Nanobiomedicine最新文献

The arena of biomedical science has long been in quest of innovative mediums for diagnostic and therapeutic applications. The latest being the use of nanomaterials for such applications, thereby giving rise to the branch of nanomedicine. Halloysite nanotubes (HNTs) are naturally occurring tubular clay nanomaterials, made of aluminosilicate kaolin sheets rolled several times. The aluminol and siloxane groups on the surface of HNT facilitate the formation of hydrogen bonding with the biomaterials onto its surface. These properties render HNT pivotal in diverse range of applications, such as in environmental sciences, waste-water treatment, dye removal, nanoelectronics and fabrication of nanocomposites, catalytic studies, as glass coatings or anticorrosive coatings, in cosmetics, as flame retardants, stimuli response, and forensic sciences. The specific properties of HNT also lead to numerous applications in biomedicine and nanomedicine, namely drug delivery, gene delivery, tissue engineering, cancer and stem cells isolation, and bioimaging. In this review, recent developments in the use of HNT for various nanomedicinal applications have been discussed.

Drug delivery to the brain is challenging because of the low permeability of blood-brain barrier, and therefore, optimum concentration of chemotherapeutics in the target area specifically for glioblastoma, an aggressive brain tumor, opens a new path of research. To achieve the goal, the oral alkylating agent temozolomide was incorporated into niosomes, and the surface was modified with chlorotoxin, a small 36 amino acid peptide discovered from the venom of scorpion Leiurus quinquestriatus. Active targeting using nanosized particles facilitates an increase in the accumulation of drugs in the cerebri by 3.04-folds. Temozolomide-loaded niosomes were prepared using conventional thin-film hydration method and characterized. Niosomes coated with chlorotoxin were produced with the size of 220 ± 1.45 nm with an entrapment efficiency of 79.09 ± 1.56%. Quantitative tissue distribution studies indicate enhanced permeation of the drug into the brain because of surface modification with less deposition in the highly perfused organs.

Tendon injuries can be difficult to heal and have high rates of relapse due to stress concentrations caused by scar formation and the sutures used in surgical repair. Regeneration of the tendon/ligament-to-bone interface is critical to provide functional graft integration after injury. The objective of this study is to recreate the tendon-to-bone interface using a gradient scaffold which is fabricated by a one-station electrospinning process. Two cell phenotypes were grown on a poly-ε-caprolactone nanofiber scaffold which possesses a gradual transition from random to aligned nanofiber patterns. We assessed the effects of the polymer concentration, tip-to-collector distance, and electrospinning time on the microfiber diameter and density. Osteosarcoma and fibroblast cells were seeded on the random and aligned sections of scaffolds, respectively. A random-to-aligned cocultured tissue interface which mimicked the native transition in composition of enthesis was created after 96 h culturing. The results showed that the microstructure gradient influenced the cell morphology, tissue topology, and promoted enthesis formation. This study demonstrates a heterogeneous nanofiber scaffold strategy for interfacial tissue regeneration. It provides a potential solution for mimicking transitional interface between distinct tissues, and can be further developed as a heterogeneous cellular composition platform to facilitate the formation of multi-tissue complex systems.

A new class of biologically active polymer nanocomposites based on polyvinyl alcohol and reinforced mixed graphene/carbon nanotube as carbon-based nanofillers with a general abbreviation (polyvinyl alcohol/mixed graphene-carbon nanotubes) has been successfully synthesized by an efficient solution mixing method with the help of ultrasonic radiation. Mixed graphene and carbon nanotubes ratio has been prepared (50%:50%) wt by wt. Different loading of mixed graphene-carbon nanotubes (2, 5, 10, 15, and 20 wt%) were added to the host polyvinyl alcohol polymer. In this study, polyvinyl alcohol/mixed graphene-carbon nanotubes_a-e nanocomposites were characterized and analyzed by X-ray diffraction, Fourier transform infrared, scanning electron microscopy, transmission electron microscopy, and the thermal stability was measured by thermogravimetric analysis and derivative thermal gravimetric. Fourier transform infrared and X-ray diffraction spectra proved the addition of mixed graphene-carbon nanotubes into polyvinyl alcohol matrix. X-ray diffraction patterns for these nanocomposites showed 2θ = 19.35° and 40° due to the crystal nature of polyvinyl alcohol in addition to 2θ = 26.5° which attributed to the graphite plane of carbon-based nanofillers. Thermal stability of polyvinyl alcohol/mixed graphene-carbon nanotubes nanocomposites was enhanced comparing with pure polyvinyl alcohol. The main degradation step ranged between 360° and 450°C. Moreover, maximum composite degradation temperature has appeared at range from 285°C to 267°C and final composite degradation temperature (FCDT) displayed at a temperature range of 469-491°C. Antibacterial property of polyvinyl alcohol/mixed graphene-carbon nanotubes_a-e nanocomposites were tested against Escherichia coli bacteria using the colony forming units technique. Results showed an improvement of antibacterial property. The rate percentages of polyvinyl alcohol/mixed graphene-carbon nanotubes_b, polyvinyl alcohol/mixed graphene-carbon nanotubes_c, and polyvinyl alcohol/mixed graphene-carbon nanotubes_d nanocomposites after 24 h are 6%, 5%, and 7% respectively. However, polyvinyl alcohol/mixed graphene-carbon nanotubes_e nanocomposite showed hyperactivity, where its reduction percentage remarkably raised up to 100% which is the highest inhibition rate percentage. In addition, polyvinyl alcohol and polyvinyl alcohol/graphene-carbon nanotubes_a-d showed colony forming units values/ml 70 × 10⁶ and 65 ± 2 × 10⁶ after 12 h. After 24 h, the colony forming units values/ml were in the range of 86 × 10⁶-95 × 10⁶.

Composite, multifunctional fine particles are likely to be at the frontier of materials science in the foreseeable future. Here we present a submicron composite particle that mimics the stratified structure of the Earth by having a zero-valent iron core, a silicate/silicide mantle, and a thin carbonaceous crust resembling the biosphere and its biotic deposits. Particles were formulated in a stable colloidal form and made to interact with various types of healthy and cancer cells in vitro. A selective anticancer activity was observed, promising from the point of view of the intended use of the particles for tumor targeting across the blood-brain barrier. As an extension of the idea underlying the fabrication of a particle mimicking the planet Earth, we propose a new field of mimetics within materials science: astromimetics. The astromimetic approach in the context of materials science consists of the design of particles after the structure of celestial bodies. With Earth being the most chemically diverse and fertile out of all the astral bodies known, it is anticipated that the great majority of astromimetic material models will fall in the domain of geo-inspired ones.

Prof. Mostafa A El-Sayed, Regents' Professor and Julius Brown Chair at the Department of Chemistry and Biochemistry in the Georgia Institute of Technology, has well over 755 publications in a variety of fields ranging from the areas of photochemistry, to ultrafast laser spectroscopy, to time-resolved Raman spectroscopy, to formulating what is known as the El-Sayed Rule. One of the main subject areas of Prof. El-Sayed's research interests is Nanobiomedicine; he is one of the pioneers in this field. We are sending this perspective in celebration of Prof. El-Sayed's 85th birthday on May 8, 2018. We would like to encourage the science community to submit their research to Nanobiomedicine. In brief, Prof. Mostafa El-Sayed has demonstrated that using gold nanoparticles and irradiating them with laser beams can kill cancerous cells without harming the surrounding healthy tissues. The concept of photothermal therapy, that he introduced, had been successful in culture cells and living animal models.

The research for new in vitro screening tools for predictive metabolic profiling of drug candidates is of major interest in the pharmaceutical field. The main motivation is to avoid late rejection in drug development and to deliver safer drugs to the market. Thanks to the superparamagnetic properties of iron oxide nanoparticles, a flow bioreactor has been developed which is able to perform xenobiotic metabolism studies. The selected cell line (HepaRG) maintained its metabolic competencies once iron oxide nanoparticles were internalized. Based on magnetically trapped cells in a homemade immobilization chamber, through which a flow of circulating phase was injected to transport nutrients and/or the studied xenobiotic, off-line and online (when coupled to a high-performance liquid chromatography chain) metabolic assays were developed using diclofenac as a reference compound. The diclofenac demonstrated a similar metabolization profile chromatogram, both with the newly developed setup and with the control situation. Highly versatile, this pioneering and innovative instrumental design paves the way for a new approach in predictive metabolism studies.

In the two decades after 1990, the rates of child and maternal mortality dropped by over 40% and 47%, respectively. Despite these improvements, which are in part due to increased access to medical technologies, profound health disparities exist. In 2015, a child born in a developing region is nearly eight times as likely to die before the age of 5 than one born in a developed region and developing regions accounted for nearly 99% of the maternal deaths. Recent developments in nanotechnology, however, have great potential to ameliorate these and other health disparities by providing new cost-effective solutions for diagnosis or treatment of a variety of medical conditions. Affordability is only one of the several challenges that will need to be met to translate new ideas into a medical product that addresses a global health need. This article aims to describe some of the other challenges that will be faced by nanotechnologists who seek to make an impact in low-resource settings across the globe.

In this study, tanshinone was extracted from Salvia miltiorrhiza. To improve the utilization and the dissolution of the drug, the tanshinone extractions were prepared at a pharmaceutical nanoscale and in the nanometer range of 100-200 nm. Then, the rate of tumor inhibition and the activity of antioxidant system and the thymus/spleen indices were investigated to find the antitumor effect of nanoparticles of tanshinone in cervical carcinoma-bearing mice. Our data suggest that tanshinone inhibits cervical tumor growth and the rates of tumor inhibition of all drug groups were more than 45%. The highest rate was 70.88% in the high dose of nanoscale tanshinone group. The activities of superoxide dismutase were higher in drug groups than in the model control group, and the concentrations of malondialdehyde were significantly lower. These findings suggested that tanshinone enhance the superoxide dismutase activity of the mice and decrease the malondialdehyde content. It may be one of the mechanisms of antitumor effect of tanshinone. The thymus index and spleen index were higher than normal control or model control. These data suggested that tanshinone also enhanced the immune system of mice.