanical properties of these materials can be tuned by adjusting scaffold pore size, % infill, which Mohseni et al. further details in the article.

Poly-Med offers four unique bioresorbable filaments for 3D printing, each with its own niche and range of potential applications. Mohseni et al. has provided an extensive review of the physiochemical properties of these filaments that can help guide any device manufacturer in the right direction when determining which material is best for a given product. As always, feel free to contact Poly-Med for assistance with any aspect of additive manufacturing – we are here to be a creative partner as you bring your solution to market. Contact us for more information regarding our bioresorbable 3D printing filaments.

Brad Johns, M.S.

To see the original Queensland University of Technology evaluation: http://www.mdpi.com/2073-4360/10/1

FDA Guidance on Additive Manufacturing Devices: The Poly-Med Perspective

After publishing a draft guidance document for additive manufacturing medical devices in 2016, the FDA issued its highly anticipated Technical Considerations for Additive Manufactured Medical Devices in December 2017. The latest volume on 3D-printed devices focuses heavily on advising manufacturers on 3D-printing-specific focus areas to consider when developing a new additive manufactured device.

The guidance document is divided into two primary sections: device design/manufacturing and testing. The former section outlines general steps that must be taken in the development process. To begin the general flow of additive manufacturing device design, a computer model must first be created. This part file can be generated using any of a number of 3D-modeling software. In cases where a patient-matched device is being fabricated, additional software may be required to convert scans of patient anatomy into a viable model file. Next, the model is converted into a part file which actually allows for printing. The part file communicates to the printer how the design will be assembled. Using the appropriate equipment, the part is then printed according to the printer software inputs and part file assembly instructions. Some parts may then be post-processed to remove residues or any other printing defects from the part.

The guidance document also speaks to the importance of using quality materials in the additive manufacturing process. Poly-Med recognizes material selection as being critical to device success. PMI specializes in production of traceable, medical-grade filaments, which are ideal for medical device design and manufacturing in the 3D-printing space. Further, choosing the appropriate material for a given application is also crucial. As the device designer, it is of the utmost importance to consider mechanical properties (stiffness, strength, etc.) as well as degradation time frames for bioresorbable products. Poly-Med offers a wide array of materials with numerous combinations of mechanical properties and degradation times to fit almost any application.

As a source of experienced medical device and component design, Poly-Med is committed to adhering to the new guidance document and providing expertise in development of 3D-printed medical devices. PMI is already in collaboration with a number of clients who are committed to additive manufactured products at various stages of device design.

If you are working on a medical device application and are interested in learning more about our additive manufacturing capabilities with bioresorbable polymers, Contact Us to learn how we can advance your idea.

Brad Johns, M.S.

Beyond the Product: The Importance of Packaging Design

As we come out of the busiest season for every postal worker and mailman, we are reminded of how little thought often goes into the shipping and packaging of all the gifts and products being transported. It can be hard enough for the manufacturer to ship your online order to meet the gift’s deadline for arrival, so considering how the packaging affects the final result might be an unaffordable luxury. A set of fine china placed into a cardboard box with no bubble wrap might result in a pile of fine chips when thrown onto a delivery vehicle. Your family’s secret fruitcake recipe might arrive as a fruit-pancake after having your neighbor’s new weight set stacked on top of it at the warehouse while awaiting delivery.

When we take the same look at the medical device field, many of the same concerns apply. Your newly developed medical device, sure to make a big market splash as the ideal blend of form and function, is only as good as the condition it arrives in to the end user. Additional design work is required to ensure that the form isn’t crushed and the function isn’t lost from poor transport conditions. Just like the piece of delicate china, care must be taken to ensure compressive forces, drops, constant vibrations, temperature fluctuations, and pressurized chambers don’t tamper with your perfect design in transit.

When it comes to medical devices, several other considerations must take place. Most notably, shipping offers the ultimate test to the sterile barrier of your device. Even when the device itself is sturdy and resilient, a puncture to the packaging or a leak in a seal could render the device just as useless and more dangerous to the end user than a shattered component. Unlike opening a squished fruitcake, defects to sterile barriers might not be as obvious.

At Poly-Med, our devices, components, and materials offer an additional packaging challenge. We produce a wide variety of biodegradable polymers which break down by bulk hydrolytic degradation. The very sensitivity to moisture that allows for novel applications such as timed pharmaceutical release, temporary structural strength, and reductions in device removal surgeries also requires that we consider packaging a main concern. When designing the packaging for our products, we must utilize materials which offer moisture, bioburden, and UV barriers in addition to the structural support required by other device types. Most often, this requires our packaging and materials to be thoroughly dried prior to shipment in order to extend the product shelf-life to its maximum potential. We also run extensive validation efforts on every aspect of the packaging design, where a small channel in the seal or puncture in a pouch is unacceptable. With the added design work and validation runs, we take the extra forethought and effort to ensure that products arrive just as they were designed, no matter how loaded the delivery truck is.

If you are working on a medical device application and are interested in learning more about degradable polymers and how to successfully package them, Contact US to learn how we can advance your idea.

Andrew Hargett, M.S.

2018 marks 25th Anniversary at Poly-Med

In 2018, Poly-Med will celebrate its 25th anniversary. My father, our founder, Dr. Shalaby Shalaby is considered one of the forefathers in the bioresorbable polymer industry. In the late 1970’s he led an exploratory group on polymers for biomedical applications at a large medical device company. During that time, he was one the lead inventors for several bioresorbable products including the Vicryl® suture.

In 1990, his love for research and education brought him to Clemson University in South Carolina. In the summer of 1993, Dr. Shalaby founded the company as a means to continue unfettered research in the bioresorbable polymer industry and to teach and sponsor students. He and a handful of PhD students started working out of a Clemson incubator building. This was a time for a lot of personal and professional growth as everyone was learning new things and pitching in to help where needed. During these early years, the focus was on research and education.

From the very beginning, Dr. Shalaby encouraged his employees to continue education in pursuit of creativity. We continue this emphasis with over 30 graduate thesis earned through a partnership with Clemson University and Poly-Med. Today, Poly-Med’s influence reaches beyond the classroom. We’ve grown to over 85 employees and work with some of the largest medical device companies in the world.

As we evolve as a company, my father’s work is at the heart of what we do. His hundreds of patents allow us to provide creative solutions to medical device companies as they work on novel devices to improve patient lives. Through continual improvement by personal and professional growth, our employees are excited to make an impact on the medtech industry. I’d like to think my father would be proud to see how far we’ve come as a company and that the foundation he built continues to support us 25 years later and beyond.

Dave Shalaby
President, Poly-Med, Inc.

How do bioresorbable polymers degrade?

Poly-Med’s bioresorbable polymers offer customized product solutions when an implant does not need to permanently remain in the body. The key trait for our materials is that they degrade within a physiological environment. Often times, this can be misconstrued to be a variety of degradation mechanisms including surface erosion, bulk erosion, among others.

Surface erosion takes place when mass loss for a device occurs at the water/implant interface, causing the implant to resorb from its outer surface toward its center while maintaining its bulk integrity. This is sometimes referred to as ‘device thinning’.

The majority of Poly-Med’s polymers degrade by a process known as bulk erosion. Bulk erosion occurs when the main mechanism for degradation is by the diffusion of water into the device or polymer structure, leading to hydrolysis. For bulk degradation, polymer properties are generally affected first by a decrease in molecular weight, followed by a decrease in strength, and finally, a decrease in mass.

By having a staggered rate of degradation for different polymer properties, it is extremely important to perform in vitro characterization of your product to truly understand the time scale for degradation and the appreciable loss of properties.
If you are working on a medical device application, and are interested in learning more about our bulk eroding polymers, Contact Me to learn how we can advance your idea.

Seth McCullen, Ph.D. Manager, Business Development