Electrosprayable Levan-Coated Nanoclusters and Ultrasound-Responsive Drug Delivery for Cancer Therapy.

In this study, we synthesized levan shell hydrophobic silica nanoclusters encapsulating doxorubicin (L-HSi-Dox) and evaluated their potential as ultrasound-responsive drug delivery systems for cancer treatment. L-HSi-Dox nanoclusters were successfully fabricated by integrating a hydrophobic silica nanoparticle-doxorubicin complex as the core and an amphiphilic levan carbohydrate polymer as the shell by using an electrospray technique. Characterization analyses confirmed the stability, size, and composition of the nanoclusters. In particular, the nanoclusters exhibited a controlled release of Dox under aqueous conditions, demonstrating their potential as efficient drug carriers. The levanic groups of the nanoclusters enhanced the targeted delivery of Dox to specific cancer cells. Furthermore, the synergism between the nanoclusters and ultrasound effectively reduced cell viability and induced cell death, particularly in the GLUT5-overexpressing MDA-MB-231 cells. In a tumor xenograft mouse model, treatment with the nanoclusters and ultrasound significantly reduced the tumor volume and weight without affecting the body weight. Collectively, these results highlight the potential of the L-HSi-Dox nanoclusters and ultrasound as promising drug delivery systems with an enhanced therapeutic efficacy for biomedical applications.

Multiple suppressing small interfering RNA for cancer treatment-Application to triple-negative breast cancer.

Certain cancers, such as triple-negative breast cancer (TNBC), pose a challenging prognosis due to the absence of identifiable hormone-related receptors and effective targeted therapies. Consequently, novel therapeutics are required for these cancers, offering minimal side effects and reduced drug resistance. Unexpectedly, siRNA-7, initially employed as a control, exhibited significant efficacy in inhibiting cell viability in MDA-MB-231 cells. Through a genome-wide search of seed sequences, the targets of siRNA-7 were identified as cancer-related genes, namely PRKCE, RBPJ, ZNF737, and CDC7 in MDA-MB-231 cells. The mRNA repression analysis confirmed the simultaneous suppression by siRNA-7. Combinatorial administration of single-targeting siRNAs demonstrated a comparable reduction in viability to that achieved by siRNA-7. Importantly, siRNA-7 selectively inhibited cell viability in MDA-MB-231 cells, while normal HDF-n cells remained unaffected. Furthermore, in a xenograft mouse model, siRNA-7 exhibited a remarkable 76% reduction in tumor volume without any loss in body weight. These findings position siRNA-7 as a promising candidate for a novel, safe, specific, and potent TNBC cancer therapeutic. Moreover, the strategy of multiple suppressing small interfering RNA holds potential for the treatment of various diseases associated with gene overexpression.

Efficient and safe small RNA delivery to macrophage using peptide-based nanocomplex.

As one of the gene therapies, RNA interference (RNAi) effectively suppresses only specific genes, targeting various diseases in which they are involved. For the successful process of RNAi, efficient and safe delivery of small RNAs, including small interfering RNA and short hairpin RNA, is essential. Herein, an S-R11 fusion peptide, SPACE peptide conjugated with poly-arginine, was introduced to deliver small RNAs into immune cells that are difficult to transfect. This S-R11 peptide stably formed a spontaneous self-assembling nanocomplex through electrostatic attraction and hydrogen bonding with small RNAs. The nanocomplex showed about 5.3-fold better permeation efficiency than the conventional Lipofectamine™ 2000 for RAW 264.7 macrophage cells. Moreover, it induced about 66.2% silencing effect of the target gene in the cells activated with polyinosinic:polycytidylic acid (poly (I:C)). In addition, the cell viability of fusion peptide was ensured even in a concentration range exceeding the concentration used in the nanocomplex. Based on these results, it is expected that the nanocomplex in this study can be used as a new gene delivery system that can overcome the challenge of gene therapies to immune cells.

Synergistic gene delivery by self-assembled nanocomplexes using fusion peptide and calcium phosphate.

Gene therapy can be a promising therapeutic approach to cure the fundamental causes of incurable genetic diseases. Because virus carriers are costly and can cause inflammation and immunogenicity, efficient non-viral carriers need to be developed for broader gene therapy applications. Therefore, we designed novel synergistic nanocomplexes for efficient transfection incorporated by the fusion of nuclear localization signal and cell-penetrating peptides with calcium phosphate. Fusion peptides were able to package large plasmid DNAs into nanocomplexes spontaneously and efficiently. After optimization, S-R/CaP or S-S/CaP nanocomplexes significantly improved specific luciferase expression up to 2-fold compared to Lipofectamine® 2000. In addition, the large Cas9-encoding plasmids were transfected into HEK293T cells more efficiently than Lipofectamine® 2000. Furthermore, subcutaneously injected cells to mice maintained more stable protein expression until 10 days than Lipofectamine® 2000. Moreover, the biocompatibility was revealed by observing negligible cytotoxicity, histological difference, and inflammatory cytokine release. Consequently, the new chimeric strategy will be an efficient and safe gene carrier into cells and tissues to treat various genetic diseases through gene therapy.

Novel fusion peptide-mediated siRNA delivery using self-assembled nanocomplex.

BACKGROUND: Gene silencing using siRNA can be a new potent strategy to treat many incurable diseases at the genetic level, including cancer and viral infections. Treatments using siRNA essentially requires an efficient and safe method of delivering siRNA into cells while maintaining its stability. Thus, we designed novel synergistic fusion peptides, i.e., SPACE and oligoarginine. RESULTS: Among the novel fusion peptides and siRNAs, nanocomplexes have enhanced cellular uptake and gene silencing effect in vitro and improved retention and gene silencing effects of siRNAs in vivo. Oligoarginine could attract siRNAs electrostatically to form stable and self-assembled nanocomplexes, and the SPACE peptide could interact with the cellular membrane via hydrogen bonding. Therefore, nanocomplexes using fusion peptides showed improved and evident cellular uptake and gene silencing of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) via the lipid raft-mediated endocytosis pathway, especially to the HDFn cells of the skin, and all of the fusion peptides were biocompatible. Also, intratumorally injected nanocomplexes had increased retention time of siRNAs at the site of the tumor. Finally, nanocomplexes demonstrated significant in vivo gene silencing effect without overt tissue damage and immune cell infiltration. CONCLUSIONS: The new nanocomplex strategy could become a safe and efficient platform for the delivery of siRNAs into cells and tissues to treat various target diseases through gene silencing.