Metal-Organic Frameworks Facilitate Nucleic Acids for Multimode Synergistic Therapy of Breast Cancer

Nucleic acid coated photothermal nanoregulator for multiple therapy of drug-resistant breast cancer

Chemotherapy resistance is a leading cause of failure in cancer treatment. A variety of strategies have been investigated to overcome this resistance in cancer therapies. However, the complex microenvironment of tumor cells makes it challenging for any single approach to achieve optimal therapeutic outcomes. In this study, we modified MXene with hyaluronic acid (HA) and coloaded it with doxorubicin (DOX) and the nucleic acid miR489 to address chemotherapy resistance by inhibiting DOX efflux and enabling gene interference. The tumor-targeting capability and biocompatibility of the developed nanosystem, miR489-DOX/Ti3C2@HA-ADH (DTH489), were enhanced through the incorporation of HA. Under near-infrared radiation, MXene not only facilitates photothermal therapy but also reduces the efflux of chemotherapy drugs by down regulating the expression of P-glycoprotein. Additionally, miR489 inhibits epithelial-mesenchymal transition by suppressing the expression of Mothers Against Decapentaplegic Homolog 3, which substantially improves the sensitivity of drug-resistant cancer cells to DOX. In vitro studies confirmed that DTH489 effectively inhibited DOX-resistant breast cancer cells (MCF-7/ADM). Moreover, DTH489 exhibited substantial tumor growth suppression in a mouse model of drug-resistant breast cancer. The results of this research underscore the potential of DTH489 as a multimodal therapeutic platform that effectively reverses chemotherapy resistance in cancer.

Light-Promoted Lysosomal Escape of a Phthalocyanine and Antisense Oligonucleotide-Complexed G-Quadruplex for Dual Photodynamic and Antisense Therapy

Combination therapy has been proven as an effective strategy for cancer treatment. To this end, we report herein a self-assembled nucleic acid-based complex for dual photodynamic and antisense therapy. It contains a nucleolin-targeting As1411-based G-quadruplex platform, a partially hybridized antisense oligonucleotide 4625, which can inhibit the antiapoptotic protein B cell lymphoma-xL inducing apoptotic cell death, and a zinc(II) phthalocyanine (ZnPc)-based photosensitizer held by noncovalent interactions. Through a series of in vitro experiments, we have demonstrated that this DNA complex can be internalized selectively to nucleolin-overexpressed MCF-7 and A549 cells through receptor-mediated endocytosis and is localized in the lysosomes. Upon light irradiation, the photosensitization of ZnPc triggers the formation of reactive oxygen species for cell killing and promotes the lysosomal escape of 4625 for antisense therapy. The combined therapeutic effect can eliminate the cancer cells effectively with a half maximal inhibitory concentration of ca. 0.5 μM.

Smart Stimuli-Responsive Spherical Nucleic Acids: Cutting-Edge Platforms for Biosensing, Bioimaging, and Therapeutics

Spherical nucleic acids (SNAs) with exceptional colloidal stability, multiple modularity, and programmability are excellent candidates to address common molecular delivery-related issues. Based on this, the higher targeting accuracy and enhanced controllability of stimuli-responsive SNAs render them precise nanoplatforms with inestimable prospects for diverse biomedical applications. Therefore, tailored diagnosis and treatment with stimuli-responsive SNAs may be a robust strategy to break through the bottlenecks associated with traditional nanocarriers. Various stimuli-responsive SNAs are engineered through the incorporation of multifunctional modifications to meet biomedical demands with the development of nucleic acid functionalization. This review provides a comprehensive overview of prominent research in this area and recent advancements in the utilization of stimuli-responsive SNAs in biosensing, bioimaging, and therapeutics. For each aspect, SNA nanoplatforms that exhibit responsive behavior to both internal stimuli (including sequence, enzyme, redox reactions, and pH) and external stimuli (such as light and temperature) are highlighted. This review is expected to offer inspiration and guidance strategies for the rational design and development of stimuli-responsive SNAs in the field of biomedicine.

Biomimetic Construction of Degradable DNAzyme-Loaded Nanocapsules for Self-Sufficient Gene Therapy of Pulmonary Metastatic Breast Cancer

Pulmonary metastasis of breast cancer is the major cause of deaths of breast cancer patients, but the effective treatment of pulmonary metastases is still lacking at present. Herein, a degradable biomimetic DNAzyme biocapsule is developed with the poly(ethylenimine) (PEI)-DNAzyme complex encapsulated in a Mn2+/Zn2+-coordinated inositol hexaphosphate (IP6) capsule modified with the cRGD targeting peptide for high-efficiency gene therapy of both primary and pulmonary metastatic breast tumors. This DNAzyme biocapsule is degradable inside acidic lysosomes, leading to the release of DNAzyme and abundant Mn2+/Zn2+ for catalytic cleavage of EGR-1 mRNA. We find that PEI promotes the lysosomal escape of the released DNAzyme. Both in vitro and in vivo experiments demonstrate the apparent downregulation of EGR-1 and Bcl-2 protein expression after treatment with the DNAzyme biocapsule, thereby inducing apoptotic death of tumor cells. We further verify that the DNAzyme biocapsule exhibits potent therapeutic efficacy against both primary and pulmonary metastatic breast tumors with significant inhibition of peri-pulmonary metastasis. This study provides a promising effective strategy for constructing degradable DNAzyme-based platforms with self-supply of abundant metal ion cofactors for high-efficiency gene therapy of metastatic breast cancer.