The Serum-Resistant Transfection Evaluation and Long-Term Stability of Gene Delivery Dry Powder Based on Mesoporous Silica Nanoparticles and Polyethyleneimine by Freezing-Drying

Physical characteristics and stability profile of recombinant plasmid DNA within a film matrix

Plasmids are essential source material for production of biological drugs, vaccines and vectors for gene therapy. They are commonly formulated as frozen solutions. Considering the cost associated with maintenance of cold chain conditions during storage and transport, there is a significant need for alternative methods for stabilization of plasmids at ambient temperature. The objective of these studies was to identify a film-based formulation that preserved transfection efficiency of plasmids at 25 °C. A model plasmid, pAAVlacZ, was used for these studies. Transfection efficiency and agarose gel electrophoresis were utilized to assess bioactivity and changes in physical conformation of plasmid during storage. An amino acid, capable of sustaining a positive charge while supporting an alkaline environment within the film matrix, preserved transfection efficiency for 9 months at 25 °C. Addition of sugar and a plasticizer to the formulation preserved the plasmid in an amorphous state and improved handling properties of the film. The manner in which excipients were incorporated into bulk formulations and environmental humidity in which films were stored significantly impacted transfection efficiency of plasmid in the rehydrated solution. Taken together, these results suggest that plasmids can be stored for extended periods of time without refrigeration within a film matrix.

Generating Human Induced Pluripotent Stem Cell Via Low-Dose Polyethylenimine-Mediated Transfection: An Optimized Protocol

Human dermal fibroblasts (HDFs) can be reprogrammed through different strategies to generate human induced pluripotent stem cells (hiPSCs). However, most of these strategies require high-cost materials and specific equipment not readily accessible in most laboratories. Hence, liposomal and virus-based techniques can replace with polyethylenimine (PEI)-mediated transfection to overcome these challenges. However, few researchers have addressed the PEI's ability to transfect HDFs. This study used PEI reagent to transfer oriP/EBNA1-based vector into HDFs to produce hiPSC lines. We first described conditions allowing the efficient transfection of HDFs with low cytotoxicity and without specific types of equipment and optimized several parameters relevant to the transfection procedure. We then monitored the effect of different N/P ratios on transfection efficiency and cytotoxicity using flow cytometry and fluorescent microscopy. By the results, we found that transfection efficiency was greatly affected by plasmid DNA concentration, PEI concentration, order of combining reagents, serum presence in polyplexes, and the duration of serum starvations. Moreover, using the optimized condition, we found that the N/P ratio of 3 achieved the highest percentage of HDFs positive for green fluorescent protein plasmid (∼40%) with minimal cell toxicity. We finally generated hiPSCs using the optimized protocol and oriP/EBNA1-based vectors. We confirmed hiPSC formation by characterizing tests: alkaline phosphatase staining, immunocytochemistry assay, real-time PCR analysis, in vitro differentiation into three germ layers, and karyotyping test. In conclusion, our results indicated that 25 kDa branched PEI could efficiently transfect HDFs toward generating hiPSCs via a simple, cost-effective, and optimized condition.

Recent Advances in Nanoparticle-Based Co-Delivery Systems for Cancer Therapy

Cancer therapies have advanced tremendously throughout the last decade, yet multiple factors still hinder the success of the different cancer therapeutics. The traditional therapeutic approach has been proven insufficient and lacking in the suppression of tumor growth. The simultaneous delivery of multiple small-molecule chemotherapeutic drugs and genes improves the effectiveness of each treatment, thus optimizing efficacy and improving synergistic effects. Nanomedicines integrating inorganic, lipid, and polymeric-based nanoparticles have been designed to regulate the spatiotemporal release of the encapsulated drugs. Multidrug-loaded nanocarriers are a potential strategy to fight cancer and the incorporation of co-delivery systems as a feasible treatment method has projected synergistic benefits and limited undesirable effects. Moreover, the development of co-delivery systems for maximum therapeutic impact necessitates better knowledge of the appropriate therapeutic agent ratio as well as the inherent heterogeneity of the cancer cells. Co-delivery systems can simplify clinical processes and increase patient quality of life, even though such systems are more difficult to prepare than single drug delivery systems. This review highlights the progress attained in the development and design of nano carrier-based co-delivery systems and discusses the limitations, challenges, and future perspectives in the design and fabrication of co-delivery systems.

Efficient transfection and long-term stability of rno-miRNA-26a-5p for osteogenic differentiation by large pore sized mesoporous silica nanoparticles

MicroRNA (miRNA) based therapy for bone repair has shown promising results for regulating stem cell proliferation and differentiation, an efficient and stable vector for delivery of microRNA delivery is needed. The present study explored the stability and functionality of lyophilized mesoporous silica nanoparticles with core-cone structure and coated with polyethylenimine (MSN-CC-PEI) as a system for delivering Rattus norvegicus (rno)-miRNA-26a-5p into rat marrow mesenchymal cells (rBMSCs) to promote their osteogenic differentiation. We assessed the cellular uptake and transfection efficiency of nanoparticles loaded with labelled miRNA using confocal laser scanning microscopy and flow cytometry, and the cell viability using the MTT assay. The expression levels of osteogenic genes after one and two weeks were analysed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Extracellular matrix deposition and mineralization at 3 weeks were evaluated using Picro Sirius red and Alizarin red staining. We also assessed the performance of the delivery system after long term storage, by freeze drying rno-miRNA-26a-5p@MSN-CC-PEI with 5% trehalose and keeping them at -30 °C for 3 and 6 months. Osteogenic differentiation, matrix deposition, and mineralization were all significantly increased by rno-miRNA-26a-5p. In addition, this enhancement was not significantly altered by lyophilization and storage. Overall, these findings support the concept of MSN-CC-PEI as a delivery system for gene therapy. The complex of rno-miRNA-26a-5p@MSN-CC-PEI could efficiently transfect rBMSCs and enhance their osteogenic differentiation. In addition, the lyophilized complexes remain functional after 6 months of storage.

Special Focus Issue Part II: Recruitment of solid lipid nanoparticles for the delivery of CRISPR/Cas9: primary evaluation of anticancer gene editing

Aim: The CRISPR/Cas9 system is a promising gene-editing tool for various anticancer therapies; however, development of a biocompatible, nonviral and efficient delivery of CRISPR/Cas9 expression systems remains a challenge. Materials & methods: Solid lipid nanoparticles (SLNs) were produced based on pseudo and 3D ternary plots. Obtained SLNs and their complexes with PX458 plasmid DNA were characterized and evaluated in terms of cytotoxicity and transfection efficiency. Results: SLNs were found to be nanosized, monodispersed, stable and nontoxic. Furthermore, they revealed similar transfection efficiency as the positive control. Conclusion: Overall, we have achieved a good SLN basis for CRISPR/Cas9 delivery and have the potential to produce SLNs with targeted anticancer properties by modifying production parameters and components to facilitate translating CRISPR/Cas9 into preclinical studies.

Silica-Based Gene Delivery Systems: From Design to Therapeutic Applications

Advances in gene therapy have been foreshadowing its potential for the treatment of a vast range of diseases involving genetic malfunctioning. However, its therapeutic efficiency and successful outcome are highly dependent on the development of the ideal gene delivery system. On that matter, silica-based vectors have diverted some attention from viral and other types of non-viral vectors due to their increased safety, easily modifiable structure and surface, high stability, and cost-effectiveness. The versatility of silane chemistry and the combination of silica with other materials, such as polymers, lipids, or inorganic particles, has resulted in the development of carriers with great loading capacities, ability to effectively protect and bind genetic material, targeted delivery, and stimuli-responsive release of cargos. Promising results have been obtained both in vitro and in vivo using these nanosystems as multifunctional platforms in different potential therapeutic areas, such as cancer or brain therapies, sometimes combined with imaging functions. Herein, the current advances in silica-based systems designed for gene therapy are reviewed, including their main properties, fabrication methods, surface modifications, and potential therapeutic applications.

Mesoporous Silica Nanoparticles for Co-Delivery of Drugs and Nucleic Acids in Oncology: A Review

Mesoporous silica nanoparticles have attracted much attention in recent years as drug and gene delivery systems for biomedical applications. Among their most beneficial features for biomedicine, we can highlight their biocompatibility and their outstanding textural properties, which provide a great loading capacity for many types of cargos. In the context of cancer nanomedicine, combination therapy and gene transfection/silencing have recently been highlighted as two of its most promising fields. In this review, we aim to provide an overview of the different small molecule drug-nucleic acid co-delivery combinations that have been developed using mesoporous silica nanoparticles as carriers. By carefully selecting the chemotherapeutic drug and nucleic acid cargos to be co-delivered by mesoporous silica nanoparticles, different therapeutic goals can be achieved by overcoming resistance mechanisms, combining different cytotoxic mechanisms, or providing an additional antiangiogenic effect. The examples here presented highlight the great promise of this type of strategies for the development of future therapeutics.

A Drug Release Model Constructed by Factorial Design to Investigate the Interaction Between Host Mesoporous Silica Carriers and Drug Molecules

A drug release model based on mesocellular foam silica (MCF) for Biopharmaceutics Classification System (BCS) II drugs was conducted. A three-level two-factorial factorial design was carried out for the exploration of the influence of the pore size of MCF (X₁) and drug-loading degree (X₂) for drug release behaviors. Cumulative release in 1 h (Y₁), cumulative release in 24 h (Y₂), and rate constant k (Y₃) were selected as dependent response variables. A series of MCFs (7MCF, 12MCF, and 17MCF) with arithmetic increased pore diameters was synthesized as drug carriers. The morphologies and structures of MCFs and pore size distributions were detected by scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption analysis. With celecoxib as a model drug, nine drug-loaded samples were prepared and further characterized by differential scanning calorimetry and X-ray diffraction analyses. The release behavior was examined by in vitro dissolution. Factorial design results demonstrated that cumulative release in 1 h and the rate constant k were mainly affected by X₂, while cumulative release in 24 h was influenced by both X₁ and X₂. Furthermore, quadratic equations of Y₁, Y₂, and Y₃ were conducted, respectively. This work was expected to provide some scientific references for designing specific drug delivery models with mesoporous silica carrier.

Polyethylenimine-based nanocarriers in co-delivery of drug and gene: a developing horizon

The meaning of gene therapy is the delivery of DNA or RNA to cells for the treatment or prevention of genetic disorders. The success rate of gene therapy depends on the progression and safe gene delivery system. The vectors available for gene therapy are divided into viral and non-viral systems. Viral vectors cause higher transmission efficiency and long gene expression, but they have major problems, such as immunogenicity, carcinogenicity, the inability to transfer large size genes and high costs. Non-viral gene transfer vectors have attracted more attention because they exhibit less toxicity and the ability to transfer large size genes. However, the clinical application of non-viral methods still faces some limitations, including low transmission efficiency and poor gene expression. In recent years, numerous methods and gene-carriers have been developed to improve gene transfer efficiency. The use of Polyethylenimine (PEI) based transfer of collaboration may create a new way of treating diseases and the combination of chemotherapy and gene therapy. The purpose of this paper is to introduce the PEI as an appropriate vector for the effective gene delivery.