Self-assembled nanocomplex between polymerized phenylboronic acid and doxorubicin for efficient tumor-targeted chemotherapy

Regulating Drug Release Performance of Acid-Triggered Dimeric Prodrug-Based Drug Self-Delivery System by Altering Its Aggregation Structure

Dimeric prodrugs have been investigated intensely as carrier-free drug self-delivery systems (DSDSs) in recent decades, and their stimuli-responsive drug release has usually been controlled by the conjugations between the drug molecules, including the stimuli (pH or redox) and responsive sensitivity. Here, an acid-triggered dimeric prodrug of doxorubicin (DOX) was synthesized by conjugating two DOX molecules with an acid-labile ketal linker. It possessed high drug content near the pure drug, while the premature drug leakage in blood circulation was efficiently suppressed. Furthermore, its aggregation structures were controlled by fabricating nanomedicines via different approaches, such as fast precipitation and slow self-assembly, to regulate the drug release performance. Such findings are expected to enable better anti-tumor efficacy with the desired drug release rate, beyond the molecular structure of the dimeric prodrug.

Disulfide/α-Amide-Bridged Doxorubicin Dimeric Prodrug: Effect of Aggregation Structures on pH/GSH Dual-Triggered Drug Release

Disulfide bonding has attracted intense interest in the tumor intracellular microenvironment-activated drug delivery systems (DDSs) in the last decades. Although various molecular structures of redox-responsive disulfide-containing DDSs have been developed, no investigation was reported on the effect of aggregation structures. Here, the effect of aggregation structures on pH/GSH dual-triggered drug release was investigated with the simplest pH/GSH dual-triggered doxorubicin-based drug self-delivery system (DSDS), the disulfide/α-amide-bridged doxorubicin dimeric prodrug (DDOX), as a model. By fast precipitation or slow self-assembly, DDOX nanoparticles were obtained. With similar diameters, they exhibited different pH/GSH dual-triggered drug releases, demonstrating the effect of aggregation structures. The π-π stacking in different degrees was revealed by the UV-vis, fluorescence, and BET analysis of the DDOX nanoparticles. The effect of the π-π stacking between the dimeric prodrug and its activated products on drug release was also explored with the molecular simulation approach. The finding opens new ideas in the design of high-performance DDSs for future precise tumor treatment.

Magnetic coagulation and flocculation of kaolin suspension using Fe3O4 with plant polyphenol self-assembled flocculants

In this work, magnetic flocculant (Fe3O4@PP) was synthesized using plant polyphenol (PP) as a shaping ligand via in situ self-assembly. Characterization results revealed that Fe3O4@PP exhibited uniform particle size and excellent dispersibility with PP coating amount of 16.4 %. Experimental results suggested that Fe3O4@PP showed excellent turbidity removal efficiency in a wide pH range (3.0-10) and initial turbidity range (50-2000 NTU). Under the optimal conditions, Fe3O4@PP achieved 95.2 % of turbidity removal for simulated kaolin suspension and 96.9 % for actual wastewater. Fe3O4@PP exhibited excellent recycling and reusability properties, with high recycling efficiency of 93.3 % even after the fifth cycle. Microscopic observation revealed the formation process of magnetic flocs, involving particle aggregation, chain and cluster formation, and dense network aggregate formation. The structural characteristics and size of magnetic flocs were found to be significantly influenced by the combined effects of magnetic force, electric charge, van der Waals force, and functional groups on the surface of PP. The extended Deryaguin-Landau-Verwey-Overbeek models indicated that magnetic interactions were the primary mechanism for magnetic flocculation, accompanied by charge neutralization, adsorption bridging, sweeping, and net trapping.

Real-time SERS monitoring anticancer drug release along with SERS/MR imaging for pH-sensitive chemo-phototherapy

In situ and real-time monitoring of responsive drug release is critical for the assessment of pharmacodynamics in chemotherapy. In this study, a novel pH-responsive nanosystem is proposed for real-time monitoring of drug release and chemo-phototherapy by surface-enhanced Raman spectroscopy (SERS). The Fe3O4@Au@Ag nanoparticles (NPs) deposited graphene oxide (GO) nanocomposites with a high SERS activity and stability are synthesized and labeled with a Raman reporter 4-mercaptophenylboronic acid (4-MPBA) to form SERS probes (GO-Fe3O4@Au@Ag-MPBA). Furthermore, doxorubicin (DOX) is attached to SERS probes through a pH-responsive linker boronic ester (GO-Fe3O4@Au@Ag-MPBA-DOX), accompanying the 4-MPBA signal change in SERS. After the entry into tumor, the breakage of boronic ester in the acidic environment gives rise to the release of DOX and the recovery of 4-MPBA SERS signal. Thus, the DOX dynamic release can be monitored by the real-time changes of 4-MPBA SERS spectra. Additionally, the strong T2 magnetic resonance (MR) signal and NIR photothermal transduction efficiency of the nanocomposites make it available for MR imaging and photothermal therapy (PTT). Altogether, this GO-Fe3O4@Au@Ag-MPBA-DOX can simultaneously fulfill the synergistic combination of cancer cell targeting, pH-sensitive drug release, SERS-traceable detection and MR imaging, endowing it great potential for SERS/MR imaging-guided efficient chemo-phototherapy on cancer treatment.

Phenylboronic acid-modified polymaleic anhydride-F127 micelles for pH-activated targeting delivery of doxorubicin

Phenylboronic acid (PBA) is a tumor-targeting molecule which selectively recognizes sialic acid (SA) overexpressed in tumors. In the study, PBA, F127 and ethanolamine were conjugated with poly(maleic anhydride) by one-step reaction to form amphiphilic polymer for doxorubicin encapsulation. Two drug-carrying micelles with different mass ratio of polymer to drug were prepared by dialysis method to study effect of PBA on doxorubicin release, tumor-targeting and antitumor activity. The study results showed that doxorubicin release from the formulations was acid-sensitive and affected by the polymer dosage, and its acid-induced release behavior improved its insertion into DNA base pairs. Formulation with high polymer dosage showed better tumor targeting and antitumor activity, and activity of inhibiting HepG2 with higher content of SA-containing glycosphingolipids was higher than that of anti-B16. In vivo studies on the activity of B16-bearing mice showed that the doxorubicin-loaded micelles could inhibit the tumor growth and were safer than free doxorubicin. Thus, the PBA-modified nano-polymer micelles have potential biomedical applications due to their nanostructure and tumor-targeting ability.

Dual-targeted and controlled release delivery of doxorubicin to breast adenocarcinoma: In vitro and in vivo studies

Doxorubicin (DOX) is a chemotherapeutic drug that belongs to the anthracyclines family. Cardiotoxicity is one of the main limiting factor of prescribing DOX. To reduce its side effects and enhance the drug delivery to the targeted tissues, we aimed to establish a new targeted and controlled release drug delivery system for treatment of breast cancer. In this article, we tried to synthesize a new nanoplatform consisted of DOX conjugate with hydrazide and disulfide bonds to the hyaluronic acid (HA). Firstly, 4,4'-Dithiodibutyric acid (DTBH) was conjugated with HA. Then, 3-aminophenyl boronic acid monohydrate (APBA) was conjugated with DTBH-HA. Subsequently, DOX was added to DTBH-HA-APBA. HA is a natural polymer with the ability to target CD44, a cell surface adhesion receptor, which are highly overexpressed on the surface of variety of cancer cells. Other targeting agent, APBA can target sialic acid on the cancer cells surface and improve the tumor uptake. Formation of The DTBH-HA-APBA conjugate was confirmed by proton nuclear magnetic resonance (¹H-NMR) spectroscopy. Scanning emission electron microscopy (SEM) images of the DOX-DTBH-HA-APBA displayed a spherical shape with an average diameter of about 70 nm. In vitro drug release study showed considerably different release pattern of DOX from the formulation at acidic pH (5.4) which was higher than normal pH (7.4). Cellular uptake and cellular cytotoxicity analysis were examined in human breast adenocarcinoma cell line (MCF-7) and mouse breast cancer cells (4T1) as positive cell lines and Chinese Hamster Ovary cells (CHO) as negative cell line. Results confirmed that there is a remarkable difference between dual-targeted (DOX-DTBH-HA-APBA) and single targeted (DOX-DTBH-HA) formulations in both positive cell lines regarding internalization and cytotoxicity. In vivo studies indicated that dual-targeted formulation has the best efficacy with minimum side effects in mouse model. Fluorescence imaging of organs revealed that DOX-DTBH-HA-APBA showed greater DOX accumulation compared with DOX-DTBH-HA and free DOX in tumor site. Also, pathological evaluation indicated that there is no observable cardiotoxicity with final formulation.

Determination of the Influence of Various Factors on the Character of Surface Functionalization of Copper(I) and Copper(II) Oxide Nanosensors with Phenylboronic Acid Derivatives

In this work, we attempt to determine the influence of the oxidation state of copper [Cu(I) vs Cu(II)], the nature of the interface (solid/aqueous vs solid/air), the incubation time, and the structure of N-substituted phenylboronic acids (PBAs) functionalizing the surface of copper oxide nanostructures (NSs) on the mode of adsorption. For this purpose, 4-[(N-anilino)(phosphono)-S-methyl]phenylboronic acid (1-PBA) and its two analogues (2-PBA and bis{1-PBA}) and the copper oxide NSs were synthesized in a surfactant-/ion-free solution via a synthetic route that allows controlling the size and morphology of NSs. The NSs were characterized by scanning electron microscopy, ultraviolet-visible spectroscopy, Raman spectroscopy, and X-ray diffraction, which confirmed the formation of spherical Cu2O nanoparticles (Cu2ONPs) with a size of 1.5 μm to 600 nm crystallized in a cubic cuprite structure and leaf-like CuO nanostructures (CuONSs) with dimensions of 80-180 nm in width and 400-700 nm in length and crystallized in a monoclinic structure. PBA analogues were deposited on the surface of the copper oxide NSs, and adsorption was investigated using surface-enhanced Raman spectroscopy (SERS). The changes in the orientation of the molecule relative to the substrate surface caused by the abovementioned factors were described, and the signal enhancement on the copper oxide NSs was determined. This is the first study using vibrational spectroscopy for these compounds.

Phenylboronic acid-based core-shell drug delivery platform clasping 1,3-dicarbonyl compounds by a coordinate interaction

Along with the successful commercialization of chemotherapeutics, such as doxorubicin and paclitaxel, numerous natural compounds have been investigated for clinical applications. Recently, curcumin (CUR), a natural compound with various therapeutic effects, has attracted attention for cancer immunotherapy. Most chemotherapeutics, however, have poor water solubility due to their hydrophobicity, which makes them less suited to biomedical applications; CUR is no exception because of its low bioavailability and extremely high hydrophobicity. In the present study, we developed an easy but effective strategy using the interaction between the 1,3-dicarbonyl groups of drugs and phenylboronic acid (PBA) to solubilize hydrophobic drugs. First, we verified the coordinate interaction between 1,3-dicarbonyl and PBA using 3,5-heptanedione as a model compound, followed by CUR as a model drug. A PBA-grafted hydrophilic polymer was used to form a nanoconstruct by coordination bonding with CUR, which then made direct administration of the nanoparticles possible. The nanoconstruct exhibited remarkable loading capability, uniform size, colloidal stability, and pH-responsive drug release, attributed to the formation of core-shell nanoconstructs by coordinate interaction. The therapeutic nanoconstructs successfully showed both chemotherapeutic and anti-PD-L1 anticancer effects in cellular and animal models. Furthermore, we demonstrated the applicability of this technique to other 1,3-dicarbonyl compounds. Overall, our findings suggest a facile, but expandable strategy by applying the coordinate interaction between 1,3-dicarbonyl and PBA, which enables high drug loading and stimuli-responsive drug release.

Bio-Nanocarriers for Lung Cancer Management: Befriending the Barriers

Lung cancer is a complex thoracic malignancy developing consequential to aberrations in a myriad of molecular and biomolecular signaling pathways. It is one of the most lethal forms of cancers accounting to almost 1.8 million new annual incidences, bearing overall mortality to incidence ratio of 0.87. The dismal prognostic scenario at advanced stages of the disease and metastatic/resistant tumor cell populations stresses the requisite of advanced translational interdisciplinary interventions such as bionanotechnology. This review article deliberates insights and apprehensions on the recent prologue of nanobioengineering and bionanotechnology as an approach for the clinical management of lung cancer. The role of nanobioengineered (bio-nano) tools like bio-nanocarriers and nanobiodevices in secondary prophylaxis, diagnosis, therapeutics, and theranostics for lung cancer management has been discussed. Bioengineered, bioinspired, and biomimetic bio-nanotools of considerate translational value have been reviewed. Perspectives on existent oncostrategies, their critical comparison with bio-nanocarriers, and issues hampering their clinical bench side to bed transformation have also been summarized.

Polymer-Based Dual-Responsive Self-Emulsifying Nanodroplets as Potential Carriers for Poorly Soluble Drugs

A biodegradable amphiphilic liquid polymer was designed to form self-emulsifying nanodroplets in water for delivering poorly soluble drugs. The polymer was composed of multiple short blocks of poly(ethylene glycol) (PEG) and poly(caprolactone) (PCL) connected through acid-labile acetal linkages. With an overall average molecular weight of over 18 kDa, the polymer remained as a viscous liquid under room and physiological temperatures. Dispersing the polymer in an aqueous buffer gave rise to highly stable micelle-like nanodroplets with an average size of approximately 15-20 nm. The nanodroplet dispersions underwent reversible temperature-sensitive aggregation with cloud points ranging from 45 to 50 °C, depending on polymer concentration. Nuclear magnetic resonance (NMR) and dynamic light scattering analyses revealed that while the nanodroplets were stable at pH 7.4 for several days, hydrolysis of the acetal linkages in the polymer backbone was much accelerated under mildly acidic pH 5.0, resulting in the formation of large microdroplets. Nile red (NR), a poorly water-soluble fluorophore, can be solubilized in the nanodroplets, and efficient intracellular delivery of NR was achieved. The hydrophobic indocyanine green (ICG) was also encapsulated in the nanodroplets. Near-infrared (NIR) fluorescence imaging and in vivo biocompatibility of the ICG-loaded nanodroplets were demonstrated in mice. In summary, the self-emulsifying nanodroplets of amphiphilic liquid polymer would be a promising material system for poorly soluble drug delivery and imaging in vivo.

Phenylboronic acid conjugated to doxorubicin nanocomplexes as an anti-cancer drug delivery system in hepatocellular carcinoma

Anti-cancer strategies using nanocarrier systems have been explored in a variety of cancers; these systems can easily be incorporated into tumors via the enhanced permeability and retention (EPR) effect leading to enhanced anti-tumor activity while reducing systemic toxicity by specific tumor-targeting. The prognosis of hepatocellular carcinoma (HCC) is extremely poor when the condition is diagnosed at the unresectable stage as treatment options are limited. In order to improve the treatment of cancer and the overall anti-cancer effect, polymerized phenylboronic acid conjugated doxorubicin (pPBA-Dox) nanocomplexes were generated, and conjugated doxorubicin, which is conventionally used in HCC. The nanocomplexes exhibited enhanced anti-tumor activity via tumor-specific targeting in the subcutaneous and orthotopic HCC syngeneic mice tumor model, implying that the nanocomplexes facilitate the targeted Dox delivery to liver cancer in which the sialic acid is over-expressed. Therefore, this study provides insight into the novel targeted therapy using the nanocomplexes for the treatment of HCC.

Polymeric Nanoparticles Controlled by On-Chip Self-Assembly Enhance Cancer Treatment Effectiveness

Nanoparticle (NP)-based drug delivery systems or nanomedicines have broadened the horizon of translational research for decades. Conventional bulk mixing synthesis methods have impeded successful clinical translations of nanomedicines due to the limited ability of the controlled, scalable production with high uniformity. Herein, an on-chip preparation of self-assembled, drug-encapsulated polymeric NPs is presented for their improved uniformity and homogeneity that results in enhanced anti-cancer effect in vitro and in vivo. The NPs are formulated through rapid convective mixing of two aqueous solutions of a hydrophilic polymer and an anti-cancer drug, doxorubicin (DOX), in the swirling microvortex reactor (SMR). Compared to conventional bulk-mixed NPs (BMPs), the microvortex-synthesized NPs (MVPs) exhibit narrower size distributions and better size tunability. It is found that the improved uniformity and homogeneity of the MVPs not only enhance cellular uptake and anti-cancer effect with pH-responsive drug release in vitro, but also result in an improved tumor regression and decreased side effects at off-targeted organs in vivo. The findings demonstrate that uniformly designed NPs with more homogeneous properties can induce a significant enhancement of an anti-cancer effect in vivo. The results show the potential of a high-speed on-chip synthesis as a scalable manufacturing platform for reliable clinical translations of nanomedicines.

Phenylboronic acid-functionalized F127-oligochitosan conjugate micelles for doxorubicin encapsulation

Doxorubicin shows good anticancer activity, but poor pharmacokinetic property and high organ toxicity restrict its clinical application. The synthesized phenylboronic acid-modified F127-chitosan conjugate was used to prepare doxorubicin-loaded micelles through dialysis method. The physicochemical properties of the doxorubicin-loaded micelles were characterized. These micelles were further evaluated for in vitro release/cytotoxicity, in vivo activity/biosafety, and pharmacokinetic studies. in vitro release experiment demonstrated that the release of doxorubicin from drug-loaded micelles was pH-dependent. in vitro cytotoxic study showed that the introduction of phenylboronic acid resulted in lower IC₅₀ against B16 cells than that in non-modified F127-chitosan micelles group, and the doxorubicin-loaded micelles displayed lower in vitro activity against B16, A549, and HT-29 cells than free doxorubicin did. However, in vivo experiments confirmed that the doxorubicin-loaded micelles were safe for mouse main organs, obviously improved pharmacokinetic parameters of doxorubicin in rat and achieved comparable inhibition of tumor growth with no animal death in B16-bearing mice models throughout the experiment when compared with free doxorubicin. The phenylboronic acid-sialic acid interaction and pH-sensitive drug release might play important roles in increased tumor targeting and therapeutic effect of the doxorubicin-loaded micelles.

Tannic acid-based nanogel as an efficient anti-inflammatory agent

Biologically produced reactive oxygen species (ROS) are important signaling molecules in the human body. Despite their importance under normal conditions, abnormal overproduction of ROS under unbalanced or irregular homeostasis can cause severe inflammatory diseases. Various antioxidants have been developed in the biomedical field to resolve high levels of ROS; however, high doses of natural antioxidants such as polyphenol can induce side effects on health. Further, synthetic antioxidants are still controversial in regards to their safety and their complicated synthesis. Inspired from our previous work, a nitric oxide-scavenging nanogel designed for treating rheumatoid arthritis, we report herein a biocompatible tannic acid (TA)-based nanogel as an effective ROS scavenger. A polymeric phenylboronic acid-tannic acid nanogel (PTNG) was prepared by simply mixing through to the formation of phenylboronic ester bonds between polymeric phenylboronate and TA. We focused on the reaction of phenylboronic ester with H₂O₂, which readily consumes H₂O₂ molecules, and applied it as an antioxidant. In addition, TA is a well-known antioxidant, specifically a free radical scavenger; thus, we expected combinatory ROS scavenging effects for PTNG. Various ROS scavenging assays revealed the significant antioxidant effects of PTNG. Under an induced inflammation model in vitro, our PTNG showed high biocompatibility as well as strong anti-inflammatory effects. Furthermore, in the zymosan-induced peritonitis mouse model, a representative acute inflammation model in vivo, PTNG reduced significant neutrophil recruitment and pro-inflammatory cytokines, indicating successful alleviation of inflammation. On the basis of these results, we suggest that PTNG has great potential as an antioxidant and should find application in the treatment of further ROS-overproducing inflammatory diseases.

Drug-loaded titanium dioxide nanoparticle coated with tumor targeting polymer as a sonodynamic chemotherapeutic agent for anti-cancer therapy

Sonodynamic therapy utilizes ultrasound (US)-responsive generation of reactive oxygen species (ROS) from sonosensitizer, and it is a powerful strategy for anti-cancer treatment in combination with chemotherapy. Herein, we report a precisely designed sonodynamic chemotherapeutics which exhibits US-responsive drug release via ROS generation from co-loaded sono-sensitizer. Doxorubicin (DOX)-coordinated titanium dioxide nanoparticles (TNPs) were encapsulated with polymeric phenyboronic acid (pPBA) via phenylboronic ester bond between pPBA and DOX. Loaded DOX was readily released under US irradiation due to the ROS-cleavable characteristics of phenylboronic ester bond. The size of nanoparticles was around 200 nm, and DOX was released by ROS generated under US irradiation. Tumor targeting by PBA moiety, intracellular ROS generation, and combined therapeutic effect against tumor cells were confirmed in vitro. Finally, we demonstrated high tumor accumulation and efficient tumor growth inhibition in tumor-bearing mice under US irradiation, which revealed potential as a multi-functional agent for sonodynamic chemotherapy.

The capability of nonlinear optical characteristics as a predictor for cellular uptake of nanoparticles and cell damage

Current methods for determining the cellular effects of a treatment modality need expensive materials and much time to provide a researcher with results. The aim of this study was to evaluate the potential of nonlinear optical characteristics of cancer cells using Z-scan technique to monitor the level of cellular uptake and cell damage caused by a nanotechnology based treatment modality. Two nanocomplexes were synthesized and characterized. The first one was made of alginate hydrogel co-loaded with cisplatin and gold nanoparticles (AuNPs) named as ACA nanocomplex. The second one, named as AA nanocomplex, was the same as ACA, but without cisplatin and this AA nanocomplex was considered as the control for ACA. Different groups of CT26 mouse colon cancer cell line received various treatments of cisplatin, ACA, and AA nanocomplexes and then the samples were prepared for Z-scan studies. The MTT assay was used to evaluate the cytotoxicity induced by different treatment modalities. Transmission electron microscopy (TEM) and inductively coupled plasma-mass spectrometry (ICP-MS) were used for qualitative and quantitative assessments of the level of AuNPs cellular uptake. The trend of nonlinear optical properties changes for treated cells was in agreement with MTT, TEM and ICP-MS results. Z-scan technique was able to successfully indicate the occurrence of cell damage. It was also capable to determine the intensity of cell damage induced by ACA nanocomplex in comparison to free cisplatin. Furthermore, Z-scan results showed that it was able to discriminate the differences of optical properties of the cells incubated with ACA nanocomplex for various incubation times. Nonlinear optical characteristics of a cell may be considered as a reliable indicator to predict the level of cellular effects induced by a nanotechnology based treatment modality. The protocol suggested in this article does not waste materials, not take much time to provide the results, and it is inexpensive technique.

A cyotosol-selective nitric oxide bomb as a new paradigm of an anticancer drug

Dual pH and redox-sensitive polymeric NO delivery micelles act as a cytosol-selective NO bomb for efficient anticancer therapy.

Recent Development of pH-Responsive Polymers for Cancer Nanomedicine

Cancer remains a leading cause of death worldwide with more than 10 million new cases every year. Tumor-targeted nanomedicines have shown substantial improvements of the therapeutic index of anticancer agents, addressing the deficiencies of conventional chemotherapy, and have had a tremendous growth over past several decades. Due to the pathophysiological characteristics that almost all tumor tissues have lower pH in comparison to normal healthy tissues, among various tumor-targeted nanomaterials, pH-responsive polymeric materials have been one of the most prevalent approaches for cancer diagnosis and treatment. In this review, we summarized the types of pH-responsive polymers, describing their chemical structures and pH-response mechanisms; we illustrated the structure-property relationships of pH-responsive polymers and introduced the approaches to regulating their pH-responsive behaviors; we also highlighted the most representative applications of pH-responsive polymers in cancer imaging and therapy. This review article aims to provide general guidelines for the rational design of more effective pH-responsive nanomaterials for cancer diagnosis and treatment.

Enhanced uptake of plasmid at boronic acid decorated linear polyethylenimines results in higher transfection efficiency

High molecular weight polyethylenimines (PEIs) are considered as gold standard for transfection studies; however, cytotoxicity associated with branched ones and lower charge density on linear PEIs as well as lower uptake of the resulting deoxyribonucleic acid (DNA) complexes have limited their applications in clinical studies. In order to address these concerns and improve the uptake efficiency of the DNA complexes of linear polyethylenimine (25 kDa), the polymer was grafted with variable amounts of butylboronic acid to obtain a small series of linear polyethylenimine-butylboronic acid polymers. These modified polymers were allowed to interact with plasmid DNA and the resulting complexes were characterized by physicochemical techniques. Dynamic light scattering data showed the formation of nanosized complexes with positive zeta potential values. Furthermore, when these complexes were evaluated in vitro, they not only showed enhanced cell viability but also exhibited higher transfection efficiency as compared to native linear and branched PEIs and a commercially available standard transfection reagent, Lipofectamine 2000.

Functional-DNA-Driven Dynamic Nanoconstructs for Biomolecule Capture and Drug Delivery

The discovery of sequence-specific hybridization has allowed the development of DNA nanotechnology, which is divided into two categories: 1) structural DNA nanotechnology, which utilizes DNA as a biopolymer; and 2) dynamic DNA nanotechnology, which focuses on the catalytic reactions or displacement of DNA structures. Recently, numerous attempts have been made to combine DNA nanotechnologies with functional DNAs such as aptamers, DNAzymes, amplified DNA, polymer-conjugated DNA, and DNA loaded on functional nanoparticles for various applications; thus, the new interdisciplinary research field of "functional DNA nanotechnology" is initiated. In particular, a fine-tuned nanostructure composed of functional DNAs has shown immense potential as a programmable nanomachine by controlling DNA dynamics triggered by specific environments. Moreover, the programmability and predictability of functional DNA have enabled the use of DNA nanostructures as nanomedicines for various biomedical applications, such as cargo delivery and molecular drugs via stimuli-mediated dynamic structural changes of functional DNAs. Here, the concepts and recent case studies of functional DNA nanotechnology and nanostructures in nanomedicine are reviewed, and future prospects of functional DNA for nanomedicine are indicated.