Magnetic carbon nanotubes (MCNTs) have been widely studied for their potential applications in medicine, diagnosis, cell biology, analytical chemistry, and environmental technology. Introduction of MCNTs paved the way for the emergence of new approaches in nanobiotechnology and biomedicine as a result of their multifarious properties embedded within either the carbon nanotubes (CNTs) or magnetic parts. Numerous preparation techniques exists for functionalizing CNTs with magnetic nanoparticles, and these versatile strategies lay the ground for the generation of novel and versatile systems which are applicable to many industries and biological areas. Here, we review and discuss the recent papers dealing with MCNTs and their application in biomedical and industrial fields.

Magnetic nanoparticles have properties that cause to apply them in cancer therapy and vehicles for the delivery of drugs such as 5FU, especially when they are modified with biocompatible copolymers. The aim of this study is to modify superparamagnetic iron oxide nanoparticles (SPIONPs) with PCL-PEG-PCL copolymers and then utilization of these nanoparticles for encapsulation of anticancer drug 5FU. The ring-opening polymerization (ROP) was used for the synthesis of PCL-PEG-PCL copolymer by ε-caprolactone (PCL) and polyethylene glycol (PEG2000). We used the double emulsion method (water/oil/water) to prepare 5FU-encapsulated Fe₃O₄ magnetic nanoparticles modified with PCL-PEG-PCL copolymer. Chemical structure and magnetic properties of 5FU-loaded magnetic-polymer nanoparticles were investigated systematically by employing FT-IR, XRD, VSM and SEM techniques. In vitro release profile of 5FU-loaded NPs was also determined. The results showed that the encapsulation efficiency value for nanoparticles were 90%. Moreover, the release of 5FU is significantly higher at pH 5.8 compared to pH 7.4. Therefore, these nanoparticles have sustained release and can apply for cancer therapy.

In the current study, we proposed a facile method for fabrication of multifunctional pH- and thermo-sensitive magnetic nanocomposites (MNCs) as a theranostic agent for using in targeted drug delivery and magnetic resonance imaging (MRI). To this end, we decorated Fe₃O₄ magnetic nanoparticles (MNPs) with N,N-dimethylaminoethyl methacrylate (DMAEMA) and N-isopropylacrylamide (NIPAAm), best known for their pH- and thermo-sensitive properties, respectively. We also conjugated mesoporous silica nanoparticles (MSNs) to polymer matrix acting as drug container to enhance the drug encapsulation efficacy. Methotroxate (MTX) as a model drug was successfully loaded in MNCs (M-MNCs) via surface adsorption onto MSNs and electrostatic interaction between drug and carrier. The pH- and temperature-triggered release of MTX was concluded through the evaluation of in vitro release at both physiological and simulated tumor tissue conditions. Based on in vitro cytotoxicity assay results, M-MNCs significantly revealed higher antitumor activity compared to free MTX. In vitro MR susceptibility experiment showed that M-MNCs relatively possessed high transverse relaxivity (r₂) of about 0.15 mM^-1·ms^-1 and a linear relationship between the transverse relaxation rate (R₂) and the Fe concentration in the M-MNCs was also demonstrated. Therefore, the designed MNCs can potentially become smart drug carrier, while they also can be promising MRI negative contrast agent.

Cationic polymers are characterized as the macromolecules that possess positive charges, which can be either inherently in the polymer side chains and/or its backbone. Based on their origins, cationic polymers are divided in two category including natural and synthetic, in which the possessed positive charges are as result of primary, secondary or tertiary amine functional groups that could be protonated in particular situations. Cationic polymers have been employed commonly as drug delivery agents due to their superior encapsulation efficacy, enhanced bioavailability, low toxicity and improved release profile. In this paper, we focus on the most prominent examples of cationic polymers which have been revealed to be applicable in drug delivery systems and we also discuss their general synthesis and surface modification methods as well as their controlled release profile in drug delivery.

The synthesis of different kinds of magnetic nanoparticles (MNPs) has attracted much attention. During the last few years, a large portion of the articles published about MNPs have described efficient routes to attain shape-controlled and highly stable MNPs with narrow size distribution. In this review, we have reported several popular methods including co-precipitation, microemulsion, thermal decomposition, solvothermal, sonochemical, microwave-assisted, chemical vapor deposition, combustion, carbon arc, and laser pyrolysis, for the synthesis of magnetic nanoparticles.

Generally, carbon nanoparticles with a size of 10 nm (or less) are called carbon quantum dots (CQDs, C-dots or CD), which have created huge excitement due to their advantages in chemical inertness, high water solubility, excellent biocompatibility, resistance to photobleaching and various optical superiority. In this article, we describe the recent advancements in the area of CQDs; concentrating on their synthesis techniques, size control, surface modification approaches, optical properties, luminescent mechanism, and their applications in bioimaging, biosensing, drug delivery and catalysis.

Aim

Dendrimers dendritic structural design holds vast promises, predominantly for drug delivery, owing to their unique properties. Dendritic architecture is widespread topology found in nature and offers development of specific properties of chemical substances. Dendrimers are an ideal delivery vehicle candidate for open study of the effects of polymer size, charge, and composition on biologically relevant properties such as lipid bilayer interactions, cytotoxicity, bio-distribution, internalization, blood plasma retention time, and filtration. This article reviews role of dendrimers in advanced drug delivery and biomedical applications.

Objective

The purpose of this study was to investigate the intra-rater reliability and validity of a designed load cell setup for the measurement of back extensor muscle force and endurance.

Participants

The study sample included 19 older women with hyperkyphosis, mean age 67.0 ± 5.0 years, and 14 older women without hyperkyphosis, mean age 63.0 ± 6.0 years.

Methods

Maximum back extensor force and endurance were measured in a sitting position with a designed load cell setup. Tests were performed by the same examiner on two separate days within a 72-hour interval. The intra-rater reliability of the measurements was analyzed using intraclass correlation coefficient (ICC), standard errors of measurement (SEM), and minimal detectable change (MDC). The validity of the setup was determined using Pearson correlation analysis and independent t-test.

Results

Using our designed load cell, the values of ICC indicated very high reliability of force measurement (hyperkyphosis group: 0.96, normal group: 0.97) and high reliability of endurance measurement (hyperkyphosis group: 0.82, normal group: 0.89). For all tests, the values of SEM and MDC were low in both groups. A significant correlation between two documented forces (load cell force and target force) and significant differences in the muscle force and endurance among the two groups were found.

Conclusion

The measurements of static back muscle force and endurance are reliable and valid with our designed setup in older women with and without hyperkyphosis.