Determination of tantalum from tantalum oxide nanoparticle X-ray/CT contrast agents in rat tissues and bodily fluids by ICP-OES

Adv Healthcare Materials

Chakravarty

et al. 2023

Longitudinal radiological monitoring of biomedical devices is increasingly important, driven by the risk of device failure following implantation. Polymeric devices are poorly visualized with clinical imaging, hampering efforts to use diagnostic imaging to predict failure and enable intervention. Introducing nanoparticle contrast agents into polymers is a potential method for creating radiopaque materials that can be monitored via computed tomography. However, the properties of composites may be altered with nanoparticle addition, jeopardizing device functionality. Thus, the material and biomechanical responses of model nanoparticle‐doped biomedical devices (phantoms), created from 0–40 wt% tantalum oxide (TaOx) nanoparticles in polycaprolactone and poly(lactide‐co‐glycolide) 85:15 and 50:50, representing non, slow, and fast degrading systems, respectively, are investigated. Phantoms degrade over 20 weeks in vitro in simulated physiological environments: healthy tissue (pH 7.4), inflammation (pH 6.5), and lysosomal conditions (pH 5.5), while radiopacity, structural stability, mechanical strength, and mass loss are monitored. The polymer matrix determines overall degradation kinetics, which increases with lower pH and higher TaOx content. Importantly, all radiopaque phantoms could be monitored for a full 20 weeks. Phantoms implanted in vivo and serially imaged demonstrate similar results. An optimal range of 5–20 wt% TaOx nanoparticles balances radiopacity requirements with implant properties, facilitating next‐generation biomedical devices.

Section: Resultsmentioning

confidence: 91%

Incorporating Tantalum Oxide Nanoparticles into Implantable Polymeric Biomedical Devices for Radiological Monitoring

Adv Healthcare Materials

Chakravarty

et al. 2023

“…They must diffuse to the blood, after which they can be excreted via liver, kidneys and spleen. [9,36] For nanoparticles, clearance has been shown to go rapidly from the blood, with less than 1.15% injected dose remaining in the body after 48 hrs. [9] Previous in vivo nanoparticle studies have not demonstrated any blurring of device features during sequential CT scans due to dispersed nanoparticles, so the results in long-term monitoring should be consistent with the data collected during in vivo applications.…”

Section: Longitudinal Monitoringmentioning

confidence: 99%

“…[9,36] For nanoparticles, clearance has been shown to go rapidly from the blood, with less than 1.15% injected dose remaining in the body after 48 hrs. [9] Previous in vivo nanoparticle studies have not demonstrated any blurring of device features during sequential CT scans due to dispersed nanoparticles, so the results in long-term monitoring should be consistent with the data collected during in vivo applications. [21] The incorporation of nanoparticles within slow degrading polymer matrices is a way to conveniently localize radiopaque markers or implants, bypassing the immediate problems with cellular toxicity of concentrated nanoparticle bolus injections and providing a sustained signal.…”

Section: Longitudinal Monitoringmentioning

confidence: 99%

“…[5,6] Introduction of radiopaque nanoparticles are an extremely versatile alternative. [7,8] Tantalum oxide (TaO x ) nanoparticles, in particular, are biocompatible in vivo with superior CT contrast over traditional iodinated compounds [9,10] , and can further be incorporated into polymeric matrices for use as biomaterials. [11,12] However, the incorporation of nanoparticles into polymeric devices requires study on the impact of materials properties that could alter device function, particularly as the percentage of nanoparticles increases.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Incorporating Radiopacity into Implantable Polymeric Biomedical Devices for Clinical Radiological Monitoring

Chakravarty

et al. 2023

Preprint

Longitudinal radiological monitoring of biomedical devices is increasingly important, driven by risk of device failure following implantation. Polymeric devices are poorly visualized with clinical imaging, hampering efforts to use diagnostic imaging to predict failure and enable intervention. Introducing nanoparticle contrast agents into polymers is a potential method for creating radiopaque materials that can be monitored via computed tomography. However, properties of composites may be altered with nanoparticle addition, jeopardizing device functionality. This, we investigated material and biomechanical response of model nanoparticle-doped biomedical devices (phantoms), created from 0-40wt% TaOx nanoparticles in polycaprolactone, poly(lactide-co-glycolide) 85:15 and 50:50, representing non-, slow and fast degrading systems, respectively. Phantoms degraded over 20 weeks in vitro, in simulated physiological environments: healthy tissue (pH 7.4), inflammation (pH 6.5), and lysosomal conditions (pH 5.5), while radiopacity, structural stability, mechanical strength and mass loss were monitored. The polymer matrix determined overall degradation kinetics, which increased with lower pH and higher TaOx content. Importantly, all radiopaque phantoms could be monitored for a full 20-weeks. Phantoms implanted in vivo and serially imaged, demonstrated similar results. An optimal range of 5-20wt% TaOx nanoparticles balanced radiopacity requirements with implant properties, facilitating next-generation biomedical devices.

“…Potential cytotoxicity concerns and fast excretion in native tissues have been raised for bismuth [11] and the highly water-soluble nature of barium sulfate (BaSO4), while commonly used as a clinical gastrointestinal contrast agent, presents hurdles in use with hydrophobic polymers. In contrast, tantalum oxide (TaO x ) nanoparticles are biocompatible and inert [12], and can be differentially synthesized to be compatible with either aqueous media or hydrophobic systems [13].…”

Section: Introductionmentioning

confidence: 99%

Radiopaque Implantable Biomaterials for Nerve Repair

Hix

Shapiro

2023

Preprint

Repairing peripheral nerve injuries remains a clinical challenge. To enhance nerve regeneration and functional recovery, the use of auxiliary implantable biomaterial conduits has become widespread. After implantation, there is currently no way to assess the location or function of polymeric biomedical devices, as they cannot be easily differentiated from surrounding tissue using clinical imaging modalities. Adding nanoparticle contrast agents into polymer matrices can introduce radiopacity and enable imaging using computed tomography (CT), but radiopacity must be balanced with changes in material properties that impact device function and biological response. In this study radiopacity was introduced to porous films of polycaprolactone (PCL) and poly(lactide-co-glycolide) (PLGA) 50:50 and 85:15 with 0-40wt% biocompatible tantalum oxide (TaOx) nanoparticles. To achieve radiopacity, at least 5wt% TaOx was required, with more than or equal to 20wt% TaOx leading to reduced mechanical properties and increased nano-scale surface roughness of films. As polymers used for peripheral nerve injury devices, films facilitated nerve regeneration in an in vitro co-culture model of glia (Schwann cells) and dorsal root ganglion neurons (DRG), measured by expression markers for myelination. The ability of radiopaque films to support nerve regeneration was determined by the properties of the polymer matrix, with a range of 5-20wt% TaOx balancing both imaging functionality with biological response and proving that in situ monitoring of nerve repair devices is feasible.