Delivery of siRNA to Ewing Sarcoma Tumor Xenografted on Mice, Using Hydrogenated Detonation Nanodiamonds: Treatment Efficacy and Tissue Distribution

Abstract

Nanodiamonds of detonation origin are promising delivery agents of anti-cancer therapeutic compounds in a whole organism like mouse, owing to their versatile surface chemistry and ultra-small 5 nm average primary size compatible with natural elimination routes. However, to date, little is known about tissue distribution, elimination pathways and efficacy of nanodiamonds-based therapy in mice. In this report, we studied the capacity of cationic hydrogenated detonation nanodiamonds to carry active small interfering RNA (siRNA) in a mice model of Ewing sarcoma, a bone cancer of young adults due in the vast majority to the EWS-FLI1 junction oncogene. Replacing hydrogen gas by its radioactive analog tritium gas led to the formation of labeled nanodiamonds and allowed us to investigate their distribution throughout mouse organs and their excretion in urine and feces. We also demonstrated that siRNA directed against EWS-FLI1 inhibited this oncogene expression in tumor xenografted on mice. This work is a significant step to establish cationic hydrogenated detonation nanodiamond as an effective agent for in vivo delivery of active siRNA. polymers or dendrimers [5]), inorganic (e.g., metallic nanoparticles such as gold, iron, titanium [4]) or mineral like clay [6], silica nanoparticles [7] and nanodiamonds [8,9]. Most inorganic nanocarriers present a good-to-high chemical stability; they have a low toxicity at therapeutic dose of the drug:carrier conjugate and are able to deliver their cargo compounds into cells. Nevertheless, the high stability of inorganic nanoparticles goes with the fact that they are not biodegradable, and for pharmacological applications, this can be a limiting factor. Therefore, for the safe development of these particles, it is crucial to determine their possible elimination pathways after administration and study how they are distributed in the body.Here, we report on the use of cationic detonation nanodiamonds (DND) for the delivery of siRNA directed against Ewing sarcoma (ES) junction oncogene EWS-FLI1 to ES tumor xenografted on mice. Ewing sarcoma is a rare bone and soft tissue cancer [10] which is caused in the vast majority of cases by the formation of EWS-FLI1 oncogene. To carry siRNA, DND surface needs to be modified to be able to bind negatively charged nucleic acids by electrostatic interactions. One strategy relies on cationic polymer coating of diamond surface, which is either done by electrostatic interaction [9,11] or by covalent grafting [12,13]. However, polymer coating may lead to the formation of large aggregates by crosslinking DND to other DND via polymer chains bridging. Another strategy, the one selected for this study, is based on the direct surface modification of DND using hydrogen gas combined with microwave plasma or with annealing method. Both hydrogenation methods were recently compared [14]. It was shown that after such reductive treatment, the hydrogenated DND (H-DND) can be dispersed in water, and acquire a positive surface charge characterized by a zeta potential of ...

Harnessing subcellular-resolved organ distribution of cationic copolymer-functionalized fluorescent nanodiamonds for optimal delivery of active siRNA to a xenografted tumor in mice

“…These results support the fact that Cop + -FND:siAS is able to efficiently deliver siRNA in vivo and that intratumoral administration of this type of nanomaterials could offer therapeutic advantages over alternative delivery systems such as Lipofectamine. We recently reported that 7 nm sized detonation nanodiamonds (DNDs), rendered cationic by hydrogenation, can deliver an efficient siAS to mice bearing the same xenografted Ewing sarcoma tumor, after intravenous injection [31]. We observed a two-fold decrease (50% inhibition) of EWS-FLI1 mRNA levels in tumors of mice treated with DND:siAS compared to mice treated with DND:siCt.…”

Carbon Based Nanodots in Early Diagnosis of Cancer

“…This prevents the formation of secondary tumors (Lai et al, 2020). Nanodiamonds have been used as vector for delivery of siRNA on sarcoma cells (Claveau et al, 2020). Detonation Nanodiamonds (DNDs) have been reported to be useful in radiotherapy.…”

Enhanced penetrative siRNA delivery by a nanodiamond drug delivery platform against hepatocellular carcinoma 3D models

“…49,50 These properties have been leveraged towards the use of NDs as a platform to deliver a wide range of therapeutic and diagnostic reagents, including chemotherapy drugs, [51][52][53][54][55][56][57] peptides, [58][59][60][61] imaging agents [62][63][64] and genetic materials. [65][66][67][68][69][70][71][72] In cancer, ND-drugs have shown enhanced therapeutic efficacy in a wide range of in vitro and in vivo cancer models, including liver cancer, 53,58,73 pancreatic cancer, 55,57 breast cancer 74 and Ewing sarcoma. 75 Polyglycerolfunctionalized nanodiamonds (ND-PG) conjugated with Cy7 and showed preferential accumulation in the tumors rather than the organs when the nanoparticles were systemically administered into tumor-bearing mice.…”

“…[65][66][67][68][69][70][71][72] In cancer, ND-drugs have shown enhanced therapeutic efficacy in a wide range of in vitro and in vivo cancer models, including liver cancer, 53,58,73 pancreatic cancer, 55,57 breast cancer 74 and Ewing sarcoma. 75 Polyglycerolfunctionalized nanodiamonds (ND-PG) conjugated with Cy7 and showed preferential accumulation in the tumors rather than the organs when the nanoparticles were systemically administered into tumor-bearing mice. 76 Given the potential advantages of ND drug delivery against solid cancer, such as HCC, we evaluated NDs as an siRNA therapy delivery platform within the context of 3D cancer disease modelling.…”