Quantum dot encapsulated nanocolloidal bioconjugates function as bioprobes for in vitro intracellular imaging

Stimuli-Mediated Specific Isolation of Exosomes from Blood Plasma for High-Throughput Profiling of Cancer Biomarkers

Exosomes, ranging from 30-150 nm in diameter, have emerged as promising non-invasive biomarkers for the diagnosis and prognosis of numerous diseases. However, current research on exosomes is largely restricted by the lack of an efficient method to isolate exosomes from real samples. Herein, the first stimuli-mediated enrichment and purification system to selectively and efficiently extract exosomes from clinical plasma for high-throughput profiling of exosomal mRNAs as cancer biomarkers is presented. This novel isolation system relies on specific installation of the stimuli-responsive copolymers onto exosomal phospholipid bilayers, by which the enrichment and purification are exclusively achieved for exosomes rather than the non-vesicle counterparts co-existing in real samples. The stimuli-mediated isolation system outperforms conventional methods such as ultracentrifugation and polyethylene glycol-based precipitation in terms of isolation yield, purity, and retained bioactivity. The high performance of the isolation system is demonstrated by enriching exosomes from 77 blood plasma samples and validated the clinical potentials in profiling exosomal mRNAs for cancer diagnosis and discrimination with high accuracy. This simple isolation system can boost the development of extracellular vesicle research, not limited to exosomes, in both basic and clinical settings.

Research Progress in the Synthesis of Targeting Organelle Carbon Dots and Their Applications in Cancer Diagnosis and Treatment

With increasing knowledge about diseases at the histological, cytological to sub-organelle level, targeting organelle therapy has gradually been envisioned as an approach to overcome the shortcomings of poor specificity and multiple toxic side effects on tissues and cell-level treatments using the currently available therapy. Organelle carbon dots (CDs) are a class of functionalized CDs that can target organelles. CDs can be prepared by a "synchronous in situ synthesis method" and "asynchronous modification method." The superior optical properties and good biocompatibility of CDs can be preserved, and they can be used as targeting particles to carry drugs into cells while reducing leakage during transport. Given the excellent organelle fluorescence imaging properties, targeting organelle CDs can be used to monitor the physiological metabolism of organelles and progression of human diseases, which will provide advanced understanding and accurate diagnosis and targeted treatment of cancers. This study reviews the methods used for preparation of targeting organelle CDs, mechanisms of accurate diagnosis and targeted treatment of cancer, as well as their application in the area of cancer diagnosis and treatment research. Finally, the current difficulties and prospects for targeting organelle CDs are prospected.

Pivotal Role of Quantum Dots in the Advancement of Healthcare Research

The quantum dot is a kind of nanoparticle whose dimension is smaller than the size of a typical nanoparticle ranging from tens of nanometers to a few hundredths of nanometers. The quantum mechanical behavior associated with the quantum dot displays different optical and electronic properties, enabling the quantum dot to find potential applications in a multitude of areas such as solar cells, light-emitting diodes, lasers, and biomedical applications. The objective of this investigation is to explore its fundamentals, synthesis, and applications, especially in the healthcare domain. We have discussed the quantum dot synthesis techniques using chemical methods, namely, wet-chemical methods and vapor-phase methods and plasma processing methods, namely, an ion sputtering method and plasma-enhanced chemical vapor deposition method. We have thoroughly investigated the application of quantum dots in imaging, diagnostics, and gene therapy areas. A significant outcome of this review is to propose quantum dots as a new modality in the treatment of cancer and gene therapeutics in the healthcare domain and the potentials of artificial intelligence to improve their performance via the applications of neural networks.

Biocompatible and fluorescent water based NIR emitting CdTe quantum dot probes for biomedical applications

Proficient fluorescent-characteristics, cytotoxicity-behavior and antimicrobial-activity of near-infrared-emitting (NIR) CdTe quantum dots (QDs) were studied sumptuously as these QDs are having an excellence in deep-tissue dissemination of light. These, NIR-emitting QDs were synthesized using aqueous method, utilizing 3-mercaptopropionic-acid (3-MPA) as a stabilizer; it controls leakage of Cd and Te ions from CdTe QDs. However, encapsulation by polymers also prevents the same by seizing toxic consequence of prepared QDs which was confirmed from cytotoxicity studies. Therefore, easy modification according to biological environment of these encapsulated CdTe QDs can serve in bio imaging and distribution. Antimicrobial study investigated the toxic effects of QDs against bacterial strains and support cytotoxicity studies and showing maximum 26 mm zone of inhibition against bacterial strain. These, NIR fluorescent QDs possess many attractive optical properties over the standard fluorescent probes (organic dyes) and can replace these dyes, as there is no specific dye which works in NIR range.

Ultrasound Molecular Imaging as a Potential Non-invasive Diagnosis to Detect the Margin of Hepatocarcinoma via CSF-1R Targeting

Though radiofrequency ablation (RFA) is considered to be an effective treatment for hepatocellular carcinoma (HCC), but more than 30% of patients may suffer insufficient RFA (IRFA), which can promote more aggressive of the residual tumor. One possible method to counter this is to accurately identify the margin of the HCC. Colony-stimulating factor 1 receptor (CSF-1R) has been found to be restrictively expressed by tumor associated macrophages (TAMs) and monocytes which more prefer to locate at the boundary of HCC. Using biotinylation method, we developed a CSF-1R-conjugated nanobubble CSF-1R (NB_CSF–1R) using a thin-film hydration method for margin detection of HCC. CSF-1R expression was higher in macrophages than in HCC cell lines. Furthermore, immunofluorescence showed that CSF-1R were largely located in the margin of xenograft tumor and IFRA models. In vitro, NB_CSF–1R was stable and provided a clear ultrasound image even after being stored for 6 months. In co-culture, NB_CSF–1R adhered to macrophages significantly better than HCC cells (p = 0.05). In in vivo contrast-enhanced ultrasound imaging, the washout half-time of the NB_CSF–1R was significantly greater than that of NB_CTRL and Sonovue^® (p = 0.05). The signal intensity of the tumor periphery was higher than the tumor center or non-tumor region after NB_CSF–1R injection. Taken together, NB_CSF–1R may potentially be used as a non-invasive diagnostic modality in the margin detection of HCC, thereby improving the efficiency of RFA. This platform may also serve as a complement method to detect residual HCC after RFA; and may also be used for targeted delivery of therapeutic drugs or genes.

High-quality quantum dots for multiplexed bioimaging: A critical review

Bioimaging done using two or more fluorophores possessing different emission wavelengths can be termed as a multicolor/multiplexed bioimaging technique. Traditionally, images are captured sequentially using multiple fluorophores having specific excitation and emission. For this purpose, multifunctional nanoprobes, such as organic fluorophores, metallic nanoparticles, semiconductor quantum dots, and carbon dots (CDs) are used. Among these fluorophores, quantum dots (QDs) have emerged as an ideal probe for multiplexed bioimaging due to their unique property of size tunable emission. However, the usage of quantum dots in bioimaging is limited due to their toxicity. Furthermore, the reproducibility of optical properties is cynical. These desirable properties, along with enhancement in quantum efficiency, photostability, fluorescence lifetime, etc. can be achieved by stringent control over synthesis parameters. This review summarizes the desirable properties and synthesis methods of such superior QDs followed by their application in multiplexed imaging.

Bovine serum albumin encapsulation of near infrared fluorescent nano-probe with low nonspecificity and cytotoxicity for imaging of HER2-positive breast cancer cells

Breast cancer with HER2 overexpressing type links to malignant tumor growth and poor clinical outcome. Successful development of sensitive and selective nano-probe for identification of HER2-positive breast cancer cells is of great importance for breast cancer early diagnosis, subtype classification, and treatment planning. Herein, we report a HER2 antibody conjugated near infrared (NIR) emitted MnCuInS/ZnS qumtun dots (QDs) encapsulated bovine serum albumin (BSA) nano-probe for accurately targeted imaging of HER2-positive breast cancer cells. This NIR nano-probe shows good biocompatibility, low nonspecificity and cytotoxicity, high colloidal stability, and allows HER2-positive breast cancer cell identification with good selectivity. The practicality of this targeted NIR fluorescent nano-probe was proved by successful identifying HER2-positive breast cancer cells from HER2-negative breast cancer cells, which indicates that it can be efficiently applied in selective screening of HER2 overexpressing cancer cells, and provide a platform for the strategy design on the distinction of different breast cancer subtypes.