scholarly journals Nanotherapeutics Shielded With a pH Responsive Polymeric Layer

2015 ◽  
pp. S29-S44 ◽  
Author(s):  
L. KOSTKA ◽  
V. ŠUBR ◽  
R. LAGA ◽  
P. CHYTIL ◽  
K. ULBRICH ◽  
...  

Efficient intravenous delivery is the greatest single hurdle, with most nanotherapeutics frequently found to be unstable in the harsh conditions of the bloodstream. In the case of nanotherapeutics for gene delivery, viral vectors are often avidly recognized by both the innate and the adaptive immune systems. So, most modern delivery systems have benefited from being coated with hydrophilic polymers. Self-assembling delivery systems can achieve both steric and lateral stabilization following surface coating, endowing them with much improved systemic circulation properties and better access to disseminated targets; similarly, gene delivery viral vectors can be ‘stealthed’ and their physical properties modulated by surface coating. Polymers that start degrading under acidic conditions are increasingly investigated as a pathway to trigger the release of drugs or genes once the carrier reaches a slightly acidic tumor environment or after the carrier has been taken up by cells, resulting in the localization of the polymer in acidic endosomes and lysosomes. Advances in the design of acid-degradable drug and gene delivery systems have been focused and discussed in this article with stress placed on HPMA-based copolymers. We designed a system that is able to “throw away” the polymer coat after successful transport of the vector into a target cell. Initial biological studies were performed and it was demonstrated that this principle is applicable for real adenoviral vectors. It was shown that the transfection ability of coated virus at pH 7.4 is 75 times lower then transfection at pH 5.4.

1999 ◽  
Vol 380 (6) ◽  
Author(s):  
H. Büeler

AbstractAdeno-associated virus (AAV) is a defective, non-pathogenic human parvovirus that depends for growth on coinfection with a helper adenovirus or herpes virus. Recombinant adeno-associated viruses (rAAVs) have attracted considerable interest as vectors for gene therapy. In contrast to other gene delivery systems, rAAVs lack all viral genes and show long-term gene expression


Nano LIFE ◽  
2010 ◽  
Vol 01 (03n04) ◽  
pp. 219-237 ◽  
Author(s):  
SHARDOOL JAIN ◽  
HUSAIN ATTARWALA ◽  
MANSOOR AMIJI

Gene therapy holds tremendous promise in prevention and treatment of diseases as the approach is based on regulating the expression of genes that are responsible for pathological conditions. The biggest bottleneck for gene delivery has been the development of safe and efficacious delivery systems. Although non-viral vectors are considered as much safer options than their viral counterparts, they suffer from low transfection efficiency. In this review, we highlight the role of non-condensing polymeric delivery systems for oral and systemic gene delivery. Using evidence from contemporary literature, non-condensing polymeric microparticle and nanoparticle systems afford physical encapsulation of the nucleic acid construct and can be engineered for targeted delivery to tissues and cells. Additionally, these systems have shown less toxicity and afford sustained cytoplasmic DNA delivery for efficient nuclear uptake and transfection for both DNA vaccines and therapeutic genes.


2019 ◽  
Vol 2 (1) ◽  
pp. 6-13 ◽  
Author(s):  
Kiel Sung Yong ◽  
◽  
Wan Kim Sung ◽  
◽  
◽  
...  

Gene therapy is the unique method for the use of genetic materials such as Messenger ribonucleic acid (mRNA), plasmid deoxyribonucleic acid (pDNA), and small interfering ribonucleic acid (siRNA) into specific host-cells for the treatment of inherited disorders in any diseases. The successful way to utilize the gene therapy is to develop the efficient cancer gene delivery systems. In this paper, the successful and efficient gene delivery systems are briefly reviewed on the basis of bio-reducible polymeric systems for cancer therapy. The viral gene delivery systems such as RNA-based viral and DNA-based viral vectors are also discussed. The development of bio-reducible polymer for gene delivery system has briefly discussed for the efficient cancer gene delivery of viral vectors and non-viral vectors.


2021 ◽  
Author(s):  
Hongyi Li ◽  
John E Heath ◽  
James S Trippett ◽  
Mikhail G. Shapiro ◽  
Jerzy O Szablowski

Targeted gene delivery to the brain is a critical tool for neuroscience research and has significant potential to treat human disease. However, the site-specific delivery of common gene vectors such as adeno-associated viruses (AAVs) is typically performed via invasive injections, limiting their scope of research and clinical applications. Alternatively, focused ultrasound blood-brain-barrier opening (FUS-BBBO), performed noninvasively, enables the site-specific entry of AAVs into the brain from systemic circulation. However, when used in conjunction with natural AAV serotypes, this approach has limited transduction efficiency, requires ultrasound parameters close to tissue damage limits, and results in undesirable transduction of peripheral organs. Here, we use high throughput in vivo selection to engineer new AAV vectors specifically designed for local neuronal transduction at the site of FUS-BBBO. The resulting vectors substantially enhance ultrasound-targeted gene delivery and neuronal tropism while reducing peripheral transduction, providing a more than ten-fold improvement in targeting specificity. In addition to enhancing the only known approach to noninvasively target gene delivery to specific brain regions, these results establish the ability of AAV vectors to be evolved for specific physical delivery mechanisms.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Kitae Ryu ◽  
Gyeong Jin Lee ◽  
Ji-yeong Choi ◽  
Taewan Kim ◽  
Tae-il Kim

Self-assembling multifunctional peptide was designed for gene delivery systems. The multifunctional peptide (MP) consists of cellular penetrating peptide moiety (R8), matrix metalloproteinase-2 (MMP-2) specific sequence (GPLGV), pH-responsive moiety (H5), and hydrophobic moiety (palmitic acid) (CR8GPLGVH5-Pal). MP was oxidized to form multifunctional peptide dimer (MPD) by DMSO oxidation of thiols in terminal cysteine residues. MPD could condense pDNA successfully at a weight ratio of 5. MPD itself could self-assemble into submicron micelle particles via hydrophobic interaction, of which critical micelle concentration is about 0.01 mM. MPD showed concentration-dependent but low cytotoxicity in comparison with PEI25k. MPD polyplexes showed low transfection efficiency in HEK293 cells expressing low level of MMP-2 but high transfection efficiency in A549 and C2C12 cells expressing high level of MMP-2, meaning the enhanced transfection efficiency probably due to MMP-induced structural change of polyplexes. Bafilomycin A1-treated transfection results suggest that the transfection of MPD is mediated via endosomal escape by endosome buffering ability. These results show the potential of MPD for MMP-2 targeted gene delivery systems due to its multifunctionality.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 793
Author(s):  
J.F.A. Valente ◽  
P. Pereira ◽  
A. Sousa ◽  
J.A. Queiroz ◽  
F. Sousa

Gene therapy could be simply defined as a strategy for the introduction of a functional copy of desired genes in patients, to correct some specific mutation and potentially treat the respective disorder. However, this straightforward definition hides very complex processes related to the design and preparation of the therapeutic genes, as well as the development of suitable gene delivery systems. Within non-viral vectors, polymeric nanocarriers have offered an ideal platform to be applied as gene delivery systems. Concerning this, the main goal of the study was to do a systematic evaluation on the formulation of pDNA delivery systems based on the complexation of different sized plasmids with chitosan (CH) or polyethyleneimine (PEI) polymers to search for the best option regarding encapsulation efficiency, surface charge, size, and delivery ability. The cytotoxicity and the transfection efficiency of these systems were accessed and, for the best p53 encoding pDNA nanosystems, the ability to promote protein expression was also evaluated. Overall, it was showed that CH polyplexes are more efficient on transfection when compared with the PEI polyplexes, resulting in higher P53 protein expression. Cells transfected with CH/p53-pDNA polyplexes presented an increase of around 54.2% on P53 expression, while the transfection with the PEI/p53-pDNA polyplexes resulted in a 32% increase.


2019 ◽  
Vol 16 (7) ◽  
pp. 588-608 ◽  
Author(s):  
Anjuman A. Begum ◽  
Istvan Toth ◽  
Waleed M. Hussein ◽  
Peter M. Moyle

Gene therapy has the potential to treat both acquired and inherited genetic diseases. Generally, two types of gene delivery vectors are used - viral vectors and non-viral vectors. Non-viral gene delivery systems have attracted significant interest (e.g. 115 gene therapies approved for clinical trials in 2018; clinicaltrials.gov) due to their lower toxicity, lack of immunogenicity and ease of production compared to viral vectors. To achieve the goal of maximal therapeutic efficacy with minimal adverse effects, the cell-specific targeting of non-viral gene delivery systems has attracted research interest. Targeting through cell surface receptors; the enhanced permeability and retention effect, or pH differences are potential means to target genes to specific organs, tissues, or cells. As for targeting moieties, receptorspecific ligand peptides, antibodies, aptamers and affibodies have been incorporated into synthetic nonviral gene delivery vectors to fulfill the requirement of active targeting. This review provides an overview of different potential targets and targeting moieties to target specific gene delivery systems.


2010 ◽  
Vol 13 (3) ◽  
pp. 472 ◽  
Author(s):  
Crispin Dass ◽  
Somayeh Hallaj-Nezhadi ◽  
Farzaneh Lotfipour

Interleukin-12 (Il-12) is a heterodimeric cytokine which has been proved to possess antitumor effects in various animal models via stimulating the immune system. The main problem associated with Il-12 protein delivery is its instability as well as cytotoxicity subsequent to systemic administration in rodents and in human clinical trials. However, gene delivery can be used to deliver genes of interest to the tumor site. Hence, a large number of studies have been undertaken to deliver genes of interest to the tumor site through viral or non-viral vectors. Viral DNA delivery systems suffer from safety concern due to the toxicity of the viruses and strong immune response; while non-viral gene delivery systems proffer lower transfection efficiency. Nevertheless, nanometer-size complex of therapeutic DNA may demonstrate more efficient for administration of therapeutic genes to solid tumors compared to administration of naked plasmid DNA. Nanoparticle-based gene delivery systems might be more pertinent, due to the enhanced tissue penetrability, improved cellular uptake. Il-12 gene delivery has already been reported with different nanoparticles containing DNA. This article provides a review on the in vivo and in vitro studies using various nanoparticles, for delivery of the Il-12 genes to neoplastic cells. The future of these promising approaches lies in the development of better techniques for preparing il-12 gene delivery systems with complete efficiency of viral vectors in addition to the highest safety for cancer patients.


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