Abstract
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 (NH2-MSNs) were synthesized using a modified sol–gel method and characterized by FTIR, BET, TEM, SEM, X-ray diffraction, DLS, and 1H-NMR. MDR1-siRNA was loaded within NH2-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 NH2-MSNs had a particle size of ≈ 100 nm and pore size of ≈ 5 nm. siRNA was loaded into NH2-MSNs with a high loading capacity of 20% w/w. Chitosan coating on the surface of siRNA-NH2-MSNs significantly improved the siRNA protection against enzyme activity compared to naked siRNA-NH2-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.
Highlights
SiRNA is a promising technology for cancer gene therapy, effective cytoplasmic delivery has remained a significant challenge
mesoporous silica nanoparticles (MSNs)’s pore capping with gatekeeper molecules prevents the cargo from leaking before delivery to the target site, and drug release can occur only in response to a specific s timulus[7,8,9,10]. Passive targeting is another advantage of using MSN for cancer gene therapy, as 20–200 nm nanoparticles can passively accumulate at higher concentrations in tumor sites than in normal tissues, owing to the tumor vessels’ enhanced permeability and retention (EPR) e ffect[11,12]
The results indicate that TAT-conjugated nanoparticles significantly increase cellular uptake of nanoparticles in both cell lines when the control sample is considered to be polyethylene glycol (PEG)-chitosan-NH2-MSN treated cells
Summary
SiRNA is a promising technology for cancer gene therapy, effective cytoplasmic delivery has remained a significant challenge. Folate-targeted nanoparticles were harvested by folate receptor-rich HeLa-RDB and produced a chemosensitized phenotype of the multidrug-resistant cancer cells Since their discovery in 1998, RNA interferences (RNAi) have attracted increasing attention in medical research due to their high suppressing potential against the expression of disease-promoting g enes[1,2]. MSN’s pore capping with gatekeeper molecules prevents the cargo from leaking before delivery to the target site, and drug release can occur only in response to a specific s timulus[7,8,9,10] Passive targeting is another advantage of using MSN for cancer gene therapy, as 20–200 nm nanoparticles can passively accumulate at higher concentrations in tumor sites than in normal tissues, owing to the tumor vessels’ enhanced permeability and retention (EPR) e ffect[11,12]. Favorable properties including safety, cost-effectiveness, non-immunogenicity, high stability, simple conjugation with various molecules, and binding affinity to the folate receptor (FR) after conjugation highlight the folate-targeting system as a considerable intelligent drug delivery system
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
