Engineered Hsp Protein Nanocages for siRNA Delivery

Abstract

The efficient delivery of small interfering RNA (siRNA) to tumor cells still remains a great challenge. Of the various nanocarriers, protein nanocages have attracted extensive interest due to their unique structure and suitable characteristics derived from their proteinaceous nature. However, most reported protein nanocages that are developed are based on virus capsid proteins, which may raise safety concerns, including those related to gene mutation and carcinogenesis. The development of nonviral protein-based systems for siRNA delivery is greatly needed. In this study, a novel siRNA delivery system based on heat shock protein (Hsp) nanocages is developed by a genetic engineering method. The delivery system could condense siRNA into stable complexes and protect the condensed siRNA from degradation. A cellular uptake analysis shows that siRNA is introduced into tumor cells mediated by Hsp-R9 nanocages. Green fluorescent protein (GFP) expression in HeLa-EGFP cells is significantly downregulated by Hsp-R9/siRNA complexes. The results indicate that Hsp nanocages may be a good platform for siRNA delivery into tumor cells.

Design and Synthesis of Piperazine-Based Compounds Conjugated to Humanized Ferritin as Delivery System of siRNA in Cancer Cells

“… 1 − 3 In the last years, many nucleic acid delivery vectors including cationic lipids and polymers have been explored to circumvent these restrictions and to reach the best compromise between transfection efficiency and cytotoxicity. 4 , 5 Nanoparticle-based delivery systems have been widely used for their ability to protect the siRNA cargo from nuclease activity, for tissue targeting and cell specificity, and for efficient cell membrane crossing properties. 6 However, there are significant concerns regarding their safety and biocompatibility when used for human therapy.…”

Overcoming Hurdles in Nanoparticle Clinical Translation: The Influence of Experimental Design and Surface Modification

“…In general, protein-based nanoparticles have several desirable characteristics, including but not limited to biodegradability, lack of immunogenicity, lack of toxicity, improved drug solubility, enhanced circulation time, preferential uptake in tumor and inflammatory tissues, and a stable structure across a range of pH and/or temperatures [54]. Other proteins that are being explored for nanoparticle drug delivery include heat-shock proteins [55], silk proteins [56], soy proteins [57], collagen [58], elastin [59], gelatin [60], and VEGF [61].…”

Developing Protein-Based Nanoparticles as Versatile Delivery Systems for Cancer Therapy and Imaging

“…However, other non-viral PNPs have been recently repurposed into vehicles for gene delivery. For example, Guan et al utilized Hsp for siRNA delivery [37]. Hsp was genetically fused with an arginine-rich peptide (R9) at its C-terminus, resulting in a positively charged exterior surface that facilitated the electrostatic binding of negatively charged siRNA.…”