Linan Zhang

Nanotechnology applied to overcome tumor drug resistance

Emerging multidrug resistance (MDR) to chemotherapy is a major obstacle in successfully treating malignant diseases. Nanotechnology provides an innovative and promising alternative strategy compared to conventional small molecule chemotherapeutics to circumvent MDR. This review focuses on recent literature examples of nanotechnology applications to overcome MDR. The advantages and limitations of various nanotechnologies are discussed as well as possible approaches to overcome the limitations. Developing a practical nanotechnology-based drug delivery system requires further studies of the tumor microenvironment, the mechanisms of MDR to chemotherapy, the optimal dosage regimen of anticancer drugs and/or siRNA, the transport kinetics of nanocarriers in tumor stroma and the pharmacokinetics of drug-loaded nanocarriers within MDR tumor cells.

Mesenchymal stem cells: a potential targeted-delivery vehicle for anti-cancer drug loaded nanoparticles

UNLABELLED The targeted delivery of anticancer agents is a promising field in anticancer therapy. Mesenchymal stem cells (MSCs) have inherent tumor-tropic and migratory properties, which allow them to serve as vehicles for targeted drug delivery systems for isolated tumors and metastatic diseases. MSCs have been successfully studied and discussed as a vehicle for cancer gene therapy. However, MSCs have not yet been discussed adequately as a potential vehicle for traditional anticancer drugs. In this review, we will examine the potential of MSCs as a targeted-delivery vehicle for anticancer drug-loaded nanoparticles (NPs), summarize various challenges, and discuss possible solutions for these challenges. FROM THE CLINICAL EDITOR In this review, the feasibility of mesenchymal stem cell-based targeted delivery of anticancer agents is discussed.

Na+-K+-ATPase, a potent neuroprotective modulator against Alzheimer disease

Alzheimer disease (AD) is a neurodegenerative disorder clinically characterized by progressive cognitive and memory dysfunction, which is the most common form of dementia. Although the pathogenesis of neuronal injury in AD is not clear, recent evidences suggest that Na+‐K+‐ATPase plays an important role in AD, and may be a potent neuroprotective modulator against AD. This review aims to provide readers with an in‐depth understanding of Na+‐K+‐ATPase in AD through these modulations of some factors that are as follows, which leads to the change of learning and memory in the process of AD.

Study of amphotericin B magnetic liposomes for brain targeting

This study aims to prepare amphotericin B magnetic liposomes (AmB-MLPs), which may improve drug concentration in brain, enhance magnetic targeting for brain and reduce drug toxicity in the presence of magnetic field. AmB-MLPs were prepared by means of film dispersion-ultrasonication, and their physical properties were characterized. In vivo, the magnetic targeting for brain by carotid artery administration was investigated. The particle size of AmB-MLPs was 240±11 nm, the encapsulation efficiency was 79.32±2.03%, and the saturation magnetization was 32.54 memu g⁻¹ at room temperature, which had good magnetic responsiveness. The group of AmB injection was delivered by carotid artery, nevertheless they all died after 20 min. AmB-MLPs were injected by carotid artery, and the drug concentration in brain tissue was obviously increased in presence of magnetic field than that of in absence of magnetic field (P<0.05). The Prussian blue staining in brain of SD rats showed that the density of blue staining-positive particles in brain tissue of applying magnetic field group was higher than that of non magnetic field group. These results suggested that AmB-MLPs could reinforce brain targeting and reduce drug toxicity when they were injected by carotid artery under the effect of magnetic field.

Preparation and drug release mechanism of CTS-TAX-NP-MSCs drug delivery system

Targeting delivery of anticancer agents is a promising field in anticancer therapy. Inherent tumor-tropic and migratory properties of mesenchymal stem cells (MSCs) make them potential vehicles for targeting drug delivery systems for tumors. Although, MSCs have been successfully studied and discussed as a vehicle for cancer gene therapy, they have not yet been studied adequately as a potential vehicle for traditional chemical anticancer drugs. In this study, we have engineered MSCs as a potential targeting delivery vehicle for paclitaxel (TAX)-loaded nanoparticles (NPs). The size, surface charge, starving time of MSCs, incubating time and concentration of NPs could influence the efficiency of NPs uptake. In vitro release of TAX from CTS (chitosan)-TAX-NP-MSCs and the expression of P-glycoprotein demonstrated that release of TAX from MSCs might involve both passive diffusion and active transport. In vitro migration assays indicated that MSCs at passage number 3 have the highest migrating ability. Although, the migration ability of CTS-TAX-NP-MSCs could be inhibited by uptake of CTS-TAX-NPs, this ability could recover 6 days after the internalization.

Glutamate Transporters/Na+, K+-ATPase Involving in the Neuroprotective Effect as a Potential Regulatory Target of Glutamate Uptake

The glutamate (Glu) transporters GLAST and GLT-1, as the two most important transporters in brain tissue, transport Glu from the extracellular space into the cell protecting against Glu toxicity. Furthermore, GLAST and GLT-1 are sodium-dependent Glu transporters (GluTs) that rely on sodium and potassium gradients generated principally by Na+, K+-ATPase to generate ion gradients that drive Glu uptake. There is an interaction between Na+, K+-ATPase and GluTs to modulate Glu uptake, and Na+, K+-ATPase α, β or γ subunit can be directly coupled to GluTs, co-localizing with GLAST or GLT-1 in vivo to form a macromolecular complex and operate as a functional unit to regulate glutamatergic neurotransmission. Therefore, GluTs/Na+, K+-ATPase may be involved in the neuroprotective effect as a potential regulatory target of Glu uptake in neurodegenerative diseases induced by Glu-mediated neurotoxicity as the final common pathway.

In-vitro and in-vivo evaluation of austocystin D liposomes.

The purpose this study is to enhance the anti‐tumour activity of austocystin D (AD) by AD‐loaded liposomes (AD‐Ls).