When designing a medical device based on a resorbable polymer, an essential question arises early in the development process:
How long should the material remain present to fulfil the intended function of the device?
Resorption is more than a material property: it is a key design parameter. It should be considered alongside the required mechanical properties, device architecture and intended environment of use.
At Lattice Services, we offer a range of resorbable polymers that allow developers to explore different degradation timelines, including PDO, PLGA, PCL and PLCL.
Resorption as a dynamic design parameter
A resorbable medical device is designed to perform a function for a defined period before progressively degrading in the body. Depending on the intended application, it may provide temporary tissue support, maintain a structure, support a healing process or serve as a scaffold for tissue regeneration.
The challenge is to align the evolution of the material with the functional requirements of the device throughout its lifecycle.
Material selection therefore involves more than asking which polymer offers the greatest mechanical strength.
How long must the device retain the properties required to perform its intended function?
Answering this question helps guide material selection from the earliest stages of development.
Indicative resorption timelines for different polymers
The timelines below are indicative estimates only. They should not be interpreted as guaranteed in vivo resorption times. Actual behaviour depends on several factors, including polymer formulation, device geometry, manufacturing process and biological environment.
PDO – DIOXACTISSE 100
Indicative resorption timeframe: approximately 4–6 months
PDO (polydioxanone) is a resorbable polymer that may be considered for devices intended to perform a temporary function. Depending on the required properties and final design, it may be investigated for fibrous structures, sutures or selected tissue engineering applications.
Its suitability should be assessed in relation to the required support period and the evolution of its mechanical properties during degradation.
PLGA 85/15 – GLYCOLACTISSE 85/15
Indicative resorption timeframe: approximately 12–24 months
PLGA 85/15 (a copolymer of lactic acid and glycolic acid) may be investigated for devices requiring a more extended presence, without necessarily requiring persistence over several years.
Depending on its formulation and the design of the device, it may be of interest for tissue engineering applications and selected devices intended for bone regeneration.
Material selection should take into account the required functional lifetime, as well as changes in mechanical properties and degradation behaviour over time.
PCL – CAPROLACTISSE 100
Indicative resorption timeframe: generally more than 36 months
PCL (polycaprolactone) is generally characterised by slower degradation than many other resorbable polymers.
This longer timeframe may be relevant when a device needs to maintain its structure or selected mechanical properties over an extended period. PCL may be investigated for porous structures and scaffolds intended for tissue engineering.
The actual resorption timeframe nevertheless depends on the characteristics of the final device and the conditions in which it is used.
PLCL – CAPROGLYCOLACTISSE 70/30
Indicative resorption timeframe: approximately 12–24 months
PLCL (a copolymer of polycaprolactone and lactic acid) can combine flexibility, deformability and mechanical characteristics that may be suitable for applications requiring compliant structures.
These properties may be of interest for devices intended for soft tissues or exposed to dynamic mechanical loading, including selected tissue engineering applications.
PLCL behaviour depends on its composition, formulation and final device design. Its resorption timeframe should therefore be evaluated in the context of the intended application.
Resorption is not simply a countdown
An indicative timeframe for a base polymer is not sufficient, on its own, to predict how a finished device will behave.
Several factors can influence degradation kinetics and the evolution of mechanical properties:
- Device architecture and geometry: a solid component and a highly porous scaffold may behave differently.
- Material formulation and characteristics: polymer composition and initial properties influence how the material evolves.
- Manufacturing process: processing conditions, including those used in 3D printing, can affect the structure and properties of the finished component.
- Implantation site and biological environment: local conditions may influence material degradation.
- Mechanical loading: stresses applied to the device may affect its functional performance over time.
It is therefore essential to distinguish between the degradation timeframe of the material and the period during which the device retains the properties required for its intended function.
These two timelines are related, but they are not necessarily the same.
Designing around the device lifecycle
Three questions can help guide the selection of a resorbable polymer from the earliest stages of development.
1. What function must the device perform?
Is it intended to provide temporary mechanical support, act as a scaffold for tissue regeneration, serve as a barrier or fulfil another specific function?
2. For how long is this function required?
Must the device address a need lasting a few months, maintain its function for one to two years or support a longer-term process?
3. How should its properties evolve over time?
Should it retain its initial shape, progressively lose mechanical strength or gradually make way for regenerated tissue?
These questions help establish more relevant material selection criteria than the nominal resorption timeframe alone.
Polymer selection as a strategic design decision
Selecting a resorbable polymer is not simply a matter of choosing a raw material. It means defining how the device is intended to evolve over time.
The objective is not necessarily to select the material that persists the longest, but to identify the one whose behaviour best aligns with the intended function, mechanical requirements, device architecture and environment of use.
At Lattice Services, our resorbable filaments allow you to explore different design approaches and identify materials to evaluate against the requirements of your project.
Note: The resorption timeframes provided are indicative and for informational purposes only. They do not represent guaranteed performance for a finished device. Material selection and performance validation must be tailored to the intended application.
