Aptamers are short DNA/RNA oligonucleotides capable of binding to target molecules with high affinity and specificity. The process of selecting an aptamer is called Systematic Evolution of Ligands by Exponential Enrichment (SELEX). Thanks to the inherit merits, aptamers have been used in a wide range of applications, including disease diagnosis, targeted delivery agents and therapeutic uses. To date, great achievements regarding the selection, modifications and application of aptamers have been made. However, few aptamer-based products have already successfully entered into clinical and industrial use. Besides, it is still a challenge to obtain aptamers with high affinity in a more efficient way. Thus, it is important to comprehensively review the current shortage and achievement of aptamer-related technology. In this review, we first present the limitations and notable advances of aptamer selection. Then, we compare the different methods used in the kinetic characterization of aptamers. We also discuss the impetus and developments of the clinical application of aptamers.

The CRISPR/Cas systems in prokaryotes such as bacteria and archaea are the adaptive immune system to prevent infection from viruses, phages, or other foreign substances. When viruses or phages first invade the bacteria, Cas proteins recognize and cut the DNA from viruses or phages into short fragments that will be integrated into the CRISPR array. Once bacteria are invaded again, the modified CRISPR and Cas proteins react quickly to cut DNA at the specified target location, protecting the host. Due to its high efficiency, versatility, and simplicity, the CRISPR/Cas system has become one of the most popular gene editing technologies. In this review, we briefly introduce the CRISPR/Cas systems, focus on several delivery methods including physical delivery, viral vector delivery, and non-viral vector delivery, and the applications of disease therapy. Finally, some problems in CRISPR/Cas9 technology have been proposed, such as the off-target effects, the efficiency of DNA repair mechanisms, and delivery of CRISPR/Cas system safely and efficiently to the target location.

Impaired fracture healing in aged females is still a challenge in clinics. MicroRNAs (miRNAs) play important roles in fracture healing. This study aims to identify the miRNAs that potentially contribute to the impaired fracture healing in aged females. Transverse femoral shaft fractures were created in adult and aged female mice. At post-fracture 0-, 2- and 4-week, the fracture sites were scanned by micro computed tomography to confirm that the fracture healing was impaired in aged female mice and the fracture calluses were collected for miRNA microarray analysis. A total of 53 significantly differentially expressed miRNAs and 5438 miRNA-target gene interactions involved in bone fracture healing were identified. A novel scoring system was designed to analyze the miRNA contribution to impaired fracture healing (RCIFH). Using this method, 11 novel miRNAs were identified to impair fracture healing at 2- or 4-week post-fracture. Thereafter, function analysis of target genes was performed for miRNAs with high RCIFH values. The results showed that high RCIFH miRNAs in aged female mice might impair fracture healing not only by down-regulating angiogenesis-, chondrogenesis-, and osteogenesis-related pathways, but also by up-regulating osteoclastogenesis-related pathway, which implied the essential roles of these high RCIFH miRNAs in impaired fracture healing in aged females, and might promote the discovery of novel therapeutic strategies.

Monoclonal immunoglobin (M-protein) is a serum biomarker for the diagnosis of plasma cell dyscrasias. Despite limitation of analytical sensitivity and resolution, serum protein electrophoresis and immunofixation electrophoresis are still the front-line tests for the detection of M-proteins. Herein, we developed a MALDI-TOF Mass spectrometry-based method for the screening test of M-proteins in human serum. Based on the unique mass signature of different immunoglobin isotypes, M-Proteins could be rapidly identified and typed. The method demonstrated with high analytical performance and throughput, rapid and simple, which could be a new choice for the diagnosis of plasma cell dyscrasias.

Background: Evidence-based evaluation of laboratory performances including pre-analytical, analytical and post-analytical stages of the total testing process (TTP) is crucial to ensure patients receiving safe, efficient and effective care. To conduct risk assessment, quality management tools such as Failure Mode and Effect Analysis (FMEA) and the Failure Reporting and Corrective Action System (FRACAS) were constantly used for proactive or reactive analysis, respectively. However, FMEA and FRACAS faced big challenges in determining the scoring scales and failure prioritization in the assessment of real-world cases. Here, we developed a novel strategy, by incorporating Sigma metrics into risk assessment based on quality indicators (QIs) data, to provide a more objective assessment of risks in TTP. Methods: QI data was collected for 1 year and FRACAS was applied to produce the risk rating based on three variables: (1) Sigma metrics for the frequency of defects; (2) possible consequence; (3) detection method. The risk priority number (RPN) of each QI was calculated by a 5-point scale score, where a value of RPN > 50 was rated as high-risk. Results: The RPNs of two QIs in post-analytical phase (TAT of Stat biochemistry analyte and Timely critical values notification) were above 50 which required rigorous monitoring and corrective actions to eliminate the high risks. Nine QIs (RPNs between 25 and 50) required further investigation and monitoring. After 3 months of corrective action the two identified high-risk processes were successfully reduced. Conclusions: The strategy can be implemented to reduce identified risk and assuring patient safety.

Glioblastoma (GBM) remains a significant therapeutic challenge. While GBM‐derived extracellular vesicles (EVs) are known to remodel the normal blood‐brain barrier (BBB) into a blood‐tumour barrier (BTB), the underlying mechanism is largely not understood. Here, we reveal that nucleolin (NCL) is transferred via GBM‐derived EVs to the surface of brain endothelial cells, where it promotes BTB formation. Furthermore, the NCL‐specific aptamer AS1411 exploits this pathway, crossing the BTB through receptor‐mediated transcytosis and selectively entering GBM cells in an NCL‐dependent manner. Proteolysis‐targeting chimeras (PROTACs), heterobifunctional molecules that recruit E3 ligases to degrade target proteins, show therapeutic potential but are hindered by inefficient brain penetration in GBM. Capitalizing on the BTB‐penetrating capability of AS1411 and our prior finding that AS1411 can intracellularly recruit the E3 ligase MDM2 via employing NCL as a molecular bridge, we engineered AS1411‐based PROTACs against VEGFR2 and EGFR. These PROTACs induced NCL‐ and MDM2‐dependent ubiquitination and degradation of VEGFR2 or EGFR in GBM cells, demonstrating potent anti‐tumour activity. Collectively, our findings identify EV‐transferred NCL as a key mediator of BTB formation and a functional transcytosis receptor for AS1411, providing a promising strategy for developing BTB‐permeable, targeted therapy for GBM.