A Multiple Targeting Nanoprobe for Identifying Cancer Metastatic Sites Based on Detection of Various mRNAs in Circulating Tumor Cells.

Identification of cancer metastatic sites is of importance for adjusting therapeutic interventions and treatment choice. However, identifying the location of metastatic lesions with easy accessibility and high safety is challenging. Here we demonstrate that cancer metastatic sites can be accurately detected by a triple targeting nanoprobe. Through coencapsulating molecular beacons probing a cancer biomarker (CXCR4 mRNA), a lung metastatic biomarker (CTSC mRNA), and a bone metastatic biomarker (JAG1 mRNA), the nanoprobe decorated by SYL3C conjugated hyaluronic acid and ICAM-1 specific aptamer conjugated hyaluronic acid can target diverse phenotyped circulating tumor cells (CTCs) during epithelial-mesenchymal and mesenchymal-epithelial transitions in whole blood for sensitive probing. The detection of CTCs from cancer patients shows that the nanoprobe can provide accurate information to distinguish different cancer metastasis statuses including nonmetastasis, lung metastasis, and bone metastasis. This study proposes an efficient screening tool for identifying the location of distant metastatic lesions via facile blood biopsy.

Probiotic Spore-Based Oral Drug Delivery System for Enhancing Pancreatic Cancer Chemotherapy by Gut-Pancreas-Axis-Guided Delivery.

The chemotherapeutic effectiveness of pancreatic ductal adenocarcinoma (PDAC) is severely hampered by insufficient intratumoral delivery of antitumor drugs. Here, we demonstrate that enhanced pancreatic cancer chemotherapy can be achieved by probiotic spore-based oral drug delivery system via gut-pancreas axis translocation. Clostridium butyricum spores resistant to harsh external stress are extracted as drug carriers, which are further covalently conjugated with gemcitabine-loaded mesoporous silicon nanoparticles (MGEM). The spore-based oral drug delivery system (SPORE-MGEM) migrates upstream into pancreatic tumors from the gut, which increases intratumoral drug accumulation by ∼3-fold compared with MGEM. In two orthotopic PDAC mice models, tumor growth is markedly suppressed by SPORE-MGEM without obvious side effects. Leveraging the biological contact of the gut-pancreas axis, this probiotic spore-based oral drug delivery system reveals a new avenue for enhancing PDAC chemotherapy.

Detection of mRNAs of Ribosomal Protein L15 and E-Cadherin in Living Circulating Tumor Cells at Single Cell Resolution To Study Tumor Heterogeneity.

To study the heterogeneity of circulating tumor cells (CTCs) is of crucial importance to analyze cancer progression and metastasis. However, in situ detection of highly heterogeneous CTCs in peripheral blood still faces an elusive challenge. Here, we show direct detection of two metastasis-related mRNAs of diverse CTCs in whole blood by a triple-targeting nanoprobe. In the nanoprobe, two kinds of molecular beacons, MB1 to detect RPL15 mRNA and MB2 to detect E-cadherin (E-cad) mRNA, are loaded in a highly efficient delivery vector decorated with EpCAM-targeted SYL3C, EGFR-targeted CL4, and CD44-targeted hyaluronic acid chains to specifically deliver MB1/MB2 into epithelial, mesenchymal, and stem CTCs in unprocessed peripheral blood. The numbers of RPL15+ and E-cad+ CTCs are positively correlated with the metastasis stages of cancer patients. This study provides an effective strategy to realize direct observation on diverse metastasis-related genes in living CTCs with different phenotypes to provide accurate information on cancer heterogeneity and metastasis.

In Situ Detection of Nanotoxicity in Living Cells Based on Multiple miRNAs Probed by a Peptide Functionalized Nanoprobe.

The potential toxicity of nanoparticles, especially for clinically applicable ones, has become a critical concern. Technologies that can in situ-evaluate the toxicity of nanoparticles with high sensitivity are urgently needed. In this study, a facile strategy was developed for sensitive detection on the nanotoxicity of nanoparticles with low toxicity or a low dose. A functional nanoprobe loaded with molecular beacons was constructed to realize in situ evaluation of the nanotoxicity through probing multiple miRNAs in nanoparticle-exposed living cells. Being composed of protamine complexed with molecular beacons for miRNA detection and decorated by TAT and KALA peptides, the dual-peptide functionalized nanoprobe can efficiently deliver molecular beacons into living cells to realize the real-time monitoring of early biomarkers (miR-21 and miR-221) to evaluate nanotoxicity. Using mesoporous silica nanoparticles (MSNs) with different surface modifications as typical representatives of low toxic nanoparticles, we demonstrate that our nanoprobe can sensitively detect miRNA changes in cells under diverse exposure conditions, that is, MSN-NH2 exhibits the strongest capability to upregulate miR-21 and miR-221, and the upregulation is exposure dose- and time-dependent. Our approach is much more sensitive as compared with conventional methods to study cytotoxicity such as 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cell morphology observation, and reactive oxygen species (ROS) assay. This study paves a path for effective and facile nanotoxicity evaluation and provides insights into the biological impacts of MSNs.

Precise Detection on Cell-Cell Fusion by a Facile Molecular Beacon-Based Method.

Cell-cell fusion studies provide an experimental platform for evaluating disease progression and investigating cell infection. However, to realize sensitive and quantitative detection on cell-cell fusion is still a challenge. Herein, we report a facile molecular beacon (MB)-based method for precise detection on cell-cell fusion. By transfection of the spike protein (S protein) and enhanced green fluorescent protein (EGFP) in HEK 293 cells, the virus-mimicking fusogenic effector cells 293-S-EGFP cells were constructed to interact with target cells. Before mixing the effector cells with the target cells, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) expression in 293-S-EGFP cells was silenced, and the MB for GAPDH mRNA detection was delivered into the GAPDH silenced 293-S-EGFP cells. Once cell-cell fusion occurred, MB migrated from the GAPDH silenced effector cells to the target cells and hybridized with GAPDH mRNA in the target cells to induce fluorescence emission. The cell-cell fusion can be easily visualized and quantitated by fluorescence microscopy and flow cytometry. The fluorescence intensity is strongly dependent on the number of fused target cells. This MB-based method can easily identify the differences in the cell fusions for various target cells with different angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) expression levels, resulting in dramatically different fluorescence intensities in fused target cells. Our study provides a convenient and efficient quantitative detection approach to study cell-cell fusion.

Nanoparticle-Mediated Inhibition of Mitochondrial Glutaminolysis to Amplify Oxidative Stress for Combination Cancer Therapy.

Selective amplification of reactive oxygen species (ROS) generation in tumor cells has been recognized as an effective strategy for cancer therapy. However, an abnormal tumor metabolism, especially the mitochondrial glutaminolysis, could promote tumor cells to generate high levels of antioxidants (e.g., glutathione) to evade ROS-induced damage. Here, we developed a tumor-targeted nanoparticle (NP) platform for effective breast cancer therapy via combining inhibition of mitochondrial glutaminolysis and chemodynamic therapy (CDT). This NP platform is composed of bovine serum albumin (BSA), ferrocene, and purpurin. After surface decoration with a tumor-targeting aptamer and then intravenous administration, this NP platform could target tumor cells and release ferrocene to catalyze hydrogen peroxide (H2O2) into the hydroxyl radical (·OH) for CDT. More importantly, purpurin could inhibit mitochondrial glutaminolysis to concurrently prevent the nutrient supply for tumor cells and disrupt intracellular redox homeostasis for enhanced CDT, ultimately leading to the combinational inhibition of tumor growth.

A Strategy Based on the Enzyme-Catalyzed Polymerization Reaction of Asp-Phe-Tyr Tripeptide for Cancer Immunotherapy.

Immunotherapy has provided a promising strategy for the treatment of cancers. However, even in tumors with high antigen burdens, the systemic inhibition of the antigen presentation still greatly restricts the application of immunotherapy. Here, we construct a tumor protein-engineering system based on the functional tripeptide, Asp-Phe-Tyr (DFY), which can automatically collect and deliver immunogenetic tumor proteins from targeted cells to immune cells. Through a tyrosinase-catalyzed polymerization, the DFY tripeptide selectively accumulates in tyrosinase high-expressed melanoma cells. Then quinone-rich intermediates are covalently linked with tumor-specific proteins by Michael addition and form tumor protein-carried microfibers that could be engulfed by antigen-presenting cells and exhibited tumor antigenic properties for boosting immune effect. In melanoma cells with deficient antigen presentation, this system can successfully enrich and transport tumor antigen-containing proteins to immune cells. Furthermore, in the in vivo study on murine melanoma, the transdermal delivery of the DFY tripeptide suppressed the tumor growth and the postsurgery recurrence. Our findings provide an avenue for the regulation of the immune system on an organism by taking advantage of certain polymerization reactions by virtue of chemical biology.

Facile Strategy To Enhance Specificity and Sensitivity of Molecular Beacons by an Aptamer-Functionalized Delivery Vector.

To enhance the specificity and sensitivity of molecular beacons (MBs) in detecting mRNA in living tumor cells, we introduced an aptamer (AS1411) to the delivery system of MBs to form an aptamer-decorated nanoprobe (ANP), which was prepared through self-assembly between AS1411-conjugated carboxymethyl chitosan (ACMC) with protamine sulfate (PS)/CaCO3/MB cores. Owing to the specific binding of AS1411 to nucleolin, which is overexpressed in tumor cell membranes and nuclei, an AS1411-decorated MB-delivery system leads to dramatically increased cell uptake of MBs for probing survivin mRNA and thus induces strong intracellular fluorescence emission in targeted tumorous cells and cell nuclei. Furthermore, we demonstrate that ANP can efficiently detect survivin mRNA in mitochondria. In other words, the effective delivery of MBs ensures the precise detection of mRNA distribution in diverse organelles. In addition, we evaluated the efficiency of ANP in probing tumor cells in simulated blood as well as in peripheral blood from a healthy donor and found that the nanoprobe can specifically deliver MBs to tumor cells and identify tumor cells in blood. The targeting delivery system we constructed holds promising applications in precise detection of subcellular distribution of mRNA in living tumor cells as well as in fluorescence-guided cancer detection in liquid biopsy technology. This study provides a facile strategy to effectively improve the specificity and sensitivity of conventional molecular beacons.

Inhibition of Tumor Progression through the Coupling of Bacterial Respiration with Tumor Metabolism.

By leveraging the ability of Shewanella oneidensis MR-1 (S. oneidensis MR-1) to anaerobically catabolize lactate through the transfer of electrons to metal minerals for respiration, a lactate-fueled biohybrid (Bac@MnO2 ) was constructed by modifying manganese dioxide (MnO2 ) nanoflowers on the S. oneidensis MR-1 surface. The biohybrid Bac@MnO2 uses decorated MnO2 nanoflowers as electron receptor and the tumor metabolite lactate as electron donor to make a complete bacterial respiration pathway at the tumor sites, which results in the continuous catabolism of intercellular lactate. Additionally, decorated MnO2 nanoflowers can also catalyze the conversion of endogenous hydrogen peroxide (H2 O2 ) into generate oxygen (O2 ), which could prevent lactate production by downregulating hypoxia-inducible factor-1α (HIF-1α) expression. As lactate plays a critical role in tumor development, the biohybrid Bac@MnO2 could significantly inhibit tumor progression by coupling bacteria respiration with tumor metabolism.

Targeting Delivery of Oligodeoxynucleotides to Macrophages by Mannosylated Cationic Albumin for Immune Stimulation in Cancer Treatment.

To efficiently deliver CpG oligodeoxynucleotides (ODNs) to macrophages for the reversal of cancer-induced immunosuppression, nanoparticles ODN@MCBSA with mannosylated cationic albumin (MCBSA) as a macrophage targeting vector were constructed. Compared with ODN@CBSA with cationic albumin (CBSA) as a vector, ODN@MCBSA exhibited significantly improved cellular uptake mediated by mannose moieties, resulting in significantly enhanced secretion of proflammatory cytokines including IL-12, IL-6, TNF-α, and iNOS. The modulation of macrophages toward the favorable M1 phenotype was confirmed by the upregulated CD80 expression after being treated by ODN delivery systems. In addition to immune cells, the effects of the ODN delivery system on cancerous HeLa cells were also investigated. The results showed that ODN@MCBSA did not affect the overall tumor cell viability. However, enhanced NF-κB, p-Akt, PIK3R3, Fas, and FasL, as well as upregulated caspases were observed in tumor cells, implying the pleiotropic effects on tumor cells. Our study provides a more in-depth understanding on the immunotherapeutic effects of CpG ODNs and highlights the importance of macrophage targeting delivery to minimize the effects on tumor cells. These results indicate that MCBSA could serve as a promising delivery vector of CpG ODNs to macrophages for cancer immunotherapy.

A Dual-Targeting Delivery System for Effective Genome Editing and In Situ Detecting Related Protein Expression in Edited Cells.

One of critical steps in genome editing by CRISPR-Cas9 is to deliver the CRISPR-Cas9 system into targeted cells. In this study, we developed a dual-targeting delivery system based on polymer/inorganic hybrid nanoparticles to realize highly efficient genome editing in targeted tumor cells as well as in situ detection on the related protein expression in edited cells. The CRISPR-Cas9 plasmid for CDK11 knockout was encapsulated in the core of the delivery system composed of protamine sulfate, calcium carbonate, and calcium phosphate by coprecipitation, and functional derivatives of carboxymethyl chitosan (biotinylated carboxymethyl chitosan with biotin ligands and aptamer-incorporated carboxymethyl chitosan with AS1411 ligands) were decorated on the nanovector surface by electrostatic interactions to form the dual-targeting delivery system. On the basis of the tumor cell targeting capability of biotin and AS1411 ligands as well as the nuclear targeting of AS1411, the dual-targeting system can deliver the CRISPR-Cas9 plasmid into the nuclei of tumor cells to realize highly efficient genome editing, resulting in a dramatic decrease (>90%) in CDK11 protein together with the significant downregulation of other proteins involved in tumor development, including an ∼90% decrease in MMP-9, >40% decrease in VEGF, and ∼70% decrease in survivin. Using the same vector, molecular beacons can be easily delivered to edited cell nuclei to in situ detect the mRNA level of related proteins (p53 and survivin as typical examples) and mRNA distribution in subcellular organelles. Our strategy can realize effective genome editing and in situ detection on related protein expression simultaneously.

Switching Apoptosis to Ferroptosis: Metal-Organic Network for High-Efficiency Anticancer Therapy.

Discovering advanced materials for regulating cell death is of great importance in the development of anticancer therapy. Herein, by harnessing the recently discovered oxidative stress regulation ability of p53 and the Fenton reaction inducing capability of metal-organic network (MON), MON encapsulated with p53 plasmid (MON-p53) was designed to eradicate cancer cells via ferroptosis/apoptosis hybrid pathway. After confirming the detailed mechanism of MON-p53 in evoking ferroptosis, we further discovered that MON-p53 mediated a "bystander effect" to further sensitize cancer cells toward the MON-p53 induced ferroptosis. A 75-day anticancer experiment indicated that MON-p53 treatment not only suppressed the tumor growth but also prolonged the life-span of tumor bearing mice. Owing to its ability to promote intracellular oxidative stress, MON-p53 decreased the blood metastasis, lung metastasis, and liver metastasis. As a consequence, discovering methods to induce cell ferroptosis would provide a new insight in designing anticancer materials.

A Metal-Polyphenol Network Coated Nanotheranostic System for Metastatic Tumor Treatments.

As a characteristic trait of most tumor types, metastasis is the major cause of the death of patients. In this study, a photothermal agent based on gold nanorod is coated with metal (Gd3+ )-organic (polyphenol) network to realize combination therapy for metastatic tumors. This nanotheranostic system significantly enhances antitumor therapeutic effects in vitro and in vivo with the combination of photothermal therapy (PTT) and chemotherapy, also can remarkably prevent the invasion and metastasis due to the presence of polyphenol. After the treatment, an 81% decrease in primary tumor volumes and a 58% decrease in lung metastasis are observed. In addition, the good performance in magnetic resonance imaging, computerized tomography, and photothermal imaging of the nanotheranostic system can realize image-guided therapy. The multifunctional nanotheranostic system will find a great potential in diagnosis and treatment integration in tumor treatments, and broaden the applications of PTT treatment.

Tumor Targeting Synergistic Drug Delivery by Self-Assembled Hybrid Nanovesicles to Overcome Drug Resistance.

PURPOSE: To overcome multi-drug resistance (MDR) in tumor chemotherapy, a polymer/inorganic hybrid drug delivery platform with tumor targeting property and enhanced cell uptake efficiency was developed. METHOD: To evaluate the applicability of our delivery platform for the delivery of different drug resistance inhibitors, two kinds of dual-drug pairs (doxorubicin/buthionine sulfoximine and doxorubicin/tariquidar, respectively) were loaded in heparin-biotin/heparin/protamine sulfate/calcium carbonate nanovesicles to realize simultaneous delivery of an anticancer drug and a drug resistance inhibitor into drug-resistant tumor cells. RESULTS: Prepared by self-assembly, the drug loaded hybrid nanovesicles with a mean size less than 210 nm and a negative zeta potential exhibit good stability in serum contained aqueous media. The in vitro cytotoxicity evaluation indicates that hybrid nanovesicles with tumor targeting biotin moieties have an enhanced tumor cell inhibitory effect. In addition, dual-drug loaded hybrid nanovesicles exhibit significantly stronger cell growth inhibition as compared with doxorubicin (DOX) mono-drug loaded nanovesicles due to the reduced intracellular glutathione (GSH) content by buthionine sulfoximine (BSO) or the P-glycoprotein (P-gp) inhibition by tariquidar (TQR). CONCLUSIONS: The tumor targeting nanovesicles prepared in this study, which can simultaneously deliver multiple drugs and effectively reverse drug resistance, have promising applications in drug delivery for tumor treatments. The polymer/inorganic hybrid drug delivery platform developed in this study has good applicability for the co-delivery of different anti-tumor drug/drug resistance inhibitor pairs to overcome MDR. Graphical Abstract A polymer/inorganic hybrid drug delivery platform with enhanced cell uptake was developed for tumor targeting synergistic drug delivery. The heparin-biotin/heparin/protamine sulfate/calcium carbonate nanovesicles prepared in this study can deliver an anticancer drug and a drug resistance inhibitor into drug-resistant tumor cells simultaneously to overcome drug resistance efficiently.

Highly Integrated Nano-Platform for Breaking the Barrier between Chemotherapy and Immunotherapy.

Fighting metastasis is a major challenge in cancer therapy, and stimulation of the immune system is of particular importance in the treatment of metastatic cancers. Here, an integrated theranostic nanoplatform was developed for the efficient treatment of highly metastatic tumors. Versatile functions including "And" logically controlled drug release, prolonged circulation time, tumor targeting, and anti-metastasis were integrated into doxorubicin (DOX) loaded, highly integrated mesoporous silica nanoparticles (DOX@HIMSNs) for a systemic treatment of highly metastatic triple negative breast cancer (TNBC). It was found that the good therapeutic effect of DOX@HIMSN was only partially attributed to its anticancer cytotoxicity. Most importantly, DOX@HIMSN could induce anticancer immune responses including dendritic cell (DC) maturation and antitumor cytokine release. Compared with the traditional tumor chemotherapy, the integrated theranostic nanoplatform we developed not only improved the tumor specific cytotoxicity but also stimulated antitumor immune responses during the treatment.

Programmed Nanococktail for Intracellular Cascade Reaction Regulating Self-Synergistic Tumor Targeting Therapy.

In this work, a ZnO based nanococktail with programmed functions is designed and synthesized for self-synergistic tumor targeting therapy. The nanococktail can actively target tumors via specific interaction of hyaluronic acid (HA) with CD44 receptors and respond to HAase-rich tumor microenvironment to induce intracellular cascade reaction for controlled therapy. The exposed cell-penetrating peptide (R8) potentiates the cellular uptake of therapeutic nanoparticles into targeted tumor cells. Then ZnO cocktail will readily degrade in acidic endo/lysosomes and induce the production of desired reactive oxygen species (ROS) in situ. The destructive ROS not only leads to serious cell damage but also triggers the on-demand drug release for precise chemotherapy, thus achieving enhanced antitumor efficiency synergistically. After tail vein injection of ZnO cocktail, a favorable tumor apoptosis rate (71.2 ± 8.2%) is detected, which is significantly superior to that of free drug, doxorubicin (12.9 ± 5.2%). Both in vitro and in vivo studies demonstrate that the tailor-made ZnO cocktail with favorable biocompatibility, promising tumor specificity, and self-synergistically therapeutic capacity opens new avenues for cancer therapy.

Bioinspired Nano-Prodrug with Enhanced Tumor Targeting and Increased Therapeutic Efficiency.

Nanotechnology-based drug delivery has a great potential to revolutionize cancer treatment by enhancing anticancer drug efficacy and reducing drug toxicity. Here, a bioinspired nano-prodrug (BiNp) assembled by an antineoplastic peptidic derivative (FA-KLA-Hy-DOX), a folate acid (FA)-incorporated proapoptotic peptide (KLAKLAK)(2) (KLA) to doxorubicin (DOX) via an acid-labile hydrozone bond (Hy) is constructed. The hydrophobic antineoplastic agent DOX is efficiently shielded in the core of nano-prodrug. With FA targeting moieties on the surface, the obtained BiNp shows significant tumor-targeting ability and enhances the specific uptake of cancer cells. Upon the trigger by the intracellular acidic microenvironment of endosomes, the antineoplastic agent DOX is released on-demand and promotes the apoptosis of cancer cells. Simultaneously, the liberated FA-KLA can induce the dysfunction of mitochondria and evoke mitochondria-dependent apoptosis. In vitro and in vivo results show that the nano-prodrug BiNp with integrated programmed functions exhibits remarkable inhibition of tumor and achieves a maximized therapeutic efficiency with a minimized side effect.

Self-assembled polymer/inorganic hybrid nanovesicles for multiple drug delivery to overcome drug resistance in cancer chemotherapy.

With the aim to develop a facile strategy to prepare functional drug carriers to overcome multidrug resistance (MDR), we prepared heparin/protamine/calcium carbonate (HP/PS/CaCO3) hybrid nanovesicles with enhanced cell internalization, good serum stability, and pH sensitivity for drug delivery. All the functional components including protamine to improve the cell uptake, heparin to enhance the stability, and CaCO3 to improve drug loading and endow the system with pH sensitivity were introduced to the nanovesicles by self-assembly in an aqueous medium. An antitumor drug (doxorubicin, DOX) and a drug resistance inhibitor (tariquidar, TQR) were coloaded in the nanovesicles during self-assembly preparation of the nanovesicles. The drug loaded nanovesicles, which had a mean size less than 200 nm, exhibited a pH-sensitive drug release behavior. In vitro study was carried out in both nonresistant cells (HeLa and MCF-7) and drug-resistant cancer cells (MCF-7/ADR). Because of the enhanced intracellular and nuclear drug accumulation through effective inhibition of the P-gp efflux transporter, DOX/TQR coloaded nanovesicles showed significantly improved tumor cell inhibitory efficiency, especially for drug-resistant cells. These results suggest the self-assembled nanovesicles have promising applications in multidrug delivery to overcome drug resistance in tumor treatments.

Multifunctional envelope-type mesoporous silica nanoparticles for tumor-triggered targeting drug delivery.

A novel type of cellular-uptake-shielding multifunctional envelope-type mesoporous silica nanoparticle (MEMSN) was designed for tumor-triggered targeting drug delivery to cancerous cells. ß-Cyclodextrin (ß-CD) was anchored on the surface of mesoporous silica nanoparticles via disulfide linking for glutathione-induced intracellular drug release. Then a peptide sequence containing Arg-Gly-Asp (RGD) motif and matrix metalloproteinase (MMP) substrate peptide Pro-Leu-Gly-Val-Arg (PLGVR) was introduced onto the surface of the nanoparticles via host-guest interaction. To protect the targeting ligand and prevent the nanoparticles from being uptaken by normal cells, the nanoparticles were further decorated with poly(aspartic acid) (PASP) to obtain MEMSN. In vitro study demonstrated that MEMSN was shielded against normal cells. After reaching the tumor cells, the targeting property could be switched on by removing the PASP protection layer via hydrolyzation of PLGVR at the MMP-rich tumor cells, which enabled the easy uptake of drug-loaded nanoparticles by tumor cells and subsequent glutathione-induced drug release intracellularly.

Avidin-biotin interaction mediated peptide assemblies as efficient gene delivery vectors for cancer therapy.

Gene therapy offers a bright future for the treatment of cancers. One of the research highlights focuses on smart gene delivery vectors with good biocompatibility and tumor-targeting ability. Here, a novel gene vector self-assembled through avidin-biotin interaction with optimized targeting functionality, biotinylated tumor-targeting peptide/avidin/biotinylated cell-penetrating peptide (TAC), was designed and prepared to mediate the in vitro and in vivo delivery of p53 gene. TAC exhibited efficient DNA-binding ability and low cytotoxicity. In in vitro transfection assay, TAC/p53 complexes showed higher transfection efficiency and expression amount of p53 protein in MCF-7 cells as compared with 293T and HeLa cells, primarily due to the specific recognition between tumor-targeting peptides and receptors on MCF-7 cells. Additionally, by in situ administration of TAC/p53 complexes into tumor-bearing mice, the expression of p53 gene was obviously upregulated in tumor cells, and the tumor growth was significantly suppressed. This study provides an alternative and unique strategy to assemble functionalized peptides, and the novel self-assembled vector TAC developed is a promising gene vector for cancer therapy.