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.

Investigation of eligibility for adjuvant therapy from real-world data of patients with urothelial carcinoma undergoing radical cystectomy and radical nephroureterectomy.

OBJECTIVE: Adjuvant nivolumab prolonged disease-free survival compared with placebo in patients at high risk of recurrence following radical cystectomy or radical nephroureterectomy in the CheckMate 274 trial. However, the ideal eligibility criteria for adjuvant therapy in real-world clinical practice remain controversial. METHODS: We retrospectively analyzed clinical data of 409 patients who underwent radical cystectomy (n = 252) or radical nephroureterectomy (n = 157) and validated the risk of recurrence based on the classification used in the CheckMate 274 trial. We also investigated the impact of perioperative chemotherapy, lymph node dissection and pathological factors on prognosis. RESULTS: The median follow-up time was 37.5 and 32.1 months in bladder cancer and upper tract urothelial carcinoma, respectively. Among the high-risk patients based on CheckMate 274 trial, disease-free survival was considerably shorter for bladder cancer and upper tract urothelial carcinoma patients than for low-risk patients (hazard ratios: 4.132 and 7.101, respectively). The prevalence of adjuvant chemotherapy in high-risk patients was low (24 and 38% for bladder cancer and upper tract urothelial carcinoma, respectively). The extent of lymph node dissection in bladder cancer and presence of lymph node dissection in upper tract urothelial carcinoma did not affect prognosis. Cox proportional multivariate analysis revealed CheckMate 274-high-risk as a poor prognostic factor in bladder cancer and upper tract urothelial carcinoma. CONCLUSIONS: This study validated the risk classification for recurrence following radical cystectomy and radical nephroureterectomy using the CheckMate 274 criteria in real-world practice. Further research would help assess the degree of benefit obtained from adjuvant nivolumab.

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.