Black Phosphorus Quantum Dots Encapsulated Biodegradable Hollow Mesoporous MnO2: Dual-Modality Cancer Imaging and Synergistic Chemo-Phototherapy

To achieve an accurate diagnosis and efficient tumor treatment, developing a facile and powerful strategy to build multifunctional nanotheranostics is highly desirable. Benefiting from the distinct characteristics of black phosphorus quantum dots (BPQDs), herein, a versatile nanoprobe (H-MnO₂/DOX/BPQDs) is constructed for dual-modality cancer imaging and synergistic chemo-phototherapy. The hollow mesoporous MnO₂ (H-MnO₂) nanoparticles are sequentially decorated with a cationic polymer poly (allylamine hydrochloride) (PAH) and an anionic polymer poly (acrylic acid) (PAA). The obtained H-MnO₂-PAH-PAA is covalently grafted with BPQDs-PEG-NH₂ via a carbodiimide cross-linking reaction and then loaded with anti-cancer drug DOX to form final nanoprobe H-MnO₂/DOX/BPQDs. Under the tumor microenvironment, H-MnO₂/DOX/BPQDs is degraded to release encapsulated functional molecules DOX and BPQDs. DOX acts as the chemotherapy and fluorescence imaging agent, and BPQDs endows the nanoprobe with photodynamic therapy (PDT) and photothermal therapy (PTT) abilities under dual laser irradiation of 630 and 808 nm. H-MnO₂ offers contrasts for magnetic resonance imaging (MRI) and facilitates conversion of endogenous H₂O₂ to oxygen, thereby relieving tumor hypoxia and enhancing PDT efficacy. All in vitro and in vivo results demonstrate that the designed nanoprobe displays dual-modality MRI/FL imaging and synergistic chemotherapy/PDT/PTT, which ultimately enhances the accuracy of cancer diagnosis and therapeutic performance.     

Selenium‐Containing Polymer@Metal‐Organic Frameworks Nanocomposites as an Efficient Multiresponsive Drug Delivery System

The development of efficient multiresponsive drug delivery systems (DDSs) to control drug release has been widely explored. Herein, a facile strategy is reported that enables the micelles of the selenium‐containing polymer with the drug to be encapsulated in metal‐organic frameworks (MOFs), which serves as multiresponsive drug release by employing the selenium‐containing polymers with redox‐triggered property and the MOFs with pH‐triggered property in DDS. In this case, the micelles of selenium‐containing polymers, as core easily disassembles in the presence of redox agents, can then release the drug in MOFs matrixes. The ZIF‐8 (one type of MOFs) crystal frameworks serving as shell can collapse only under low pH conditions, and the drug can be further released. In the presence of external redox agents as well as the pH stimuli, the prepared nanocomposite (P@ZIF‐8) drug system exhibits the capability of multiresponsive release of the doxorubicin (DOX) and possesses good selectivity in releasing the DOX under low pH conditions instead of normal pH conditions. In addition, the merits of P@ZIF‐8 such as good biocompatibility, multiresponsive release properties, and especially the selective release properties under different pH conditions make the materials highly promising candidates for the realization of controlled drug delivery in tumor tissue systems.     

A Smart Hyperthermia Nanofiber with Switchable Drug Release for Inducing Cancer Apoptosis

A smart hyperthermia nanofiber is described with simultaneous heat generation and drug release in response to ‘on‐off’ switching of alternating magnetic field (AMF) for induction of skin cancer apoptosis. The nanofiber is composed of a chemically‐crosslinkable temperature‐responsive polymer with an anticancer drug (doxorubicin; DOX) and magnetic nanoparticles (MNPs), which serve as a trigger of drug release and a source of heat, respectively. By chemical crosslinking, the nanofiber mesh shows switchable changes in the swelling ratio in response to alternating ‘on‐off’ switches of AMF because the self‐generated heat from the incorporated MNPs induces the deswelling of polymer networks in the nanofiber. Correspondingly, the ‘on‐off’ release of DOX from the nanofibers is observed in response to AMF. The 70% of human melanoma cells died in only 5 min application of AMF in the presence of the MNPs and DOX incorporated nanofibers by double effects of heat and drug. Taken together these advantages on both the nano‐ and macroscopic scale of nanofibers demonstrate that the dynamically and reversibly tunable structures have the potential to be utilized as a manipulative hyperthermia material as well as a switchable drug release platform by simple switching an AMF ‘on’ and ‘off’.     

Dual Stimuli‐Responsive Supramolecular Polypeptide‐Based Hydrogel and Reverse Micellar Hydrogel Mediated by Host–Guest Chemistry

Versatile strategies are currently being discovered for the fabrication of synthetic polypeptide‐based hybrid hydrogels, which have potential applications in polymer therapeutics and regenerative medicine. Herein, a new concept—the reverse micellar hydrogel—is introduced, and a versatile strategy is provided for fabricating supramolecular polypeptide‐based normal micellar hydrogel and reverse micellar hydrogels from the same polypeptide‐based copolymer via the cooperation of host–guest chemistry and hydrogen‐bonding interactions. The supramolecular hydrogels are thoroughly characterized, and a mechanism for their self‐assembly is proposed. These hydrogels can respond to dual stimuli—temperature and pH—and their mechanical and controlled drug‐release properties can be tuned by the copolymer topology and the polypeptide composition. The reverse micellar hydrogel can load 10% of the anticancer drug doxorubicin hydrochloride (DOX) and sustain DOX release for 45 days, indicating that it could be useful as an injectable drug delivery system.     

Ultralong Circulating Lollipop‐Like Nanoparticles Assembled with Gossypol,Doxorubicin, and Polydopamine via π–π Stacking for Synergistic Tumor Therapy

Long blood circulation in vivo remains a challenge to dual‐drug‐loaded nanocarriers for synergistic chemotherapy. Herein, a novel strategy to prepare lollipop‐like dual‐drug‐loaded nanoparticles (DOX–PDA–gossypol NPs) is developed based on the self‐assembly of gossypol, doxorubicin (DOX), and polydopamine (PDA) via π–π stacking. Dopamine polymerizes to PDA and fills the gaps between the gossypol and DOX molecules to form the super compact long‐circulating nanoparticles. The DOX–PDA–gossypol NPs show a suitable particle size of 59.6 ± 9.6 nm, high drug loading of 91%, superb stability, high maximum‐tolerated dose (MTD) of over 60 mg kg^‐1, and negligible toxicity. These NPs also exhibit pH‐dependent drug release and low combination index (0.23). Notably, they show dramatically ultralong blood circulation (>192 h) with elimination half times 458‐fold and 258‐fold longer than that of free DOX and free gossypol, respectively. These values are markedly higher than most of the reported results. Therefore, the DOX–PDA–gossypol NPs have a high tumor accumulation of 12% remaining on the 8th day postinjection. This characteristic contributes to the excellent tumor comprehensive synergistic therapeutic efficacy (TIR > 90%) with low administration dosage and is benefitted for widening the drug therapeutic window. Thus, the proposed strategy has remarkable potential for tumor synergistic therapy.     

Modulation of ambipolar charge transport characteristics in side-chain polystyrenes as host materials for solution processed OLEDs

A series of side-chain polystyrenes was developed as ambipolar hosts for solution processed organic light emitting diodes (OLEDs). The series was derived from the hole-only transport host molecule 1,3-Bis(N-carbazolyl)benzene (mCP). Electron transport ability was incorporated into the host polymers by the introduction of electron-poor heterocycles (pyridine or triazine) and extending delocalization of the lowest unoccupied molecular orbital (LUMO). The materials were tested in Ir-based green OLED devices with all organic layers processed from solution. Devices with the polymer combining triazine and carbazole on its side-chain exhibited a low luminance on-set voltage of 3.0 V and a current efficacy of 28.9 cd/A, which was more than 10 times higher than for devices with the mCP-based polymer (1.6 cd/A). The increase in performance is most likely due to an improvement of charge balance in the emissive layer, showing that our ambipolar polymers are good candidates for further wet-process optoelectronic applications.     

Ultrafast Electrochemical Trigger Drug Delivery Mechanism for Nanographene Micromachines

Nano/micromachines with autonomous motion are the frontier of nanotechnology and nanomaterial research. These self‐propelled nano/micromachines convert chemical energy obtained from their surroundings to propulsion. They have shown great potential in diagnostic and therapeutic applications. This work introduces a high‐speed tubular electrically conductive micromachine based on reduced nanographene oxide (n‐rGO) as a platform for drug delivery and platinum (Pt) as the catalytic inner layer. n‐rGO/Pt micromachines are loaded with doxorubicin (DOX) by a simple physical adsorption with a very high loading efficiency, displaying single‐ or multistrand wrapping of DOX monomers on the micromachine cylinders. More importantly, it is found that electron injection into DOX@n‐rGO/Pt micromachines via electrochemistry leads to expulsion of DOX from micromachines in motion within only a few seconds. An in vitro study confirms this efficient release mechanism in the presence of cancerous cells. The unique properties of the n‐rGO/Pt micromotor enable the effective management of DOX release at the tumor site and thus enhances the therapeutic efficiency and reduces the side toxicity toward the healthy tissue. These micromachine drug carriers combine the high loading capacity of conventional carbon‐based drug carriers with a fast and efficient electrochemical drug‐release mechanism.     

Liquid Metal-Enabled Microspheres with High Drug Loading and Multimodal Imaging for Artery Embolization

The drug-eluting microspheres that have been widely used in clinical treatments such as chemoembolization commonly suffer from inadequate drug loading and tracking difficulties. With inherent high density and excellent biocompatibility, liquid metal (LM) has been explored at the frontiers of medical imaging and clinical therapy. Herein, multifunctional microspheres (SA/LM/DOX) are reported with high drug loading and multimodal imaging by adsorbing silanized LM particles on sulfonated agarose microspheres (SA), which are capable of heating and accelerating drug release under an 808 nm near-infrared (NIR) laser. The negative SA microspheres can adsorb more positive drugs such as doxorubicin (DOX) up to 104 mg DOX per mL microspheres. It deserves to be mentioned that SA/LM/DOX microspheres have the function of multimodal imaging under computed tomography (CT), magnetic resonance imaging (MRI), and B-scan ultrasonography (US), which significantly facilitate location tracking during the embolization process. In rabbit ear central artery embolization, these microspheres are smoothly injected into the intended location of the vessel and successfully blocked blood flow, and eventually led to necrosis of rabbit ear. Overall, these microspheres with high drug loading capacity and multimodal contrast properties are promising candidates to be developed as new products for future clinical medicine.     

Codelivery of a π–π Stacked Dual Anticancer Drug Combination with Nanocarriers for Overcoming Multidrug Resistance and Tumor Metastasis

The multidrug resistance (MDR) of cancer cells is a major obstacle in cancer chemotherapy and very few strategies are available to overcome it. Here, a new strategy is developed to codeliver a π–π stacked dual anticancer drug combination with an actively targeted, pH‐ and reduction‐sensitive polymer micellar platform for combating multidrug resistance and tumor metastasis. In contrast to other methods, two traditional chemotherapeutics, doxorubicin (DOX) and 10‐hydroxycamptothecin with complex aromatic π–π conjugated structures, are integrated into one drug delivery system via a π–π stacking interaction, which enables the released drugs to evade the recognition of drug pumps due to a slight change in the drug's molecular structure. The micelles exhibit active targeting of DOX‐resistant human breast cancer MCF‐7 cells (MCF‐7/ADR) and have the ability to control the release of the drug in response to the microenvironmental stimuli of tumor cells. As a result, the codelivery of the π–π stacked dual anticancer drug combination displays high therapeutic efficacy in the MCF‐7/ADR tumor model and successfully prevents the lung metastasis of tumor cells. The mechanism underlying the reversal of MDR is investigated, and the results reveal that the synergistic effect of the π–π stacked dual drugs promotes mitochondria‐dependent apoptosis.     

Biodegradable Nanoparticles of Polyacrylic Acid–Stabilized Amorphous CaCO3 for Tunable pH‐Responsive Drug Delivery and Enhanced Tumor Inhibition

Inorganic nanoparticles (NPs) are promising drug delivery carriers owing to their high drug loading efficiency, scalable preparation, facile functionalization, and chemical/thermal stability. However, the clinical translation of inorganic nanocarriers is often hindered by their poor biodegradability and lack of controlled pH response. Herein, a fully degradable and pH‐responsive DOX@ACC/PAA NP (pH 7.4–5.6) is developed by encapsulating doxorubicin (DOX) in poly(acrylic acid) (PAA) stabilized amorphous calcium carbonate (ACC) NPs. The DOX‐loaded NPs have small sizes (62 ± 10 nm), good serum stability, high drug encapsulation efficiency (>80%), and loading capacity (>9%). By doping proper amounts of Sr²⁺ or Mg²⁺, the drug release of NPs can be further modulated to higher pH responsive ranges (pH 7.7–6.0), which enables drug delivery to the specific cell domains of tissues with a less acidic microenvironment. Tumor inhibition and lower drug acute toxicity are further confirmed via intracellular uptake tests and zebrafish models, and the particles also improve pharmacokinetics and drug accumulation in mouse xenograft tumors, leading to enhanced suppression of tumor growth. Owing to the excellent biocompatibility, biodegradability, and tunable drug release behavior, the present hybrid nanocarrier may find broad applications in tumor therapy.     

Effect of Chlorine or Ester Incorporation on Diketopyrrolopyrrole -Based Polymeric Semiconductors

Organic photovoltaic materials incorporating either chlorine atoms or ester groups have been studied as replacement strategy for fluorinated compounds. However, the characteristics of such materials when used in organic field-effect transistors (OFETs) remain unclear. The present work synthesized three polymers via the copolymerization of diketopyrrolopyrrole (DPP) with monothiophene units having no substituents or incorporating either chlorine atoms or ester groups. All three materials were found to have similar photophysical and electrochemical properties even though their repeating units had different substituents. The maximum hole mobility values for the polymer specimens were determined to be 0.37 cm² V⁻¹ s⁻¹. The introduction of chlorine into the DPP-based polymer generated an amorphous semiconductor material that makes it a very promising candidate for commercial OFETs since its properties are independent of fabrication conditions. The new polymeric semiconductors demonstrated herein suggest the viability of such materials with regard to incorporation in organic field-effect transistors.     

Hydration-Induced Void-Containing Hydrogels for Encapsulation and Sustained Release of Small Hydrophilic Molecules

Efficient encapsulation and sustained release of small hydrophilic molecules from traditional hydrogel systems are challenging due to the large mesh size of 3D networks and high water content. Furthermore, the encapsulated molecules are prone to early release from the hydrogel prior to use, resulting in a short shelf life of the formulation. Here, a hydration-induced void-containing hydrogel (HVH) based on hyperbranched polyglycerol-poly(propylene oxide)-hyperbranched polyglycerol (HPG-PPG-HPG) as a robust and efficient delivery system is presented for small hydrophilic molecules. Specifically, after the HPG-PPG-HPG is incubated overnight at 4 °C in the drug solution, it is hydrated into a hydrogel containing micron-sized voids, which can encapsulate hydrophilic drugs and achieve 100% drug encapsulation efficiency. In addition, the voids are surrounded by a densely packed polymer matrix, which restricts drug transport to achieve sustained drug release. The hydrogel/drug formulation can be stored for several months without changing the drug encapsulation and release properties. HVH hydrogels are injectable due to shear thinning properties. In rats, a single injection of the HPG-PPG-HPG hydrogel containing 8 µg of tetrodotoxin (TTX) produces sciatic nerve block lasting up to 10 h without any TTX-related systemic toxicity nor local toxicity to nerves and muscles.     

Redox‐Responsive and Drug‐Embedded Silica Nanoparticles with Unique Self‐Destruction Features for Efficient Gene/Drug Codelivery

The development of advanced gene/drug codelivery carriers with stimuli‐responsive release manner for complementary cancer therapy is desirable. In this study, novel disulfide‐bridged and doxorubicin (DOX)‐embedded degradable silica nanoparticles (DS‐DOX) with unique self‐destruction features are synthesized by a facile one‐pot method. In order to realize codelivery of genes and drugs, the surface of DS‐DOX nanoparticles is readily functionalized with the assembled polycation (CD‐PGEA), comprising one β‐cyclodextrin core and two ethanolamine‐functionalized poly(glycidyl methacrylate) arms, to achieve DS‐DOX‐PGEA. The redox‐responsive self‐destruction behavior of DS‐DOX imparts DS‐DOX‐PGEA with a better ability to release anticancer drug DOX, while the low‐toxic hydroxyl‐rich CD‐PGEA brushes can efficiently deliver genes for cancer treatment. Very interestingly, the degradation process of DS‐DOX starts from the outside, while the destruction of the degradable silica (DS) nanoparticles without DOX begins from the center of the nanoparticles. The embedded DOX inside the DS‐DOX nanoparticles can significantly influence the structures and facilitate the cellular uptake and the subsequent gene transfection. The as‐developed DS‐DOX‐PGEA nanostructure with coordinating biodegradability, stimuli‐responsiveness, and controlled release manner might be desirable gene/drug codelivery carriers for clinical cancer treatment.     

pH‐ and NIR Light‐Responsive Micelles with Hyperthermia‐Triggered Tumor Penetration and Cytoplasm Drug Release to Reverse Doxorubicin Resistance in Breast Cancer

The acquisition of multidrug resistance (MDR) is a major hurdle for the successful chemotherapy of tumors. Herein, a novel hybrid micelle with pH and near‐infrared (NIR) light dual‐responsive property is reported for reversing doxorubicin (DOX) resistance in breast cancer. The hybrid micelles are designed to integrate the pH‐ and NIR light‐responsive property of an amphiphilic diblock polymer and the high DOX loading capacity of a polymeric prodrug into one single nanocomposite. At physiological condition (i.e., pH 7.4), the micelles form compact nanostructure with particle size around 30 nm to facilitate blood circulation and passive tumor targeting. Meanwhile, the micelles are quickly dissociated in weakly acidic environment (i.e., pH ≤ 6.2) to release DOX prodrug. When exposed to NIR laser irradiation, the hybrid micelles can trigger notable tumor penetration and cytosol release of DOX payload by inducing tunable hyperthermia effect. In combination with localized NIR laser irradiation, the hybrid micelles significantly inhibit the growth of DOX‐resistant MCF‐7/ADR breast cancer in an orthotopic tumor bearing mouse model. Taken together, this pH and NIR light‐responsive micelles with hyperthermia‐triggered tumor penetration and cytoplasm drug release can be an effective nanoplatform to combat cancer MDR.     

NIR‐Activated Supersensitive Drug Release Using Nanoparticles with a Flow Core

Near infrared (NIR) light‐activated supersensitive drug release via photothermal conversion is of particular interest due to its advantages in spatial and temporal control. However, such supersensitive drug release is rarely reported for polymeric nanoparticles. In this study, polymeric nanoparticles observed with flowable core can achieve NIR‐activated supersensitive drug release under the assistance of photothermal agent. It is demonstrated that only 5 s NIR irradiation (808 nm, 0.3 W cm^?2) leads to 17.8% of doxorubicin (DOX) release, while its release is almost completely stopped when the NIR laser is switched off. In contrast, the control, poly(d ,l ‐lactide) nanoparticles with rigid cores, do not exhibit such supersensitive effect. It is demonstrated that intraparticle temperature is notably increased during photothermal conversion by detecting fluorescein lifetime using a time‐correlated single photon counting (TCSPC) technique, which is the main driving force for such supersensitive drug release from hydrophobic flow core. In contrast, rigid chain of nanoparticular core hinders drug diffusion. Furthermore, such NIR light‐activated supersensitive drug release is demonstrated, which significantly enhances its anticancer efficacy, resulting in overcoming of the resistance of cancer cells against DOX treatment in vitro and in vivo. This simple and highly universal strategy provides a new approach to fabricate NIR light‐activated supersensitive drug delivery systems.     

Porous Silicon Nanoparticles Embedded in Poly(lactic‐co‐glycolic acid) Nanofiber Scaffolds Deliver Neurotrophic Payloads to Enhance Neuronal Growth

Scaffolds made from biocompatible polymers provide physical cues to direct the extension of neurites and to encourage repair of damaged nerves. The inclusion of neurotrophic payloads in these scaffolds can substantially enhance regrowth and repair processes. However, many promising neurotrophic candidates are excluded from this approach due to incompatibilities with the polymer or with the polymer processing conditions. This work provides one solution to this problem by incorporating porous silicon nanoparticles (pSiNPs) that are preloaded with the therapeutic into a polymer scaffold during fabrication. The nanoparticle‐drug‐polymer hybrids are prepared in the form of oriented poly(lactic‐co‐glycolic acid) nanofiber scaffolds. Three different therapeutic payloads are tested: bpV(HOpic), a small molecule inhibitor of phosphatase and tensin homolog (PTEN); an RNA aptamer specific to tropomyosin‐related kinase receptor type B (TrkB); and the protein nerve growth factor (NGF). Each therapeutic is loaded using a loading chemistry that is optimized to slow the rate of release of these water‐soluble payloads. The drug‐loaded pSiNP‐nanofiber hybrids release approximately half of their TrkB aptamer, bpV(HOpic), or NGF payload in 2, 10, and >40 days, respectively. The nanofiber hybrids increase neurite extension relative to drug‐free control nanofibers in a dorsal root ganglion explant assay.     

An Injectable Supramolecular Polymer Nanocomposite Hydrogel for Prevention of Breast Cancer Recurrence with Theranostic and Mammoplastic Functions

The high locoregional breast cancer recurrence rate poses a significant risk for patients' survival. Injecting theranostic drugs‐laden soft tissue‐like hydrogels into the resected breast cavity is a promising strategy to achieve both precisely local therapy of breast cancer and reconstructive mammoplasty. In this work, a robust injectable thermoresponsive supramolecular poly(N‐acryloyl glycinamide‐co‐acrylamide) (PNAm) hydrogel bearing polydopamine (PDA) coated‐gold nanoparticles (AuNPs) and doxorubicin (DOX) is fabricated. The supramolecular polymer nanocomposite (SPN) hydrogels exhibit an excellent photothermal effect arising from PDA‐AuNPs that are tightly fixed to the hydrogel matrix via PDA and amide moieties in the network, built‐in near infrared (NIR) light‐triggered gel–sol transition as well as tunable drug delivery. The PNAm‐PDAAu‐DOX sol driven by prior heating is injected into the cavity of resected cancerous breasts of rats where gelation occurred rapidly while the temperature decreased to body temperature, thereby finely serving as a breast filler. During 4 week of implantation, interval NIR light irradiation can mediate photothermal effect and concertedly controllable DOX release, thus collectively preventing the recurrence of breast cancer. Remarkably, this stable remoldable SPN hydrogel facilitates the breast reconstruction and can be tracked by computed tomography (CT) imaging owing to the intrinsic X‐ray attenuation property of the loaded AuNPs.     

Two‐Stage Size Decrease and Enhanced Photoacoustic Performance of Stimuli‐Responsive Polymer‐Gold Nanorod Assembly for Increased Tumor Penetration

A promising theranostic platform for solid tumors would deliver and release anticancer nanomedicine effectively in tumor cells. However, diverse biological barriers, especially related to the tumor microenvironment, impede these theranostic agents from reaching the tumor cell. Herein, a sequential pH and reduction‐responsive polymer and gold nanorod (AuNR) core–shell assembly to overcome these barriers via a two‐stage size decrease and disassembly of the nanoplatform responding to the specified tumor microenvironment are reported. The tumor uptake of the hybrid nanoparticle (NP) is 14.2% ID g^?1, which is two and four times higher than the noneresponsive hybrid NPs and small AuNR@PEG, respectively. After tumor uptake of the hybrid NPs, the disassembled ultrasmall AuNRs coated with a polymer of polymerized reduction‐responsive doxorubicin (DOX) prodrug monomers penetrate into the solid tumor and lead to localized DOX release in the tumor cell. A linear increase in photoacustic (PA) effects from the PA activating polymer on an AuNR cluster surface indicates a critical role of electromagnetic fields in the AuNR assembly, which is consistent with the theoretical calculation results. Furthermore, the hybrid NP can serve as a promising deep‐tissue PA and surface‐enhanced Raman scattering imaging agent for real‐time in vivo investigation of physiological behaviors and deep tumor penetrating nanotherapy effects.     

Light‐Responsive,Singlet‐Oxygen‐Triggered On‐Demand Drug Release from Photosensitizer‐Doped Mesoporous Silica Nanorods for Cancer Combination Therapy

Smart drug delivery systems with on‐demand drug release capability are rather attractive to realize highly specific cancer treatment. Herein, a novel light‐responsive drug delivery platform based on photosensitizer chlorin e6 (Ce6) doped mesoporous silica nanorods (CMSNRs) is developed for on‐demand light‐triggered drug release. In this design, CMSNRs are coated with bovine serum albumin (BSA) via a singlet oxygen (SO)‐sensitive bis‐(alkylthio)alkene (BATA) linker, and then modified with polyethylene glycol (PEG). The obtained CMSNR‐BATA‐BSA‐PEG, namely CMSNR‐B‐PEG, could act as a drug delivery carrier to load with either small drug molecules such as doxorubicin (DOX), or larger macromolecules such as cis‐Pt (IV) pre‐drug conjugated third generation dendrimer (G3‐Pt), both of which are sealed inside the mesoporous structure of nanorods by BSA coating. Upon 660 nm light irradiation with a rather low power density, CMSNRs with intrinsic Ce6 doping would generate SO to cleave BATA linker, inducing detachment of BSA‐PEG from the nanorod surface and thus triggering release of loaded DOX or G3‐Pt. As evidenced by both in vitro and in vivo experiments, such CMSNR‐B‐PEG with either DOX or G3‐Pt loading offers remarkable synergistic therapeutic effects in cancer treatment, owing to the on‐demand release of therapeutics specifically in the tumor under light irradiation.     

Hollow Mesoporous Zirconia Nanocapsules for Drug Delivery

Hollow mesoporous zirconia nanocapsules (hm‐ZrO₂) with a hollow core/porous shell structure are demonstrated as effective vehicles for anti‐cancer drug delivery. While the highly porous feature of the shell allows the drug, doxorubicin(DOX), to easily pass through between the inner void space and surrounding environment of the particles, the void space in the core endows the nanocapsules with high drug loading capacity. The larger the inner hollow diameter, the higher their DOX loading capacity. A loading of 102% related to the weight of hm‐ZrO₂ is achieved by the nanocapsules with an inner diameter of 385 nm. Due to their pH‐dependent charge nature, hm‐ZrO₂ loaded DOX exhibit pH‐dependent drug releasing kinetics. A lower pH offers a faster DOX release rate from hm‐ZrO₂. Such a property makes the loaded DOX easily release from the nanocapsules when up‐taken by living cells. Although the flow cytometry reveals more uptake of hm‐ZrO₂ particles by normal cells, hm‐ZrO₂ loaded DOX release more drugs in cancer cells than in normal cells, leading to more cytotoxicity toward tumor cells and less cytotoxicity to healthy cells than free DOX.