Yongzhuo Huang

TAT-modified nanosilver for combating multidrug-resistant cancer

A nanopharmaceutical system using TAT-enhanced cell/tissue penetration strategy was developed for multidrug-resistant (MDR) cancer treatment, in which nanocrystalline silver with mean size of 8 nm modified with TAT cell-penetrating peptide (termed AgNP-TAT) displayed extraordinary antitumor activity in both MDR cells and non-resistant cells at an indiscriminating manner. Such anti-MDR effect is presumably due to the size-exclusion effect, by which the nanoparticles are too large to be pumped out. Of note, AgNP-TAT showed significant enhancement in killing tumor cells, e.g. up to 24 fold higher compared to its counterpart without TAT-modification. The animal studies further confirmed the success of our strategy that AgNP-TAT was able to effectively inhibit the tumor growth in the mice bearing malignant melanoma at a dose of 1 nmol/kg, compared with the effective dose (4.3 μmol/kg) of doxorubicin. AgNP-TAT also showed significantly reduced adverse toxicity in vivo. It indicates AgNP-TAT could be a class of nano drug for MDR cancer treatment.

Fusogenic Reactive Oxygen Species Triggered Charge‐Reversal Vector for Effective Gene Delivery

A novel fusogenic lipidic polyplex (FLPP) vector is designed to fuse with cell membranes, mimicking viropexis, and eject the polyplex into the cytosol, where the cationic polymer is subsequently oxidized by intracellular reactive oxygen species and converts to being negatively charged, efficiently releasing the DNA. The vector delivering suicide gene achieves significantly better inhibition of tumor growth than doxorubicin.

Intracellularly Acid-Switchable Multifunctional Micelles for Combinational Photo/Chemotherapy of the Drug-Resistant Tumor

The intrinsic or acquired drug resistance is the main challenge for cancer chemotherapy today. So far, many nanosized drug delivery systems (NDDS) have been exploited to combat cancer drug resistance. However, the therapy efficacy of current NDDS is severely impaired by the limited tumor penetration of the nanoparticles due to the existence of physiological and pathological barriers in the solid tumor. In this study, we report on the design and fabrication of intracellularly acid-switchable multifunctional micelles for combinational photo- and chemotherapy of the drug-resistant tumor. The micelles were composed of a pH-responsive diblock copolymer, a photosensitizer, and a polymeric prodrug of doxorubicin. The micelle displayed silenced fluorescence and photoactivity during the blood circulation and switched to an active state in weakly acid conditions (i.e., pH ≤ 6.2) in the endocytic vesicles to dramatically induce a 7.5-fold increase of the fluorescence signal for fluorescence imaging. Upon near-infrared (NIR) laser irradiation, the micelle induced notable reactive oxygen species generation to trigger cytosol release of the chemotherapeutics and perform photodynamic therapy (PDT). Moreover, the micelle efficiently converted the NIR light to local heat for enhancing tumor penetration of the anticancer drug, tumor specific photothermal therapy, and photoacoustic (PA) imaging. Furthermore, the micelles could generate amplified magnetic resonance (MR) signal in an acidic microenvironment to perform MR imaging. Collectively, this study presents a robust nanoplatform for multimodal imaging and combinational therapy of the drug-resistant tumor, which might provide an insight for developing polymer-based NDDS for cancer therapy.

Recent progress in microRNA delivery for cancer therapy by non-viral synthetic vectors☆

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression. Because of significant changes in their expression in cancer, miRNAs are believed to be key factors in cancer genetics and to have potential as anticancer drugs. However, the delivery of miRNAs is limited by many barriers, such as low cellular uptake, immunogenicity, renal clearance, degradation by nucleases, elimination by phagocytic immune cells, poor endosomal release, and untoward side effects. Nonviral delivery systems have been developed to overcome these obstacles. In this review, we provide insights into the development of non-viral synthetic miRNA vectors and the promise of miRNA-based anticancer therapies, including therapeutic applications of miRNAs, challenges of vector design to overcome the delivery obstacles, and the development of miRNA delivery systems for cancer therapy. Additionally, we highlight some representative examples that give a glimpse into the current trends into the design and application of efficient synthetic systems for miRNA delivery. Overall, a better understanding of the rational design of miRNA delivery systems will promote their translation into effective clinical treatments.

Multifunctional drug delivery system for targeting tumor and its acidic microenvironment

Effective targeting drug delivery for cancer therapy still remains a formidable challenge due to the complication and heterogeneity of malignant tumors. Herein, a multifunctional targeting strategy was proposed, in which a novel pH-sensitive polymethacrylates (PMA)-grafted poly(amidoamine) (PAMAM) nano delivery system was designed to be responsive to the acidic tumor microenvironment, and thereby trigger drug release in the intra-tumoral space. In addition, folate-PEGylation was applied to modify the surface of PMA-PAMAM nanoparticles in order to enhance tumor selectivity via both active and passive targeting mechanisms: folate receptor targeting, long circulation and EPR effect. The utility and efficacy of such system was demonstrated both in vitro and in vivo. Tumor drug accumulation was significantly enhanced by folate-PEGylated PMA-PAMAM nanoparticles, and such observation corresponded to their strong inhibition of tumor growth in tumor-bearing mice, demonstrating the success of the multifunctional targeting delivery. This multifunctional targeting strategy provides a promising solution to improve targeting drug delivery for combating the complex cancer diseases.

Inhibition of metastasis and growth of breast cancer by pH-sensitive poly (β-amino ester) nanoparticles co-delivering two siRNA and paclitaxel.

Breast cancer is the most vicious killer for womens health, while metastasis is the main culprit, which leads to failure of treatment by increasing relapse rate. In this work, a new complexes nanoparticles loading two siRNA (Snail siRNA (siSna) and Twist siRNA (siTwi)) and paclitaxel (PTX) were designed and constructed using two new amphiphilic polymer, polyethyleneimine-block-poly[(1,4-butanediol)-diacrylate-β-5-hydroxyamylamine] (PEI-PDHA) and polyethylene glycol-block-poly[(1,4-butanediol)-diacrylate-β-5-hydroxyamylamine] (PEG-PDHA) by self-assembly. The experimental results showed that in the 4T1 tumor-bearing mice models, PEI-PDHA/PEG-PDHA/PTX/siSna/siTwi) complex nanoparticles (PPSTs) raised the accumulation and retention of both PTX and siRNA in tumor after administrated intravenously, resulted in the strong inhibition of the tumor growth and metastasis simultaneously. It was found that co-delivery of siSna and siTwi had more significant anti-metastasis effect than delivering a single siRNA, as a result of simultaneously inhibiting the motility of cancer cells and degradation of ECM. Therefore, PPSTs could be a promising co-delivery vector for effective therapy of metastatic breast cancer.

Magnetic Nanoparticles for Tumor Imaging and Therapy: A So-Called Theranostic System

ABSTRACTIn this review, we discussed the establishment of a so-called “theranostic” system by instituting the basic principles including the use of: [1] magnetic iron oxide nanoparticles (MION)-based drug carrier; [2] intra-arterial (I.A.) magnetic targeting; [3] macromolecular drugs with unmatched therapeutic potency and a repetitive reaction mechanism; [4] cell-penetrating peptide-mediated cellular drug uptake; and [5] heparin/protamine-regulated prodrug protection and tumor-specific drug re-activation into one single drug delivery system to overcome all possible obstacles, thereby achieving a potentially non-invasive, magnetic resonance imaging-guided, clinically enabled yet minimally toxic brain tumor drug therapy. By applying a topography-optimized I.A. magnetic targeting to dodge rapid organ clearance of the carrier during its first passage into the circulation, tumor capture of MION was enriched by >350 folds over that by conventional passive enhanced permeability and retention targeting. By adopting the prodrug strategy, we observed by far the first experimental success in a rat model of delivering micro-gram quantity of the large β-galactosidase model protein selectively into a brain tumor but not to the ipsi- or contra-lateral normal brain regions. With the therapeutic regimens of most toxin/siRNA drugs to fully (>99.9%) eradicate a tumor being in the nano-molar range, the prospects of reaching this threshold become practically accomplishable.

Codelivery of Sorafenib and Curcumin by Directed Self-Assembled Nanoparticles Enhances Therapeutic Effect on Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related mortality worldwide. Herein, we first reported the codelivery of sorafenib and curcumin by directed self-assembled nanoparticles (SCN) to enhance the therapeutic effect on HCC. SCN was formed by employing the hydrophobic interactions among the lipophilic structure in sorafenib, curcumin, and similar hydrophobic segments of polyethylene glycol derivative of vitamin E succinate (PEG-VES), which comprised uniform spherical particles with particle size of 84.97 ± 6.03 nm. SCN presented superior effects over sorafenib, curcumin, and their physical mixture (Sora + Cur) on enhancing in vitro cytotoxicity and cell apoptosis in BEL-7402 cells and Hep G2 cells, and antiangiogenesis activities in tube formation and microvessel formation from aortic rings. Moreover, the tissue concentration of sorafenib and curcumin in gastrointestinal tract and major organs were significantly improved after their coassembly into SCN. In particular, in BEL-7402 cells induced tumor xenograft, SCN treatment displayed the obviously enhanced inhibitory effect on tumor progression over free drug monotherapy or their physical mixture, with significantly increased antiproliferation and antiangiogenesis capability. Thereby, the codelivered nanoassemblies of sorafenib and curcumin provided a promising strategy to enhance the combinational therapy of HCC.

The use of low molecular weight protamine chemical chimera to enhance monomeric insulin intestinal absorption.

Although oral delivery of insulin offers a number of unmatched advantages, it nevertheless is beset by the poor permeability of insulin molecules through the epithelial cell membranes of the intestinal mucosal layer. We previously reported the development of low molecular weight protamine (LMWP) as a non-toxic yet potent cell-penetrating peptide, of which via covalent linkage was capable of translocating protein cargos through the membranes of almost all cell types. It is therefore hypothesized that LMWP could be practically employed as a safe and effective tool to deliver insulin across the intestinal mucosal membrane, thereby augmenting its absorption through the GI tract. However, formulating 1:1 monomeric insulin/LMWP conjugate presents a tall order of challenge, as the acidic insulin and basic LMWP would automatically form tight aggregates through electrostatic interactions. In this paper, we developed an innovative conjugation strategy to solve this problem, by using succinimidyl-[(N-maleimidopropionamido)-polyethyleneglycol] ester (NHS-PEG-MAL) as an intermediate cross-linker during the coupling process. Both SDS-PAGE and MALDI-TOF mass spectroscopy confirmed the formation of a homogenous, monomeric (1:1 ratio) insulin/LMWP conjugate without encountering the conventional problem of substrate aggregation. Cell culture studies demonstrated that transport of the Insulin-PEG-LMWP conjugate across the intestinal mucosal monolayer was augmented by almost five-folds compared to native insulin. Furthermore, results from the in situ loop absorption tests in rats showed that systemic pharmacological bioavailability of insulin was significantly enhanced after its conjugation with LMWP. Overall, the presented chemical conjugation with LMWP could offer a reliable and safe means to improve the intestinal permeability of therapeutic peptides/proteins, shedding light of the possibility for their effective oral delivery.

In vivo delivery of cell-permeable antisense hypoxia-inducible factor 1α oligonucleotide to adipose tissue reduces adiposity in obese mice

Ongoing research has gradually recognized and understood the importance of adipose tissue (AT) angiogenesis as a key modulating factor of adipogenesis in the development of obesity. Previously, we carried out the first in vitro demonstration of the down-regulation of hypoxic angiogenesis during adipogenesis using cell-permeable chemical conjugates composed of antisense hypoxia-inducible factor 1α (HIF1α) oligonucleotide (ASO) and low-molecular weight protamine (LMWP). To further confirm the in vivo feasibility, we administered ASO-LMWP conjugates (AL) to diet-induced obese (DIO) mice by intraperitoneal injection (IP). Results showed that the AL conjugates significantly reduced the body weight, total fat tissue weight, and plasma lipid concentrations in the mice. Moreover, the AL conjugates not only decreased liver weight and hepatic triglyceride concentration but also significantly attenuated subcutaneous adipocyte cell size, which was conversely increased in the AL-untreated high-fat diet (HFD) group. Interestingly, more blood vessels were observed in the HFD group than in the lean group, indicating that blood vessel development could induce growth of the fat mass. This pattern was reversed in the AL-treated groups, which displayed a decrease in blood vessel density compared to the AL-untreated HFD group. This study presents the first in vivo evidence, in an obese mouse model, of the feasibility of achieving a biological treatment modality for obesity by blocking the angiogenic transcriptional factor HIF1α, thereby limiting angiogenesis, via the use of an adipose tissue-permeable ASO-LMWP.