Cetuximab-Polymersome-Mertansine Nanodrug for Potent and Targeted Therapy of EGFR-Positive Cancers.

Targeted nanomedicines particularly armed with monoclonal antibodies are considered to be the most promising advanced chemotherapy for malignant cancers; however, their development is hindered by their instability and drug leakage problems. Herein, we constructed a robust cetuximab-polymersome-mertansine nanodrug (C-P-DM1) for highly potent and targeted therapy of epidermal growth factor receptor (EGFR)-positive solid tumors. C-P-DM1 with a tailored cetuximab surface density of 2 per P-DM1 exhibited a size of ca. 60 nm, high stability with minimum DM1 leakage, glutathione-triggered release of native DM1, and 6.0-11.3-fold stronger cytotoxicity in EGFR-positive human breast (MDA-MB-231), lung (A549), and liver (SMMC-7721) cancer cells (IC50 = 27.1-135.5 nM) than P-DM1 control. Notably, intravenous injection of C-P-DM1 effectively repressed subcutaneous MDA-MB-231 breast cancer and orthotopic A549-Luc lung carcinoma in mice without inducing toxic effects. Strikingly, intratumoral injection of C-P-DM1 completely cured 60% of mice bearing breast tumor without recurrence. This robust cetuximab-polymersome-mertansine nanodrug provides a promising new strategy for targeted treatment of EGFR-positive solid malignancies.

Construction of a Degradation-Free DNA Conjugated Nanoprobe and Its Application in Rapid Field Screening for Sulfur Mustard.

Sulfur mustard (SM) is a notorious blistering chemical warfare agent. Rapid field screening for trace SM is of vital significance for the detection of antiterrorism and timely treatment. Here, a visual assay for SM was constructed on the basis of its inhibition for the G-quadruplexes/hemin DNAzyme. Specifically, multiple guanine (G)-rich single stranded oligonucleotides (ssODN) named S1 (80% of G in the total bases), i.e., the precursor for G-quadruplex, which could oxide tetramethylbenzidine (TMB) to its green product, were conjugated on the nonfouling polymer brush grafted magnetic beads (MB@P(C-H)). SM could specifically alkylate the N7 and O6 sites of G in the S1; thus, it failed to form the DNAzyme based signal reporter. It was demonstrated that the nonfouling P(C-H) interface on the magnetic bead (MB) could protect the conjugated ssODN from nuclease degradation, thus ensuring its well sensing performance in complex samples. Under the optimized conditions, this method achieved good sensitivity and selectivity with a limit of detection (LOD) as low as 0.26 µmol L-1, and the recoveries ranging from 86% to 117% were obtained for different SM spiked real samples. Above all, this method combining low cost and ready operation could be suited for rapid field SM screening in a wide range of environmental matrices.

Apolipoprotein E Peptide-Guided Disulfide-Cross-Linked Micelles for Targeted Delivery of Sorafenib to Hepatocellular Carcinoma.

Sorafenib (SF) is an FDA-approved molecular-targeted drug for treating hepatocellular carcinoma (HCC). SF, however, suffers from poor water solubility, low bioavailability, dose-limiting side effects, and possible drug resistance. Here, we report on apolipoprotein E peptide-decorated disulfide-cross-linked micellar SF (ApoE-Ms-SF) as a targeted and intelligent formulation for HCC therapy. ApoE-Ms-SF was prepared with a good SF loading of 7.0 wt %, small size (37 nm), high stability, and reduction-triggered drug release from poly(ethylene glycol)-b-poly(ε-caprolactone-co-dithiolane trimethylene carbonate)-mefenamate (PEG-P(CL-DTC)-MA) and ApoE-modified ApoE-PEG-P(CL-DTC) block copolymers. MTT assays in low-density lipoprotein receptors (LDLRs) overexpressing SMMC-7721 human liver cancer cells showed ApoE density-dependent antitumor potency of ApoE-Ms-SF, in which 7.5% ApoE led to the best antitumor effect (IC50: 8.5 vs 23.3 µg/mL for free SF). Confocal studies, flow cytometry, western blot, and apoptotic assays illustrated clearly a more efficient uptake of ApoE-Ms than nontargeted Ms by SMMC-7721 cells as well as lower phosphorylated extracellular signal-regulated kinase protein level and better cell apoptosis caused by ApoE-Ms-SF compared with Ms-SF and free SF. ApoE-Ms-SF revealed a long circulation time (elimination half-life = 6.8 h). DiR-loaded ApoE-Ms showed a significantly higher accumulation in SMMC-7721 tumor than the nontargeted counterpart. The therapeutic outcomes in the orthotopic SMMC-7721 tumor models demonstrated that ApoE-Ms-SF reduced SF-associated side effects and brought about enhanced angiogenesis inhibition and tumor apoptosis compared to free SF and Ms-SF controls, leading to a better treatment of HCC.

Nanoagents Based on Poly(ethylene glycol)-b-Poly(l-thyroxine) Block Copolypeptide for Enhanced Dual-Modality Imaging and Targeted Tumor Radiotherapy.

Future healthcare requires development of novel theranostic agents that are capable of not only enhancing diagnosis and monitoring therapeutic responses but also augmenting therapeutic outcomes. Here, a versatile and stable nanoagent is reported based on poly(ethylene glycol)-b-poly(l-thyroxine) (PEG-PThy) block copolypeptide for enhanced single photon emission computed tomography/computed tomography (SPECT/CT) dual-modality imaging and targeted tumor radiotherapy in vivo. PEG-PThy acquired by polymerization of l-thyroxine-N-carboxyanhydride (Thy-NCA) displays a controlled Mn , high iodine content of ≈49.2 wt%, and can spontaneously form 65 nm-sized nanoparticles (PThyN). In contrast to clinically used contrast agents like iohexol and iodixanol, PThyN reveals iso-osmolality, low viscosity, and long circulation time. While PThyN exhibits comparable in vitro CT attenuation efficacy to iohexol, it greatly enhances in vivo CT imaging of vascular systems and soft tissues. PThyN allows for surface decoration with the cRGD peptide achieving enhanced CT imaging of subcutaneous B16F10 melanoma and orthotopic A549 lung tumor. Taking advantages of a facile iodine exchange reaction, 125 I-labeled PThyN enables SPECT/CT imaging of tumors and monitoring of PThyN biodistribution in vivo. Besides, 131 I-labeled and cRGD-functionalized PThyN displays remarkable growth inhibition of the B16F10 tumor in mice (tumor inhibition rate > 89%). These poly(l-thyroxine) nanoparticles provide a unique and versatile theranostic platform for varying diseases.

Hyaluronic Acid-Guided Cerasome Nano-Agents for Simultaneous Imaging and Treatment of Advanced Atherosclerosis.

Early noninvasive screening and regression therapy for vulnerable atherosclerotic plaques remain challenging. In this study, it is aimed to develop a new approach for the active targeting of atherosclerotic plaques with nano-agents to aid imaging and treatment. Biocompatible hyaluronic acid (HA)-guided cerasomes are generated to selectively target CD44-positive cells within the plaque in in vitro studies and in vivo testing in Apoe-/- mice. Rosuvastatin (RST) is encapsulated in the HA-guided cerasome nano-formulation to produce HA-CC-RST, which results in significant plaque regression as compared to treatment with the free drug. Moreover, gadodiamide-loaded HA-CC enhances magnetic resonance images of vulnerable plaques, thereby attaining the goal of improved simultaneous treatment and imaging. Transcriptomic analysis confirms plaque regression with HA-CC-RST treatment, which potentially benefits from the anti-inflammatory effect of RST. In summary, a safe and efficient nano-formulation for the targeted delivery of active agents to atherosclerotic plaques is developed and may be applicable to other diagnostic and therapeutic agents for atherosclerosis treatment.

Selective transferrin coating as a facile strategy to fabricate BBB-permeable and targeted vesicles for potent RNAi therapy of brain metastatic breast cancer in vivo.

Brain metastases are a most disturbing situation for breast cancer patients as there is basically no adequate treatment available. Any potential drug formulation has to be able to cross the blood-brain barrier (BBB) and specific to metastatic brain tumors without causing unacceptable adverse effects. Here, we developed transferrin-functionalized chimeric polymersomes carrying siRNA against polo-like kinase 1 (Tf@TBP-CPs-siPLK1) for treating brain metastatic MDA-MB 231 triple negative breast cancer (TNBC) xenografts in mice. To facilitate the loading of siPLK1, chimaeric polymersomes (CPs) were designed with spermine in the watery core and transferrin-binding peptide (TBP) at the surface, enabling attachment of transferrin after the siRNA loading step and thereby circumventing interference of transferrin with siRNA loading. Tf@TBP-CPs-siPLK1 encapsulating 3.8 wt% siRNA had a mean size of about 50 nm and a neutral zeta potential in phosphate buffer (PB). By virtue of the presence of transferrin, Tf@TBP-CPs demonstrated greatly (ca. 5-fold) enhanced internalization in MDA-MB 231 cells and transcytosis in the endothelial (bEnd.3) monolayer model in vitro as well as markedly improved accumulation in the orthotopically xenografted MDA-MB 231 tumor in the brain in vivo compared with control CPs lacking transferrin, supporting that transferrin mediates efficient BBB penetration and high specificity towards MDA-MB 231 cells. As a result, Tf@TBP-CPs-siPLK1 effectively inhibited tumor progression and prolonged the lifespan of the mice significantly. Selective transferrin coating appears to be a particularly facile strategy to fabricate BBB-permeable and targeted vesicles for potent RNAi therapy of brain metastatic breast cancer.

Transferrin-binding peptide functionalized polymersomes mediate targeted doxorubicin delivery to colorectal cancer in vivo.

Transferrin receptor (TfR) is a promising target validated in the clinical trials for managing various malignancies. Transferrin (Tf) and single chain antibody fragment can target TfR and are typically conjugated to nanomedicines via post-modification, which poses significant production challenges. Here, we report that the polymersomes functionalized with a Tf-binding peptide CGGGHKYLRW (TBP-Ps) can selectively and stably bind Tf and subsequently mediate targeted doxorubicin (Dox) delivery to TfR over-expressing HCT-116 colorectal cancer cells in vitro and in vivo. The Tf surface density of the polymersomes could be controlled by the surface content of TBP. Interestingly, modifying Dox-loaded TBP-Ps with Tf led to greatly increased cellular uptake and inhibitory effect of HCT-116 cells. Tf-bound TBP-Ps demonstrated rapid accumulation in the tumor xenografts in nude mice following i.v. injection. More importantly, Dox-loaded Ps with Tf binding significantly enhanced the antitumor efficacy in mice bearing HCT-116 tumors compared to polymersomes without Tf binding. Surface functionalization of the nanoparticles with Tf-binding peptide provides an appealing strategy in formulating Tf-targeted nanomedicines.

α3ß1 Integrin-Targeting Polymersomal Docetaxel as an Advanced Nanotherapeutic for Nonsmall Cell Lung Cancer Treatment.

Docetaxel (DTX) widely used for treating nonsmall cell lung cancer (NSCLC) patients is associated with dose-limiting side effects, especially neurotoxicity and myelosuppression. Here, we have developed cyclic cNGQGEQc peptide-directed polymersomal docetaxel (cNGQ-PS-DTX) as a targeted and multifunctional formulation for NSCLC. cNGQ-PS-DTX carrying 8.1 wt % DTX had a size of 93 nm, neutral surface charge, high stability, and glutathione-triggered DTX release behavior. Cytotoxicity studies demonstrated a clearly better antitumor activity of cNGQ-PS-DTX in α3ß1 integrin overexpressing A549 human lung cancer cells than free DTX and nontargeted PS-DTX. cNGQ-PS-DTX showed a remarkably high tolerability (over 8 times better than free DTX) and slow elimination in mice. Importantly, cNGQ-PS-DTX exhibited greatly improved tumor accumulation and higher suppression of subcutaneous and orthotopic A549 xenografts as compared to PS-DTX and free DTX controls. α3ß1 integrin-targeting polymersomal docetaxel emerges as an advanced nanotherapeutic for NSCLC treatment.

GE11 peptide-installed chimaeric polymersomes tailor-made for high-efficiency EGFR-targeted protein therapy of orthotopic hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) remains a leading malignancy with a high mortality and little improvement in treatments. Protein drugs though known for their extraordinary potency and specificity have rarely been investigated for HCC therapy owing to lack of appropriate delivery systems. Here, we designed GE11 peptide-installed chimaeric polymersomes (GE11-CPs) for high-efficiency EGFR-targeted protein therapy of orthotopic SMMC-7721 HCC-bearing nude mice. GE11-CPs were assembled from poly(ethylene glycol)-b-poly(trimethylene carbonate-co-dithiolane trimethylene carbonate)-b-poly(aspartic acid) (PEG-P(TMC-DTC)-PAsp) and GE11-functionalized PEG-P(TMC-DTC), which allowed efficient loading and protection of proteins in the watery interior and fine-tuning of GE11 densities at the surface. CPs with short PAsp segments (degree of polymerization (DP) = 5, 10 and 15) exhibited a protein loading efficiency of 60%-72% and glutathione-responsive protein release. Saporin-loaded GE11-CPs had a size of 36 - 62 nm depending on GE11 densities and DP of PAsp. Notably, GE11-CPs with 10% GE11 revealed greatly enhanced uptake in SMMC-7721 cells, boosting the anticancer potency of saporin for over 3-folds compared with non-targeted control (half-maximal inhibitory concentration (IC50) = 11.0 versus 36.3 nM). The biodistribution studies using Cy5-labeled cytochrome C as a model protein demonstrated about 3-fold higher accumulation of GE11-CPs formulation than CPs counterpart in both subcutaneous and orthotopic SMMC-7721 tumor models. Notably, saporin-loaded GE11-CPs revealed low toxicity, effective tumor inhibition and significant improvement of survival rate compared with PBS and non-targeted groups (median survival time: 99 versus 37 and 42 days). EGFR-targeted chimaeric polymersomes carrying proteins appear an interesting HCC treatment modality.

cRGD-decorated biodegradable polytyrosine nanoparticles for robust encapsulation and targeted delivery of doxorubicin to colorectal cancer in vivo.

The clinical success of nanomedicines demands on the development of simple biodegradable nanocarriers that can efficiently and stably encapsulate chemotherapeutics while quickly release the payloads into target cancer cells. Herein, we report that cRGD-decorated biodegradable polytyrosine nanoparticles (cRGD-PTN) boost encapsulation and targeted delivery of doxorubicin (DOX) to colorectal cancer in vivo. The co-assembly of poly(ethylene glycol)-poly(L-tyrosine) (PEG-PTyr) and cRGD-functionalized PEG-PTyr (mol/mol, 80/20) yielded small-sized cRGD-PTN of 70 nm. Interestingly, cRGD-PTN exhibited an ultra-high DOX encapsulation with drug loading contents ranging from 18.5 to 54.1 wt%. DOX-loaded cRGD-PTN (cRGD-PTN-DOX) was highly stable against dilution, serum, and Triton X-100 surfactant, while quickly released DOX in HCT-116 cancer cells, likely resulting from enzymatic degradation of PTyr. Flow cytometry, confocal microscopy and MTT assays displayed that cRGD-PTN-DOX was efficiently internalized into αvß5 overexpressing HCT-116 colorectal cancer cells, rapidly released DOX into the nuclei, and induced several folds better antitumor activity than non-targeted PTN-DOX and clinically used liposomal DOX (Lipo-DOX). SPECT/CT imaging revealed strong tumor accumulation of 125I-labeled cRGD-PTN, which was 2.8-fold higher than 125I-labeled PTN. Notably, cRGD-PTN-DOX exhibited over 5 times better toleration than Lipo-DOX and significantly more effective inhibition of HCT-116 colorectal tumor than non-targeted PTN-DOX control, affording markedly improved survival rate in HCT-116 tumor-bearing mice with depleting side effects at 6 or 12 mg DOX equiv./kg. cRGD-PTN-DOX with great simplicity, robust drug encapsulation and efficient nucleic drug release appears promising for targeted chemotherapy of colorectal tumor.

Iodine-Rich Polymersomes Enable Versatile SPECT/CT Imaging and Potent Radioisotope Therapy for Tumor in Vivo.

Emerging tumor treatment demands high sensitivity and high-spatial resolution diagnosis in combination with targeted therapy. Here, we report that iodine-rich polymersomes (I-PS) enable versatile single-photon emission computed tomography (SPECT)/computed tomography (CT) dual-modal imaging and potent radioisotope therapy for breast cancer in vivo. Interestingly, I-PS could be easily and stably labeled with radioiodine, 125I and 131I. Dynamic light scattering and transmission electron microscopy showed that 125I-PS had a size of 106 nm and vesicular morphology, similar to those of the parent I-PS. Methyl thiazolyl tetrazolium assays displayed that I-PS and 125I-PS were noncytotoxic, whereas 131I-PS caused significant death of 4T1 cells at 5 mg PS/mL with a radioactivity of 12 µCi. Pharmacokinetic and biodistribution studies showed that 125I-PS has a prolonged circulation and distributes mainly in tumor and the reticuloendothelial system. The intravenous injection of 125I-PS to 4T1 murine breast tumor-bearing mice allowed simultaneous high sensitivity and high-spatial resolution imaging of tumor by SPECT and CT, respectively. The therapeutic studies revealed that 131I-PS could effectively retard the growth of 4T1 breast tumor and significantly prolong mice survival time. The hematoxylin and eosin staining assay proved that 131I-PS induced tumor cell death. I-PS emerges as a robust and versatile platform for dual-modal imaging and targeted radioisotope therapy.

Low-toxicity transferrin-guided polymersomal doxorubicin for potent chemotherapy of orthotopic hepatocellular carcinoma in vivo.

Hepatocellular carcinoma (HCC) remains one of the most lethal malignancies. The current chemotherapy with typically low tumor uptake and high toxicity reveals a poor anti-HCC efficacy. Here, we report transferrin-guided polycarbonate-based polymersomal doxorubicin (Tf-Ps-Dox) as a low-toxic and potent nanotherapeutic agent for effective treatment of liver tumor using a transferrin receptor (TfR)-positive human liver tumor SMMC-7721 model. Tf-Ps-Dox was facilely fabricated with small size of ca. 75 nm and varying Tf densities from 2.2% to 7.0%, by postmodification of maleimide-functionalized Ps-Dox (Dox loading content of 10.6 wt%) with thiolated transferrin. MTT assays showed that Tf-Ps-Dox had an optimal Tf surface density of 3.9%. The cellular uptake, intracellular Dox level, and anticancer efficacy of Tf-Ps-Dox to SMMC-7721 cells were inhibited by supplementing free transferrin, which supports that Tf-Ps-Dox is endocytosed through TfR. Interestingly, Tf-Ps-Dox exhibited a high accumulation of 8.5%ID/g (percent injected dose per gram of tissue) in subcutaneous SMMC-7721 tumors, which was 2- and 3-fold higher than that of nontargeted Ps-Dox and clinically used liposomal Dox formulation (Lipo-Dox), respectively. The median survival times of mice bearing orthotopic SMMC-7721 tumors increased from 82, 88 to 96 days when treated with Tf-Ps-Dox at Dox doses from 8, 12 to 16 mg/kg, which was significantly longer than that of Ps-Dox at 8 mg/kg (58 days) and Lipo-Dox at 4 mg/kg (48 days) or PBS (36 days). Notably, unlike Lipo-Dox, no body weight loss and damage to major organs could be discerned for all Tf-Ps-Dox groups, indicating that Tf-Ps-Dox caused low systemic toxicity. This transferrin-dressed polymersomal doxorubicin provides a potent and low-toxic treatment modality for human hepatocellular carcinoma. STATEMENT OF SIGNIFICANCE: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. Vast work has focused on developing HCC-targeted nanotherapeutics. However, none of the nanotherapeutics has advanced to clinics, partly because the ligands used have not been validated in patients. Transferrin (Tf) is a natural ligand for transferrin receptor (TfR) that is overexpressed on cancerous cells, and it is currently under clinical trials (MBP-426 and CALAA-01) for the treatment of solid tumors. We designed Tf-functionalized polymersomal doxorubicin (Tf-Ps-Dox) for targeted therapy of orthotopic SMMC-7721 tumor in nude mice. Tf-Ps-Dox showed potent anti-HCC efficacy and significantly improved survival time with low toxicity as compared with nontargeted Ps-Dox and clinical liposomal Dox (Lipo-Dox). Hence, Tf-Ps-Dox is very appealing for targeted treatment of HCC.

Selective Cell Penetrating Peptide-Functionalized Envelope-Type Chimeric Lipopepsomes Boost Systemic RNAi Therapy for Lung Tumors.

Small interfering RNA (siRNA) is considered a highly specific and potent biotherapeutic that holds tremendous potential for the treatment of various diseases. The clinical translation of siRNA is, however, greatly impeded by the lack of safe and efficient delivery vehicles in vivo. Here, the development of selective cell penetrating peptide (CPP33)-functionalized chimeric lipopepsomes (CPP33-CLP) for efficient encapsulation and selective delivery of polo-like kinase 1 specific siRNA (siPLK1) to orthotopic A549 human lung tumor in vivo is reported. Interestingly, siRNA is tightly encapsulated into CPP33-CLP with a superb encapsulation efficiency of over 95% owing to the thick strong electrostatic interactions. Notably, siPLK1-loaded CPP33-CLP (siPLK1-CPP33-CLP) is selectively internalized by A549 human lung cancer cells, efficiently escapes from endosomes, and swiftly releases siRNA into the cytoplasm, affording a significant sequence-specific gene silencing in vitro. Moreover, siPLK1-CPP33-CLP exhibits prolonged blood circulation, enhanced tumor accumulation, effective suppression of tumor growth, and considerably elevated survival time of orthotopic A549 human lung tumor-bearing nude mice. These chimeric lipopepsomes appear as an attractive and potent nanoplatform for safe and targeted siRNA delivery.

Cyclic RGD-Functionalized and Disulfide-Crosslinked Iodine-Rich Polymersomes as a Robust and Smart Theranostic Agent for Targeted CT Imaging and Chemotherapy of Tumor.

There is tremendous interest in integrating CT imaging with chemotherapy; however, reported iodine-based nanosystems such as nanogels and nano-emulsions display typically reduced contrast coefficient, low drug loading and stability, and poor targetability. Here, cRGD-functionalized disulfide-crosslinked iodine-rich polymersomes (cRGD-XIPs) were designed as a novel, robust and smart theranostic agent and investigated for targeted CT imaging and chemotherapy of malignant tumors. Methods: cRGD-XIPs were prepared from co-self-assembly of poly(ethylene glycol)-b-poly(dithiolane trimethylene carbonate-co-iodinated trimethylene carbonate) (PEG-P(DTC-IC)) and cRGD-PEG-P(DTC-IC) block copolymers. In vitro and in vivo CT contrast effect of cRGD-XIPs was studied using αvß3-overexpressing B16 melanoma as a tumor model in comparison with clinical agent iohexol. The therapeutic efficacy of doxorubicin-loaded cRGD-XIPs (cRGD-XIPs-Dox) to B16 melanoma was investigated and compared with XIPs-Dox (non-targeted), cRGD-IPs-Dox (non-crosslinked) and free Dox. Results: cRGD-XIPs were formed with 55.5 wt.% iodine and ca. 90 nm in diameter. cRGD-XIPs-Dox with a Dox loading of 15.3 wt.% bared superior colloidal stability and reduction-responsive drug release. Notably, blank cRGD-XIPs showed a maximum-tolerated dose (MTD) > 400 mg iodine equiv./kg while cRGD-XIPs-Dox had an MTD > 150 mg Dox equiv./kg, ca. 15-fold improvement over free Dox. cRGD-XIPs revealed superior CT contrast effect and achieved 46.5- and 24.0-fold better enhancement of CT imaging of B16 melanoma than iohexol at 4 h following intratumoral and intravenous injection, respectively. cRGD-XIPs-Dox displayed an elimination half-life of 6.5 h and an elevated accumulation of 6.68% ID/g in the tumors. Furthermore, cRGD-XIPs-Dox was significantly more effective than XIPs-Dox and cRGD-XPs-Dox in inhibiting growth of B16 melanoma model. Conclusion: This proof-of-concept study demonstrates that cRGD-XIPs are a robust, non-toxic and smart polymeric theranostic agent that can not only significantly enhance CT imaging of tumors but also mediate efficient tumor-targeted chemotherapy. XIPs offer a unique and safe platform for theranostic polymersomes that pre-select patients using CT imaging prior to targeted chemotherapy with the same system.

Granzyme B-loaded, cell-selective penetrating and reduction-responsive polymersomes effectively inhibit progression of orthotopic human lung tumor in vivo.

The clinical use of protein therapeutics with intracellular targets is hampered by its in vivo fragility and low cell permeability. Here, we report that cell-selective penetrating and reduction-responsive polymersomes (CPRPs) mediate high-efficiency targeted delivery of granzyme B (GrB) to orthotopic human lung tumor in vivo. Model protein studies using FITC-labeled cytochrome C (FITC-CC) revealed efficient and high protein loading up to 17.2 wt% for CPRPs. FITC-CC-loaded CPRPs exhibited a small size of 82-90 nm, reduction-responsive protein release, as well as greatly enhanced internalization and cytoplasmic protein release in A549 lung cancer cells compared with the non-targeted FITC-CC-loaded RPs control. GrB-loaded CPRPs showed a high potency toward A549 lung cancer cells with a half maximal inhibitory concentration (IC50) of 20.7 nM. Under the same condition, free GrB was essentially non-toxic. Importantly, installing cell-selective penetrating peptide did not alter the circulation time but did enhance tumor accumulation of RPs. Orthotopic A549-Luc lung tumor-bearing nude mice administered with GrB-loaded CPRPs at a dosage of 2.88 nmol GrB equiv./kg showed complete tumor growth inhibition with little body weight loss throughout the treatment period, resulting in significantly improved survival rate over the non-targeted and non-treated controls. These cell-selective penetrating and reduction-responsive polymersomes provide a targeted protein therapy for cancers.

Nanopolymersomes with an Ultrahigh Iodine Content for High-Performance X-Ray Computed Tomography Imaging In Vivo.

Biocompatible and biodegradable nanopolymersomes with an unprecedented iodine content, low viscosity, and iso-osmolality achieve significantly enhanced CT imaging of blood pool and the reticuloendothelial system. Moreover, in subcutaneous and orthotopic tumor models in mice, they show enhanced in vivo imaging when compared to iohexol, a clinically used small-molecule contrast agent.

Microgels with tunable affinity-controlled protein release via desolvation of self-assembled peptide nanofibers.

With a growing number of bioactive protein drugs approved for clinical use each year, there is increasing need for vehicles for localized protein delivery to reduce administered doses, prevent off-target activity, and maintain protein bioactivity. Ideal protein delivery vehicles provide high encapsulation efficiency of bioactive drug, enable fine-tuning of protein release profiles, are biocompatible, and can be administered via minimally-invasive routes. Here we developed an approach to create micron-sized hydrated gels (i.e."microgels") for protein delivery that fulfill these requirements via desolvation of self-assembled ß-sheet peptide nanofibers. Specifically, aqueous solutions of peptide nanofibers were diluted under stirring conditions in a "desolvating agent", such as ethanol, which is miscible with water but poorly solvates peptides. The desolvating agent induced nanofiber physical crosslinking into microgels that retained ß-sheet secondary structure and were stable in aqueous solutions. Microgels did not activate dendritic cells in vitro, suggesting they are biocompatible. Peptide nanofibers and proteins having similar non-solvent immiscibility properties were co-desolvated to produce protein-loaded microgels with loading efficiencies of ∼85%. Encapsulated bioactive proteins rapidly diffused into bulk aqueous media, as expected for hydrated gels. Modifying peptide nanofibers with a protein-binding ligand provided tunable affinity-controlled protein release. Biocompatible microgels formed via desolvation of self-assembled peptide nanofibers are therefore likely to be broadly useful as vehicles for localized delivery of bioactive proteins, as well as other therapeutic molecules.

Photocrosslinkable bioadhesive based on dextran and PEG derivatives.

In this study, a hybrid photopolymeric bioadhesive system consisting of urethane methacrylated dextran (Dex-U) and 3, 4-Dihydroxyphenyl-l-alanine (DOPA) modified three-arm poly (ethylene glycol) s (PEG-DOPAs) was designed. The process of photopolymerization was detected by Photo-Differential Scanning Calorimetry (Photo-DSC). The adhesion strength was evaluated by the lap shear tests. The surface tension of the solutions, burst pressures and the cytotoxicity assays were also investigated. The addition of PEG-DOPAs significantly improved the properties of Dex-U especially in the field of adhesion strength and burst pressure. And materials variation could be tailored to match the demands for tissue repair. Compared to the Dex-U systems, the maximum adhesion strength of the copolymeric system increased from 2.7±0.1 MPa to 4.0±0.6 MPa. Owing to its strong adhesion strength, rapid curing rate and good biocompatibility, such photocrosslinkable hydrogelsa could be applied to the areas of bioadhesive.