Preparation of gelatin nanospheres incorporating quantum dots and iron oxide nanoparticles for multimodal cell imaging

Optically active organic and inorganic nanomaterials for biological imaging applications: A review

Recent advancements in the field of nanotechnology have enabled targeted delivery of drug agents in vivo with minimal side effects. The use of nanoparticles for bio-imaging has revolutionized the field of nanomedicine by enabling non-invasive targeting and selective delivery of active drug moieties in vivo. Various inorganic nanomaterials like mesoporous silica nanoparticles, gold nanoparticles, magnetite nanoparticles graphene-based nanomaterials etc., have been created for multimodal therapies with varied multi-imaging modalities. These nanomaterials enable us to overcome the disadvantages of conventional imaging contrast agents (organic dyes) such as lack of stability in vitro and in vivo, high reactivity, low-quantum yield and poor photo stability. Inorganic nanomaterials can be easily fabricated, functionalised and modified as per requirements. Recently, advancements in synthesis techniques, such as the ability to generate molecules and construct supramolecular structures for specific functionalities, have boosted the usage of engineered nanomaterials. Their intrinsic physicochemical properties are unique and they possess excellent biocompatibility. Inorganic nanomaterial research has developed as the most actively booming research fields in biotechnology and biomedicine. Inorganic nanomaterials like gold nanoparticles, magnetic nanoparticles, mesoporous silica nanoparticles, graphene-based nanomaterials and quantum dots have shown excellent use in bioimaging, targeted drug delivery and cancer therapies. Biocompatibility of nanomaterials is an important aspect for the evolution of nanomaterials in the bench to bedside transition. The conduction of thorough and meticulous study for safety and efficacy in well-designed clinical trials is absolutely necessary to determine the functional and structural relationship between the engineered nanomaterial and its toxicity. In this article an attempt is made to throw some light on the current scenario and developments made in the field of nanomaterials in bioimaging.

Imaging Constructs: The Rise of Iron Oxide Nanoparticles

Over the last decade, an important challenge in nanomedicine imaging has been the work to design multifunctional agents that can be detected by single and/or multimodal techniques. Among the broad spectrum of nanoscale materials being investigated for imaging use, iron oxide nanoparticles have gained significant attention due to their intrinsic magnetic properties, low toxicity, large magnetic moments, superparamagnetic behaviour and large surface area-the latter being a particular advantage in its conjunction with specific moieties, dye molecules, and imaging probes. Tracers-based nanoparticles are promising candidates, since they combine synergistic advantages for non-invasive, highly sensitive, high-resolution, and quantitative imaging on different modalities. This study represents an overview of current advancements in magnetic materials with clinical potential that will hopefully provide an effective system for diagnosis in the near future. Further exploration is still needed to reveal their potential as promising candidates from simple functionalization of metal oxide nanomaterials up to medical imaging.

CdSe quantum dots evaluation in primary cellular models or tissues derived from patients

In recent years quantum dots (QDs) have risen as useful luminescent nanoparticles with multiple applications ranging from laser, image displays and biomedical applications. Here we review and discuss the studies of these nanoparticles in patient derived cellular samples or tissues, including cellular models from iPSCs from patients, biopsied and post-mortem tissue. QD-based multiplexed imaging has been proved to overcome most of the major drawbacks of conventional techniques, exhibiting higher sensitivity, reliability, accuracy and simultaneous labeling of key biomarkers. In this sense, QDs are very promising tools to be further used in clinical applications including diagnosis and therapy approaches. Analyzing the possibilities of these materials in these biological samples gives an overview of the future applications of the nanoparticles in models closer to patients and their specific disease.

Visualization of Human Induced Pluripotent Stem Cells-Derived Three-Dimensional Cartilage Tissue by Gelatin Nanospheres

Recently, many studies on the three-dimensional (3D) fabrication of cells have been performed. Under these circumstances, it is indispensable to develop the imaging technologies and methodologies for noninvasive visualization of 3D cells fabricated. The objective of this study is to develop the labeling method of human induced pluripotent stem (iPS) cells-derived 3D cartilage tissue with gelatin nanospheres coincorporating three kinds of quantum dots (QD) and iron oxide nanoparticles (IONP) (GNS_QD+IONP). In this study, two labeling methods were performed. One is that a cartilage tissue was labeled directly by incubating with octaarginine (R8)-treated GNS_QD+IONP (direct labeling method). The other one is a "dissociation and labeling method." First, the cartilage tissue was dissociated to cells in a single dispersed state. Then, the cells were incubated with R8-GNS_QD+IONP in a monolayer culture. Finally, the cells labeled were fabricated to 3D pellets or cell sheets. By the direct labeling method, only cells residing in the surrounding site of cartilage tissue were labeled. On the contrary, the 3D cartilage pellets and the cell sheets were homogenously labeled and maintained fluorescently visualized over 4 weeks. In addition, the cartilage properties were histologically detected even after the process of dissociation and labeling. Homogenous labeling and visualization of human iPS cells-derived 3D cartilage tissue was achieved by the dissociation and labeling method with GNS_QD+IONP. Impact statement The homogenous labeling and visualization of human iPS cells-derived three-dimensional (3D) cartilage tissue was achieved over 4 weeks by the dissociation and labeling method with gelatin nanospheres coincorporating quantum dots (QD) and iron oxide nanoparticles (IONP) (GNS_QD+IONP). The cartilage properties of cells treated were maintained. It is concluded that the dissociation and labeling method with GNS_QD+IONP is a promising to visualize the human iPS cells-derived 3D cartilage tissue.

Preparation of cationized gelatin nanospheres incorporating molecular beacon to visualize cell apoptosis

The objective of this study is to prepare cationized gelatin nanospheres (cGNS) incorporating a molecular beacon (MB), and visualize cellular apoptosis. Two types of MB to detect the messenger RNA (mRNA) of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) (GAP MB), and caspase-3 (casp3 MB) were incorporated in cGNS, respectively. MB incorporated in cGNS showed the DNA sequence specificity in hybridization. The cGNS incorporation enabled MB to enhance the stability against nuclease to a significantly great extent compared with free MB. The cGNS incorporating GAP MB were internalized into the KUM6 of a mouse bone marrow-derived stem cell by an endocytotic pathway. The cGNS were not distributed at the lysosomes. After the incubation with cGNS, the cell apoptosis was induced at different concentrations of camptothecin. No change in the intracellular fluorescence was observed for cGNS_GAPMB. On the other hand, for the cGNS_casp3MB, the fluorescent intensity significantly enhanced by the apoptosis induction of cells. It is concluded that cGNS incorporating MB is a promising system for the visualization of cellular apoptosis.