Doxorubicin-liposomes loaded microbubbles for ultrasound-triggered doxorubicin delivery

International audienceDoxorubicin (Dox) is a potent chemotherapeutic whose severe side effects limit its clinical efficacy. Microbubble-assisted ultrasound has become a promising strategy for non-invasive local drug delivery to increase the drug concentration locally and to reduce systemic side effects. The aim of this study is to evaluate the effectiveness of administration of Dox-liposomes loaded on MB combined with ultrasound in human glioblastoma cells. Experiments were carried out with free Dox or Dox-loaded MBs on a cell suspension of U-87MG cells. Ultrasound waves were transmitted at 1MHz frequency with a pulse repetition period of 100µs, 40 cycles per pulse and for 30s. Cell viability was evaluated by Trypan blue assay 24h and 48h later. Using Dox alone, the cell viability was 63±3% and 26±2% at 24h and 48h later, respectively. The combination of ultrasound at 600 kPa and Dox-loaded MBs induced a 2.5-fold decrease of cell viability compared to the incubation of Dox-loaded MBs alone at 24h and 48h after treatment, respectively. At 24h, this combination was 3 times more efficient than the doxorubicin treatment alone. The conclusions drawn from this study show the potential of this strategy for a controlled, efficient, and safe drug delivery. Project funded by the EU Project SONODRUGS (NMP4-LA-2008-213706)

Optical characterization of individual liposome-loaded microbubbles

Newly developed liposome-loaded (LPS) microbubbles are characterized by comparing their oscillating response with standard phospholipid-coated (bare) microbubbles using the ultra-high speed imaging (Brandaris 128) camera. A study of the shell properties indicate nearly the same shell elasticity and a higher shell viscosity for LPS bubbles than for bare bubbles. A frequency and pressure-dependent bubble acoustical behavior study shows a higher threshold for the initiation of bubble vibrations for LPS bubbles. In addition, an “expansion-only” behavior was observed for up to 69% of the investigated LPS bubbles which mostly occurred at lower acoustic pressures (≤30 kPa). Liposome attachment stability were studied using fluorescence imaging. The internal relationship among morphological structure, shell properties and ultrasonic behavior of LPS bubbles by optical characterization facilitate preclinical study and clinical application of LPS bubbles in ultrasound triggered drug delivery system.Newly developed liposome-loaded (LPS) microbubbles are characterized by comparing their oscillating response with standard phospholipid-coated (bare) microbubbles using the ultra-high speed imaging (Brandaris 128) camera. A study of the shell properties indicate nearly the same shell elasticity and a higher shell viscosity for LPS bubbles than for bare bubbles. A frequency and pressure-dependent bubble acoustical behavior study shows a higher threshold for the initiation of bubble vibrations for LPS bubbles. In addition, an “expansion-only” behavior was observed for up to 69% of the investigated LPS bubbles which mostly occurred at lower acoustic pressures (≤30 kPa). Liposome attachment stability were studied using fluorescence imaging. The internal relationship among morphological structure, shell properties and ultrasonic behavior of LPS bubbles by optical characterization facilitate preclinical study and clinical application of LPS bubbles in ultrasound triggered drug delivery system

Focal delivery of AAV2/1-transgenes into the rat brain by localized ultrasound-induced BBB opening

Delivery of drugs and macromolecules to the central nervous system (CNS) is hindered by the blood-brain barrier (BBB). Several approaches have been used to overcome this hindrance to facilitate the treatment of various CNS diseases. We now present results showing that chimeric adeno-associated virus 2/1 (AAV2/1) particles containing the coding region for the LacZ gene are efficiently delivered into the rat brain upon intravenous (IV) administration after BBB opening by focused ultrasound in the presence of vascular acoustic resonators. We show that the transgene is correctly and efficiently expressed in cells located in the neighborhood of the insonated focus, especially in the vicinity of small vessels and capillaries. Histochemical LacZ staining allows the identification of large amounts of cells expressing the enzymatically active protein. Using double immunofluorescence (IF) with antibodies against tubulinIII and bacterial LacZ, we identified these cells to be mostly neurons. A small proportion of the transduced cells was recognized as glial cells, reacting positive in the IF with antibodies against astrocytic markers. These results demonstrate that our approach allows a very specific, localized, and efficient expression of intravenously administered transgenes in the brain of rats upon ultrasound-induced BBB opening

Immunogenicity of a bivalent BA.1 COVID-19 booster vaccine in people with HIV in the Netherlands

OBJECTIVE: We evaluated the immunogenicity of a bivalent BA.1 COVID-19 booster vaccine in people with HIV (PWH).DESIGN: Prospective observational cohort study.METHODS: PWH aged ≥45 years received Wuhan-BA.1 mRNA-1273.214 and those &lt; 45 years Wuhan-BA.1 BNT162b2. Participants were propensity score-matched 1:2 to people without HIV (non-PWH) by age, primary vaccine platform (mRNA-based or vector-based), number of prior COVID-19 boosters and SARS-CoV-2 infections, and spike (S1)-specific antibodies on the day of booster administration. The primary endpoint was the geometric mean ratio (GMR) of ancestral S1-specific antibodies from day 0 to 28 in PWH compared to non-PWH. Secondary endpoints included humoral responses, T-cell responses, and cytokine responses up to 180 days post-vaccination.RESULTS:Forty PWH received mRNA-1273.214 (N = 35) or BNT162b2 (N = 5) following mRNA-based (N = 29) or vector-based (N = 11) primary vaccination. PWH were predominantly male (87% vs 26% of non-PWH) and median 57 years (interquartile range [IQR] 53-59). Their median CD4+ T-cell count was 775 (IQR 511-965) and the plasma HIV-RNA load was &lt; 50 copies/mL in 39/40. The GMR of S1-specific antibodies by 28 days post-vaccination was comparable between PWH (4.48, 95% confidence interval [CI] 3.24-6.19) and non-PWH (4.07, 95% CI 3.42-4.83). S1-specific antibody responses were comparable between PWH and non-PWH up to 180 days, and T-cell responses up to 90 days post-vaccination. IFN-γ, IL-2, and IL-4 cytokine concentrations increased 28 days post-vaccination in PWH.CONCLUSION: A bivalent BA.1 booster vaccine was immunogenic in well-treated PWH, eliciting comparable humoral responses to non-PWH. However, T-cell responses waned faster after 90 days in PWH compared to non-PWH.</p

Immunogenicity of an additional mRNA-1273 SARS-CoV-2 vaccination in people with HIV with hyporesponse after primary vaccination

Background:The COVIH study is a prospective coronavirus disease 2019 (COVID-19) vaccination study in 1154 people with HIV (PWH), of whom 14% showed reduced antibody levels after primary vaccination. We evaluated whether an additional vaccination boosts immune responses in these hyporesponders. Methods: The primary end point was the increase in antibodies 28 days after additional mRNA-1273 vaccination. Secondary end points included neutralizing antibodies, S-specific T-cell and B-cell responses, and reactogenicity. Results:Of the 66 participants, 40 previously received 2 doses ChAdOx1-S, 22 received 2 doses BNT162b2, and 4 received a single dose Ad26.COV2.S. The median age was 63 years (interquartile range [IQR], 60–66), 86% were male, and median CD4 + T-cell count was 650/μL (IQR, 423–941). The mean S1-specific antibody level increased from 35 binding antibody units (BAU)/ mL (95% confidence interval [CI], 24–46) to 4317 BAU/mL (95% CI, 3275–5360) (P &lt; .0001). Of all participants, 97% showed an adequate response and the 45 antibody-negative participants all seroconverted. A significant increase in the proportion of PWH with ancestral S-specific CD4 + T cells (P = .04) and S-specific B cells (P = .02) was observed. Conclusions:An additional mRNA-1273 vaccination induced a robust serological response in 97% of PWH with a hyporesponse after primary vaccination.</p

MINDS. Abundant water and varying C/O across the disk of Sz 98 as seen by JWST/MIRI

MIRI/MRS on board the JWST allows us to probe the inner regions of protoplanetary disks. Here we examine the disk around the classical T Tauri star Sz 98, which has an unusually large dust disk in the millimetre with a compact core. We focus on the H$_2$O emission through both its ro-vibrational and pure rotational emission. Furthermore, we compare our chemical findings with those obtained for the outer disk from Atacama Large Millimeter/submillimeter Array (ALMA) observations. In order to model the molecular features in the spectrum, the continuum was subtracted and LTE slab models were fitted. The spectrum was divided into different wavelength regions corresponding to H$_2$O lines of different excitation conditions, and the slab model fits were performed individually per region. We confidently detect CO, H$_2$O, OH, CO$_2$, and HCN in the emitting layers. The isotopologue H$^{18}_2$O is not detected. Additionally, no other organics, including C$_2$H$_2$, are detected. This indicates that the C/O ratio could be substantially below unity, in contrast with the outer disk. The H$_2$O emission traces a large radial disk surface region, as evidenced by the gradually changing excitation temperatures and emitting radii. The OH and CO$_2$ emission are relatively weak. It is likely that H$_2$O is not significantly photodissociated; either due to self-shielding against the stellar irradiation, or UV-shielding from small dust particles. The relative emitting strength of the different identified molecular features point towards UV-shielding of H$_2$O in the inner disk of Sz 98, with a thin layer of OH on top. The majority of the organic molecules are either hidden below the dust continuum, or not present. In general, the inferred composition points to a sub-solar C/O ratio (<0.5) in the inner disk, in contrast with the larger than unity C/O ratio in the gas in the outer disk found with ALMA.Comment: Submitted to A&A on May 25 2023. 18 pages, 11 figure