Posters and Poster Guidelines

Thank you for considering presenting your work as a poster at Aptamers 2024.


Digital poster preparation and submission 
  • Page size: Prepare your poster as you would normally do for printing. You can prepare your poster in sizes A1 or A0, as the page size is not important for digitally presented posters.
  • Naming your poster files: Name your poster files as follows: <your surname>-APT24-Poster.pdf | For example, for David Jones, name your file as Jones-APT24-Poster.pdf. DO NOT name your poster files as, e.g.,  Oxford-poster, Aptamers2024, Oxford-aptamers-poster. Such files will be automatically rejected.
  • Poster submission: All poster presenters, whether attending virtually or in-person, are required to submit a digital version of their poster. Submit your final poster as PDF (<5MB) via the link below no later than 12th March 2024. Late posters may not be included in the conference programme. Please DO NOT send your poster (or abstract) files by email. Please ensure you send us the very final version of your poster (as well as your poster abstract), as once published, it cannot be replaced. Posters will be made available via the secure conference documents page to the conference participants.

Before uploading your poster, you must make sure that you follow ALL of the instructions above!

 Upload Your Digital Poster

Poster presentation
  • Flash-talks (optional – TBC): Poster presenters will have the opportunity to introduce their poster in a short, 90 second flash presentation using 1-2 PowerPoint slides during their allocated break. If you are planning to give a flash-talk, please submit 1-2 PowerPoint slides, appropriately named to match your digital poster file (e.g., <your surname>-APT24-slides.pptx), along with your digital poster. The session chair will share your slides on your behalf during your presentation. Please check the website for your poster presentation schedule. Practice beforehand so that you can finish your presentation within your allocated time slot.
  • Flash-talk videos (optional): We are pleased to offer poster presenters the opportunity to prepare a short video presentation about their poster and send it before the conference. The videos will be made available on our partner YouTube channel, LPMHealthcare. Below is further information for sending your video presentation.
    • Give your presentation (no longer than 5 minutes) using Zoom or another platform of your choice.
    • Convert the video into a format compatible with YouTube (e.g., MP4).
    • Send your video to AptamersOxford@gmail.com using a file transfer program, such as MailBigFile or WeTransfer.
  • Hardcopy posters: If attending in-person, you may bring along a printed copy of your (maximum A1 size, portrait), to be displayed during the conference. Only A1-sized posters will be displayed. Your poster may be displayed on Day 1 or Day 2 only due to space constraints.
  • The participants can post their questions on Twitter at any time using the meeting hashtag #AptOx24, as well as the poster specific hashtag (given under each poster abstract) – do tag @AptamerSociety in your tweets.
  • Any further information about the poster presentations at this digital meeting will be available in the future.

Before uploading your poster and flash-talk slides, you must make sure that you follow ALL of the instructions above!

 Upload Your Digital Poster

Accepted poster abstracts (unedited)

(Presenters in Bold)

If your abstract has been accepted for presentation but it does not appear in the list below, please let us know as soon as possible by emailing AptamersOxford@gmail.com.


DNA aptamers to distinguish Dengue and Zika NS1 protein

Soma Banerjee1 and Marit Nilsen-Hamilton1,2

1 Aptalogic Inc, USA

2 Roy J Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, USA

The diseases caused by dengue viruses (DENV), mosquito-borne members of the family Flaviviridae,have emerged as the most important arthropod-borne viral diseases of humans. The frequency, geographicaldistribution, and severity of DENV epidemics have increased dramatically over the past decade. DENV isspread by mosquito species that also harbour Zika virus (ZIKV). Although these virusesare endemic in tropical countries, they have also been reported in the southern states of the USA and are likely to move northward as global climate change increases their range. Early symptoms of DENV infection overlap with symptoms caused by many other haemorrhagic viruses including ZIKV, Ebola and yellow fever. Cross reactivity and prolonged presence of virus specific antibodies bring challenges to serological tests in distinguishing ZIKV and DENV infections. This is a serious problem particularly in areas where DENV and ZIKV are endemic. As an alternate to antibodies, nucleic acid aptamers are emerging as a new generation of molecular recognition elements for diagnostics based on their synthetic nature, stability under a wide range of temperatures and amenability to different sensing platforms. Aptamers and antibodies often bind to different epitopes on a target protein, which can result in aptamers recognizing regions on an antigen that are not bound by antibodies and that therefore might be less likely to evolve rapidly as the virus avoids antibody detection. Therefore, we selected DNA aptamers that can specifically bind the DENV NS1 but not the Zika NS1 protein. Interestingly our studies show that the specificity exists only at NS1 protein concentrations higher than 250 nM. At lower concentrations the selected DNA aptamers bind both proteins and cannot distinguish DENV NS1 from ZIKV NS1. Understanding the molecular basis of this result is expected to reveal the structural features of Zika NS1 protein that alter aptamer binding in a concentration dependent manner.


Magnetic beads SELEX technology:  advancing aptamer selection towards personalized antibiotic treatment

Magdolna Casian1,2, Oana Hosu-Stancioiu1, Ioana Manea1, Dimas Suárez2, Natalia Díaz2, María Jesús Lobo Castañón2,3, Noemí de-los-Santos-Álvarez2,3, Cecilia Cristea1

1 Department of Analytical Chemistry, Faculty of Pharmacy, Iuliu Hațieganu University of Medicine and Pharmacy, 4 Pasteur Street, 400349, Cluj-Napoca, Romania

2 Departamento de Química Física y Analítica, Universidad de Oviedo, c/Julián Clavería 8, 33006 Oviedo, Spain

3 Instituto de Investigación Sanitaria del Principado de Asturias, Av. de Roma s/n, 33011, Oviedo, Spain

Glycopeptide antibiotics are the first-line treatment for severe infections, particularly methicillin-resistant Staphylococcus aureus. Vancomycin has a narrow therapeutic window, and it is rather difficult to ensure safe dose determination, reason why therapeutic drug monitoring is highly required. In the field of precision medicine, aptamers have emerged as an innovative class of biorecognition elements owing to their stable three-dimensional structure, high specificity, and versatility. This study presents the main strategy and results regarding the selection of a novel aptamer for vancomycin through SELEX technology. A total of 9 selection rounds were performed using magnetic beads, due to their good dispersion properties and quick responsiveness, facilitating a fast and effective separation process between the immobilized target and DNA sequences. To make the selection more stringent, negative- and counter-selection steps were introduced. The amplification yield and DNA purity were monitored by fluorimetry and gel electrophoresis. The evolution of the selection was assessed via UV-VIS-based enrichment assay, and round 7, showing the highest affinity towards vancomycin, was further cloned and sequenced. The affinity of the most promising aptamers was evaluated using surface plasmon resonance, obtaining dissociation constants in the nanomolar range. For a more comprehensive understanding of the aptamer–vancomycin interaction, docking analysis and molecular dynamics calculations were performed. Further steps envision the development of a portable electrochemical aptasensor for fast and specific quantification of vancomycin from clinical serum samples. This work was supported by a grant of Romanian Ministry of Education and Research PN-IV-P8-8.1-PRE-HE-ORG-2023-0076 contract no. 26 PHE/2022, Spanish Ministerio de Ciencia e Innovación Project PID2021-123183OB-100 MICIN/AEI/10.13039/501100011033/FEDER UE and Iuliu Hațieganu UMF internal grant no. 648/1/11.01.2024.


Aptamer-based system for Early-stage Pancreatic Cancer Exosome Enrichment and Diagnosis

Jingyu Cui 1, Lin Wang 1,2, Simon Chi-Chin Shiu 1, Andrew B Kinghorn 1, Julian A Tanner 1

1 School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China

2 Advanced Biomedical Instrumentation Centre, Hong Kong Science Park, Shatin, New Territories, Hong Kong SAR, China

Pancreatic cancer is one of the deadliest cancers, with most cases diagnosed late, leading to a median survival of less than five years. Early detection biomarkers are critical, and exosomes, small vesicles containing cellular materials, are potential non-invasive diagnostic tools. However, traditional exosome isolation methods like ultracentrifugation and chromatography are inefficient and can damage exosomes. Therefore, there’s a need for better methods. Aptamers, which are specific nucleic acids that bind their targets with high affinity, offer a promising solution. They are stable, non-immunogenic, and cost-effective, making them ideal for developing new exosome isolation techniques for pancreatic cancer diagnosis. In this work, we have developed a SELEX strategy target to intact exosomes, termed Exo-SELEX. We isolated exosomes from cell culture medium and subjected them to 12 rounds of Exo-SELEX. Given the similar characteristics of exosomes secreted by cancer cells, we identified a universal aptamer, Apt2, capable of recognizing exosomes. Among the sequence obtained, we optimized the length of Apt2; however, the original length demonstrated the best recognition performance. Consequently, our experiments focused on the full-length Apt2, we then conjugated Apt2 with magnetic beads to facilitate the gentle and effective isolation of exosomes from complex matrices such as cell culture media or serum samples, without the need for elaborate operations or equipment. The efficacy of the exosome enrichment process was verified through methods like Western blotting. For the specific identification of pancreatic cancer exosomes, we elected to measure certain miRNAs within the pulled-down exosomes, distinguishing between different cancers for the specific detection of pancreatic cancer. It is anticipated that this approach will offer novel insights for the isolation of exosomes and the specific detection of cancers.


DNA and Methylene-blue Modified Non-Natural DNA SELEX against Pancreatic Cancer Biomarkers

Weisi HE 1, Marcel HOLLENSTEIN 3, Julian Alexandar TANNER 1,2

1 School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China

2 Advanced Biomedical Instrumentation Centre, Hong Kong Science Park, Shatin, New Territories, Hong Kong SAR, China

3 Institut Pasteur, Université Paris Cité, CNRS UMR3523, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, 28, rue du Docteur Roux, 75724 Paris Cedex 15, France

Pancreatic cancer (PC) has a high mortality rate with poor prognosis. The poor prognosis is partially due to late detection of PC. Now in the market, blood testing for the pancreatic cancer glycan biomarker CA 19-9 uses 1116NS19.9 antibody. CA 19-9 is the only FDA approved biomarker for monitoring PC. Aptamers hold promise as an alternative to antibodies but targeting glycans with aptamers has been a challenge. Here, we report two aptamer SELEX to select out aptamers which could be used in a PC aptasensor. We report a natural DNA aptamer SELEX against asprosin, one of the early-stage pancreatic cancer biomarkers. We also report a methylene blue modified DNA aptamer SELEX against CA19-9. For the asprosin aptamer SELEX, we discovered three classes of asprosin aptamer sequence. Class I were A rich sequences, which contains over 50% of A in random region. Class II is AC rich sequences and Class III are diverse sequences. Ten asprosin aptamer candidates showed nanomolar level of binding to our expressed asprosin and eight candidates have high specificity in ELONA. Other characterization assays including electrochemical assays are ongoing. For the CA19-9 aptamer methylene-blue modified non-natural SELEX, we have synthesised the methylene blue modified nucleotide. Different conditions, including different polymerases, extension times and concentration of methylene blue modified nucleotides, have been tested to integrate the modified nucleotide into ssDNA library. Furthermore, the strategy of CA19-9 aptamer SELEX was developed and preliminary aptamers have been selected. In the longer term we aim to develop these aptamers into multiplexed aptasensors for pancreatic cancer.


Aptamer-based nanoplatform for the electrochemical detection of cortisol in biological samples

Maria-Bianca Irimes, Alexandra Pusta, Mihaela Tertis, Radu Oprean, Cecilia Cristea

Analytical Chemistry Department, Faculty of Pharmacy, Iuliu Hatieganu University of Medicine and Pharmacy, 4 Louis Pasteur St., Cluj-Napoca, Romania

Cortisol (COR), a glucocorticoid hormone, plays a crucial role in several physiological and pathological processes, influencing the immune response and stress adaptation. Its fluctuating levels in biological fluids underscore the significance of detecting this analyte for diagnosis and monitoring. Electrochemical sensors show promise for quick, cost-effective detection in unconventional biological samples. Their high sensitivity, specificity, and potential for miniaturization make them suitable for wearables and on-site analyses. The objective of this study was to develop an aptasensor for COR detection in human serum and saliva. First, the electrochemical cells were printed in-lab, followed by the functionalization of the working electrodes with a nanocomposite based on Au and Pt to increase the sensitivity. To enhance specificity, an aptamer was immobilized on the surface through thiol-Au chemistry by applying multipulse amperometry. Confirmation of the functionalization was achieved through cyclic voltammetry (CV) and electrochemical impedance spectroscopy. The detection protocol involved incubating the aptasensor with COR, and CV was employed for COR detection and was applied in the analysis of real samples. In conclusion, an aptasensor was designed for the specific electrochemical detection of COR. This work was supported by a grant of the Romanian Ministry of Education and Research, CNCS-UEFISCDI, PN–III–P1-1.1-TE-2021-1543, within PNCDI III and the Iuliu Hațieganu UMF internal grant no. 648/3.11.01.2024.


Approaches to the enzymatic synthesis of hypermodified DNA polymers and their application in development of modified aptamers

Marek Ondruš, Michal Hocek

Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nam. 542/2, 160 00 Prague 6, Czech Republic

Enzymatic synthesis of DNA is well-established method but it is highly desired to develop versatile enzymatic approaches for hypermodified DNA composed exclusively only from base-modified
2´-deoxyribonucleoside triphosphates. Base-modified dNTPs open new possibilities to explore novel bio-physical and theranostic properties of modified DNA. Therefore, we designed and synthesized two series of all four hydrophobically-modified dNTPs and used them for enzymatic synthesis of hypermodified DNA as an example of sequence-specific functionalized polymer. Due to modifications, hypermodified DNA cannot be sequenced directly by common sequencing platforms. Therefore, we developed method for replication of hypermodified DNA into natural DNA which was then easily sequenced and provided information about fidelity of DNA polymerase. Moreover, we developed new beneficial alternative for enzymatic synthesis of modified single-stranded DNA from double-stranded hybrid duplex where template and non-modified primer were efficiently removed for their application on the characterization and development of modified nucleic acids aptamers. Nucleic acid aptamers are short sequence-specific ssDNA/RNA polymers able to bind a wide variety of targets via protein-nucleic acid interactions with affinity rivalling antibodies. Despite this, there is still a major challenge for binding to “undruggable” targets such as hydrophobic proteins. To address this problem, we are developing aptamers bearing hydrophobic moieties incorporating the best attributes of two types of biopolymers: huge conformational flexibility of ssDNA combined with diversity-enhancing protein-like moieties. We have successfully selected modified aptamer bearing hydrophobic modifications, such as the 7-phenylbutyl-7-deazaadenine-modified DNA aptamer resulting in high binding affinity for the Heat Shock Protein 70 (HSP70). This work was supported by Czech Science Foundation (EXPRO), 20-00885X.


Screening and Evaluation of Aflatoxin B1-Specific Aptamers Using Gold Nanoparticle-Based HT-SELEX Technology

Shazia Shareef, Hariprasad P

Indian Institute of Technology Delhi, New Delhi, India

Aflatoxins, potent carcinogenic secondary metabolites, are produced by Aspergillus flavus and A. parasiticus. The ingestion of Aflatoxin-contaminated food/feed is associated with severe health risks, notably Hepatocellular carcinoma. Therefore, ensuring the safety of food and feed necessitates the precise detection and quantification of aflatoxins. This study, focused on selecting Aflatoxin B1 (AFB1) specific aptamers using a novel SELEX approach was employed, utilizing gold nanoparticles (AuNPs) as the separation probe without the immobilization step, facilitated by the binding interaction between single-stranded DNA (ssDNA) aptamers and AuNPs. The enrichment progress during 15 SELEX rounds was monitored through an AuNPs-based colorimetric assay for AFB1 in each cycle. Following confirmation of enrichment, the pooled aptamers from the 4th, 8th, 12th, and 15th cycles underwent Next Generation Sequencing. Analysis of the sequencing data, performed using Aptasuite and MEME suite for clustering and motif identification, respectively, resulted in the selection of 17 aptamers for further investigation. The selected aptamers underwent sensitivity and dissociation constant (kD) analysis using various methods, including AuNPs-based colorimetric assay, circular dichroism spectrometry, and SyBr Green I-based fluorescence assay. The kD of the top aptamers ranged from 1 to 2 nM, highlighting their strong binding affinity for AFB1. Fluorescence-based methods enhance sensitivity and enable real-time monitoring, facilitating dynamic tracking of binding interactions. Circular dichroism spectroscopy contributes insights into the conformational changes of aptamers induced by aflatoxin binding, thereby elucidating structural alterations crucial to the recognition process. Cross-reactivity towards other mycotoxins was also determined. To gain insights into the molecular interactions, molecular docking and simulation analyses were conducted for the top aptamer with AFB1.


UTexas Aptamer Database: the collection and long-term preservation of aptamer sequence information for research advancement (V)

Shriya Swamy, Ali Askari, Gwendolyn M Stovall

The growing interest in aptamer research, exemplified by the increasing volume of aptamer publications in recent years has underscored the necessity for a centralized resource dedicated to aptamer information. To meet this demand the UTexas Aptamer Database, a comprehensive publicly available aptamer database, serves as a repository for aptamer data designed to fulfill pivotal roles in the field. As a unifying platform for aptamer data, the UTexas Aptamer Database standardizes aptamer reporting, fosters opportunities to advance current research, and focuses on the long-term preservation of aptamer information. While several aptamer databases have emerged in previous years, many have been abandoned or removed from public access due to inherent limitations. Inspired by earlier database initiatives, the UTexas Aptamer Database aims to construct the largest comprehensive database to preserve aptamer research and knowledge while prioritizing user friendliness, interactivity, searchability, and public availability. The UTexas Aptamer Database was designed and developed through the systematic collection and peer review of aptamer information from 1990 to present day, and encompasses critical information, including but not limited to, aptamer sequences, binding characteristics, and selection methodology. All data collection is followed by an internal review process conducted by trained researchers to ensure accuracy and consistency. To maintain continual collection and review of aptamer data, sustaining mechanisms were implemented such as training protocols, an aptamer submission interface, independent data storage from the database platform, and an expanding team of researchers committed to updating and enhancing the database. At present, the UTexas aptamer database stands as the largest aptamer database in terms of the sequence entries with 1,475 internally reviewed aptamer records while holding a commitment to the preservation and advancement of aptamer research. Acknowledgement: This work was funded by The University of Texas Freshman Research Initiative, which was supported by the Howard Hughes Medical Institute (#52008124, concluded in 2021), and the College of Natural Sciences.


Aptamer-mediated targeting of MMP14 as a potential therapeutic strategy for low bone mass

Yinuo Xie, Xiaodan Yu, Jingyu Cui, Simon CC Shiu, Kathryn SE Cheah & Julian A Tanner

School of Biomedical Sciences, The University of Hong Kong

Osteopenia, a concern in aging and congenital disorders, involves Mmp14, a matrix metalloproteinase crucial for the transition from chondrocytes to osteoblasts. Ablating Mmp14 in mice increased trabecular bone, enhancing PTH impact on osteoblastogenesis. Inhibiting MMP14 may be a potential therapeutic strategy for osteopenia. Antisense oligonucleotides (ASO), a common gene knockdown therapy, modify gene expression and mRNA splicing in genetic disorders. Stabilization strategies, like self-assembled DNA nanostructures, aid intracellular delivery. Combining aptamers with DNA nanostructures addresses several limitations, allowing specific targeting of molecules, surfaces, and cells. Herein, this study is aiming to develop aptamer-mediated gene silencing therapeutics targeting osteoblasts for bone and cartilage. We have identified a single-stranded DNA (ssDNA) aptamer targeting osteoblasts through cell-SELEX and high-throughput sequencing, utilizing the MC3T3-E1 cell line as the target and the ATDC-5 chondrocyte cell line as the control. Three aptamers were chosen based on next-generation sequencing (NGS) and phylogenetic relationships, and their binding affinity and selectivity were assessed using flow cytometry. The selected aptamers demonstrated nanomolar-range dissociation constants (Kd values), displaying robust binding affinity and selectivity under physiological conditions. Truncated versions of the aptamer lost their binding capacity, highlighting the importance of the full length for optimal binding ability. Confocal laser scanning microscope studies confirmed the aptamer’s targeting of MC3T3-E1 cell surfaces. With high affinity, specificity, stability, and specific surface recognition of osteoblasts, these aptamers exhibit potential for targeting osteoblasts in various applications.


Split-aptamer binding assay towards in vivo continuous vancomycin monitoring in the brain (V)

Cátia Santa1, Heather A Clark2, Bastian Hengerer3, Khulan Sergelen1

1BioMed X Institute, Im Neuenheimer Feld 515, 69120 Heidelberg, Germany

2School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona85281, United States

3Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88397 Biberach an der Riss, Germany

The continuous monitoring of drugs in the brain is essential for the understanding of their mechanism of action. Although various strategies have been developed to tackle this necessity there are still requirements that need to be addressed and improved.The ideal drug monitoring sensor in the brain should be able to detect the molecule of interest selectively, quantitatively, reversibly, robustly, and continuously at the appropriate concentration range, with the relevant spatial and temporal resolution. To enable time-course pharmacokinetic (PK) studies, we are developing a fiber optics-based in vivo biocompatible biosensor. We will employ aptamers as our selective sensing element and characterize the affinity and specificity suitable for continuous (reversible) sensing in a physiologically relevant temporal scale for a self-contained sensor. To develop the reversible, model drug detection assay, we apply a sandwich-assay by splitting Vancomycin binding structure changing DNA aptamer into two segments that interact to form a complex only in the presence of analyte. The assay is evaluated for affinity, limit of detection, stability and reversibility in standard buffer and complex matrix in physiological conditions, with the perspective of deploying it in the brain of living animals.


Probing the recognition site of hydrophobic 7-phenylbutyl-7-deazaadenine-modified HSP70 DNA aptamer and its dependence of modified nucleobases

Pablo Alberto Franco Urquijo, Marek Ondruš, Michal Hocek

Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nam. 542/2, 160 00 Prague 6, Czech Republic

Aptamers, short sequence-specific RNA or single stranded DNA (ssDNA) that binds to their cognate target are selected by in vitro systematic evolution of ligands by exponential enrichment (SELEX) from randomized oligonucleotide pools. Typically, natural nucleotide libraries constrain the available chemical diversity resulting in a lower structural repertoire for target interactions. To overcome this, libraries with enhancing protein-like moieties have been produced that include a range of chemical modifications conferring advantages such as increased affinity, specificity and aptamer expanded epitopes. Between this modifications, hydrophobic modifed libraries have been promisingly used for “undruggable “proteins resulting in an improved success rate and novel functionalities. Within the hydrophobic modified libraries used for SELEX, the 7-phenylbutyl-7-deazaadenine-modified DNA aptamer selected via PEX and magnetic bead-based SELEX resulted in high affinity and specific aptamers to the Hsp70 protein. Modified aptamers displayed low nanomolar range KD compared with their natural counterpart (>5 µM) demonstrating the importance of its hydrophobic modification for their binding affinity. Due to this, the impact of the chemical modification with its target and the minimal binding sequence is being tested. Modified truncations were produced by an alternative enzymatic synthesis of modified ssDNA obtained from double-stranded (RNA-DNA) hybrid duplex. By this approach, the minimal binding sequence is being determined. In addition, flexibility and length of the linker connecting the modification and their impacts on the binding properties are being tested. By using this post-SELEX modification approach, we aim to improve the performance of the previously selected aptamer and get a deeper insight about the importance of the hydrophobic moieties for their binding properties. This work was supported by Czech Science Foundation (EXPRO), 20-00885X.

CAPTCHA
Please wait...