Activation of tumor suppressor p53 gene expression by magnetic thymine-imprinted chitosan nanoparticles

In vitro activation of anti-cancer gene expression by delivery of CRISPR/dCas9 ribonucleoproteins to suppress glioblastoma

Cancer has been a leading cause of death for decades. While many anti-cancer drugs exist, precisely targeting malignant cells is crucial for successful tumor treatment. This targeting can be achieved by activating anti-cancer genes, which specifically destroy malignant cells. CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) therapeutics provide a promising approach for gene activation. The technology involves utilizing the denatured Cas9 (CRISPR-associated) protein conjugated with a protein activator to deliver a ribonucleoprotein (RNP) complex including guide RNA into cells for the overexpression of specific proteins. In this study, several guide RNAs targeting cancer suppressor genes were employed. These genes included tumor protein p53 (TP53), human alpha-lactalbumin made lethal to tumor cells (HAMLET), melanoma differentiation-associated gene-7 (MDA7, IL24), phorbol-12-myristate-13-acetate-induced protein 1 (PMAIP1, NOXA), pro-apoptotic WT1 regulator (PAWR, PAR4), and TNF superfamily member 10 (TNFSF10, TRAIL). The dCas9/guide RNA complexes were then adsorbed onto magnetic epitope-imprinted nanoparticles. Uppsala 87 malignant glioma (U87MG) cells and induced astrocytes (noncancerous cells) were then treated with the RNP / nanoparticles. The overexpression of MDA7 and NOXA was monitored for at least 30 days using enzyme-linked immunosorbent assay (ELISA) kits. Finally, the induced astrocytes, first activated with these anti-cancer genes, were co-cultured with U87MG cells. This resulted in a "bystander" effect: the malignant U87MG cells underwent apoptosis, while the astrocytes survived.

Therapeutic applications of carbohydrate-based compounds: a sweet solution for medical advancement

Carbohydrates, one of the most abundant biomolecules found in nature, have been seen traditionally as a dietary component of foods. Recent findings, however, have unveiled their medicinal potential in the form of carbohydrates-derived drugs. Their remarkable structural diversity, high optical purity, bioavailability, low toxicity and the presence of multiple functional groups have positioned them as a valuable scaffold and an exciting frontier in contemporary therapeutics. At present, more than 170 carbohydrates-based therapeutics have been granted approval by varying regulatory agencies such as United States Food and Drug Administration (FDA), Japan Pharmaceuticals and Medical Devices Agency (PMDA), Chinese National Medical Products Administration (NMPA), and the European Medicines Agency (EMA). This article explores an overview of the fascinating potential and impact of carbohydrate-derived compounds as pharmacological agents and drug delivery vehicles.

The Use of Sensors in Blood-Brain Barrier-on-a-Chip Devices: Current Practice and Future Directions

The application of lab-on-a-chip technologies in in vitro cell culturing swiftly resulted in improved models of human organs compared to static culture insert-based ones. These chip devices provide controlled cell culture environments to mimic physiological functions and properties. Models of the blood-brain barrier (BBB) especially profited from this advanced technological approach. The BBB represents the tightest endothelial barrier within the vasculature with high electric resistance and low passive permeability, providing a controlled interface between the circulation and the brain. The multi-cell type dynamic BBB-on-chip models are in demand in several fields as alternatives to expensive animal studies or static culture inserts methods. Their combination with integrated biosensors provides real-time and noninvasive monitoring of the integrity of the BBB and of the presence and concentration of agents contributing to the physiological and metabolic functions and pathologies. In this review, we describe built-in sensors to characterize BBB models via quasi-direct current and electrical impedance measurements, as well as the different types of biosensors for the detection of metabolites, drugs, or toxic agents. We also give an outlook on the future of the field, with potential combinations of existing methods and possible improvements of current techniques.

Peptide Selection of MMP-1 for Electrochemical Sensing with Epitope-Imprinted Poly(TPARA-co-EDOT)s

Instead of molecularly imprinting a whole protein molecule, imprinting protein epitopes is gaining popularity due to cost and solubility issues. Belonging to the matrix metalloproteinase protein family, MMP-1 is an interstitial collagenase that degrades collagen and may be involved in cell migration, cell proliferation, the pro-inflammatory effect, and cancer progression. Hence, it can serve as a disease protein biomarker and thus be useful in early diagnosis. Herein, epitopes of MMP-1 were identified by screening its crystal structure. To identify possible epitopes for imprinting, MMP-1 was cleaved in silico with trypsin, pepsin at pH = 1.3, and pepsin at pH > 2.0 using Peptide Cutter, generating peptide fragments containing 8 to 12 amino acids. Five criteria were applied to select the peptides most suitable as potential epitopes for MMP-1. The triphenylamine rhodanine-3-acetic acid (TPARA) functional monomer was synthesized to form a stable pre-polymerization complex with a selected template epitope. The complexed functional monomer was then copolymerized with 3,4-ethoxylenedioxythiophene (EDOT) using potentiodynamic electropolymerization onto indium−tin−oxide (ITO) electrodes. The composition of the molecularly imprinted poly(TPARA-co-EDOT) (MIP) was optimized by maximizing the film’s electrical conductivity. Cyclic voltammetry was used to determine MMP-1 concentration in the presence of the Fe(CN)63−/Fe(CN)64− redox probe actuating the “gate effect.” A calibration curve was constructed and used to determine the usable concentration range and the limit of detection as ca. 0.001 to 10.0 pg/mL and 0.2 fg/mL MMP-1, respectively. Finally, the MMP-1 concentration in the A549 human lung (carcinoma) culture medium was measured, and this determination accuracy was confirmed using an ELISA assay.

Cellular Therapy Using Epitope-Imprinted Composite Nanoparticles to Remove α-Synuclein from an In Vitro Model

Several degenerative disorders of the central nervous system, including Parkinson’s disease (PD), are related to the pathological aggregation of proteins. Antibodies against toxic disease proteins, such as α-synuclein (SNCA), are therefore being developed as possible therapeutics. In this work, one peptide (YVGSKTKEGVVHGVA) from SNCA was used as the epitope to construct magnetic molecularly imprinted composite nanoparticles (MMIPs). These composite nanoparticles were characterized by dynamic light scattering (DLS), high-performance liquid chromatography (HPLC), isothermal titration calorimetry (ITC), Brunauer–Emmett–Teller (BET) analysis, and superconducting quantum interference device (SQUID) analysis. Finally, the viability of brain endothelial cells that were treated with MMIPs was measured, and the extraction of SNCA from CRISPR/dCas9a-activated HEK293T cells from the in vitro model system was demonstrated for the therapeutic application of MMIPs.

Chitosan from Crabs (Scylla serrata) Represses Hyperlipidemia-Induced Hepato-Renal Dysfunctions in Rats: Modulation of CD43 and p53 Expression

Hepato-renal dysfunctions associated with hyperlipidemia necessitates a continuous search for natural remedies. This study thus evaluated the effect of dietary chitosan on diet-induced hyperlipidemia in rats. A total of 30 male Wistar rats (90 ± 10) g were randomly allotted into six (6) groups (n = 5): Normal diet, High-fat diet (HFD), and Normal diet + 5% chitosan. The three other groups received HFD, supplemented with 1%, 3%, and 5% of chitosan. The feeding lasted for 6 weeks, after which the rats were sacrificed. The liver and kidneys were harvested for analyses. Hepatic alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) activity, and renal biomarkers (ALT, AST, urea, and creatinine) were assayed spectrophotometrically. Additionally, expression of hepatic and renal CD43 and p53 was estimated immunohistochemically. The HFD group had elevated bodyweight compared to normal which was reversed in the chitosan-supplemented groups. Hyperlipidemia caused a significant (p < 0.05) decrease in the hepatic (AST, ALT, and ALP) and renal (AST and ALT) activities, while renal urea and creatinine increased. Furthermore, the HFD group showed an elevated level of hepatic and renal CD43 while p53 expression decreased. However, groups supplemented with chitosan showed improved hepatic and renal biomarkers, as well as corrected the aberrations in the expressions of p53 and CD43. Conclusively, dietary chitosan inclusion in the diet (between 3% and 5%) could effectively improve kidney and liver functionality via abatement of inflammatory responses.

Epitope recognition of magnetic peptide-imprinted chitosan composite nanoparticles for the extraction of CRISPR/dCas9a proteins from transfected cells

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas9) technology is a powerful method for genetic modification (and regulation) that is of great current interest. The development of new, economical methods of detecting and extracting Cas9 (and/or dCas9) from transfected cells is thus an important advance. In this work, we employed molecular imprinting, using two peptides from the Cas9 protein, to make magnetic peptide-imprinted chitosan nanoparticles. dCas9 was encoded in a plasmid which was then transfected into human embryonic kidney (HEK293T) cells. The expression of dCas9 protein was measured by using total protein kits. Finally, the imprinted nanoparticles were used to extract dCas9 from transfected cell homogenates.

Cellular reprogramming with multigene activation by the delivery of CRISPR/dCas9 ribonucleoproteins via magnetic peptide-imprinted chitosan nanoparticles

Induced pluripotent stem cells are usually derived by reprogramming transcription factors (OSKM), such as octamer-binding transcription factor 4 (OCT4), (sex determining region Y)-box 2 (SOX2), Krüppel-like factor 4 (KLF4), and cellular proto-oncogene (c-Myc). However, the genomic integration of transcription factors risks the insertion of mutations into the genome of the target cells. Recently, the clustered regularly interspaced short palindromic repeat-associated protein 9 (CRISPR/Cas9) system has been used to edit genomes. In this work, dCas9-VPR (dCas9 with a gene activator, VP64-p65-Rta (VPR), fused to its c-terminus) and guide RNA (gRNA) combined to form ribonucleoproteins, which were immobilized on magnetic peptide-imprinted chitosan nanoparticles. These were then used to activate OSKM genes in human embryonic kidney (HEK) 293T cells. Four pairs of gRNAs were used for the binding site recognition to activate the OSKM genes. Transfected HEK293T cells were then prescreened for the high expression of OSKM proteins by immunohistochemistry images. The optimal gRNAs for OSKM expression were identified using quantitative real-time polymerase chain reaction and the staining of OSKM proteins. Finally, we found that the activated expression of one of the OSKM genes is up to three-fold higher than that of the other genes, enabling precise control of the cell differentiation.

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Molecularly imprinted polymer nanoparticles were used to deliver dCas9 ribonucleoproteins to activate OSKM genes.

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Two-guide RNAs for each OSKM gene were studied.

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Transfected HEK293T cells were then screened using immunohistochemistry.

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The optimal-guide RNAs for OSKM expression were also identified using qRT-PCR.

Immunotherapy of Hepatocellular Carcinoma with Magnetic PD-1 Peptide-Imprinted Polymer Nanocomposite and Natural Killer Cells

Programmed cell death protein 1 (PD-1) is a biomarker on the surface of cells with a role in promoting self-tolerance by suppressing the inflammatory activity of T cells. In this work, one peptide of PD-1 was used as the template for molecular imprinting to form magnetic peptide-imprinted poly(ethylene-co-vinyl alcohol) composite nanoparticles (MPIP NPs). The nanoparticles were characterized by dynamic light scattering (DLS), high-performance liquid chromatography (HPLC), Brunauer–Emmett–Teller (BET) analysis, and superconducting quantum interference device (SQUID) analysis. Natural killer 92 (NK-92) cells were added to these composite nanoparticles and then incubated with human hepatoma (HepG2) cells. The viability and the apoptosis pathway of HepG2 were then studied using cell counting kit-8 (CCK8) and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. These nanoparticles were found to significantly enhance the activity of natural killer cells toward HepG2 cells by increasing the expression of nuclear factor kappa B (NF-κB), caspase 8, and especially caspase 3.

Gold-decorated magnetic nanoparticles modified with hairpin-shaped DNA for fluorometric discrimination of single-base mismatch DNA

The authors describe the use of gold-decorated magnetic nanoparticles (Au/MNPs) in discriminating DNA sequences with a single-base (guanine) mismatch. The Au/MNPs were characterized through dynamic light scattering, X-ray diffraction, superconducting quantum interference device, and UV/visible spectroscopy. They were then conjugated to a probe oligomer consisting of a hairpin-shaped DNA sequence carrying two signalling fluorophores: fluorescein at its 3' end and pyrene in the loop region. When interacting with the target DNA sequences, the hybridized probe-target duplex renders the pyrene signal (at excitation/emission wavelengths of 345/375 nm) either quenched or unquenched. Quenching (or nonquenching) of the pyrene fluorescence depends on the presence of a guanine (or a nonguanine) nucleotide at the designated polymorphic site. The linear range of hybridization in these Au/MNPs is from 0.1 nM to 1.0 μM of ssDNA. Conceivably, this system may serve as a single-nucleotide polymorphism probe. Graphical Abstract Schematic presentation of probe-conjugated Au/MNP preparation (upper panel) and working principle to discriminate DNA with or without single-base (guanine) mismatch sequences at the polymorphic sites (lower panel). Py denotes pyrene-hooked pyrrolocytidine; F denotes fluorescein.

Chitosan-Based Nanomaterials for Drug Delivery

This review discusses different forms of nanomaterials generated from chitosan and its derivatives for controlled drug delivery. Nanomaterials are drug carriers with multiple features, including target delivery triggered by environmental, pH, thermal responses, enhanced biocompatibility, and the ability to cross the blood-brain barrier. Chitosan (CS), a natural polysaccharide largely obtained from marine crustaceans, is a promising drug delivery vector for therapeutics and diagnostics, owing to its biocompatibility, biodegradability, low toxicity, and structural variability. This review describes various approaches to obtain novel CS derivatives, including their distinct advantages, as well as different forms of nanomaterials recently developed from CS. The advanced applications of CS-based nanomaterials are presented here in terms of their specific functions. Recent studies have proven that nanotechnology combined with CS and its derivatives could potentially circumvent obstacles in the transport of drugs thereby improving the drug efficacy. CS-based nanomaterials have been shown to be highly effective in targeted drug therapy.

Synthesis of magnetic cytosine-imprinted chitosan nanoparticles

Molecularly imprinted polymer nanoparticles incorporating magnetic nanoparticles (MNPs) have been investigated for their selective adsorption properties. Here we describe the synthesis and characterization of magnetic cytosine-imprinted chitosan nanoparticles (CIPs) for gene delivery. In particular, CIPs carrying the mammalian expression plasmid of enhanced green fluorescent protein were prepared by the co-precipitation of MNPs, chitosan and a template nucleobase (cytosine). The results show that the selective reabsorption of cytosine to magnetic CIPs was at least double that of non-imprinted polymers and other nucleobases (such as adenine and thymine). The gene carrier CIPs were used for the transfection of human embryonic kidney 293 cells showing dramatic increase their efficiency with that of conventional chitosan nanoparticles. Furthermore, the gene carrier magnetic CIPs also exhibit low toxicity compared to that of commercially available cationic lipids.