Virus Development for Drug Delivery
Viral vectors are designed to be safe because they cannot replicate. The genome of a virus consists of coding and non-coding regions, with genes in the coding region producing the structural and non-structural proteins of the virus, and the non-coding region containing the cis-acting elements necessary for the virus to perform functions such as replication and packaging. Genes transferred by viral vectors dominate clinical trials for gene therapy because they are more effective and specific than physical and chemical methods.
CD Formulation offers comprehensive virus development services for the medical field, including the design and construction of appropriate viral vectors and corresponding viral biochemical assays.
Introduction of Viruses for Drug Delivery
Viral vector packaging is divided into three main categories: lentivirus (LV), adenovirus (ADV), and adeno-associated virus (AAV). Lentivirus is a viral vector modified from human immunodeficiency virus (HIV) and belongs to retrovirus; adeno-associated virus consists of icosahedral protein capsid of about 26 nm in diameter and a single-stranded DNA genome of about 4.7 kb; adenovirus is an unenveloped virus, about 90-100 nm in diameter, with a wide range of cell and tissue infectivity, and adenovirus vectors carry large gene fragments up to 7-8 kb in size. Among viral vectors, lentiviral vectors can efficiently infect almost all cells, and AAV vectors are also very efficient in delivery and are currently used in vitro gene therapy in clinical settings as a relatively mature delivery technology.
An ideal viral vector should have the following characteristics
1. The ability to encapsulate exogenous genes and form viral particles.
2. Be able to mediate the transfer and expression of exogenous genes.
3. The ability to mediate the transfer and expression of the exogenous gene; and the ability not to proliferate and spread in the environment without causing harm to the organism.
Virus Development
CD Formulation provides virus development, including virus construction, design, and virus testing. Our current virus development services include lentivirus, adenovirus, adeno-associated virus, etc.
Lentiviruses have the advantage that they are less immunogenic than adenoviruses. Low immunogenicity means that it is difficult to trigger the immune system to produce the appropriate antibodies in the body, thus affecting the effectiveness of gene transfection. Lentiviruses can carry gene-encoding sequences, interfering sequences, Cas9-gRNA, etc., and achieve gene regulation of target genes in the body through different injection methods.
The delivery mechanism of adenoviral vectors is mainly receptor-mediated. Recombinant adenovirus vectors enter the cell through receptor-mediated endocytosis, and the genome they carry enters the nucleus but does not integrate into the host cell genome, remaining outside the chromosome. The adenoviral vector is flanked by the ITR and its interior is the viral packaging signal. The vectors are chemically modified with polymers after production and purification to remove barriers to vector-host interactions.
Adeno-associated virus (AAV) vectors are non-integrating viral vectors that exist in a stand-alone form upon entry into human cells and do not integrate into the host cell genome, reducing the associated risks and providing a good safety profile.
CD Formulation offers a full range of services for viral vectors for drug delivery, based on a number of technologies and scientific talents that we possess. If you need a service that is not on the list, please contact our team as our services are not only constantly being updated, but can also be customized for your project.
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