Bottom-Up Fabrication of Nanopatterned Polymers on DNA Origami by In Situ Atom-Transfer Radical Polymerization

Structural stability of DNA origami nanostructures in organic solvents

DNA origami nanostructures have attracted significant attention as an innovative tool in a variety of research areas, spanning from nanophotonics to bottom-up nanofabrication. However, the use of DNA origami is often restricted by their rather limited structural stability in application-specific conditions. The structural integrity of DNA origami is known to be superstructure-dependent, and the integrity is influenced by various external factors, for example cation concentration, temperature, and presence of nucleases. Given the necessity to functionalize DNA origami also with non-water-soluble entities, it is important to acquire knowledge of the structural stability of DNA origami in various organic solvents. Therefore, we herein systematically investigate the post-folding DNA origami stability in a variety of polar, water-miscible solvents, including acetone, ethanol, DMF, and DMSO. Our results suggest that the structural integrity of DNA origami in organic solvents is both superstructure-dependent and dependent on the properties of the organic solvent. In addition, DNA origami are generally more resistant to added organic solvents in folding buffer compared to that in deionized water. DNA origami stability can be maintained in up to 25-40% DMF or DMSO and up to 70-90% acetone or ethanol, with the highest overall stability observed in acetone. By rationally selecting both the DNA origami design and the solvent, the DNA origami stability can be maintained in high concentrations of organic solvents, which paves the way for more extensive use of non-water-soluble compounds for DNA origami functionalization and complexation.

Engineered Bio-Based Hydrogels for Cancer Immunotherapy

Immunotherapy represents a revolutionary paradigm in cancer management, showcasing its potential to impede tumor metastasis and recurrence. Nonetheless, challenges including limited therapeutic efficacy and severe immune-related side effects are frequently encountered, especially in solid tumors. Hydrogels, a class of versatile materials featuring well-hydrated structures widely used in biomedicine, offer a promising platform for encapsulating and releasing small molecule drugs, biomacromolecules, and cells in a controlled manner. Immunomodulatory hydrogels present a unique capability for augmenting immune activation and mitigating systemic toxicity through encapsulation of multiple components and localized administration. Notably, hydrogels based on biopolymers have gained significant interest owing to their biocompatibility, environmental friendliness, and ease of production. This review delves into the recent advances in bio-based hydrogels in cancer immunotherapy and synergistic combinatorial approaches, highlighting their diverse applications. It is anticipated that this review will guide the rational design of hydrogels in the field of cancer immunotherapy, fostering clinical translation and ultimately benefiting patients.

A DNA/Upconversion Nanoparticle Complex Enables Controlled Co-Delivery of CRISPR-Cas9 and Photodynamic Agents for Synergistic Cancer Therapy

Photodynamic therapy (PDT) depends on the light-irradiated exciting of photosensitizer (PS) to generate reactive oxygen species (ROS), which faces challenges and limitations in hypoxia and antioxidant response of cancer cells, and limited tissue-penetration of light. Herein, a multifunctional DNA/upconversion nanoparticles (UCNPs) complex is developed which enables controlled co-delivery of CRISPR-Cas9, hemin, and protoporphyrin (PP) for synergistic PDT. An ultralong single-stranded DNA (ssDNA) is prepared via rolling circle amplification (RCA), which contains recognition sequences of single guide RNA (sgRNA) for loading Cas9 ribonucleoprotein (RNP), G-quadruplex sequences for loading hemin and PP, and linker sequences for combining UCNP. Cas9 RNP cleaves the antioxidant regulator nuclear factor E2-related factor 2 (Nrf2), improving the sensitivity of cancer cells to ROS, and enhancing the synergistic PDT effect. The G-quadruplex/hemin DNAzyme mimicks horseradish peroxidase (HRP) to catalyze the endogenous H2O2 to O2, overcoming hypoxia condition in tumors. The introduced UCNP converts NIR irradiation with deep tissue penetration to light with shorter wavelength, exciting PP to transform the abundant O2 to 1O2. The integration of gene editing and PDT allows substantial accumulation of 1O2 in cancer cells for enhanced cell apoptosis, and this synergistic PDT has shown remarkable therapeutic efficacy in a breast cancer mouse model.

A Versatile and Efficient Method to Isolate DNA-Polymer Conjugates

We present a facile and adaptable method to purify and isolate DNA-polymer conjugates from different uncharged homo, random, or block copolymer families. Anion exchange chromatography is used to separate the reaction solution and retrieve the excess unreacted polymer and oligonucleotide. The stationary phase has a high efficiency (25 nmol of DNA per run), facilitating the purification of large batches without compromising the peak shape and resolution. To demonstrate the versatility of this method, different types of polymers, including acrylates, methacrylates, and acrylamides containing hydrophilic and hydrophobic blocks, were purified with high yields. Additionally, DNA-polymer conjugates with various DNA block lengths were also successfully purified, further highlighting the broad applicability of this method.

Cascade dynamic assembly/disassembly of DNA nanoframework enabling the controlled delivery of CRISPR-Cas9 system

CRISPR-Cas9 has been explored as a therapeutic agent for down-regulating target genes; the controlled delivery of Cas9 ribonucleoprotein (RNP) is essential for therapeutic efficacy and remains a challenge. Here, we report cascade dynamic assembly/disassembly of DNA nanoframework (NF) that enables the controlled delivery of Cas9 RNP. NF was prepared with acrylamide-modified DNA that initiated cascade hybridization chain reaction (HCR). Through an HCR, single-guide RNA was incorporated to NF; simultaneously, the internal space of NF was expanded, facilitating the loading of Cas9 protein. NF was designed with hydrophilic acylamino and hydrophobic isopropyl, allowing dynamic swelling and aggregation. The responsive release of Cas9 RNP was realized by introducing disulfide bond-containing N,N-bis(acryloyl)cystamine that was specifically in response to glutathione of cancer cells, triggering the complete disassembly of NF. In vitro and in vivo investigations demonstrated the high gene editing efficiency in cancer cells, the hypotoxicity in normal cells, and notable antitumor efficacy in a breast cancer mouse model.

Tomography of DNA tiles influences the kinetics of surface-mediated DNA self-assembly

This manuscript studies the impact of extruding hairpins on two-dimensional self-assembly of DNA tiles on solid surface. Hairpins are commonly used as tomographic markers in DNA nanostructures for atomic force microscopy imaging. In this study, we have discovered that hairpins play a more active role. They modulate the adsorption of the DNA tiles onto the solid surface, thus changing the tile assembly kinetics on the solid surface. Based on this discovery, we were able to promote or slow down DNA self-assembly on the surface by changing the hairpin locations on the DNA tiles. This knowledge gained will be helpful for the future design of DNA self-assembly on surface.

Preparation, applications, and challenges of functional DNA nanomaterials

As a carrier of genetic information, DNA is a versatile module for fabricating nanostructures and nanodevices. Functional molecules could be integrated into DNA by precise base complementary pairing, greatly expanding the functions of DNA nanomaterials. These functions endow DNA nanomaterials with great potential in the application of biomedical field. In recent years, functional DNA nanomaterials have been rapidly investigated and perfected. There have been reviews that classified DNA nanomaterials from the perspective of functions, while this review primarily focuses on the preparation methods of functional DNA nanomaterials. This review comprehensively introduces the preparation methods of DNA nanomaterials with functions such as molecular recognition, nanozyme catalysis, drug delivery, and biomedical material templates. Then, the latest application progress of functional DNA nanomaterials is systematically reviewed. Finally, current challenges and future prospects for functional DNA nanomaterials are discussed.

Defined positive charge patterns created on DNA nanostructures determine cellular uptake efficiency

We provide an effective method to create DNA nanostructures below 100 nm with defined charge patterns and explore whether the density and location of charges affect the cellular uptake efficiency of nanoparticles (NPs). To avoid spontaneous charge neutralization, the negatively charged polymer nanopatterns were first created by in situ polymerization using photoresponsive monomers on DNA origami. Subsequent irradiation generated positive charges on the immobilized polymers, achieving precise positively charged patterns on the negatively charged DNA surface. Via this method, we have discovered that the positive charges located on the edges of nanostructures facilitate more efficient cellular uptake in comparison to the central counterparts. In addition, the high-density positive charge decoration could also enhance particle penetration into 3D multicellular spheroids. This strategy paves a new way to construct elaborate charge-separated substructures on NP surfaces and holds great promise for a deeper understanding of the influence between the surface charge distribution and nano-bio interactions.

A Proton-Activatable DNA-Based Nanosystem Enables Co-Delivery of CRISPR/Cas9 and DNAzyme for Combined Gene Therapy

CRISPR/Cas9 is emerging as a platform for gene therapeutics, and the treatment efficiency is expected to be enhanced by combination with other therapeutic agents. Herein, we report a proton-activatable DNA-based nanosystem that enables co-delivery of Cas9/sgRNA and DNAzyme for the combined gene therapy of cancer. Ultra-long ssDNA chains, which contained the recognition sequences of sgRNA in Cas9/sgRNA, DNAzyme sequence and HhaI enzyme cleavage site, were synthesized as the scaffold of the nanosystem. The DNAzyme cofactor Mn²⁺ was used to compress DNA chains to form nanoparticles and acid-degradable polymer-coated HhaI enzymes were assembled on the surface of nanoparticles. In response to protons in lysosome, the polymer coating was decomposed and HhaI enzyme was consequently exposed to recognize and cut off the cleavage sites, thus triggering the release of Cas9/sgRNA and DNAzyme to regulate gene expressions to achieve a high therapeutic efficacy of breast cancer.

Chemically Modified DNA Nanostructures for Drug Delivery

Based on predictable, complementary base pairing, DNA can be artificially pre-designed into versatile DNA nanostructures of well-defined shapes and sizes. With excellent addressability and biocompatibility, DNA nanostructures have been widely employed in biomedical research, such as bio-sensing, bio-imaging, and drug delivery. With the development of the chemical biology of nucleic acid, chemically modified nucleic acids are also gradually developed to construct multifunctional DNA nanostructures. In this review, we summarize the recent progress in the construction and functionalization of chemically modified DNA nanostructures. Their applications in the delivery of chemotherapeutic drugs and nucleic acid drugs are highlighted. Furthermore, the remaining challenges and future prospects in drug delivery by chemically modified DNA nanostructures are discussed.

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With excellent addressability and biocompatibility, DNA nanostructures are promising candidates for bio-sensing, bio-imaging, and drug delivery

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The recent progress in chemical modifications of DNA nanostructures is summarized

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Chemically modified DNA nanostructures for efficient delivery of chemotherapeutic drugs and nucleic acid drugs are highlighted

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Challenges and prospects of future development toward chemically modified DNA nanostructures for drug delivery are discussed

Engineered Aptamer-Organic Amphiphile Self-Assemblies for Biomedical Applications: Progress and Challenges

Currently, nucleic acid aptamers are exploited as robust targeting ligands in the biomedical field, due to their specific molecular recognition, little immunogenicity, low cost, ect. Thanks to the facile chemical modification and high hydrophilicity, aptamers can be site-specifically linked with hydrophobic moieties to prepare aptamer-organic amphiphiles (AOAs), which spontaneously assemble into aptamer-organic amphiphile self-assemblies (AOASs). These polyvalent self-assemblies feature with enhanced target-binding ability, increased resistance to nuclease, and efficient cargo-loading, making them powerful platforms for bioapplications, including targeted drug delivery, cell-based cancer therapy, biosensing, and bioimaging. Besides, the morphology of AOASs can be elaborately manipulated for smarter biomedical functions, by regulating the hydrophilicity/hydrophobicity ratio of AOAs. Benefiting from the boom in DNA synthesis technology and nanotechnology, various types of AOASs, including aptamer-polymer amphiphile self-assemblies, aptamer-lipid amphiphile self-assemblies, aptamer-cell self-assemblies, ect, have been constructed with great biomedical potential. Particularly, stimuli-responsive AOASs with transformable structure can realize site-specific drug release, enhanced tumor penetration, and specific target molecule detection. Herein, the general synthesis methods of oligonucleotide-organic amphiphiles are firstly summarized. Then recent progress in different types of AOASs for bioapplications and strategies for morphology control are systematically reviewed. The present challenges and future perspectives of this field are also discussed.

DNA Origami-Encoded Integration of Heterostructures

Integrating dissimilar materials at the nanoscale is crucial for modern electronics and optoelectronics. The structural DNA nanotechnology provides a universal platform for precision assembly of materials; nevertheless, heterogeneous integration of dissimilar materials with DNA nanostructures has yet to be explored. Here we report a DNA origami-encoded strategy for integrating silica-metal heterostructures. Theoretical and experimental studies reveal distinctive mechanisms for the binding and aggregation of silica and metal clusters on protruding double-stranded DNA (dsDNA) strands that are prescribed on the DNA origami template. In particular, the binding energy differences of silica/metal clusters and DNA molecules underlies the accessibilities of dissimilar material areas on DNA origami. We find that, by programming the densities and lengths of protruding dsDNA strands on DNA origami, silica and metal materials can be independently deposited at their predefined areas with a high vertical precision of 2 nm. We demonstrate the integration of silica-gold and silica-silver heterostructures with high site addressability. This DNA nanotechnology-based strategy is thus applicable for integrating various types of dissimilar materials, which opens new routes for bottom-up electronics.

Multi-Wavelength Photopolymerization of Stable Poly(Catecholamines)-DNA Origami Nanostructures

The synthesis of multicomponent polymer hybrids with nanometer precision is chemically challenging in the bottom‐up synthesis of complex nanostructures. Here, we leverage the fidelity of the DNA origami technique to install a multiple wavelength responsive photopolymerization system with nanometer resolution. By precisely immobilizing various photosensitizers on the origami template, which are only activated at their respective maximum wavelength, we can control sequential polymerization processes. In particular, the triggered photosensitizers generate reactive oxygen species that in turn initiate the polymerization of the catecholamines dopamine and norepinephrine. We imprint polymeric layers at designated positions on DNA origami, which modifies the polyanionic nature of the DNA objects, thus promoting their uptake into living cells while preserving their integrity. Our herein proposed method provides a rapid platform to access complex 3D nanostructures by customizing material and biological interfaces.

Functional DNA-Polymer Conjugates

DNA nanotechnology has seen large developments over the last 30 years through the combination of solid phase synthesis and the discovery of DNA nanostructures. Solid phase synthesis has facilitated the availability of short DNA sequences and the expansion of the DNA toolbox to increase the chemical functionalities afforded on DNA, which in turn enabled the conception and synthesis of sophisticated and complex 2D and 3D nanostructures. In parallel, polymer science has developed several polymerization approaches to build di- and triblock copolymers bearing hydrophilic, hydrophobic, and amphiphilic properties. By bringing together these two emerging technologies, complementary properties of both materials have been explored; for example, the synthesis of amphiphilic DNA-polymer conjugates has enabled the production of several nanostructures, such as spherical and rod-like micelles. Through both the DNA and polymer parts, stimuli-responsiveness can be instilled. Nanostructures have consequently been developed with responsive structural changes to physical properties, such as pH and temperature, as well as short DNA through competitive complementary binding. These responsive changes have enabled the application of DNA-polymer conjugates in biomedical applications including drug delivery. This review discusses the progress of DNA-polymer conjugates, exploring the synthetic routes and state-of-the-art applications afforded through the combination of nucleic acids and synthetic polymers.

Digital Numbers Constructed by Fine Patterned Polydopamine on DNA Templates

Using DNA nanostructures as templates to synthesize shape-controlled polydopamine (PDA) is a promising strategy to realize the fabrication of exquisite PDA nanomaterials. However, previous studies using small DNA tiles as templates could only afford very simple structures such as lines and crosses due to the limited space on the template and the relatively low resolution of the PDA nanopatterns. Therefore, the best resolution of the PDA nanostructures that can be achieved by this technique is carefully investigated. And by connecting several DNA tiles together, larger DNA templates are built up and achieve the synthesis of complicated digital nanopatterned PDA structures.

Programmable site-specific functionalization of DNA origami with polynucleotide brushes

Combining surface-initiated, TdT (terminal deoxynucleotidyl transferase) catalyzed enzymatic polymerization (SI-TcEP) with precisely engineered DNA origami nanostructures (DONs) presents an innovative pathway for the generation of stable, polynucleotide brush-functionalized origami nanostructures. We demonstrate that SI-TcEP can site-specifically pattern DONs with brushes containing both natural and non-natural nucleotides. The brush functionalization can be precisely controlled in terms of the location of initiation sites on the origami core and the brush height and composition. Coarse-grained simulations predict the conformation of the brush-functionalized DONs that agree well with the experimentally observed morphologies. We find that polynucleotide brush-functionalization increases the nuclease resistance of DONs significantly, and that this stability can be spatially programmed through the site-specific growth of polynucleotide brushes. The ability to site-specifically decorate DONs with brushes of natural and non-natural nucleotides provides access to a large range of functionalized DON architectures that would allow for further supramolecular assembly, and for potential applications in smart nanoscale delivery systems.

Assembly of Dynamic Supramolecular Polymers on a DNA Origami Platform

Biological processes rely on transient interactions that govern assembly of biomolecules into higher order, multi-component systems. A synthetic platform for the dynamic assembly of multicomponent complexes would provide novel entries to study and modulate the assembly of artificial systems into higher order topologies. Here, we establish a hybrid DNA origami-based approach as an assembly platform that enables dynamic templating of supramolecular architectures. It entails the site-selective recruitment of supramolecular polymers to the platform with preservation of the intrinsic dynamics and reversibility of the assembly process. The composition of the supramolecular assembly on the platform can be tuned dynamically, allowing for monomer rearrangement and inclusion of molecular cargo. This work should aid the study of supramolecular structures in their native environment in real-time and incites new strategies for controlled multicomponent self-assembly of synthetic building blocks.

DNA Origami Meets Polymers: A Powerful Tool for the Design of Defined Nanostructures

The combination of DNA origami nanostructures and polymers provides a new possibility to access defined structures in the 100 nm range. In general, DNA origami serves as a versatile template for the highly specific arrangement of polymer chains. Polymer-DNA hybrid nanostructures can either be created by growing the polymer from the DNA template or by attaching preformed polymers to the DNA scaffold. These conjugations can be of a covalent nature or be based on base-pair hybridization between respectively modified polymers and DNA origami. Furthermore, the negatively charged DNA backbone permits interaction with positively charged polyelectrolytes to form stable complexes. The combination of polymers with tuneable characteristics and DNA origami allows the creation of a new class of hybrid materials, which could offer exciting applications for controlled energy transfer, nanoscale organic circuits, or the templated synthesis of nanopatterned polymeric structures.

Spatiotemporally programmable cascade hybridization of hairpin DNA in polymeric nanoframework for precise siRNA delivery

DNA nanostructures have been demonstrated as promising carriers for gene delivery. In the carrier design, spatiotemporally programmable assembly of DNA under nanoconfinement is important but has proven highly challenging due to the complexity-scalability-error of DNA. Herein, a DNA nanotechnology-based strategy via the cascade hybridization chain reaction (HCR) of DNA hairpins in polymeric nanoframework has been developed to achieve spatiotemporally programmable assembly of DNA under nanoconfinement for precise siRNA delivery. The nanoframework is prepared via precipitation polymerization with Acrydite-DNA as cross-linker. The potential energy stored in the loops of DNA hairpins can overcome the steric effect in the nanoframework, which can help initiate cascade HCR of DNA hairpins and achieve efficient siRNA loading. The designer tethering sequence between DNA and RNA guarantees a triphosadenine triggered siRNA release specifically in cellular cytoplasm. Nanoframework provides stability and ease of functionalization, which helps address the complexity-scalability-error of DNA. It is exemplified that the phenylboronate installation on nanoframework enhanced cellular uptake and smoothed the lysosomal escape. Cellular results show that the siRNA loaded nanoframework down-regulated the levels of relevant mRNA and protein. In vivo experiments show significant therapeutic efficacy of using siPLK1 loaded nanoframework to suppress tumor growth.

Combination of DNA with polymers

The preparation and applications of DNA containing polymers are comprehensively reviewed, and they are in the form of DNA−polymer covalent conjugators, supramolecular assemblies and hydrogels for advanced materials with promising features.

Synthesis and applications of anisotropic nanoparticles with precisely defined dimensions

Shape and size play powerful roles in determining the properties of a material; controlling these aspects with precision is therefore an important, fundamental goal of the chemical sciences. In particular, the introduction of shape anisotropy at the nanoscale has emerged as a potent way to access new properties and functionality, enabling the exploration of complex nanomaterials across a range of applications. Recent advances in DNA and protein nanotechnology, inorganic crystallization techniques, and precision polymer self-assembly are now enabling unprecedented control over the synthesis of anisotropic nanoparticles with a variety of shapes, encompassing one-dimensional rods, dumbbells and wires, two-dimensional and three-dimensional platelets, rings, polyhedra, stars, and more. This has, in turn, enabled much progress to be made in our understanding of how anisotropy and particle dimensions can be tuned to produce materials with unique and optimized properties. In this Review, we bring these recent developments together to critically appraise the different methods for the bottom-up synthesis of anisotropic nanoparticles enabling exquisite control over morphology and dimensions. We highlight the unique properties of these materials in arenas as diverse as electron transport and biological processing, illustrating how they can be leveraged to produce devices and materials with otherwise inaccessible functionality. By making size and shape our focus, we aim to identify potential synergies between different disciplines and produce a road map for future research in this crucial area.

DNA-Polymer Nanostructures by RAFT Polymerization and Polymerization-Induced Self-Assembly

Nanostructures derived from amphiphilic DNA-polymer conjugates have emerged prominently due to their rich self-assembly behavior; however, their synthesis is traditionally challenging. Here, we report a novel platform technology towards DNA-polymer nanostructures of various shapes by leveraging polymerization-induced self-assembly (PISA) for polymerization from single-stranded DNA (ssDNA). A "grafting from" protocol for thermal RAFT polymerization from ssDNA under ambient conditions was developed and utilized for the synthesis of functional DNA-polymer conjugates and DNA-diblock conjugates derived from acrylates and acrylamides. Using this method, PISA was applied to manufacture isotropic and anisotropic DNA-polymer nanostructures by varying the chain length of the polymer block. The resulting nanostructures were further functionalized by hybridization with a dye-labelled complementary ssDNA, thus establishing PISA as a powerful route towards intrinsically functional DNA-polymer nanostructures.

Photocontrolled Dopamine Polymerization on DNA Origami with Nanometer Resolution

Temporal and spatial control over polydopamine formation on the nanoscale can be achieved by installing an irradiation-sensitive polymerization system on DNA origami. Precisely distributed G-quadruplex structures on the DNA template serve as anchors for embedding the photosensitizer protoporphyrin IX, which-upon irradiation with visible light-induces the multistep oxidation of dopamine to polydopamine, producing polymeric structures on designated areas within the origami framework. The photochemical polymerization process allows exclusive control over polydopamine layer formation through the simple on/off switching of the light source. The obtained polymer-DNA hybrid material shows significantly enhanced stability, paving the way for biomedical and chemical applications that are typically not possible owing to the sensitivity of DNA.

From Interaction to Function in DNA-Templated Supramolecular Self-Assemblies

DNA-templated self-assembly represents a rich and growing subset of supramolecular chemistry where functional self-assemblies are programmed in a versatile manner using nucleic acids as readily-available and readily-tunable templates. In this review, we summarize the different DNA recognition modes and the basic supramolecular interactions at play in this context. We discuss the recent results that report the DNA-templated self-assembly of small molecules into complex yet precise nanoarrays, going from 1D to 3D architectures. Finally, we show their emerging functions as photonic/electronic nanowires, sensors, gene delivery vectors, and supramolecular catalysts, and their growing applications in a wide range of area from materials to biological sciences.

DNA-Programmed Chemical Synthesis of Polymers and Inorganic Nanomaterials

DNA nanotechnology, based on sequence-specific DNA recognition, could allow programmed self-assembly of sophisticated nanostructures with molecular precision. Extension of this technique to the preparation of broader types of nanomaterials would significantly improve nanofabrication technique to lower nanometer scale and even achieve single molecule operation. Using such exquisite DNA nanostructures as templates, chemical synthesis of polymer and inorganic nanomaterials could also be programmed with unprecedented accuracy and flexibility. This review summarizes recent advances in the synthesis and assembly of polymer and inorganic nanomaterials using DNA nanostructures as templates, and discusses the current challenges and future outlook of DNA templated nanotechnology.

Preparation of Biomolecule-Polymer Conjugates by Grafting-From Using ATRP, RAFT, or ROMP

Biomolecule-polymer conjugates are constructs that take advantage of the functional or otherwise beneficial traits inherent to biomolecules and combine them with synthetic polymers possessing specially tailored properties. The rapid development of novel biomolecule-polymer conjugates based on proteins, peptides, or nucleic acids has ushered in a variety of unique materials, which exhibit functional attributes including thermo-responsiveness, exceptional stability, and specialized specificity. Key to the synthesis of new biomolecule-polymer hybrids is the use of controlled polymerization techniques coupled with either grafting-from, grafting-to, or grafting-through methodology, each of which exhibit distinct advantages and/or disadvantages. In this review, we present recent progress in the development of biomolecule-polymer conjugates with a focus on works that have detailed the use of grafting-from methods employing ATRP, RAFT, or ROMP.

Atom Transfer Radical Polymerization for Biorelated Hybrid Materials

Proteins, nucleic acids, lipid vesicles, and carbohydrates are the major classes of biomacromolecules that function to sustain life. Biology also uses post-translation modification to increase the diversity and functionality of these materials, which has inspired attaching various other types of polymers to biomacromolecules. These polymers can be naturally (carbohydrates and biomimetic polymers) or synthetically derived and have unique properties with tunable architectures. Polymers are either grafted-to or grown-from the biomacromolecule's surface, and characteristics including polymer molar mass, grafting density, and degree of branching can be controlled by changing reaction stoichiometries. The resultant conjugated products display a chimerism of properties such as polymer-induced enhancement in stability with maintained bioactivity, and while polymers are most often conjugated to proteins, they are starting to be attached to nucleic acids and lipid membranes (cells) as well. The fundamental studies with protein-polymer conjugates have improved our synthetic approaches, characterization techniques, and understanding of structure-function relationships that will lay the groundwork for creating new conjugated biomacromolecular products which could lead to breakthroughs in genetic and tissue engineering.

Opportunities and Challenges in DNA-Hybrid Nanomaterials

Nature has inspired the development of many life-like materials. Although still simplistic, key biological functionalities have been incorporated, enabling a wide variety of applications. DNA-based systems, in particular, show high promise due to their ability to merge specific Watson-Crick base pairing with unique properties that are also programmable, scalable, or dynamic. By combining the fields of DNA-based covalent polymers, DNA origami, and DNA-functionalized supramolecular polymers, new frontiers in next-generation DNA-based hybrid materials that can outperform current bioartificial systems will be realized. Many challenges must still be overcome before this emerging technology can be materialized.

From DNA Nanotechnology to Material Systems Engineering

In the past 35 years, DNA nanotechnology has grown to a highly innovative and vibrant field of research at the interface of chemistry, materials science, biotechnology, and nanotechnology. Herein, a short summary of the state of research in various subdisciplines of DNA nanotechnology, ranging from pure "structural DNA nanotechnology" over protein-DNA assemblies, nanoparticle-based DNA materials, and DNA polymers to DNA surface technology is given. The survey shows that these subdisciplines are growing ever closer together and suggests that this integration is essential in order to initiate the next phase of development. With the increasing implementation of machine-based approaches in microfluidics, robotics, and data-driven science, DNA-material systems will emerge that could be suitable for applications in sensor technology, photonics, as interfaces between technical systems and living organisms, or for biomimetic fabrication processes.

Preparation of Well-Defined Polymers and DNA-Polymer Bioconjugates via Small-Volume eATRP in the Presence of Air

An aqueous electrochemically mediated atom transfer radical polymerization (eATRP) was performed in a small volume solution (75 μL) deposited on a screen-printed electrode (SPE). The reaction was open to air, thanks to the use of glucose oxidase (GOx) as an oxygen scavenger. Well-defined poly(2-(methylsulfinyl)ethyl acrylate) (PMSEA), poly(oligo(ethylene oxide) methyl ether methacrylate) (POEOMA), and corresponding DNA-polymer biohybrids were synthesized by the small-volume eATRP at room temperature. The reactions were simplified and polymerization rates increased by the application of the enzyme deoxygenating system and the compact electrochemical setup. Importantly, the volume of polymerization mixture was lowered to microliters, which not only decreases the cost for each reaction, but can also be potentially implemented in combinatorial chemistry and electrode-array configurations for high-throughput systems.

Recent Advances in Amphiphilic Polymer-Oligonucleotide Nanomaterials via Living/Controlled Polymerization Technologies

Over the past decade, the field of polymer-oligonucleotide nanomaterials has flourished because of the development of synthetic techniques, particularly living polymerization technologies, which provide access to polymers with well-defined architectures, precise molecular weights, and terminal or side-chain functionalities. Various "living" polymerization methods have empowered chemists with the ability to prepare functional polymer-oligonucleotide conjugates yielding a library of architectures, including linear diblock, comb, star, hyperbranched star, and gel morphologies. Since oligonucleotides are hydrophilic and synthetic polymers can be tailored with hydrophobicity, these amphiphilic polymer-oligonucleotide conjugates are capable of self-assembling into nanostructures with different shapes, leading to many high-value-added biomedical applications, such as drug delivery systems, gene regulation, and 3D-bioprinting. This review aims to highlight the main living polymerization approaches to polymer-oligonucleotide conjugates, including ring-opening metathesis polymerization, atom transfer radical polymerization (ATRP), reversible addition-fragmentation transfer polymerization (RAFT), and ring-opening polymerization of cyclic esters and N-carboxyanhydride. The self-assembly properties and resulting applications of polymer-DNA hybrid materials are highlighted as well.

Chemistries for DNA Nanotechnology

The predictable nature of DNA interactions enables the programmable assembly of highly advanced 2D and 3D DNA structures of nanoscale dimensions. The access to ever larger and more complex structures has been achieved through decades of work on developing structural design principles. Concurrently, an increased focus has emerged on the applications of DNA nanostructures. In its nature, DNA is chemically inert and nanostructures based on unmodified DNA mostly lack function. However, functionality can be obtained through chemical modification of DNA nanostructures and the opportunities are endless. In this review, we discuss methodology for chemical functionalization of DNA nanostructures and provide examples of how this is being used to create functional nanodevices and make DNA nanostructures more applicable. We aim to encourage researchers to adopt chemical modifications as part of their work in DNA nanotechnology and inspire chemists to address current challenges and opportunities within the field.

Microfluidically mediated atom-transfer radical polymerization

Microfluidically mediated atom-transfer radical polymerization can be used to fabricate polymer brushes with a controlled gradient.

Surface-Guided Chemical Processes on Self-Assembled DNA Nanostructures

Solid-liquid interfaces have been of great significance in the activation of chemical reactions via restricting the conformation or orientation of the reactants. Self-assembled DNA nanostructures encoded with tremendous chemical and physical information provide an efficient platform to unravel and regulate mechanisms of surface chemical processes. In this review, we discuss the surface addressability, morphological features, and charged properties of DNA nanostructures as well as the recognition, catalytic, and dynamic properties of DNA molecules. We highlight the synergies between the surface properties of DNA nanostructures and the molecular features of DNA strands, which is a key to the synthesis of conductive polymer nanomaterials with well-defined shapes or electronic/optical properties. We also focus on the control over the substrate channeling pathways of enzyme networks or metal nucleation on DNA nanostructures toward the production of specifically emissive metal nanoclusters. In the end, we provide an outlook of future possible directions based on the rational design of DNA-based self-assembly, including dynamic energy transfer, stimuli-responsive synthesis, and programmable activation of the mechanophores on the surfaces of DNA nanostructures.

Advanced Materials by Atom Transfer Radical Polymerization

Atom transfer radical polymerization (ATRP) has been successfully employed for the preparation of various advanced materials with controlled architecture. New catalysts with strongly enhanced activity permit more environmentally benign ATRP procedures using ppm levels of catalyst. Precise control over polymer composition, topology, and incorporation of site specific functionality enables synthesis of well-defined gradient, block, comb copolymers, polymers with (hyper)branched structures including stars, densely grafted molecular brushes or networks, as well as inorganic-organic hybrid materials and bioconjugates. Examples of specific applications of functional materials include thermoplastic elastomers, nanostructured carbons, surfactants, dispersants, functionalized surfaces, and biorelated materials.

Polymer tube nanoreactors via DNA-origami templated synthesis

We describe the stepwise synthesis of precise polymeric objects programmed by a 3D DNA tube transformed from a common 2D DNA tile as a precise biotemplate for atom transfer radical polymerization. The catalytic interior space of the DNA tube was utilized for synthesizing a bio-inspired polymer, polydopamine.

Fabrication of Defined Polydopamine Nanostructures by DNA Origami-Templated Polymerization

A versatile, bottom-up approach allows the controlled fabrication of polydopamine (PD) nanostructures on DNA origami. PD is a biosynthetic polymer that has been investigated as an adhesive and promising surface coating material. However, the control of dopamine polymerization is challenged by the multistage-mediated reaction mechanism and diverse chemical structures in PD. DNA origami decorated with multiple horseradish peroxidase-mimicking DNAzyme motifs was used to control the shape and size of PD formation with nanometer resolution. These fabricated PD nanostructures can serve as "supramolecular glue" for controlling DNA origami conformations. Facile liberation of the PD nanostructures from the DNA origami templates has been achieved in acidic medium. This presented DNA origami-controlled polymerization of a highly crosslinked polymer provides a unique access towards anisotropic PD architectures with distinct shapes that were retained even in the absence of the DNA origami template.