1. Cell size dynamics and viability of cells exposed to hypotonic treatment and electroporation for electrofusion optimizationMarko Ušaj, Katja Trontelj, Rosana Hudej, Maša Kandušer, Damijan Miklavčič, 2009, original scientific article Abstract: Background. Various electrofusion parameters have to be adjusted to obtain theoptimal electrofusion efficiency. Based on published data, good electrofusion conditions can be achieved with the hypotonic treatment. However, the duration of the hypotonic treatment before electroporation and buffer hypoosmolarity have to be adjusted in order to cause cell swelling, to avoid regulatory volume decrease and to preserve cell viability. The aims of our study were to determine cell size dynamics and viability of four different cell lines in hypotonic buffer and to study the influence of the electroporation on the selected cell line in hypotonic buffer. Materials and methods. Cell size dynamics of different cell lines exposed to hypotonic buffer and electroporation were analyzed by time-resolvedcell size measurements. The viability of hypotonically treated oržand electroporated cells was determined 24 h after the experiment by a modified crystal violet (CV) viability assay. Results. In our experimental conditions the hypotonic treatment at 100 mOsm was efficient for CHO, V79 and B16-F1 cell lines. The optimal duration of the treatment was between two and five minutes. On the other hand the same hypotonic treatment did not cause cell swelling of NS1 cells. Cell swelling was also observed after electroporation of B16-F1 in isotonic buffer and it was amplified when hypotonic buffer was used. In addition, the regulatory volume decrease was successfully inhibited with electroporation. Conclusions. Cell size dynamicsin hypotonic conditions should be studied for each cell line since they differ in their sensitivity to the hypotonic treatment. The inhibition of cell regulatory volume decrease by electroporation may be beneficial in achieving higher electrofusion efficiency. (Abstract truncated at 2000 characters) Keywords: hypotonic treatment, cell swelling, regulatory volume decrease, cell size measurements, viability, electrofusion, electroporation Published in DiRROS: 08.03.2024; Views: 337; Downloads: 102
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2. Non-clinical in vitro evaluation of antibiotic resistance gene-free plasmids encoding human or murine IL-12 intended for first-in-human clinical studyŠpela Kos, Maša Omerzel, Tanja Jesenko, Boštjan Markelc, Urška Kamenšek, Katarina Žnidar, Urška Matkovič, Andrej Renčelj, Gregor Serša, Rosana Hudej, Aneja Tuljak, Matjaž Peterka, Maja Čemažar, 2021, original scientific article Abstract: Interleukin 12 (IL-12) is a key cytokine that mediates antitumor activity of immune cells. To fulfill its clinical potential, the development is focused on localized delivery systems, such as gene electrotransfer, which can provide localized delivery of IL-12 to the tumor microenvironment. Gene electrotransfer of the plasmid encoding human IL-12 is already in clinical trials in USA, demonstrating positive results in the treatment of melanoma patients. To comply with EU regulatory requirements for clinical application, which recommend the use of antibiotic resistance gene-free plasmids, we constructed and developed the production process for the clinical grade quality antibiotic resistance gene-free plasmid encoding human IL-12 (p21-hIL-12-ORT) and its ortholog encoding murine IL-12 (p21-mIL-12-ORT). To demonstrate the suitability of the p21-hIL-12-ORT or p21-mIL-12-ORT plasmid for the first-in-human clinical trial, the biological activity of the expressed transgene, its level of expression and plasmid copy number were determined in vitro in the human squamous cell carcinoma cell line FaDu and the murine colon carcinoma cell line CT26. The results of the non-clinical evaluation in vitro set the basis for further in vivo testing and evaluation of antitumor activity of therapeutic molecules in murine models as well as provide crucial data for further clinical trials of the constructed antibiotic resistance gene-free plasmid in humans. Keywords: interleukin 12, gene electrotransfer, antibiotic resistance, plasmids Published in DiRROS: 07.09.2022; Views: 706; Downloads: 377
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3. Genska terapija v onkologiji, prvi razvojni koraki v SlovenijiMaja Čemažar, Tanja Jesenko, Maša Omerzel, Boštjan Markelc, Urška Kamenšek, Simona Kranjc Brezar, Špela Kos, Urša Lampreht Tratar, Katarina Žnidar, Andrej Renčelj, Urška Matkovič, Teja Valant, Kristina Levpušček, Živa Pišljar, Tilen Komel, Tim Božič, Urša Kešar, Barbara Starešinič, Katja Uršič Valentinuzzi, Monika Savarin, Primož Strojan, Gorana Gašljević, Maja Ota, Aleš Grošelj, Črt Jamšek, Rosana Hudej, Matjaž Peterka, Franc Smrekar, Barbara Hubad, Marjan Hosta, Jaka Kužnik, Alojz Hosta, Damijan Miklavčič, Matej Reberšek, Aleksandra Cvetkoska, Anja Zajc, Janja Dermol-Černe, Nataša Tozon, Nina Milevoj, Alenka Nemec Svete, Gregor Serša, 2022, professional article Abstract: Genska terapija postaja čedalje bolj zanimiva tudi v onkologiji. Med aplikacijami je morda najzanimivejša imunostimulacija. Pripravimo lahko plazmidno DNA, ki nosi zapis za različne imunostimulatorne molekule, ki jih vnesemo v celice tumorjev ali normalnih tkiv. Ta tkiva postanejo proizvajalci teh molekul, ki lahko delujejo lokalno ali pa se izločajo tudi sistemsko v krvni obtok. Ker plazmidna DNA ne prehaja celične membrane, so potrebni dostavni sistemi, virusni ali nevirusni. V naših študijah uporabljamo predvsem nevirusni dostavni sistem – elektroporacijo. Interlevkin 12 (IL-12) je eden od zanimivih citokinov, za katerega je znano protitumorsko delovanje s spodbujanjem imunskega odziva in antiangiogenim delovanjem. Namen projekta SmartGene.si je bil pripraviti plazmid z zapisom za interlevkin 12 (plazmid phIL12) in pripraviti vse potrebno za njegovo klinično testiranje za zdravljenje kožnih tumorjev. V konzorciju smo združili moči s partnerji z akademskega in industrijskega področja. Treba je bilo pripraviti plazmid za uporabo v humani onkologiji po zahtevah Evropske agencije za zdravila (EMA). Za prijavo klinične študije na Javno agencijo za zdravila in medicinske pripomočke (JAZMP) smo morali izvesti tudi vse neklinične raziskave o varnosti in učinkovitosti zdravila. Nato je bilo treba razviti postopek priprave zdravila, zagotoviti primerne prostore za pripravo in izvedbo postopka priprave zdravila. V treh letih smo dosegli vse te zastavljene cilje in dobili dovoljenje za izvajanje klinične študije na kožnih tumorjih, ki ga je izdala JAZMP na osnovi pozitivnega mnenja Komisije Republike Slovenije za medicinsko etiko. Zdaj poteka klinična študija faze I preizkušanja plazmida phIL12 na kožnih tumorjih glave in vratu z namenom preveriti varnost in sprejemljivost genskega elektroprenosa plazmida v tumorje. Cilj študije je prav tako določiti primeren odmerek zdravila, ki bi ga v nadaljnji klinični študiji uporabili kot adjuvantno zdravljenje k ablativnim terapijam, kot sta radioterapija ali elektrokemoterapija. Keywords: genska terapija, interlevkin-12, plazmidna DNA, elektroprenos genov, rak kože Published in DiRROS: 01.07.2022; Views: 1528; Downloads: 295
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