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Updated: Apr 21, 2026
Porous Silicon Microparticles for Delivery of siRNA Therapeutics
Published on: January 15, 2015
Design and evaluation of endosomolytic biocompatible peptides as carriers for siRNA delivery
Wen Xu1, Ran Pan, Danyang Zhao
1Department of Chemical Engineering and Waterloo Institute for Nanotechnology, University of Waterloo , 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Abstract:
Gene therapy using RNA interference (RNAi) technology has been explored to treat cancers, by regulating the expression of oncogene. However, even though small interfering RNA (siRNA), which triggers RNAi, may have great therapeutic potential, efforts at using them in vivo have been hampered by the difficulty of effective and safe delivery into cells of interest. In this study, to develop a safe and efficient carrier for in vitro and in vivo siRNA delivery, we designed a peptide library. These peptides are improved variants of a known peptide based siRNA carrier C6. All the modifications improved the transfection efficiency of C6 to some degree. After completing prescreening for activity, several promising candidates were used for further evaluation. Selected peptides C6M3 and C6M6 could form stable complexes with siRNA. These complexes could be greatly uptaken by cells and showed a punctate perinuclear distribution. Moreover, peptide/siRNA complexes achieved high transfection efficiency in vitro without inducing substantial cytotoxicity. We have validated the therapeutic potential of this strategy for cancer treatment by targeting Bcl-2 gene in mouse tumor models, and demonstrated that tumor growth was inhibited. In order to address possible immune side effects of these peptide carriers, biocompatibility study in terms of complement activation and cytokine activation assay were carried out, whereas none of the peptides induced such effects. In conclusion, these results support the potential of these peptides as therapeutic siRNA carrier.
Insights
Researchers developed novel peptide carriers for effective small interfering RNA (siRNA) delivery in cancer gene therapy. These peptides show promise for in vivo applications, inhibiting tumor growth without significant immune response.
Area of Science:
- Biotechnology
- Molecular Biology
- Cancer Research
Background:
- RNA interference (RNAi) holds therapeutic potential for cancer by regulating oncogene expression.
- Effective in vivo delivery of small interfering RNA (siRNA) remains a significant challenge for RNAi-based cancer therapies.
Purpose of the Study:
- To design and evaluate a novel peptide library as a safe and efficient carrier for in vitro and in vivo siRNA delivery.
- To improve upon existing peptide-based siRNA carriers like C6 for enhanced transfection efficiency.
Main Methods:
- A peptide library based on the C6 carrier was designed and modified.
- Selected peptides (C6M3, C6M6) were complexed with siRNA.
- In vitro transfection efficiency, cellular uptake, intracellular distribution, and cytotoxicity were assessed.
- In vivo studies in mouse tumor models targeted the Bcl-2 gene.
- Biocompatibility was evaluated through complement and cytokine activation assays.
Main Results:
- Modified peptides C6M3 and C6M6 formed stable siRNA complexes with high cellular uptake and perinuclear distribution.
- These peptide/siRNA complexes demonstrated high in vitro transfection efficiency with minimal cytotoxicity.
- In vivo, targeting Bcl-2 gene with these complexes inhibited tumor growth in mouse models.
- No significant complement or cytokine activation was observed, indicating good biocompatibility.
Conclusions:
- The developed peptides represent promising therapeutic carriers for siRNA delivery in cancer gene therapy.
- These carriers offer a safe and effective strategy for in vivo siRNA delivery, potentially overcoming current limitations.
- Further validation supports the potential of these peptides for clinical applications in cancer treatment.
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