Glutamic Acid Modified Gold Nanorod Sensor for the Detection of Calcium ions in Neuronal Cells.

Calcium (Ca2+) ions play a crucial role in the functioning of neurons, governing various aspects of neuronal activity such as rapid modulation and alterations in gene expression. Ca2+ signaling has a significant impact on the development of diseases and the impairment of neuronal functions. Herein, the study reports a Ca2+ ion sensor in neuronal cells using a gold nanorod. The gold nanorod (GA-GNR) conjugated glutamic acid developed in the study was used as a nano-bio probe for the experimental and in vitro detection of calcium. The nanosensor is colloidally stable, preserves plasmonic properties, and shows good viability in neuronal cells, as well as promoting neuron cell line growth. The cytotoxicity and cell penetration of the nanosensor are studied using Raman spectroscopy, brightfield and darkfield microscopy imaging, and MTT assays. The quantification of Ca2+ ions in neuronal cells is determined by monitoring the surface plasmon resonance (SPR) of the GA-GNR. The change in the intensity profile in the presence of Ca2+ incubated neurons was effectively used to develop a portable prototype of an optical Ca2+ sensor, proposing it as a tool for neurodegenerative disease diagnosis and neuromodulation evaluation.

Porphyrin and doxorubicin mediated nanoarchitectonics of copper clusters: a bimodal theranostics for cancer diagnosis and treatment in vitro.

Nanoarchitectonics, an emerging strategy, presents a promising alternative for developing highly efficient next-generation functional materials. Multifunctional materials developed using nanoarchitectonics help to mimic biological molecules. Porphyrin-based molecules can be effectively utilized to design such assemblies. Metal nanocluster is one of the functional materials that can shed more insight into developing nanoarchitectonic materials. Herein, an inherently near-infrared (NIR) fluorescing copper nanocluster (CuC)-mediated structural assembly via protoporphyrin IX (PPIX) and doxorubicin (Dox) is demonstrated as the functional material. Dox-loaded porphyrin-mediated CuC assembly shows singlet oxygen generation and 66% drug release at 15 min. Furthermore, the efficacy of this material is tested for cancer diagnosis and bimodal therapeutic strategy due to the fluorescing ability of the cluster and loading of PPIX as well as the drug, respectively. The nanoarchitecture exhibits targeted imaging and 83% cell death in HeLa cells upon laser irradiation with 10 nmoles and 20 nmoles of PPIX and Dox, respectively.

Copper Nanocluster Enables Simultaneous Photodynamic and Chemo Therapy for Effective Cancer Diagnosis and Treatment in Vitro.

Metal-nanocluster-mediated cancer diagnosis and therapy has drawn considerable attention in recent years due to the unique optical and photophysical properties of metal clusters. This type of material is highly useful for the diagnosis, treatment, and further follow-up of disease. However, a single treatment modality is not sufficient for a complete cure. The use of a multi-therapeutic strategy is among the most promising methods for effective treatment, along with an early-stage diagnosis. To address the multiple therapeutic modalities in a single nanomaterial, a copper nanocluster was synthesized using glutathione, having inherent singlet oxygen generation and emission at 674 nm. A tumor-targeting agent (folic acid) and an anticancer drug (doxorubicin) was conjugated to the copper cluster for cancer diagnosis via targeted imaging and further double therapy (photodynamic and chemotherapy) in vitro. 10.5 µg (18.1 nmol) of drug conjugated copper cluster shows 56 % cell death for 30 second laser irradiation in HeLa cells. Effective cancer cell imaging and therapeutic efficacy are demonstrated in vitro.