Glycoprotein-based bioimaging of HeLa cancer cells by folate receptor and folate decorated graphene quantum dots

Use of gold/iron metal-organic framework nanoparticles (AuNPs/FeMOF)-modified glassy carbon electrode as an electrochemical sensor for the quantification of risperidone in patient plasma samples

Risperidone (RIS) is one of the most prescribed atypical antipsychotics approved for the treatment of various neuropsychiatric diseases. For the correlation of serum concentration and pharmacological effects of RIS, therapeutic drug monitoring is considered a fundamental concept for clinical application. This paper is provided to develop an electrochemical probe for the determination of RIS in biological samples by modification of glassy carbon electrode (GCE) using gold nanoparticles (AuNPs) and iron metal-organic-frameworks (FeMOFs). This probe fabrication process was characterized with various techniques including Fourier transform infrared (FTIR), emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), atomic force microscopy (AFM), and dynamic light scattering (DLS) to confirm the proper synthesis of materials and the sensors designing. The developed probe square-wave voltammetry (SWV) signal was linear upon RIS concentration from 0.02 to 50 µg/mL with a low limit of quantification (LOQ) of 0.02 µg/mL. Based on the validated method, high accuracy and precision, good specificity, and suitable stability of fabricated probes were achieved. As the ultimate step, this method was successfully applied for the quantification of RIS in patients' plasma samples with regular RIS consumption. The fabricated electrochemical demonstrates favorable clinical applicability due to its simplicity, high sensitivity, low sample pretreatment time, and rapid analysis time, making it a promising probe as an alternative to current separation-based methods. Also, the developed probe is cost-effective, as it uses a low amount of materials, decreases sample processing time, and utilizes inexpensive materials, which could remarkably reduce the overall cost of RIS concentration detection in clinical samples. The obtained results showed the potential of the developed probe for fast and reliable detection of RIS in plasma samples.

Recycling Motorcycle Exhaust Soot into Fluorescent Graphene Oxide Quantum Dots for Sensing Ferrocyanide Ions and Bioimaging Cells: A Method for Waste Utilization

Graphene oxide quantum dots (GOQDs) with a high quantum yield (50%) were synthesized using soot collected from a motorcycle (petroleum vehicle) exhaust pipe and applied as sensors for ferrocyanide ([Fe(CN)6]4-) ions and as bioimaging agents in a cancer cell line. X-ray photoelectron spectroscopy (XPS) data for the GOQDs revealed a C/O ratio of 2.49, which was close to that of graphene oxide (GO). The synthesized GOQDs exhibited strong blue fluorescence. High sensitivity to detect [Fe(CN)6]4- was reported in GOQDs with a detection limit of 0.46 nmol mL-1, and a strong linear relationship was achieved in the concentration range of 100-1100 μg L-1. The results demonstrate the utility of GOQDs for detecting [Fe(CN)6]4- in a real scenario. The GOQDs exhibited almost negligible cytotoxicity in cells and were internalized within 4 h of incubation, emitting blue fluorescence in the cytoplasm. This suggests that the GOQDs are promising bioimaging agents for biomedical applications. In general, these waste-derived GOQDs appear to be good chemo- and biosensing probes for real-life applications.

Advanced photoluminescent nanomaterials for targeted bioimaging of cancer cells

The investigation of changes in the membrane of cancer cells holds great potential for biomedical applications. Malignant cells exhibit overexpression of receptors, which can be used for targeted drug delivery, therapy, and bioimaging. Targeted bioimaging is one the most accurate imaging methods with a non-invasive nature, allowing for localization of the malignant cell without disrupting cellular integrity. Also, bioimaging has the potential to enhance the quality of established imaging techniques like magnetic resonance imaging (MRI). The utilization of nanoparticles in targeted bioimaging enhances the imaging quality and efficiency. Biocompatible nanoparticles can easily penetrate cell membranes, while they can be readily functionalized on their surfaces toward cell receptors. This study reviews reports on the application of new advanced photoluminescent materials for targeted bioimaging using the cell membrane receptors. Also, the limitations and advantages of the application of nanoparticles have been reviewed along with the clinical consideration of their uses in bioimaging.

Novel microfluidic development of pH-responsive hybrid liposomes: In vitro and in vivo assessment for enhanced wound Healing

Wound healing is a complex biological process crucial for tissue repair, especially in chronic wounds where healing is impaired. Liposomes have emerged as promising vehicles for delivering therapeutics to facilitate wound repair. Liposomes have been explored as effective carriers for therapeutic agents. However, traditional methods of liposome preparation face significant challenges, particularly in achieving consistent stability and precise control over drug encapsulation and release. This study addresses these challenges by pioneering the development of Hybrid Liposomes (HLPs) using microfluidic technology, which provides more controlled characteristics through precisely managed formulation parameters. Notably, the formation of Polydopamine (PDA) polymer within HLPs facilitates pH-responsive drug release, making them well-suited for acidic wound environments. Furthermore, surface modification with Folic Acid (FA) enhances cellular interaction with the HLPs. In vitro and in vivo studies demonstrate the efficacy of HLPs loaded with Hyaluronic Acid (HA) or Phenytoin (PHT) in promoting wound healing. Microfluidics optimizes the stability of HLPs over 90 days, underscoring their potential as a potent, antibiotic-free drug delivery system. In conclusion, this research advances the understanding of microfluidic optimization for HLPs, offering cutting-edge drug delivery systems. The transformative potential of targeted HLPs through microfluidics holds promise for revolutionizing wound healing and inspires optimism for effective therapeutic interventions.

Chitosan/platinum nanocubes/Mn(TPDCA)2-modified glassy carbon electrodes for the electrochemical quantification of amlodipine in unprocessed plasma samples

A novel electrochemical probe is developed to detect amlodipine (AMD) in unprocessed plasma samples. The fabrication process involves the synthesis of platinum nanocubes (Pt NCs) and Mn(TPDCA)2 complexes, which are then immobilized them onto the glassy carbon electrode (GCE) surface. The developed electrochemical probe demonstrates exceptional detection performance, with a wide dynamic range, outstanding selectivity, and commendable reproducibility. The linear range and lower limit of detection of the developed method are 53 nM-3.5 µM and 53 nM, respectively. Electrochemical experiments have been conducted to study the kinetics of electrooxidation on the modified electrode, revealing that the process is diffusion-controlled. Furthermore, method validation studies are performed to assess the accuracy, precision, and selectivity of the sensor, demonstrating excellent performance in all these aspects. Consequently, it can be concluded that the sensor is highly suitable for practical applications in drug analysis.

A review on synthesis, properties, and biomedical applications of graphene quantum dots (GQDs)

A new type of 0-dimensional carbon-based materials called graphene quantum dots (GQDs) is gaining significant attention as a non-toxic and eco-friendly nanomaterial. GQDs are nanomaterials composed of sp2hybridized carbon domains and functional groups, with their lateral size less than 10 nm. The unique and exceptional physical, chemical, and optical properties arising from the combination of graphene structure and quantum confinement effect due to their nano-size make GQDs more intriguing than other nanomaterials. Particularly, the low toxicity and high solubility derived from the carbon core and abundant edge functional groups offer significant advantages for the application of GQDs in the biomedical field. In this review, we summarize various synthetic methods for preparing GQDs and important factors influencing the physical, chemical, optical, and biological properties of GQDs. Furthermore, the recent application of GQDs in the biomedical field, including biosensor, bioimaging, drug delivery, and therapeutics are discussed. Through this, we provide a brief insight on the tremendous potential of GQDs in biomedical applications and the challenges that need to be overcome in the future.

Integrating of analytical techniques with enzyme-mimicking nanomaterials for the fabrication of microfluidic systems for biomedical analysis

Bioanalysis faces challenges in achieving fast, reliable, and point-of-care (POC) determination methods for timely diagnosis and prognosis of diseases. POC devices often display lower sensitivity compared to laboratory-based methods, limiting their ability to quantify low concentrations of target analytes. To enhance sensitivity, the synthesis of new materials and improvement of the efficiency of the analytical strategies are necessary. Enzyme-mimicking materials have revolutionized the field of the fabrication of new high-throughput sensing devices. The integration of microfluidic chips with analytical techniques offers several benefits, such as easy miniaturization, need for low biological sample volume, etc., while also enhancing the sensitivity of the probe. The use enzyme-like nanomaterials in microfluidic systems can offer portable strategies for real-time and reliable detection of biological agents. Colorimetry and electrochemical methods are commonly utilized in the fabrication of nanozyme-based microfluidic systems. The review summarizes recent developments in enzyme-mimicking materials-integrated microfluidic analytical methods in biomedical analysis and discusses the current challenges, advantages, and potential future directions.

Folic acid-mediated enhancement of the diagnostic potential of luminescent europium-doped hydroxyapatite nanocrystals for cancer biomaging

Early and accurate cancer diagnosis is crucial for improving patient survival rates. Luminescent nanoparticles have emerged as a promising tool in fluorescence bioimaging for cancer diagnosis. To enhance diagnostic accuracy, ligands promoting endocytosis into cancer cells are commonly incorporated onto nanoparticle surfaces. Folic acid (FA) is one such ligand, known to specifically bind to folate receptors (FR) overexpressed in various cancer cells such as cervical and ovarian carcinoma. Therefore, surface modification of luminescent nanoparticles with FA can enhance both luminescence efficiency and diagnostic accuracy. In this study, luminescent europium-doped hydroxyapatite (EuHAp) nanocrystals were prepared via hydrothermal method and subsequently modified with (3-Aminopropyl)triethoxysilane (APTES) followed by FA to target FR-positive human cervical adenocarcinoma cell line (HeLa) cells. The sequential grafting of APTES and then FA formed a robust covalent linkage between the nanocrystals and FA. Rod-shaped FA-modified EuHAp nanocrystals, approximately 100 nm in size, exhibited emission peaks at 589, 615, and 650 nm upon excitation at 397 nm. Despite a reduction in photoluminescence intensity following FA modification, fluorescence microscopy revealed a remarkable 120-fold increase in intensity compared to unmodified EuHAp, attributed to the enhanced uptake of FA-modified EuHAp. Additionally, confocal microscope observations confirmed the specificity and the internalization of FA-modified EuHAp nanocrystals in HeLa cells. In conclusion, the modification of EuHAp nanocrystals with FA presents a promising strategy to enhance the diagnostic potential of cancer bioimaging probes.

Super-resolution imaging of folate receptor alpha on cell membranes using peptide-based probes

Folate receptor alpha (FRα) is a vital membrane protein which have great association with cancers and involved in various biological processes including folate transport and cell signaling. However, the distribution and organization pattern of FRα on cell membranes remains unclear. Previous studies relied on antibodies to recognize the proteins. However, multivalent crosslinking and large size of antibodies confuse the direct observation to some extent. Fortunately, the emergence of peptide, which are small-sized and monovalent, has supplied us an unprecedented choice. Here, we applied fluorophore-conjugated peptide probe to recognize the FRα and study the distribution pattern of FRα on cell membrane using dSTORM super-resolution imaging technique. FRα were found to organized as clusters on cell surface with different sizes. And they have a higher expression level and formed larger clusters on various cancer cells than normal cells, which hinted that its specific distribution could be utilized for cancer diagnosis. Furthermore, we revealed that the lipid raft and cortical actin as restrictive factors for the FRα clustering, suggesting a potential assembly mechanism insight into FRα clustering on cell membrane. Collectively, our work clarified the morphology distribution and clustered organization of FRα with peptide probes at the nanometer scale, which paves the way for further revealing the relationship between the spatial organization and functions of membranal proteins.

Simple fluorescence chemosensor for the detection of calcium ions in water samples and its application in bio-imaging of cancer cells

This article describes the design, synthesis and characterization of a sensor suitable for practical measurement of ionized calcium in water samples and cancer cells. Calcium is an important ion in living organs and works as a messenger in several cellular functions. A lack of Ca ions interrupts the immune system and can lead to several diseases. A novel magnetic-polydopamine nanoparticle (PDNP)/rhodamine B (RhB)/folic acid (FA) nanoparticle was developed for the determination of calcium ions in MCF 7 cell lysates and water samples. Furthermore, the produced nanoparticle was employed for bioimaging of folate receptor (FR)-overexpressed cancer cells. This nanoprobe displayed a bright photoluminescence emission at 576 nm under an excitation wavelength of 420 nm. In the presence of calcium ions, the fluorescence emission of the MNPs-PDNPs/RhB/FA probe was proportionally decreased from 20 ng mL-1 to 100 ng mL-1 and 0.5 μg mL-1 to 20 μg mL-1 with a lower limit of quantification (LLOQ) of about 20 ng mL-1. The developed sensor showed a low-interference manner in the presence of possible coexistence interfering ions. In addition, this nanomaterial showed excellent biocompatibility with favorable differentiation ability to attach to the FR-positive cancer cells. The MNPs-PDNPs/RhB/FA nanoparticle has been utilized for bioimaging of the MCF 7 cell with favorable differentiation ability.

Concanavalin A-conjugated gold nanoparticle/silica quantum dot (AuNPs/SiQDs-Con A)-based platform as a fluorescent nanoprobe for the bioimaging of glycan-positive cancer cells

The glycan receptor is a glycosylphosphatidylinositol glycoprotein that is overexpressed on the surface of various cancer cells and has been utilized for wide applications. In the present work, the surface of citrate-capped gold nanoparticles (cit-AuNPs) was modified with mercaptopropionic acid (MPA) molecules to provide carboxylic groups for secondary functionalization with amine anchored-silica quantum dots (Si-NH₂ QDs) to produce cit-AuNPs-MPA/Si-NH₂ QDs fluorescent nanoparticles. Concanavalin A (Con A) molecules were attached through thiol-AuNP bonds to produce the final cit-AuNPs/MPA/Si-NH₂ QDs/Con A smart nanoparticles. The synthesized novel cit-AuNPs/MPA/Si-NH₂ QDs/Con A nanoparticles were utilized for the bioimaging of glycan-overexpressed breast cancer cells. Fluorescence microscopy and flow cytometry results revealed that the cit-AuNPs/MPA/Si-NH₂ QDs/Con A NPs can be efficiently taken up by cancer cells, with differentiating ability between overexpressed cancer cells and low-expressed normal cells. The cellular viability of the cit-AuNPs/MPA/Si-NH₂ QDs/Con A NPs was tested by the MTT test, proving their biocompatible nature at the 200 μg mL^-1 level. In conclusion, the fabricated cit-AuNPs/MPA/Si-NH₂ QDs/Con A NPs could be utilized for the bioimaging of MCF-7 cancer cells even in the clinical setting after proper in vivo validation.

Applications of Advanced Materials for Non-Enzymatic Glucose Monitoring: From Invasive to the Wearable Device

Diabetes mellitus (DM) is a global health problem leading to many complications and disabilities in life adjusting activities and even dead. Monitoring glucose levels is a key factor in diagnosis and management of DM. Conventional glucose sensors consisted of immobilized enzymes, are so susceptible to environmental conditions. In this way, nonenzymatic biosensors have attracted extensive attentions in many clinical diagnostics applications. To date, the finger pricking test is a common enzyme-based glucometer that is an invasive and inconvenient and may lead to infections in the injection sites. So, working on the possibility of cutaneous or subcutaneous insertion of devices as a noninvasive or minimally-invasive systems for continuous glucose controlling approaches through human biofluids (blood, perspiration, tears, saliva, etc.) have stimulated growing interest. This review summarizes recent nonenzymatic and noninvasive biofluids glucose monitoring systems which are highly resilience and stretchable to continuously adapt to body movements during common physical activity. Sensors are based on their constituent materials including carbon-based, metal nanoparticles, polymer, and hydrogel systems are classified for electrochemical, and optical glucose detection. Finally, we address the drawbacks and challenges of enzyme-free sensors which are aroused sustaining research passion to be used in point-of-care medical diagnostics applications.