Auflistung nach Autor:in "Geiser, Thomas"

Gerade angezeigt 1 - 11 von 11

A new electrospray method for targeted gene delivery
(Nature, 03/2018) Boehringer, Stephan; Ruzgys, Paulius; Tamò, Luca; Satkauskas, Saulius; Geiser, Thomas; Gazdhar, Amiq; Hradetzky, David
A challenge for gene therapy is absence of safe and efficient local delivery of therapeutic genetic material. An efficient and reproducible physical method of electrospray for localized and targeted gene delivery is presented. Electrospray works on the principle of coulombs repulsion, under influence of electric field the liquid carrying genetic material is dispersed into micro droplets and is accelerated towards the targeted tissue, acting as a counter electrode. The accelerated droplets penetrate the targeted cells thus facilitating the transfer of genetic material into the cell. The work described here presents the principle of electrospray for gene delivery, the basic instrument design, and the various optimized parameters to enhance gene transfer in vitro. We estimate a transfection efficiency of up to 60% was achieved. We describe an efficient gene transfer method and a potential electrospray-mediated gene transfer mechanism.
01A - Beitrag in wissenschaftlicher Zeitschrift
AI based profit strategies in a smart energy market
(Hochschule für Wirtschaft FHNW, 2018) Geiser, Thomas; Wache, Holger
This master’s thesis proposes an approach to predict prices in a smart grid’s energy trading market using artificial neural networks to maximize the profit of a participating household. Because energy demand and supply must be balanced at all times to guarantee the stability of the energy grid, producers, wholesalers and brokers are equally interested in keeping the equilibrium to prevent blackouts, poor customer satisfaction and the respective costs. In the past couple of years, the ever-expanding energy demand and the addition of volatile renewable resources into the energy system has created new challenges. Recent advances in information technologies, on the other hand, introduce possibilities of how to tackle these challenges ahead. One approach is to decentralize the energy distribution and having smart microgrids balancing the demand and supply within themselves, stabilizing the whole system in the process. To do so, the Smart Stability Network incorporates an auction scheme where each participating household can offer to produce or consume energy for a price. Because market participants usually act selfishly and want to increase their profits, knowing the ideal price to win the auction in advance would enable them to maximize their profit and ensure their active participation in stabilizing the grid....
11 - Studentische Arbeit
An approach towards bronchoscopic-based gene therapy using electrical field accelerated plasmid droplets
(IEEE, 2012) Hradetzky, David; Boehringer, Stephan; Geiser, Thomas; Gazdhar, Amiq
Idiopathic pulmonary fibrosis (IPF) is a devastating disease affecting the distal lung, due to failure of the alveolar epithelium to heal after micro-injuries, leading to inefficient gas exchange and resulting in death. Therapeutic options are very limited. A new therapeutic approach based on gene therapy restores the self-healing process within the lung in the experimental setup. A basic requirement of this therapy is the successful transduction of genes into the alveolar epithelium in the distal part of the lung, for which a new therapeutic instrument is required. In this paper we present the concept and first experimental results of a device which uses an electrical field to accelerate the charged droplets of plasmid suspension toward the tissue and which overcomes cell membrane with its impact energy. The aim is to develop a therapeutic device capable of being integrated into minimally invasive procedures such as bronchoscopy.
04B - Beitrag Konferenzschrift
Best-match in a set of single-vehicle dynamic pickup and delivery problem using ant colony optimization
(2020) Geiser, Thomas; Hanne, Thomas; Dornberger, Rolf
04B - Beitrag Konferenzschrift
Design of miniaturized electro spray instrument for gene and drug therapeutic treatment of IPF
(De Gruyter, 2013) Fiave, Prosper Agbesi; Boehringer, Stephan; Gazdhar, Amiq; Geiser, Thomas; Hradetzky, David
Electric field accelerated plasmid droplets to permeate tissues has been demonstrated on cell culture and ex-vivo lung tissue of rats using enhanced green fluorescence protein reporter gene for transfection. This opens a window of opportunity to design an electrospray instrument usable within the working channel of bronchoscope to noninvasively treat idiopathic pulmonary fibrosis (IPF). We elaborate a concept and realized a device usable in the working channel of a flexible bronchoscope taking into account restrictions within typical bronchoscopy procedure.
01A - Beitrag in wissenschaftlicher Zeitschrift
Electrospray application for enchanced delivery of anticancer drugs into cells
(Vytautas Magnus university, 2018) Ruzgys, Paulius; Boehringer, Stephan; Tamò, Luca; Šatkauskas, Saulius; Geiser, Thomas; Gazdhar, Amiq; Hradetzky, David
Electrospray is a process based on applied high electric voltage on liquid, leading to the creation and acceleration of small sized droplets. Electrosprayed suspension with exogenous molecules on cells can trigger intracellular delivery. Here, the application study of anticancer drug delivery via electrospray as an antitumor treatment is presented in vitro and in vivo. In vitro experiments were performed on alveolar epithelial cells (A549). Cell viability was performed with flow cytometry assay. Apoptosis/ necrosis was measured using annexin V/PI kit. In vivo experiments were done with C57BL/6J mice. Lewis lung carcinoma (LLC) cell lines were injected intradermally to induce tumor. Electrospray was performed on tumor by cutting the skin. Tumor size was measured with caliper. Results show triggered PI transfer to cells after electrospray process. Moreover, obtained results in vitro showed successful cisplatin and methotrexate intracellular delivery, resulting in around 90 % of cell viability loss with methotrexate and 70 % of cell viability loss with cisplatin. In vivo experiments reveled a tumor decrease by around 2.5 times in 7 days after electrospray treatment at first and third day with both anticancer drugs. Here we show that electrospray method can be applied to local anticancer drug delivery to cells and tissues. Therefore, such method might be adapted as a clinical anticancer therapy in the future.
04B - Beitrag Konferenzschrift
Electrospray mediated localized and targeted chemotherapy in a mouse model of lung cancer
(Frontiers, 21.04.2021) Hradetzky, David; Gazdhar, Amiq; Ruzgys, Paulius; Böhringer, Stephan; Sila Dokumaci, Ayse; Hari, Yvonne; Schürch, Christian; Brühl, Frido; Schürch, Stefan; Sönke, Szidat; Riether, Carsten; Satkauskas, Saulius; Geiser, Thomas
An advanced stage, centrally localized invasive tumor is a major cause of sudden death in lung cancer patients. Currently, chemotherapy, radiotherapy, laser ablation, or surgical resection if possible are the available state-of-the-art treatments but none of these guarantee remedy or long-term relief and are often associated with fatal complications. Allowing localized chemotherapy, by direct and confined drug delivery only at the tumor site, could be a promising option for preoperative down staging or palliative therapy. Here we report the localized and targeted application of intra tumor delivery of chemotherapeutics using a novel device based on the principle of electrospray.
01A - Beitrag in wissenschaftlicher Zeitschrift
Electrospray-mediated local chemotherapy of lung carcinoma in mice
(European Respiratory Society, 2016) Hradetzky, David; Böhringer, Stephan; Satkauskas, Saulius; Geiser, Thomas; Gazdhar, Amiq; Ruzgys, Paulius
01A - Beitrag in wissenschaftlicher Zeitschrift
Electrospray: efficient gene delivery method to lung cells
(2015) Ruzgys, Paulius; Boehringer, Stephan; Šatkauskas, Saulius; Hradetzky, David; Gazdhar, Amiq; Geiser, Thomas
06 - Präsentation
Method for analysis of electrospray for gene transfer and the impact on cell viability of A549 alveolar epithelial like cells
(IEEE, 2018) Hradetzky, David; Boehringer, Stephan; Ruzgys, Paulius; Šatkauskas, Saulius; Geiser, Thomas; Gazdhar, Amiq
Electrospray is a process based on creation and acceleration of small sized droplets based on electrostatic repulsion. Spraying plasmid containing liquids this process may be used to transfer genes into cells. Within this paper we report on a method for accessing and evaluating the spray modalities using high speed imaging system with a post processing of image data to obtain estimated volume and velocity of emerging droplets first. Second we investigate on the impact of different media on the spray modalities. Third we evaluate the impact of the spray on cell viability and on transfection efficiency of an eGFP plasmid as reporter gene obtained in an in vitro setup on alveolar epithelial like cells (A549).
04B - Beitrag Konferenzschrift
The impact of electrospray driven aerosols on the in vitro transfection efficiency for targeted gene and drug delivery
(2016) Hradetzky, David; Boehringer, Stephan; Ruzgys, Paulius; Satkauskas, Saulius; Gazdhar, Amiq; Geiser, Thomas
06 - Präsentation