The Effect of Cholesterol Content on the Adjuvant Activity of Nucleic-Acid-Free Lipid Nanoparticles.

RNA vaccines are applicable to the treatment of various infectious diseases via the inducement of robust immune responses against target antigens by expressing antigen proteins in the human body. The delivery of messenger RNA by lipid nanoparticles (LNPs) has become a versatile drug delivery system used in the administration of RNA vaccines. LNPs are widely considered to possess adjuvant activity that induces a strong immune response. However, the properties of LNPs that contribute to their adjuvant activity continue to require clarification. To characterize the relationships between the lipid composition, particle morphology, and adjuvant activity of LNPs, the nanostructures of LNPs and their antibody production were evaluated. To simply compare the adjuvant activity of LNPs, empty LNPs were subcutaneously injected with recombinant proteins. Consistent with previous research, the presence of ionizable lipids was one of the determinant factors. Adjuvant activity was induced when a tiny cholesterol assembly (cholesterol-induced phase, ChiP) was formed according to the amount of cholesterol present. Moreover, adjuvant activity was diminished when the content of cholesterol was excessive. Thus, it is plausible that an intermediate structure of cholesterol (not in a crystalline-like state) in an intra-particle space could be closely related to the immunogenicity of LNPs.

Antiseizure medication treatment outcomes in new-onset pediatric epilepsy.

BACKGROUND: Antiseizure medications (ASMs) are the primary treatment for epilepsy; however, some prospective cohort studies in adults suggested that the efficacy of the third and subsequent ASM treatments are poor. Thus, we aimed to assess the outcomes of ASM treatment in new-onset pediatric epilepsy. METHODS: We retrospectively studied 281 pediatric patients diagnosed with epilepsy, in which the first ASM was prescribed between July, 2015, and June, 2020, at Hiroshima City Funairi Citizens Hospital. We reviewed their clinical profiles and seizure outcomes at the end of the study in August, 2022. Seizure freedom was defined as having no seizures for the previous 12 months or longer. RESULTS: Age at the onset of epilepsy ranged from 22 days to 186 months (mean: 84 months). The most frequent classifications of the types and syndromes of epilepsy were focal epilepsy (n = 151, 53.7%), followed by generalized epilepsy (n = 30, 10.7%), and self-limited epilepsy with centrotemporal spikes (n = 20, 7.1%). During the first ASM regimen, 183 out of the 281 (65.1%) patients became seizure free. During the second ASM regimen, 47 out of the 92 (51.1%) patients became seizure free. Only 15 out of the 40 (37.5%) patients who tried the third and subsequent ASM regimen became seizure free, while none became seizure free after the sixth and subsequent ASM regimen. CONCLUSIONS: The efficacy of ASM treatment after the third and subsequent regimen was poor in children, as well as in adults. It is important to reconsider whether there are indications for treatments other than ASM.

Ready-to-Use-Type Lyophilized Lipid Nanoparticle Formulation for the Postencapsulation of Messenger RNA.

Based on the clinical success of an in vitro transcribed mRNA (IVT-mRNA) that is encapsulated in lipid nanoparticles (mRNA-LNPs), there is a growing demand by researchers to test whether their own biological findings might be applicable for use in mRNA-based therapeutics. However, the equipment and/or know-how required for manufacturing such nanoparticles is often inaccessible. To encourage more innovation in mRNA therapeutics, a simple method for preparing mRNA-LNPs is prerequisite. In this study, we report on a method for encapsulating IVT-mRNA into LNPs by rehydrating a Ready-to-Use empty freeze-dried LNP (LNPs(RtoU)) formulation with IVT-mRNA solution followed by heating. The resulting mRNA-LNPs(RtoU) had a similar intraparticle structure compared to the mRNA-LNPs prepared by conventional microfluidic mixing. In vivo genome editing, a promising application of these types of mRNA-LNPs, was accomplished using the LNPs(RtoU) containing co-encapsulated Cas9-mRNA and a small guide RNA.

Preclinical safety and efficacy of in situ REIC/Dkk-3 gene therapy for prostate cancer.

The preclinical safety and therapeutic efficacy of adenoviral vectors that express the REIC/Dkk-3 tumor suppressor gene (Ad-REIC) was examined for use in prostate cancer gene therapy. The Ad-human (h) and mouse (m) REIC were previously demonstrated to induce strong anti-cancer effects in vitro and in vivo, and we herein report the results of two in vivo studies. First, intra-tumor Ad-hREIC administration was examined for toxicity and therapeutic effects in a subcutaneous tumor model using the PC3 prostate cancer cell line. Second, intra-prostatic Ad-mREIC administration was tested for toxicity in normal mice. The whole-body and spleen weights, hematological and serum chemistry parameters, and histological evaluation of tissues from throughout the body were analyzed. Both experiments indicated that there was no significant difference in the examined parameters between the Ad-REIC-treated group and the control (PBS- or Ad-LacZ-treated) group. In the in vitro analysis using PC3 cells, a significant apoptotic effect was observed after Ad-hREIC treatment. Confirming this observation, the robust anti-tumor efficacy of Ad-hREIC was demonstrated in the in vivo subcutaneous prostate cancer model. Based on the results of these preclinical experiments, we consider the adenovirus-mediated REIC/Dkk-3 in situ gene therapy to be safe and useful for the clinical treatment of prostate cancer.