Targeting the Retinoblastoma/E2F repressive complex by CDK4/6 inhibitors amplifies oncolytic potency of an oncolytic adenovirus.

CDK4/6 inhibitors (CDK4/6i) and oncolytic viruses are promising therapeutic agents for the treatment of various cancers. As single agents, CDK4/6 inhibitors that are approved for the treatment of breast cancer in combination with endocrine therapy cause G1 cell cycle arrest, whereas adenoviruses induce progression into S-phase in infected cells as an integral part of the their life cycle. Both CDK4/6 inhibitors and adenovirus replication target the Retinoblastoma protein albeit for different purposes.

Reduced Acquisition Time [F]GE-180 PET Scanning Protocol Replaces Gold-Standard Dynamic Acquisition in a Mouse Ischemic Stroke Model.

Aim: Understanding neuroinflammation after acute ischemic stroke is a crucial step on the way to an individualized post-stroke treatment. Microglia activation, an essential part of neuroinflammation, can be assessed using [F]GE-180 18 kDa translocator protein positron emission tomography (TSPO-PET). However, the commonly used 60-90 min post-injection (p.

Functional analysis of bioactivated and antiinfective PDLLA - coated surfaces.

Common scaffold surfaces such as titanium can have side effects; for example, infections, cytotoxicity, impaired osseointegration, or low regeneration rates for bone tissue. These effects lead to poor implant integration or even implant loss. Therefore, bioactive implants are promising instruments in tissue regeneration.

MagnetofectionTM platform: from magnetic nanoparticles to novel nucleic acid therapeutics.

Nucleic acid delivery to cells to make them produce a desired protein or to shut down the expression of endogenous genes opens unique possibilities for research and therapy. During the last decade, to realize the potential of this approach, nanomagnetic methods for delivering and targeting nucleic acids have been developed, methods which are often referred to as Magnetofection. Our research group at the Institute of Experimental Oncology and Therapy Research, located at the University Hospital Klinikum rechts der Isar in the center of Munich, Germany, develops new magnetic nanomaterials and, their formulations with gene-delivery vectors and technologies to allow localized and efficient gene delivery in vitro and in vivo for a variety of research, diagnostic and therapeutic applications.

A nebulized gelatin nanoparticle-based CpG formulation is effective in immunotherapy of allergic horses.

Purpose: In the recent years, nanotechnology has boosted the development of potential drug delivery systems and material engineering on nanoscale basis in order to increase drug specificity and reduce side effects. A potential delivery system for immunostimulating agents such as cytosine-phosphate-guanine-oligodeoxynucleotides (CpG-ODN) needs to be developed to maximize the efficacy of immunotherapy against hypersensitivity. In this study, an aerosol formulation of biodegradable, biocompatible and nontoxic gelatin nanoparticle-bound CpG-ODN 2216 was used to treat equine recurrent airway obstruction in a clinical study.

Effects of nanoparticle coatings on the activity of oncolytic adenovirus-magnetic nanoparticle complexes.

Limitations to adenovirus infectivity can be overcome by association with magnetic nanoparticles and enforced infection by magnetic field influence. Here we examined three core-shell-type iron oxide magnetic nanoparticles differing in their surface coatings, particle sizes and magnetic properties for their ability to enhance the oncolytic potency of adenovirus Ad520 and to stabilize it against the inhibitory effects of serum or a neutralizing antibody. It was found that the physicochemical properties of magnetic nanoparticles are critical determinants of the properties which govern the oncolytic productivities of their complexes with Ad520.

Immunostimulation of bronchoalveolar lavage cells from recurrent airway obstruction-affected horses by different CpG-classes bound to gelatin nanoparticles.

Recurrent airway obstruction (RAO) in horses has become a common problem in stabled horses in industrialized countries and deserves new therapeutic strategies. CpG-oligodeoxynucleotides (CpG-ODNs) were developed as effective immunostimulating agents to induce a Th2/Th1 shift. These agents showed a beneficial therapeutic effect in allergic diseases with predominant Th2 immunoresponse.

Successful anatomic repair of fetoscopic access sites in the mid-gestational rabbit model using amnion cell engineering.

Background/aim: Our aim was to evaluate the impact of in vitro cultured amnion cells, injected and/or seeded in different scaffolds, on in vivo fetal membrane repair.

Materials And Methods: Amnion cells, isolated from allogeneic fetal membranes, were cultured on three different scaffolds for 14 to 21 days. In 33 mid-gestational rabbits, fetoscopic access sites were randomly allocated to four closure study groups: conventional collagen plug, as well as collagen plug, collagen foil, and fibrin glue as scaffolds for the cultured amnion cells.

The influence of the stable expression of BMP2 in fibrin clots on the remodelling and repair of osteochondral defects.

Growth factors like BMP2 have been tested for osteochondral repair, but transfer methods used until now were insufficient. Therefore, the aim of this study was to analyse if stable BMP2 expression after retroviral vector (Bullet) transduction is able to regenerate osteochondral defects in rabbits. Fibrin clots colonized by control or BMP2-transduced chondrocytes were generated for in vitro experiments and implantation into standardized corresponding osteochondral defects (n=32) in the rabbit trochlea.

A fibrin glue composition as carrier for nucleic acid vectors.

Purpose: Gene delivery from biomaterials has become an important tool in tissue engineering. The purpose of this study was to generate a gene vector-doted fibrin glue as a versatile injectable implant to be used in gene therapy supported tissue regeneration.

Methods: Copolymer-protected polyethylenimine(PEI)-DNA vectors (COPROGs), naked DNA and PEI-DNA were formulated with the fibrinogen component of the fibrin glue TISSUCOL and lyophilized.

Neoadjuvant gene delivery of feline granulocyte-macrophage colony-stimulating factor using magnetofection for the treatment of feline fibrosarcomas: a phase I trial.

Despite aggressive pre- or postoperative treatment, feline fibrosarcomas have high recurrence rates. Immunostimulatory gene therapy is a promising approach in veterinary oncology. This phase I dose-escalation study was performed to determine toxicity and feasibility of gene therapy with feline granulocyte-macrophage colony-stimulating factor (feGM-CSF) in cats with fibrosarcomas.

Adjuvant immunotherapy of feline fibrosarcoma with recombinant feline interferon-omega.

Background: Recombinant feline interferon-omega (rFeIFN-omega) was tested as a treatment option for cats with fibrosarcoma to assess safety and feasibility.

Hypothesis: Treatment with rFeIFN-omega in cats with fibrosarcoma is safe and feasible.

Animals: Twenty domestic cats.

In vivo analysis of retroviral gene transfer to chondrocytes within collagen scaffolds for the treatment of osteochondral defects.

To examine a retroviral gene transfer to chondrocytes in vitro and in vivo in tissue-engineered cell-collagen constructs articular chondrocytes from rabbits and humans were isolated and transduced with VSV.G pseudotyped murine leukemia virus-derived retroviral vectors. Viral supernatants were generated by transient transfection of 293T cells using the pBullet retroviral vector carrying the nlslacZ gene, a Moloney murine leukemia virus gag/pol plasmid and a VSV.

Thyroid hormone (T3)-modification of polyethyleneglycol (PEG)-polyethyleneimine (PEI) graft copolymers for improved gene delivery to hepatocytes.

Targeting of gene vectors to liver hepatocytes could offer the opportunity to cure various acquired and inherited diseases. Efficient gene delivery to the liver parenchyma has been obscured from efficient targeting of hepatocytes. Here we show that the thyroid hormone, triiodothyronine (T3), can be used to improve the gene transfer efficiency of nonviral gene vectors to hepatocytes in vitro and to the liver of mice in vivo.

Aerosol gene delivery to the murine lung is mouse strain dependent.

The cationic polymer polyethylenimine (PEI) has been previously demonstrated to efficiently deliver genes to the lungs of mice in vivo via nebulization. Although within these studies various mouse strains were used in individual experiments, no direct comparison of gene delivery to different mouse strains via aerosol application has been published to date. With respect to the widespread use of mice as animal models of inherited and acquired diseases, such data could be of relevance to select the most appropriate mouse genetic background for preclinical mouse models.

Amnion cells engineering: a new perspective in fetal membrane healing after intrauterine surgery?

In this study we aimed to set up an in vitro culture of the rabbit amnion in order to support in vivo fetal membrane healing capacity following fetoscopy. Fetal membranes were collected from a mid-gestational rabbit, and cultured on collagen support material for 14 days. 34 rabbits at 22-23 days gestational age (GA) underwent fetoscopy.

Aerosolized nanogram quantities of plasmid DNA mediate highly efficient gene delivery to mouse airway epithelium.

The lung is an important target of gene therapeutic interventions. In contrast to intratracheal instillation, inhalation would be the most practical route of administration in clinical applications. Here we show that aerosolized nanogram quantities of pDNA complexed to PEI (350 ng) yielded transfection levels 15-fold higher than a 140-fold higher dose (50 microg) of the same vector applied directly to the lungs of mice via intratracheal intubation.

Application of novel solid lipid nanoparticle (SLN)-gene vector formulations based on a dimeric HIV-1 TAT-peptide in vitro and in vivo.

Purpose: To optimize gene delivery of SLN-based gene vectors by incorporation of a dimeric HIV-1 TAT peptide (TAT2) into SLN gene vectors.

Methods: Plasmid DNA was complexed with two SLN preparations either with or without pre-compaction of DNA by TAT2, poly-L-arginine, or the mutant TAT2-M1. DNA complexed with polyethylenimine (PEI) served as a standard.

Gene delivery to respiratory epithelial cells by magnetofection.

Background: For the topical application of DNA vector complexes to the airways, specific extracellular barriers play a major role. In particular, short contact time of complexes with the cell surface caused by the mucociliary clearance hinders cellular uptake of complexes. The aim of this study was to evaluate the ability of magnetofection, a technique based on the principle of magnetic drug targeting, to overcome these barriers in comparison with conventional nonviral gene transfer methods such as lipofection and polyfection.

The magnetofection method: using magnetic force to enhance gene delivery.

In order to enhance and target gene delivery we have previously established a novel method, termed magnetofection, which uses magnetic force acting on gene vectors that are associated with magnetic particles. Here we review the benefits, the mechanism and the potential of the method with regard to overcoming physical limitations to gene delivery. Magnetic particle chemistry and physics are discussed, followed by a detailed presentation of vector formulation and optimization work.

Oligomers of the arginine-rich motif of the HIV-1 TAT protein are capable of transferring plasmid DNA into cells.

We constructed multimers of the TAT-(47-57) peptide. This polycationic peptide is known to be a protein and particle transduction domain and at the same time to comprise a nuclear localization function. Here we show that oligomers of the TAT-(47-57) peptide compact plasmid DNA to nanometric particles and stabilize DNA toward nuclease degradation.

Nonviral vector loaded collagen sponges for sustained gene delivery in vitro and in vivo.

Background: Naked DNA and standard vectors have previously been used for gene delivery from implantable carrier matrices with great potential for gene therapeutic assistance of wound healing or tissue engineering. We have previously developed copolymer-protected gene vectors which are inert towards opsonization. Here we examine their potency in carrier-mediated gene delivery in comparison to standard vectors using a vector-loaded collagen sponge model.