Technical Challenges Associated with Bioabsorbable Materials for Vascular Stents


Technical Challenges Associated with Bioabsorbable Materials for Vascular Stents

Joseph Berglund, Ph.D.
Principal R&D Engineer
Medtronic CardioVascular


Vascular stents are tiny mesh-like structures intended to prop open blood vessels and prevent abrupt reclosures following angioplasty procedures. Worldwide, bare metal stents (BMS) and drug eluting stents (DES), designed to reduce post-procedural restenosis, constitute a $5+ billion market. Once an artery has healed, however, stents are no longer thought to serve a functional role. Consequently, bioabsorbable stents would be preferred to permanent implants as they would terminate the need for anti-platelet therapy, provide opportunity for reintervention, and return arteries to a more physiological and natural state. While a number of groups have initiated clinical trials evaluating bioabsorbable technologies, the technical challenges to develop and commercialize a successful product remains very high. Material properties of bioabsorbable polymers are very different from stainless and cobalt-chromium alloys typically used in stent design. Also, the potential of complications that may result via the process degradation poses additional risks long after the intervention has been performed. Material selection and processing will be paramount to appropriately balance the potential benefits of absorption with the unmet needs. This presentation highlights some technical challenges associated with bioabsorbable polymers in the context of experiences from Medtronic’s bioabsorbable stent program. Balancing material properties including acute and chronic mechanical properties, degradation time, and biocompatibility with uncompromised product deliverability, efficacy, and safety is discussed. It is imperative to understand the influence of material properties on stent design; the role of FDA regulatory requirements on development paths; and the clinical need attempting to be addressed, when designing a bioabsorbable product.


Speaker Background

Joe Berglund first started working with polymers as an undergrad research assistant at Johns Hopkins University where he majored in biomedical engineering with a focus on materials science & engineering. Joe then moved to Atlanta, GA to continue graduate training at the Georgia Institute of Technology. There he extended many of the principles that dictate polymer behaviors to natural tissues as part of his research on tissue engineered blood vessels for by-pass surgical grafts and the contributions of collagen, elastin, and other extracellular matrix proteins on the mechanical properties of the constructs. Joe received his Ph.D. in 2002 and went on to perform an American Heart Association postdoctoral fellowship at the Emory School of Medicine where he studied the effects of shear stresses from normal and disturbed blood flow on the function of arterial endothelial cells. Joe worked briefly at Ethicon-J&J where he synthesized and characterized new families of elastomeric bioabsorbable copolymers before moving to Santa Rosa, CA to join Medtronic CardioVascular. There he works on early pipeline projects as an R&D engineer in the Science and Technology department. His primary projects focus on developing and evaluating bioabsorbable technologies as vascular devices and next generation drug eluting stent candidates. When he is not working, Joe enjoys cycling, swimming, and camping. Recently, Joe has tried to pick-up surfing, but he is starting to reconsider whether or not the cold water agrees with him.



Thursday, August 13


Michael's Restaurant at Shoreline Park
2960 N Shoreline Blvd
Mountain View, CA  94043
Directions  Map


6 PM social hour
7 PM dinner
8 PM lecture





Early Registration - Up to 7 days in advance of deadline



Registration - Up to deadline



After deadline/walk-in (Availability NOT guaranteed)



Lecture-only is free.



We accept cash or checks, but are unable to accept payment by credit card at this time. Payment is taken at the door.  No-shows are responsible for full payment of registration fee.


Please register on the web page or contact:
Lothar Kleiner

email: lothar.kleiner -at-

Deadline for registration:

5PM, Thursday August 6 for early registration discount
5PM, Wednesday August 12 for registration (or until venue has reached capacity.)

Dinner Selections:

Salmon filet with beurre blanc
Chicken Marsala
Mushroom crepes

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