Nanomedicine in GI

Abstract

Recent advances in nanotechnology offer new hope for disease detection, prevention, and treatment. Nanomedicine is a rapidly evolving field wherein targeted therapeutic approaches using nanotechnology based on the pathophysiology of gastrointestinal diseases are being developed. Nanoparticle vectors capable of delivering drugs specifically and exclusively to regions of the gastrointestinal tract affected by disease for a prolonged period of time are likely to significantly reduce the side effects of existing otherwise effective treatments. This review aims at integrating various applications of the most recently developed nanomaterials that have tremendous potential for the detection and treatment of gastrointestinal diseases.nanoparticles; intestinal tract; diagnosis; therapeutics; nanomaterial; siRNA; gastrointestinal ALTHOUGH NANOMATERIALS (NMs) are widely considered to be an invention of modern science, they actually have a very long history. Nanoparticles (NPs) were empirically used by artisans as far back as the 9th century in Mesopotamia to generate a glittering effect on the surfaces of pots. The first scientific description of nanometer-scale metals was provided by Michael Faraday in his classic paper (25a), but the development of NMs depended mainly on their visualization and the characterization of their physical and chemical properties. Modern instrumental techniques have drastically increased our ability to precisely measure particle size distributions and many other parameters that are correlated with nanoscale objects. For example, techniques such as transmission and scanning electron microscopy and scanning tunneling microscopy have facilitated the direct visualization of individual NPs with atomic accuracy (35,46). As a result of these advances, scientists have developed exquisite and highly sophisticated methods to generate nanoscale materials with different sizes, compositions, and geometries. These nanoscale materials possess unique and unusual properties and are currently used by multidisciplinary teams of scientists in scientific areas that range from physics and engineering to biochemistry. Consequently, the field of nanomedicine has emerged alongside the development of these materials to harness some of their novel properties. Tremendous progress has been made with respect to the synthesis of a variety of materials that can be used as nanovehicles (carbons, synthetic polymers, polysaccharides, and iron, to name a few) (51, 65) and the techniques used to control the shapes and length scales of NMs. The discovery of quantum effects (size-dependent properties) that produce nanomaterials with specific emissive, absorptive, or scattering spectra has broadened the range of their potential applications in areas such as imaging and diagnostics (10,11,33). One of the most attractive applications of NM is as a drug delivery system, in which NMs are used as drug carriers. The potential to target a single cell represents a revolutionary tool for medicine. There are several advantages using NMs: NMs a...

Targeted modulation of cell differentiation in distinct regions of the gastrointestinal tract via oral administration of differently PEG-PEI functionalized mesoporous silica nanoparticles

“…8 Nanoparticulate delivery systems offer great promise and advantages in the administration of drugs also via the oral route because they are able to carry sufficient amounts of drugs that could be released at specific sites, at a specific pH value, be resistant toward digestive enzymes, and control the release of encapsulated or associated drug. 9,10 Due to these advantages, nanoparticle formulation approaches have proven to be very useful for drug delivery applications, including oral formulations. [11][12][13] Moreover, employing nanomedical concepts such as cellular targeting and intracellular drug release in oral delivery further offers the possibility of efficient and specific delivery to cells within the intestinal epithelium and thereby to specific regions of the gastrointestinal (GI) tract, offering more efficacious treatment possibilities for intestinal diseases such as colon cancer and inflammatory bowel diseases, not attainable via systemic drug delivery.…”

“…[11][12][13] Moreover, employing nanomedical concepts such as cellular targeting and intracellular drug release in oral delivery further offers the possibility of efficient and specific delivery to cells within the intestinal epithelium and thereby to specific regions of the gastrointestinal (GI) tract, offering more efficacious treatment possibilities for intestinal diseases such as colon cancer and inflammatory bowel diseases, not attainable via systemic drug delivery. 9,10 In oral formulations, amorphous silicon dioxide (SiO 2 ) or silica, has been used as a pharmaceutical excipient for .50 years and is classified by the US Food and Drug Administration as generally regarded as safe.…”

Nanotherapeutics for the treatment of inflammatory bowel disease

“…The targeting of drug delivery to the inflamed colon can be divided into three levels: targeting the colon (organ level), targeting inflamed colon sites (tissue level), and targeting specific cells (cell level) [16]. Most of the current oral formulations for IBD therapy, which include pellets, capsules, and tablets, are based on pH-, pressure-, or bacteria-responsive mechanisms [17], and can only perform organ-level targeting. NPs, in contrast, have the potential to accumulate in inflamed colon tissues passively, and studies have shown that reactive oxygen species (ROS)-sensitive formulations can induce active targeted drug delivery at the tissue level [18].…”

Synthesis of pH stable, blue light-emitting diode-excited, fluorescent silica nanoparticles and effects on cell behavior

“…34 Physiologic pH in the human body ranges from ~3 in the stomach to ~5-6 in the small intestine and 7 in the colon. 35 We therefore tested the pH stability of our NPs by adjusting the pH to 3, 5, and 7 with hydrochloric acid. The PEGylated particles did not change in size regardless of pH; however, the OH terminated did increase from 77 to 110 nm (Figure 2A).…”