Application Of RNA Nanohydrogels Based On DNAzyme In Cancer Co-therapy

Cancer poses a threat to human life.Now,efforts are being made to develop various biomaterials for personalized treatment.Nanoflowers have higher surface area ratio,stronger adsorption capacity and efficient loading capacity.In addition,functional nucleic acids are nucleic acid molecules with specific functions,but these functional naked DNA or RNA sequences are difficult to be internalized by target cells,and their activities are easily interfered with and easily degraded.Therefore,it is necessary to develop carriers as functional nucleic acids.In this paper,combining of RNA nanoflower,functional nucleic acid and various cancer treatment methods to achieve collaborative treatment of cancer.First of all,DNAzyme's cutting activity was utilized to design the substrates into the template chain to achieve non-violent degradation of the carrier and release drugs on demand.Manganese ions(Mn²⁺)produced by loaded manganese dioxide(Mn O₂)can solve the deficiency of endogenous ions in cells.mi R-21 antisense sequence clears mi R-21 in cells to enhance chemotherapy.DNAzyme uses Mn²⁺as cofactor to programmatically degrade nucleic acid hydrogel carriers to achieve accurate delivery of various therapeutic agents.Cell experiments show that the nanoparticles have strong toxicity to lung cancer cells,and can effectively inhibit the growth of tumor in vivo,which has broad prospects in biomedicine.Secondly,this paper utilized the cutting activity of DNAzyme to deliver DNAzyme into cells via RNA nanoflower,so as to realize enhanced gene therapy and photothermal therapy.The nanocomposite particles were designed in a layered structure:RNA hydrogel as an internal scaffold and polydopamine(PDA)as an external coating loaded with Cu²⁺.When targeted by AS1411 at the tumor site,polydopamine induced an increase in the temperature of the tumor site through photothermal conversion under near-infrared radiation.At the same time,increased temperature at the tumor site promoted DNAzyme's ability to cut intracellular early growth reaction-1 RNA(EGR-1 m RNA).Cell experiments showed that the nanoparticles had a highly effective targeted damage effect on breast cancer cells.