Application of magnetic hydroxyapatite nanoparticles for solid phase extraction of plasmid DNA

Composites of hydroxyapatite and their application in adsorption, medicine and as catalysts

Composites of hydroxyapatite, recognized by its peculiar crystal architecture and distinctive attributes showcased the potential in adsorbing heavy metal ions and radioactive elements as well as selected organic substances. In this paper, the intrinsic mechanism of adsorption by composites hydroxyapatite was proved for the first time. Subsequently, selectivity and competitiveness of composites of hydroxyapatite for a variety of environments containing various interferences from cations, anions, and organic molecules are elucidated. Next, composites of hydroxyapatite were further categorized according to their morphological dimensions. Adsorption properties and intrinsic mechanisms were investigated based on different morphologies. It was shown that although composites of hydroxyapatite were characterized by excellent adsorption capacity and cost-effectiveness, their application is often challenging due to inherent fragility and agglomeration, technical problems required for their handling as well as difficulty in recycling. Finally, to address these issues, the paper discusses the tendency of hydroxyapatite composites to adsorb heavy metal ions and radioactive elements as well as the limitations of their applications. Summarizing the limitations and future directions of modification of HAP in the field of heavy metal ions and different substances contamination abatement, the paper provides insightful perspectives for its gradual improvement and rational application.

DNA purification using a novel γ-Fe2O3/PEDOT hybrid nanocomposite

We report the synthesis and characterization of a new hybrid magnetic composite formed by the enveloping of magnetic iron oxide nanoparticles (γ-NP) with chains of the conductive polymer PEDOT, and its use for the efficient separation of DNA molecules from complex biological samples, allowing the high yield separation of a pure and high-quality DNA fraction. The successful formation of the γ-NP/PEDOT composite was confirmed by Fourier transform infrared spectroscopy, scanning electron microscopy, UV visible spectroscopy (UV-Vis), and magnetic hysteresis loop measurements. The nanocomposites showed an excellent capacity of DNA adsorption (Q_e ∼ 248 mg/g) in a model system consisting of salmon sperm DNA. When the γ-NP/PEDOT was used in protocols to extract the DNA from complex samples, the corresponding yield was in the range of 6.4 μg (blood) and 7.3 μg (bacteria), as evaluated quality by UV-Vis, PCR analysis, and electrophoresis assays. We also established that the captured DNA does not need to be detached from the nanocomposite for use as seeding material in PCR amplification experiments. These results and the simplicity of the protocols indicate that the γ-NP/PEDOT composite is a promising DNA absorbent, being competitive with the commercially available magnetic purification kits.

Hydroxyapatite with magnetic core: Synthesis methods, properties, adsorption and medical applications

This review presents the actual state of knowledge and recent research results on the magnetic composite synthesized from iron oxide (γ-Fe₂O₃ or Fe₃O₄) and hydroxyapatite. It can be obtained applying some methods, i.e. chemical precipitation, hydrothermal, sol-gel, and biomimetic or combined techniques which exhibit characteristic properties affecting the form of the prepared product. More specific details are discussed in this paper. A comparison of the discussed synthesis methods is presented. On the basis of selected publications, a comparison of the results of the analysis by XRD, FTIR, SEM and EDX methods for hydroxyapatite with a magnetic core was also presented. Moreover, the characteristics large adsorption capacity and specific area allow employing nanocomposites as adsorbents particularly in removal of toxic metal ions. Nowadays this issue is extremely vital due to large amounts of pollutants in the environment and greater ecological awareness of people. Moreover, magnetic hydroxyapatite can be also applied as a catalyst in various syntheses or oxidation reactions as well as in medicine in magnetic resonance imaging, hyperthermia treatment, drug delivery and release, bone regeneration or cell therapy.

Nano-hydroxyapatite/polyaniline composite as an efficient sorbent for sensitive determination of the polycyclic aromatic hydrocarbons in air by a needle trap device

Hydroxyapatite is a readily available, inexpensive, environmentally friendly adsorbent with high adsorption capacity. In this study, a polyaniline-doped nano-hydroxyapatite (PANI@HA) adsorbent was synthesized and employed in a needle trap device for the extraction of polycyclic aromatic hydrocarbons such as naphthalene, fluoranthene, benzo[a]anthracene, phenanthrene, and benzo[a]pyrene for the first time. The synthesized adsorbent was characterized by X-ray diffraction, field emission scanning electron microscopy, and Fourier-transform infrared spectroscopy analysis. Initially, effective variables such as the carryover effect, storage time, accuracy, and precision of the method were examined in the laboratory. The desorption conditions were optimized using the response surface methodology and central composite design methods. From the standpoint of quantitative parameters, the limit of detection and limit of quantitation were determined to be between 0.001 and 0.003 and 0.021 and 0.051 ng mL-1, respectively, which indicates the high sensitivity of the proposed method. Additionally, no significant changes were detected after storage of analytes inside the needle at 4 °C after 60 days. The results of this study also provide a high correlation between the results of sampling with needles containing PANI@HA and with XAD-2 adsorbent tubes (standard NIOSH 5115 method) (R 2 = 0.98). Finally, the proposed method was successfully employed in the extraction and determination of polycyclic aromatic hydrocarbons in field (real) samples. In general, it can be concluded that a needle packed with PANI@HA is a reliable and high-performance method for sampling polycyclic aromatic hydrocarbons compared to the NIOSH method.

Folate conjugation improved uptake and targeting of porous hydroxyapatite nanoparticles containing epirubicin to cancer cells

As hydroxyapatite (HAp) with the hexagonal crystal structure is biocompatible and bioactive. In the present study, HAp nanoparticles were synthesized and functionalized with polyethylene glycol and folic acid. The anticancer drug, epirubicin, was loaded to the folic acid-conjugated polyethylene glycol-coated HAp (FA-PEG-HAp) nanoparticles. The prepared nanoparticles were used for in vitro and in vivo experiments. Particle size analyzer showed that the hydrodynamic size of PEG-HAp and FA-PEG-HAp nanoparticles was 150.3 ± 1.5 nm and 217.2 ± 14.9 nm, respectively. The release behavior of epirubicin from nanoparticles showed an increase in the rate of release in acidic pH. The released drug in acidic pH was 2.5 fold more than pH 7.4. The results of in vitro study indicated an increase in cellular uptake of nanoparticles due to folate ligand. In vivo treatment with both PEG-HAp and FA-PEG-HAp nanoparticles had notably higher inhibition efficacy towards tumor growth than free epirubicin. In conclusion, folate conjugation provided higher uptake and better targeting of hydroxyapatite nanoparticles to cancer cells.

Magnetic hydroxyapatite: a promising multifunctional platform for nanomedicine application

In this review, specific attention is paid to the development of nanostructured magnetic hydroxyapatite (MHAp) and its potential application in controlled drug/gene delivery, tissue engineering, magnetic hyperthermia treatment, and the development of contrast agents for magnetic resonance imaging. Both magnetite and hydroxyapatite materials have excellent prospects in nanomedicine with multifunctional therapeutic approaches. To date, many research articles have focused on biomedical applications of nanomaterials because of which it is very difficult to focus on any particular type of nanomaterial. This study is possibly the first effort to emphasize on the comprehensive assessment of MHAp nanostructures for biomedical applications supported with very recent experimental studies. From basic concepts to the real-life applications, the relevant characteristics of magnetic biomaterials are patented which are briefly discussed. The potential therapeutic and diagnostic ability of MHAp-nanostructured materials make them an ideal platform for future nanomedicine. We hope that this advanced review will provide a better understanding of MHAp and its important features to utilize it as a promising material for multifunctional biomedical applications.

Designed Synthesis of Nanostructured Magnetic Hydroxyapatite Based Drug Nanocarrier for Anti-Cancer Drug Delivery toward the Treatment of Human Epidermoid Carcinoma

Superparamagnetic Fe₃O₄ nanoparticles on hydroxyapatite nanorod based nanostructures (Fe₃O₄/HAp) were synthesized using hydrothermal techniques at 180 °C for 12 h and were used as drug delivery nanocarriers for cancer cell therapeutic applications. The synthesized Fe₃O₄/HAp nanocomposites were characterized by X-ray diffraction analysis (XRD), Field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET)-analysis, and vibrating sample magnetometry (VSM). The morphologies of the Fe₃O₄/HAp nanocomposites show 15 nm Fe₃O₄ nanoparticles dispersed in the form of rods. The BET result shows that the synthesized samples have a high specific surface area of 80 m² g-1 with mesoporous structures. Magnetic measurements revealed that the sample has high saturation magnetization of 18 emu/g with low coercivity. The Fe₃O₄/HAp nanocomposites had a large specific surface area (SSA), high mesoporous volume, and good magnetic property, which made it a suitable nanocarrier for targeted drug delivery systems. The chemotherapeutic agent, andrographolide, was used to investigate the drug delivery behavior of the Fe₃O₄/HAp nanocomposites. The human epidermoid skin cancer cells (A431) were used as the model targeting cell lines by treating with andrographolide loaded Fe₃O₄/HAp nanosystems and were further evaluated for their antiproliferative activities and the induction of apoptosis. Also, the present nanocomposite shows better biocompatibility, therefore it can be used as suitable drug vehicle for cancer therapy applications.

Facile in situ growth of Fe3O4 nanoparticles on hydroxyapatite nanorods for pH dependent adsorption and controlled release of proteins

The magnetic hydroxyapatite nanostructures were prepared by hydrothermal technique and studied their protein adsorption and in vitro cytotoxicity in humen MGC-803 cell.

Sonoporation increases therapeutic efficacy of inducible and constitutive BMP2/7 in vivo gene delivery

An ideal novel treatment for bone defects should provide regeneration without autologous or allogenous grafting, exogenous cells, growth factors, or biomaterials while ensuring spatial and temporal control as well as safety. Therefore, a novel osteoinductive nonviral in vivo gene therapy approach using sonoporation was investigated in ectopic and orthotopic models. Constitutive or regulated, doxycycline-inducible, bone morphogenetic protein 2 and 7 coexpression plasmids were repeatedly applied for 5 days. Ectopic and orthotopic gene transfer efficacy was monitored by coapplication of a luciferase plasmid and bioluminescence imaging. Orthotopic plasmid DNA distribution was investigated using a novel plasmid-labeling method. Luciferase imaging demonstrated an increased trend (61% vs. 100%) of gene transfer efficacy, and micro-computed tomography evaluation showed significantly enhanced frequency of ectopic bone formation for sonoporation compared with passive gene delivery (46% vs. 100%) dependent on applied ultrasound power. Bone formation by the inducible system (83%) was stringently controlled by doxycycline in vivo, and no ectopic bone formation was observed without induction or with passive gene transfer without sonoporation. Orthotopic evaluation in a rat femur segmental defect model demonstrated an increased trend of gene transfer efficacy using sonoporation. Investigation of DNA distribution demonstrated extensive binding of plasmid DNA to bone tissue. Sonoporated animals displayed a potentially increased union rate (33%) without extensive callus formation or heterotopic ossification. We conclude that sonoporation of BMP2/7 coexpression plasmids is a feasible, minimally invasive method for osteoinduction and that improvement of bone regeneration by sonoporative gene delivery is superior to passive gene delivery.

Extraction of three nitrophenols using polypyrrole-coated magnetic nanoparticles based on anion exchange process

In this research, the applicability of polypyrrole-coated Fe3O4 nanoparticles (Fe3O4@PPy NPs) as an anion exchange magnetic nanosorbent is demonstrated. For this purpose, three nitrophenols were selected as models which are acidic compounds with low logP values and their extraction in neutral form (only based on hydrophobic interactions) is difficult. The extracted nitrophenols were separated and determined by high-performance liquid chromatography-UV detection. The size, morphology and surface coating of synthesized Fe3O4@PPy NPs have been characterized via different techniques such as Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy and thermo-gravimetric analysis. The important parameters influencing the extraction efficiency were studied and optimized. Under the optimum extraction conditions (300mL sample solution with pH 10, extraction and desorption times of 10 and 2min, respectively, 500μL of 0.1M HNO3 in acetonitrile as eluent, and 40mg of adsorbent), a linear range between 0.75 and 100μgL(-1) (R(2)>0.997), and limits of detection ranging from 0.3 to 0.4μgL(-1) were obtained. Preconcentration factors in the range of 125-180 were achieved and relative standard deviations (RSDs%) were less than 4.9 (n=4) for the three nitrophenols. The analytical method was successfully applied for environmental water samples such as tap water, rain water and river water. The recoveries varied within the range of 84-109% confirming good performance of the method in various waters samples. The results showed that the proposed method is a rapid, convenient and feasible technique for determination of nitrophenols in aqueous samples.