Noble metal nanoclusters (M NCs), defined as an aggregation of a few to tens of atoms, are considered a borderline between atoms and metal nanoparticles (M NPs), which tends to exhibit molecule-like behaviours such as discrete electronic state and size-dependent fluorescence. In the past decades, gold and silver nanoclusters (Au NCs and Ag NCs) have been massively explored and utilized in the field of industrial catalysis, optoelectronic devices, biological imaging, environmental detection, clinical diagnoses, and treatment. The analogue of Au and Ag NCs and platinum nanoclusters (Pt NCs), especially their biological applications, is relatively and rarely discussed. This review firstly investigates the synthetic methodology of Pt NCs including template-assisted and template-free approaches and then introduces their unique optical, catalytic, and thermal properties. Particular importance here is the biological applications of Pt NCs such as the bioimaging of various cells as a preferred fluorophore in contrast to traditional fluorescent markers (e.g., organic dye, semiconductor quantum dots, and fluorescent proteins), the usage of Pt NCs-based antitumour drugs as a new class chemotherapeutics for malignant tumour therapy, and the utilization of antibacteria as an alternative of Ag-based antibacterial agent. On the whole, the development of Pt NCs has already gained delectable progress; however, the study of ultrafine Pt NCs is at the beginning stage and there are still plenty of challenges like synthesis of near-infrared (NIR) fluorescent Pt NCs, the explicit signal pathway of cell apoptosis, and attempt in diverse biological applications that need to be urgently tackled in future.

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Background:Recently, the incidence of hematological malignancy, such as various leukemias, multiple myeloma and lymphoma, has revealed an increasing tendency, exhibiting a major impact on human health. Most of the available anti-cancer drugs, however, possess high non-targeted accumulation, dosage-associated toxicity, fast elimination, and lack specificity towards tumors, which restrict their utilization in clinical therapy. This extends also to cancer diagnosis where there is a lack of predictive biomarkers. Object: Noble metal nanomaterials (NM NMs) have the potential to overcome these shortcomings due to several characteristics including ease of synthesis, ultra-small size, easy surface modification and specific physicochemical properties. At present, gold-, silver-and platinumbased nanomaterials have been employed in the tracing and treatment of hematopoietic tumors through direct individual endocytosis or in innovative drug delivery systems (DDS) by conjugation with other targeting biomolecules. Purpose: In this mini review, we focus on the use of localized surface plasmon resonance (LSPR)-/surface-enhanced Raman scattering (SERS)-and fluorescence-based diagnosis of NM NMs in the hematological malignancies. Furthermore, the treatment of hematological malignancies utilized the NM NMs or NM NMs-based therapy technology in the chemotherapy, targeted therapy, and photothermal therapy are depicted in depth. The construction of effective and promising NM NMs or NM NMs-dependent theranostic methodology has the potential to provide interdisciplinary knowledge in the development of clinical tracing, diagnosis and treatment of refractory hematological diseases.

Platinum (Pt)-based chemotherapy drugs such as cisplatin are the first line and core options for the treatment of ovarian cancer (OC), while cisplatin resistance has a worse prognosis and low 5 year survival rate for patients. Chemotherapeutic drugs synthesized from nanomaterials have shown great potential in biomedicine; however, research into their application for OC resistance is rarely discussed. This study is proposed to elucidate the anti-tumor effects of polyethylenimine (PEI)-caged platinum nanoclusters (Pt NCs) on cisplatin-resistant OC. The results of confocal microscopy showed that Pt NCs entered cisplatinresistant OC cells dose-dependently and aggregated both in the cytoplasm and inside the nucleus. Subsequently, according to the results of CCK8 assay, wound healing assay, clone formation assay, Transwell assay, Ki-67 immunofluorescence assay, and flow cytometry assay, the proliferation and migration of cisplatin-resistant OC cells were inhibited by Pt NCs, as well as their apoptosis was promoted. In addition, we validated the anti-tumor effect of Pt NCs on regulating autophagy via monodansylcadaverine (MDC) staining, transmission electron microscopy observation of the autophagic ultrastructure, LC3-II-GFP and P62-GFP adenovirus single-label immunofluorescence, and western blotting; meanwhile, the role of Pt NCs in adjusting autophagy through modulation of the PI3K-AKT-mTOR signaling was verified. Based on these results, it appears that cisplatin-resistant OC cells can undergo apoptosis when Pt NCs activate autophagy by inhibiting the PI3K/AKT/mTOR pathway, exhibiting a promising potential of Pt NCs in the development of a novel chemotherapeutic agent for patients suffering from cisplatin-resistant OC.

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