Self-assembled Nucleic Acids-polymer Nanoparticles For Cancer Gene Therapy Using In-situ Rolling Circle Amplification

Nanomedicine has shown unprecedented potential for cancer theranostics.Nucleic acid nanomedine is a particular interesting class of nanomedicines that is promising for cancer therapy.Nucleic acid(e.g.DNA and RNA)nanomedicines are of special interest for combination therapy with chemotherapeutics,photothermal therapy,and immunotherapy,et al.Given the structural programmability and versatile therapeutic functionalities(e.g.small interfering RNA,short hairpin RNA,immunomodulatory DNA/RNA)of nucleic acids,nucleic acid nanomedicines are excellent platforms for codelivery of nucleic acid and other therapeutics in cancer therapy.Combination therapy has long been practiced in the clinic and will certainly further potentiate nucleic acid nanomedicines in cancer therapy.Remarkably,nucleic acid nanomedicines provide an excellent platform to co-deliver nucleic acid therapeutics with other synergistic drugs for combination cancer therapy.However,current nanotechnologies to construct such nucleic acid nanomedicines,which rely on chemical conjugation or physical complexation of nucleic acids with chemotherapeutics,have restrained their clinical translation due to limitations such as low drug loading efficiency and poor biostability.Herein,we developed versatile nucleic acid nanomedicine platform for co-delivery of nucleic acid and other therapeutic strategies for cancer treatment.We first designed a gold nanorod embedded large-pore mesoporous organosilica(GNR@LPMO)nanoplatform for gene and photothermal cooperative therapy of triple negative breast cancer(TNBC).The synthesized GNR@LPMOs possess a uniform size(175 nm),high surface area(631 m2 g-1),large pore size,excellent photothermal efficiency,and good biocompatibility.Thanks to the large-pore mesoporous organosilica layer,the GNR@LPMO nanoplatforms display much higher loading capacity of siRNA compared with traditional liposome and bare gold nanorods.Thus,functional siRNA can be efficiently delivered into TNBC cells by GNR@LPMOs,causing much higher cell apoptosis through knocking down the PLK1 proteins.By combining the effective gene delivery and photothermal abilities,the GNR@LPMO nanoplatforms are further used for gene and photothermal cooperative therapy of TNBC,which induce a 15 fold higher mice tumor inhibition rate than sole therapy modality,indicating the potential clinical use of this novel nanoplarform in treating TNBC.Besides,in situ rolling circle transcription is applied to synthesize short hairpin RNA on amphiphilic DNA-polylactide(PLA)micelles.Core-shell PLA@poly-shRNA structures that codeliver a high payload of doxorubicin(Dox)and multidrug resistance protein 1(MDR1)targeted shRNA for MDR breast cancer therapy are developed.DNA-PLA conjugates are first synthesized,which then self-assemble into amphiphilic DNA-PLA micelles;next,using the conjugated DNA as a promoter,poly-shRNA is synthesized on DNA-PLA micelles via RCT,generating PLA@poly-shRNA microflowers;and finally,mimcroflowers are electrostatically condensed into nanoparticles using biocompatible and multifunctional poly(ethylene glycol)-grafted polypeptides(PPT-g-PEG).These PLA@poly-shRNA@PPT-g-PEG nanoparticles are efficiently delivered into MDR breast cancer cells and accumulated in xenograft tumors,leading to MDR1 silencing,intracellular Dox accumulation,potentiated apoptosis,and enhanced tumor therapeutic efficacy.Overall,this nanomedicine platform is promising to codeliver anticancer nucleic acid therapeutics and chemotherapeutics.Based on these strategies,we also developed nucleic acid nanovaccine using in situ rolling circle amplification for co-delviery of both adjuvants and antigens.These nanovaccines were prepared by 1)self assembly of amphiphil Primer-PEG-PLA conjugates in water,2)polymerization of CpG microparticles on the surface of Primer-PEG-PLA nanoparticles,3)loading adjuvant and tumor specific neoantigen,and condensing CpG microparticles into nanovaccines.The novel nanovaccines synergistically activated APCs for sustained antigen presentation and significantly inhibited the progression of antigen specific tumors.We designed several nucleic acids based nanoplatfoms for co-delivery of nucleic acids and other therapeutics.These versatile nanoplatforms will combine gene therapy and other therapeutic strategies,and effectively deliver the therapeutic agents to tumors or other functional tissues.