Takotsubo cardiomyopathy in a 12-year-old boy caused by acute brainstem bleeding-a case report.

Takotsubo cardiomyopathy is characterized by acute and reversible severe left ventricular dysfunction due to intensive emotional or physical stress followed by catecholamine excess. Traditionally it is most common in postmenopausal women, whereas only few cases have been described in childhood. In our case a previously well 12-year-old boy presented with severe cardiogenic shock due to dramatically impaired left ventricular function requiring significant inotropic support and invasive mechanical ventilation. Interestingly, cardiac catheterization, myocardial tissue histology and biochemical laboratory tests did not yield a definitive diagnosis. As his cardiac function improved gradually within several days and deep sedation could be weaned, he was then found to suffer from hemiparesis and absence of protective airway reflexes on neurological examination during the weaning process. Subsequent brain imaging studies revealed a brainstem bleeding due to a fistulous arteriovenous malformation (AVM) appearing to be only a few days old. After endovascular coiling and subsequent microsurgical resection of the malformation, he recovered completely. Our present case demonstrated, that brainstem bleeding could precipitate Takotsubo cardiomyopathy manifesting hemodynamic collapse. Severe ventricular impairment has been described in many adults with subarachnoid hemorrhage; however, this condition is extremely rare among children. When severe cardiogenic shock is diagnosed, precipitating factors such as intracranial processes should be ruled out on a regular basis.

Self-assembled peptide-poloxamine nanoparticles enable in vitro and in vivo genome restoration for cystic fibrosis.

Developing safe and efficient non-viral delivery systems remains a major challenge for in vivo applications of gene therapy, especially in cystic fibrosis. Unlike conventional cationic polymers or lipids, the emerging poloxamine-based copolymers display promising in vivo gene delivery capabilities. However, poloxamines are invalid for in vitro applications and their in vivo transfection efficiency is still low compared with viral vectors. Here, we show that peptides developed by modular design approaches can spontaneously form compact and monodisperse nanoparticles with poloxamines and nucleic acids via self-assembly. Both messenger RNA and plasmid DNA expression mediated by peptide-poloxamine nanoparticles are greatly boosted in vitro and in the lungs of cystic fibrosis mice with negligible toxicity. Peptide-poloxamine nanoparticles containing integrating vectors enable successful in vitro and in vivo long-term restoration of cystic fibrosis transmembrane conductance regulator deficiency with a safe integration profile. Our dataset provides a new framework for designing non-viral gene delivery systems qualified for in vivo genetic modifications.

Nebulisation of IVT mRNA Complexes for Intrapulmonary Administration.

During the last years the potential role of in vitro transcribed (IVT) mRNA as a vehicle to deliver genetic information has come into focus. IVT mRNA could be used for anti-cancer therapies, vaccination purposes, generation of pluripotent stem cells and also for genome engineering or protein replacement. However, the administration of IVT mRNA into the target organ is still challenging. The lung with its large surface area is not only of interest for delivery of genetic information for treatment of e.g. for cystic fibrosis or alpha-1-antitrypsin deficiency, but also for vaccination purposes. Administration of IVT mRNA to the lung can be performed by direct intratracheal instillation or by aerosol inhalation/nebulisation. The latter approach shows a non-invasive tool, although it is not known, if IVT mRNA is resistant during the process of nebulisation. Therefore, we investigated the transfection efficiency of non-nebulised and nebulised IVT mRNA polyplexes and lipoplexes in human bronchial epithelial cells (16HBE). A slight reduction in transfection efficiency was observed for lipoplexes (Lipofectamine 2000) in the nebulised part compared to the non-nebulised which can be overcome by increasing the amount of Lipofectamine. However, Lipofectamine was more than three times more efficient in transfecting 16HBE than DMRIE and linear PEI performed almost 10 times better than its branched derivative. By contrast, the nebulisation process did not affect the cationic polymer complexes. Furthermore, aerosolisation of IVT mRNA complexes did neither affect the protein duration nor the toxicity of the cationic complexes. Taken together, these data show that aerosolisation of cationic IVT mRNA complexes constitute a potentially powerful means to transfect cells in the lung with the purpose of protein replacement for genetic diseases such as cystic fibrosis or alpha-1-antitrypsin deficiency or for infectious disease vaccines, while bringing along the advantages of IVT mRNA as compared to pDNA as transfection agent.