A Multifunctional Hybrid Nanocarrier for Non-Invasive siRNA Delivery to the Retina.

Drug therapy for retinal diseases (e.g., age-related macular degeneration, the leading cause of blindness) is generally performed by invasive intravitreal injection because of poor drug delivery caused by the blood-retinal barrier (BRB). This study aimed to develop a nanocarrier for the non-invasive delivery of small interfering RNA (siRNA) to the posterior segment of the eye (i.e., the retina) by eyedrops. To this end, we prepared a hybrid nanocarrier based on a multifunctional peptide and liposomes, and the composition was optimized. A cytoplasm-responsive stearylated peptide (STR-CH2R4H2C) was used as the multifunctional peptide because of its superior ability to enhance the complexation, cell permeation, and intracellular dynamics of siRNA. By adding STR-CH2R4H2C to the surface of liposomes, intracellular uptake increased regardless of the liposome surface charge. The STR-CH2R4H2C-modified cationic nanocarrier demonstrated significant siRNA transfection efficiency with no cytotoxicity, enhanced siRNA release from endosomes, and effectively suppressed vascular endothelial growth factor expression in rat retinal pigment epithelium cells. The 2.0 mol% STR-CH2R4H2C-modified cationic nanocarrier enhanced intraocular migration into the retina after instillation into rat eyes.

Systemic delivery of siRNA to the colon using peptide modified PEG-PCL polymer micelles for the treatment of ulcerative colitis.

Ulcerative colitis (UC) is a refractory inflammatory bowel disease that causes inflammation and ulcers in the digestive tract, and significantly reduces the patient's quality of life. While existing UC treatments have many challenges, nanotechnology, and small interfering RNA (siRNA) based formulations are novel and promising for UC treatment. We previously reported that intravenous administration of MPEG-PCL-CH2R4H2C nanomicelles had high inflammatory site accumulation and remarkable therapeutic effects on rheumatoid arthritis by a phenomenon similar to enhanced permeability and retention effect. In this study, we investigated the effects of siRNA delivered using MPEG-PCL-CH2R4H2C nanomicelles through intravenous administration to the inflammation site of dextran sulfate sodium-induced colitis mice. The MPEG-PCL-CH2R4H2C micelles had optimum physical properties and high siRNA compaction ability. Moreover, model-siRNA delivered through MPEG-PCL-CH2R4H2C showed higher accumulation in the inflammatory site than that of the naked siRNA. Furthermore, intravenous administration of MPEG-PCL-CH2R4H2C/siRelA micelles, targeting siRelA, a subunit of NF-κB, significantly decreased the shortening of large intestine, clinical score, and production of inflammatory cytokines compared the 5-ASA and naked siRelA. These results suggest that MPEG-PCL-CH2R4H2C is a useful carrier for the systemic delivery and accumulation of siRNA, thus improving its therapeutic effect.

In Vivo Fluorescence Imaging of Passive Inflammation Site Accumulation of Liposomes via Intravenous Administration Focused on Their Surface Charge and PEG Modification.

Nanocarriers such as liposomes have been attracting attention as novel therapeutic methods for inflammatory autoimmune diseases such as rheumatoid arthritis and ulcerative colitis. The physicochemical properties of intravenously administered nanomedicines enable them to target inflamed tissues passively. However, few studies have attempted to determine the influences of nanoparticle surface characteristics on inflammation site accumulation. Here, we aimed to study the effects of polyethylene glycol (PEG) modification and surface charge on liposome ability to accumulate in inflammatory sites and be uptake by macrophages. Four different liposome samples with different PEG modification and surface charge were prepared. Liposome accumulation in the inflammation sites of arthritis and ulcerative colitis model mice was evaluated by using in vivo imaging. There was greater PEG-modified than unmodified liposome accumulation at all inflammation sites. There was greater anionic than cationic liposome accumulation at all inflammation sites. The order in which inflammation site accumulation was confirmed was PEG-anionic > PEG-cationic > anionic > cationic. PEG-anionic liposomes had ~2.5× higher fluorescence intensity than PEG-cationic liposomes, and the PEG-liposomes had ~2× higher fluorescence intensity than non-PEG liposomes. All liposomes have not accumulated at the inflammation sites in healthy mice. Furthermore, cationic liposomes were taken up to ~10× greater extent by RAW264.7 murine macrophages. Thus, PEG-cationic liposomes that have the ability to accumulate in inflammatory sites via intravenous administration and to be taken up by macrophages could be useful.

Anti-Metastatic Effects on Melanoma via Intravenous Administration of Anti-NF-κB siRNA Complexed with Functional Peptide-Modified Nano-Micelles.

Controlling metastasis is an important strategy in cancer treatment. Nanotechnology and nucleic acids with novel modalities are promising regulators of cancer metastasis. We aimed to develop a small interfering RNA (siRNA) systemic delivery and anti-metastasis system using nanotechnology. We previously reported that polyethylene glycol-polycaprolactone (PEG-PCL) and functional peptide CH2R4H2C nano-micelle (MPEG-PCL-CH2R4H2C) has high siRNA silencing effects, indicated by increased drug accumulation in tumor-bearing mice, and has an anti-tumor effect on solid tumors upon systemic injection. In this study, we aimed to apply our micelles to inhibit metastasis and evaluated the inhibitory effect of anti-RelA siRNA (siRelA), which is a subunit of NF-κB conjugated with MPEG-PCL-CH2R4H2C, via systemic administration. We report that siRelA/MPEG-PCL-CH2R4H2C had a high cellular uptake and suppressed the migration/invasion of cells in B16F10 cells without toxicity. In addition, in a lung metastasis mouse model using intravenous administration of B16F10 cells treated with siRelA/MPEG-PCL-CH2R4H2C, the number of lung nodules in lung tissue significantly decreased compared to naked siRelA and siControl/MPEG-PCL-CH2R4H2C micelle treatments. Hence, we show that RelA expression can reduce cancer metastasis, and MPEG-PCL-CH2R4H2C is an effective siRNA carrier for anti-metastasis cancer therapies.

Correction: Therapeutic Effects in a Transient Middle Cerebral Artery Occlusion Rat Model by Nose-To-Brain Delivery of Anti-TNF-Alpha siRNA with Cell-Penetrating Peptide-Modified Polymer Micelles. Pharmaceutics, 2019, 11(9), 478.

The appropriate information for the reprint used with permission from [...].

Therapeutic Effects in a Transient Middle Cerebral Artery Occlusion Rat Model by Nose-To-Brain Delivery of Anti-TNF-Alpha siRNA with Cell-Penetrating Peptide-Modified Polymer Micelles.

We previously reported that siRNA delivery to the brain is improved by the nose-to-brain delivery route and by conjugation with polyethylene glycol-polycaprolactone (PEG-PCL) polymer micelles and the cell-penetrating peptide, Tat (PEG-PCL-Tat). In this study, we evaluated the nose-to-brain delivery of siRNA targeting TNF-α (siTNF-α) conjugated with PEG-PCL-Tat to investigate its therapeutic effects on a transient middle cerebral artery occlusion (t-MCAO) rat model of cerebral ischemia-reperfusion injury. Intranasal treatment was provided 30 min after infarction induced via suturing. Two hours after infarction induction, the suture was removed, and blood flow was released. At 22 h post-reperfusion, we assessed the infarcted area, TNF-α production, and neurological score to determine the therapeutic effects. The infarcted area was observed over a wide range in the untreated group, whereas shrinkage of the infarcted area was observed in rats subjected to intranasal administration of siTNF-α with PEG-PCL-Tat micelles. Moreover, TNF-α production and neurological score in rats treated by intranasal administration of siTNF-α with PEG-PCL-Tat micelles were significantly lower than those in untreated and naked siTNF-α-treated rats. These results indicate that nose-to-brain delivery of siTNF-α conjugated with PEG-PCL-Tat micelles alleviated the symptoms of cerebral ischemia-reperfusion injury.

Anti-RelA siRNA-Encapsulated Flexible Liposome with Tight Junction-Opening Peptide as a Non-invasive Topical Therapeutic for Atopic Dermatitis.

Small interfering RNA (siRNA) has been proposed as a novel treatment for atopic dermatitis (AD) because it suppresses sequence-specific mRNA expression. Indeed siRNA-based therapy achieves an almost complete cure with fewer side effects than currently available treatments. However, the tight junctions in the granular layer of the epidermis in the atopic skin are barriers to siRNA delivery. We previously reported the potential clinical utility of AT1002, a peptide that opens tight junctions. In the present study, we evaluated a topical siRNA-based therapy for AD using AT1002 in combination with a flexible liposome. The 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE)/cholesteryl hemisuccinate (CHEMS) liposome was chosen as a carrier for siRNA because of its highly flexible structure and permeability. We prepared siRNA-encapsulated DOPE/CHEMS liposomes and examined their physical properties, safety, uptake into RAW264.7 cells, and topical application in healthy and AD-affected skin. We then assessed the efficacy of anti-nuclear factor-kappa B (NF-κB) (RelA) siRNA (siRelA)-encapsulated DOPE/CHEMS liposomes with AT1002 in AD model mice. The siRNA-DOPE/CHEMS liposomes were absorbed significantly better than siRNA alone and they enhanced siRNA skin penetration without toxicity. Moreover, siRelA-DOPE/CHEMS liposomes with AT1002 alleviated AD symptoms and reduced the levels of inflammatory cytokines in AD model mice. Therefore, the combination of AT1002 and DOPE/CHEMS liposomes could be a dermally applied RNA interference therapeutic system for effective RNA delivery and AD treatment.

Transdermal anti-nuclear kappaB siRNA therapy for atopic dermatitis using a combination of two kinds of functional oligopeptide.

Nucleic acid-based targeting of nuclear factor kappaB (NF-κB) is gaining attention as a treatment option for skin diseases like atopic dermatitis (AD). Transdermal administration improves patient quality of life because of non-invasive; however, siRNA delivery into the skin can be challenging owing to the barrier of tight junctions in the granular layer. Therefore, we aimed to develop a delivery system of siRNA for topical skin application using functional peptides. We previously reported that combined treatment with a cytoplasm-responsive stearylated-arginine-rich peptide (STR-CH2R4H2C) and a tight junction opening peptide (AT1002) showed high siRNA permeability in the skin of AD-induced and normal mice. Here, we used murine macrophage RAW264.7 cells to examine siRNA permeation and the therapeutic effect of anti-NF-κB (RelA) siRNA (siRelA) complexed with STR-CH2R4H2C and AT1002 for AD-induced mice. We showed that significantly higher siRNA cellular uptake occurs after this treatment as well as decreased TNF-α and IL-6 expression. Additionally, we showed that effective siRNA transdermal delivery occurs with the suppression of the tight junction protein ZO-1. Moreover, topical skin application of siRelA with STR-CH2R4H2C and AT1002 improved AD-like symptoms in model mice. Thus, the combined treatment of STR-CH2R4H2C and AT1002 could serve as an effective transdermal siRNA therapeutic system for AD.

Intra-articular Retention and Anti-arthritic Effects in Collagen-Induced Arthritis Model Mice by Injectable Small Interfering RNA Containing Hydrogel.

Small interfering RNAs (siRNAs) are expected to offer a means of treating rheumatoid arthritis (RA) because they allow the specific silencing of genes related to RA pathogenesis. In our previous study, we reported that the siRNA targeted against RelA (anti-RelA siRNA), an important nuclear factor-kappaB (NF-κB) subdomain, was an effective therapeutic in atopic dermatitis and RA model animals. In this study, to develop an intra-articular injectable gel formulation against RA, we prepared a hydrogel that contains anti-RelA siRNA, and determined the in vitro release profile (%) and in vivo intra-articular retention of fluorescence-labeled model siRNA, and the anti-arthritic effects of the anti-RelA siRelA containing hydrogel in RA model mice. We selected the silk protein, sericin (SC), as an aqueous gel base, as it is a biocompatible and useful for forming hydrogels without a cross-linker. We showed that fluorescence-labeled model siRNA was continuously released from SC hydrogel in vitro, and retained in the knee joint of rats after injection of siRNA hydrogel. In addition, the knee joint thickness, clinical severity and incidence (%) in collagen-induced arthritis (CIA) mice as RA model treated with anti-RelA siRNA containing hydrogel were more improved than untreated, anti-RelA siRNA solution and negative control siRNA containing hydrogel group. Therefore, the intra-articular injectable sericin hydrogel formulation containing of anti-RelA siRNA could be a great potential therapeutic in rheumatoid arthritis.

Enhancement of nose-to-brain delivery of hydrophilic macromolecules with stearate- or polyethylene glycol-modified arginine-rich peptide.

Recently, nose-to-brain delivery is a highly versatile route, which, in combination with novel drugs being developed for treating intractable CNS diseases, is a promising approach for the treatment of disorders. Furthermore, nano-sized drug carriers may improve nose-to-brain drug delivery by their capability to increase the transmucosal penetration of the drugs across nasal mucosal tissue barrier. However, there is still not enough information regarding mechanism of absorption pathway from nasal cavity to brain using nanocarriers. In this study, to investigate the nose-to-brain transport pathway using nanocarriers, the distribution in whole brain, nasal mucosa, and trigeminal nerve after intranasal administration of two kinds of nanocarriers which have hydrophobic or hydrophilic moiety. We used CHHRRRRHHC peptide (CH2R4H2C) as basic peptide carriers, and modified with stearic acid (STR) as a hydrophobic moiety (STR-CH2R4H2C) or polyethylene glycol (PEG)-based block copolymer (PEG-PCL) as hydrophilic moiety (PEG-PCL-CH2R4H2C). The nose-to-brain drug delivery can be improved by using STR-CH2R4H2C and PEG-PCL-CH2R4H2C as carriers. Specifically, hydrophobic STR-CH2R4H2C is more suitable for the transport of drugs targeting the forebrain, while PEG-PCL-modified CH2R4H2C is more suitable for transporting drugs targeting the hindbrain or whole brain tissue. In conclusion, the results of this study support the possibility that drug delivery pathways can be controlled depending on the properties of different carrier complexes.

Systemic delivery of small interfering RNA targeting nuclear factor κB in mice with collagen-induced arthritis using arginine-histidine-cysteine based oligopeptide-modified polymer nanomicelles.

This study aimed to build an innovative system to deliver a systemic small interfering RNA (siRNA) treatment for rheumatoid arthritis. We combined arginine-histidine-cysteine based oligopeptide-modified polymer micelles with siRNA targeting the nuclear factor κB subunit, RelA (siRelA). This is a key molecule in the control of inflammation. We tested the cellular uptake of siRNA and its effects on inflammatory cytokine levels in vitro using synoviocytes, and siRNA distribution and therapeutic effects in vivo in mice with collagen-induced arthritis (CIA). These studies showed that arginine-histidine based oligopeptide modified micelles produced effective cellular siRNA uptake and suppressed inflammatory cytokine levels in synoviocytes. In vivo, these micelles produced marked accumulation of siRNAs in arthritic paws in CIA mice, with much less accumulation in healthy mice. The siRelA-polymer micelle complexes also produced more effective suppression of RelA mRNA expression and inflammatory cytokine levels in the arthritic paws of CIA mice and reduced their clinical symptom scores and paw thickness.

Development of an Innovative Intradermal siRNA Delivery System Using a Combination of a Functional Stearylated Cytoplasm-Responsive Peptide and a Tight Junction-Opening Peptide.

As a new category of therapeutics for skin diseases including atopic dermatitis (AD), nucleic acids are gaining importance in the clinical setting. Intradermal administration is noninvasive and improves patients' quality of life. However, intradermal small interfering RNA (siRNA) delivery is difficult because of two barriers encountered in the skin: intercellular lipids in the stratum corneum and tight junctions in the stratum granulosum. Tight junctions are the major barrier in AD; therefore, we focused on functional peptides to devise an intradermal siRNA delivery system for topical skin application. In this study, we examined intradermal siRNA permeability in the tape-stripped (20 times) back skin of mice or AD-like skin of auricles treated with 6-carboxyfluorescein-aminohexyl phosphoramidite (FAM)-labeled siRNA, the tight junction modulator AT1002, and the functional cytoplasm-responsive stearylated peptide STR-CH2R4H2C by using confocal laser microscopy. We found that strong fluorescence was observed deep and wide in the epidermis and dermis of back skin and AD-like ears after siRNA with STR-CH2R4H2C and AT1002 treatment. After 10 h from administration, brightness of FAM-siRNA was significantly higher for STR-CH2R4H2C + AT1002, compared to other groups. In addition, we confirmed the nontoxicity of STR-CH2R4H2C as a siRNA carrier using PAM212 cells. Thus, our results demonstrate the applicability of the combination of STR-CH2R4H2C and AT1002 for effective intradermal siRNA delivery.

Topical Anti-Nuclear Factor-Kappa B Small Interfering RNA with Functional Peptides Containing Sericin-Based Hydrogel for Atopic Dermatitis.

The small interfering RNA (siRNA) is suggested to offer a novel means of treating atopic dermatitis (AD) because it allows the specific silencing of genes related to AD pathogenesis. In our previous study, we found that siRNA targeted against RelA, an important nuclear factor-kappa B (NF-κB) subdomain, with functional peptides, showed therapeutic effects in a mouse model of AD. In the present study, to develop a topical skin application against AD, we prepared a hydrogel containing anti-RelA siRNA and functional peptides and determined the intradermal permeation and the anti-AD effects in an AD mouse model. We selected the silk protein, sericin (SC), which is a versatile biocompatible biomaterial to prepare hydrogel as an aqueous gel base. We found that the siRNA was more widely delivered to the site of application in AD-induced ear skin of mice after topical application via the hydrogel containing functional peptides than via the preparation without functional peptides. In addition, the ear thickness and clinical skin severity of the AD-induced mice treated with hydrogel containing anti-RelA siRNA with functional peptides improved more than that of mice treated with the preparation formulated with negative siRNA.

Functional peptide nanocarriers for delivery of novel anti-RelA RNA interference agents as a topical treatment of atopic dermatitis.

Small interfering RNAs (siRNAs) are a potential treatment of atopic dermatitis (AD) because they can specifically silence the gene expression of AD-related factors. However, siRNA alone cannot exert a sufficiently strong therapeutic effect due to low delivery efficiency to the target tissues and cells; simply increasing the amount used is not possible due to the possibility of off-target effects. We previously reported a novel class of therapeutic RNA interference (RNAi) agents called nkRNA(®) and PnkRNA(®), which have been shown to be effective in several disease models, have greater resistance to nuclease degradation than canonical siRNAs, and do not induce any immunotoxicity. In the present study, we describe a non-invasive and effective transdermal RNAi therapeutic system for atopic dermatitis that uses the functional cell-penetrating stearoyl-oligopeptide OK-102 as a cytoplasm-responsive nanocarrier for nkRNA(®) and PnkRNA(®). The two RNAi agents were targeted against RelA, a subclass of NF-κB (nuclear factor kappa B), and, as part of OK-102 complexes, they strongly silenced RelA mRNA in macrophage cells and demonstrated a significant therapeutic effect in a mouse model of AD. It was shown that OK-102-complexed RNAi agents were an efficient therapeutic system for AD and caused no adverse reactions.

Cytoplasm-responsive nanocarriers conjugated with a functional cell-penetrating peptide for systemic siRNA delivery.

To develop a gene carrier for cancer therapy by systemic injection, we synthesized methoxypolyethylene glycol-polycaprolactone (MPEG-PCL) diblock copolymers conjugated with a cytoplasm-responsive cell-penetrating peptide (CPP), CH2R4H2C (C, Cys; H, His; R, Arg). The carrier/small interfering RNA (siRNA) complexes (N/P ratio of 20) had a particle size of approximately 50 nm and stabilized the siRNA against RNase. The cellular uptake ability of the carrier/FAM-siRNA complexes with fetal bovine serum was significantly higher than that of naked FAM-siRNA. In addition, the carrier/anti-vascular endothelial growth factor siRNA (siVEGF) complexes attained a significantly greater silencing effect than naked siVEGF with low cytotoxicity, resulting from higher uptake, early endosomal escape, and efficient release from the complexes in the cytoplasm. Furthermore, intravenous injection of MPEG-PCL-CH2R4H2C/siVEGF complexes had a significantly higher anti-tumor effect in S-180 tumor-bearing mice, which could be attributed to the rigid compaction of siRNA by ionic interactions and disulfide linkages in the CPP polymer micelles in the blood, as well as higher release following cleavage of the disulfide bonds in the reductive cytosol. Taken together, our data demonstrated that these cytoplasm-responsive polymer micelles conjugated with multi-functional CPP, could facilitate siVEGF delivery to tumor tissues after systemic injection and could exert an extremely strong anti-tumor effect.

Measurement of agitation force in dissolution test and mechanical destructive force in disintegration test.

The purpose of this study was to investigate the effect of the agitation force and mechanical destructive force on the drug dissolution of a tablet in the paddle rotation dissolution test and in the disintegration test. The agitation in the paddle method and the mechanical destructive force in the disintegration test were considered to be conclusive factors for drug dissolution. The dissolution rate of planar-constant-release tablets increased with increasing paddle rotation speed and increased with increasing distance from the center of the vessel bottom. Separately, the fluid resistance (agitation force) in the vessel was measured using a modified paddle method apparatus equipped with a fluid resistance sensor. The fluid resistance was 0.03 x 10(-3) N/(64 mm(2)) when the paddle rotation speed was 50 rpm at a position 4 mm away from the center. A considerable position-dependent change in agitation force intensity was seen with the fluid resistance sensor. The impulsive force (mechanical destructive force) in the disintegration test apparatus was measured using a modified basket-rack assembly with a strain gauge transducer. The fluid resistance was measured using the basket-rack assembly with a different sensor probe and amplifier. The impulsive force applied by the auxiliary disk was 0.31 N and the fluid resistance at the bottom of the basket-rack assembly was 1.66 x 10(-3) N/(64 mm(2)).

Comparison of the mechanical destructive force in the small intestine of dog and human.

The purpose of this study was to evaluate the destructive force that oral solid dosage forms receive in the small intestine of dogs and humans. Information on the mechanical destructive forces of the gastrointestinal tract (GI) helps formulation design research in the following way: (1) to improve the predictability of the dissolution test since in vivo drug release is affected by not only agitation intensity but also mechanical stress; (2) to design safe and robust products by avoiding dose-dumping or unintended drug release at an inadequate site; (3) to better understand the species difference in bioavailability by comparing the destructive forces against dosage forms in the GI of dogs with those of humans. "Destructive force Dependent Release System" (DDRS) was developed to measure the mechanical destructive forces of the GI tract by using highly hydrophobic Teflon powder. In a DDRS, a marker drug contained in the core tablet is released only when the DDRS receives a force larger than its pre-determined crushing strength. DDRS-Small Intestine (DDRS-SI), a modified DDRS, was prepared for targeting the small intestine. DDRS-SI was encapsulated in starch capsules (Capill) and then the capsules were coated with an enteric film (DDRS-SI-Ecap). The capsules were administered to six dogs and nine human volunteers. Both dogs and human volunteers crushed a DDRS-SI having a crushing strength of 1.2 N. Therefore, these controlled-release formulations should withstand a destructive force of 1.2 N when they pass through the small intestine.