Intraoperative diagnosis of metastatic tumors is of significant importance to the treatment of ovarian cancer. NIR‐II fluorescence imaging holds great promise for facile detection of tumor in situ with high sensitivity and resolution. Herein, a kind of NIR‐II fluorescent polymer dots (NIR‐II Pdots) with high brightness is developed for real‐time detection of metastatic ovarian cancer via NIR‐II fluorescence imaging. The NIR‐II Pdots are constructed via the self‐assembly of NIR‐II emissive aggregation induced emission luminogens (NIR‐II AIEgens) and poly (styrene)‐graft‐poly(ethylene glycol) in water. Such NIR‐II Pdots show very high fluorophore contents of nearly 30% and high quantum yield of 5.4% at emission maximum near 1020 nm. Further modification of the NIR‐II Pdots with targeting peptides yields NIR‐II Pdots‐GnRH, which can afford enhanced affinity of NIR‐II Pdots to ovarian cancer. Upon intravenous injection of the NIR‐II Pdots, whole‐body organs and vessels, peritoneal and lymphatic metastases of ovarian cancer are clearly visualized by NIR‐II fluorescence imaging. Under the guidance of NIR‐II fluorescence imaging, the metastatic foci with the diameter down to ≈2 mm can be facilely eliminated. The results indicate preclinical potential value of the NIR‐II Pdots for metastatic ovarian cancer detection.

Background: Most cancers favor glycolytic-based glucose metabolism. Hexokinase-2 (HK2), the first glycolytic rate-limiting enzyme, shows limited expression in normal adult tissues but is overexpressed in many tumor tissues, including ovarian cancer. HK2 has been shown to be correlated with the progression and chemoresistance of ovarian cancer and could be a therapeutic target. However, the systemic toxicity of HK2 inhibitors has limited their clinical use. Since follicle-stimulating hormone (FSH) receptor (FSHR) is overexpressed in ovarian cancer but not in nonovarian healthy tissues, we designed FSHR-mediated nanocarriers for HK2 shRNA delivery to increase tumor specificity and decrease toxicity. Results: HK2 shRNA was encapsulated in a polyethylene glycol-polyethylenimine copolymer modified with the FSH β 33–53 or retro-inverso FSH β 33–53 peptide. The nanoparticle complex with FSH peptides modification effectively depleted HK2 expression and facilitated a shift towards oxidative glucose metabolism, with evidence of increased oxygen consumption rates, decreased extracellular acidification rates, and decreased extracellular lactate and glucose consumption in A2780 ovarian cancer cells and cisplatin-resistant A2780CP counterpart cells. Consequently, cell proliferation, invasion and migration were significantly inhibited, and tumor growth was suppressed even in cisplatin-resistant ovarian cancer. No obvious systemic toxicity was observed in mice. Moreover, the nanoparticle complex modified with retro-inverso FSH peptides exhibited the strongest antitumor effects and effectively improved cisplatin sensitivity by regulating cisplatin transport proteins and increasing apoptosis through the mitochondrial pathway. Conclusions: These results established HK2 as an effective therapeutic target even for cisplatin-resistant ovarian cancer and suggested a promising targeted therapeutic approach.

Background: Peritoneal dissemination is common in advanced ovarian cancer. The completeness of cytoreduction is an independent prognostic factor. The intraoperative fluorescence imaging via tumor-specific near-infrared fluorophore might improve staging and surgical completeness. A promising target for ovarian cancer is the gonadotropin-releasing hormone receptor (GnRHR). This study aimed to develop a GnRHR-targeted near-infrared imaging probe for the detection of peritoneal metastases of ovarian cancer. Methods: Indocyanine green (ICG) was conjugated with GnRH antagonist peptide to develop an ovarian cancer-selective fluorescence probe GnRHa-ICG. GnRHR expression was detected in ovarian cancer tissues. The binding capacity of GnRHa-ICG and ICG was detected in both cancer cell lines and mouse models of peritoneal metastatic ovarian cancer using fluorescence microscopy, flow cytometry, and near-infrared fluorescence imaging. Results: Tissue microarray analysis revealed the overexpression of GnRHR in ovarian cancer. GnRH-ICG exhibited the binding capacity in a panel of cancer cell lines with different expression levels of GnRHR. In ovarian cancer mouse models, GnRHa-ICG signals were detected in peritoneal tumor lesions rather than normal peritoneal and intestines tissues. ICG showed intensive fluorescence signals in intestines. The tumor-to-muscle ratio and tumor-to-intestine ratio of GnRHa-ICG was 7.41 ± 2.82 and 4.37 ± 1.66, higher than that of ICG (4.60 ± 0.50 and 0.57 ± 0.06) at 2 h post administration. The fluorescence signal of peritoneal metastases peaked in intensity at 2 h and maintained for up to 48 h. ICG also showed a weak signal in the tumor lesions due to the enhanced permeability and retention effect, but the intensity decreased quickly within 48 h. Conclusions: The developed GnRHR-targeted imaging agent GnRHa-ICG could specifically detected peritoneal tumor lesions from normal peritoneal and intestines tissues because of the modification of GnRHa to ICG. The plateau period of GnRHa-ICG accumulation may be feasible for clinical applications in fluorescence-guided surgery. Our GnRHR imaging concept may be effective in other hormone-related tumors with upregulated GnRHR expression.

Late detection, peritoneal dissemination, chemoresistance and weak response to targeted therapeutics lead to high mortality in ovarian cancer. More efficient and specific tumor imaging and therapeutic agents are needed to improve the resection rate of surgery and to eliminate residual disease. The expression patterns of follicle-stimulating hormone (FSH) receptor make it a suitable target for ovarian cancer. Here, we report a strategy to develop an organic near-infrared probe for FSH receptor-targeted tumor imaging and photothermal therapy. The FSH-Rh760 probe was conjugated from the Rh760 fluorophore with the FSH β subunit 33–53 peptide. FSH-Rh760 specifically distinguished peritoneal metastatic ovarian cancerous foci from surrounding normal tissues with a high tumor-to-background ratio. The fluorescence signals in tumors peaked at 2 h and were cleared at 120 h postinjection. FSH-Rh760 treatment rapidly increased the abdomen temperature of mice up to ∼43 °C upon exposure to a near-infrared laser and effectively suppressed peritoneal tumor growth with tumor specificity. No significant systemic toxicities were observed. This study demonstrates the targeting ability and biocompatibility of FSH receptor-targeted theranostics and highlights its potential for clinical application in imaging-guided precision tumor resection and photothermal therapy to eliminate cancer lesions intraoperatively and postoperatively.

Cervical cancer has the highest incidence rate among all gynecologic malignancies. Photodynamic therapy (PDT) is a minimal invasive treatment widely used in various tumors. Intracellular generation of reactive oxygen species (ROS) is the essential effect in PDT, which also plays a pivotal role in ferroptosis. We hypothesize that ferroptosis inducer could enhance 5-Aminolevulinic acid (5-ALA) based PDT in cervical cancer. In vitro efficacy of 5-ALA-based photodynamic therapy was assessed via viability and apoptosis of cervical cancer cell line SiHa. Ferroptosis related markers were detected in SiHa cells received 5-ALA-PDT treatment. Anti-tumor effects of ferroptosis inducer sorafenib on 5-ALA-based photodynamic therapy were evaluated in both cell line and mouse model. Efficacy of 5-ALA-based photodynamic therapy was validated in SiHa cervical cancer cells. Increased intracellular generation of ROS and lipid ROS, accompanied by decreased GPX4 expression was observed after 5-ALA-PDT treatment, indicating ferroptosis triggered by photodynamic therapy. Ferroptosis inducer sorafenib, a clinical approved cancer drug, promotes 5-ALA-based photodynamic therapy in SiHa cells. In vivo combined anti-tumor effect of sorafenib and 5-ALA-based photodynamic therapy was confirmed in cervical cancer xenografts. We identified that 5-ALA-PDT inhibited cell viability and induced ferroptosis in cervical cancer. Ferroptosis inducer sorafenib promotes 5-ALA-based photodynamic therapy. These findings may provide new insights into mechanisms of photodynamic therapy and cervical cancer treatment in the future.

Lymph node metastases are common in advanced ovarian cancer and are associated with poor prognosis. Accurate intraoperative identification of lymph node metastases remains a challenge in ovarian cancer surgery due to the lack of tumor-specific intraoperative imaging tools. Here, we developed a gonadotropin-releasing hormone receptor (GnRHR)-targeted near-infrared (NIR) fluorescent probe, GnRHa-PEG-Rh760, through conjugation of a GnRH analog peptide with the Rh760 fluorophore and polyethylene glycol (PEG). A non-targeted probe (PEG-Rh760) served as control. In mouse models of subcutaneous xenografts, peritoneal and lymph node metastases derived from ovarian cancer cells, GnRHa-PEG-Rh760 showed superior tumor-specific accumulation. NIR fluorescence imaging revealed strong fluorescence signals localized to primary tumors, peritoneal lesions, and metastatic lymph nodes with no off-target signals in normal lymph nodes. The spatial co-localization between the NIR fluorescence of GnRHa-PEG-Rh760 and tumor-derived bioluminescence clearly confirmed the probe’s target specificity. GnRHa-PEG-Rh760 mainly accumulated in the tumor and liver and was gradually cleared at 96 h post-injection. The retention of fluorescence signals in normal ovary tissue further validated GnRHR-mediated binding of the probe. Notably, GnRHa-PEG-Rh760 exhibited excellent biocompatibility with no observed systemic toxicity as evidenced by hematologic and histopathologic analyses. These data demonstrate the potential of GnRHa-PEG-Rh760 as an intraoperative imaging agent, providing real-time fluorescence imaging guidance to optimize surgical precision. This study highlights the value of receptor-targeted molecular imaging probes in precision cancer surgery.