Reduction of Recombinant Adeno-Associated Virus Vector Adsorption on Solid Surfaces by Polyionic Hydrophilic Complex Coating

Salama Ramy,Yuki Ueda,Hiroyuki Nakajima,Miya Hiroi,Yoshiomi Hiroi,Tetsuo Torisu,Susumu Uchiyama

doi:10.1016/j.xphs.2021.10.022

Abstract

Recombinant adeno-associated virus (rAAV) vectors have proven efficacy as gene therapy vehicles. However, non-specific adsorption of these vectors on solid surfaces is encountered during production, storage, and administration, as well as in quantification processes. Such adsorption has been reported to result in the loss of up to 90% of vector particles and can also result in high variability in vector genome quantification. In this study, we demonstrate the effective decrease of recombinant adeno-associated virus vector adsorption by application of a polyionic hydrophilic complex polymer coating on the surfaces of the tools used in viral vector quantification analyses [i.e., pipette tips, cryotube vials, and quantitative polymerase chain reaction (qPCR) plates]. qPCR analyses showed efficient recovery of vector particles from tools with this coating, with up to 95% of vector particle loss being prevented, leading to a higher transduction efficiency in vitro. Thus, the tested coating has the potential to be widely used in material processing in the gene therapy field.

Highlights

The establishment of the fundamentals of genetics led to the concept of gene therapy, in which genetic disorders, such as conditions caused by defective or missing genes, can be treated with intact copies of genes.[1]
Comparative quantitative polymerase chain reaction (qPCR) analysis of the rAAV1 vector handled using the polyionic hydrophilic complex (PHC)-coated and non- coated tools indicated that the coating decreased the vector adsorption onto the surfaces of the tested tools; a significant difference (p < 0.01) was observed in the recovered vector genome (VG) concentrations between the test and control groups
The PHC coating led to a significant decrease in the Recombinant adeno-associated virus (rAAV) vector adsorption onto each of the tested tools

Summary

Introduction

The establishment of the fundamentals of genetics led to the concept of gene therapy, in which genetic disorders, such as conditions caused by defective or missing genes, can be treated with intact copies of genes.[1]. Vectors have been used in the gene therapy field, each of which has its own characteristics.[2]. S. Ramy et al / Journal of Pharmaceutical Sciences 00 (2021) 1−9 expensive drug in the world, costing $2.125 million;[9] and voretigene neparvovec-rzyl (Luxturna), which has been commercially available since 2017, costs $425,000 per eye treatment.[7] The high prices can be explained by the risky and highly expensive product development steps for rAAV therapies, including production, quality control, and assay standardization,[7] as well as the cost of the preclinical studies regarding toxicity, safety, dosing, and biodistribution that are typically required for US Food and Drug Administration (FDA) approval.[10] In addition, the analytical and scientific research methods for studying rAAVs require specialized instruments and expensive tools and reagents, which prevents some laboratories from producing rAAVs or even purchasing the purified vectors as small-scale preparations.[11] more economical methods for the production of rAAV vectors, which maintain a high yield and high quality, are highly desirable.[12]

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Results

Discussion

Conclusion