TY  - JOUR
AB  - The delivery of vaccines plays a pivotal role in influencing the strength and longevity of the immune response and controlling reactogenicity. Mucosal immunization, as compared to parenteral vaccination, could offer greater protection against respiratory infections while being less invasive. While oral vaccination has been presumed less effective and believed to target mainly the gastrointestinal tract, trans-buccal delivery using mucoadhesive films (MAF) may allow targeted delivery to the mucosa. Here we present an effective strategy for mucosal delivery of several vaccine platforms incorporated in MAF, including DNA plasmids, viral vectors, and lipid nanoparticles incorporating mRNA (mRNA/LNP). The mRNA/LNP vaccine formulation targeting SARS-CoV-2 as a proof of concept remained stable within MAF consisting of slowly releasing water-soluble polymers and an impermeable backing layer, facilitating enhanced penetration into the oral mucosa. This formulation elicited antibody and cellular responses comparable to the intramuscular injection, but also induced the production of mucosal IgAs, highlighting its efficacy, particularly for use as a booster vaccine and the potential advantage for protection against respiratory infections. The MAF vaccine preparation demonstrates significant advantages, such as efficient delivery, stability, and simple noninvasive administration with the potential to alleviate vaccine hesitancy.
AU  - Esih, H.*
AU  - Mezgec, K.*
AU  - Billmeier, M.*
AU  - Malenšek, Š.*
AU  - Benčina, M.*
AU  - Grilc, B.*
AU  - Vidmar, S.*
AU  - Gašperlin, M.*
AU  - Bele, M.*
AU  - Zidarn, M.*
AU  - Zupanc, T.L.*
AU  - Morgan, T.*
AU  - Jordan, I.*
AU  - Sandig, V.*
AU  - Schrödel, S.*
AU  - Thirion, C.*
AU  - Protzer, U.
AU  - Wagner, R.*
AU  - Lainšček, D.*
AU  - Jerala, R.*
C1  - 70767
C2  - 55738
SP  - 179-192
TI  - Mucoadhesive film for oral delivery of vaccines for protection of the respiratory tract.
JO  - J. Control. Release
VL  - 371
PY  - 2024
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - Cyanine derivatives are organic dyes widely used for optical imaging. However, their potential in longitudinal optoacoustic imaging and photothermal therapy remains limited due to challenges such as poor chemical stability, poor photostability, and low photothermal conversion. In this study, we present a new structural modification for cyanine dyes by introducing a strongly electron-withdrawing group (barbiturate), resulting in a new series of barbiturate-cyanine dyes (BC810, BC885, and BC1010) with suppressed fluorescence and enhanced stability. Furthermore, the introduction of BC1010 into block copolymers (PEG114-b-PCL60) induces aggregation-caused quenching, further boosting the photothermal performance. The photophysical properties of nanoparticles (BC1010-NPs) include their remarkably broad absorption range from 900 to 1200 nm for optoacoustic imaging, allowing imaging applications in NIR-I and NIR-II windows. The combined effect of these strategies, including improved photostability, enhanced nonradiative relaxation, and aggregation-caused quenching, enables the detection of optoacoustic signals with high sensitivity and effective photothermal treatment of in vivo tumor models when BC1010-NPs are administered before irradiation with a 1064 nm laser. This research introduces a barbiturate-functionalized cyanine derivative with optimal properties for efficient optoacoustics-guided theranostic applications. This new compound holds significant potential for biomedical use, facilitating advancements in optoacoustic-guided diagnostic and therapeutic approaches.
AU  - Liu, N.
AU  - O'Connor, P.
AU  - Gujrati, V.
AU  - Shelar, D.
AU  - Ma, X.*
AU  - Anzenhofer,P.
AU  - Klemm, U.
AU  - Su, X.*
AU  - Huang, Y.*
AU  - Kleigrewe, K.*
AU  - Feuchtinger, A.
AU  - Walch, A.K.
AU  - Sattler, M.
AU  - Plettenburg, O.
AU  - Ntziachristos, V.
C1  - 70880
C2  - 55834
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
SP  - 522-530
TI  - Tuning the photophysical properties of cyanine by barbiturate functionalization and nanoformulation for efficient optoacoustics- guided phototherapy.
JO  - J. Control. Release
VL  - 372
PB  - Elsevier
PY  - 2024
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - The blood-brain barrier (BBB) is a highly selective biological barrier that represents a major bottleneck in the treatment of all types of central nervous system (CNS) disorders. Small interfering RNA (siRNA) offers in principle a promising therapeutic approach, e.g., for brain tumors, by downregulating brain tumor-related genes and inhibiting tumor growth via RNA interference. In an effort to develop efficient siRNA nanocarriers for crossing the BBB, we utilized polyethyleneimine (PEI) polymers hydrophobically modified with either stearic-acid (SA) or dodecylacrylamide (DAA) subunits and evaluated their suitability for delivering siRNA across the BBB in in vitro and in vivo BBB models depending on their structure. Physicochemical characteristics of siRNA-polymer complexes (polyplexes (PXs)), e.g., particle size and surface charge, were measured by dynamic light scattering and laser Doppler anemometry, whereas siRNA condensation ability of polymers and polyplex stability was evaluated by spectrophotometric methods. The composition of the biomolecule corona that absorbs on polyplexes upon encountering physiological fluids was investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and by a liquid chromatography-tandem mass spectrometry (LC-MS-MS) method. Cellular internalization abilities of PXs into brain endothelial cells (hCMEC/D3) was confirmed, and a BBB permeation assay using a human induced pluripotent stem cell (hiPSC)-derived BBB model revealed similar abilities to cross the BBB for all formulations under physiological conditions. However, biodistribution studies of radiolabeled PXs in mice were inconsistent with in vitro results as the detected amount of radiolabeled siRNA in the brain delivered with PEI PXs was higher compared to PEI-SA PXs. Taken together, PEI PXs were shown to be a suitable nanocarrier to deliver small amounts of siRNA across the BBB into the brain but more sophisticated human BBB models that better represent physiological conditions and biodistribution are required to provide highly predictive in vitro data for human CNS drug development in the future.
AU  - Hartl, N.*
AU  - Gabold, B.*
AU  - Adams, F.*
AU  - Uhl, P.*
AU  - Oerter, S.*
AU  - Gätzner, S.*
AU  - Metzger, M.*
AU  - König, A.-C.
AU  - Hauck, S.M.
AU  - Appelt-Menzel, A.*
AU  - Mier, W.*
AU  - Fricker, G.*
AU  - Merkel, O.M.*
C1  - 68114
C2  - 54592
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
SP  - 613-629
TI  - Overcoming the blood-brain barrier? - prediction of blood-brain permeability of hydrophobically modified polyethylenimine polyplexes for siRNA delivery into the brain with in vitro and in vivo models.
JO  - J. Control. Release
VL  - 360
PB  - Elsevier
PY  - 2023
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - GATA3 gene silencing in activated T cells displays a promising option to early-on undermine pathological pathways in the disease formation of allergic asthma. The central transcription factor of T helper 2 (Th2) cell cytokines IL-4, IL-5, and IL-13 plays a major role in immune and inflammatory cascades underlying asthmatic processes in the airways. Pulmonary delivery of small interfering RNAs (siRNA) to induce GATA3 knockdown within disease related T cells of asthmatic lungs via RNA interference (RNAi) presents an auspicious base to realize this strategy, however, still faces some major hurdles. Main obstacles for successful siRNA delivery in general comprise stability and targeting issues, while in addition the transfection of T cells presents a particularly challenging task itself. In previous studies, we have developed and advanced an eligible siRNA delivery system composed of polyethylenimine (PEI) as polycationic carrier, transferrin (Tf) as targeting ligand and melittin (Mel) as endosomolytic agent. Resulting Tf-Mel-PEI polyplexes exhibited ideal characteristics for targeted siRNA delivery to activated T cells and achieved efficient and sequence-specific gene knockdown in vitro. In this work, the therapeutic potential of this carrier system was evaluated in an optimized cellular model displaying the activated status of asthmatic T cells. Moreover, a suitable siRNA sequence combination was found for effective gene silencing of GATA3. To confirm the translatability of our findings, Tf-Mel-PEI polyplexes were additionally tested ex vivo in activated human precision-cut lung slices (PCLS). Here, the formulation showed a safe profile as well as successful delivery to the lung epithelium with 88% GATA3 silencing in lung explants. These findings support the feasibility of Tf-Mel-PEI as siRNA delivery system for targeted gene knockdown in activated T cells as a potential novel therapy for allergic asthma.
AU  - Kandil, R.*
AU  - Baldassi, D.*
AU  - Böhlen, S.*
AU  - Müller, J.T.*
AU  - Jürgens, D.C.*
AU  - Bargmann, T.*
AU  - Dehmel, S.*
AU  - Xie, Y.*
AU  - Mehta, A.
AU  - Sewald, K.*
AU  - Merkel, O.M.
C1  - 67207
C2  - 54218
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
SP  - 305-315
TI  - Targeted GATA3 knockdown in activated T cells via pulmonary siRNA delivery as novel therapy for allergic asthma.
JO  - J. Control. Release
VL  - 354
PB  - Elsevier
PY  - 2023
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - SARS-CoV-2 has been the cause of a global pandemic since 2019 and remains a medical urgency. siRNA-based therapies are a promising strategy to fight viral infections. By targeting a specific region of the viral genome, siRNAs can efficiently downregulate viral replication and suppress viral infection. However, to achieve the desired therapeutic activity, siRNA requires a suitable delivery system. The VIPER (virus-inspired polymer for endosomal release) block copolymer has been reported as promising delivery system for both plasmid DNA and siRNA in the past years. It is composed of a hydrophilic block for condensation of nucleic acids as well as a hydrophobic, pH-sensitive block that, at acidic pH, exposes the membrane lytic peptide melittin, which enhances endosomal escape. In this study, we aimed at developing a formulation for pulmonary administration of siRNA to suppress SARS-CoV-2 replication in lung epithelial cells. After characterizing siRNA/VIPER polyplexes, the activity and safety profile were confirmed in a lung epithelial cell line. To further investigate the activity of the polyplexes in a more sophisticated cell culture system, an air-liquid interface (ALI) culture was established. siRNA/VIPER polyplexes reached the cell monolayer and penetrated through the mucus layer secreted by the cells. Additionally, the activity against wild-type SARS-CoV-2 in the ALI model was confirmed by qRT-PCR. To investigate translatability of our findings, the activity against SARS-CoV-2 was tested ex vivo in human lung explants. Here, siRNA/VIPER polyplexes efficiently inhibited SARS-CoV-2 replication. Finally, we verified the delivery of siRNA/VIPER polyplexes to lung epithelial cells in vivo, which represent the main cellular target of viral infection in the lung. In conclusion, siRNA/VIPER polyplexes efficiently delivered siRNA to lung epithelial cells and mediated robust downregulation of viral replication both in vitro and ex vivo without toxic or immunogenic side effects in vivo, demonstrating the potential of local siRNA delivery as a promising antiviral therapy in the lung.
AU  - Baldassi, D.*
AU  - Ambike, S.
AU  - Feuerherd, M.
AU  - Cheng, C.-C.
AU  - Peeler, D.J.*
AU  - Feldmann, D.P.*
AU  - Porras-Gonzalez, D.L.
AU  - Wei, X.
AU  - Keller, L.A.*
AU  - Kneidinger, N.
AU  - Stoleriu, M.G.*
AU  - Popp, A.*
AU  - Burgstaller, G.
AU  - Pun, S.H.*
AU  - Michler, T.
AU  - Merkel, O.M.
C1  - 64816
C2  - 51975
SP  - 661-674
TI  - Inhibition of SARS-CoV-2 replication in the lung with siRNA/VIPER polyplexes.
JO  - J. Control. Release
VL  - 345
PY  - 2022
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - While all the siRNA drugs on the market target the liver, the lungs offer a variety of currently undruggable targets which could potentially be treated with RNA therapeutics. Hence, local, pulmonary delivery of RNA nanoparticles could finally enable delivery beyond the liver. The administration of RNA drugs via dry powder inhalers offers many advantages related to physical, chemical and microbial stability of RNA and nanosuspensions. The present study was therefore designed to test the feasibility of engineering spray dried lipid nanoparticle (LNP) powders. Spray drying was performed using 5% lactose solution (m/V), and the targets were set to obtain nanoparticle sizes after redispersion of spray-dried powders around 150 nm, a residual moisture level below 5%, and RNA loss below 15% at maintained RNA bioactivity. The LNPs consisted of an ionizable cationic lipid which is a sulfur-containing analog of DLin-MC3-DMA, a helper lipid, cholesterol, and PEG-DMG encapsulating siRNA. Prior to the spray drying, the latter process was simulated with a novel dual emission fluorescence spectroscopy method to preselect the highest possible drying temperature and excipient solution maintaining LNP integrity and stability. Through characterization of physicochemical and aerodynamic properties of the spray dried powders, administration criteria for delivery to the lower respiratory tract were fulfilled. Spray dried LNPs penetrated the lung mucus layer and maintained bioactivity for >90% protein downregulation with a confirmed safety profile in a lung adenocarcinoma cell line. Additionally, the spray dried LNPs successfully achieved up to 50% gene silencing of the house keeping gene GAPDH in ex vivo human precision-cut lung slices at without increasing cytokine levels. This study verifies the successful spray drying procedure of LNP-siRNA systems maintaining their integrity and mediating strong gene silencing efficiency on mRNA and protein levels both in vitro and ex vivo. The successful spray drying procedure of LNP-siRNA formulations in 5% lactose solution creates a novel siRNA-based therapy option to target respiratory diseases such as lung cancer, asthma, COPD, cystic fibrosis and viral infections.
AU  - Zimmermann, C.M.*
AU  - Baldassi, D.*
AU  - Chan, K.*
AU  - Adams, N.B.P.*
AU  - Neumann, A.*
AU  - Porras-Gonzalez, D.L.
AU  - Wei, X.
AU  - Kneidinger, N.*
AU  - Stoleriu, M.G.*
AU  - Burgstaller, G.
AU  - Witzigmann, D.*
AU  - Luciani, P.*
AU  - Merkel, O.M.
C1  - 66285
C2  - 52770
SP  - 137-150
TI  - Spray drying siRNA-lipid nanoparticles for dry powder pulmonary delivery.
JO  - J. Control. Release
VL  - 351
PY  - 2022
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - The complexity of lung diseases makes pre-clinical in vivo respiratory research in mouse lungs of great importance for a better understanding of physiology and therapeutic effects. Synchrotron-based imaging has been successfully applied to lung research studies, however longitudinal studies can be difficult to perform due to limited facility access. Laboratory-based x-ray sources, such as inverse Compton x-ray sources, remove this access limitation and open up new possibilities for pre-clinical small-animal lung research at high spatial and temporal resolution. The in vivo visualization of drug deposition in mouse lungs is of interest, particularly in longitudinal research, because the therapeutic outcome is not only dependent on the delivered dose of the drug, but also on the spatial distribution of the drug. An additional advantage of this approach, when compared to other imaging techniques, is that anatomic and dynamic information is collected simultaneously. Here we report the use of dynamic x-ray phase-contrast imaging to observe pulmonary drug delivery via liquid instillation, and by inhalation of micro-droplets. Different liquid volumes (4 μl, 20 μl, 50 μl) were tested and a range of localized and global distributions were observed with a temporal resolution of up to 1.5 fps. The in vivo imaging results were confirmed by ex vivo x-ray and fluorescence imaging. This ability to visualize pulmonary substance deposition in live small animals has provided a better understanding of the two key methods of delivery; instillation and nebulization.
AU  - Gradl, R.*
AU  - Dierolf, M.*
AU  - Yang, L.
AU  - Hehn, L.*
AU  - Günther, B.*
AU  - Möller, W.
AU  - Kutschke, D.
AU  - Stöger, T.
AU  - Gleich, B.*
AU  - Achterhold, K.*
AU  - Donnelley, M.*
AU  - Pfeiffer, F.*
AU  - Schmid, O.
AU  - Morgan, K.S.*
C1  - 56415
C2  - 47058
SP  - 282-291
TI  - Visualizing treatment delivery and deposition in mouse lungs using in vivo x-ray imaging.
JO  - J. Control. Release
VL  - 307
PY  - 2019
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - Magnetic nanoparticles are highly desirable for biomedical research and treatment of cancer especially when combined with hyperthermia. The efficacy of nanoparticle-based therapies could be improved by generating radioactive nanoparticles with a convenient decay time and which simultaneously have the capability to be used for locally confined heating. The core–shell morphology of such novel nanoparticles presented in this work involves a polysilico-tungstate molecule of the polyoxometalate family as a precursor coating material, which transforms into an amorphous tungsten oxide coating upon annealing of the FePt core–shell nanoparticles. The content of tungsten atoms in the nanoparticle shell is neutron activated using cold neutrons at the Heinz Maier-Leibnitz (FRMII) neutron facility and thereby transformed into the radioisotope W-187. The sizeable natural abundance of 28% for the W-186 precursor isotope, a radiopharmaceutically advantageous gamma–beta ratio of γβ≈30% and a range of approximately 1 mm in biological tissue for the 1.3 MeV β-radiation are promising features of the nanoparticles' potential for cancer therapy. Moreover, a high temperature annealing treatment enhances the magnetic moment of nanoparticles in such a way that a magnetic heating effect of several degrees Celsius in liquid suspension – a prerequisite for hyperthermia treatment of cancer – was observed. A rise in temperature of approximately 3 °C in aqueous suspension is shown for a moderate nanoparticle concentration of 0.5 mg/ml after 15 min in an 831 kHz high-frequency alternating magnetic field of 250 Gauss field strength (25 mT). The biocompatibility based on a low cytotoxicity in the non-neutron-activated state in combination with the hydrophilic nature of the tungsten oxide shell makes the coated magnetic FePt nanoparticles ideal candidates for advanced radiopharmaceutical applications.
AU  - Seemann, K.M.*
AU  - Luysberg, M.*
AU  - Revay, Z.*
AU  - Kudejova, P.*
AU  - Sague, B.S.*
AU  - Cassinelli, N.*
AU  - Loidl, A.*
AU  - Ilicic, K.*
AU  - Multhoff, G.
AU  - Schmid, T.E.
C1  - 42844
C2  - 35420
SP  - 131-137
TI  - Magnetic heating properties and neutron activation of tungsten-oxide coated biocompatible FePt core-shell nanoparticles.
JO  - J. Control. Release
VL  - 197
PY  - 2014
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - Nanoparticles (NP) as carriers for anti-cancer drugs have shown great promise. Specific targeting of NP to malignant cells, however, remains an unsolved problem. Conjugation of antibodies specific for tumor membrane antigens to NP represents one approach to improve specificity and to increase therapeutic efficacy. In the present study, for the first time a novel membrane heat shock protein (Hsp70)-specific antibody (cmHsp70.1) was coupled to human serum albumin (HSA) NP, loaded with microRNA (miRNA) plasmids to target the inhibitor of apoptosis protein survivin. The physicochemical properties of monodisperse miRNA-loaded NP showed a diameter of 180nm to 220nm, a plasmid incorporation of more than 95% and a surface binding capacity of the antibody of 70-80%. Antibody-conjugated NP displayed an increased cellular uptake in U87MG and LN229 glioblastoma cells compared to isotype control antibody, PEG-coupled controls and peripheral blood lymphocytes (PBL). Survivin expression was significantly reduced in cells treated with the Hsp70-miRNA-NP as compared to non-conjugated NP. Hsp70-miRNA-NP enhanced radiation-induced increase in caspase 3/7 activity and decrease in clonogenic cell survival. In summary, cmHsp70.1 miRNA-NP comprise an enhanced tumor cell uptake and increased therapeutic efficacy of radiation therapy in vitro and provide the basis for the development of antibody-based advanced carrier systems for a tumor cell specific targeting.
AU  - Gaca, S.*
AU  - Reichert, S.*
AU  - Multhoff, G.
AU  - Wacker, M.*
AU  - Hehlgans, S.*
AU  - Botzler, C.*
AU  - Gehrmann, M.*
AU  - Rödel, C.*
AU  - Kreuter, J.*
AU  - Rödel, F.*
C1  - 27447
C2  - 32674
SP  - 201-206
TI  - Targeting by cmHsp70.1-antibody coated and survivin miRNA plasmid loaded nanoparticles to radiosensitize glioblastoma cells.
JO  - J. Control. Release
VL  - 172
IS  - 1
PB  - Elsevier Science
PY  - 2013
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - Thermosensitive liposomes (TSL) with encapsulated magnetic resonance imaging (MRI) longitudinal relaxation time (T-1) contrast agents (CAs) have been proposed for MRI assisted interventional thermotherapy in solid tumors. Here the feasibility of 6 clinically approved CAs (Gd-DTPA, Gd-BOPTA, Gd-DOTA, Gd-BT-DO3A, Gd-DTPA-BMA, and Gd-HP-DO3A) for formulation into TSL was investigated. CAs were passively encapsulated with 323 mOs kg(-1) into 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/1,2-distearoyl-sn-glycero-3-phosphocholine/1,2-dipalmitoyl-sn-glycero-3-phosphodiglycerol 50/20/30 (mol/mol) TSL (DPPG(2)-TSL) to obtain stable formulations. T-1 relaxivity (r(1)) and diffusive permeability to water (P-d) across the membrane were determined. Shelf life at 4 degrees C was investigated by determining lysolipid content up to 10 weeks after preparation. All preparations were monodispersed with comparable small vesicle sizes (similar to 135 nm). Neither zeta potential nor phase transition temperature (T-m) was affected by the CA. The formulations showed an increase in r1 in the temperature range between 38 and 44 degrees C. This correlated with the phase transition.
AU  - Hossann, M.
AU  - Wang, T.
AU  - Syunyaeva, Z.*
AU  - Wiggenhorn, M.*
AU  - Zengerle, A.*
AU  - Issels, R.D.
AU  - Reiser, M.*
AU  - Lindner, L.H.
AU  - Peller, M.*
C1  - 23647
C2  - 31264
SP  - 22-29
TI  - Non-ionic Gd-based MRI contrast agents are optimal for encapsulation into phosphatidyldiglycerol-based thermosensitive liposomes.
JO  - J. Control. Release
VL  - 166
IS  - 1
PB  - Elsevier Science
PY  - 2013
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - Liposome mediated anticancer drug delivery has the advantage of reducing cytotoxicity in healthy tissues. However, undesired slow drug release impedes the therapeutic efficacy of clinically applied PEG-liposomal doxorubicin (Dox). The aim of this study is to combine stealth thermosensitive liposomes (TSL) and local mild hyperthermia (HT) to increase bioavailable Dox levels in tumors. Dox was encapsulated in stealth TSL (similar to 80 nm) with optimized PEG concentration in the membrane, and compared with lysolipid-based Dox-LTSL for in vitro stability, release kinetics, and in vivo tumor growth control. In vitro cytotoxicity of Dox-TSL against murine BFS-1 sarcoma and, human BLM melanoma cell lines and Human Umbilical Vein Endothelial Cells (HUVEC) under normothermia (37 degrees C) and HT (42 degrees C) was compared with non-encapsulated Dox. In vitro Dox uptake in nuclei was imaged in BLM and HUVEC. In vivo intravascular Dox release from TSL in BFS-1 tumors under local mild HT in dorsal skin flap window chamber models was captured by intravital confocal microscopy. Intravascular Dox-TSL release kinetics, penetration depth and interstitial Dox density were subjected to quantitative image analysis. Systemic Dox-TSL administration in combination with local mild HT on subcutaneous tumor growth control was compared to Dox-LTSL plus local mild HT. Dox-TSL was stable at 37 degrees C, while released over 95% Dox within 1 min in 90% serum at 42 degrees C. Dox-TSL demonstrated efficient in vivo intratumoral Dox release under local mild HT, followed by significant Dox uptake by tumor and tumor vascular endothelial cells. Dox-TSL plusmild HT showed improved tumor growth control over Dox-LTSL plus mild HT. Survival after a single treatment of Dox-TSL plus mild HT was 67%, while survival after Dox-LTSL plusmild HT was 22%. This combination of Dox-TSL and local mild HT offers promising clinical opportunities to improve liposomal Dox delivery to solid tumors.
AU  - Li, L.*
AU  - ten Hagen, T.L.M.*
AU  - Hossann, M.
AU  - Süss, R.*
AU  - van Rhoon, G.C.*
AU  - Eggermont, A.M.M.*
AU  - Haemmerich, D.*
AU  - Koning, G.A.*
C1  - 25501
C2  - 31877
SP  - 142-150
TI  - Mild hyperthermia triggered doxorubicin release from optimized stealth thermosensitive liposomes improves intratumoral drug delivery and efficacy.
JO  - J. Control. Release
VL  - 168
IS  - 2
PB  - Elsevier Science
PY  - 2013
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - Thermosensitive liposomes (TSL) are a promising tool for triggered drug delivery in combination with local hyperthermia. Objective of this study was to investigate the influence of serum on TSL in more detail and to identify serum components which are responsible for increasing drug release. Four different formulations were investigated: DPPC/DSPC/1,2-dipalmitoyl-sn-glycero-3-phosphodiglycerol (DPPG(2)) 50/20/30 (mol/mol) (DPPG(2)-TSL); DPPC/DSPC/DPPG(2)/DSPE-PEG2000 50/15/30/5 (mol/mol) (DPPG(2)/PEG-TSL), DPPC/P-Lyso-PC/DSPE-PEG2000 90/10/4 (mol/mol) (PEG/Lyso-TSL), and DPPC/DSPC/DSPE-PEG2000 80/15/5 (mol/mol) (PEG-TSL). DPPG(2)-TSL was the only formulation which was unaffected by osmotic stress. All formulations tested were influenced by serum components but the susceptibility was depended on the lipid composition of the vesicle. Presence of albumin (HSA) or cholesterol-containing lipid vesicles (DPPC/Chol-LLV) increased the membrane permeability for all tested formulations at temperatures around and above T(m) in a concentration based manner. PEGylation was not able to prevent the observed effect. PEG-TSL and PEG/Lyso-TSL were more susceptible to DPPC/Chol-LLV than DPPG(2)-containing TSL. In contrast, immunoglobulin type G (IgG) affected only anionic formulations. The membrane of DPPG(2)-TSL and DPPG(2)/PEG-TSL was more susceptible toward IgG as compared to HSA. DPPG(2)-TSL and PEG/Lyso-TSL were differentially influenced by fetal calf serum (FCS). As DPPG(2)-TSL was stabilized by pre-incubation with FCS at 37°C, this was the opposite for PEG/Lyso-TSL which were destabilized under these conditions. Individual serum components were unable to mimic the complex situation in full serum. Hence, the use of plasma or serum is still inevitable to investigate stability and release properties of novel TSL formulations until all serum components have been identified that alter TSL integrity.
AU  - Hossann, M.
AU  - Syunyaeva, Z.*
AU  - Schmidt, R.*
AU  - Zengerle, A.*
AU  - Eibl, H.*
AU  - Issels, R.D.
AU  - Lindner, L.H.
C1  - 11075
C2  - 30497
SP  - 400-406
TI  - Proteins and cholesterol lipid vesicles are mediators of drug release from thermosensitive liposomes.
JO  - J. Control. Release
VL  - 162
IS  - 2
PB  - Elsevier Science
PY  - 2012
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - Pulmonary siRNA delivery offers a new way to treat various lung diseases. Poly(ethylene imines) (PEIs) are promising cationic nanocarriers and various modifications are still under investigations to improve their cytotoxicity and efficacy for siRNA delivery. In this study, we analyzed two different types of PEI-based nanocomplexes in mice after intratracheal administration regarding their toxicity and efficacy in the lungs. Ubiquitously enhanced green fluorescent protein (EGFP) expressing transgenic and BALB/c mice were intratracheally instilled with 35μg siRNA complexed with the different types of PEI nanocarriers. Lung toxicity and inflammation were investigated after 24h, 3d and 7d treatment and knockdown of EGFP expression was analyzed by flow cytometry and fluorescence microscopy five days post instillation. Three different polyplexes caused more than 60% knockdown of EGFP expression, but only the fatty acid modified low molecular weight PEI 8.3kDa (C16-C18-EO25)1.4 specifically reduced EGFP expression in CD45+ leucocytes (25±12%) and CD11b-/CD11c+ lung macrophages (36±14%). Hydrophobic and hydrophilic PEG modifications on PEI caused severe inflammatory response and elevated levels of IgM in broncho-alveolar fluid (BALF). Thus, the PEG modification reduced cytotoxicity, but elevated the immune response and proinflammatory effects. Further investigations of the proinflammatory and immunomodulatory effects of the PEI-modified carriers are necessary to clarify the highly unspecific knockdown effects in the lung in more detail. Nevertheless, the more hydrophobic modification of PEI based non-viral vector system appeared to be a promising approach for improved siRNA therapeutics offering successful pulmonary siRNA delivery.
AU  - Beyerle, A.*
AU  - Braun, A.
AU  - Merkel, O.*
AU  - Koch, F.*
AU  - Kissel, T.*
AU  - Stöger, T.
C1  - 6403
C2  - 28619
SP  - 51-56
TI  - Comparative in vivo study of poly(ethylene imine)/siRNA complexes for pulmonary delivery in mice.
JO  - J. Control. Release
VL  - 151
IS  - 1
PB  - Elsevier
PY  - 2011
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - Thermosensitive liposomes (TSL) in combination with regional hyperthermia represent a powerful tool for tumor specific drug delivery. The objective of this study was to investigate the influence of vesicle size on the biophysical properties of TSL TSL were composed of DPPC/DSPC/1,2-dipalmitoyl-sn-glycero-3-phosphoglyceroglycerol (DPPG(2)) 50:20:30 (mol/mol) (DPPG(2)-TSL) and DPPC/P-Lyso-PC/DSPE-PEG2000 90:10:4 (mol/mol) (PEG/Lyso-TSL) with encapsulated fluorescent dye carboxyfluorescein, anticancer drug doxorubicin or magnetic resonance contrast agent gadodiamide. Extrusion was performed with polycarbonate filters of distinct pore size to obtain TSL with different diameters (50 to 200 nm). Phase transition temperature (T-m) of the bilayer forming phospholipids was not influenced by vesicle size in the tested range. However, vesicle size had a major impact on in vitro content release properties of TSL in the investigated temperature range between 30 and 45 degrees C. Generally, vesicle size was inversely related to content release properties with increased content release rates for decreased vesicle sizes. Size dependency of content release properties varied between all tested formulations and DPPG(2)-TSL were generally less affected by size changes in the range of 100 to 150 nm as compared to PEG/Lyso-TSL. Independent from gadodiamide release, vesicle size influenced the signal intensity of DPPG(2)-TSL also at temperatures below T-m due to improved water exchange for smaller vesicles. Liposomes around 100 nm in size are routinely used in vivo, hence a quality control for TSL preparations is required prior to use. Even small changes in size or a wider size distribution might affect stability and release properties and thus yield in decreased efficacy or unwanted side effects of drug loaded TSL during in vivo applications.
AU  - Hossann, M.
AU  - Wang, T.
AU  - Wiggenhorn, M.*
AU  - Schmidt, R.*
AU  - Zengerle, A.*
AU  - Winter, G.*
AU  - Eibl, H.*
AU  - Peller, M.*
AU  - Reiser, M.*
AU  - Issels, R.D.
AU  - Lindner, L.H.
C1  - 5029
C2  - 27833
SP  - 436-443
TI  - Size of thermosensitive liposomes influences content release.
JO  - J. Control. Release
VL  - 147
IS  - 3
PB  - Elsevier Science
PY  - 2010
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - Liposomes are potent nanocarriers to deliver chemotherapeutic drugs to tumors. However, the inefficient drug release hinders their application. Thermosensitive liposomes (TSL) can release drugs upon heat. This study aims to identify the optimum 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-PEG(2000) (DSPE-PEG(2000)) concentration in stealth TSL to improve content release efficiency under mild hyperthermia (HT). TSL were prepared with DSPE-PEG2000 from 1 to 10 mol%, around 80 nm in size. Quenched carboxyfluorescein (CF) in aqueous phase represented encapsulated drugs. In vitro temperature/time-dependent CF release and TSL stability in serum were quantified by fluorometry. In vivo CF release in dorsal skin flap window chamber models implanted with human BLM melanoma was captured by confocal microscopy. In vitro heat triggered CF release increased with increasing DSPE-PEG2000 density. However, 6 mol% and higher DSPE-PEG2000 caused CF leakage at physiological temperature. TSL with 5 mol% DSPE-PEG2000 were stable at 37 degrees C. while released 60% CF in 1 min and almost 100% CF in 1 h at 42 degrees C. In vivo optical intravital imaging showed immediate massive CF release above 41 degrees C. In conclusion, incorporation of 5 mol% DSPE-PEG(2000) optimized stealth TSL content release triggered by HT.
AU  - Li, L.*
AU  - ten Hagen, T.L.M.*
AU  - Schipper, D.*
AU  - Wijnberg, T.M.*
AU  - van Rhoon, G.C.*
AU  - Eggermont, A.M.M.*
AU  - Lindner, L.H.
AU  - Koning, G.A.*
C1  - 4993
C2  - 27903
CY  - Amsterdam
SP  - 274-279
TI  - Triggered content release from optimized stealth thermosensitive liposomes using mild hyperthermia.
JO  - J. Control. Release
VL  - 143
IS  - 2
PB  - Elsevier Sci. BV
PY  - 2010
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - Lysolipid-based thermosensitive liposomes have been successfully introduced as efficient drug delivery system with fast drug release upon heat treatment. Hexadecylphosphocholine (HePC) is structurally related to 1-palmitoyl-2-lyso-sn-glycero-3-phosphocholine (P-lyso-PC) but chemically and metabolically more stable, thereby offering strong antineoplastic, antiprotozoal and antifungal activity. We investigated the properties of HePC in low temperature sensitive (LTSL) and high temperature sensitive liposomes (HTSL) based on 1,2-dipalmitoyl-sn-glycero-3-phosphoglyceroglycerol (DPPGOG). Therefore liposomes composed of DPPC/DSPC=8:2 (molar ratio), DPPC/DSPC/DPPGOG=5:2:3, HePC/DPPC/DSPC/DPPGOG=1:4:2:3, HePC/DSPC/DPPGOG=1:6:3 and P-lyso-PC/DPPC/DSPC/DPPGOG=1:4:2:3 were prepared by the lipid film hydration and extrusion method and compared with regard to stability at 37 degrees C and the release kinetics under heating conditions (38 degrees C-45 degrees C) in the presence of fetal calf serum. Each formulation was characterized for size distribution, zeta-potential, encapsulation efficiency and phase transition temperature (T(m)). The influence of heat on the cytotoxic activity of HePC in TSL was investigated using the WST-1 assay in BFS-1 fibrosarcoma and C6 glioma cells for the low (HePC-LTSL, T(m)=42.9 degrees C) and the high (HePC-HTSL, T(m)=48.5 degrees C) temperature sensitive formulations and compared to micellar HePC or plain TSL. The cellular HePC uptake after 15 min incubation at 37 degrees C or 42 degrees C was determined by liquid chromatography tandem-mass spectrometry (LC-MS/MS). As expected, HePC increases the release rate of TSL similar to lysolipid. The cytotoxicity of HePC in TSL was heat inducible and stronger than the one induced by micellar HePC which did not respond to heat. A possible explanation for this raise in cytotoxicity of HePC in TSL is the increased cellular transfer of HePC under heating conditions demonstrated by LC-MS/MS.
AU  - Lindner, L.H.*
AU  - Hossann, M.*
AU  - Vogeser, M.*
AU  - Teichert, N.*
AU  - Wachholz, K.*
AU  - Eibl, H.*
AU  - Hiddemann, W.*
AU  - Issels, R.D.
C1  - 2880
C2  - 25215
SP  - 112-120
TI  - Dual role of hexadecylphosphocholine (miltefosine) in thermosensitive liposomes: Active ingredient and mediator of drug release.
JO  - J. Control. Release
VL  - 125
IS  - 2
PB  - Elsevier
PY  - 2008
SN  - 0168-3659
ER  - 

TY  - JOUR
AU  - Lindner, L.H.
AU  - Brock, R.*
AU  - Arndt-Jovin, D.*
AU  - Eibl, H.
C1  - 2394
C2  - 23483
SP  - 444-456
TI  - Structural variation of cationic lipids: Minimum requirement for improved oligonucleotide deliver into cells.
JO  - J. Control. Release
VL  - 110
PY  - 2006
SN  - 0168-3659
ER  - 

TY  - JOUR
AU  - Mair, P.
AU  - Bahadir, M.A.
AU  - Korte, F.
C1  - 42614
C2  - 36445
SP  - 293-295
TI  - Controlled release behaviour of polymeric pentachlorophenyl esters.
JO  - J. Control. Release
VL  - 5
IS  - 3
PY  - 1988
SN  - 0168-3659
ER  - 

TY  - JOUR
AB  - The usefulness of Ca alginates as matrix material for controlled release formulations was investigated with the herbicides monolinuron (1), desmetryn (2), chloridazon (3), atrazine (4), MCPB (5), simazine (6) and chloroxuron (7) as active ingredients. Release rates of these substances were measured from hydrated and dried gel beads. The results obtained indicate that release from both gel types corresponds to the water solubilities of the active ingredients. Sufficient retardation of herbicide release up to several months could be attained with the hydrated and dried Ca alginate formulations of 6 and 7 (water solubilities 5 and 3.7 ppm, respectively) and the dried formulations of 4 and 5 (water solubilities 70 and 44 ppm, respectively).
AU  - Pfister, G.
AU  - Bahadir, M.A.
AU  - Korte, F.
C1  - 41438
C2  - 36091
SP  - 229-233
TI  - Release characteristics of herbicides from Ca alginate gel formulations.
JO  - J. Control. Release
VL  - 3
IS  - 1-4
PY  - 1986
SN  - 0168-3659
ER  -