Case Studies

Biomedical Analysis

Did Your Biocompatibility Study Fail? Trace Level Analysis to the Rescue A failed cytotoxicity test can raise red flags for medical device development. To pinpoint the culprit, analyze the test media from the failed test. By tracing the analysis back to the bill of materials (BOM) and processing aids,  the specific component responsible can often be identified. If the identified compound poses no toxicological risk in the intended application, this trace analysis can provide justification for releasing the product. 

Highly Crosslinked UHMWPE for Hip & Knee Arthoplasties A discovery by researchers at CPG and MGH led to the development of a new processing method for highly crosslinked UHMWPE that utilized mechanical deformation to reduce free radical concentration. This case study outlines the testing that demonstrated the efficacy of this technique. 

Oxidative Induction Time Measures Active Antioxidants CPG discovered a method of determining trace amounts of active antioxidant in oxidatively stabilized polyethylene.  Findings published in the Journal of Biomedical Materials Research.

Sniffing Out Biomarkers Using Chromatography: HS-GC-MS in Medical Device Development CPG used headspace solid-phase microextraction gas chromatography-mass spectrometry to generate unique, chromatographic fingerprints from the urine of cancer patients relative to biopsy-negative controls. Researchers from MIT and John Hopkins then used the HS SPME GC-MS information in combination with data from trained cancer detection dogs to train an artificial neural network (ANN) to emulate canine olfactory diagnostics. Findings published in PLOS ONE.


Annulus Fibrosus Tissue Model Leveraging strong hydrogel and custom test design expertise, CPG developed a composite structure that simplifies fatigue testing of nucleus pulposus replacements.

Synthetic Tissue Model for Bipolar and Monopolar Electrocautery Many hydrogel tissue models still lack some of the specific behaviors observed in natural tissue. In this case study, CPG develops a hydrogel formulation that emulates tissue charring, crucial for adequate surgical training and product design.

Synthetic Tissue Models for Medical Device Development. Includes example of hydrogel arterial model stiffened to match the compliance of human aortas. The use of synthetic materials to replace tissues enables the ability to test over substantially extended periods without concern for natural variability or tissue degradation.

Tissue Bulking with Injectable Hydrogels CPG developed a permanent, non-migrating, biocompatible material suitable for percutaneous injection. In collaboration with the Massachusetts General Hospital, this hydrogel has been used to treat mitral valve regurgitation in an ovine model. Additionally, CPG has investigated the use of this formulation for urinary incontinence and gastroesophageal reflux disease (GERD). Findings published in the JACC: Cardiovascular Interventions.

Root-Cause and Failure Analysis

Artificial Lens Hazing Root Cause Analysis A client of Cambridge Polymer Group had concerns over hazing that was occurring in a new formulation of lenses during manufacture. CPG traced the cause of the cloudiness to a poorly controlled reaction process resulting in microcavitation within the lens during the swelling process as the lens hydrated.

Cleanliness Assessment of Medical Devices  This case highlights how changes in manufacturing processes can impact biocompatibility.

Failure Analysis in Catheters A client presented catheter hubs that appeared to be cracking during their manufacturing process. Cambridge Polymer Group isolated the root cause and proposed an alternative manufacturing strategy that the client adopted.

Root Cause Analysis in Cracked Polycarbonate Syringes A client requested a root cause analysis of cracks and haziness that appeared in polycarbonate (PC) syringes during accelerated aging as part of a shelf-storage study. The results of the study were unexpected and revealed a few issues with the manufacturing line.

Root Cause Analysis of Color Change in Aqueous Drug Product An aqueous drug product failed inspection due to discolorations of both the drug solution and the vial wall. CPG identified the cause of the discolorations using microscopy and elemental analysis, enabling release of the production hold on the drug product.