Development of novel recombinant biomimetic chimeric MPG-based peptide as nanocarriers for gene delivery: Imitation of a real cargo

An Up-to-date Review on Protein-based Nanocarriers in the Management of Cancer

BACKGROUND

A big health issue facing the world's population is cancer. An alarming increase in cancer patients was anticipated by worldwide demographic statistics, which showed that the number of patients with different malignancies was rapidly increasing. By 2025, probably 420 million cases were projected to be achieved. The most common cancers diagnosed are breast, colorectal, prostate, and lung. Conventional treatments, such as surgery, chemotherapy, and radiation therapy, have been practiced.

OBJECTIVE

In recent years, the area of cancer therapy has changed dramatically with expanded studies on the molecular-level detection and treatment of cancer. Recent advances in cancer research have seen significant advances in therapies such as chemotherapy and immunotherapy, although both have limitations in effectiveness and toxicity.

METHODS

The development of nanotechnology for anticancer drug delivery has developed several potentials as nanocarriers, which may boost the pharmacokinetic and pharmacodynamic effects of the drug product and substantially reduce the side effects.

RESULTS

The advancement in non-viral to viral-based protein-based nanocarriers for treating cancer has earned further recognition in this respect. Many scientific breakthroughs have relied on protein-based nanocarriers, and proteins are essential organic macromolecules for life. It allows targeted delivery of passive or active tumors using non-viral-based protein-based nanocarriers to viral-based protein nanocarriers. When targeting cancer cells, both animal and plant proteins may be used in a formulation process to create self-assembled viruses and platforms that can successfully eradicate metastatic cancer cells.

CONCLUSION

This review, therefore, explores in depth the applications of non-viral to viral proteinbased noncarriers with a specific focus on intracellular drug delivery and anti-cancer drug targeting ability.

DNAi-peptide nanohybrid smart particles target BCL-2 oncogene and induce apoptosis in breast cancer cells

Genomic DNA sequences provide unique target sites, with high druggability value, for treatment of genetically-linked diseases like cancer. B-cell lymphoma protein-2 (BCL-2) prevents Bcl-2-associated X protein (BAX) and Bcl-2 antagonist killer 1 (BAK) oligomerization, which would otherwise lead to the release of several apoptogenic molecules from the mitochondrion. It is also known that BCL-2 binds to and inactivates BAX and other pro-apoptotic proteins, thereby inhibiting apoptosis. BCL-2 protein family, through its role in regulation of apoptotic pathways, is possibly related to chemo-resistance in almost half of all cancer types including breast cancer. Here for the first time, we have developed a nanohybrid using a peptide-based carrier and a Deoxyribonucleic acid inhibitor (DNAi) against BCL-2 oncogene to induce apoptosis in breast cancer cells. The genetically designed nanocarrier was functionalized with an internalizing RGD (iRGD) targeting motif and successfully produced by recombinant DNA technology. Gel retardation assay demonstrated that the peptide-based carrier binds single-stranded DNAi upon simple mixing. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) analyses further revealed the formation of nanohybrid particles with a size of 30 nm and a slightly positive charge. This hemocompatible nanohybrid efficiently delivered its contents into cancer cells using iRGD targeting moiety. Gene expression analysis demonstrated that the nanohybrids, which contained DNAi against BCL-2 proficiently suppressed the expression of this oncogene in a sequence specific manner. In addition, the nanohybrid, triggered release of cytochrome c (cyt c) and caspase3/7 activation with high efficiency. Although the DNAi and free nanocarrier were separately unable to affect the cell viability, the nanohybrid of 20 nM of DNAi showed outstanding antineoplastic potential, which was adjusted by the ratio of the MiRGD nanocarrier to DNAi. It should be noted that, the designed nanohybrid showed a suitable specificity profile and did not affect the viability of normal cells. The results suggest that this nanohybrid may be useful for robust breast cancer treatment through targeting the BCL-2 oncogene without any side effects.

In Vivo Hematopoietic Stem Cell Genome Editing: Perspectives and Limitations

The tremendous evolution of genome-editing tools in the last two decades has provided innovative and effective approaches for gene therapy of congenital and acquired diseases. Zinc-finger nucleases (ZFNs), transcription activator- like effector nucleases (TALENs) and CRISPR-Cas9 have been already applied by ex vivo hematopoietic stem cell (HSC) gene therapy in genetic diseases (i.e., Hemoglobinopathies, Fanconi anemia and hereditary Immunodeficiencies) as well as infectious diseases (i.e., HIV), and the recent development of CRISPR-Cas9-based systems using base and prime editors as well as epigenome editors has provided safer tools for gene therapy. The ex vivo approach for gene addition or editing of HSCs, however, is complex, invasive, technically challenging, costly and not free of toxicity. In vivo gene addition or editing promise to transform gene therapy from a highly sophisticated strategy to a "user-friendly' approach to eventually become a broadly available, highly accessible and potentially affordable treatment modality. In the present review article, based on the lessons gained by more than 3 decades of ex vivo HSC gene therapy, we discuss the concept, the tools, the progress made and the challenges to clinical translation of in vivo HSC gene editing.

An overview of polyallylamine applications in gene delivery

A chief objective of gene transportation studies is to manipulate clinically accepted carriers that can be utilized to combat incurable diseases. Despite various strategies, efficiency and application of these vectors have been hindered, owing to different obstacles. Polyallylamine (PAA) is a synthetic water-soluble, weak base cationic polymer with different properties that could be administrated as an ideal candidate for biomedical applications such as gene delivery, drug delivery, or even tissue engineering. However, some intrinsic properties of this polymer limit its application. The two associated problems with the use of PAA in gene delivery are low transfection efficiency (because of low buffering capacity) and cytotoxic effects attributed to intense cationic character. Most of the strategies for structural modification of the PAA structure have focused on introducing hydrophobic groups to the polymeric backbone that target both cytotoxicity and transfection. In this perspective, we concentrate on PAA as a gene delivery vehicle and the existing approaches for modification of this cationic polymer to give insight to researchers for exploitation of PAA as an efficient carrier in biomedical applications.

Design and preparation of a theranostic peptideticle for targeted cancer therapy: Peptide-based codelivery of doxorubicin/curcumin and graphene quantum dots

Although chemotherapy has been known as a powerful medication for cancer treatment over the years, there is an important necessity for designing a novel targeted drug delivery system to overcome the drawbacks of this conventional method including undesired side effects on normal cells and drug resistance. The structural differences between the surface of cancerous and normal cells allow to design and engineer targeted drug delivery systems for cancer treatment. Integrins as one of the cell surface receptors over-expressed in cancer cells could potentially be suitable candidates for targeting cancer cells. In the present study, the novel nano-carriers based on designed MiRGD peptides and graphene quantum dots (GQDs) have been used for targeted delivery of doxorubicin (Dox) and curcumin (Cur) as hydrophilic and hydrophobic drug models, respectively. The prepared nano-composites were characterized by UV-vis and photoluminescence (PL) spectroscopies, Zeta-Sizer and transmission electron microscopy (TEM). Altogether, the results of cellular uptake and fluorimetric assays performed in HUVEC and HFF cells as models of αv integrin-over-expressed cancer and normal cells, respectively, besides in-vivo study on breast cancer bearing BALB/c mice, demonstrated that the prepared nano-composites can be considered as suitable multifunctional theranostic peptideticles for targeted drug delivery and tracking.

Dendrimers as Non-Viral Vectors in Gene-Directed Enzyme Prodrug Therapy

Gene-directed enzyme prodrug therapy (GDEPT) has been intensively studied as a promising new strategy of prodrug delivery, with its main advantages being represented by an enhanced efficacy and a reduced off-target toxicity of the active drug. In recent years, numerous therapeutic systems based on GDEPT strategy have entered clinical trials. In order to deliver the desired gene at a specific site of action, this therapeutic approach uses vectors divided in two major categories, viral vectors and non-viral vectors, with the latter being represented by chemical delivery agents. There is considerable interest in the development of non-viral vectors due to their decreased immunogenicity, higher specificity, ease of synthesis and greater flexibility for subsequent modulations. Dendrimers used as delivery vehicles offer many advantages, such as: nanoscale size, precise molecular weight, increased solubility, high load capacity, high bioavailability and low immunogenicity. The aim of the present work was to provide a comprehensive overview of the recent advances regarding the use of dendrimers as non-viral carriers in the GDEPT therapy.

Self-assembly of an aptamer-decorated chimeric peptide nanocarrier for targeted cancer gene delivery

In this study, we developed a peptide-based non-viral carrier decorated with aptamer to overcome the specific gene delivery barriers. The carrier (KLN/Apt) was designed to contain multiple functional segments, including 1) two tandem repeating units of low molecular weight protamine (LMWP) to condense DNA into stable nanosize particles and protect it from enzymatic digestion, 2) AS1411 aptamer as targeting moiety to target nucleolin and promote carrier internalization, 3) a synthetic pH-sensitive fusogenic peptide (KALA) for disrupting endosomal membranes and enhancing cytosol escape of the nanoparticles, and 4) a nuclear localization signal (NLS) for active cytoplasmic trafficking and nuclear delivery of DNA. The obtained results revealed the developed carrier capacity in terms of specific cell targeting, overcoming cellular gene delivery barriers, and mediating efficient gene transfection. The KLN/pDNA/aptamer nanoparticles offer remarkable potential for the conceptual design and formation of promising multi-functionalized carriers towards the most demanding therapeutic applications.

Dramatic influence of the hydroxy functionality of azasugar moiety in the head group region of tocopherol-based cationic lipids on in vitro gene transfection efficacies

Cationic lipids have been effectively used as nonviral vectors for the delivery of polynucleic acids into the cytosol.

Ternary Nanocomplexes of Metallic Nanoclusters and Recombinant Peptides for Fluorescence Imaging and Enhanced Gene Delivery

The efficient carrier design for transferring therapeutic genes into target cells as well as tracking the delivered agents has attracted lots of attention in the field of DNA-based therapeutics. Here, we demonstrate this concept by a fast and facilitated method using BSA gold nanocluster (BSA AuNcs) conjugated with chimeric peptide with ability of DNA binding/packaging, endosome disruption and cell nuclear localization. An extensive characterization of photoluminescence properties, electrophoresis mobility and size distribution of the nanocarrier demonstrating the stable complexes composed of plasmid DNA, chimeric peptide and BSA AuNcs were successfully formed through electrostatic interactions. In the hybrid complexes, chimeric peptide could effectively decrease the cytotoxicity of AuNcs as well as enhance internalization of plasmid harboring firefly luciferase gene into HEK 293 T. The designed nanocarrier could be a promising vector in gene delivery systems for improved theranostics applications.

Design, Preparation, and Characterization of Peptide-Based Nanocarrier for Gene Delivery

The delivery of nucleic acid to eukaryotic cells is challenging due to presence of various intra- and extracellular barriers and need to delivery carriers. However, current gene delivery carriers, including PLL, PEI, and liposome, suffer from nanocarrier associate toxicity, low efficiency and polydispersity, and non-biodegradability. Here we describe our strategy for developing safe, efficacious, and monodisperse peptide-based carrier for gene delivery. We explain the use of genetic engineering technology for integrating various functional motifs in a single peptide, with less than 100 nm size, which facilitated gene delivery into mammalian cell.

Stepwise Development of Biomimetic Chimeric Peptides for Gene Delivery

Gene-based therapy largely relies on the vector type that allows a selective and efficient transfection into the target cells with maximum efficacy and minimal toxicity. Although, genes delivered utilizing modified viruses transfect efficiently and precisely, these vectors can cause severe immunological responses and are potentially carcinogenic. A promising method of overcoming this limitation is the use of non-viral vectors, including cationic lipids, polymers, dendrimers, and peptides, which offer potential routes for compacting DNA for targeted delivery. Although non-viral vectors exhibit reduced transfection efficiency compared to their viral counterpart, their superior biocompatibility, non-immunogenicity and potential for large-scale production make them increasingly attractive for modern therapy. There has been a great deal of interest in the development of biomimetic chimeric peptides. Biomimetic chimeric peptides contain different motifs for gene translocation into the nucleus of the desired cells. They have motifs for gene targeting into the desired cell, condense DNA into nanosize particles, translocate the gene into the nucleus and enhance the release of the particle into the cytoplasm. These carriers were developed in recent years. This review highlights the stepwise development of the biomimetic chimeric peptides currently being used in gene delivery.

Histone H2A-peptide-hybrided upconversion mesoporous silica nanoparticles for bortezomib/p53 delivery and apoptosis induction

The design and development of advanced gene/drug codelivery nanocarrier with good biocompatibility for cancer gene therapy is desirable. Herein, we reported a gene delivery nanoplatform to synergized bortezomib (BTZ) for cancer treatment with histone H2A-hybrided, upconversion luminescence (UCL)-guided mesoporous silica nanoparticles [UCNPs(BTZ)@mSiO₂-H2A]. The functionalization of H2A on the surface of UCNPs(BTZ)@mSiO₂ nanoparticles realized the improvement of biocompatibility and enhancement of gene encapsulation and transfection efficiency. More importantly, then UCNPs(BTZ)@mSiO₂-H2A/p53 induced specific and efficient apoptotic cell death in p53-null cancer cells and restored the functional activity of tumor suppressor p53 by the success of co-delivery of BTZ/p53. Moreover, the transfection with UCNPs(BTZ)@mSiO₂-H2A/p53 in p53-deficient non-small cell lung cancer cells changed the status of p53 and substantially enhanced the p53-mediated sensitivity of encapsulated BTZ inside the UCNPs(BTZ)@mSiO₂/p53. Meanwhile, core-shell structured mesoporous silica nanoparticles UCNPs@mSiO₂ as an UCL agent can detect the real-time interaction of nanoparticles with cells and uptake/penetration processes. The results here suggested that the as-developed UCNPs(BTZ)@mSiO₂-H2A/p53 nanoplatform with coordinating biocompatibility, UCL image, and sustained release manner might be desirable gene/drug codelivery nanocarrier for clinical cancer therapy.

Cholesterol-rich lipid-mediated nanoparticles boost of transfection efficiency, utilized for gene editing by CRISPR-Cas9

Purpose: Gene therapy has become a promising remedy to treat disease by modifying the person's genes. The therapeutic potential of related tools such as CRISPR-Cas9 depends on the efficiency of delivery to the targeted cells. Numerous transfection reagents have been designed and lots of efforts have been devoted to develop carriers for this purpose. Therefore, the aim of the present study was to develop novel cholesterol-rich lipid-based nanoparticles to enhance transfection efficiency and serum stability. Materials and methods: We constructed two-, three- and four-component cationic liposomes (CLs) to evaluate the combined effect of cholesterol domain and DOPE (dioleoyl phosphatidylethanolamine), a fusogenic lipid, and the PEG (polyethylene glycol) moiety location inside or outside of the cholesterol domain on transfection efficiency and other properties of the particle. Lipoplex formation and pDNA (plasmid DNA) entrapment were assessed by gel retardation assay at different N/P ratios (3, 5, 7). Physicochemical characteristics, cytotoxicity, serum stability and endosomal escape capability of the lipoplexes were studied and transfection potential was measured by firefly luciferase assay. Next, HEK293 cell line stably expressing GFP was utilized to demonstrate the editing of a reporter through Cas9 and sgRNA plasmids delivery by the selected CL formula, which showed the highest transfection efficiency. Results: Among the designed CLs, the four-component formula [DOTAP (1,2-dioleoyl-3-trimethylammoniumpropane)/DOPE/cholesterol/Chol-PEG (cholesterol-polyethylene glycol)] showed the highest rate of transfection at N/P 3. Finally, transfection of Cas9/sgRNA by this formulation at N/P 3 resulted in 39% gene-editing efficiency to knockout GFP reporter. The results also show that this CL with no cytotoxicity effect can totally protect the plasmids from enzymatic degradation in serum. Conclusion: The novel PEGylated cholesterol domain lipoplex providing serum stability, higher transfection efficiency and endosomal release can be used for in vivo Cas9/sgRNA delivery and other future gene-therapy applications.

Peptide-based gene delivery vectors

Gene therapy as a strategy for disease treatment requires safe and efficient gene delivery systems that encapsulate nucleic acids and deliver them to effective sites in the cell.

Gene Delivery to Tobacco Root Cells with Single-Walled Carbon Nanotubes and Cell-Penetrating Fusogenic Peptides

Development of efficient, easy, and safe gene delivery methods is of great interest in the field of plant biotechnology. Considering the limitations of the usual transfection methods (such as transgene size and plant type), several new techniques have been tested for replacement. The success of some biological and synthetic nanostructures such as cell-penetrating peptides and carbon nanotubes in transferring macromolecules (proteins and nucleic acids) into mammalian cells provoked us to assess the ability of an engineered chimeric peptide and also arginine functionalized single-walled carbon nanotube in gene delivery to intact tobacco (Nicotiana tabacum var. Virginia) root cells. It was suggested that the engineered peptide with its special cationic and hydrophobic domains and the arginine functionalized single-walled carbon nanotube due to its nano-cylindrical shape can pass plant cell barriers while plasmid DNA (which codes green fluorescent protein) has been condensed on them. The success of gene delivery to tobacco root cells was confirmed by fluorescence microscopy and western blotting analysis.

A comprehensive review on histone-mediated transfection for gene therapy

Histone has been considered to be an effective carrier in non-viral gene delivery due to its unique properties such as efficient DNA binding ability, direct translocation to cytoplasm and favorable nuclear localization ability. Meanwhile, the rapid development of genetic engineering techniques could facilitate the construction of multifunctional fusion proteins based on histone molecules to further improve the transfection efficiency. Remarkably, histone has been demonstrated to achieve gene transfection in a synergistic manner with cationic polymers, affording to a significant improvement of transfection efficiency. In the review, we highlighted the recent developments and future trends in gene delivery mediated by histones or histone-based fusion proteins/peptides. This review also discussed the mechanism of histone-mediated gene transfection and provided an outlook for future therapeutic opportunities in the viewpoint of transfection efficacy and biosafety.

ε-Poly-l-Lysine/plasmid DNA nanoplexes for efficient gene delivery in vivo

The present work addresses the development and characterization of ε-Poly-l-Lysine/pDNA polyplexes and evaluation for their improved transfection efficacy and safety as compared to polyplexes prepared using Poly-l-Lysine and SuperFect®. Self-assembling polyplexes were prepared by varying the N/P ratio to obtain the optimum size, a net positive zeta potential and gel retardation. The stability in presence of DNase I and serum was assured using gel retardation assay. Their appreciable uptake in MCF-7 and 3.5, 3.79 and 4.79-fold higher transfection compared to PLL/pDNA polyplexes and 1.60, 1.53 and 1.79-fold higher transfection compared to SuperFect®/pDNA polyplexes in MCF-7, HeLa and HEK-293 cell lines respectively, affirmed the enhanced transfection of ε-PLL/pDNA polyplexes which was well supported with in vivo transfection and gene expression studies. The <8% in vitro hemolysis and >98% viability of MCF-7, HeLa and HEK-293 cells in presence of ε-PLL/pDNA polyplexes addressed their safety, which was also ensured using in vivo toxicity studies, where hemocompatibility, unaltered levels of biochemical markers and histology of vital organs confirmed ε-PLL to be an effective and safer alternative for non-viral genetic vectors.

Non-viral gene delivery systems for tissue repair and regeneration

Critical tissue defects frequently result from trauma, burns, chronic wounds and/or surgery. The ideal treatment for such tissue loss is autografting, but donor sites are often limited. Tissue engineering (TE) is an inspiring alternative for tissue repair and regeneration (TRR). One of the current state-of-the-art methods for TRR is gene therapy. Non-viral gene delivery systems (nVGDS) have great potential for TE and have several advantages over viral delivery including lower immunogenicity and toxicity, better cell specificity, better modifiability, and higher productivity. However, there is no ideal nVGDS for TRR, hence, there is widespread research to improve their properties. This review introduces the basic principles and key aspects of commonly-used nVGDSs. We focus on recent advances in their applications, current challenges, and future directions.

Simultaneous Gene Delivery and Tracking through Preparation of Photo-Luminescent Nanoparticles Based on Graphene Quantum Dots and Chimeric Peptides

Designing suitable nano-carriers for simultaneous gene delivery and tracking is in the research priorities of the molecular medicine. Non-toxic graphene quantum dots (GQDs) with two different (green and red) emission colors are synthesized by Hummer's method and characterized by UV-Vis, Photoluminescence (PL), Fourier Transform Infrared (FTIR) and Raman spectroscopies, Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The GQDs are conjugated with MPG-2H1 chimeric peptide and plasmid DNA (pDNA) by non-covalent interactions. Following conjugation, the average diameter of the prepared GQDs increased from 80 nm to 280 nm in complex structure, and the ζ-potential of the complex increased (from -36.87 to -2.56 mV). High transfection efficiency of the nano-carrier and results of confocal microscopy demonstrated that our construct can be considered as a nontoxic carrier with dual functions for gene delivery and nuclear targeting.

Peptides, polypeptides and peptide–polymer hybrids as nucleic acid carriers

Peptide, polypeptide and polymer–peptide hybrid based nucleic acid therapeutics (NAT).