Insulin-copper quantum clusters preparation and receptor targeted bioimaging

Photophysical Study of Heteroatom-Doped Carbon Dots-MnO2-Based Nanosensor: Selective Detection of Glutathione in the Nanomolar Level

Heteroatom doping on carbon dots (Cdots) has been developed as an efficient approach to modify its optical and electronic properties. The four different types of heteroatom-doped Cdots (undoped Cdots (u-Cdots, nitrogen-doped Cdots (N-Cdots), sulfur-doped Cdots (Cdots), nitrogen, sulfur codoped Cdots (N, S-Cdots)) have been synthesized through a simple heat treatment of 5 min. Among four different heteroatoms doped nanosensors, N, S-Cdots with MnO2 nanospheres (Mn NS) showed one of the best fluorescents "on-off-on" nanosensors for selective sensing of glutathione (GSH) and cell imaging. N, S-Cdots showed a high fluorescence quantum yield, good photostability, ionic strength, and pH stability. N, S-Cdots with Mn NS demonstrated extremely high fluorescence quenching efficiency and the maximum fluorescence recovery rate after adding GSH to the produced solution. The photophysical study of N, S-Cdots-Mn NS used as a sensor confirms the inner filter effect (IFE) quenching mechanism between them. The developed sensor has an 80 nM limit of detection (LOD) for GSH. The heteroatom-doped framework of Cdots plays a significant role in the sensitive detection of GSH. N, S-Cdots-Mn NS have good permeability, biocompatibility, and low toxicity, due to which it was used in the intracellular imaging of GSH in living cells. The prepared sensor is rapid, economical, less toxic, and highly applicable in diagnosing diseases.

Therapeutic potential of lactoferrin-coated iron oxide nanospheres for targeted hyperthermia in gastric cancer

Lactoferrin (LF) is a non-heme iron-binding glycoprotein involved in the transport of iron in blood plasma. In addition, it has many biological functions, including antibacterial, antiviral, antimicrobial, antiparasitic, and, importantly, antitumor properties. In this study, we have investigated the potential of employing lactoferrin-iron oxide nanoparticles (LF-IONPs) as a treatment modality for gastric cancer. The study confirms the formation of LF-IONPs with a spherical shape and an average size of 5 ± 2 nm, embedded within the protein matrix. FTIR and Raman analysis revealed that the Fe-O bond stabilized the protein particle interactions. Further, we conducted hyperthermia studies to ascertain whether the proposed composite can generate a sufficient rise in temperature at a low frequency. The results confirmed that we can achieve a temperature rise of about 7 °C at 242.4 kHz, which can be further harnessed for gastric cancer treatment. The particles were further tested for their anti-cancer activity on AGS cells, with and without hyperthermia. Results indicate that LF-IONPs (10 µg/ml) significantly enhance cytotoxicity, resulting in the demise of 67.75 ± 5.2% of cells post hyperthermia, while also exhibiting an inhibitory effect on cell migration compared to control cells, with the most inhibition observed after 36 h of treatment. These findings suggest the potential of LF-IONPs in targeted hyperthermia treatment of gastric cancer.

Protein-modified nanomaterials: emerging trends in skin wound healing

Prolonged inflammation can impede wound healing, which is regulated by several proteins and cytokines, including IL-4, IL-10, IL-13, and TGF-β. Concentration-dependent effects of these molecules at the target site have been investigated by researchers to develop them as wound-healing agents by regulating signaling strength. Nanotechnology has provided a promising approach to achieve tissue-targeted delivery and increased effective concentration by developing protein-functionalized nanoparticles with growth factors (EGF, IGF, FGF, PDGF, TGF-β, TNF-α, and VEGF), antidiabetic wound-healing agents (insulin), and extracellular proteins (keratin, heparin, and silk fibroin). These molecules play critical roles in promoting cell proliferation, migration, ECM production, angiogenesis, and inflammation regulation. Therefore, protein-functionalized nanoparticles have emerged as a potential strategy for improving wound healing in delayed or impaired healing cases. This review summarizes the preparation and applications of these nanoparticles for normal or diabetic wound healing and highlights their potential to enhance wound healing.

Insulin-cobalt core-shell nanoparticles for receptor-targeted bioimaging and diabetic wound healing

Diabetic wounds represent a major issue in medical care and need advanced therapeutic and tissue imaging systems for better management. The utilization of nano-formulations involving proteins like insulin and metal ions plays significant roles in controlling wound outcomes by decreasing inflammation or reducing microbial load. This work reports the easy one-pot synthesis of extremely stable, biocompatible, and highly fluorescent insulin-cobalt core-shell nanoparticles (ICoNPs) with enhanced quantum yield for their highly specific receptor-targeted bioimaging and normal and diabetic wound healing in vitro (HEKa cell line). The particles were characterized using physicochemical properties, biocompatibility, and wound healing applications. FTIR bands at 670.35 cm^-1, 849.79, and 973.73 indicating the Co-O bending, CoO-OH bond, and Co-OH bending, respectively, confirm the protein-metal interactions, which is further supported by the Raman spectra. In silico studies indicate the presence of cobalt binding sites on the insulin chain B at 8 GLY, 9 SER, and 10 HIS positions. The particles exhibit a magnificent loading efficiency of 89.48 ± 0.049% and excellent release properties (86.54 ± 2.15% within 24 h). Further, based on fluorescent properties, the recovery process can be monitored under an appropriate setup, and the binding of ICoNPs to insulin receptors was confirmed by bioimaging. This work helps synthesize effective therapeutics with numerous wound-healing promoting and monitoring applications.

In Silico and In Vitro Analysis of MAP3773c Protein from Mycobacterium avium subsp. Paratuberculosis

Simple Summary

Paratuberculosis is a disease that is caused by Mycobacterium avium subsp. paratuberculosis, a bacterium that survives inside a cell to cause disease. This bacterium therefore needs the nutrients of the cell to survive. Zinc and iron are very important elements in its nutrition and are necessary to carry out many of its survival functions, so the cell develops mechanisms to eliminate these pathogenic bacteria to continue living. One of these mechanisms is the elimination of iron as a strategy to kill the bacteria. In this research, we took on the task of studying one of the proteins of the bacterium called MAP3773c, along with its structure, some of its properties and its particular characteristics. In relation to the affinity for zinc and iron to bind to it, we are interested in discovering and making it known to the scientific community whether MAP3773c is related to the pathology of the disease.

Abstract

Paratuberculosis is a disease caused by Mycobacterium avium subsp. paratuberculosis (MAP). It is of great interest to better understand the proteins involved in the pathogenicity of this organism in order to be able to identify potential therapeutic targets and design new vaccines. The protein of interest–MAP3773c–was investigated, and molecular modeling in silico, docking, cloning, expression, purification, and partial characterization of the recombinant protein were achieved. In the in silico study, it was shown that MAP3773c of MAP has 34% sequence similarity with Mycobacterium tuberculosis (MTB) FurB, which is a zinc uptake regulator (Zur) protein. The docking data showed that MAP3773c exhibits two metal-binding sites. The presence of structural Zn²⁺ in the purified protein was confirmed by SDS-PAGE PAR staining. The purification showed one band that corresponded to a monomer, which was confirmed by liquid chromatography–mass spectrometry (LC-MS). The presence of a monomer was verified by analyzing the native protein structure through BN-SDS-PAGE (Native Blue (BN) Two-Dimensional Electrophoresis) and BN–Western blotting. The MAP3773c protein contains structural zinc. In conclusion, our results show that MAP3773c displays the features of a Fur-type protein with two metal-binding sites, one of them coordinating structural Zn²⁺.

Recent progress in polymeric non-invasive insulin delivery

The design of carriers for insulin delivery has recently attracted major research attentions in the biomedical field. In general, the release of drug from polymers is driven via a variety of polymers. Several mechanisms such as matrix release, leaching of drug, swelling, and diffusion are usually adopted for the release of drug through polymers. Insulin is one of the most predominant therapeutic drugs for the treatment of both diabetes mellitus; type-I (insulin-dependent) and type II (insulin-independent). Currently, insulin is administered subcutaneously, which makes the patient feel discomfort, pain, hyperinsulinemia, allergic responses, lipodystrophy surrounding the injection area, and occurrence of miscarried glycemic control. Therefore, significant research interest has been focused on designing and developing new insulin delivery technologies to control blood glucose levels and time, which can enhance the patient compliance simultaneously through alternative routes as non-invasive insulin delivery. The aim of this review is to emphasize various non-invasive insulin delivery mechanisms including oral, transdermal, rectal, vaginal, ocular, and nasal. In addition, this review highlights different smart stimuli-responsive insulin delivery systems including glucose, pH, enzymes, near-infrared, ultrasound, magnetic and electric fields, and the application of various polymers as insulin carriers. Finally, the advantages, limitations, and the effect of each non-invasive route on insulin delivery are discussed in detail.

Insulin Complexation with Cyclodextrins-A Molecular Modeling Approach

Around 5% of the population of the world is affected with the disease called diabetes mellitus. The main medication of the diabetes is the insulin; the active form is the insulin monomer, which is an instable molecule, because the long storage time, or the high temperature, can cause the monomer insulin to adapt an alternative fold, rich in β-sheets, which is pharmaceutically inactive. The aim of this study is to form different insulin complexes with all the cyclodextrin used for pharmaceutical excipients (native cyclodextrin, methyl, hydroxyethyl, hydroxypropyl and sulfobutylether substituted β-cyclodextrin), in silico condition, with the AutoDock molecular modeling program, to determine the best type of cyclodextrin or cyclodextrin derivate to form a complex with an insulin monomer, to predict the molar ratio, the conformation of the complex, and the intermolecular hydrogen bonds formed between the cyclodextrin and the insulin. From the results calculated by the AutoDock program it can be predicted that insulin can make a stable complex with 5–7 molecules of hydroxypropyl-β-cyclodextrin or sulfobutylether-β-cyclodextrin, and by forming a complex potentially can prevent or delay the amyloid fibrillation of the insulin and increase the stability of the molecule.

Protection of lead-induced cytotoxicity using paramagnetic nickel–insulin quantum clusters

Pb-toxicity is associated with inflammation which leads to delay in wound healing. Pb²⁺ utilizes calcium ion channels to enter the cell. Therefore, to achieve effective healing in a Pb-poisoned system, capturing Pb²⁺ from the circulatory system would be an effective approach without hampering the activity of the calcium ion channel. In this work insulin–nickel fluorescent quantum clusters (INiQCs) have been synthesized and used for the specific detection of Pb²⁺ ions in vitro and in cell-free systems. INiQCs (0.09 μM) can detect Pb²⁺ concentrations as low as 10 pM effectively in a cell-free system using the fluorescence turn-off method. In vitro INiQCs (0.45 μM) can detect Pb²⁺ concentrations as low as 1 μM. INiQCs also promote wound healing which can easily be monitored using the bright fluorescence of INiQCs. INiQCs also help to overcome the wound recovery inhibitory effect of Pb²⁺in vitro using lead nitrate. This work helps to generate effective biocompatible therapeutics for wound recovery in Pb²⁺ poisoned individuals.

Receptor targeted ferromagnetic Insulin–Nickel Quantum fluorescence Clusters (INiQCs) can specifically detect Pb²⁺ and prevents Pb²⁺ poisoning.

Functionality of receptor targeted zinc-insulin quantum clusters in skin tissue augmentation and bioimaging

Quantum clusters with target specificity are suitable for tissue-specific imaging. In the present work, amorphous zinc insulin quantum clusters (IZnQCs) had been synthesised to promote and monitor wound recovery. Easy synthesis, biocompatibility, stability, enhanced quantum yield, and solubility made the cluster suitable for preclinical/clinical exploration. Zn²⁺ is known for its binding to insulin hexamer. Here we report the reformation of the structure in a quantum cluster form in the presence of Zn²⁺. The formation of IZnQCs was confirmed by the change in zeta potential from -25.6 mV to -17.9 mV and also the formation of protein metal interaction was confirmed in FTIR bands at 450, 480, and 613 cm^-1 for Zn-O, Zn-N, and Zn-S, respectively. HRTEM-EDS and SAED data analysis showed an amorphous nature of the cluster. The binding of IZnQCs to the cells has been confirmed using confocal microscopy. IZnQCs showed a synergistic effect in wound recovery than insulin or Zn²⁺ alone. Further due to high fluorescence this recovery process can be monitored under an appropriate setup. Wound healing promotional activity, target specificity, and fluorescence properties make the IZnQCs ideal to use for bioimaging along with promoting and monitoring of wound recovery agent.