High accuracy of single-molecule real-time sequencing in detecting a rare α-globin fusion gene in carrier screening population.

INTRODUCTION: The α-globin fusion gene between the HBA2 and HBAP1 genes becomes clinically important in thalassemia screening because this fusion gene can cause severe hemoglobin (Hb) H disease when combining with α0 -thalassemia (α0 -thal). Due to its uncommon rearrangement in the α gene cluster without dosage changes, this fusion gene is undetectable by common molecular testing approaches used for α-thal diagnosis. METHODS: In this study, we used the single-molecule real-time (SMRT) sequencing technique to detect this fusion gene in 23 carriers identified by next-generation sequencing (NGS) among 16,504 screened individuals. Five primers for α and ß thalassemia were utilized. RESULTS: According to the NGS results, the 23 carriers include 14 pure heterozygotes, eight compound heterozygotes with common α-thal alleles, and one homozygote. By using SMRT, the fusion mutant was successfully detected in all 23 carriers. Furthermore, SMRT corrected the diagnosis in two "pure" heterozygotes: one was compound heterozygote with anti-3.7 triplication, and the other was homozygote. CONCLUSION: Our results indicate that SMRT is a superior method compared to NGS in detecting the α fusion gene, attributing to its efficient, accurate, and one-step properties.

Self-assembled oligomeric procyanidin-insulin hybrid nanoparticles: a novel strategy for controllable insulin delivery.

Natural oligomeric procyanidin (OPC) with high biological and pharmacological activities was successfully used to synthesize OPC-insulin (OPC-INS) nanoparticles with different aggregation sizes for sustained and controlled delivery of hydrophilic insulin. The aggregation size of OPC-INS nanoparticles was regulated by OPC concentration, pH value, and incubation time. The fabrication mechanism would be that OPC and insulin self-assembled into a mixture of insulin aggregates via intermolecular interactions. In the self-assembly of insulin, OPC could serve both in the encompassing of insulin aggregates as a stabilizer and cross-linking different amounts of insulin aggregates into OPC-INS nanoparticles as interphase. OPC-INS nanoparticles not only demonstrated effective insulin drug loading but also exhibited aggregation-size-dependent and controlled insulin release performance in vitro. In the best case for OPC-INS nanoparticles, only ∼21% of insulin was released in 37 days. This study showed that the OPC-INS nanosystem is promising to serve as a long-acting insulin release formulation, and OPC has great potential as a drug carrier for nanomedicine.