Search results for "Transfer technique"
showing 10 items of 87 documents
Tuning the pH-Switch of Supramolecular Polymer Carriers for siRNA to Physiologically Relevant pH
2017
The preparation of histidine enriched dendritic peptide amphiphiles and their self-assembly into multicomponent pH-switchable supramolecular polymers is reported. Alternating histidine and phenylalanine peptide synthons allow the assembly/disassembly to be adjusted in a physiologically relevant range of pH 5.3-6.0. Coassembly of monomers equipped with dendritic tetraethylene glycol chains with monomers bearing peripheral primary amine groups leads to nanorods with a tunable cationic surface charge density. These surface functional supramolecular polycations are able to reversibly bind short interfering RNA (siRNA). The nanorod-like supramolecular polymers, their complexation with siRNA, and…
Gene therapy for type 1 diabetes: is it ready for the clinic?
1999
This review, in addition to updating the growing list of type 1 diabetes- relevant gene therapies, offers an outline of short-term objectives that can readily be met to move, at least, adenoviral and adeno-associated viral-based protocols into the clinic, first as a means of facilitating islet allografts as well as platforms with which to introduce immunoregulatory transgenes. A wide array of genes have been tested to restore insulin production, to drive the differentiation of insulin-producing progenitors, and to confer immunosuppression in an antigen- and tissue-restricted manner.
Dendrimers as Non-Viral Vectors in Gene-Directed Enzyme Prodrug Therapy.
2021
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…
In silico characterization of the neural alpha tubulin gene promoter of the sea urchin embryo Paracentrotus lividus by phylogenetic footprinting
2011
During Paracentrotus lividus sea urchin embryo development one alpha and one beta tubulin genes are expressed specifically in the neural cells and they are early end output of the gene regulatory network that specifies the neural commitment. In this paper we have used a comparative genomics approach to identify con- served regulatory elements in the P. lividus neural alpha tubulin gene. To this purpose, we have first isolated a genomic clone containing the entire gene plus 4.5 Kb of 5 0 upstream sequences. Then, we have shown by gene transfer experiments that its non-coding region drives the spatio- temporal gene expression corresponding substantially to that of the endogenous gene. In addi…
Microwave-assisted synthesis of PHEA-oligoamine copolymers as potential gene delivery systems
2009
Aims - Copolymers bearing oligoamines and having buffering capacity in the endosomal pH range seems very promising as non viral vectors in gene delivery, due to the great importance of endosomal escaping for an efficient endocellular DNA release. Aim of this paper was to prepare new copolymers based on α,β-poly-(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) as polymeric backbone and bearing an oligoamine, such as diethylentriamine (DETA) in the side chain and useful for gene delivery. Moreover in order to reduce solvent volume and to make faster the reaction, microwave-assisted has been used. Materials and methods - PHEA copolymers bearing different amount of DETA were prepared by using bis(4-ni…
New pegylated polyaspartamide-based polyplexes as gene delivery vectors
2010
Aims: To synthesize novel polyhydroxyethylaspartamide (PHEA) copolymers containing spermine (Spm) and polyethylene glycol (PEG) moieties in high yields, with the expectation that this material would show stealth properties and the ability to complex DNA by electrostatic interactions. Materials & methods: PHEA–PEG–Spm copolymer was prepared with a two-step reaction. Chemical, physicochemical and biological characterizations of PHEA–PEG–Spm copolymers and their obtained polyplexes with pDNA were performed. Results: The introduction of spermine in PHEA structure allows to obtain a copolymer bearing in the side chains polyamine moieties capable to interact with DNA. On the other hand, the …
Lentivirus-induced dendritic cells for immunization against high-risk WT1(+) acute myeloid leukemia.
2013
Wilms' tumor 1 antigen (WT1) is overexpressed in acute myeloid leukemia (AML), a high-risk neoplasm warranting development of novel immunotherapeutic approaches. Unfortunately, clinical immunotherapeutic use of WT1 peptides against AML has been inconclusive. With the rationale of stimulating multiantigenic responses against WT1, we genetically programmed long-lasting dendritic cells capable of producing and processing endogenous WT1 epitopes. A tricistronic lentiviral vector co-expressing a truncated form of WT1 (lacking the DNA-binding domain), granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin-4 (IL-4) was used to transduce human monocytes ex vivo. Overnight transd…
Strong immunogenic potential of a B7 retroviral expression vector: generation of HLA-B7-restricted CTL response against selectable marker genes.
1998
The stimulation of a specific immune response is an attractive goal in cancer therapy. Gene transfer of co-stimulatory molecules and/or cytokine genes into tumor cells and the injection of these genetically modified cells leads to tumor rejection by syngeneic hosts and the induction of tumor immunity. However, the development of host immune response could be either due to the introduced immunomodulatory genes or due to vector components. In this study, human renal cell carcinoma cell lines were modified by a retrovirus to express the co-stimulatory molecule B7-1 together with the hygromycin/thymidine kinase fusion protein (HygTk) as positive and negative selection markers. These B7-1-transd…
DNA delivery to 'ex vivo' human liver segments.
2011
Hydrodynamic injection is an efficient procedure for liver gene therapy in rodents but with limited efficacy in large animals, using an 'in vivo' adapted regional hydrodynamic gene delivery system. We study the ability of this procedure to mediate gene delivery in human liver segments obtained by surgical resection. Watertight liver segments were retrogradely injected from hepatic vein with a saline solution containing a plasmid bearing the enhanced green fluorescent protein (eGFP) gene, under different conditions of flow rate (1, 10 and 20 ml s(-1)) and final perfused volume. Samples were cultured for 1 to 2 days and used for microscopy and molecular analysis of gene expression. The fluore…
A classification scheme for mobilization regions of bacterial plasmids
2003
Transmissible plasmids can be classified according to their mobilization ability, as being conjugative (self-transmissible) or mobilizable (transmissible only in the presence of additional conjugative functions). Naturally occurring mobilizable plasmids carry the genetic information necessary for relaxosome formation and processing, but lack the functions required for mating pair formation. Mobilizable plasmids have a tremendous impact in horizontal gene transfer in nature, including the spread of antibiotic resistance. However, analysis of their promiscuity and diversity has attracted less attention than that of conjugative plasmids. This review will focus on the analysis of the diversity …