Bridget M. Crawford

Folate Receptor-Targeted Theranostic Nanoconstruct for Surface-Enhanced Raman Scattering Imaging and Photodynamic Therapy

We report the synthesis of a folate receptor (FR)-targeted theranostic nanocomposite for surface-enhanced Raman scattering (SERS) imaging and photodynamic therapy (PDT). FR-specific SERS detection and PDT are demonstrated in vitro using two FR-positive cancer cell lines and one FR-negative cancer cell lines.

Human Adipose-Derived Stem Cells Labeled with Plasmonic Gold Nanostars for Cellular Tracking and Photothermal Cancer Cell Ablation.

Background: Gold nanostars are unique nanoplatforms that can be imaged in real time and transform light energy into heat to ablate cells. Adipose-derived stem cells migrate toward tumor niches in response to chemokines. The ability of adipose-derived stem cells to migrate and integrate into tumors makes them ideal vehicles for the targeted delivery of cancer nanotherapeutics. Methods: To test the labeling efficiency of gold nanostars, undifferentiated adipose-derived stem cells were incubated with gold nanostars and a commercially available nanoparticle (Qtracker), then imaged using two-photon photoluminescence microscopy. The effects of gold nanostars on cell phenotype, proliferation, and viability were assessed with flow cytometry, 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide metabolic assay, and trypan blue, respectively. Trilineage differentiation of gold nanostar–labeled adipose-derived stem cells was induced with the appropriate media. Photothermolysis was performed on adipose-derived stem cells cultured alone or in co-culture with SKBR3 cancer cells. Results: Efficient uptake of gold nanostars occurred in adipose-derived stem cells, with persistence of the luminescent signal over 4 days. Labeling efficiency and signal quality were greater than with Qtracker. Gold nanostars did not affect cell phenotype, viability, or proliferation, and exhibited stronger luminescence than Qtracker throughout differentiation. Zones of complete ablation surrounding the gold nanostar–labeled adipose-derived stem cells were observed following photothermolysis in both monoculture and co-culture models. Conclusions: Gold nanostars effectively label adipose-derived stem cells without altering cell phenotype. Once labeled, photoactivation of gold nanostar–labeled adipose-derived stem cells ablates neighboring cancer cells, demonstrating the potential of adipose-derived stem cells as a vehicle for the delivery of site-specific cancer therapy.

Photothermal ablation of inflammatory breast cancer tumor emboli using plasmonic gold nanostars

Inflammatory breast cancer (IBC) is rare, but it is the most aggressive subtype of breast cancer. IBC has a unique presentation of diffuse tumor cell clusters called tumor emboli in the dermis of the chest wall that block lymph vessels causing a painful, erythematous, and edematous breast. Lack of effective therapeutic treatments has caused mortality rates of this cancer to reach 20%–30% in case of women with stage III–IV disease. Plasmonic nanoparticles, via photothermal ablation, are emerging as lead candidates in next-generation cancer treatment for site-specific cell death. Plasmonic gold nanostars (GNS) have an extremely large two-photon luminescence cross-section that allows real-time imaging through multiphoton microscopy, as well as superior photothermal conversion efficiency with highly concentrated heating due to its tip-enhanced plasmonic effect. To effectively study the use of GNS as a clinically plausible treatment of IBC, accurate three-dimensional (3D) preclinical models are needed. Here, we demonstrate a unique in vitro preclinical model that mimics the tumor emboli structures assumed by IBC in vivo using IBC cell lines SUM149 and SUM190. Furthermore, we demonstrate that GNS are endocytosed into multiple cancer cell lines irrespective of receptor status or drug resistance and that these nanoparticles penetrate the tumor embolic core in 3D culture, allowing effective photothermal ablation of the IBC tumor emboli. These results not only provide an avenue for optimizing the diagnostic and therapeutic application of GNS in the treatment of IBC but also support the continuous development of 3D in vitro models for investigating the efficacy of photothermal therapy as well as to further evaluate photothermal therapy in an IBC in vivo model.

Plasmonic SERS nanochips and nanoprobes for medical diagnostics and bio-energy applications

The development of rapid, easy-to-use, cost-effective, high accuracy, and high sensitive DNA detection methods for molecular diagnostics has been receiving increasing interest. Over the last five years, our laboratory has developed several chip-based DNA detection techniques including the molecular sentinel-on-chip (MSC), the multiplex MSC, and the inverse molecular sentinel-on-chip (iMS-on-Chip). In these techniques, plasmonic surface-enhanced Raman scattering (SERS) Nanowave chips were functionalized with DNA probes for single-step DNA detection. Sensing mechanisms were based on hybridization of target sequences and DNA probes, resulting in a distance change between SERS reporters and the Nanowave chip’s gold surface. This distance change resulted in change in SERS intensity, thus indicating the presence and capture of the target sequences. Our techniques were single-step DNA detection techniques. Target sequences were detected by simple delivery of sample solutions onto DNA probe-functionalized Nanowave chips and SERS signals were measured after 1h - 2h incubation. Target sequence labeling or washing to remove unreacted components was not required, making the techniques simple, easy-to-use, and cost effective. The usefulness of the techniques for medical diagnostics was illustrated by the detection of genetic biomarkers for respiratory viral infection and of dengue virus 4 DNA.

Abstract 67: Breast Cancer Cell Ablation Using Nanoparticle-Engineered Adipose-Derived Stem Cells

PURPOSE: Inflammatory breast cancer (IBC) is an aggressive disease characterized by the formation of tumor emboli, rapid local invasion, and lymphatic dissemination. Furthermore, IBC rapidly develops therapeutic resistance and evades immune surveillance and attack. For these reasons, the treatment of inflammatory breast cancer is extremely challenging and new therapeutic approaches are needed. Numerous studies have shown that adipose derived stem cells (ASCs), which are abundant in breast tissue, are recruited to the tumor microenvironment where they influence tumor progression. We have previously demonstrated the feasibility of using nanoparticles in conjunction with ASCs in treatmentresistant breast cancer. In this study, we show that ASCs localize to IBC tumor emboli and can be used as a targeted delivery vehicle for cancer nanotherapeutics.

Plasmonic nanochip for SERS chemical and biomedical sensing

The development of rapid, easy-to-use and highly sensitive DNA detection methods has received increasing interest for medical diagnostics and research purposes. Our laboratory has developed several chip-based DNA biosensors including molecular sentinel-on-chip (MSC), multiplex MSC, and inverse molecular sentinel-on-chip (iMS-on-Chip). These sensors use surface-enhanced Raman scattering (SERS) plasmonic chips, functionalized with DNA probes for single-step DNA detection. The sensing mechanisms is based on the hybridization of target sequences and DNA probes, resulting in a displacement of a SERS reporter from the chip surface. This distance increase results in change in SERS signal intensity from the reporter, thus indicating the capture, and therefore the presence, of the target nucleic acid sequence. The nucleic acid probes and the SERS chip, which compose the sensing platform, were designed for single-step DNA detection. The target sequences are detected by delivery of a sample solutions on a functionalized chip and characterization of the SERS signals, after 1 - 2 hr incubation. These techniques avoid labeling of the target sequence or washing to remove unreacted components, making them easy-to-use and cost effective. The use of SERS chip for medical diagnostics was demonstrated by detecting genetic biomarkers for respiratory viral infection and the DNA of dengue virus 4.

Nanosensors for nucleic acid targets detection using SERS

Single cell analysis can aid the study of molecular events responsible for cellular functions and unveil their connections to the biological functions of an organism. Biosensors based on surface enhanced Raman spectroscopy (SERS) can be used to this end and offer several advantages over other sensing platforms, such as sensitivity and multiplexed capabilities, among others. While SERS nanosensors/nanoparticles have been used for analysis in single cells, the delivery of such biosensors relies on cellular uptake, which requires long incubation time and has different efficiencies among cell lines. Nanosensors based on tapered optical fibers, instead, can be inserted in single cells and detect target molecules in subcellular compartment. The combination of these sensing devices with the transduction mechanism of nucleic acid based nanoprobes (i.e. inverse molecular sentinels) will permit the more direct detection of nucleic acids within single cells. This paper presents the development of tapered fiber-based biosensors for the detection of nucleic acid biomarkers in plant cells. The use of inverse molecular sentinels in plant cell was demonstrated. Sensors based on tapered fibers were fabricated and used to measure SERS from a single cell.

Plasmonic fano resonance sensing system using gold nanosphere and J-aggregates

Demonstrated herein is a simple method for the induction of J-aggregate formation in a colloidal solution of gold nanoparticles through the use of pseudoisocyanine (PIC) and polyvinyl sulfate. The plasmon-exciton coupling of the nanoparticle J-aggregate complex results in a split lineshape absorption spectrum with upper and lower plexcitonic branches. The use of nanoparticles with various plasmon resonances causes a shift in the upper plexcitonic band while the lower plexcitonic band remains at the same wavelength.