siRNA delivery using intelligent chitosan-capped mesoporous silica nanoparticles for overcoming multidrug resistance in malignant carcinoma cells

• Published in: Scientific reports 2021-10, Vol.11 (1), p.20531-20531, Article 20531
• Main Authors: Heidari, Razieh, Khosravian, Pegah, Mirzaei, Seyed Abbas, Elahian, Fatemeh
• Format: Article
• Language: English
• Subjects: 631/337; 631/61; 631/67; 631/80; ATP Binding Cassette Transporter, Subfamily B - genetics; Cancer; Carcinoma - therapy; Chitosan; Chitosan - chemistry; Coatings; Cytotoxicity; Drug resistance; Drug Resistance, Neoplasm; Enzymatic activity; Flow cytometry; Folic acid; Folic Acid - chemistry; Gene therapy; Gene transfer; Genetic Therapy - methods; HeLa Cells; Humanities and Social Sciences; Humans; MDR1 protein; multidisciplinary; Multidrug resistance; Multidrug resistant organisms; Nanoparticles; Nanoparticles - chemistry; P-Glycoprotein; Phenotypes; Pore size; Protein folding; RNA, Small Interfering - administration & dosage; Science; Science (multidisciplinary); Silica; Silicon Dioxide; siRNA; Transcription; Vitamin B; X-ray diffraction
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-00085-0

Although siRNA is a promising technology for cancer gene therapy, effective cytoplasmic delivery has remained a significant challenge. In this paper, a potent siRNA transfer system with active targeting moieties toward cancer cells and a high loading capacity is introduced to inhibit drug resistance. Mesoporous silica nanoparticles are of great potential for developing targeted gene delivery. Amino-modified MSNs (NH 2 -MSNs) were synthesized using a modified sol–gel method and characterized by FTIR, BET, TEM, SEM, X-ray diffraction, DLS, and 1 H-NMR. MDR1-siRNA was loaded within NH 2 -MSNs, and the resulting negative surface was capped by functionalized chitosan as a protective layer. Targeting moieties such as TAT and folate were anchored to chitosan via PEG-spacers. The loading capacity of siRNA and the protective effect of chitosan for siRNA were determined by gel retardation assay. MTT assay, flow cytometry, real-time PCR, and western blot were performed to study the cytotoxicity, cellular uptake assay, targeting evaluation, and MDR1 knockdown efficiency. The synthesized NH 2 -MSNs had a particle size of ≈ 100 nm and pore size of ≈ 5 nm. siRNA was loaded into NH 2 -MSNs with a high loading capacity of 20% w/w. Chitosan coating on the surface of siRNA-NH 2 -MSNs significantly improved the siRNA protection against enzyme activity compared to naked siRNA-NH 2 -MSNs. MSNs and modified MSNs did not exhibit significant cytotoxicity at therapeutic concentrations in the EPG85.257-RDB and HeLa-RDB lines. The folate-conjugated nanoparticles showed a cellular uptake of around two times higher in folate receptor-rich HeLa-RDB than EPG85.257-RDB cells. The chitosan-coated siRNA-NH2-MSNs produced decreased MDR1 transcript and protein levels in HeLa-RDB by 0.20 and 0.48-fold, respectively. The results demonstrated that functionalized chitosan-coated siRNA-MSNs could be a promising carrier for targeted cancer therapy. Folate-targeted nanoparticles were specifically harvested by folate receptor-rich HeLa-RDB and produced a chemosensitized phenotype of the multidrug-resistant cancer cells.