Adnan Nasir

The growing role of nanotechnology in combating infectious disease

The treatment and prevention of infectious diseases is a major part of both clinical and investigative medicine. As the use of conventional antibiotics rises, antimicrobial resistance patterns develop, necessitating the continuous need for newer and more effective therapies. Nanotechnology, defined as the production and application of materials in the nanoscale range (1-100nm), has been the focus of several investigations as a result of unique physical and chemical properties of nanomaterials. . Specifically, nanomaterials provide added benefits due to their small size; allowing for an increased ability to surpass most physiologic barriers and reach their intended targets, and high surface area-to-volume ratio, allowing for increased potential to interact with pathogen membranes and cell walls. This review focuses of the potential therapeutic and preventative applications of nanotechnology-based drug delivery systems in infectious disease.

Nanotechnology in Vaccine Development: A Step Forward

The study of nanotechnology for epicutaneous delivery of pharmaceuticals and vaccines is burgeoning. Topically applied nanomaterials have been shown to enter tape-stripped skin and reach draining lymph nodes in an inbred strain of mice. Nanomaterials in the form of plasmid DNA, proteins, and virus particles accumulate in hair follicles, diffuse via dendritic cells to draining lymph nodes, and elicit antigen-specific humoral and cell-mediated immunity. Topically immunized mice have also demonstrated resistance to infection with live virus. Advantages of nanotechnology include uniformity, reproducibility, and precision in the synthesis and manufacture of candidate compounds. Combined with novel pharmacokinetics and the possibility of targeted therapy, nanotechnology-based vaccines may prove superior to existing vaccines and have the potential to open therapeutic avenues for treating infectious disease and malignancy.

Nanotechnology and dermatology: Part II—risks of nanotechnology

0738 doi:1 ...from time to time, a high wind would blow across the desert, whipping up the sand, which swirled and eddied, a thick yellow cloud. It rendered visibility as poor as a thick London fog. It penetrated everywhere. One breathed sand, one swallowed it, ones eyes and ears and nose were filled with it. Ones hair was matted with sand. Ones face and arms were yellow and sore from the tiny gritty particles which penetrated the pores of the skin.

Polyglycolic acid microneedles modified with inkjet-deposited antifungal coatings

In this study, the authors examined use of piezoelectric inkjet printing to apply an antifungal agent, voriconazole, to the surfaces of biodegradable polyglycolic acid microneedles. Polyglycolic acid microneedles with sharp tips (average tip radius = 25 ± 3 μm) were prepared using a combination of injection molding and drawing lithography. The elastic modulus (9.9 ± 0.3 GPa) and hardness (588.2 ± 33.8 MPa) values of the polyglycolic acid material were determined using nanoindentation and were found to be suitable for use in transdermal drug delivery devices. Voriconazole was deposited onto the polyglycolic acid microneedles by means of piezoelectric inkjet printing. It should be noted that voriconazole has poor solubility in water; however, it is readily soluble in many organic solvents. Optical imaging, scanning electron microscopy, energy dispersive x-ray spectrometry, and Fourier transform infrared spectroscopy were utilized to examine the microneedle geometries and inkjet-deposited surface coatings. Furthermore, an in vitro agar plating study was performed on the unmodified, vehicle-modified, and voriconazole-modified microneedles. Unlike the unmodified and vehicle-modified microneedles, the voriconazole-modified microneedles showed antifungal activity against Candida albicans. The unmodified, vehicle-modified, and voriconazole-modified microneedles did not show activity against Escherichia coli, Pseudomonas aeruginosa, or Staphylococcus aureus. The results indicate that piezoelectric inkjet printing may be useful for loading transdermal drug delivery devices such as polyglycolic acid microneedles with antifungal pharmacologic agents and other pharmacologic agents with poor solubility in aqueous solutions.

Photonanodermatology: the interface of photobiology, dermatology and nanotechnology.

This review focuses on the optical properties of matter on the nanoscale and discusses some of their potential applications in dermatology. The applications will be divided into three main categories: those with consumer potential; those with diagnostic potential; and those with therapeutic potential.

Nanotechnology in Dermatology

Nanotechnology in dermatology , Nanotechnology in dermatology , کتابخانه مرکزی دانشگاه علوم پزشکی تهران

VEB4: Early zygotic mRNA expressed asymmetrically along the animal‐vegetal axis of the sea urchin embryo

We have analyzed a gene, designated VEB4, that is expressed transiently in very early blastulae of the sea urchin, Strongylocentrotus purpuratus. Sequence analysis of the complete open reading frame shows that VEB4 encodes an unusual, highly charged protein with a pl of 9.55. We show here that VEB4 mRNA accumulate in a spatial pattern that is indistinguishable from that of two other recently described genes encoding metallo‐endoproteases, SpAN, related to astacin and SpHE, the hatching enzyme (Reynolds et al. 1992). VEB4 and other members of this gene set encode the earliest strictly zygotic gene products that have been identified. The asymmetric accumulation of VEB4 mRNA in non‐vegetal blastomeres of the 16 cell embryo and their descendants reflects the animal‐vegetal maternal developmental axis.

The Skin Immune System

The skin is the largest organ in the body. It serves many functions, including thermoregulation, endocrine homeostasis, and transduction of environmental stimuli. The latter can be from simple registering of heat and cold to photoreception [1] or to the complex haptic processing required to read Braille. The skin actively and passively defends against chemical, thermal, electrical, radioactive, physical, and other environmental and microbial insults. The latter defenses fall under the broad purview of the skin immune system. Nanotechnology exploits the unique properties of matter on the nanoscale to selectively target the skin immune system, either for the purposes of augmenting immunity, in the case of immunodeficiency or in generating an immune response against a tumor or pathogen, or for the purposes of selectively inhibiting the immune system, for example, to treat autoimmune disease or prevent the rejection of a grafted organ.

Centrifugal elutriation of large fragile cells: Isolation of RNA from fixed embryonic blastomeres

In order to analyze the RNA populations present in different cells of very early embryos, we have developed a protocol to purify these large blastomeres using counterflow centrifugal elutriation (CCE). This procedure employs ethanol fixation to stabilize the cells against shear forces encountered during CCE. Using this method, we fractionated the three different blastomere types of the 16-cell sea urchin embryo, the micromeres, mesomeres, and macromeres, achieving 96, 94, and 96% mean purities, respectively. We show here that intact RNA is recovered with equal efficiency from each blastomere preparation. Using this method, we have identified several RNAs that are distributed non-uniformly among these cells.

Two-photon polymerization/micromolding of microscale barbs for medical applications

Tissue barbs are small-scale structures that may be used for sutureless joining of tissues. In this study, several types of tissue barbs were fabricated using two-photon polymerization/micromolding, including two-pronged tissue barbs, eight-pronged tissue barbs, 10-pronged tissue barbs, and 16-pronged tissue barbs. Tissue barb penetration in porcine tissue was observed using confocal laser scanning microscopy. Constructs containing medical tape and tissue barbs were created by applying tissue barbs in a parallel arrangement to Transpore™ medical tape. These results suggest that two-photon polymerization/micromolding is an indirect rapid prototyping approach that may be used for high-throughput replication of tissue barbs and other microstructured solid wound sealants.