Biology subjects

Martinez-Olivan, J.

Publications and source records attributed to Martinez-Olivan, J..

4 recordsLinked to original sources

bioRxiv2025

Enhancement of mRNA translation efficiency through 5'-UTR engineering

The rapid progress of mRNA therapeutics has underscored a persistent challenge: achieving high protein expression at low dose. The 5 untranslated region (5-UTR) is a key regulator of translation initiation efficiency, prompting the question of whether a simple and portable modification could enhance expression across diverse designs. Here, we systematically engineered short repeats of the Kozak "core" motif (5-GCCACC-3) immediately upstream of the start codon and evaluated constructs incorporated into two widely used human UTRs (APO and HBB) in HeLa and HEK293T cells. Translation enhancement displayed a non-monotonic dependence on the number of Kozak repeats, with three repetitions consistently outperforming the native sequence and any other configuration. In mice, intramuscular lipid nanoparticle delivery of the three-copy design increased luciferase expression by [~]4-fold relative to the wild-type context and by up to [~]23-fold compared to a licensed vaccine UTR benchmark, providing clear in vivo relevance. These findings demonstrate that fine-tuning AUG-proximal Kozak elements constitutes a broadly applicable, UTR-independent strategy to enhance translation efficiency, offering a simple yet powerful principle for dose-sparing mRNA design in therapeutic applications.

bioengineering↗

bioRxiv2025

CertPrime: a new oligonucleotide design tool for gene synthesis

The design of oligonucleotides with uniform hybridisation temperatures is essential for successful gene synthesis. However, current computational tools for oligonucleotide design face significant limitations, including difficulties in processing long DNA sequences, poor adaptability to specific experimen- tal conditions, limited control over oligonucleotide length, and challenges in minimising spurious dimer formation. To address these issues, we devel- oped CertPrime, an innovative tool designed for scalable and efficient han- dling of long DNA sequences. CertPrime enables precise customisation of experimental parameters, provides flexibility to limit the maximum oligonu- cleotide length, and generates designs with reduced deviations in melting temperatures across overlapping regions compared to existing tools. We experimentally compared CertPrime designs with benchmark design meth- ods for a complex DNA sequence and found that CertPrime design led to more efficient gene assembly, significantly reducing the occurrence of non- specific bands. These results make CertPrime a powerful and versatile tool for oligonucleotide design in gene synthesis applications. HighlightsO_LICertPrime improves oligonucleotide design by minimising melting-temperature deviations and spurious dimer formation. C_LIO_LIThe new tool enhances gene-synthesis efficiency, allowing a precise con- trol over oligonucleotide lengths and experimental parameters. C_LIO_LICertprime is a scalable tool capable of designing over 99% of the human genome with optimized sequence assembly C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=79 SRC="FIGDIR/small/650686v1_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@2032aaorg.highwire.dtl.DTLVardef@1de509borg.highwire.dtl.DTLVardef@7e2148org.highwire.dtl.DTLVardef@bb3dd2_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

bioRxiv2024

A complete approach for circRNA therapeutics from purification to lyophilized delivery using novel ionizable lipids

Circular RNA (circRNA) has gained significant attention as a potential therapeutic tool due to its remarkable stability and resistance to degradation by exonucleases. However, scalable and efficient methods for purification and delivery remain critical challenges that must be addressed. In this study, we developed and evaluated an optimized affinity chromatography method using Oligo(dT) columns for the purification of circRNA, achieving high yield and purity comparing with high-performance liquid chromatography. Additionally, we investigated the in vivo efficacy of circRNA-Oligo(dT) encapsulated in lipid nanoparticles (LNPs) formulated with emerging STAAR ionizable lipids, including CP-LC-0867 and CP-LC-0729. Our results showed that LNPs formulated with CP-LC-0867 consistently produced higher protein expression compared to SM-102, with sustained luciferase activity observed over a 14-day period. Furthermore, we assessed the lyophilization potential of LNP-circRNA-Oligo(dT) using CP-LC-0729 to extend shelf life and eliminate the need for ultra-low temperature storage. Remarkably, the lyophilized LNPs exhibited no significant differences in protein expression compared to their non-lyophilized counterparts, demonstrating that lyophilization is a viable strategy for extending the storage and transport of circRNA therapies. These findings underscore the potential of optimized new ionizable lipids, improved purification strategies, and lyophilization techniques to enhance the scalability, stability, and practical application of circRNA therapies. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=91 SRC="FIGDIR/small/620632v1_ufig1.gif" ALT="Figure 1"> View larger version (20K): org.highwire.dtl.DTLVardef@8bb7eeorg.highwire.dtl.DTLVardef@d8a1eeorg.highwire.dtl.DTLVardef@6f359forg.highwire.dtl.DTLVardef@1295d05_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2024

Multicomponent Thiolactone-Based Ionizable Lipid Screening Platform for an Efficient and Tunable mRNA Delivery to the Lungs

Ionizable lipids are an essential component of lipid nanoparticles (LNPs) for an efficient mRNA delivery. However, optimizing their chemical structures for high protein expression, efficient endosomal escape, and selective organ targeting remains challenging due to complex structure-activity relationships and multistep synthesis. In this study, we introduce a rapid, high-throughput platform for screening ionizable lipids using a two-step, scalable synthesis involving a one-pot 3-component click-like reaction. This method, herein known as the STAAR approach, standing for Sequential Thiolactone Amine Acrylate Reaction, allowed for the combinatorial synthesis and in vivo screening of 91 novel lipids, followed by a structure-activity study. This led to the development of CP-LC-0729, an ionizable lipid that significantly surpasses the benchmark in protein expression while showing no in vivo toxicity. Additionally, the STAAR lipid platform was further validated by incorporating a one-step strategy to yield a permanently cationic lipid which was tested following a fifth-lipid formulation strategy. The in vivo results showed a highly selective lung delivery with a 32-fold increase in protein expression, outperforming current endogenous targeting strategies. All these findings underscore the potential of lipid CP-LC-0729 and the STAAR lipid platform in advancing the efficiency and specificity of mRNA delivery systems, while also advancing the development of new ionizable lipids.

biochemistry↗