PEI-assisted boronate affinity magnetic nanoparticle-based SELEX for efficient in vitro evolution of saponin-binding aptamers

The application of aptamers in the repair of bone, nerve, and vascular tissues

Aptamers represent a distinct category of short nucleotide sequences or peptide molecules characterized by their ability to bind to specific targets with high precision. These molecules are predominantly synthesized through SELEX (Systematic Evolution of Ligands by Exponential Enrichment) technology. Recent findings indicate that aptamers may have significant applications in regenerative medicine, particularly in the domain of tissue repair. In comparison to other bioactive agents, aptamers exhibit superior specificity and affinity, are more readily accessible, and can be chemically modified, thereby presenting a promising avenue for the functionalization of tissue engineering materials in tissue repair applications. This review delineates the properties of aptamers and examines the methodologies and advancements related to aptamer-functionalized hydrogels, nanoparticles, and electrospun materials. It categorizes the four primary functions of aptamers in tissue repair, namely regeneration, delivery systems, anti-inflammatory actions, and pro-coagulation effects. Furthermore, the review explores the utilization of aptamer-functionalized tissue engineering materials in the repair of bone, nerve, and vascular tissues, highlighting the mechanisms by which aptamers facilitate tissue growth and repair through regenerative properties and their role in transporting substances that promote repair. Lastly, the review addresses the future prospects and challenges associated with the application of aptamers in tissue repair, offering novel insights and directions for further research and application in this domain.

Recent progress of SELEX methods for screening nucleic acid aptamers

Nucleic acid aptamers are oligonucleotide sequences screened by an in vitro methodology called Systematic Evolution of Ligands by Exponential Enrichment (SELEX). Known as "chemical antibodies", aptamers can achieve specific recognition towards the targets through conformational changes with high affinity, and possess multiple attractive features including, but not limited to, easy and inexpensive to prepare by chemical synthesis, relatively stable and low batch-to-batch variability, easy modification and signal amplification, and low immunogenicity. Now, aptamers are attracting researchers' attentions from more than 25 disciplines, and have showed great potential for application and economic benefits in disease diagnosis, environmental detection, food security, drug delivery and discovery. Although some aptamers exist naturally as the ligand-binding elements of riboswitches, SELEX is a recognized method for aptamers screening. After thirty-two years of development, a series of SELEX methods have been investigated and developed, as well as have shown unique advantages to improve sequence performances or to explore screening mechanisms. This review would mainly focus on the novel or improved SELEX methods that are available in the past five years. Firstly, we present a clear overview of the aptamer's history, features, and SELEX development. Then, we highlight the specific examples to emphasize the recent progress of SELEX methods in terms of carrier materials, technical improvements, real sample-improved screening, post-SELEX and other methods, as well as their respects of screening strategies, implementation features, screening parameters. Finally, we discuss the remaining challenges that have the potential to hinder the success of SELEX and aptamers in practical applications, and provide the suggestions and future directions for developing more convenient, efficient, and stable SELEX methods in the future.

Recent Advances in Micro/Nanomaterial-Based Aptamer Selection Strategies

Aptamers are artificial nucleic acid ligands that have been employed in various fundamental studies and applications, such as biological analyses, disease diagnostics, targeted therapeutics, and environmental pollutant detection. This review focuses on the recent advances in aptamer discovery strategies that have been used to detect various chemicals and biomolecules. Recent examples of the strategies discussed here are based on the classification of these micro/nanomaterial-mediated systematic evolution of ligands by exponential enrichment (SELEX) platforms into three categories: bead-mediated, carbon-based nanomaterial-mediated, and other nanoparticle-mediated strategies. In addition to describing the advantages and limitations of the aforementioned strategies, this review discusses potential strategies to develop high-performance aptamers.