Dextran sulfate-based MMP-2 enzyme-sensitive SR-A receptor targeting nanomicelles for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is an ordinarily occurring autoimmune disease with systemic inflammatory. Targeted drug delivery systems have many successful applications in the treatment of rheumatoid arthritis. In order to develop nanoparticles for targeted delivery of Celastrol (Cel) to rheumatoid arthritis and specific drug release, the dextran sulfate (DS) was modified as the targeting molecular by binding to the scavenger receptor of macrophage. The dextran-sulfate-PVGLIG-celastrol (DS-PVGLIG-Cel), named DPC, amphiphilic polymeric prodrug was synthesized and characterized. The resulting DPC@Cel micelles had the average size of 189.9 nm. Moreover, the micelles had ultrahigh entrapment efficiency (about 44.04%) and zeta potential of −11.91 mV. In the in vitro release study, due to the excessive production of matrix metalloproteinase-2 (MMP-2) at the inflammatory joint, the MMP-2 reactive peptide was used to crack in the inflammatory microenvironment to accelerate the release of Cel. The results have shown that the nanoparticles can effectively deliver Cel to activated macrophages and significantly improve the bioavailability. In vivo experiments showed that DPC@Cel have better anti-rheumatoid arthritis effects and lower systemic toxicity than free Cel. This study provided a new therapeutic strategy for the treatment of RA.

Ligand-Modified Erythrocyte Membrane-Cloaked Metal-Organic Framework Nanoparticles for Targeted Antitumor Therapy

Systemic chemotherapy for treating tumors often leads to serious systemic side effects and affects patient compliance. Although the emerging technology of drug delivery systems (DDSs) can deliver the required cargo to tumor sites, DDSs are limited due to insufficient targeting ability or deficient pharmacokinetics. Herein, we assembled a novel targeting DDS for precision tumor therapy by applying a tumor-targeting polypeptide cyclic RGD (cRGD)-modified erythrocyte membrane (eM-cRGD) cloaked on zeolitic imidazolate framework-8 (ZIF-8) nanoparticles (NPs) with encapsulated doxorubicin (DOX). For a mass ratio of ZIF-8:DOX = 1:1, the loading capacity was up to 49%. The nanoscale-sized targeting DDS promoted NP accumulation in tumor tissues via enhanced permeability and retention (EPR) effects, and the NPs actively targeted ligands and were then transferred to endosomes. The pH-sensitive carriers released higher DOX levels under the low pH mimicking that of a tumor microenvironment and tumor intracellular organelles, allowing enhanced inhibition of cancer cell growth. The cumulative release rate of DOX from DOX@ZIF-8 NPs reached 82.8% at 48 h in acidic conditions of pH = 5.0, while the cumulative release rate of DOX from the DOX@ZIF-8 NPs reached only 24.92% at pH = 7.4. The internalization of the DDS was approximately 44.35% that of the unmodified DDS by immune cells, as confirmed by flow cytometry. In vivo studies verified that the RGD-modified DDS had the ability to prolong blood circulation (t_1/2 = 6.81 h), enhancing the tumor-specific accumulation of NPs by means of the integrin αvβ3 receptor-mediated pathway, which was further valuated in mice bearing human cervical cancer (HeLa) cells, and yielding a significant antitumor effect; the tumor inhibition rate was as high as 85.46%. Under the same conditions, the blood circulation half-life of the unmodified DDS was only 3.22 h, and the tumor inhibition rate of free DOX was 81.34%. Moreover, the RGD modified with a carrier could achieve a satisfactory chemotherapeutic effect while minimizing side effects. In summary, our novel targeting DDS could contribute to the development of intelligent DDSs for tumor precision therapy.

Metal Organic Frameworks as Drug Targeting Delivery Vehicles in the Treatment of Cancer

: In recent years, metal organic frameworks (MOFs) have been widely developed as vehicles for the effective delivery of drugs to tumor tissues. Due to the high loading capacity and excellent biocompatibility of MOFs, they provide an unprecedented opportunity for the treatment of cancer. However, drugs which are commonly used to treat cancer often cause side effects in normal tissue accumulation. Therefore, the strategy of drug targeting delivery based on MOFs has excellent research significance. Here, we introduce several intelligent targeted drug delivery systems based on MOFs and their characteristics as drug-loading systems, and the challenges of MOFs are discussed. This article covers the following types of MOFs: Isoreticular Metal Organic Frameworks (IRMOFs), Materials of Institute Lavoisier (MILs), Zeolitic Imidazolate Frameworks (ZIFs), University of Oslo (UiOs), and MOFs-based core-shell structures. Generally, MOFs can be reasonably controlled at the nanometer size to effectively achieve passive targeting. In addition, different ligands can be modified on MOFs for active or physicochemical targeting. On the one hand, the targeting strategy can improve the concentration of the drugs at the tumor site to improve the efficacy, on the other hand, it can avoid the release of the drugs in normal tissues to improve safety. Despite the challenges of clinical application of MOFs, MOFs have a number of advantages as a kind of smart delivery vehicle, which offer possibilities for clinical applications.

Recent advance of nanoparticle-based topical drug delivery to the posterior segment of the eye

INTRODUCTION

Considering that the number of patients afflicted by posterior eye diseases is increasing, effective drug delivery is currently in high clinical demand. Topical administration has been identified as the preferred option, while sufferingfrom multiple barriers. The development of nanoparticle-based drug delivery system provides an option, which would enhance the drug permeability across the barriers and achieve the desired drug level in the targeted tissue.

AREAS COVERED

This review highlights the barrier to the posterior segment of the eye via topical administration. The up-to-date development of lipid nanoparticles, liposomes, emulsions, spanlastics, micelles, polymeric nanoparticles, layered double hydroxides (LDH), dendrimers, cyclodextrins(CDs), and prodrugs are summarized. Moreover, nanocarriers currently in clinical trials for posterior segment diseases have been discussed.

EXPERT OPINION

Topical nanoparticle-based drug delivery systems have demonstrated significant progress. An ideal formulation should prolong retention time on the surface, enhance drug permeability through the ocular tissues, and efficiently deliver drugs to the targeted site. To design the rational targeting nanoparticle-based drug delivery system, a better understanding of the distribution of transporters and receptors on the eye is required. Ultimately, there is an urgent need to develop targeting hybrid drug delivery systems with the combination of the advantages of several nanocarriers.

Targeting High Expressed α5β1 Integrin in Liver Metastatic Lesions To Resist Metastasis of Colorectal Cancer by RPM Peptide-Modified Chitosan-Stearic Micelles

Liver metastasis is a leading death cause in colorectal cancer. The pathological differences between orthotopic tumors and metastatic lesions increased the therapeutic difficulty of metastasis. Herein, the α₅β₁ integrin receptor expression on metastatic cells was first measured, the result showed that metastatic cells expressed the α₅β₁ integrin higher than that of the original cells from orthotopic tumors. Afterward, RPM peptide-modified chitosan-stearic (RPM-CSOSA) was designed based on α₅β₁ integrin expression. The cytotoxicity and resistance to migration and the invasion ability of the targeting drug delivery system loading doxorubicin (DOX) and curcumin (CUR) were evaluated in vitro. The metastatic inhibition of the targeting drug delivery system was also investigated in HT29 liver metastatic models. The modified RPM peptide could increase the cellular internalization of CSOSA micelles in metastatic tumor cells and endothelial cells mediated by α₅β₁ integrin. The synergistic effects of RPM-CSOSA/DOX and RPM-CSOSA/CUR could obviously inhibit migratory and invasive abilities of HT29 cells and endothelial cells. Moreover, the RPM-CSOSA/DOX&RPM-CSOSA/CUR could obviously decrease the number of metastatic sites by 86.96%, while CSOSA/DOX&CSOSA/CUR decreased liver metastasis by 66.58% compared with that in the saline group. In conclusion, the RPM peptide-modified drug delivery system may provide insights into targeting the metastatic cells overexpressing the α₅β₁ integrin, and it has the potential to inhibit liver metastasis of colorectal cancer.

Dual-Targeting Multifuntional Mesoporous Silica Nanocarrier for Codelivery of siRNA and Ursolic Acid to Folate Receptor Overexpressing Cancer Cells

A targeting drug delivery system (TDDS) can selectively deliver antitumor drugs to cancerous parts to improve its anticancer efficacy. Hence, a targeted drug delivery system (UA/siVEGF@MSN-FA) coloading ursolic acid (UA) and vascular endothelial growth factor (VEGF) targeted siRNA (siVEGF) based on mesoporous silica (MSN) nanocarrier modified by a folic acid (FA) molecule was designed and synthesized. The MSN-FA nanoparticles were investigated for shape, diameter, and zeta potential and and by infrared (IR) spectroscopy. FR-overexpressing HeLa cells and FR-negative HepG2 cell lines were used to evaluate the in vitro cellular uptake and the cytotoxicity of MSN-FA nanoparticles. The morphology of HeLa cells transfected with siVEGF@MSN-FA was observed using fluorescence microscopy. Our findings demonstrated that UA@MSN-FA nanoparticles were near-spherical, and the particle size was about 209 ± 9.21 nm. The MSN-FA nanocarrier not only could enhance the in vitro transfection efficiency and the stability of siVEGF but also could further improve the targeted anticancer efficacy of UA and siVEGF via the active targeting property of FA. Overall, the MSN-FA drug delivery system could serve as an excellent material in biomedical applications.

Hyaluronic acid and Arg-Gly-Asp peptide modified Graphene oxide with dual receptor-targeting function for cancer therapy

Graphene oxide (GO) modified with hyaluronic acid (HA) and Arg-gly-asp peptide (RGD) was designed as a dual-receptor targeting drug delivery system to enhance the specificity and efficiency of anticancer drug delivery. Firstly, GO-HA-RGD conjugate was characterized to reveal its structure and morphology. Whereafter, doxorubicin (Dox) as a model drug was loaded on GO-HA-RGD carrier, which displayed a high loading rate (72.9%, GO:Dox (w/w) = 1:1), pH-response and sustained drug release behavior. Cytotoxicity experiments showed that GO-HA-RGD possessed excellent biocompatibility towards SKOV-3 and HOSEpiC cells. Additionally, the GO-HA-RGD/Dox had a stronger cytotoxicity for SKOV-3 cells than either GO-HA/Dox (single receptor) or GO/Dox (no receptor). Moreover, celluar uptake studies illustrated that GO-HA-RGD conjugate could be effectively taken up by SKOV-3 cells via a synergic effect of CD44-HA and integrin-RGD mediated endocytosis. Hence, GO-HA-RGD nanocarrier is able to be a promising platform for targeted cancer therapeutic.

A promising strategy for overcoming MDR in tumor by magnetic iron oxide nanoparticles co-loaded with daunorubicin and 5-bromotetrandrin

To overcome both the dose-limiting side effects of conventional chemotherapeutic agents and the therapeutic failure resulting from multidrug resistance (MDR) and minimize adverse effects of chemotherapy agents, a novel chemotherapy formulation of magnetic nanoparticles co-loaded with daunorubicin and 5-bromotetrandrin (DNR/BrTet-MNPs) was developed, and its effect on MDR leukemic cells was explored. After the DNR and Br were co-loaded onto a pluronic-stabilized and oleic acid-modified magnetic nanosystem, the physical characteristic and drug-loading capacity were evaluated. The cell toxicity of the self-prepared DNR/BrTet-MNPs formulation was then determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay; the cellular uptake of drug was demonstrated by fluorescent microscope. Lastly, the transcription of mdr1 and the expression of P-glycoprotein (P-gp) were detected by the reverse transcription reaction and western blotting assay, respectively. The results showed that the self-prepared DNR/BrTet-MNPs formulation possessed a sustained release of drug and displayed a dose-dependent antiproliferative activity on MDR leukemia K562/A02 cells. It also enhanced the accumulation of intracellular DNR in K562/A02 cells and downregulated the transcription of the mdr1 gene and the expression of P-gp. These findings suggest that the remarkable effect of the novel DNR/BrTet-MNPs formulation, acting as a drug depot system for the sustained release of the loaded DNR and BrTet, on multidrug resistance leukemia K562/A02 cells would be a promising strategy for overcoming MDR.