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Tropp, J.

Publications and source records attributed to Tropp, J..

2 recordsLinked to original sources

3D Tumor-Mimicking Phantom Models for Assessing NIR I/II Nanoparticles in Fluorescence-Guided Surgical Interventions

Fluorescence image-guided surgery (FIGS) offers high spatial resolution and real-time feedback but is limited by shallow tissue penetration and autofluorescence from current clinically approved fluorophores. The near-infrared (NIR) spectrum, specifically the NIR-I (700-900 nm) and NIR-II (950-1700 nm), addresses these limitations with deeper tissue penetration and improved signal-to-noise ratios. However, biological barriers and suboptimal optical performance under surgical conditions have hindered the clinical translation of NIR-I/II nanoprobes. In vivo mouse models have shown promise, but these models do not replicate the complex optical scenarios encountered during real-world surgeries. Existing tissue-mimicking phantoms used to evaluate NIR-I/II imaging systems are useful but fall short when assessing nanoprobes in surgical environments. These phantoms often fail to replicate the tumor microenvironment, limiting their predictive assessment. To overcome these challenges, we propose developing tumor-mimicking phantom models (TMPs) that integrate key tumor features, such as tunable tumor cell densities, in vivo-like nanoparticle concentrations, biologically relevant factors (pH, enzymes), replicate light absorption components (hemoglobin), and light scattering components (intralipid). These TMPs enable more clinically relevant assessments of NIR-I/II nanoprobes, including optical tissue penetration profiling, tumor margin delineation, and ex vivo thoracic surgery on porcine lungs. The components of TMPs can be further modulated to closely match the optical profiles of in vivo and ex vivo tumors. Additionally, 3D bioprinting technology facilitates a high-throughput platform for screening nanoprobes under realistic conditions. This approach will identify high-performing NIR-I/II probes with superior surgical utility, bridging the gap between preclinical findings and clinical applications, and ensuring results extend beyond traditional in vivo mouse studies. TOC O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=46 SRC="FIGDIR/small/636085v2_ufig1.gif" ALT="Figure 1"> View larger version (16K): org.highwire.dtl.DTLVardef@12b283aorg.highwire.dtl.DTLVardef@5e2dc7org.highwire.dtl.DTLVardef@10f6c36org.highwire.dtl.DTLVardef@189590d_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

Decellularized biohybrid nerve promotes motor axon projections

Developing nerve grafts with intact mesostructures, superior conductivity, minimal immunogenicity, and improved tissue integration is essential for the treatment and restoration of neurological dysfunctions. A key factor is promoting directed axon growth into the grafts. To achieve this, we developed biohybrid nerves using decellularized rat sciatic nerve modified by in situ polymerization of poly(3,4-ethylenedioxythiophene) (PEDOT). We compared nine biohybrid nerves with varying polymerization conditions and cycles, selecting the best candidate through material characterization. Our results showed that a 1:1 ratio of FeCl3 oxidant to ethylenedioxythiophene (EDOT) monomer, cycled twice, provided superior conductivity (>0.2 mS/cm), mechanical alignment, intact mesostructures, and high compatibility with cells and blood. To test the biohybrid nerves effectiveness in promoting motor axon growth, we used human Spinal Cord Spheroids (hSCSs) from HUES 3 Hb9:GFP cells, with motor axons labeled with green fluorescent protein (GFP). Seeding hSCS onto one end of the conduit allowed motor axon outgrowth into the biohybrid nerve. Our construct effectively promoted directed motor axon growth, which improved significantly after seeding the grafts with Schwann cells. This study presents a promising approach for reconstructing axonal tracts in humans.

bioengineering↗