Dual Acid‐Responsive Micelle‐Forming Anticancer Polymers as New Anticancer Therapeutics

Cinnamaldehyde, a major active compound of cinnamon, is known to induce apoptotic cell death in numerous human cancer cells. Here, dual acid‐responsive polymeric micelle‐forming cinnamaldehyde prodrugs, poly[(3‐phenylprop‐2‐ene‐1,1‐diyl)bis(oxy)bis(ethane‐2,1‐diyl)diacrylate]‐co‐4,4’(trimethylene dipiperidine)‐co‐poly(ethylene glycol), termed PCAE copolymers, are reported. PCAE is designed to incorporate cinnamaldehyde via acid‐cleavable acetal linkages in its pH‐sensitive hydrophobic backbone and self assemble to form stable micelles which can encapsulate camptothecin (CPT). PCAE self assembles to form micelles which release CPT and cinnamaldehyde in pH‐dependent manners. PCAE micelles induce apoptotic cell death through the generation of intracellular reactive oxygen species (ROS) and exert synergistic anticancer effects with a payload of CPT in vitro and in vivo model of SW620 human colon tumor‐bearing mice. It is anticipated that dual acid‐sensitive micelle‐forming PCAE with intrinsic anticancer activities has enormous potential as novel anticancer therapeutics.     

NIR‐Triggered Synergic Photo‐chemothermal Therapy Delivered by Reduced Graphene Oxide/Carbon/Mesoporous Silica Nanocookies

A novel photo‐responsive drug carrier that doubles as a photothermal agent with a nanocookie‐like structure is constructed by coating amorphous carbon on a mesoporous silica support self‐assembled on a sheet of reduced graphene oxide. With a large payload (0.88 mmolg^?1) of a hydrophobic anticancer drug, (S)‐(+)‐camptothecin (CPT), nanocookies simultaneously provide a burst‐like drug release and intense heat upon near‐infrared exposure. Being biocompatible yet with a high efficiency for cell uptake, nanocookies have successfully eradicated subcutaneous tumors in 14 days following a single 5 min NIR irradiation without distal damage. These results demonstrate that the nanocookie is an excellent new delivery platform for local, on‐demand, NIR‐responsive, combined chemotherapy/hyperthermia for tumor treatment and other biomedical applications.     

Protein Adsorption Modes Determine Reversible Cell Attachment on Poly(N‐isopropyl acrylamide) Brushes

Protein adsorption and reversible cell attachment are investigated as a function of the grafting density of poly(N‐isopropyl acrylamide) (PNIPAM) brushes. Prior studies demonstrated that the thermally driven collapse of grafted PNIPAM above the lower critical solution temperature of 32 °C is not required for protein adsorption. Here, the dependence of reversible, protein‐mediated cell adhesion on the polymer chain density, above and below the lower critical solution temperature, is reported. Above 32 °C, protein adsorption on PNIPAM brushes grafted from a non‐adsorbing, oligo(ethylene oxide)‐coated surface exhibits a maximum with respect to the grafting density. Few cells attach to either dilute or densely grafted PNIPAM chains, independent of whether the polymer brush collapses above 32 °C. However, both cells and proteins adsorb reversibly at intermediate chain densities. This supports a model in which the proteins, which support reversible cell attachment, adsorb by penetrating the brushes at intermediate grafting densities, under poor solvent conditions. In this scenario, reversible protein adsorption to PNIPAM brushes is determined by the thermal modulation of relative protein‐segment attraction and osmotic repulsion.     

Swelling Behavior of Multiresponsive Poly(methacrylic acid)‐block‐‐poly(N‐isopropylacrylamide) Brushes Synthesized Using Surface‐Initiated Photoiniferter‐Mediated Photopolymerization

Surface‐initiated photoiniferter‐mediated photopolymerization (SI‐PMP) in presence of tetraethylthiuram disulfide is used to directly synthesize surface‐grafted poly(methacrylic acid)‐block‐poly(N‐isopropylacrylamide) (PMAA‐b‐PNIPAM) layers. The response of these PMAA‐b‐PNIPAM bi‐level brushes to changes in pH, temperature and ionic strength is investigated by using in‐situ multi‐angle ellipsometry to measure changes in solvated layer thickness. As expected for a block copolymer architecture, PMAA blocks swell as pH is increased, with the maximum change in the thickness occurring near pH = 5, and PNIPAM blocks exhibit lower critical solution temperature (LCST) behavior, marked by a broad transition between swollen and collapsed states. The response of the bi‐level brushes to changes in added salt at constant pH is complex, as the swelling behaviors of both the weak polyelectrolyte, PMAA, and thermoresponsive PNIPAM are affected by changes in ionic strength. This work demonstrates not only the robustness of SI‐PMP for making novel, bi‐level stimuli‐responsive brushes, but also the complex links between synthesis, structure, and response of these materials.     

Engineering Inorganic Nanoemulsions/Nanoliposomes by Fluoride‐Silica Chemistry for Efficient Delivery/Co‐Delivery of Hydrophobic Agents

A novel drug‐formulation protocol is developed to solve the delivery problem of hydrophobic drug molecules by using inorganic mesoporous silica nanocapsules (IMNCs) as an alternative to traditional organic emulsions and liposomes while preserving the advantages of inorganic materials. The unique structures of IMNCs are engineered by a novel fluoride‐silica chemistry based on a structural difference‐based selective etching strategy. The prepared IMNCs combine the functions of organic nanoemulsions or nanoliposomes with the properties of inorganic materials. Various spherical nanostructures can be fabricated simply by varying the synthetic parameters. The drug loading amount of a typical highly hydrophobic anticancer drug‐camptothecin (CPT) in IMNCs reaches as high as 35.1 wt%. The intracellular release of CPT from carriers is demonstrated in situ. In addition, IMNCs can play the role of organic nanoliposome (multivesicular liposome) in co‐encapsulating and co‐delivering hydrophobic (CPT) and hydrophilic (doxorubicin, DOX) anticancer drugs simultaneously. The co‐delivery of multi‐drugs in the same carrier and the intracellular release of the drug combinations enables a drug delivery system with efficient enhanced chemotherapeutic effect for DOX‐resistant MCF‐7/ADR cancer cells. The special IMNCs‐based “inorganic nanoemulsion”, as a proof‐of‐concept, can also be employed successfully to encapsulate and deliver biocompatible hydrophobic perfluorohexane (PFH) molecules for high intensity focused ultrasound (HIFU) synergistic therapy ex vivo and in vivo. Based on this novel design strategy, a wide range of inorganic material systems with similar “inorganic nanoemulsion or nanoliposome” functions will be developed to satisfy varied clinical requirements.     

Charge‐Reversal Drug Conjugate for Targeted Cancer Cell Nuclear Drug Delivery

DNA‐toxin anticancer drugs target nuclear DNA or its associated enzymes to elicit their pharmaceutical effects, but cancer cells have not only membrane‐associated but also many intracellular drug‐resistance mechanisms that limit their nuclear localization. Thus, delivering such drugs directly to the nucleus would bypass the drug‐resistance barriers. The cationic polymer poly(L ‐lysine) (PLL) is capable of nuclear localization and may be used as a drug carrier for nuclear drug delivery, but its cationic charges make it toxic and cause problems in in‐vivo applications. Herein, PLL is used to demonstrate a pH‐triggered charge‐reversal carrier to solve this problem. PLL's primary amines are amidized as acid‐labile β‐carboxylic amides (PLL/amide). The negatively charged PLL/amide has a very low toxicity and low interaction with cells and, therefore, may be used in vivo. But once in cancer cells' acidic lysosomes, the acid‐labile amides hydrolyze into primary amines. The regenerated PLL escapes from the lysosomes and traverses into the nucleus. A cancer‐cell targeted nuclear‐localization polymer–drug conjugate has, thereby, been developed by introducing folic‐acid targeting groups and an anticancer drug camptothecin (CPT) to PLL/amide (FA‐PLL/amide‐CPT). The conjugate efficiently enters folate‐receptor overexpressing cancer cells and traverses to their nuclei. The CPT conjugated to the carrier by intracellular cleavable disulfide bonds shows much improved cytotoxicity.     

Toward Macroscale,Isotropic Carbons with Graphene‐Sheet‐Like Electrical and Mechanical Properties

Realization of macroscale three‐dimensional isotropic carbons that retain the exceptional electrical and mechanical properties of graphene sheets remains a challenge. Here, a method for fabricating graphene‐derived carbons (GDCs) with isotropic properties approaching those of individual graphene sheets is reported. This synthesis scheme relies on direct cross‐linking of graphene sheets via the functional groups in graphene oxide to maximize electronic transport and mechanical reinforcement between sheets and the partial restacking of the sheets to increase the material density to about 1 g cm^‐3. These GDCs exhibit properties 3–6 orders of magnitude higher than previously reported 3D graphene assemblies.     

Bioinspired Anisotropic Hydrogel Actuators with On–Off Switchable and Color‐Tunable Fluorescence Behaviors

An effective approach to develop a novel macroscopic anisotropic bilayer hydrogel actuator with on–off switchable fluorescent color‐changing function is reported. Through combining a collapsed thermoresponsive graphene oxide‐poly(N‐isopropylacrylamide) (GO‐PNIPAM) hydrogel layer with a pH‐responsive perylene bisimide‐functionalized hyperbranched polyethylenimine (PBI‐HPEI) hydrogel layer via macroscopic supramolecular assembly, a bilayer hydrogel is obtained that can be tailored and reswells to form a 3D hydrogel actuator. The actuator can undergo complex shape deformation caused by the PNIPAM outside layer, then the PBI‐HPEI hydrogel inside layer can be unfolded to trigger the on–off switch of the pH‐responsive fluorescence under the green light irradiation. This work will inspire the design and fabrication of novel biomimetic smart materials with synergistic functions.     

Multifunctional Graphene Oxide‐based Triple Stimuli‐Responsive Nanotheranostics

Construction of multifunctional stimuli‐responsive nanosystems intelligently responsive to inner physiological and/or external irradiations based on nanobiotechnology can enable the on‐demand drug release and improved diagnostic imaging to mitigate the side‐effects of anticancer drugs and enhance the diagnostic/therapeutic outcome simultaneously. Here, a triple‐functional stimuli‐responsive nanosystem based on the co‐integration of superparamagnetic Fe₃O₄ and paramagnetic MnO_x nanoparticles (NPs) onto exfoliated graphene oxide (GO) nanosheets by a novel and efficient double redox strategy (DRS) is reported. Aromatic anticancer drug molecules can interact with GO nanosheets through supramolecular π stacking to achieve high drug loading capacity and pH‐responsive drug releasing performance. The integrated MnO_x NPs can disintegrate in mild acidic and reduction environment to realize the highly efficient pH‐responsive and reduction‐triggered T₁‐weighted magnetic resonance imaging (MRI). Superparamagnetic Fe₃O₄ NPs can not only function as the T₂‐weighted contrast agents for MRI, but also response to the external magnetic field for magnetic hyperthermia against cancer. Importantly, the constructed biocompatible GO‐based nanoplatform can inhibit the metastasis of cancer cells by downregulating the expression of metastasis‐related proteins, and anticancer drug‐loaded carrier can significantly reverse the multidrug resistance (MDR) of cancer cells.     

Graphene‐Based Nanoporous Materials Assembled by Mediation of Polyoxometalate Nanoparticles

A kind of graphene‐based nanoporous material is prepared through assembling graphene sheets mediated through polyoxometalate nanoparticles. Owing to the strong interaction between graphene and polyoxometalate, 2D graphene sheets with honeycomb‐latticed carbon atoms could assemble into a porous structure, in which 3D polyoxometalate nanoparticles serve as the crosslinkers. Nitrogen and hydrogen sorption analysis reveal that the as‐prepared graphene‐based hybrid material possesses a specific surface area of 680 m² g^?1 and a hydrogen uptake volume of 0.8?1.3 wt%. Infrared spectrometry is used to probe the electron density changes of polyoxometalate particle in the redox‐cycle and to verify the interaction between graphene and polyoxometalate. The as‐prepared graphene‐based materials are further characterized by Raman spectroscopy, X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy.     

Photothermally Sensitive Poly(N‐isopropylacrylamide)/Graphene Oxide Nanocomposite Hydrogels as Remote Light‐Controlled Liquid Microvalves

A photothermally sensitive poly(N‐isopropylacrylamide)/graphene oxide (PNIPAM/GO) nanocomposite hydrogel can be synthesized by in situ γ‐irradiation‐assisted polymerization of an aqueous solution of N‐isopropylacrylamide monomer in the presence of graphene oxide (GO). The colors and phase‐transition temperatures of the PNIPAM/GO hydrogels change with different GO doping levels. Due to the high optical absorbance of the GO, the nanocomposite hydrogel shows excellent photothermal properties, where its phase transitions can be controlled remotely by near‐infrared (NIR) laser irradiation, and it is completely reversible via laser exposure or non‐exposure. With a higher GO loading, the NIR‐induced temperature of the nanocomposite hydrogel increases more quickly than with a lower doping level and the temperature can be tuned effectively by the irradiation time. The nanocomposite hydrogel with its excellent photothermal properties will have great applications in the biomedical field, especially as microfluidic devices; this has been demonstrated in our experiments by way of remote microvalves to control fluidic flow. Such an “easy” and “clean” synthetic procedure initiated by γ‐irradiation can be extended for the efficient synthesis of other nanocomposite materials.     

A Multiresponsive Anisotropic Hydrogel with Macroscopic 3D Complex Deformations

As one of the most promising smart materials, stimuli‐responsive polymer hydrogels (SPHs) can reversibly change volume or shape in response to external stimuli. They thus have shown promising applications in many fields. While considerable progress of 2D deformation of SPHs has been achieved, the realization of 3D or even more complex deformation still remains a significant challenge. Here, a general strategy towards designing multiresponsive, macroscopically anisotropic SPHs (MA‐SPHs) with the ability of 3D complex deformations is reported. Through a local UV‐reduction of graphene oxide sheets (GOs) with a patterned fashion in the GO‐poly(N‐isopropylacrylamide) (GO‐PNIPAM) composite hydrogel sheet, MA‐SPHs can be achieved after the introduction of a second poly(methylacrylic acid) network in the unreduced part of GO‐PNIPAM hydrogel sheet. The resulting 3D MA‐SPHs can provide remote‐controllable light‐driven, as well as thermo‐, pH‐, and ionic strength‐triggered multiresponsive 3D complex deformations. Approaches in this study may provide new insights in designing and fabricating intelligent soft materials for bioinspired applications.     

Multifunctional Core/Shell Nanoparticles Self‐Assembled from pH‐Induced Thermosensitive Polymers for Targeted Intracellular Anticancer Drug Delivery

Core/shell nanoparticles that display a pH‐sensitive thermal response, self‐assembled from the amphiphilic tercopolymer, poly(N‐isopropylacrylamide‐co‐N,N‐dimethylacrylamide‐co‐10‐undecenoic acid) (P(NIPAAm‐co‐DMAAm‐co‐UA)), have recently been reported. In this study, folic acid is conjugated to the hydrophilic segment of the polymer through the free amine group (for targeting cancer cells that overexpress folate receptors) and cholesterol is grafted to the hydrophobic segment of the polymer. This polymer also self‐assembles into core/shell nanoparticles that exhibit pH‐induced temperature sensitivity, but they possess a more stable hydrophobic core than the original polymer P(NIPAAm‐co‐DMAAm‐co‐UA) and a shell containing folate molecules. An anticancer drug, doxorubicin (DOX), is encapsulated into the nanoparticles. DOX release is also pH‐dependent. DOX molecules delivered by P(NIPAAm‐co‐DMAAm‐co‐UA) and folate‐conjugated P(NIPAAm‐co‐DMAAm‐co‐UA)‐g‐cholesterol nanoparticles enter the nucleus more rapidly than those transported by P(NIPAAm‐co‐DMAAm)‐b‐poly(lactide‐co‐glycolide) nanoparticles, which are not pH sensitive. More importantly, these nanoparticles can recognize folate‐receptor‐expressing cancer cells. Compared to the nanoparticles without folate, the DOX‐loaded nanoparticles with folate yield a greater cellular uptake because of the folate‐receptor‐mediated endocytosis process, and, thus, higher cytotoxicity results. These multifunctional polymer core/shell nanoparticles may make a promising carrier to target drugs to cancer cells and release the drug molecules to the cytoplasm inside the cells.     

Efficient Synthesis of Heteroatom (N or S)‐Doped Graphene Based on Ultrathin Graphene Oxide‐Porous Silica Sheets for Oxygen Reduction Reactions

Heteroatom (N or S)‐doped graphene with high surface area is successfully synthesized via thermal reaction between graphene oxide and guest gases (NH₃ or H₂S) on the basis of ultrathin graphene oxide‐porous silica sheets at high temperatures. It is found that both N and S‐doping can occur at annealing temperatures from 500 to 1000 °C to form the different binding configurations at the edges or on the planes of the graphene, such as pyridinic‐N, pyrrolic‐N, and graphitic‐N for N‐doped graphene, thiophene‐like S, and oxidized S for S‐doped graphene. Moreover, the resulting N and S‐doped graphene sheets exhibit good electrocatalytic activity, long durability, and high selectivity when they are employed as metal‐free catalysts for oxygen reduction reactions. This approach may provide an efficient platform for the synthesis of a series of heteroatom‐doped graphenes for different applications.     

Multifunctional Three‐Dimensional T‐Junction Graphene Micro‐Wells: Energy‐Efficient,Plasma‐Enabled Growth and Instant Water‐Based Transfer for Flexible Device Applications

The “third‐generation” 3D graphene structures, T‐junction graphene micro‐wells (T‐GMWs) are produced on cheap polycrystalline Cu foils in a single‐step, low‐temperature (270 °C), energy‐efficient, and environment‐friendly dry plasma‐enabled process. T‐GMWs comprise vertical graphene (VG) petal‐like sheets that seemlessly integrate with each other and the underlying horizontal graphene sheets by forming T‐junctions. The microwells have the pico‐to‐femto‐liter storage capacity and precipitate compartmentalized PBS crystals. The T‐GMW films are transferred from the Cu substrates, without damage to the both, in de‐ionized or tap water, at room temperature, and without commonly used sacrificial materials or hazardous chemicals. The Cu substrates are then re‐used to produce similar‐quality T‐GMWs after a simple plasma conditioning. The isolated T‐GMW films are transferred to diverse substrates and devices and show remarkable recovery of their electrical, optical, and hazardous NO₂ gas sensing properties upon repeated bending (down to 1 mm radius) and release of flexible trasparent display plastic substrates. The plasma‐enabled mechanism of T‐GMW isolation in water is proposed and supported by the Cu plasma surface modification analysis. Our GMWs are suitable for various optoelectronic, sesning, energy, and biomedical applications while the growth approach is potentially scalable for future pilot‐scale industrial production.     

High‐Sensitivity,Skin‐Attachable,and Stretchable Array of Thermo‐Responsive Suspended Gate Field‐Effect Transistors with Thermochromic Display

The fabrication of a skin‐attachable, stretchable array of high‐sensitivity temperature sensors is demonstrated. The temperature sensor consists of a single‐walled carbon nanotube field‐effect transistor with a suspended gate electrode of poly(N‐isopropylacrylamide) (PNIPAM)‐coated gold grid/poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate and thermochromic leuco dye. The sensor exhibits a very high sensitivity of 6.5% °C^?1 at temperatures between 25 and 45 °C. With increasing temperature, the suspended gate electrode bends due to the deswelling of the PNIPAM, resulting in the reduction of the air gap to increase the drain current under a constant gate voltage. At the same time, the leuco dye coated on top of the transparent gate electrode changes color to visualize changes in temperature. The 4 × 6 integrated temperature sensor array integrated using liquid metal interconnections exhibits mechanical and electrical stability under 50% biaxial stretching and allows for the spatial mapping of temperature with visual color display regardless of wrist movement while attached to the skin of the wrist. This work is expected to be widely useful in the development of skin‐attachable electronics for medical and health‐care monitoring.     

Triphenylphosphonium‐Conjugated Poly(ε‐caprolactone)‐Based Self‐Assembled Nanostructures as Nanosized Drugs and Drug Delivery Carriers for Mitochondria‐Targeting Synergistic Anticancer Drug Delivery

For mitochondria‐targeting delivery, a coupling reaction between poly(ε‐caprolactone) diol (PCL diol) and 4‐carboxybutyltriphenylphosphonium (4‐carboxybutyl TPP) results in the synthesis of amphiphilic TPP‐PCL‐TPP (TPCL) polymers with a bola‐like structure. In aqueous environments, the TPCL polymer self‐assembled via cosolvent dispersion and film hydration, resulting in the formation of cationic nanoparticles (NPs) less than 50 nm in size with zeta‐potentials of approximately 40 mV. Interestingly, different preparation methods for TPCL NPs result in various morphologies such as nanovesicles, nanofibers, and nanosheets. In vitro cytotoxicity results with TPCL NPs indicate IC₅₀ values of approximately 10–60 μg mL^?1, suggesting their potential as anticancer nanodrugs. TPCL NPs can be loaded both with hydrophobic doxorubicin (Dox) and its hydrophilic salt form (Dox·HCl), and their drug loading contents are approximately 2–10 wt% depending on the loading method and the hydrophilicity/hydrophobicity of the drugs. Although Dox·HCl exhibits more cellular and nuclear uptake, resulting in greater antitumor effects than Dox, most drug‐loaded TPCL NPs exhibit higher mitochondrial uptake and approximately 2–7‐fold higher mitochondria‐to‐nucleus preference than free drugs, resulting in superior (approximately 7.5–18‐fold) tumor‐killing activity for most drug‐loaded TPCL NPs compared with free drugs. In conclusion, TPCL‐based nanoparticles have potential both as antitumor nanodrugs themselves and as nanocarriers for chemical therapeutics.     

A Controllable Self‐Assembly Method for Large‐Scale Synthesis of Graphene Sponges and Free‐Standing Graphene Films

A simple method to prepare large‐scale graphene sponges and free‐standing graphene films using a speed vacuum concentrator is presented. During the centrifugal evaporation process, the graphene oxide (GO) sheets in the aqueous suspension are assembled to generate network‐linked GO sponges or a series of multilayer GO films, depending on the temperature of a centrifugal vacuum chamber. While sponge‐like bulk GO materials (GO sponges) are produced at 40 °C, uniform free‐standing GO films of size up to 9 cm² are generated at 80 °C. The thickness of GO films can be controlled from 200 nm to 1 µm based on the concentration of the GO colloidal suspension and evaporation temperature. The synthesized GO films exhibit excellent transparency, typical fluorescent emission signal, and high flexibility with a smooth surface and condensed density. Reduced GO sponges and films with less than 5 wt% oxygen are produced through a thermal annealing process at 800 °C with H₂/Ar flow. The structural flexibility of the reduced GO sponges, which have a highly porous, interconnected, 3D network, as well as excellent electrochemical properties of the reduced GO film with respect to electrode kinetics for the [Fe(CN)₆]^3?/4? redox system, are demonstrated.     

Nitrogen‐Doped Nanoporous Carbon/Graphene Nano‐Sandwiches: Synthesis and Application for Efficient Oxygen Reduction

A zeolitic‐imidazolate‐framework (ZIF) nanocrystal layer‐protected carbonization route is developed to prepare N‐doped nanoporous carbon/graphene nano‐sandwiches. The ZIF/graphene oxide/ZIF sandwich‐like structure with ultrasmall ZIF nanocrystals (i.e., ≈20 nm) fully covering the graphene oxide (GO) is prepared via a homogenous nucleation followed by a uniform deposition and confined growth process. The uniform coating of ZIF nanocrystals on the GO layer can effectively inhibit the agglomeration of GO during high‐temperature treatment (800 °C). After carbonization and acid etching, N‐doped nanoporous carbon/graphene nanosheets are formed, with a high specific surface area (1170 m² g^?1). These N‐doped nanoporous carbon/graphene nanosheets are used as the nonprecious metal electrocatalysts for oxygen reduction and exhibit a high onset potential (0.92 V vs reversible hydrogen electrode; RHE) and a large limiting current density (5.2 mA cm^?2 at 0.60 V). To further increase the oxygen reduction performance, nanoporous Co‐N_x/carbon nanosheets are also prepared by using cobalt nitrate and zinc nitrate as cometal sources, which reveal higher onset potential (0.96 V) than both commercial Pt/C (0.94 V) and N‐doped nanoporous carbon/graphene nanosheets. Such nanoporous Co‐N_x/carbon nanosheets also exhibit good performance such as high activity, stability, and methanol tolerance in acidic media.     

A Hollow‐Core,Magnetic, and Mesoporous Double‐Shell Nanostructure: In Situ Decomposition/Reduction Synthesis,Bioimaging, and Drug‐Delivery Properties

A novel in situ decomposition/reduction approach is developed to manu­facture hollow core, magnetic, and mesoporous double‐shell nanostructures (HMMNSs) via in situ decomposition and reduction of a β‐FeOOH nanorod core and organosilicate‐incorporated silica‐shell precursor. The formed HMMNSs are then aminated by silanization for further covalent conjugation to rhodamine B isothiocyanate (RBITC) and poly(ethylene glycol) (PEG) chains. The resultant RBITC‐grafted and PEGylated nanocomposites (HMMNS–R/Ps) have excellent blood compatibility and very low cytotoxicity towards HeLa and MCF‐7 cells, and can be taken up by cancer cells effectively in a dose‐dependent manner, as confirmed by in vitro flow cytometry, confocal luminescence imaging, and magnetic resonance imaging (MRI) studies. In vivo MRI studies coupled with Prussian blue staining of slides from different organs show that the nanocomposites preferentially accumulate in liver and spleen after intravenous injection, which suggests a potential application of the nanocomposites as MRI contrast agents. Importantly, the HMMNS–R/P nanocomposites show high loading capacity for water‐insoluble anticancer drugs (docetaxel or camptothecin) owing to the presence of a large inner cavity and enhanced surface area and pore volume. Furthermore, the drug‐loaded nanocomposites exhibit greater cytotoxicity than the corresponding free drugs. These results confirm that the HMMNS–R/P nanocomposites are promising candidates for simultaneous bioimaging and drug delivery.