Every entry summarises what the study set out to test, what it found and why it changes how we design delivery systems. Browse research and reviews or search the collection.
Bispecific T-cell engagers (BiTEs) are promising but require large amounts of purified protein, have high manufacturing costs, poor in vivo stability, and short serum half-lives. mRNA delivery could enable continuous endogenous production of BiTEs, but efficient and safe delivery systems are needed. The study developed a novel ionizable lipid nanoparticle (LNP) for mRNA encoding B7H3×CD3 BiTE to achieve prolonged half-life and potent antitumor. LNP@GFP-mRNA showed transfection efficiency comparable to Lipofectamine 8000 in 293T, AML12, and LO2 cells; serum presence did not affect transfection. - After IV LNP@Luc-mRNA, strongest luciferase signal was in liver.
Annabelle Biscans, Socheata Ly, Nicholas Mchugh, David A. Cooper, Anastasia Khvorova
Lipid-conjugated siRNAs can reach extrahepatic tissues, but silencing efficacy remains lower than in liver largely because only ~1–2% of internalized siRNA escapes endosomes into the cytoplasm. Ionizable lipids enhance endosomal escape in lipid nanoparticles (LNPs), but direct covalent conjugation of an ionizable lipid to siRNA had not been investigated. DLin-MC3-DMA conjugation retained RISC activity in vitro: IC50 values were 322 pM (unconjugated), 365 pM (cholesterol), and 481 pM (DLin-MC3-DMA). - Endosomal escape was enhanced: DLin-MC3-DMA-siRNA increased Gal8+.
Paolo Morfino, Alberto Aimo, Vincenzo Castiglione, Carolina Galvez-Montón, Michele Emdin, Antoni Bayes-Genis
Cardiac fibrosis contributes to the pathogenesis of heart failure, myocardial infarction, and arrhythmias, but no primarily anti-fibrotic drug has been approved for cardiovascular disease. Many candidate anti-fibrotic strategies have shown promise in preclinical models yet failed to demonstrate clear clinical benefit. There is a need to summarize current and emerging therapeutic options and to evaluate a new approach: targeting cardiac. RAAS inhibitors: Lisinopril reduced collagen volume fraction (CVF) vs. hydrochlorothiazide; losartan reduced CVF and PICP; spironolactone/eplerenone reduced PICP/PIIINP and improved diastolic function in some trials. -.
mRNA is a promising cancer immunotherapy platform for vaccines, cytokines, costimulatory receptors, and therapeutic antibodies, but it is unstable, immunogenic, and poorly delivered in vivo. Safer and more efficient delivery systems are needed to improve mRNA stability, cellular uptake, endosomal escape, and tumor-site accumulation. PL1 LNPs delivering CD137 or OX40 mRNA to tumor-infiltrating T cells, combined with anti-OX40 antibody, showed more significant antitumor activity than anti-OX40 antibody alone in multiple tumor models. -.
mRNA is an attractive platform for cancer immunotherapy, but its instability, susceptibility to RNase degradation, and inefficient endosomal escape limit therapeutic applications. Lipid-based nanocarriers are non-viral vectors that can protect mRNA, improve transfection, and deliver it to intracellular compartments suitable for translation. Optimal pKa for ionizable lipids: 6.2–6.5 for intravenous mRNA delivery; 6.6–6.9 for intramuscular mRNA delivery. - Modifying lipid-to-mRNA ratio can shift lipoplex charge: anionic lipoplexes target spleen, cationic.
Paula M. Cevaal, Abdalla Ali, Ewa Czuba-Wojnilowicz, Jori Symons, Sharon R. Lewin, Christina Cortez-Jugo, Frank Caruso
T cells are attractive targets for immunotherapy, cancer, HIV, autoimmunity, and inflammation, but nanoparticle delivery to T cells remains a major technological challenge due to their nonphagocytic nature and multiple physiological barriers. There is a need for rational design principles for in vivo T cell-targeting nanoparticles. --- - Barriers: Only ~2–3% of all T cells are in blood; <5% of administered nanoparticles typically reach target tissue; nanoparticles <~6 nm are renally cleared; T cells are nonphagocytic with low endocytosis rates; slow endosomal acidification in primary T cells can reduce pH-dependent cargo release. - Size rules: For receptor-mediated endocytosis (RME), optimum nanoparticle diameter ~50 nm; <200 nm preferred; >10 nm needed to avoid renal clearance; 10–100 nm ideal for lymph node delivery; <100 nm promotes escape from mononuclear phagocyte system scavenging. - Targeting outcomes: CD3-targeted PBAE/polygluta
Dapeng Zhang, Elena N. Atochina-Vasserman, Devendra S. Maurya, Ning Huang, Qi Xiao, Nathan Ona, Matthew Liu, Hamna Shahnawaz, Houping Ni, Kyunghee Kim, Margaret M. Billingsley, Darrin J. Pochan, Michael J. Mitchell, Drew Weissman, Virgil Percec
Four-component lipid nanoparticles (LNPs) represent the leading non-viral vectors for mRNA delivery, but they have limitations including: (1) segregation of the neutral ionizable lipid as droplets in the LNP core, reducing transfection efficiency to ~1-2%; (2) the "PEG dilemma" where PEGylation increases circulation time but decreases cellular uptake and endosomal escape; and (3) instability at temperatures above -70°C. A one-component system. ### IAJD Libraries & DNP Formation | Parameter | Result | |---------------|------------| | Total IAJDs synthesized | 54 (6 libraries) | | In vitro active DNPs | 44/54 (81%) | | In vivo active DNPs | 31/54 (57%) | | DNPs.
Johan Karlsson, Stephanie Y. Tzeng, Shayan Hemmati, Kathryn M. Luly, Olivia Choi, Yuan Rui, David R. Wilson, Kristen L. Kozielski, Alfredo Quiñones-Hinojosa, Jordan J. Green
Systemic delivery of RNA therapeutics with polymer-based nanocarriers is limited by poor colloidal stability in blood and inefficient intracellular delivery of siRNA to the cytosol. There is a need for nanoparticles that remain stable extracellularly but rapidly release RNA intracellularly. Crosslinking: Molecular weight increased by 42.1% (Mn) and 27.7% (Mw); acrylate peak intensity decreased by 79.1% ± 0.3%. - Serum stability: XbNPs retained siRNA encapsulation in 50% serum; non-crosslinked formulations.
siRNA therapeutics are limited by poor cellular uptake, serum nuclease degradation, and inefficient endosomal/lysosomal escape. Chitosan is biocompatible and biodegradable but has low transfection efficiency, largely due to poor buffering capacity and weak endosomal escape. Histidine grafting was explored to add imidazole groups (pKa ~6) that enhance proton-sponge buffering and siRNA delivery. Synthesis: FT-IR showed amide C=O at 1640 cm⁻¹ and N–H bending shift from 1590 to 1522 cm⁻¹; histidine O–H at 3016 cm⁻¹ disappeared. XRD showed loss of histidine crystal peaks at 18.8° and 24.3°, and HGCS polymers were.
mRNA vaccines are promising but naked mRNA is fragile, susceptible to enzymatic degradation, poorly taken up by cells due to electrostatic repulsion, and can trigger innate immune responses. Self-assembly offers a versatile approach to prepare delivery vehicles with customizable properties. The review discusses design and self-assembly of mRNA vaccines, materials commonly used, physicochemical characteristics, routes of administration, and. BNT162b2: 95.0% efficacy in phase III (8 COVID-19 cases in vaccine group vs 162 in placebo); 94.6% efficacy including prior infection; ~52% efficacy between first and second dose. - mRNA-1273: 94.1% efficacy in phase.
RNA therapeutics—ASOs, siRNAs, miRNAs, mRNAs, and CRISPR-Cas9 sgRNAs—are limited by nuclease degradation, large size, and negative charge. Ionizable lipids are the key LNP component that condenses RNA, enables endosomal escape, and reduces toxicity. Since 2008, many ionizable lipids have been created, but the field lacks systematic categorization to guide next-generation design. MC3 is used in the FDA-approved siRNA drug Onpattro (patisiran) for hereditary transthyretin amyloidosis. - Optimized C12-200 formulation increased mRNA expression 7-fold vs standard formulation. - 7C1 achieved ~80%.
Schlich M, Palomba R, Costabile G, Mizrahy S, Pannuzzo M, Peer D, Decuzzi P
Endosomal escape remains the major intracellular barrier for RNA therapeutics. Only a small fraction of RNA delivered by ionizable lipid nanoparticles (LNPs) reaches the cytosol, where siRNA, miRNA, mRNA, and CRISPR components must act. A deeper mechanistic understanding is needed to design next-generation LNPs with improved cytosolic delivery. Only 1–2% of siRNA delivered by MC3-LNPs was visualized in the cytosol in one key study; another estimated ~3.5% cytosolic release. - Endosomal escape occurs in a narrow time window from a hybrid early/late endosome.
Likely Citation: Swingle Kl, Hamilton Ag, Mitchell Mj
mRNA is degraded by nucleases and cannot easily cross cell membranes because of its large size and negative charge. Delivery therefore requires encapsulation in vehicles such as lipid nanoparticles (LNPs) to enable protein replacement, vaccines, and gene-editing applications. Onpattro was the first FDA-approved LNP-nucleic acid therapeutic, for polyneuropathy caused by transthyretin amyloidosis. - Pfizer-BioNTech and Moderna mRNA-LNP COVID-19 vaccines received FDA emergency use authorization.
mRNA has therapeutic potential for vaccines, protein replacement, cancer immunotherapy, cellular reprogramming, and genome editing, but it requires safe, effective, and stable delivery systems to protect it from degradation and enable cellular uptake and mRNA release. Lipid nanoparticles have entered the clinic for mRNA delivery, most notably in COVID-19 mRNA vaccines. COVID-19 mRNA vaccines mRNA-1273 and BNT162b2 showed ~95% efficacy in phase III trials and use ionizable LNPs (SM-102 and ALC-0315, respectively). - Influenza mRNA-1440: 100 µg dose induced 78.3% HAI and 87.0% MN.
mRNA therapeutics are limited by innate immune activation, rapid RNase degradation, and inefficient delivery to target organs. Although LNPs are the only clinically approved RNA therapeutic carriers, most systemically delivered LNPs accumulate in the liver, so organ-specific delivery remains a major barrier for protein replacement, cancer immunotherapy, and gene editing. LNPs are the only RNA therapeutic carriers approved for clinical use at the time of the review. - PEG content from 1% to 5% produces LNPs approximately 100 nm to 20 nm in size; 0.5% PEG gave highest subretinal.
Small-sized lipid nanoparticles (LNPs) are attractive for tissue penetration but often lose potency because lipid components diffuse out and serum proteins adsorb onto poorly packed surfaces. The study asked how the hydrophobic scaffold structure of pH-sensitive cationic lipids affects small-LNP stability, lipid miscibility, endosomal escape, and siRNA delivery. CL15H6-LNPs with 3 mol% PEG-DMG induced clear gene silencing (IC₅₀ ≈ 20 nM siRNA), whereas CL15A6-LNPs failed; cellular uptake of CL15H6-LNPs was about 2-fold higher. - Replacing cholesterol with ESM produced smaller.
Siddharth Patel, N. Ashwanikumar, Ema Robinson, Yan Xia, Cosmin Mihai, Joseph P. Griffith Iii, Shangguo Hou, Adam A. Esposito, Tatiana Ketova, Kevin Welsher, John L. Joyal, Örn Almarsson, Gaurav Sahay
Endosomal sequestration of lipid-based nanoparticles (LNPs) remains a formidable barrier to delivery, with only <2% of LNPs reaching the cytosol. The role of cholesterol structure in LNP-mediated mRNA delivery and endosomal escape was poorly understood. There is a need to decode the structural characteristics of cholesterol that are crucial for efficient intracellular delivery and improved gene transfection. Screening: β-sitosterol LNPs (eLNPs) showed up to 211-fold improvement in transfection vs cholesterol LNPs, with comparable size (~100 nm) and encapsulation (>90%). Group I (Vitamin D analogs) and Group III (5th ring.
CAR-T cell therapy is limited by complex manufacturing, viral vector use, high cost, and severe toxicities. A nonviral, transient CAR modification approach using self-assembled nanoparticles could provide a simpler, safer, and potentially broadly applicable alternative for T-cell engineering. Formulation screening: pDNA@SNP G1/800 gave the highest luciferase expression in Jurkat cells. Its activity was not significantly different from pDNA@SNP G1/2000 but was higher than other formulations, including up to.
ACS Biomaterials Science & Engineering (as indicated in the supplied file header; exact volume/pages and DOI were not in2020ResearchNon-viral Gene Delivery
Denis Routkevitch, Deepti Sudhakar, Marranne Conge, Mahita Varanasi, Stephany Y. Tzeng, David R. Wilson, Jordan J. Green
The mechanism by which cationic polymers with titratable amines mediate endosomal escape and cytosolic delivery of nucleic acids remains poorly understood. Buffering capacity alone has often failed to predict transfection efficacy, so the study examines whether the effective pKa of poly(beta-amino ester)s (PBAEs) governs cytosolic delivery and transfection. Transfection efficacy: PBAEs achieved up to 99% in HEK293T, 65% in B16-F10, and 90% in GB319 cells, with high viability. - Effective pKa: PBAE 746 = 6.16, PBAE 446 = 6.95, PBAE 447 = 7.15. PEI showed broad buffering.
ACS Biomaterials Science & Engineering (as indicated in the file header; exact volume/pages and DOI were not included in2020ResearchNon-viral Gene Delivery
Denis Routkevitch, Deepti Sudhakar, Marranne Conge, Mahita Varanasi, Stephany Y. Tzeng, David R. Wilson, Jordan J. Green
The mechanism by which cationic polymers with titratable amines mediate endosomal escape and cytosolic delivery of nucleic acids remains poorly understood. Buffering capacity alone has often failed to predict transfection efficacy, so this study examines whether the effective pKa of poly(beta-amino ester)s (PBAEs) governs cytosolic delivery and transfection. Transfection efficacy: PBAEs achieved up to 99% in HEK293T, 65% in B16-F10, and 90% in GB319 cells, with high viability. - Effective pKa: PBAE 746 = 6.16, PBAE 446 = 6.95, PBAE 447 = 7.15. PEI showed broad buffering.
mRNA is a flexible and potentially safer cancer immunotherapy platform, but its clinical use has been limited by extracellular instability, poor cellular uptake, and inefficient endosomal escape. Lipid nanoparticles have become the most advanced non-viral delivery system for mRNA, enabling therapeutic vaccines, antibody expression, and CAR T-cell engineering. Only 1–2% of LNPs are estimated to escape the endosomal pathway before lysosomal degradation; endosomal escape remains a major bottleneck. - Optimal ionizable lipid pKa for transfection is 6.2–6.5; MC3 has a pKa of.
Liu C, Zhang L, Dong N, Zhang W, Chen X, Gao R, Sun H.
Cationic liposomes (CLs) are promising non-viral gene-delivery vectors, but their clinical use in cancer gene therapy is limited by extracellular barriers (opsonization, RES clearance, poor tumor penetration) and intracellular barriers (endosomal/lysosomal entrapment, restricted cytoplasmic/nuclear transport). The review focuses on these barriers and how lipid composition and surface modification can be tailored to improve transfection. CLs face opsonization, RES clearance, poor tumor penetration, endosomal/lysosomal entrapment, and restricted nuclear diffusion. - Protein corona alters CL fate: DOTAP-rich liposomes preferentially bind vitronectin;.
Gene therapy is limited by the fragile nature of therapeutic DNA/RNA and by safety concerns with viral vectors. Non-viral polymeric vectors are attractive, but conventional cationic polymers such as PEI, PDMAEMA, and PLL are often non-degradable, causing accumulation, cytotoxicity, and poor gene unpacking. This review addresses the need for biodegradable polymeric vectors that maintain transfection efficiency while improving biocompatibility and. PHP: Degraded to half its original molecular weight in <2 h; complete degradation in about 3 months; transfection efficiency comparable to PLL and not significantly affected by serum proteins. - PAGA: Polyplexes showed.
Endosomal escape remains a major rate-limiting step for siRNA delivery. The structure–activity relationships (SAR) of pH-sensitive cationic lipids were incompletely understood, limiting rational design of lipid nanoparticles (LNPs) for efficient in vivo siRNA delivery to hepatocytes. Hydrophilic head group structure strongly affected apparent LNP pKa (range ~4.5–8.2); clogP of the head group correlated with apparent pKa. Optimal in vivo FVII silencing occurred at pKa ~6.3. - Hydrophobic tail.
