Self-indicating, fully active pharmaceutical ingredients nanoparticles (FAPIN) for multimodal imaging guided trimodality cancer therapy

Disulfide bonds as a molecular switch of enzyme-activatable anticancer drug precise release for fluorescence imaging and enhancing tumor therapy

Enzyme-activatable drug delivery systems have been developed for cancer diagnosis and therapy. However, targeted intracellular drug delivery is a challenge for precisely tumor imaging and therapy due to the increased stability of copolymer nanoparticles (NPs) is accompanied by a notable decrease in enzyme degradation. Herein, disulfide bond was designed as an enzyme-activatable molecular switch of SS-P(G2)2/DOX NPs. The copolymer NPs consists of polyvinylpyrrolidone (PVP) with disulfide bonds in the center and enzyme-degradable peptide dendrites (Phe-Lys) to form dendritic-linear-dendritic triblock copolymers (TBCs). The amphiphilic TBCs could be split into two identical amphiphilic diblock copolymers (DBCs) by glutathione (GSH) in cancer cells specifically while maintaining the same hydrophilic-lipophilic equilibrium. This structural transformation significantly reduced the stability of copolymer NPs and enhanced sensitivity of DOX release by cathepsin B-activated. Subsequently, the released DOX acted as an indicator of fluorescence imaging and chemotherapy drug for cancer cells. The polymeric NPs achieved excellent drug-loaded stability and prolonged blood circulation in vivo, and realized fluorescence imaging and specific cancer cell killing capabilities by responding to the overexpression of GSH and cathepsin B in tumor cells. Furthermore, the copolymer NPs demonstrated excellent blood compatibility and biosafety. Therefore, a novel strategy based on one tumor marker acting as the switch for another tumor microenvironment responsive drug delivery system could be designed for tumor intracellular imaging and chemotherapy.

Drug-drug conjugates self-assembled nanomedicines triggered photo-/immuno- therapy for synergistic cancer treatments

Although immunotherapies have made progress in cancer treatment, their clinical response rates vary widely and are typically low due to sparse immune cell infiltration (immune "cold") and suppressive tumor immune microenvironment (TIME). A simple yet effective approach that integrates a variety of immune-stimulating and TIME-modulating functions could potentially address this clinical challenge. Herein, we conjugate two small molecules, including a photosensitizer (pyropheophorbide-a, PA) and a Toll-like receptor 7/8 agonist (resiquimod, R848), into prodrug (PA-R848) that self-assembles into PA-R848 esterase responsive nanoparticles (PARE NPs) with 100% drug composition and synergistic photo-/immune- therapeutic effects. In PARE NPs, PA exhibits strong phototherapeutic effects which ablate the primary tumor directly and elicits immunogenic cell death (ICD) to promote the immune response. R848 effectively polarizes the M2-type tumor-associated macrophage (TAM) to M1-type TAM, consequently reversing the "cold" and suppressive TIME when working together with phototherapy. The PARE NPs can efficiently pare down the tumor development by two synergisms, including i) synergistic immunotherapy between ICD and TAM polarization; ii) and the antitumor effects between phototherapy and immunotherapy. On a head-neck squamous cell carcinoma mouse model, PARE NPs combined with PD-1 antibody eliminate primary tumors, and significantly inhibit the progress of distant tumors thanks to the robust antitumor immunity enhanced by the PARE NPs.

Small-molecule nanoprodrug with high drug loading and EGFR, PI3K/AKT dual-inhibiting properties for bladder cancer treatment

Bladder cancer (BCa) is one of the most common malignancies worldwide. Although multiple efforts have been made, the 5-year survival rate of patients with BCa remains unchanged in recent years. Overexpression of the epidermal growth factor receptor (EGFR) is found in ≈74% of BCa tissue specimens; however, current EGFR-based targeted therapies show little benefit for BCa patients, as the EGFR downstream pathways appear to be circumvented by other receptor tyrosine kinases (RTKs). In this study, two natural products are identified, namely triptolide (TPL) and hesperidin (HSP), that target and inhibit the EGFR and its downstream PI3K/AKT pathway in BCa. To synergistically combine triptolide and hesperidin, a succinic acid linker was employed to conjugate them and formed an amphiphilic TPL-HSP EGFR-targeting prodrug (THE), which further self-assembled to generate nanoparticles (THE NPs). These NPs allowed the EGFR-targeted delivery of the triptolide and hesperidin, and simultaneous inhibition of the EGFR and PI3K/AKT both in vitro and in vivo. This study provides a promising EGFR-targeted delivery approach with the dual inhibition of the EGFR and PI3K/AKT, while also exhibiting a high drug loading and low toxicity. Our formulation may be a suitable option to deliver natural products for BCa treatment by EGFR-targeted therapy.

A transformable nanoplatform with multiple therapeutic and immunostimulatory properties for treatment of advanced cancers

Cancer is a complex pathological phenomenon that needs to be treated from different aspects. Herein, we developed a size/charge dually transformable nanoplatform (PDR NP) with multiple therapeutic and immunostimulatory properties to effectively treat advanced cancers. The PDR NPs exhibit three different therapeutic modalities (chemotherapy, phototherapy and immunotherapy) that can be used to effectively treat primary and distant tumors, and reduce recurrent tumors; the immunotherapy is simultaneously activated by three major pathways, including toll-like receptor, stimulator of interferon genes and immunogenic cell death, effectively suppresses the tumor development in combination with an immune checkpoint inhibitor. In addition, PDR NPs show size and charge responsive transformability in the tumor microenvironment, which overcomes various biological barriers and efficiently delivers the payloads into tumor cells. Taking these unique characteristics together, PDR NPs effectively ablate primary tumors, activate strong anti-tumor immunity to suppress distant tumors and reduce tumor recurrence in bladder tumor-bearing mice. Our versatile nanoplatform shows great potential for multimodal treatments against metastatic cancers.

A Supramolecular Assembly Strategy for Hydrophilic Drug Delivery towards Synergistic Cancer Treatment

To improve the drug loading, tumor targeting, and delivery simplicity of hydrophilic drugs, we propose a supramolecular assembly strategy that potentially benefits a wide range of hydrophilic drug delivery. Firstly, we choose a hydrophilic drug (tirapazamine) as a model drug to directly co-assemble with chlorin e6 (Ce6) at different molar ratios, and systematically evaluate the resultant Ce6-tirapazamine nanoparticles (CT NPs) in aspects of size distribution, polydispersity, morphology, optical properties and molecular dynamics simulation. Based on the assembling facts between Ce6 and tirapazamine, we summarize a plausible rule of the supramolecular assembly for hydrophilic drugs. To validate our findings, more drugs with increasing hydrophilicity, such as temozolomide, gemcitabine hydrochloride and 5-azacytidine, successfully co-assemble with Ce6 into nanostructures by following similar assembling behaviors, demonstrating that our assembling rule may guide a wide range of hydrophilic drug delivery. Next, the combination of Ce6 and tirapazamine was chosen as the representative to investigate the anti-tumor activities of the supramolecular assemblies. CT NPs showed synergistic anti-tumor efficacy, increased tumor accumulation and significant tumor progression and metastasis inhibition in tumor-bearing mice. We anticipate that the supramolecular assembly mechanism will provide broad guidance for developing easy-to-make but functional nanomedicines. STATEMENT OF SIGNIFICANCE: Although thousands of nanomedicines have been developed, only a few have been approved for clinical use. The manufacturing complexity significantly hinders the "bench-to-bed" translation of nanomedicines. Hence, we need to rethink how to conduct research on translational nanomedicines by avoiding more and more complex chemistry and complicated nanostructures. Here, we summarize a plausible rule according to multiple supramolecular assembly pairs and propose a supramolecular assembly strategy that can improve the drug loading, tumor targeting, and manufacturing simplicity of nanomedicine for hydrophilic drugs. The supramolecular assembly strategy would guide a broader range of drug delivery to provide a new paradigm for developing easy-to-make but multifunctional nanoformulations for synergistic cancer treatment.

Shield-activated two-way imaging nanomaterials for enhanced cancer theranostics

Smart nanomaterials with stimuli-responsive imaging enhancement have been widely developed to meet the requirements of accurate cancer diagnosis. However, these imaging nanoenhancers tend to be always on during circulation, which significantly increases the background signal when assessing the imaging performance. To improve unfavorable signal-to-noise ratios, an effective way is to shield the noise signal of these nanoprobes in non-targeted areas. Fortunately, there is a natural mutual shielding effect between some imaging nanomaterials, which provides the possibility of designing engineered nanomaterials with imaging quenching between two different components at the beginning. Once in the tumor microenvironment, the two components will present activated dual-mode imaging ability because of their separation, designated as two-way imaging tuning. This review highlights the design and mechanism of a series of engineered nanomaterials with two-way imaging tuning and their latest applications in the fields of cancer magnetic resonance imaging, fluorescence imaging, and their combination. The challenges and future directions for the improvement of these engineered nanomaterials towards clinical transformation are also discussed. This review aims to introduce the special constraint relationships of imaging components and provide scientists with simpler and more efficient nanoplatform construction ideas, promoting the development of engineered nanomaterials with two-way imaging tuning in cancer theranostics.

Stimuli-responsive crosslinked nanomedicine for cancer treatment

Nanomedicines are attractive paradigms to deliver drugs, contrast agents, immunomodulators, and gene editors for cancer therapy and diagnosis. However, the currently developed nanomedicine suffers from poor serum stability, premature drug release, and lack of responsiveness. Crosslinking strategy can be utilized to overcome these shortcomings by employing stimuli-responsive chemical bonds to tightly hold the nanostructure and releasing the payloads spatiotemporally in a highly controlled manner. In this Review, we summarize the recently ingenious design of the stimuli-responsive crosslinked nanomedicines (SCN) in the field of cancer treatment and their advances in circumventing the drawbacks of the conventional drug delivery system. We classify the SCNs into three categories based on the crosslinking strategies, including built-in, on-surface, and inter-particle crosslinking nanomedicines. Thanks to the stimuli-responsive crosslinkages, SCNs are capable of keeping robust stability during systemic circulation. They also respond to the particular tumoral conditions to experience a series of dynamic changes, such as the changes in size, surface charge, targeting moieties, integrity, and imaging signals. These characteristics allow them to efficiently overcome different biological barriers and substantially improve the drug delivery efficiency, tumor-targeting ability, and imaging sensitivities. With the examples discussed, we envision that our perspectives can inspire more attempts to engineer intelligent nanomedicine to achieve effective cancer therapy and diagnosis.

Transformable nanoparticles to bypass biological barriers in cancer treatment

Nanomedicine based drug delivery platforms provide an interesting avenue to explore for the future of cancer treatment. Here we discuss the barriers for drug delivery in cancer therapeutics and how nanomaterials have been designed to bypass these blockades through stimuli responsive transformation in the most recent update. Nanomaterials that address the challenges of each step provide a promising solution for new cancer therapeutics.

Nanotechnology-based combinatorial phototherapy for enhanced cancer treatment

Nanotechnology-based phototherapy has attracted enormous attention to cancer treatment owning to its non-invasiveness, high controllability and accuracy. Given the fast development of anti-tumor strategies, we summarize various examples of multifunctional nanosystems to highlight the recent advances in nanotechnology-based combinatorial phototherapy towards improving cancer treatment. The limitations of the monotherapeutic approach and the superiority of the photo-involved combinatorial strategies are discussed in each part. The future breakthroughs and clinical perspectives of combinatorial phototherapy are also outlooked. Our perspectives may inspire researchers to develop more effective phototherapy-based cancer-treating approaches.

NIR-I Dye-Based Probe: A New Window for Bimodal Tumor Theranostics

Near-infrared (NIR, 650–1700 nm) bioimaging has emerged as a powerful strategy in tumor diagnosis. In particular, NIR-I fluorescence imaging (650–950 nm) has drawn more attention, benefiting from the high quantum yield and good biocompatibility. Since their biomedical applications are slightly limited by their relatively low penetration depth, NIR-I fluorescence imaging probes have been under extensive development in recent years. This review summarizes the particular application of the NIR-I fluorescent dye-contained bimodal probes, with emphasis on related nanoprobes. These probes have enabled us to overcome the drawbacks of individual imaging modalities as well as achieve synergistic imaging. Meanwhile, the application of these NIR-I fluorescence-based bimodal probes for cancer theranostics is highlighted.

Blood-brain barrier penetrating liposomes with synergistic chemotherapy for glioblastoma treatment

Glioblastoma multiforme (GBM) is an aggressive and malignant brain tumor with high mortality. The current treatment strategies are still unsatisfactory for this devastating disease. Here, we developed a glucose-functionalized liposome (gLTP) that co-loads temozolomide (TMZ) and pro-apoptotic peptide (PAP) to achieve synergistic efficacy towards GBM. The gLTP can readily penetrate the blood-brain barrier via the glucose-GLUT1 pathway and release the TMZ and PAP in the cells. The PAP destroys the mitochondria and subsequently depletes ATP generation, making the GBM cells more sensitive to TMZ-mediated chemotherapy. gLTP exhibits the best anti-tumor effect on the subcutaneous brain tumor model compared to other treatments, including a single drug (TMZ or PAP) liposome and TMZ and PAP physical mixture. On the highly aggressive intracranial tumor model, gLTP can readily penetrate the BBB and efficiently deliver the drugs into the brain tumor, leading to striking improvements in total survival compared to the other treatments. This strategy potentially inspires new attempts to design more effective anti-GBM formulations.

Iron-crosslinked Rososome with robust stability and high drug loading for synergistic cancer therapy

Development of liposomal nanomedicine with robust stability, high drug loading and synergistic efficacy is a promising strategy for effective cancer therapy. Here, we present an iron-crosslinked rosmarinic liposome (Rososome) which can load high contents of drugs (including 25.8% rosmarinic acid and 9.04% doxorubicin), keep stable in a high concentration of anionic detergent and exhibit synergistic anti-cancer efficacy. The Rososomes were constructed by rosmarinic acid-lipid conjugates which not only work synergistically with doxorubicin by producing reactive oxygen species but also provide catechol moieties for the iron cross-linkages. The cross-linkages can lock the payloads tightly, endowing the crosslinked Rososome with better stability and pharmacokinetics than its non-crosslinked counterpart. On the syngeneic mouse model of breast cancer, the iron-crosslinked Rososomes exhibit better anticancer efficacy than free rosmarinic acid, doxorubicin, non-crosslinked Rososome and commercial liposomal formulation of doxorubicin (DOXIL). This study introduces a novel strategy for the development of liposomes with robust stability, high drug loading and synergistic anti-cancer efficacy.

A nephrotoxicity-free, iron-based contrast agent for magnetic resonance imaging of tumors

Gadolinium-based contrast agents (GBCAs) are the most widely used T1 contrast agents for magnetic resonance imaging (MRI) and have achieved remarkable success in clinical cancer diagnosis. However, GBCAs could cause severe nephrogenic systemic fibrosis to patients with renal insufficiency. Nevertheless, GBCAs are quickly excreted from the kidneys, which shortens their imaging window and prevents long-term monitoring of the disease per injection. Herein, a nephrotoxicity-free T1 MRI contrast agent is developed by coordinating ferric iron into a telodendritic, micellar nanostructure. This new nano-enabled, iron-based contrast agent (nIBCA) not only can reduce the renal accumulation and relieve the kidney burden, but also exhibit a significantly higher tumor to noise ratio (TNR) for cancer diagnosis. In comparison with Magnevist (a clinical-used GBCA), Magnevist induces obvious nephrotoxicity while nIBCA does not, indicating that such a novel contrast agent may be applicable to renally compromised patients requiring a contrast-enhanced MRI. The nIBCA could precisely image subcutaneous brain tumors in a mouse model and the effective imaging window lasted for at least 24 h. The nIBCA also precisely highlights the intracranial brain tumor with high TNR. The nIBCA presents a potential alternative to GBCAs as it has superior biocompatibility, high TNR and effective imaging window.

Recent advances on small-molecule nanomedicines for cancer treatment

Nanomedicines have made important contributions in the development of cancer therapies due to their tumor selectivity, multifunctionality, and synergistic effect between the payloads. In addition to the required pharmaceutical ingredients, nanomedicines are generally composed of nonpharmaceutical excipients. These excipients generally form a large proportion of the nanomedicine, and they may have potential toxicity and greatly increase the cost for drug development. Small molecule nanomedicines (SMNs) minimize or abandon the excipients and are directly assembled from pharmaceutical ingredients, which can largely improve the drug delivery efficiency and biosafety while also relieving the financial burden of drug development. In this review, we summarize recently developed SMNs that are composed of a single drug, physical mixtures of multiple drugs, drug-drug covalent conjugates, dyes with drugs, photosensitizers with drugs, photosensitizers with peptides, and drugs with peptides. This review focuses on the SMN's applications in cancer treatments, their limitations, and the future development outlook of SMNs. We hope that our insights on SMNs may be helpful to the future of drug development and make nanomedicine more powerful in the battle with cancer. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Robust Photothermal Nanodrugs Based on Covalent Assembly of Nonpigmented Biomolecules for Antitumor Therapy

Photothermal nanodrugs based on biomolecules are critically important for advancing photothermal therapy (PTT). However, constructing photothermal nanodrugs from biomolecules is highly challenging because most biomolecules are inherently nonpigmented. Herein, we synthesize well-defined, uniform photothermal nanodrugs through a covalent assembly approach by using nonpigmented peptides and iridoids as building blocks. The resulting photothermal nanodrugs show broad absorption from the UV to the near-infrared region, high photothermal conversion efficiency along with robust photostability, and selective tumor accumulation, leading to highly efficient tumor ablation via PTT. This work represents the first example of photothermal nanodrugs that can be constructed by using nonpigmented biomolecules as building blocks and thus will conceivably promote the preclinical evaluation and clinical translation of PTT.

Conducting Polymeric Nanocomposites with a Three-Dimensional Co-flow Microfluidics Platform

The nanoprecipitation of polymers is of great interest in biological and medicinal applications. Many approaches are available, but few generalized methods can fabricate structurally different biocompatible polymers into nanosized particles with a narrow distribution in a high-throughput manner. We simply integrate a glass slide, capillary, and metal needle into a simple microfluidics device. Herein, a detailed protocol is provided for using the glass capillary and slides to fabricate the microfluidics devices used in this work. To demonstrate the generality of our nanoprecipitation approach and platform, four (semi)natural polymers—acetalated dextran (Ac-DEX), spermine acetalated dextran (Sp-Ac-DEX), poly(lactic-co-glycolic acid) (PLGA), and chitosan—were tested and benchmarked by the polymeric particle size and polydispersity. More importantly, the principal objective was to explore the influence of some key parameters on nanoparticle size due to its importance for a variety of applications. The polymer concentration, the solvent/non-solvent volume rate/ratio, and opening of the inner capillary were varied so as to obtain polymeric nanoparticles (NPs). Dynamic light scattering (DLS), transmission electron microscopy (TEM), and optical microscopy are the main techniques used to evaluate the nanoprecipitation output. It turns out that the concentration of polymer most strongly determines the particle size and distribution, followed by the solvent/non-solvent volume rate/ratio, whereas the opening of the inner capillary shows a minor effect. The obtained NPs were smooth spheres with adjustable particle diameters and polymer-dependent surface potentials, both negative and positive.

Porphyrin-Based Nanomedicines for Cancer Treatment

As unique molecules with both therapeutic and diagnostic properties, porphyrin derivatives have been extensively employed for cancer treatment. Porphyrins not only show powerful phototherapeutic effects (photodynamic and photothermal therapies), but also exhibit excellent imaging capacities, such as near-infrared fluorescent imaging (NIRFI), magnetic resonance imaging (MRI), photoacoustic imaging (PAI), positron emission tomography (PET), and single-photon emission computed tomography (SPECT). In order to take advantage of their robust phototherapeutic effects and excellent imaging capacities, porphyrins can be used to create nanomedicines with effective therapeutic and precise diagnostic properties for cancer treatment. In this Review, we summarize porphyrin-based nanomedicines which have been developed recently, including porphyrin-based liposomes, micelles, polymeric nanoparticles, peptide nanoparticles, and small-molecule nanoassemblies, and their applications on cancer therapy and diagnosis. The outlook and limitation of porphyrin-based nanomedicines are also reviewed.

A self-delivery system based on an amphiphilic proapoptotic peptide for tumor targeting therapy

A self-delivery system KDH was constructed to realize tumor targeting therapy, and it possessed extraordinary therapeutic efficacy both in vitro and in vivo.

A facile approach to fabricate self-assembled magnetic nanotheranostics for drug delivery and imaging

Superparamagnetic iron oxide (SPIO) nanoparticles have been extensively employed for theranostic applications due to their good biocompatibility and excellent magnetic resonance imaging (MRI) properties. However, these particles typically require surface modification due to their hydrophobic surfaces caused by the oil-phase surfactants used in the fabrication and thus, the drug loading on their surface is usually limited. Here, we provided a novel and facile approach to conveniently perform surface modification of SPIO while simultaneously loading a large amount of drug. By synthesizing an amphiphilic irinotecan-based compound with a hydrophobic tail enabling insertion into the SPIO assembly, an excellent SPIO-based theranostic nanomedicine (SPIO@IR) was produced. SPIO@IR not only extensively improved the drug efficacy, but also allowed visualization by MRI in biological systems.

A polymer-free, biomimicry drug self-delivery system fabricated via a synergistic combination of bottom-up and top-down approaches

Compared to conventional carrier-assistant drug delivery systems (DDSs), drug self-delivery systems (DSDSs) have advantages of unprecedented drug loading capacity, minimized carrier-related toxicity and ease of preparation. However, the colloidal stability and blood circulation time of DSDSs still need to be improved. Here we report on the development of a novel biomimicry drug self-delivery system by the integration of a top-down cell membrane complexing technique into our self-delivery multifunctional nano-platform made from bottom-up approach that contains 100% active pharmaceutical ingredients (API) of Pheophorbide A and Irinotecan conjugates (named PI). Compared to conventional cell membrane coated nanoparticles with polymer framework as core and relatively low drug loading, this system consisting of red blood cell membrane vesicles complexed PI (RBC-PI) is polymer-free with up to 50% API loading. RBC-PI exhibited 10 times higher area under curve in pharmacokinetic study and much lower macrophage uptake compared with the parent PI nanoparticles. RBC-PI retained the excellent chemophototherapeutic effects of the PI nanoparticles, but possessed superior anti-cancer efficacy with prolonged blood circulation, improved tumor delivery, and enhanced photothermal effects in animal models. This system represents a novel example of using cell membrane complexing technique for effective surface modification of DSDSs. This is also an innovative study to form a polymer-free cell membrane nanoparticle complexing with positive surface charged materials. This biomimicry DSDS takes advantages of the best features from both systems to make up for each other's shortcomings and posed all the critical features for an ideal drug delivery system.

Trojan Horse nanotheranostics with dual transformability and multifunctionality for highly effective cancer treatment

Nanotheranostics with integrated diagnostic and therapeutic functions show exciting potentials towards precision nanomedicine. However, targeted delivery of nanotheranostics is hindered by several biological barriers. Here, we report the development of a dual size/charge- transformable, Trojan-Horse nanoparticle (pPhD NP) for delivery of ultra-small, full active pharmaceutical ingredients (API) nanotheranostics with integrated dual-modal imaging and trimodal therapeutic functions. pPhD NPs exhibit ideal size and charge for drug transportation. In tumour microenvironment, pPhD NPs responsively transform to full API nanotheranostics with ultra-small size and higher surface charge, which dramatically facilitate the tumour penetration and cell internalisation. pPhD NPs enable visualisation of biodistribution by near-infrared fluorescence imaging, tumour accumulation and therapeutic effect by magnetic resonance imaging. Moreover, the synergistic photothermal-, photodynamic- and chemo-therapies achieve a 100% complete cure rate on both subcutaneous and orthotopic oral cancer models. This nanoplatform with powerful delivery efficiency and versatile theranostic functions shows enormous potentials to improve cancer treatment.

Size and charge can significantly affect delivery of therapeutic agents to tumours. Here, the authors report on nanoparticles optimised for delivery to the tumour which release smaller particles and change charge in the tumour microenvironment to optimise tumour penetration and cellular uptake.

Biodegradable Cyclomatrix Polyphosphazene Nanoparticles: A Novel pH-Responsive Drug Self-Framed Delivery System

Traditional drug delivery systems suffer from low drug-loading and relatively weak therapeutic efficacy, therefore, development of new drug delivery systems with high-efficiency has become more urgent. In this report, a novel-innovative drug delivery strategy, namely drug self-framed delivery system (DSFDS), is prepared via using anticancer drugs as polymer frame without using any carriers. The drug molecules (exemplified by doxorubicin) containing more than two nucleophilic functional groups (diols/diamines) directly reacted with hexachlorocyclotriphosphazene via mild precipitation polycondensation under ambient conditions, forming biocompatible drug self-framed delivery nanoparticles. Because of the covalent bonding of the drug molecules, DSFD nanoparticles (DSFDs) with super high drug-loading were stable in the circulation during delivery. However, sustained release of drug in the acidic environment within cells endowed DSFDs with long-term anticancer therapeutic efficacy. This strategy is applicable for diverse hydrophilic and hydrophobic drugs and may be a new platform for designing high drug-loading and release-controllable drug delivery systems.

A ZnO-gated porphyrinic metal–organic framework-based drug delivery system for targeted bimodal cancer therapy

A ZnO-gated porMOF-AS1411 nanosystem was prepared and successfully used for drug delivery and synergistic bimodal cancer therapy.