Aminoclay as a highly effective cationic vehicle for enhancing adenovirus-mediated gene transfer through nanobiohybrid complex formation

Organometallic Phyllosilicate-Gold Nanocomplex: An Effective Oral Delivery System of Methotrexate for Enhanced in vivo Efficacy Against Colorectal Cancer

Purpose

Oral administration, although convenient and preferred for treating colorectal cancer (CRC), faces challenges due to limited CRC-related intestinal positioning and a dense mucus barrier. In the present study, a gold-nanoparticle decorated-organometallic phyllosilicate nanocomposite (AC-Au), with a pH-dependent surface coating, was employed for more effective oral delivery of anticancer drugs to treat CRC.

Methods

The organometallic AC-Au was synthesized using the in-situ sol-gel method. Subsequently, methotrexate (MTX) was loaded into AC-Au, and the complex (AC-Au/MTX) was surface-coated with poly (methacrylic acid-co-methyl methacrylate) (1:2), a pH-dependent polymer (E/AC-Au /MTX). The in vitro characteristics of nanoparticles were examined using various analytical methods. In vivo efficacy studies were also conducted using an HCT-116 orthotopic colorectal cancer model.

Results

AC-Au emerged as a spherical nanoparticle with a mean size of 26.5 ± 0.43 nm, displaying a positive charge over the pH range of 2-10. Both the uncoated and coated drug-loaded nanocomplexes (AC-Au/MTX and E/AC-Au/MTX) were fabricated with high entrapment efficiency (> 80%). Various analyses, including ultraviolet-visible spectroscopy, X-ray powder diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy, confirmed the formation of the nanocomplexes. While AC-Au/MTX achieved rapid and extensive drug release at the pH range of 1.2-7.4, E/AC-Au/MTX exhibited pH-dependent drug release, with approximately 23% at pH 1.2 and 74% at pH 7.4. Relative to free MTX, the AC-Au-based nanocomplex significantly enhanced the cytotoxicity of MTX in HCT-116 cells. Furthermore, orally administered E/AC-Au/MTX significantly improved the anti-tumor activity of MTX in an HCT-116 orthotopic colorectal cancer model, resulting in approximately 60% suppression of tumor mass compared with the positive control.

Conclusion

The organometallic AC-Au nanocomplex coated with a pH-dependent polymer has the potential to be an effective colonic drug delivery system of MTX, enhancing in vivo efficacy against colorectal cancer.

A Novel Bioimplant Comprising Ad-BMP9-Transfected BMSCs and GelMA Microspheres Produced from Microfluidic Devices for Bone Tissue Engineering

Oral and maxillofacial bone defect repair in patients remains challenging in clinical treatment due to the different morphologies of bone defects. An injectable hydrogel of microspheres with sustained bone morphogenetic protein 9 (BMP9) expression for oral and maxillofacial bone defect repair has been developed. This study is bioinspired by the substantial osteogenesis property of recombinant adenoviruses expressing bone morphogenetic protein 9 (Ad-BMP9) and minimally invasive treatment by injection. A novel scaffold encompassing bone mesenchymal stem cells (BMSCs) transfected with Ad-BMP9 was produced and cocultured on a superficial surface of monodisperse photocrosslinked methacrylate gelatin hydrogel microspheres (GelMA/MS, produced with microfluidic technology). The biological tests including live/dead cell staining, phalloidin staining, cell counting kit-8 (CCK-8) assay, alkaline phosphatase (ALP) activity and staining, alizarin red S staining, and quantitative real-time polymerase chain reaction (RT-qPCR), revealed that the hydrogel microspheres exhibited good biocompatibility and remarkably promoted the osteogenic differentiation of BMSCs in vitro. In addition, a small needle was injected the innovative scaffold beneath the nude mice's skin. The micro-CT and histological staining assay results demonstrated that the new implant, with high blood vessel formation markers (CD31-positive cells) expression over four and eight weeks, achieved significant vascularized bone-like tissue formation. Consequently, the injectable hydrogel microspheres, cocultured with BMSC transfected with Ad-BMP9, enhanced vascularized bone regeneration, therefore representing a facile and promising technique for the minimally invasive treatment of oral and maxillofacial bone defects.

Aminoclay Nanoparticles Induce Anti-Inflammatory Dendritic Cells to Attenuate LPS-Elicited Pro-Inflammatory Immune Responses

Although 3-aminopropyl functionalized magnesium phyllosilicate nanoparticles (hereafter aminoclay nanoparticles, ACNs) are well-known nanomaterials employed as drug carriers, their effects on immune cells remain unclear. To address this issue, we explored murine dendritic cells (DCs) as these cells belong to the innate arm of the immune system and function as antigen-presenting cells to elicit adaptive immune responses. We examined the in vitro effects of ACNs on DCs isolated from B6 mice. ACN treatment significantly down-regulated the expression of inflammasome-related markers, including NLRP3, caspase-1, and IL1β. The ACNs-induced anti-inflammatory DC phenotype was further confirmed by down-regulation of the AKT/mTOR/HIF1α signaling pathway. Such anti-inflammatory effects of ACNs on DCs occurred independently of DC subtypes. To document the effects of ACNs on DCs more clearly, we examined their anti-inflammatory effects on lipopolysaccharide (LPS)-activated DCs. As expected, excessive inflammatory responses (increased mitochondrial ROS and Th1-type cytokines such as IL12 and IL1β) of LPS-activated DCs were dramatically attenuated by ACN treatment. Furthermore, ACNs down-regulated IFNγ production by antigen-specific CD4⁺ T cells, which is consistent with a reduced inflammatory phenotype of DCs. Overall, our results provide support for employing ACNs as drug delivery materials with therapeutic potential to control inflammatory disorders.

Aluminum particles generated during millisecond electric pulse application enhance adenovirus-mediated gene transfer in L929 cells

Gene electrotransfer is an attractive method of non-viral gene delivery. However, the mechanism of DNA penetration across the plasma membrane is widely discussed. To explore this process for even larger structures, like viruses, we applied various combinations of short/long and high/low-amplitude electric pulses to L929 cells, mixed with a human adenovirus vector expressing GFP. We observed a transgene expression increase, both in the number of GFP-converted cells and GFP levels, when we added a low-voltage/millisecond-pulse treatment to the adenovirus/cell mixture. This increase, reflecting enhanced virus penetration, was proportional to the applied electric field amplitude and pulse number, but was not associated with membrane permeabilization, nor to direct cell modifications. We demonstrated that this effect is mainly due to adenovirus particle interactions with aggregated aluminum particles released from energized electrodes. Indeed, after centrifugation of the pulsed viral suspension and later on addition to cells, the activity was found mainly associated with the aluminum aggregates concentrated in the lower fraction and was proportional to generated quantities. Overall, this work focused on the use of electrotransfer to facilitate the adenovirus entry into cell, demonstrating that modifications of the penetrating agent can be more important than modifications of the target cell for transfer efficacy.

Effects of Gene Delivery Approaches on Differentiation Potential and Gene Function of Mesenchymal Stem Cells

Introduction of a gene to mesenchymal stem cells (MSCs) is a well-known strategy to purposely manipulate the cell fate and further enhance therapeutic performance in cell-based therapy. Viral and chemical approaches for gene delivery interfere with differentiation potential. Although microinjection as a physical delivery method is commonly used for transfection, its influence on MSC cell fate is not fully understood. The current study aimed to evaluate the effects of four nonviral gene delivery methods on stem cell multi-potency. The four delivery methods are robotic microinjection, polyethylenimine (PEI), cationic liposome (cLipo), and calcium phosphate nanoparticles (CaP). Among the four methods, microinjection has exhibited the highest transfection efficiency of ~60%, while the three others showed lower efficiency of 10-25%. Robotic microinjection preserved fibroblast-like cell morphology, stress fibre intactness, and mature focal adhesion complex, while PEI caused severe cytotoxicity. No marked differentiation bias was observed after microinjection and cLipo treatment. By contrast, CaP-treated MSCs exhibited excessive osteogenesis, while PEI-treated MSCs showed excessive adipogenesis. Robotic microinjection system was used to inject the CRISPR/Cas9-encoding plasmid to knock out PPAR gene in MSCs, and the robotic microinjection did not interfere with PPAR function in differentiation commitment. Meanwhile, the bias in osteo-adipogenic differentiation exhibited in CaP and PEI-treated MSCs after PPAR knockout via chemical carriers. Our results indicate that gene delivery vehicles variously disturb MSCs differentiation and interfere with exogenous gene function. Our findings further suggest that robotic microinjection offers a promise of generating genetically modified MSCs without disrupting stem cell multi-potency and therapeutic gene function.

Nanocomposites-based targeted oral drug delivery systems with infliximab in a murine colitis model

BACKGROUND

Infliximab (IFX), a TNF-α blocking chimeric monoclonal antibody, induces clinical response and mucosal healing in patients with inflammatory bowel disease (IBD). However, systemic administration of this agent causes unwanted side effects. Oral delivery of antibody therapeutics might be an effective treatment strategy for IBD compared to intravenous administration.

RESULTS

All three carriers had a high encapsulation efficiency, narrow size distribution, and minimal systemic exposure. There was a higher interaction between nanocomposite carriers and monocytes compared to lymphocytes in the PBMC of IBD patients. Orally administered nanocomposite carriers targeted to inflamed colitis minimized systemic exposure. All IFX delivery formulations with nanocomposite carriers had a significantly less colitis-induced body weight loss, colon shortening and histomorphological score, compared to the DSS-treated group. AC-IFX-L and EAC-IFX-L groups showed significantly higher improvement of the disease activity index, compared to the DSS-treated group. In addition, AC-IFX-L and EAC-IFX-L alleviated pro-inflammatory cytokine expressions (Tnfa, Il1b, and Il17).

CONCLUSION

We present orally administered antibody delivery systems which improved efficacy in murine colitis while reducing systemic exposure. These oral delivery systems suggest a promising therapeutic approach for treating IBD.

Talc-like hybrids: influence of the synthesis

Adding water to the synthesis medium leads to the formation of hybrids with low polycondensation, high crystallinity and high thermal stability.

Development of pH-responsive organic-inorganic hybrid nanocomposites as an effective oral delivery system of protein drugs

This research aimed to develop a pH-responsive organic-inorganic hybrid nanocomposite as an effective oral delivery system for protein drugs. Three different nanocomposites were prepared by using bovine serum albumin (BSA) as a model protein. A nanocomplex of BSA with 3-aminopropyl functionalized magnesium phyllosilicate (AC-BSA) was obtained via the spontaneous co-assembly and then sequentially coated with glycol-chitosan (GAC-BSA) and the pH sensitive polymer, Eudragit®L100-55 (EGAC-BSA). These organic-inorganic hybrid nanocomposites exhibited high entrapment efficiency (86-99%) and their structural characteristics were confirmed by using energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and circular dichroism analysis, indicating that the secondary structure of BSA was well retained in the nanocomposites. At pH 1.2, AC-BSA achieved rapid drug release of about 80% within 2 h, while GAC-BSA and EGAC-BSA exhibited slow drug release of 30% and 15%, respectively, indicating that the surface-coated nanocomposites were more stable in the gastric condition. Furthermore, the conformational stability of BSA entrapped in EGAC-BSA was well retained in the presence of proteolytic enzymes, suggesting that EGAC-BSA should be effective in protecting the protein against gastrointestinal harsh environment. Compared to free BSA, all of tested nanocomposites demonstrated 2.1-3.8-fold higher cellular uptake in Caco-2 cells. Furthermore, energy-dependent endocytosis and paracellular pathway contributed to the cellular transport of nanoparticles. After oral administration in rats, EGAC-BSA significantly enhanced the intestinal permeation of BSA compared to free BSA. In conclusion, EGAC-BSA appears to be promising as an effective oral delivery system for proteins with enhanced intestinal absorption.

LAPONITE® nanoplatform functionalized with histidine modified oligomeric hyaluronic acid as an effective vehicle for the anticancer drug methotrexate

The synthetic clay material, LAPONITE® (LAP), having a nanodisk structure together with a negatively charged surface, has been used for effective drug encapsulation by virtue of its interlayer space. In this research effort, the LAP nanodisk was used for the first time to encapsulate the antifolic methotrexate (MTX); the MTX-loaded LAP nanodisks (LAP/MTX) demonstrated a high drug loading efficiency of 80.39%. An efficient and reliable tumor-targeting device that rests on the synthesized oligomeric hyaluronic acid-l-histidine (oHA-His) was then encapsulated in the MTX-loaded LAP disks (forming LAP/MTX/oHA-His nanohybrids). The drug released from the LAP/MTX/oHA-His nanohybrids was pH-dependent and matched the first-order kinetics that describes the diffusion mechanism. In vitro biological evaluation manifested that the MTX-loaded LAP nanocarriers, particularly the LAP/MTX/oHA-His nanohybrids that have targetability and lysosomal antineoplastic activity, can be effectively internalized by the MCF-7 cell line, and can exhibit a more prominent anticancer cytotoxicity than free MTX. In vivo studies with mice indicated that the LAP/MTX/oHA-His nanohybrids demonstrated much higher antitumor efficiency compared to the LAP/MTX nanohybrids and pure MTX. Taken together, the LAP/oHA-His, CD44 receptor targeting and pH-sensitive multifunctional nanohybrids conferred the MTX with excellent cytocompatibility, dispersion stability, sustained pH-responsive release properties, and improved anticancer activity, and may be further developed as a potential active nanoplatform for various anticancer drugs.

Electrostatic interaction of tumor-targeting adenoviruses with aminoclay acquires enhanced infectivity to tumor cells inside the bladder and has better cytotoxic activity

In a previous report, 3-aminopropyl functionalized magnesium phyllosilicate (aminoclay) improved adenovirus transduction efficiency by shielding the negative surface charges of adenovirus particles. The present study analyzed the physicochemical characterization of the electrostatic complex of adenoviruses with aminoclay and explored whether it could be utilized for enhancing tumor suppressive activity in the bladder. As a result of aminoclay-adenovirus nanobiohybridization, its transduction was enhanced in a dose-dependent manner, increasing transgene expression in bladder cancer cells and in in vivo animal models. Physicochemical studies demonstrated that positively charged aminoclay led to the neutralization of negative surface charges of adenoviruses, protection of adenoviruses from neutralizing antibodies and lowered transepithelial electrical resistance (TEER). As expected from the physicochemical properties, the aminoclay enabled tumor-targeting adenoviruses to be more potent in killing bladder cancer cells and suppressing tumor growth in orthotopic bladder tumors, suggesting that aminoclay would be an efficient, versatile and biocompatible delivery carrier for intravesical instillation of adenoviruses.

Organic–inorganic hybrids having a talc-like structure as suitable hosts to guest a wide range of species

The sol–gel process involving hydrolysis and condensation reactions is an attractive way to form siloxane based hybrid materials since it is a one-step method performed under mild conditions.

Optimization and physicochemical characterization of a cationic lipid-phosphatidylcholine mixed emulsion formulated as a highly efficient vehicle that facilitates adenoviral gene transfer

Cationic lipid-based nanoparticles enhance viral gene transfer by forming electrostatic complexes with adenoviral vectors. We recently demonstrated the superior complexation capabilities of 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) emulsion compared with a liposomal counterpart but the cytotoxicity of DOTAP emulsions remained a challenge. The present study is aimed at formulating an emulsion capable of acting as a highly effective viral gene transfer vehicle with reduced cytotoxicity and to physicochemically characterize the structures of virus-emulsion complexes in comparison with virus-liposome complexes when the only difference between emulsions and liposomes was the presence or absence of inner oil core. The emulsion formulation was performed by 1) reducing the content of DOTAP while increasing the content of zwitterionic lipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), and 2) optimizing the oil content. The complexation capability of formulated DOTAP:DMPC mixed emulsions was similar to those of emulsions containing DOTAP alone while displaying significantly lower cytotoxicity. The complexation capabilities of the DOTAP:DMPC mixed emulsion were serum-compatible and were monitored in a variety of cell types, whereas its liposomal counterpart was totally ineffective. Characterization by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and dynamic light scattering studies indicated that the optimized emulsions spontaneously surrounded the virus particles to generate emulsions that encapsulated the viral particles, whereas viral particles merely attached to the surfaces of the counterpart liposomes to form multiviral aggregates. Overall, these studies demonstrated that optimized DOTAP:DMPC mixed emulsions are potentially useful for adenoviral gene delivery due to less cytotoxicity and the unique ability to encapsulate the viral particle, highlighting the importance of nanoparticle formulation.

The healing of alveolar bone defects with novel bio-implants composed of Ad-BMP9-transfected rDFCs and CHA scaffolds

Cells, scaffolds, and growth factors play important roles in bone regeneration. Bone morphogenetic protein 9 (BMP9), a member of BMP family, could facilitate osteogenesis by regulating growth factors and promoting angiogenesis. Similar to other stem cells, rat dental follicle stem cells (rDFCs), the precursor cells of cementoblasts, osteoblasts and periodontal ligament cells, can self-renew and exhibit multipotential capacity. Coralline hydroxyapatite (CHA) has good biocompatibility and conductivity required for bone tissue engineering. Here, we reported that BMP9 could enhance the osteogenic differentiation of rDFCs in cell culture. Moreover, our results suggested that BMP9 acted through the Smad1/5/8 signaling pathway. We also produced a novel scaffold that encompasses bio-degradable CHA seeded with recombinant adenoviruses expressing BMP9-transfected rDFCs (Ad-BMP9-transfected rDFCs). With this implant, we achieved more alveolar bone regeneration in the alveolar bone defect compared to blank group, CHA group and rDFCs group. Our results provided a novel bio-implants composed of Ad-BMP9-transfected rDFCs and CHA scaffolds and its mechanism is regarding the activation of Smad1/5/8 signaling pathway in BMP9-induced rDFCs osteogenesis.