Amino Acid-Linked Low Molecular Weight Polyethylenimine for Improved Gene Delivery and Biocompatibility

Gallic Acid-Modified Polyethylenimine-Polypropylene Carbonate-Polyethylenimine Nanoparticles: Synthesis, Characterization, and Anti-Periodontitis Evaluation

The aim of the research was to develop novel gallic acid (GA)-modified amphiphilic nanoparticles of polyethylenimine (PEI)-polypropylene carbonate (PPC)-PEI (PEPE) and comprehensively assess its properties as an antiperiodontitis nanoparticle targeting the Toll-like receptor (TLR). The first step is to evaluate the binding potential of GA to the core trigger receptors TLR2 and TLR4/MD2 for periodontitis using molecular docking techniques. Following this, we conducted NMR, transmission electron microscopy, and dynamic light scattering analyses on the synthesized PEPE nanoparticles. As the final step, we investigated the synthetic results and in vitro antiperiodontitis properties of GA-PEPE nanoparticles. The investigation revealed that GA exhibits potential for targeted binding to TLR2 and the TLR4/MD2 complex. Furthermore, we successfully developed 91.19 nm positively charged PEPE nanoparticles. Spectroscopic analysis indicated the successful synthesis of GA-modified PEPE. Additionally, CCK8 results demonstrated that GA modification significantly reduced the biotoxicity of PEPE. The in vitro antiperiodontitis properties assessment illustrated that 6.25 μM of GA-PEPE nanoparticles significantly reduced the expression of pro-inflammatory factors TNF-α, IL-1β, and IL-6. The GA-PEPE nanoparticles, with their targeted TLR binding capabilities, were found to possess excellent biocompatibility and antiperiodontitis properties. GA-PEPE nanoparticles will provide highly innovative input into the development of anti- periodontitis nanoparticles.

Polyethylenimine (PEI) in gene therapy: Current status and clinical applications

Polyethlyenimine (PEI) was introduced 1995 as a cationic polymer for nucleic acid delivery. PEI and its derivatives are extensively used in basic research and as reference formulations in the field of polymer-based gene delivery. Despite its widespread use, the number of clinical applications to date is limited. Thus, this review aims to consolidate the past applications of PEI in DNA delivery, elucidate the obstacles that hinder its transition to clinical use, and highlight potential prospects for novel iterations of PEI derivatives. The present review article is divided into three sections. The first section examines the mechanism of action employed by PEI, examining fundamental aspects of cellular delivery including uptake mechanisms, release from endosomes, and transport into the cell nucleus, along with potential strategies for enhancing these delivery phases. Moreover, an in-depth analysis is conducted concerning the mechanism underlying cellular toxicity, accompanied with approaches to overcome this major challenge. The second part is devoted to the in vivo performance of PEI and its application in various therapeutic indications. While systemic administration has proven to be challenging, alternative localized delivery routes hold promise, such as treatment of solid tumors, application as a vaccine, or serving as a therapeutic agent for pulmonary delivery. In the last section, the outcome of completed and ongoing clinical trials is summarized. Finally, an expert opinion is provided on the potential of PEI and its future applications. PEI-based formulations for nucleic acid delivery have a promising potential, it will be an important task for the years to come to introduce innovations that address PEI-associated shortcomings by introducing well-designed PEI formulations in combination with an appropriate route of administration.

The use of RNA-based treatments in the field of cancer immunotherapy

Over the past several decades, mRNA vaccines have evolved from a theoretical concept to a clinical reality. These vaccines offer several advantages over traditional vaccine techniques, including their high potency, rapid development, low-cost manufacturing, and safe administration. However, until recently, concerns over the instability and inefficient distribution of mRNA in vivo have limited their utility. Fortunately, recent technological advancements have mostly resolved these concerns, resulting in the development of numerous mRNA vaccination platforms for infectious diseases and various types of cancer. These platforms have shown promising outcomes in both animal models and humans. This study highlights the potential of mRNA vaccines as a promising alternative approach to conventional vaccine techniques and cancer treatment. This review article aims to provide a thorough and detailed examination of mRNA vaccines, including their mechanisms of action and potential applications in cancer immunotherapy. Additionally, the article will analyze the current state of mRNA vaccine technology and highlight future directions for the development and implementation of this promising vaccine platform as a mainstream therapeutic option. The review will also discuss potential challenges and limitations of mRNA vaccines, such as their stability and in vivo distribution, and suggest ways to overcome these issues. By providing a comprehensive overview and critical analysis of mRNA vaccines, this review aims to contribute to the advancement of this innovative approach to cancer treatment.

Preparation of an amphiphilic peptide (P13) with proton sponge effect and analysis of its antitumor activity

In order to prevent drugs from being captured and degraded by the acidic environment of organelles, such as lysosomes, after entering cells, this study designed and synthesized a novel carrier amphiphilic polypeptide (DGRHHHLLLAAAA), designated P13, for use as a tumor-targeting drug delivery vehicle. The P13 peptide was synthesized by the solid phase synthesis method, and its self-assembly behavior and drug-loading capacity in aqueous solution were studied and characterizedin vitro. Doxorubicin (DOX) was loaded by dialysis method, and P13 and DOX were mixed at a mass ratio of 6:1 to form regular rounded globules. The acid-base buffering capacity of P13 was investigated determined by acid-base titration. The results revealed that P13 had excellent acid-base buffering capacity, a critical micelle concentration value of about 0.000 21 g l^-1, and the particle size of P13-Dox nanospheres was 167 nm. The drug encapsulation efficiency and drug loading capacity of micelles were 20.40 ± 1.21% and 21.25 ± 2.79%, respectively. At the concentration of 50μg ml^-1of P13-DOX , the inhibition rate was 73.35%. The results of thein vivoantitumor activity assay in mice showed that P13-DOX also exhibited excellent inhibitory effect on tumor growth, compared with the tumor weight of 1.1 g in the control group, the tumor weight in the P13-DOX-treated group was only 0.26 g. Additionally, the results of hematoxylin and eosin staining of the organs showed that P13-DOX had no damaging effect on normal tissues. The novel amphiphilic peptide P13 with proton sponge effect designed and prepared in this study is expected to be a promising tumor-targeting drug carrier with excellent application potential.

Recent advances in nanotechnology approaches for non-viral gene therapy

Gene therapy has shown great potential in the treatment of many diseases by downregulating the expression of certain genes. The development of gene vectors as a vehicle for gene therapy has greatly facilitated the widespread clinical application of nucleic acid materials (DNA, mRNA, siRNA, and miRNA). Currently, both viral and non-viral vectors are used as delivery systems of nucleic acid materials for gene therapy. However, viral vector-based gene therapy has several limitations, including immunogenicity and carcinogenesis caused by the exogenous viral vectors. To address these issues, non-viral nanocarrier-based gene therapy has been explored for superior performance with enhanced gene stability, high treatment efficiency, improved tumor-targeting, and better biocompatibility. In this review, we discuss various non-viral vector-mediated gene therapy approaches using multifunctional biodegradable or non-biodegradable nanocarriers, including polymer-based nanoparticles, lipid-based nanoparticles, carbon nanotubes, gold nanoparticles (AuNPs), quantum dots (QDs), silica nanoparticles, metal-based nanoparticles and two-dimensional nanocarriers. Various strategies to construct non-viral nanocarriers based on their delivery efficiency of targeted genes will be introduced. Subsequently, we discuss the cellular uptake pathways of non-viral nanocarriers. In addition, multifunctional gene therapy based on non-viral nanocarriers is summarized, in which the gene therapy can be combined with other treatments, such as photothermal therapy (PTT), photodynamic therapy (PDT), immunotherapy and chemotherapy. We also provide a comprehensive discussion of the biological toxicity and safety of non-viral vector-based gene therapy. Finally, the present limitations and challenges of non-viral nanocarriers for gene therapy in future clinical research are discussed, to promote wider clinical applications of non-viral vector-based gene therapy.

Solid-Phase Synthesized Copolymers for the Assembly of pH-Sensitive Micelles Suitable for Drug Delivery Applications

Diblock copolymers of polyhistidine are known for their self-assembly into micelles and their pH-dependent disassembly due to the amphiphilic character of the copolymer and the unsaturated imidazole groups that undergo a hydrophobic-to-hydrophilic transition in an acidic pH. This property has been largely utilized for the design of drug delivery systems that target a tumor environment possessing a slightly lower extracellular pH (6.8–7.2). The main purpose of this study was to investigate the possibility of designed poly(ethylene glycol)-polyhistidine sequences synthesized using solid-phase peptide synthesis (SPPS), to self-assemble into micelles, to assess the ability of the corresponding micelles to be loaded with doxorubicin (DOX), and to investigate the drug release profile at pH values similar to a malignant extracellular environment. The designed and assembled free and DOX-loaded micelles were characterized from a physico-chemical point of view, their cytotoxicity was evaluated on a human breast cancer cell line (MDA-MB-231), while the cellular areas where micelles disassembled and released DOX were assessed using immunofluorescence. We concluded that the utilization of SPPS for the synthesis of the polyhistidine diblock copolymers yielded sequences that behaved similarly to the copolymeric sequences synthesized using ring-opening polymerization, while the advantages of SPPS may offer facile tuning of the histidine site or the attachment of a large variety of functional molecules.

Polyethylenimine-Modified Bombyx mori Silk Fibroin as a Delivery Carrier of the ING4-IL-24 Coexpression Plasmid

One of the major challenges for lung cancer gene therapy is to find a gene delivery vector with high efficiency and low toxicity. In this study, low-molecular-weight polyethyleneimine (PEI, 1.8 kDa) was grafted onto the side chains of Bombyx mori silk fibroin (BSF) to prepare cationized BSF (CBSF), which was used to package the plasmid DNA (pDNA) encoded by the inhibitor of growth 4 (ING4) and interleukin-24 (IL-24). FTIR and 1H-NMR spectra demonstrated that PEI was effectively coupled to the side chains of BSF by amino bonds. The results of the trinitrobenzene sulfonic acid method and zeta potential showed that the free amino group content on BSF increased from 125.1 ± 1.2 µmol/mL to 153.5 ± 2.2 µmol/mL, the isoelectric point increased from 3.68 to 8.82, and the zeta potential reversed from - 11.8 ± 0.1 mV to + 12.4 ± 0.3 mV after PEI grafting. Positively charged CBSF could package pDNA to form spherical CBSF/pDNA complexes. In vitro, human lung adenocarcinoma A549 cells and human embryonic lung fibroblast WI-38 cells were transfected with CBSF/pDNA complexes. Confocal laser scanning microscopy analysis and flow cytometry tests showed that CBSF/pDNA complexes can effectively transfect A549 cells, and the transfection efficiency was higher than that of 25 kDa PEI/pDNA complexes. CCK-8 assay results showed that CBSF/pDNA complexes significantly inhibited the proliferation of A549 cells but had no significant effect on WI-38 cells and exhibited lower cytotoxicity to WI-38 cells than 25 kDa PEI. Therefore, a gene delivery system, constructed with the low-molecular-weight PEI-modified silk fibroin protein and the ING4-IL-24 double gene coexpression plasmid has potential applications in gene therapy for lung cancer.

Lipoic Acid-Modified Oligoethyleneimine-Mediated miR-34a Delivery to Achieve the Anti-Tumor Efficacy

MiR-34a, an important tumor suppressor, has been demonstrated to possess great potential in tumor gene therapy. To achieve the upregulation of miR-34a expression level, an oligoethyleneimine (OEI) derivative was constructed and employed as the carrier through the modification with lipoic acid (LA), namely LA-OEI. In contrast to OEI, the derivative LA-OEI exhibited superior transfection efficiency measured by confocal laser scanning microscopy and flow cytometry, owing to rapid cargo release in the disulfide bond-based reduction sensitive pattern. The anti-proliferation and anti-migration effects were tested after the miR-34a transfection to evaluate the anti-tumor response, using human cervical carcinoma cell line HeLa as a model. The delivery of LA-OEI/miR-34a nanoparticles could achieve obvious anti-proliferative effect caused by the induction of cell apoptosis and cell cycle arrest at G1 phase. In addition, it could inhibit the migration of tumor cells via the downregulation of MMP-9 and Notch-1 level. Overall, the LA-OEI-mediated miR-34a delivery was potential to be used as an effective way in the tumor gene therapy.

A review of the tortuous path of nonviral gene delivery and recent progress

Gene therapy encompasses the transfer of exogenous genetic materials into the patient's target cells to treat or prevent diseases. Nevertheless, the transfer of genetic material into desired cells is challenging and often requires specialized tools or delivery systems. For the past 40 years, scientists are mainly pursuing various viruses as gene delivery vectors, and the overall progress has been slow and far from the expectation. As an alternative, nonviral vectors have gained substantial attention due to their several advantages, including superior safety profile, enhanced payload capacity, and stealth abilities. Since nonviral vectors encounter multiple extra- and intra-cellular barriers limiting the transfer of genetic payload into the target cell nucleus, we have discussed these barriers in detail for this review. A direct approach, utilizing physical methods like electroporation, sonoporation, gene gun, eliminate the requirement for a specific carrier for gene delivery. In contrast, chemical methods of gene transfer exploit natural or synthetic compounds as carriers to increase cellular targeting and gene therapy effectiveness. We have also emphasized the recent advancements aimed at enhancing the current nonviral approaches. Therefore, in this review, we have focused on discussing the current evolving state of nonviral gene delivery systems and their future perspectives.

Self-Assembled Biodegradable Core-Shell Nanocomposites of Amphiphilic Retinoic Acid-LMW bPEI Conjugates Exhibit Enhanced Transgene Expression in Hepatocellular Carcinoma Cells With Inherent Anticancer Properties

Low molecular weight branched polyethylenimines (LMW bPEIs) are almost nontoxic but display poor transfection efficiency due to lack of adequate complexation ability with nucleic acids followed by transportation across the cell membrane. Here, a series of amphiphilic retinoyl-bPEI conjugates (RP-1, RP-2 and RP-3) has been synthesized by allowing the reaction between bPEI (1.8 kDa) and a bioactive and hydrophobic vitamin A metabolite, all-trans-retinoic acid (ATRA), in varying amounts. In aqueous medium, these conjugates self-assembled into core-shell RP nanocomposites with size ranging from ~113-178 nm and zeta potential from ~ +15-35 mV. Evaluation of pDNA complexes of RP nanocomposites revealed that all the complexes exhibited significantly enhanced transfection efficiency without compromising on the cytocompatibility. RP-3/pDNA complex, with the highest content of retinoic acid, exhibited the best transfection efficiency. Further, due to anticancer properties of ATRA, these nanocomposites significantly reduced the viability of cancer cells (HepG2 and MCF-7 cells) without affecting the viability of non-cancerous cells (HEK 293 cells) demonstrating the cell-selective nature of the formulated nanocomposites. The intracellular trafficking and co-localization studies involving RP-3 nanocomposites also showed their higher uptake with intracellular and nuclear accumulation properties. Altogether, the results demonstrate the promising potential of the RP conjugates that can be used in future hepatocellular carcinoma targeted gene delivery applications.