Novel Poly(Ethylene Oxide)-b-Poly(Propylene Oxide) Copolymer-Glucose Conjugate by the Microwave-Assisted Ring Opening of a Sugar Lactone

Advances in active targeting of ligand-directed polymeric nanomicelles via exploiting overexpressed cellular receptors for precise nanomedicine

Many of the utilized drugs which already exist in the pharmaceutical sector are hydrophobic in nature. These drugs are characterized by being poorly absorbed and difficult to formulate in aqueous environments with low bioavailability, which could result in consuming high and frequent doses in order to fulfil the required therapeutic effect. As a result, there is a decisive demand to find modern alternatives to overcome all these drawbacks. Self-assembling polymeric nanomicelles (PMs) with their unique structure appear to be a fascinating choice as a pharmaceutical carrier system for improving the solubility & bioavailability of many drugs. PMs as drug carriers have many advantages including suitable size, high stability, prolonged circulation time, elevated cargo capacity and controlled therapeutic release. Otherwise, the pathological features of some diseased cells, like cancer, allow PMs with particle size <200 nm to be passively uptaken via enhanced permeability and retention phenomenon (EPR). However, the passive targeting approach was proven to be insufficient in many cases. Consequently, the therapeutic efficiency of these PMs can be further reinforced by enhancing their cellular internalization via incorporating targeting ligands. These targeting ligands can enhance the assemblage of loaded cargos in the intended tissues via receptor-mediated endocytosis through exploiting receptors robustly expressed on the exterior of the intended tissue while minimizing their toxic effects. In this review, the up-to-date approaches of harnessing active targeting ligands to exploit certain overexpressed receptors will be summarized concerning the functionalization of the exterior of PMs for ameliorating their targeting potential in the scope of nanomedicine.

Glucosylated Hybrid TiO2 /Polymer Nanomaterials for Actively Targeted Sonodynamic Therapy of Cancer

Sonodynamic therapy (SDT) is an anti-cancer therapeutic strategy based on the generation of reactive oxygen species (ROS) upon local ultrasound (US) irradiation of sono-responsive molecules or nanomaterials that accumulate in the tumor. In this work, the sonodynamic efficiency of sono-responsive hybrid nanomaterials composed of amorphous titanium dioxide and an amphiphilic poly(ethylene oxide)-b-poly(propylene oxide) block copolymer is synthesized, fully characterized, and investigated both in vitro and in vivo. The modular and versatile synthetic pathway enables the control of the nanoparticle size between 30 and 300 nm (dynamic light scattering) and glucosylation of the surface for active targeting of tumors overexpressing glucose transporters. Studies on 2D and 3D rhabdomyosarcoma cell cultures reveal a statistically significant increase in the sonodynamic efficiency of glucosylated hybrid nanoparticles with respect to unmodified ones. Using a xenograft rhabdomyosarcoma murine model, it is demonstrated that by tuning the nanoparticle size and surface features, the tumor accumulation is increased by ten times compared to main off-target clearance organs such as the liver. Finally, the SDT of rhabdomyosarcoma-bearing mice is investigated with 50-nm glucosylated nanoparticles. Findings evidence a dramatic prolongation of the animal survival and tumor volumes 100 times smaller than those treated only with ultrasound or nanoparticles.

Development and Evaluation of 2-Amino-7-Fluorophenazine 5,10-Dioxide Polymeric Micelles as Antitumoral Agents for 4T1 Breast Cancer

2-Amino-7-fluorophenazine 5,10-dioxide (FNZ) is a bioreducible prodrug, poorly soluble in water, with potential anticancer activity on hypoxic-tumors. This poor solubility limits its potential applications in clinic. Amphiphilic pristine polymeric micelles (PMs) based on triblock copolymers Pluronic® and Tetronic®, glycosylated derivatives and their mixtures with preformed-liposomes (LPS), were analyzed as strategies to improve the bioavailability of FNZ. FNZ encapsulations were performed and the obtaining nanostructures were characterized using UV-visible spectroscopy (UV-VIS), Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS). The most promising nanoformulations were analyzed for their potential toxicity and pharmacologically, at 20 mg/kg FNZ-doses, in a stage-IV murine metastatic-breast tumor model. The results revealed that the solubility of the encapsulated-FNZ increased up to 14 times and the analysis (UV-VIS, DLS and TEM) confirmed the interaction between vehicles and FNZ. In all the cases appropriate encapsulation efficiencies (greater than 75%), monodisperse nanometric particle sizes (PDI = 0.180-0.335), adequate Z-potentials (-1.59 to -26.4 mV), stabilities and spherical morphologies were obtained. The in vitro profile of FNZ controlled releases corresponded mainly to a kinetic Higuchi model. The in vitro/in vivo biological studies revealed non-toxicity and relevant tumor-weight diminution (up to 61%).

T908 Polymeric Micelles Improved the Uptake of Sgc8-c Aptamer Probe in Tumor-Bearing Mice: A Co-Association Study between the Probe and Preformed Nanostructures

Aptamers are oligonucleotides that have the characteristic of recognizing a target with high affinity and specificity. Based on our previous studies, the aptamer probe Sgc8-c-Alexa647 is a promising tool for molecular imaging of PTK7, which is an interesting biomarker in cancer. In order to improve the delivery of this probe as well as create a novel drug delivery nanosystem targeted to the PTK7 receptor, we evaluate the co-association between the probe and preformed nanostructures. In this work, preformed pegylated liposomes (PPL) and linear and branched pristine polymeric micelles (PMs), based on PEO–PPO–PEO triblock copolymers were used: poloxamer F127^® and poloxamines T1307^® and T908^®. For it, Sgc8-c-Alexa647 and its co-association with the different nanostructures was exhaustively analyzed. DLS analysis showed nanometric sizes, and TEM and AFM showed notable differences between free- and co-associated probe. Likewise, all nanosystems were evaluated on A20 lymphoma cell line overexpressing PTK7, and the confocal microscopy images showed distinctness in cellular uptake. Finally, the biodistribution in BALB/c mice bearing lymphoma-tumor and pharmacokinetic study revealed an encouraging profile for T908-probe. All data obtained from this work suggested that PMs and, more specifically T908 ones, are good candidates to improve the pharmacokinetics and the tumor uptake of aptamer-based probes.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2013-2014

This review is the eighth update of the original article published in 1999 on the application of Matrix-assisted laser desorption/ionization mass spectrometry (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2014. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, and arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly- saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2018 Wiley Periodicals, Inc. Mass Spec Rev 37:353-491, 2018.

Immobilization of glycans on solid surfaces for application in glycomics

Carbohydrates are an important class of biomolecules which are involved in a multitude of cellular functions. In the field of glycomics, the structure and function of various carbohydrates, oligosaccharides, glycans and their conjugates are constantly under investigation. In the continuing quest to understand the roles of carbohydrates in their interactions with proteins, immunogens, and other cell-surface carbohydrates, scientists have developed methods for observing the effects of specific saccharide sequences on various cellular components. Carbohydrate immobilization has allowed researchers to study the impact of specific sequences, leading to a deeper understanding of many cellular processes. The goal of this review is to highlight the chemical reactions and interactions that have been used for glycan immobilization.

Nanotechnology in Glycomics: Applications in Diagnostics, Therapy, Imaging, and Separation Processes

This review comprehensively covers the most recent achievements (from 2013) in the successful integration of nanomaterials in the field of glycomics. The first part of the paper addresses the beneficial properties of nanomaterials for the construction of biosensors, bioanalytical devices, and protocols for the detection of various analytes, including viruses and whole cells, together with their key characteristics. The second part of the review focuses on the application of nanomaterials integrated with glycans for various biomedical applications, that is, vaccines against viral and bacterial infections and cancer cells, as therapeutic agents, for in vivo imaging and nuclear magnetic resonance imaging, and for selective drug delivery. The final part of the review describes various ways in which glycan enrichment can be effectively done using nanomaterials, molecularly imprinted polymers with polymer thickness controlled at the nanoscale, with a subsequent analysis of glycans by mass spectrometry. A short section describing an active glycoprofiling by microengines (microrockets) is covered as well.

Challenges in oral drug delivery of antiretrovirals and the innovative strategies to overcome them

Development of novel drug delivery systems (DDS) represents a promising opportunity to overcome the various bottlenecks associated with the chronic antiretroviral (ARV) therapy of the human immunodeficiency virus (HIV) infection. Oral drug delivery is the most convenient and simplest route of drug administration that involves the swallowing of a pharmaceutical compound with the intention of releasing it into the gastrointestinal tract. In oral delivery, drugs can be formulated in such a way that they are protected from digestive enzymes, acids, etc. and released in different regions of the small intestine and/or the colon. Not surprisingly, with the exception of the subcutaneous enfuvirtide, all the marketed ARVs are administered orally. However, conventional (marketed) and innovative (under investigation) oral delivery systems must overcome numerous challenges, including the acidic gastric environment, and the poor aqueous solubility and physicochemical instability of many of the approved ARVs. In addition, the mucus barrier can prevent penetration and subsequent absorption of the released drug, a phenomenon that leads to lower oral bioavailability and therapeutic concentration in plasma. Moreover, the frequent administration of the cocktail (ARVs are administered at least once a day) favors treatment interruption. To improve the oral performance of ARVs, the design and development of more efficient oral drug delivery systems are called for. The present review highlights various innovative research strategies adopted to overcome the limitations of the present treatment regimens and to enhance the efficacy of the oral ARV therapy in HIV.

Chitosan-g-oligo(epsilon-caprolactone) polymeric micelles: microwave-assisted synthesis and physicochemical and cytocompatibility characterization

Mucoadhesive chitosan-g-oligo(epsilon-caprolactone) polymeric micelles were synthesized by a microwave-assisted technique and fully characterized in vitro.