Development of exosome-encapsulated paclitaxel to overcome MDR in cancer cells

AbstractExosomes have recently come into focus as "natural nanoparticles" for use as drug delivery vehicles. Our objective was to assess the feasibility of an exosome-based drug delivery platform for a potent chemotherapeutic agent, paclitaxel (PTX), to treat MDR cancer. Herein, we developed different methods of loading exosomes released by macrophages with PTX (exoPTX), and characterized their size, stability, drug release, and in vitro antitumor efficacy. Reformation of the exosomal membrane upon sonication resulted in high loading efficiency and sustained drug release. Importantly, incorporation of PTX into exosomes increased cytotoxicity more than 50 times in drug resistant MDCKMDR1 (Pgp+) cells. Next, our studies demonstrated a nearly complete co-localization of airway-delivered exosomes with cancer cells in a model of murine Lewis lung carcinoma pulmonary metastases, and a potent anticancer effect in this mouse model. We conclude that exoPTX holds significant potential for the delivery of various chemotherapeutics to treat drug resistant cancers.From the Clinical EditorExosomes are membrane-derived natural vesicles of ~40 - 200 nm size. They have been under extensive research as novel drug delivery vehicles. In this article, the authors developed exosome-based system to carry formulation of PTX and showed efficacy in the treatment of multi-drug resistant cancer cells. This novel system may be further developed to carry other chemotherapeutic agents in the future

Towards nanomedicines of the future: Remote magneto-mechanical actuation of nanomedicines by alternating magnetic fields

The paper describes the concept of magneto-mechanical actuation of single-domain magnetic nanoparticles (MNPs) in super-low and low frequency alternating magnetic fields (AMFs) and its possible use for remote control of nanomedicines and drug delivery systems. The applications of this approach for remote actuation of drug release as well as effects on biomacromolecules, biomembranes, subcellular structures and cells are discussed in comparison to conventional strategies employing magnetic hyperthermia in a radio frequency (RF) AMF. Several quantitative models describing interaction of functionalized MNPs with single macromolecules, lipid membranes, and proteins (e.g. cell membrane receptors, ion channels) are presented. The optimal characteristics of the MNPs and an AMF for effective magneto-mechanical actuation of single molecule responses in biological and bio-inspired systems are discussed. Altogether, the described studies and phenomena offer opportunities for the development of novel therapeutics both alone and in combination with magnetic hyperthermia

Superoxide Dismutase 1 Nanozyme for Treatment of Eye Inflammation

Use of antioxidants to mitigate oxidative stress during ocular inflammatory diseases has shown therapeutic potential. This work examines a nanoscale therapeutic modality for the eye on the base of antioxidant enzyme, superoxide dismutase 1 (SOD1), termed “nanozyme.” The nanozyme is produced by electrostatic coupling of the SOD1 with a cationic block copolymer, poly(L-lysine)-poly(ethyleneglycol), followed by covalent cross-linking of the complexes with 3,3′-dithiobis(sulfosuccinimidylpropionate) sodium salt. The ability of SOD1 nanozyme as well as the native SOD1 to reduce inflammatory processes in the eye was examined in vivo in rabbits with immunogenic uveitis. Results suggested that topical instillations of both enzyme forms demonstrated anti-inflammatory activity; however, the nanozyme was much more effective compared to the free enzyme in decreasing uveitis manifestations. In particular, we noted statistically significant differences in such inflammatory signs in the eye as the intensities of corneal and iris edema, hyperemia of conjunctiva, lens opacity, fibrin clots, and the protein content in aqueous humor. Clinical findings were confirmed by histological data. Thus, SOD1-containing nanozyme is potentially useful therapeutic agent for the treatment of ocular inflammatory disorders

Macrophages offer a paradigm switch for CNS delivery of therapeutic proteins

Active targeted transport of the nanoformulated redox enzyme, catalase, in macrophages attenuates oxidative stress and as such increases survival of dopaminergic neurons in animal models of Parkinson’s disease. Optimization of the drug formulation is crucial for the successful delivery in living cells. We demonstrated earlier that packaging of catalase into a polyion complex micelle (‘nanozyme’) with a synthetic polyelectrolyte block copolymer protected the enzyme against degradation in macrophages and improved therapeutic outcomes. We now report the manufacture of nanozymes with superior structure and therapeutic indices

Extracellular Vesicle-Based Therapeutics: Preclinical and Clinical Investigations

Drug nanoformulations hold remarkable promise for the efficient delivery of therapeutics to a disease site. Unfortunately, artificial nanocarriers, mostly liposomes and polymeric nanoparticles, show limited applications due to the unfavorable pharmacokinetics and rapid clearance from the blood circulation by the reticuloendothelial system (RES). Besides, many of them have high cytotoxicity, low biodegradability, and the inability to cross biological barriers, including the blood brain barrier. Extracellular vesicles (EVs) are novel candidates for drug delivery systems with high bioavailability, exceptional biocompatibility, and low immunogenicity. They provide a means for intercellular communication and the transmission of bioactive compounds to targeted tissues, cells, and organs. These features have made them increasingly attractive as a therapeutic platform in recent years. However, there are many obstacles to designing EV-based therapeutics. In this review, we will outline the main hurdles and limitations for therapeutic and clinical applications of drug loaded EV formulations and describe various attempts to solve these problems

Up- and Down-Regulation of Enzyme Activity in Aggregates with Gold-Covered Magnetic Nanoparticles Triggered by Low-Frequency Magnetic Field

The modern global trend toward sustainable processes that meet the requirements of “green chemistry” provides new opportunities for the broad application of highly active, selective, and specific enzymatic reactions. However, the effective application of enzymes in industrial processes requires the development of systems for the remote regulation of their activity triggered by external physical stimuli, one of which is a low-frequency magnetic field (LFMF). Magnetic nanoparticles (MNPs) transform the energy of an LFMF into mechanical forces and deformations applied to enzyme molecules on the surfaces of MNPs. Here, we demonstrate the up- and down-regulation of two biotechnologically important enzymes, yeast alcohol dehydrogenase (YADH) and soybean formate dehydrogenase (FDH), in aggregates with gold-covered magnetic nanoparticles (GCMNPs) triggered by an LFMF. Two types of aggregates, “dimeric” (with the enzyme attached to several GCMNPs simultaneously), with YADH or FDH, and “monomeric” (the enzyme attached to only one GCMNP), with FDH, were synthesized. Depending on the aggregate type (“dimeric” or “monomeric”), LFMF treatment led to a decrease (down-regulation) or an increase (up-regulation) in enzyme activity. For “dimeric” aggregates, we observed 67 ± 9% and 47 ± 7% decreases in enzyme activity under LFMF exposure for YADH and FDH, respectively. Moreover, in the case of YADH, varying the enzyme or the cross-linking agent concentration led to different magnitudes of the LFMF effect, which was more significant at lower enzyme and higher cross-linking agent concentrations. Different responses to LFMF exposure depending on cofactor presence were also demonstrated. This effect might result from a varying cofactor binding efficiency to enzymes. For the “monomeric” aggregates with FDH, the LFMF treatment caused a significant increase in enzyme activity; the magnitude of this effect depended on the cofactor type: we observed up to 40% enzyme up-regulation in the case of NADP+, while almost no effect was observed in the case of NAD+

pH-Dependent Substrate Preference of Pig Heart Lipoamide Dehydrogenase Varies with Oligomeric State: Response to Mitochondrial Matrix Acidification

Cycling of intracellular pH has recently been shown to play a critical role in ischemia-reperfusion injury. Ischemia-reperfusion also leads to mitochondrial matrix acidification and dysfunction. However, the mechanism by which matrix acidification contributes to mitochondrial dysfunction, oxidative stress, and the resultant cellular injury has not been elucidated. We observe pH-dependent equilibria between monomeric, dimeric, and a previously undescribed tetrameric form of pig heart lipoamide dehydrogenase (LADH), a mitochondrial matrix enzyme. Dynamic light scattering studies of native LADH in aqueous solution indicate that lowering pH favors a shift in average molecular mass from higher oligomeric states to monomer. Sedimentation velocity of LADH entrapped in reverse micelles reveals dimer and tetramer at both pH 5.8 and 7.5, but monomer was observed only at pH 5.8. Enzyme activity measurements in reverse Aerosol OT micelles in octane indicate that LADH dimer and tetramer possess lipoamide dehydrogenase and diaphorase activities at pH 7.5. Upon acidification to pH 5.8 only the LADH monomer is active and only the diaphorase activity is ob¬served. These results indicate a correlation between pH-dependent changes in the LADH reaction specificity and its oligomeric state. The acidification of mitochondrial matrix that occurs during ischemia-reperfusion injury is sufficient to alter the structure and enzymatic specificity of LADH, thereby reducing mitochondrial defenses, increasing oxidative stress, and slowing the recovery of energy metabolism. Matrix acidification may also disrupt the quaternary structure of other mitochondrial protein complexes critical for cellular homeostasis and survival

Protein extracting electrodes: insights in the mechanism

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Recent Advances in Nanopore Technology for Copper Detection and Their Potential Applications

Recently, nanopore technology has emerged as a promising technique for the rapid, sensitive, and selective detection of various analytes. In particular, the use of nanopores for the detection of copper ions has attracted considerable attention due to their high sensitivity and selectivity. This review discusses the principles of nanopore technology and its advantages over conventional techniques for copper detection. It covers the different types of nanopores used for copper detection, including biological and synthetic nanopores, and the various mechanisms used to detect copper ions. Furthermore, this review provides an overview of the recent advancements in nanopore technology for copper detection, including the development of new nanopore materials, improvements in signal amplification, and the integration of nanopore technology with other analytical methods for enhanced detection sensitivity and accuracy. Finally, we summarize the extensive applications, current challenges, and future perspectives of using nanopore technology for copper detection, highlighting the need for further research in the field to optimize the performance and applicability of the technique