Redox-responsive polymer micelles co-encapsulating immune checkpoint inhibitors and chemotherapeutic agents for glioblastoma therapy.

Immunotherapy with immune checkpoint blockade (ICB) for glioblastoma (GBM) is promising but its clinical efficacy is seriously challenged by the blood-tumor barrier (BTB) and immunosuppressive tumor microenvironment. Here, anti-programmed death-ligand 1 antibodies (aPD-L1) are loaded into a redox-responsive micelle and the ICB efficacy is further amplified by paclitaxel (PTX)-induced immunogenic cell death (ICD) via a co-encapsulation approach for the reinvigoration of local anti-GBM immune responses. Consequently, the micelles cross the BTB and are retained in the reductive tumor microenvironment without altering the bioactivity of aPD-L1. The ICB efficacy is enhanced by the aPD-L1 and PTX combination with suppression of primary and recurrent GBM, accumulation of cytotoxic T lymphocytes, and induction of long-lasting immunological memory in the orthotopic GBM-bearing mice. The co-encapsulation approach facilitating efficient antibody delivery and combining with chemotherapeutic agent-induced ICD demonstrate that the chemo-immunotherapy might reprogram local immunity to empower immunotherapy against GBM.

Reduction-responsive polymeric micelles for trans-corneal targeted delivery of microRNA-21-5p and glaucoma-specific gene therapy.

The therapeutic value of microRNA (miRNA) for the treatment of glaucoma has become a focus of attention. However, naked miRNA cannot cross the corneal barrier and reach the target tissue by itself. Thus, the precise transport of miRNA to the target sites is key to the success of gene therapy. Herein, we selected a miRNA, namely miR-21-5p, based on its unique intraocular pressure (IOP) mechano-sensing property. Moreover, a biocompatible polymeric poly(L-lysine) (PLL) micelle conjugated with collagenase and ABCA1 antibody was judiciously constructed to achieve the trans-corneal and target delivery of miR-21-5p to the trabecular meshwork (TM) and Schlemm's canal (SC) tissues inside the eye. The topically administrated PLL micelles as an eye drop successfully crossed the cornea with the help of collagenase and then preferentially accumulated in the target TM/SC tissues under the guidance of the ABCA1 antibody. When endocytosed by TM/SC cells, the PLL micelles could be decomposed in the reductive lysosomal environment to release miR-21-5p for successfully lowering the IOP by activating the miR-21-5p/eNOS/MMP9 signaling axis, which will open new prospects for glaucoma-specific gene therapy.

Recruiting T-Cells toward the Brain for Enhanced Glioblastoma Immunotherapeutic Efficacy by Co-Delivery of Cytokines and Immune Checkpoint Antibodies with Macrophage-Membrane-Camouflaged Nanovesicles.

Immunotherapy with immune checkpoint inhibitors (CPIs) shows promising prospects for glioblastoma multiforme (GBM) but with restricted results, mainly attributed to the immunosuppressive tumor microenvironment (TME) and the limited antibody permeability of the blood-tumor barrier (BTB) in GBM. Here, nanovesicles with a macrophage-mimicking membrane are described, that co-deliver chemotactic CXC chemokine ligand 10 (CXCL10), to pre-activate the immune microenvironment, and anti-programmed death ligand 1 antibody (aPD-L1), to interrupt the immune checkpoint, aiming to enhance the effect of GBM immunotherapy. Consequently, the tumor tropism of the macrophage membrane and the receptor-mediated transcytosis of the angiopep-2 peptide allow the nanovesicle to effectively cross the BTB and target the GBM region, with 19.75-fold higher accumulation of antibodies compared to the free aPD-L1 group. The CPI therapeutic efficacy is greatly enhanced by CXCL10-induced T-cells recruitment with significant expansion of CD8+ T-cells and effector memory T-cells, leading to the elimination of tumor, prolonged survival time, and long-term immune memory in orthotopic GBM mice. The nanovesicles, that relieve the tumor immunosuppressive microenvironment by CXCL10 to enhance aPD-L1 efficacy, may present a promising strategy for brain-tumor immunotherapy.

Visual Investigation of Tumor-Promoting Fibronectin Potentiated by Obesity in Pancreatic Ductal Adenocarcinoma Using an MR/NIRF Dual-Modality Dendrimer Nanoprobe.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease characterized by dense stroma. Obesity is an important metabolic factor that greatly increases PDAC risk and mortality, worsens progression and leads to poor chemotherapeutic outcomes. With omics analysis, magnetic resonance and near-infrared fluorescence (MR/NIRF) dual-modality imaging and molecular functional verification, obesity as an important risk factor is proved to modulate the extracellular matrix (ECM) components and enhance Fibronectin (FN) infiltration in the PDAC stroma, that promotes tumor progression and worsens response to chemotherapy by reducing drug delivery. In the study, to visually evaluate FN in vivo and guide PDAC therapy, an FN-targeted nanoprobe, NP-CREKA, is synthesized by conjugating gadolinium chelates, NIR797 and fluorescein isothiocyanate to a polyamidoamine dendrimer functionalized with targeting peptides. A dual-modality strategy combining MR and NIRF imaging is applied, allowing effective visualization of FN in orthotopic PDAC with high spatial resolution, ideal sensitivity and excellent penetrability, especially in obese mice. In conclusion, the findings provide new insights into the potential of FN as an ideal target for therapeutic evaluation and improving treatment efficacy in PDAC, hopefully improving the specific management of PDAC in lean and obese hosts.

A curcumin-induced assembly of a transferrin nanocarrier system and its antitumor effect.

To increase the solubility and targeting efficiency of curcumin (CCM) to tumors, transferrin (Tf)-CCM nanoparticles (NPs-CCM) with a CCM loading capacity of 5.2% were fabricated by Tf denaturation with hydrochloric acid, a denaturing agent, to open the hydrophobic cavity of Tf. The NPs-CCM were approximately 160 nm in size with a spherical shape. The solubility of the CCM in the nanoparticles was approximately 100,000 times greater than that of CCM alone (11 ng mL-1 vs 1.11 mg mL-1, respectively). The changes in the fluorescence spectra of Tf and 1-(anilinon)-aphthalene-8-sulfonic acid (ANS) in the NP-CCM preparation indicated that the polarity of certain hydrophobic and hydrophilic groups of Tf changed. CCM treatment of A549 cells resulted in a decrease in the mitochondrial membrane potential (MMP) and induced apoptosis through mitochondrial dependence. CCM increased the expression of phosphorylated c-Jun N-terminal kinase (JNK), P38, and extracellular signal-regulated kinase (ERK) but had a weak effect on the expression of nonphosphorylated JNK, P38, and ERK, which showed that the mitogen-activated protein kinase signaling (MAPK) transduction pathway is involved in CCM-mediated apoptosis. The half maximal inhibitory concentration (IC50) of NPs-CCM was higher than that of free CCM in A549 (16.41 ± 0.86 vs 12.51 ± 3.9 (µg mL-1), p = 0.036) and MCF-7 (9.31 ± 0.11 vs 2.44 ± 3.76 (µg mL-1), p < 0.0037) tumor cells, however the former had a greater tumor-targeting in vivo. Without the side effects of polyoxyethylene castor oil/ethanol as solvent, the hemolysis effect of NPs-CCM (0.05-1 mg mL-1) was notably lower than that of free CCM (p < 0.05). It was estimated that the half maximal lethal dose (LD50) of NPs-CCM was approximately two times that of CCM (100 mg kg-1 vs 50 mg kg-1), and the former had many advantages over that of free CCM in terms of lower toxicity and better targeting; thus, NPs-CCM can be administered at higher doses to acquire better antitumor effects than CCM alone, indicating that NPs-CCM are an effective and safe carrier for CCM delivery.

Salt-Inducible Kinase 2-Triggered Release of Its Inhibitor from Hydrogel to Suppress Ovarian Cancer Metastasis.

Salt-inducible kinase 2 (SIK2) is a promising target for ovarian cancer therapy due to its critical role in tumorigenesis and progression. Currently available SIK2 inhibitors have shown remarkable therapeutic effects on ovarian cancers in preclinical studies. However, direct administration of the SIK2 inhibitors may bring significant off-target effect, limiting their clinical applications. In this work, by rational design of a hydrogelator Nap-Phe-Phe-Glu-Glu-Leu-Tyr-Arg-Thr-Gln-Ser-Ser-Ser-Asn-Leu-OH (Nap-S) to coassemble a SIK2 inhibitor HG-9-91-01 (HG), a SIK2-responsive supramolecular hydrogel (Gel Nap-S+HG) for local administration and SIK2-responsive release of HG is reported to efficiently suppress ovarian cancer metastasis. Under the activation of SIK2 overexpressed in ovarian cancers, Nap-S in the hydrogel is phosphorylated to yield hydrophilic Nap-Phe-Phe-Glu-Glu-Leu-Tyr-Arg-Thr-Gln-Ser(H2 PO3 )-Ser-Ser-Asn-Leu (Nap-Sp), triggering the disassembly of the hydrogel and a responsive release of the inhibitor. Cell experiments indicate that sustained release of HG from Gel Nap-S+HG induce a prominent therapeutic effect on cancer cells by inhibiting SIK2 and phosphorylation of their downstream signaling molecules. Animal experiments demonstrate that, compared with those tumor model mice treated with free HG, Gel Nap-S+HG-treatment mice show an enhanced inhibition on ovarian tumor growth and metastasis. It is anticipated that the Gel Nap-S+HG can be applied for ovarian cancer therapy in clinic in the near future.

Size-changeable nanoprobes for the combined radiotherapy and photodynamic therapy of tumor.

PURPOSE: Radiation therapy (RT) and photodynamic therapy (PDT) are promising while challenging in treating tumors. The potential radiation resistance of tumor cells and side effects to healthy tissues restrict their clinical treatment efficacy. Effective delivery of therapeutic agents to the deep tumor tissues would be available for tumor-accurate therapy and promising for the tumor therapy. Thus, developing nanoprobes with effectively delivering radiotherapy sensitizers and photosensitizers to the interior of tumors is needed for the accurate combined RT and PDT of tumor. METHODS: The size-changeable nanoprobes of Gd2O3@BSA-BSA-Ce6 (BGBC) were synthesized with a crosslinking method. Magnetic resonance imaging (MRI) and in vivo near-infrared (NIR) imaging were measured to evaluate the nanoprobes' tumor accumulation and intratumor penetration effect. The tumor suppression effect of combined RT and PDT with these nanoprobes was also studied for the 4T1 bearing Balb/c mice. RESULTS: The nanoprobes BGBC showed high tumor accumulation and disintegrated into small particles responding to the photo-irradiation-produced reactive oxygen species (ROS), allowing for tumor penetration. Abundant radiotherapy sensitizers and photosensitizers were delivered to the deep tumor tissues, which is available for the accurate therapy of tumor. In addition, the BGBC displayed outstanding MRI and fluorescence imaging effects for evaluating the biodistribution and tumor suppression effect of nanoprobes. Consequently, significant tumor suppression effect was obtained based on the accurate tumor treatment with the combined RT and PDT. CONCLUSION: The designed size-changeable nanoprobes BGBC showed excellent tumor accumulation and deep tumor penetration, resulting in a significant tumor suppression effect based on the combined RT and PDT. This study provides a novel strategy for dual delivery of radiotherapy sensitizers and photosensitizers into the deep tumor tissues and is promising for the accurate theranostics of tumor.

Recent advances in biomaterial-boosted adoptive cell therapy.

Adoptive immunotherapies based on the transfer of functional immune cells hold great promise in treating a wide range of malignant diseases, especially cancers, autoimmune diseases, and infectious diseases. However, manufacturing issues and biological barriers lead to the insufficient population of target-selective effector cells at diseased sites after adoptive transfer, hindering effective clinical translation. The convergence of immunology, cellular biology, and materials science lays a foundation for developing biomaterial-based engineering platforms to overcome these challenges. Biomaterials can be rationally designed to improve ex vivo immune cell expansion, expedite functional engineering, facilitate protective delivery of immune cells in situ, and navigate the infused cells in vivo. Herein, this review presents a comprehensive summary of the latest progress in biomaterial-based strategies to enhance the efficacy of adoptive cell therapy, focusing on function-specific biomaterial design, and also discusses the challenges and prospects of this field.

Biodegradable Metal-Organic-Framework-Gated Organosilica for Tumor-Microenvironment-Unlocked Glutathione-Depletion-Enhanced Synergistic Therapy.

The clinical employment of cisplatin (cis-diamminedichloroplatinum(II) (CDDP)) is largely constrained due to the non-specific delivery and resultant serious systemic toxicity. Small-sized biocompatible and biodegradable hollow mesoporous organosilica (HMOS) nanoparticles show superior advantages for targeted CDDP delivery but suffer from premature CDDP leakage. Herein, the smart use of a bimetallic Zn2+ /Cu2+ co-doped metal-organic framework (MOF) is made to block the pores of HMOS for preventing potential leakage of CDDP and remarkably increasing the loading capacity of HMOS. Once reaching the acidic tumor microenvironment (TME), the outer MOF can decompose quickly to release CDDP for chemotherapy against cancer. Besides, the concomitant release of dopant Cu2+ can deplete the intracellular glutathione (GSH) for increased toxicity of CDDP as well as catalyzing the decomposition of intratumoral H2 O2 into highly toxic •OH for chemodynamic therapy (CDT). Moreover, the substantially reduced GSH can also protect the yielded •OH from scavenging and thus greatly improve the •OH-based CDT effect. In addition to providing a hybrid HMOS@MOF nanocarrier, this study is also expected to establish a new form of TME-unlocked nanoformula for highly efficient tumor-specific GSH-depletion-enhanced synergistic chemotherapy/chemodynamic therapy.

Conjugation of glucosylated polymer chains to checkpoint blockade antibodies augments their efficacy and specificity for glioblastoma.

Because of the blood-tumour barrier and cross-reactivity with healthy tissues, immune checkpoint blockade therapy against glioblastoma has inadequate efficacy and is associated with a high risk of immune-related adverse events. Here we show that anti-programmed death-ligand 1 antibodies conjugated with multiple poly(ethylene glycol) (PEG) chains functionalized to target glucose transporter 1 (which is overexpressed in brain capillaries) and detaching in the reductive tumour microenvironment augment the potency and safety of checkpoint blockade therapy against glioblastoma. In mice bearing orthotopic glioblastoma tumours, a single dose of glucosylated and multi-PEGylated antibodies reinvigorated antitumour immune responses, induced immunological memory that protected the animals against rechallenge with tumour cells, and suppressed autoimmune responses in the animals' healthy tissues. Drug-delivery formulations leveraging multivalent ligand interactions and the properties of the tumour microenvironment to facilitate the crossing of blood-tumour barriers and increase drug specificity may enhance the efficacy and safety of other antibody-based therapies.

Enzymatically Transformable Polymersome-Based Nanotherapeutics to Eliminate Minimal Relapsable Cancer.

Prevention of metastatic and local-regional recurrence of cancer after surgery remains difficult. Targeting postsurgical premetastatic niche and microresiduals presents an excellent prospective opportunity but is often challenged by poor therapeutic delivery into minimal residual tumors. Here, an enzymatically transformable polymer-based nanotherapeutic approach is presented that exploits matrix metalloproteinase (MMP) overactivation in tumor-associated tissues to guide the codelivery of colchicine (microtubule-disrupting and anti-inflammatory agent) and marimastat (MMP inhibitor). The dePEGylation of polymersomes catalyzed by MMPs not only exposes the guanidine moiety to improve tissue/cell-targeting/retention to increase bioavailability, but also differentially releases marimastat and colchicine to engage their extracellular (MMPs) and intracellular (microtubules) targets of action, respectively. In primary tumors/overt metastases, the vasculature-specific targeting of nanotherapeutics can function synchronously with the enhanced permeability and retention effect to deter malignant progression of metastatic breast cancer. After the surgical removal of large primary tumors, nanotherapeutic agents are localized in the premetastatic niche and at the site of the postsurgical wound, disrupting the premetastatic microenvironment and eliminating microresiduals, which radically reduces metastatic and local-regional recurrence. The findings suggest that nanotherapeutics can safely widen the therapeutic window to resuscitate colchicine and MMP inhibitors for other inflammatory disorders.

Stimuli-Responsive Polymeric Nanoplatforms for Cancer Therapy.

Polymeric nanoparticles have been widely used as carriers of drugs and bioimaging agents due to their excellent biocompatibility, biodegradability, and structural versatility. The principal application of polymeric nanoparticles in medicine is for cancer therapy, with increased tumor accumulation, precision delivery of anticancer drugs to target sites, higher solubility of pharmaceutical properties and lower systemic toxicity. Recently, the stimuli-responsive polymeric nanoplatforms attracted more and more attention because they can change their physicochemical properties responding to the stimuli conditions, such as low pH, enzyme, redox agents, hypoxia, light, temperature, magnetic field, ultrasound, and so on. Moreover, the unique properties of stimuli-responsive polymeric nanocarriers in target tissues may significantly improve the bioactivity of delivered agents for cancer treatment. This review introduces stimuli-responsive polymeric nanoparticles and their applications in tumor theranostics with the loading of chemical drugs, nucleic drugs and imaging molecules. In addition, we discuss the strategy for designing multifunctional polymeric nanocarriers and provide the perspective for the clinical applications of these stimuli-responsive polymeric nanoplatforms.

Targeted Dual Small Interfering Ribonucleic Acid Delivery via Non-Viral Polymeric Vectors for Pulmonary Fibrosis Therapy.

Inhibiting the myofibroblast differentiation of lung-resident mesenchymal stem cells (LR-MSCs) is a promising yet challenging approach for pulmonary fibrosis (PF) therapy. Here, micelles formed by a graft copolymer of multiple PEGs modified branched polyethylenimine are used for delivering runt-related transcription factor-1 (RUNX1) small interfering RNA (siRNA) (siRUNX1) to the lung, aiming to inhibit the myofibroblast differentiation of LR-MSCs. LR-MSC targeting is achieved by functionalizing the micelle surface with an anti-stem-cell antigen-1 antibody fragment (Fab'). Consequently, therapeutic benefits are obtained by successful suppression of myofibroblast differentiation of LR-MSCs in bleomycin-induced PF model mice treated with siRUNX1-loaded micelles. Furthermore, an excellent synergistic effect of PF therapy is achieved for this micelle system loaded siRUNX1 and glioma-associated oncogene homolog-1 (Gli1) small interfering RNA (siGli1), a traditional anti-PF siRNA of glioma-associated oncogene homolog-1. Hence, this work not only provides RUNX1 as a novel PF therapeutic target, but also as a promising dual siRNA-loaded nanocarrier system for the therapy of PF.

Co-delivery of siPTPN13 and siNOX4 via (myo)fibroblast-targeting polymeric micelles for idiopathic pulmonary fibrosis therapy.

Rationale: (Myo)fibroblasts are the ultimate effector cells responsible for the production of collagen within alveolar structures, a core phenomenon in the pathogenesis of idiopathic pulmonary fibrosis (IPF). Although (myo)fibroblast-targeted therapy holds great promise for suppressing the progression of IPF, its development is hindered by the limited drug delivery efficacy to (myo)fibroblasts and the vicious circle of (myo)fibroblast activation and evasion of apoptosis. Methods: Here, a dual small interfering RNA (siRNA)-loaded delivery system of polymeric micelles is developed to suppress the development of pulmonary fibrosis via a two-arm mechanism. The micelles are endowed with (myo)fibroblast-targeting ability by modifying the Fab' fragment of the anti-platelet-derived growth factor receptor-α (PDGFRα) antibody onto their surface. Two different sequences of siRNA targeting protein tyrosine phosphatase-N13 (PTPN13, a promoter of the resistance of (myo)fibroblasts to Fas-induced apoptosis) and NADPH oxidase-4 (NOX4, a key regulator for (myo)fibroblast differentiation and activation) are loaded into micelles to inhibit the formation of fibroblastic foci. Results: We demonstrate that Fab'-conjugated dual siRNA-micelles exhibit higher affinity to (myo)fibroblasts in fibrotic lung tissue. This Fab'-conjugated dual siRNA-micelle can achieve remarkable antifibrotic effects on the formation of fibroblastic foci by, on the one hand, suppressing (myo)fibroblast activation via siRNA-induced knockdown of NOX4 and, on the other hand, sensitizing (myo)fibroblasts to Fas-induced apoptosis by siRNA-mediated PTPN13 silencing. In addition, this (myo)fibroblast-targeting siRNA-loaded micelle did not induce significant damage to major organs, and no histopathological abnormities were observed in murine models. Conclusion: The (myo)fibroblast-targeting dual siRNA-loaded micelles offer a potential strategy with promising prospects in molecular-targeted fibrosis therapy.

Zwitterionic micelles efficiently deliver oral insulin without opening tight junctions.

Oral delivery of protein drugs is considered a life-changing solution for patients who require regular needle injections. However, clinical translation of oral protein formulations has been hampered by inefficient penetration of drugs through the intestinal mucus and epithelial cell layer, leading to low absorption and bioavailability, and safety concerns owing to tight junction openings. Here we report a zwitterionic micelle platform featuring a virus-mimetic zwitterionic surface, a betaine side chain and an ultralow critical micelle concentration, enabling drug penetration through the mucus and efficient transporter-mediated epithelial absorption without the need for tight junction opening. This micelle platform was used to fabricate a prototype oral insulin formulation by encapsulating a freeze-dried powder of zwitterionic micelle insulin into an enteric-coated capsule. The biocompatible oral insulin formulation shows a high oral bioavailability of >40%, offers the possibility to fine tune insulin acting profiles and provides long-term safety, enabling the oral delivery of protein drugs.

Dual-Sensitive Nanomicelles Enhancing Systemic Delivery of Therapeutically Active Antibodies Specifically into the Brain.

Delivering therapeutic antibodies into the brain across the blood-brain barrier at a therapeutic level is a promising while challenging approach in the treatment of neurological disorders. Here, we present a polymeric nanomicelle (PM) system capable of delivering therapeutically effective levels of 3D6 antibody fragments (3D6-Fab) into the brain parenchyma for inhibiting Aß aggregation. PM assembly was achieved by charge-converting 3D6-Fab through pH-sensitive citraconylation to allow complexation with reductive-sensitive cationic polymers. Brain targeting was achieved by functionalizing the PM surface with glucose molecules to allow interaction with recycling glucose transporter (Glut)-1 proteins. Consequently, 41-fold enhanced 3D6-Fab accumulation in the brain was achieved by using the PM system compared to free 3D6-Fab. Furthermore, therapeutic benefits were obtained by successfully inhibiting Aß1-42 aggregation in Alzheimer's disease mice systemically treated with 3D6-Fab-loaded glucosylated PM. Hence, this nanocarrier system represents a promising method for effectively delivering functional antibody agents into the brain and treating neurological diseases.

Nanomaterial-based blood-brain-barrier (BBB) crossing strategies.

Increasing attention has been paid to the diseases of central nervous system (CNS). The penetration efficiency of most CNS drugs into the brain parenchyma is rather limited due to the existence of blood-brain barrier (BBB). Thus, BBB crossing for drug delivery to CNS remains a significant challenge in the development of neurological therapeutics. Because of the advantageous properties (e.g., relatively high drug loading content, controllable drug release, excellent passive and active targeting, good stability, biodegradability, biocompatibility, and low toxicity), nanomaterials with BBB-crossability have been widely developed for the treatment of CNS diseases. This review summarizes the current understanding of the physiological structure of BBB, and provides various nanomaterial-based BBB-crossing strategies for brain delivery of theranostic agents, including intranasal delivery, temporary disruption of BBB, local delivery, cell penetrating peptide (CPP) mediated BBB-crossing, receptor mediated BBB-crossing, shuttle peptide mediated BBB-crossing, and cells mediated BBB-crossing. Clinicians, biologists, material scientists and chemists are expected to be interested in this review.

Correction: A photo-inducible protein-inorganic nanoparticle assembly for active targeted tumour theranostics.

Correction for 'A photo-inducible protein-inorganic nanoparticle assembly for active targeted tumour theranostics' by Jinbing Xie, Gang Han et al., Nanoscale, 2019, 11, 6136-6144.

A photo-inducible protein-inorganic nanoparticle assembly for active targeted tumour theranostics.

The assembly of protein-inorganic nanoparticles is an important yet challenging approach that is utilized to develop functional materials in numerous areas, such as bio-catalysis, drug delivery, and biosensing. In this study, we report on a facile, photo-inducible self-assembly method to generate protein-inorganic hybrid nanoplatforms. More specifically, photo-treated disulfide bond rich proteins of lysozyme (LYS) were able to be used as host materials in order to encapsulate nanoparticles (i.e., as-synthesized hydrophobic NIR quantum dots (QDs)) and anti-cancer small molecule drugs (i.e., paclitaxel (PTX)), constructing functional theranostic protein-inorganic hybrid nanoparticles. The modification of the functional polymer of cRGD-PEG contributes to the active tumour targeting characteristic of this protein-inorganic nanocarrier. This novel PTX loaded protein-inorganic hybrid nanoplatform showed high tumour homing accumulation as well as effective tumour inhibition. We believe that this general approach represents a new direction for the development of a photo-induced assembly of protein-inorganic nanoparticles towards versatile applications in both materials science and biomedical fields.

Intracellular targeted delivery of quantum dots with extraordinary performance enabled by a novel nanomaterial design.

Quantum dots (QDs) have emerged as a major class of fluorescent probes with unique optical properties, but applying QDs for imaging specific intracellular entities in live cells has been hindered by the poor performance of targeted intracellular delivery of QDs due to various cellular transport barriers. We describe a novel QD nanoprobe design, which is termed a cosolvent-bare hydrophobic QD-biomolecule (cS-bQD-BM, or 'SDot' for short), combining a cosolvent, a bare hydrophobic nanoparticle surface, ultrasmall size and biomolecular function. SDots show extraordinary intracellular targeting performance with the nucleus as the model target, including near-perfect specificity, excellent efficiency and reproducibility, high-throughput ability, minimal toxicity, and ease of operation, as well as superb optical properties and colloidal stability. We introduce integrated single-particle tracking and pair-correlation function analysis of a spinning-disk confocal microscope platform (iSPT-pCF-SDCM) to study SDot's cellular transport. Endocytosed SDots can undergo a highly potent and noninvasive process of vesicle escape, yielding complete vesicle escape with no serious vesicle disruption. We exploit SDots' unprecedented ability to overcome cellular transport barriers to enhance drug and macromolecule delivery.