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Topic Review
RNAi Delivery
Bone-related injury and disease constitute a significant global burden both socially and economically. Current treatments have many limitations and thus the development of new approaches for bone-related conditions is imperative. Gene therapy is an emerging approach for effective bone repair and regeneration, with notable interest in the use of RNA interference (RNAi) systems to regulate gene expression in the bone microenvironment. Calcium phosphate nanoparticles represent promising materials for use as non-viral vectors for gene therapy in bone tissue engineering applications due to their many favorable properties, including biocompatibility, osteoinductivity, osteoconductivity, and strong affinity for binding to nucleic acids. However, low transfection rates present a significant barrier to their clinical use. This article reviews the benefits of calcium phosphate nanoparticles for RNAi delivery and highlights the role of surface functionalization in increasing calcium phosphate nanoparticles stability, improving cellular uptake and increasing transfection efficiency. Currently, the underlying mechanistic principles relating to these systems and their interplay during in vivo bone formation is not wholly understood. Furthermore, the optimal microRNA targets for particular bone tissue regeneration applications are still unclear. Therefore, further research is required in order to achieve the optimal calcium phosphate nanoparticles-based systems for RNAi delivery for bone tissue regeneration.
  • 805
  • 17 Jun 2022
Topic Review
Synthesis of Piperazines by C-H Functionalization
Piperazine ranks as the third most common nitrogen heterocycle in drug discovery, and it is the key component of several blockbuster drugs, such as Imatinib (also marketed as Gleevec) or Sildenafil, sold as Viagra. 
  • 804
  • 22 Oct 2021
Topic Review
Nitration of Proteins/Lipids/DNA by Peroxynitrite Derivatives
In recent years, much interest has been generated by the idea that nitrosative stress plays a role in the aetiology of human diseases, such as atherosclerosis, inflammation, cancer, and neurological diseases. The chemical changes mediated by reactive nitrogen species (RNS) are detrimental to cell function, because they can cause nitration, which can alter the structures of cellular proteins, DNA, and lipids, and hence, impair their normal function. One of the most potent biological nitrosative agents is peroxynitrite (ONOO−), which is produced when nitric oxide (•NO) and superoxide (•O2−) are combined at extremely rapid rates. Considering the plethora of oxidations by peroxynitrite, this makes peroxynitrite the most prevalent nitrating species responsible for protein, DNA, and lipids nitration in vivo. There is biochemical evidence to suggest that the interactions of the radicals NO and superoxide result in the formation of a redox system, which includes the reactions of nitrosation and nitration, and is a component of the complex cellular signalling network. However, the chemistry involved in the nitration process with peroxynitrite derivatives is poorly understood, particularly for biological molecules, such as DNA, proteins, and lipids.
  • 804
  • 27 Sep 2022
Topic Review
Strategies for Improving Cell-Penetrating Peptides Stability and Delivery
Peptides play an important role in many fields, including immunology, medical diagnostics, and drug discovery, due to their high specificity and positive safety profile. However, for their delivery as active pharmaceutical ingredients, delivery vectors, or diagnostic imaging molecules, they suffer from two serious shortcomings: their poor metabolic stability and short half-life. Major research efforts are being invested to tackle those drawbacks, where structural modifications and novel delivery tactics have been developed to boost their ability to reach their targets as fully functional species.
  • 804
  • 04 Nov 2022
Topic Review
Indigo for Non-Toxic and Ecological Gliding Surfaces
The biogenic substance E-indigo can form supramolecular, hydrophobic structures using self-organization. These structures show a low coefficient of friction as a gliding layer against polar surfaces. The formation of primary particles with platelet morphology based on hydrogen-bonded E-indigo molecules is ideal to produce the gliding layer. Structures with excellent gliding properties on ice, snow, and water can be achieved by means of directed friction and high pressure, as well as through tempering. The resulting hard, thin gliding layer of E-indigo does not easily absorb dirt and, thus, prevents a rapid increase in friction. Field tests on snow, with cross-country skis, have shown promising results in comparison to fluorinated and non-fluorinated waxes. Based on quantitative structure–activity relationship (QSAR) data for E-indigo, and its isomers and tautomers, it has been demonstrated that both the application and abrasion of the thin indigo layers are harmless to health, and are ecologically benign and, therefore, sustainable.
  • 804
  • 21 Feb 2022
Topic Review
Nutraceutical Curcumin
Curcumin is a principal bioactive phenolic compound of the spice turmeric, in regard to various human and animal herpesvirus infections and inflammation connected with these diseases. Curcumin was explored with potent antiherpetic actions against herpes simplex virus type 1 and type 2, human cytomegalovirus, Kaposi’s sarcoma-associated herpesvirus, Epstein–Barr virus, bovine herpesvirus 1, and pseudorabies virus. 
  • 804
  • 07 Mar 2021
Topic Review
Extracellular Vesicles Analysis
Recently, extracellular vesicles (EVs) and their contents have been revealed to play crucial roles in the intrinsic intercellular communications and have received extensive attention as next-generation biomarkers for diagnosis of diseases such as cancers. However, due to the structural nature of the EVs, the precise isolation and characterization are extremely challenging. To this end, tremendous efforts have been made to develop bionano sensors for the precise and sensitive characterization of EVs from a complex biologic fluid.
  • 804
  • 27 Aug 2020
Topic Review
Alumina Nanocomposite
Although pure titanium and titanium alloys are highly biosafe, there are many reports of patients with metal allergies caused by titanium. In addition, it was used as a prosthesis in the oral cavity, such as the black triangle in which the gingiva turns black due to the gradual elution and deposition of metal ions in the titanium alloy, and the black margin generated when the gingiva lowers and the metal part is exposed. In some cases, there are also aesthetic issues.Zirconia is attracting attention as an alternative material to such problems. Zirconia is excellent in aesthetics and biosafety, and with the progress of CAD / CAM technology, its application in various applications has begun, and yttria-stable zirconia has already been put into practical use as a dental implant.However, yttria-stabilized zirconia, which is generally used as dental ceramics, is more brittle than metals such as titanium and has less bending properties, so there is a risk of breakage. Although yttria-stable zirconia is harder than metal, it is brittle once it is distorted, and it is a technical issue that the strength decreases when low-temperature deterioration occurs due to phase transition due to long-term use in a wet state such as in the oral cavity.On the other hand, ceria-stable zirconia-alumina composite ceramics have the same hardness as yttria-stable zirconia, and also have extremely excellent toughness, eliminating the weaknesses of ceramics such as brittleness and low-temperature deterioration in wet conditions. It is attracting attention as a ceramic.This ceramic has a nano-composite structure in which nano-sized alumina particles are incorporated into ceria-stable zirconia particles, and nano-sized ceria-stable zirconia particles are inter-dispersed in the alumina particles. , Nano zirconia). Nano zirconia has a high bending strength equivalent to that of general zirconia, and has a very high fracture toughness of 3 to 5 times that of general zirconia. Due to its high toughness as well as its strength, it is expected to be used in implan.However, nanozirconia is inferior in bone formation after implant placement compared to titanium, so surface modification is required for application as a medical device. So far, surface modification of nanozirconia has been investigated by concentrated alkali treatment, etc., but it is equivalent to titanium or titanium alloy, although it has a certain effect on the initial attachment of bone marrow cells or the induction of differentiation into hard tissue. Biocompatibility has not been achieved.
  • 804
  • 26 Oct 2020
Topic Review
Electric Double Layer Structure
The electric double layer (EDL) is the most important electrochemical and heterogeneous catalysis region. Because of it, its modeling and investigation are something that can be found in the literature for a long time. However, it is still something in debate, since nowadays a series of new techniques are available for the investigation of this interfacial area at the molecular level by experiments and simulations.
  • 803
  • 09 Dec 2022
Topic Review
Iron Oxide Nanoparticles in Biomedicine
Iron oxides are common natural compounds and can also easily be synthesized in the laboratory. There are 16 iron oxides, including oxides, hydroxides and oxide-hydroxides. These minerals are a result of aqueous reactions under various redox and pH conditions. They have the basic composition of Fe,O, and/or OH, but differ in the valency of iron and overall crystal structure. Some of the important iron oxides are goethite, akaganeite, lepidocrocite, magnetite and hematite.  Iron oxide (IO) nanoparticles consist of maghemite (y-Fe2O3) and/or magnetite (Fe3O4) particles with diameters ranging from 1 and 100 nanometer and find applications in magnetic data storage, biosensing, drug-delivery, etc. In nanoparticles (NPs), the surface area to volume ratio increases significantly. This allows a considerably higher binding capacity and excelent dispersibility of NPs in solutions. Magnetic NPs, with sizes between 2 and 20 nm display superparamagnetism, i.e. their magnetization is zero, in the absence of an external magnetic field and they can be magnetized by an extermal magnetic source. This property provides additional stability for magnetic nanparticles in solutions.  Because of their magnetic and superparamagnetic properties, iron oxide nanoparticles (IONPs) have many potential applications for medical use. The synthesis of these NPs has been the basis of many studies, each proposing different synthesis methods yielding nanostructures of different properties. The chemical, physical and magnetic properties of these nanostructures are examined to determine their possible application in mgnetic resonance imaging (MRI), contrast enhancement and thermal activation therapy. NPs characterization and demonstration of their potential uses pave  the way to the development of smart magnetic IONPs for targeted diagnostics and therapeutics of human diseases, including cancer and Alzheimer’s disease. Using the proprietary monoloyer polymer coating strategy, hydrophobic, organic ligand-coated IONPs have successfully been converted into water soluble, bio-accessible IONPs. Recent enhancement in the quality of both organic and water soluble IONPs opens avenues of opportunities for development of IO nanoparticles based applications, for example:  ·         As contrast agents for magnetic resonance imaging (MRI)  ·         As drug carriers for target specific drug delivery  ·         As gene carriers for gene therapy ·         As therapeutic agents for hyperthermia based cancer treatments ·         As magnetic sensing probes for in-vitro diagnostics (IVD) ·         As nanoadjuvant for vaccine and antibody production.  This growing portfolio of magnetic NPs excited us to offer a brief review on the biologically compatible IONPs synthesized by electrochemical deposition, and their potential use in biomedical application. 
  • 803
  • 21 Jan 2021
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