Novel biotechnical vector integrates viral and synthetic features for targeted cancer therapy

Gene therapy offers the possibility of addressing cancer at its molecular roots by targeting disease-causing genes rather than relying solely on surgery, chemotherapy, or radiotherapy. Among RNA-based strategies, microRNA (miRNA) sponges and short-hairpin RNAs (shRNAs) have emerged as promising tools to silence oncogenes and restore tumor-suppressor pathways. However, clinical application remains constrained by delivery inefficiency, instability, and off-target toxicity. Viral and non-viral vectors each present strengths and limitations: while viral vectors provide high transfection efficiency, they often cause immune responses and mutagenesis risks; non-viral carriers are safer but lack sufficient delivery efficiency. This context has driven the development of hybrid systems, culminating in the Vir-inspired Biotechnical Vector (VIBV), a novel platform integrating viral features, nanotechnology, and synthetic design for precise tumor targeting.

shRNA and miRNA Sponges

shRNAs mimic endogenous pre-miRNAs and, through cellular RNA interference machinery, degrade oncogenic mRNAs such as MYC or VEGF, making them valuable for silencing tumor-promoting pathways. miRNA sponges, by contrast, are artificial sequences that sequester oncogenic miRNAs (e.g., miR-21, miR-155), thereby releasing tumor suppressor genes from repression. Both strategies have shown strong potential but demand efficient and tumor-specific delivery systems to achieve therapeutic success.

Challenges of current delivery systems

Existing vectors face multiple barriers: low transfection rates, instability in circulation, limited tumor specificity, immune activation, and manufacturing constraints. Viral vectors (adenoviruses, retroviruses, AAVs, bacteriophages, oncolytic viruses) have demonstrated efficacy in gene transfer and tumor killing but suffer from immunogenicity, insertional mutagenesis, and limited repeat administration. Non-viral vectors (liposomes, nanoparticles, exosomes, hydrogels, dendrimers) offer safety, affordability, and large cargo capacity but are hampered by poor intracellular delivery and endosomal escape. These shortcomings limit the translation of RNA therapeutics to the clinic.

Advances in hybrid and nanotechnology-based systems

Hybrid vectors that combine viral and non-viral properties-such as virus-like particles (VLPs) and lipid-polymer hybrids-improve RNA stability and tumor targeting with reduced toxicity. Parallel advances in nanorobots and nanomotors have shown promise for pH-responsive and magnetically controlled drug delivery, enhancing specificity within the tumor microenvironment (TME). These innovations informed the design of VIBV.

Vir-inspired biotechnical vector (VIBV)

The VIBV is a next-generation hybrid delivery platform designed for personalized, tumor-specific RNA therapy. Key features include:

• Spindle-shaped nanostructure for deep tumor penetration.

• Polyethylene glycolylated liposomal coat to evade immunity and extend circulation.

• Stimuli responsiveness to tumor acidity, hypoxia, and high glutathione levels, ensuring selective activation.

• Motile sperm-like nanomotor tail for enhanced navigation in biological fluids.

The VIBV sequentially delivers four types of genetic cargo:

1. miRNA sponges to neutralize oncogenic miRNAs.

2. shRNAs to silence tumor-promoting genes.

3. Tumor-specific antigen mRNAs to stimulate anti-cancer immunity.

4. Cyclin-targeting RNAs to arrest cancer cell proliferation.

This multi-layered design allows simultaneous genetic reprogramming and immune activation while sparing healthy tissues.

Mechanism of action

Once injected, VIBV vectors circulate stealthily until guided into the tumor by pH and hypoxia cues. After membrane fusion, their cargo is released into the cytoplasm in a controlled sequence. Nanomotors direct miRNA sponges and shRNAs to their targets, tumor antigens are expressed to trigger immune responses, and cyclin-inhibitory RNAs block tumor cell division. Together, these processes produce tumor regression through genetic silencing and immune engagement.

Preclinical evidence

Preclinical models have demonstrated the potential of RNA therapeutics, including shRNAs targeting KIF23 in hepatocellular carcinoma, miRNA replacement in pancreatic ductal adenocarcinoma, and circRNA inhibition in colorectal and lung cancers. Similarly, VLP-based and nanomotor-enabled delivery systems have improved tumor suppression, validating the concept of hybrid designs. Although still theoretical, the VIBV integrates these advances into a unified delivery system with improved precision and biocompatibility.

Limitations and future directions

The VIBV concept remains largely preclinical, with its complexity, scalability, and regulatory challenges requiring further validation. Concerns regarding manufacturing reproducibility, long-term safety, and translation from animal models to humans must be addressed. Nevertheless, by uniting viral mimicry with synthetic nanotechnology, VIBV represents a pioneering step toward personalized and cost-effective RNA-based cancer therapy.

Conclusion

Targeted RNA therapies hold transformative potential in oncology, but delivery inefficiency has been their critical barrier. The Vir-inspired Biotechnical Vector offers an innovative approach, combining the efficiency of viral mechanisms with the safety and flexibility of synthetic nanocarriers. By enabling tumor-responsive, multi-cargo RNA delivery, VIBV could redefine the future of cancer therapy-pending further experimental validation and clinical translation.