Activatable Hyaluronic Acid Nanoparticle as a Theranostic Agent for Optical/Photoacoustic Image-Guided Photothermal Therapy

Photothermal therapy (PTT) is an emerging treatment modality that is under intensive preclinical investigations for the treatment of various medical conditions, including cancer. However, the lack of targeting function of PTT agents hampers its clinical application. An effective and nontoxic delivery vehicle that can carry PTT agents into tumor areas is still needed urgently. In this study, we developed a multifunctional nanocomposite by loading copper sulfide (CuS) into Cy5.5-conjugated hyaluronic acid nanoparticles (HANP), obtaining an activatable Cy5.5–HANP/CuS (HANPC) nanocomposite. In this system, Cy5.5 fluorescent signal is quenched by CuS inside the particle until the whole nanocomposite is degraded by hyaluronidase present in tumor, giving strong fluorescence signals delineating the tumor. Importantly, CuS with strong NIR absorbance appears to be an excellent contrast agent for photoacoustic (PA) imaging and an effective PTT agent. After intravenous administration of HANPC into SCC7 tumor-bearing mice, high fluorescence and PA signals were observed in the tumor area over time, which peaked at the 6 h time point (tumor-to-normal tissue ratio of 3.25 ± 0.25 for optical imaging and 3.8 ± 0.42 for PA imaging). The tumors were then irradiated with a laser, and a good tumor inhibition rate (89.74% on day 5) was observed. Our studies further encourage application of this HA-based multifunctional nanocomposite for image-guided PTT in biomedical applications, especially in cancer theranostics

SPECT/CT images of MDA-MB-231 and A549 tumors by targeting MT1-MMP.

<p>(A) Static planar images of MDA-MB-231 tumor-bearing mice model and A549 tumor-bearing mice model after administration of 11.1 MBq/kg of [^99mTc](HYNIC-AF7P)(tricine)(TPPTS) at 0.5 and 2 h post injection. Excess amount (200 μg) of free AF7P was injected for blocking test. (B) Quantification of [^99mTc](HYNIC-AF7P)(tricine)(TPPTS) and [^99mTc](HYNIC-AF7P)(tricine)(TPPTS) (Blocking) in MDA-MB-231 tumor-bearing mice. Quantification of [^99mTc](HYNIC-AF7P)(tricine)(TPPTS) in A549 tumor-bearing mice. ROIs are shown as mean %ID/g ± SD.</p

Characterizations.

<p>(A) Chemical structure of [^99mTc]-(HYNIC-AF7p)(tricine)(TPPTS). (B) Radio-HPLC purity of [^99mTc]-(HYNIC-AF7p)(tricine)(TPPTS).</p

Development of a Radiolabeled Peptide-Based Probe Targeting MT1-MMP for Breast Cancer Detection

<div><p>Breast cancer is one of the most frequent and aggressive primary tumors among women of all races. Matrix metalloproteinase (MMPs), a family of zinc- and calcium-dependent secreted or membrane anchored endopeptidases, is overexpressed in varieties of diseases including breast cancer. Therefore, noninvasive visualization and quantification of MMP <i>in vivo</i> are of great interest in basic research and clinical application for breast cancer early diagnosis. Herein, we developed a ^99mTc labeled membrane type I matrix metalloproteinase (MT1-MMP) specific binding peptide, [^99mTc]-(HYNIC-AF7p)(tricine)(TPPTS), for <i>in vivo</i> detection of MDA-MB-231 breast tumor by single photon emission computed tomography (SPECT). [^99mTc]-(HYNIC-AF7p)(tricine)(TPPTS) demonstrated nice biostability and high MT1-MMP binding affinity <i>in vitro</i> and <i>in vivo</i>. Tumor-to-muscle ratio was found to reach to the highest (4.17±0.49) at 2 hour after intravenously administration of [^99mTc]-(HYNIC-AF7P)(tricine)(TPPTS) into MDA-MB-231 tumor bearing mice. Overall, [^99mTc]-(HYNIC-AF7P)(tricine)(TPPTS) demonstrated great potential for MT1-MMP targeted detection <i>in vivo</i> and it would be a promising molecular imaging probe that are probably beneficial to breast cancer early diagnoses.</p></div

Fluorescent immunohistochemistry for MT1-MMP expression in MDA-MB-435 and A549 tumors.

<p>More MT1-MMP expressed in MDA-MB-435 tumor was observed than that of in A549 tumor. Green: FITC conjugated donkey anti-Rabbit secondary antibody. Blue: DAPI. All signals were adjusted to the same scale. Scale bar equals10 μm.</p

Solution stability data for [^99mTc(HYNIC-AF7P)(tricine)(TPPTS)] in saline (A) and in the presence of excess cysteine (B) (1 mg/mL, pH = 7.4).

<p>Solution stability data for [^99mTc(HYNIC-AF7P)(tricine)(TPPTS)] in saline (A) and in the presence of excess cysteine (B) (1 mg/mL, pH = 7.4).</p

Cytotoxicity of AF7p analogs on MDA-MB-231 cells.

<p>No cytotoxicity was observed at different concentrations of AF7p, Cy5.5-AF7p and (HYNIC-AF7P)(tricine)(TPPTS).</p

Biodistribution of [^99mTc]-(HYNIC-AF7p)(tricine)(TPPTS) in mice bearing MDA-MB-231 tumor.

<p>Biodistribution of [^99mTc]-(HYNIC-AF7p)(tricine)(TPPTS) in mice bearing MDA-MB-231 tumor.</p

Cell labeling.

<p>(A) Chemical structure of Cy5.5 AF7p. (B) Colocalization of Cy5.5-AF7p and MT1-MMP on MDA-MB-231 and A549 cells. Red color is from Cy5.5 for Cy5.5-AF7p distribution on cellular membrane. Green color is from FITC conjugated donkey anti-rabbit secondary antibody for MT1-MMP localization. Blue color is from DAPI for nuclei visualization. Yellow color is merged color from Red and Green, indicating the colocalization of Cy5.5-AF7p and MT1-MMP. Scale bar equals 10 μm. (C). Blocking test for the specificity of Cy5.5-AF7p to MT1-MMP. Little of Cy5.5-AF7p was able to label MT1-MMP after excess amount of AF7p blocking.</p

Tumor to organ ratios of [^99mTc]-(HYNIC-AF7p)(tricine)(TPPTS) in B mice bearing MDA-MB-231 tumor.

<p>Tumor to organ ratios of [^99mTc]-(HYNIC-AF7p)(tricine)(TPPTS) in B mice bearing MDA-MB-231 tumor.</p