Surface-engineered erythrocyte membrane-camouflage fluorescent bioprobe for precision ovarian cancer surgery.

PURPOSE: Fluorescence imaging-guided surgery has been used in oncology. However, for tiny tumors, the current imaging probes are still difficult to achieve high-contrast imaging, leading to incomplete resection. In this study, we achieved precise surgical resection of tiny metastatic cancers by constructing an engineering erythrocyte membrane-camouflaged bioprobe (AR-M@HMSN@P). METHODS: AR-M@HMSN@P combined the properties of aggregation-induced emission luminogens (AIEgens) named PF3-PPh3 (P), with functional erythrocyte membrane modified by a modular peptide (AR). Interestingly, AR was composed of an asymmetric tripodal pentapeptide scaffold (GGKGG) with three appended modulars: KPSSPPEE (A6) peptide, RRRR (R4) peptide and cholesterol. To verify the specificity of the probe in vitro, SKOV3 cells with overexpression of CD44 were used as the positive group, and HLF cells with low expression of CD44 were devoted as the control group. The AR-M@HMSN@P fluorescence imaging was utilized to provide surgical guidance for the removal of micro-metastatic lesions. RESULTS: In vivo, the clearance of AR-M@HMSN@P by the immune system was reduced due to the natural properties inherited from erythrocytes. Meanwhile, the A6 peptide on AR-M@HMSN@P was able to specifically target CD44 on ovarian cancer cells, and the electrostatic attraction between the R4 peptide and the cell membrane enhanced the firmness of this targeting. Benefiting from these multiple effects, AR-M@HMSN@P achieved ultra-precise tumor imaging with a signal-to-noise ratio (SNR) of 15.2, making it possible to surgical resection of tumors < 1 mm by imaging guidance. CONCLUSION: We have successfully designed an engineered fluorescent imaging bioprobe (AR-M@HMSN@P), which can target CD44-overexpressing ovarian cancers for precise imaging and guide the resection of minor tumors. Notably, this work holds significant promise for developing biomimetic probes for clinical imaging-guided precision cancer surgery by exploiting their externally specified functional modifications.

Dual-Activated H2O2-Responsive AIE Probes for Oocyte Quality Assessment.

Nonobstructive azoospermia (NOA) is an important cause of infertility, and intracytoplasmic sperm injection (ICSI) is the mainstay of treatment for these patients. In cases where a sufficient number of sperm (usually 1-2) is not available, the selection of oocytes for ICSI is a difficult problem that must be solved. Here, we constructed a dual-activated oxidative stress-responsive AIE probe, b-PyTPA. The strong donor-acceptor configuration of b-PyTPA leads to twisted intramolecular charge transfer (TICT) effect that quenches the fluorescence of the probe, however, H2O2 would specifically remove the boronatebenzyl unit and release a much weaker acceptor, which inhibits TICT and restores the fluorescence. In addition, the presence of a pyridine salt makes b-PyTPA more hydrophilic, whereas removal of the pyridine salt increases the hydrophobicity of PyTPA, which triggers aggregation and further enhances fluorescence. Thus, the higher the intracellular level of oxidative stress, the stronger the fluorescence. In vitro, this dual-activated fluorescent probe is capable of accurately detecting senescent cells (high oxidative stress). More importantly, b-PyTPA was able to characterize senescent oocytes, as assessed by the level of oxidative stress. It is also possible to identify high quality oocytes from those obtained for subsequent ICSI. In conclusion, this dual-activated oxidative stress-assessment probe enables the quality assessment of oocytes and has potential application in ICSI.

Macrophage Membrane-Camouflaged Aggregation-Induced Emission Nanoparticles Enhance Photodynamic-Immunotherapy to Delay Postoperative Tumor Recurrence.

Surgery is a traditional tumor treatment, and immunotherapy can reduce the postoperative recurrence of tumors. However, the intrinsic limits of low responsive rate and non-tumor specificity of immunotherapy agents are still insufficient to address therapeutic demands. Herein, the macrophages membrane camouflaged nanoparticles (NPs), named M@PFC, consisting of the aggregation-induced emission photosensitizer (PF3-PPh3 ) and immune adjuvant (CpG), are reported. As the protein on the membrane interacts with the vascular cell adhesion molecule 1 (VCAM-1) of cancer cells, M@PFC efficiently transports CpG to the tumor. Meanwhile, M@PFC can evade clearance by the immune system and prolong the circulation time in vivo; thus, enhancing their accumulation in tumors. PF3-PPh3 promotes high production of reactive oxygen species (ROS) and triggers immune cell death (ICD) in tumor cells under light exposure. Importantly, CpG enrichment in tumors can stimulate tumor cells to produce immune factors to assist in enhancing ICD effects. The synergistic effect combining the PDT properties of the aggregation-induced emission (AIE)-active photosensitizer and immunotherapy properties of CpG significantly delays tumor recurrence after surgery. In conclusion, this strategy achieves the synergistic activation of the immune system for anti-tumor activity, providing a novel paradigm for the development of therapeutic nanodrugs to delay postoperative tumor recurrence.

Cancer-Associated Fibroblast Mimetic AIE Probe for Precision Imaging-Guided Full-Cycle Management of Ovarian Cancer Surgery.

Fluorescence imaging can improve surgical accuracy in ovarian cancer, but a high signal-to-noise ratio is crucial for tiny metastatic cancers. Meanwhile, intraoperative fluorescent surgical navigation modalities alone are still insufficient to completely remove ovarian cancer lesions, and the recurrence rate remains high. Here, we constructed a cancer-associated fibroblasts (CAFs)-mimetic aggregation-induced emission (AIE) probe to enable full-cycle management of surgery that eliminates recurrence. AIE molecules (P3-PPh3) were packed in hollow mesoporous silica nanoparticles (HMSNs) to form HMSN-probe and then coated with a CAFs membrane to prepare CAF-probe. First, due to the negative potential of the CAF-probe, the circulation time in vivo is elevated, which facilitates passive tumor targeting. Second, the CAF-probe avoids its clearance by the immune system and improves the bioavailability. Finally, the fibronectin on the CAF-probe specifically binds to integrin α-5 (ITGA5), which is highly expressed in ovarian cancer cells, enabling fluorescence imaging with a contrast of up to 8.6. CAF-probe-based fluorescence imaging is used to evaluate the size and location of ovarian cancer before surgery (preoperative evaluation), to guide tumor removal during surgery (intraoperative navigation), and to monitor tumor recurrence after surgery (postoperative monitoring), ultimately significantly improving the efficiency of surgery and completely eliminating tumor recurrence. In conclusion, we constructed a CAFs mimetic AIE probe and established a full-cycle surgical management model based on its precise imaging properties, which significantly reduced the recurrence of ovarian cancer.

Peptide-Conjugated Probe Inducing Mitochondrial Dysfunction and Self-Reporting Cell Apoptosis by Aggregated Proteins.

Inducing and monitoring cell apoptosis in a real-time manner are crucial for evaluating the therapeutic effect of drugs and avoiding excessive treatment. Although promising advancements have been made to monitor cell apoptosis by assessing cell membrane integrity, the chronic compromise of cellular fitness caused by imbalance proteostasis is not visible and hard to be detected. As an indicator for cell apoptosis, imaging of aggregated proteins provides a new direction. Herein, we design a peptide-conjugated probe (QRKN) that can induce mitochondrial dysfunction for self-reporting cell apoptosis by imaging aggregated proteins. Specifically, QRKN can be cleaved into the α-helix-forming part (QRK) and azide-modified small-molecule part (N) by overexpressed cathepsin B (CB) in tumor cells. The QRK part can destroy the mitochondrial membrane and promote cytochrome c (Cyt c) efflux and caspase 3 expression. The other N part can inhibit the activity of mitochondrial complex IV (Mito-IV) and decrease the expression level of adenosine triphosphate (ATP). Two signaling pathways cooperatively induce mitochondrial dysfunction, resulting in protein aggregation and cell apoptosis ultimately. Meanwhile, the cell apoptosis process can be monitored based on QRKN, which is highly sensitive to the aggregated protein-triggered viscosity change. The self-reporting probe can monitor therapeutic responses and provide valuable diagnosis information.