Bioreducible Block Copolymers Based on Poly(Ethylene Glycol) and Poly(γ-Benzyl l-Glutamate) for Intracellular Delivery of Camptothecin

Poly(ethylene glycol)-b-poly(γ-benzyl l-glutamate)s bearing the disulfide bond (PEG-SS-PBLGs), which is specifically cleavable in intracellular compartments, were prepared via a facile synthetic route as a potential carrier of camptothecin (CPT). Diblock copolymers with different lengths of PBLG were synthesized by ring-opening polymerization of benzyl glutamate N-carboxy anhydride in the presence of a PEG macroinitiator (PEG-SS-NH2). Owing to their amphiphilic nature, the copolymers formed spherical micelles in an aqueous condition, and their particle sizes (20–125 nm in diameter) were dependent on the block length of PBLG. Critical micelle concentrations of the copolymers were in the range 0.005–0.065 mg/mL, which decreased as the block length of PBLG increased. CPT, chosen as a model anticancer drug, was effectively encapsulated up to 12 wt % into the hydrophobic core of the micelles by the solvent casting method. It was demonstrated by the in vitro optical imaging technique that the fluorescence signal of doxorubicin, quenched in the PEG-SS-PBLG micelles, was highly recovered in the presence of glutathione (GSH), a tripeptide reducing disulfide bonds in the cytoplasm. The micelles released CPT completely within 20 h under 10 mM GSH, whereas only 40% of CPT was released from the micelles in the absence of GSH. From the in vitro cytotoxicity test, it was found that CPT-loaded PEG-SS-PBLG micelles showed higher toxicity to SCC7 cancer cells than CPT-loaded PEG-b-PBLG micelles without the disulfide bond. Microscopic observation demonstrated that the disulfide-containing micelle could effectively deliver the drug into nuclei of SCC7 cells. These results suggest that PEG-SS-PBLG diblock copolymer is a promising carrier for intracellular delivery of CPT

Additional file 1 of In vivo toxicity evaluation of tumor targeted glycol chitosan nanoparticles in healthy mice: repeated high-dose of glycol chitosan nanoparticles potentially induce cardiotoxicity

Additional file 1: Figure S1. Synthetic route to prepare the glycol chitosan and 5β-cholanic acid conjugates. Figure S2. Detail information of average size of different concentrations of CNPs in the mouse serum. Figure S3. Detail information of average size of different concentrations of CNPs in the mouse serum (n=5). Figure S4. Flow cytometric results showing H9C2 cells stained with Annexin V/PI after treatment with CNPs for 24 h. Figure S5. Fluorescence image of major organs from mice treated with 90 mg/kg of CNPs for 7 days. Fluorescence intensities were normalized with the results of Figure 3B and 3C. Figure S6. Excretion profile of Cy5.5-CNPs after 90 mg/kg treatment. The urines were collected from the mice at the indicated time points, followed by analysis of Cy5.5 fluorescence intensity using HPLC. Figure S7. Detail information of hematological parameters on day 7 after single- or multi-dose of 10, 22.5 or 90 mg/kg CNPs. Figure S8. Detail information of complete cell count results on day 7 after single- or multi-dose of 10, 22.5 or 90 mg/kg CNPs (n=5). Figure S9. Uncropped images of western blot results in Figure 5E

Gold-Nanorod-Based Scaffolds for Wound-Healing Applications

Gold-Nanorod-Based Scaffolds for Wound-Healing Application

Gold-Nanorod-Based Scaffolds for Wound-Healing Applications

Controlling local and systemic factors during the wound-healing process, including inflammation, proliferation, and maturation, can play a key role in effective wound healing. It is worth taking advantage of matrix- or scaffold-based therapeutic approaches. Herein, a gold nanorod (GNR)-incorporated poly­(lactic-co-glycolic acid) (PLGA)/poly­(caprolactone) (PCL) scaffold was developed to improve the wound-healing effect by controlling heat shock protein (HSP70) via external light stimulation. The GNR-incorporated scaffold showed no harmful effects on the cells and could stimulate cell proliferation in vitro by generating mild heat generation in a timely manner with laser irradiation. A GNR-incorporated scaffold attached to the wound of mice effectively increased the local temperature to 40 °C after laser irradiation, more effectively promoting HSP70 expression and the wound-healing process compared to that of conventional dressing- and scaffold-treated mice. The GNR-incorporated scaffold and timely control HSP70 expression approach can be used as a promising wound-healing strategy for improving the therapeutic effect

A Comparative Study on Albumin-Binding Molecules for Targeted Tumor Delivery through Covalent and Noncovalent Approach

Various types of albumin-binding molecules have been conjugated to anticancer drugs, and these modified prodrugs could be effective in cancer treatments compared to free anticancer drugs. However, the tumor targeting of albumin-binding prodrugs has not been clearly investigated. Herein, we examined the in vitro and in vivo tumor-targeting efficiency of three different albumin-binding molecules including albumin-binding peptide (DICLPRWGCLW: PEP), fatty acid (palmitic acid: PA), and maleimide (MI), respectively. In order to characterize the different targeting efficiency of albumin-binding molecules, PEP, PA, or MI was chemically labeled with near-infrared fluorescence (NIRF) dye, Cy5.5, in resulting PEP-Cy5.5, PA-Cy5.5, and MI-Cy5.5. These NIRF dye-labeled albumin-binding molecules were physically or chemically bound to albumin via gentle incubation in aqueous conditions in vitro. Notably, PA-Cy5.5 with reversible and multivalent binding affinities formed stable albumin complexes, compared to PEP-Cy5.5 and MI-Cy5.5, confirmed via surface plasmon resonance measurement, gel electrophoresis assay, and albumin-bound column-binding test. In tumor-bearing mice model, the different albumin-binding affinities of PA-Cy5.5, PEP-Cy5.5, and MI-Cy5.5 greatly contributed to their tumor-targeting ability. Even though the binding affinity of PEP-Cy5.5 and MI-Cy5.5 to albumin is higher than that of PA-Cy5.5 in vitro, intravenous PA-Cy5.5 showed a higher tumor-targeting efficiency in tumor-bearing mice compared to that of PEP-Cy5.5 and MI-Cy5.5. The reversible and multivalent affinities of albumin-binding molecules to native serum albumin greatly increased the pharmacokinetics and tumor-targeting efficiency in vivo

Artificial Chemical Reporter Targeting Strategy Using Bioorthogonal Click Reaction for Improving Active-Targeting Efficiency of Tumor

Biological ligands such as aptamer, antibody, glucose, and peptide have been widely used to bind specific surface molecules or receptors in tumor cells or subcellular structures to improve tumor-targeting efficiency of nanoparticles. However, this active-targeting strategy has limitations for tumor targeting due to inter- and intraheterogeneity of tumors. In this study, we demonstrated an alternative active-targeting strategy using metabolic engineering and bioorthogonal click reaction to improve tumor-targeting efficiency of nanoparticles. We observed that azide-containing chemical reporters were successfully generated onto surface glycans of various tumor cells such as lung cancer (A549), brain cancer (U87), and breast cancer (BT-474, MDA-MB231, MCF-7) via metabolic engineering in vitro. In addition, we compared tumor targeting of artificial azide reporter with bicyclononyne (BCN)-conjugated glycol chitosan nanoparticles (BCN–CNPs) and integrin αvβ3 with cyclic RGD-conjugated CNPs (cRGD–CNPs) in vitro and in vivo. Fluorescence intensity of azide-reporter-targeted BCN–CNPs in tumor tissues was 1.6-fold higher and with a more uniform distribution compared to that of cRGD–CNPs. Moreover, even in the isolated heterogeneous U87 cells, BCN–CNPs could bind artificial azide reporters on tumor cells more uniformly (∼92.9%) compared to cRGD–CNPs. Therefore, the artificial azide-reporter-targeting strategy can be utilized for targeting heterogeneous tumor cells via bioorthogonal click reaction and may provide an alternative method of tumor targeting for further investigation in cancer therapy

A Facile, One-Step Nanocarbon Functionalization for Biomedical Applications

Despite their immense potential in biomedicine, carbon nanomaterials suffer from inefficient dispersion and biological activity in vivo. Here we utilize a single, yet multifunctional, hyaluronic acid-based biosurfactant to simultaneously disperse nanocarbons and target single-walled carbon nanotubes (SWCNTs) to CD44 receptor positive tumor cells with prompt uptake. Cellular uptake was monitored by intracellular enzyme-activated fluorescence, and localization of SWCNTs within cells was further confirmed by Raman mapping. In vivo photoacoustic, fluorescence, and positron emission tomography imaging of coated SWCNTs display high tumor targeting capability while providing long-term, fluorescence molecular imaging of targeted enzyme events. By utilizing a single biomaterial surfactant for SWCNT dispersion without additional bioconjugation, we designed a facile technique that brings nanocarbons closer to their biomedical potential

Additional file 1 of Liposomes targeting the cancer cell-exposed receptor, claudin-4, for pancreatic cancer chemotherapy

Additional file 1: Figure S1. Storage stability,measured as changes in the size and PDI of D@C-LPs at 4°C and 25°C. Figure S2. Cytotoxicity of Dox-loaded liposomes against various cancer cell lines. Figure S3. In vivo biodistribution of D@C-LP with pre-treatment of CLDN4 antibody. Figure S4. In vivo therapeutic efficacy of Dox-loaded liposomes in a KPC960 xenograft model. A Photographs of excised tumors after treatment. B Ex vivo fluorescence images. C Changes in body weight in treatment groups over the course of 15 days. D H&E staining of major organsafter 15 days. Figure S5. In vivo therapeutic efficacy of Dox-loaded liposomes in a KPC960 orthotopic model. A Average tumor weights of excised primary tumors. B Average tumor weights of excised metastatic tumors. C Changes in body weight in treatment groups over the course of 24 days. D H&E staining of major organsafter 24 days

Smart Nanocarrier Based on PEGylated Hyaluronic Acid for Cancer Therapy

Tumor targetability and site-specific drug release of therapeutic nanoparticles are key factors for effective cancer therapy. In this study, poly(ethylene glycol) (PEG)-conjugated hyaluronic acid nanoparticles (P-HA-NPs) were investigated as carriers for anticancer drugs including doxorubicin and camptothecin (CPT). P-HA-NPs were internalized into cancer cells (SCC7 and MDA-MB-231) via receptor-mediated endocytosis, but were rarely taken up by normal fibroblasts (NIH-3T3). During in vitro drug release tests, P-HA-NPs rapidly released drugs when incubated with cancer cells, extracts of tumor tissues, or the enzyme Hyal-1, which is abundant in the intracellular compartments of cancer cells. CPT-loaded P-HA-NPs (CPT-P-HA-NPs) showed dose-dependent cytotoxicity to cancer cells (MDA-MB-231, SCC7, and HCT 116) and significantly lower cytotoxicity against normal fibroblasts (NIH-3T3) than free CPT. Unexpectedly, high concentrations of CPT-P-HA-NPs demonstrated greater cytotoxicity to cancer cells than free CPT. An in vivo biodistribution study indicated that P-HA-NPs selectively accumulated into tumor sites after systemic administration into tumor-bearing mice, primarily due to prolonged circulation in the blood and binding to a receptor (CD44) that was overexpressed on the cancer cells. In addition, when CPT-P-HA-NPs were systemically administrated into tumor-bearing mice, we saw no significant increases in tumor size for at least 35 days, implying high antitumor activity. Overall, P-HA-NPs showed promising potential as a drug carrier for cancer therapy

Dual-Modal Imaging-Guided Precise Tracking of Bioorthogonally Labeled Mesenchymal Stem Cells in Mouse Brain Stroke

Noninvasive and precise stem cell tracking after transplantation in living subject is very important to monitor both stem cell destinations and their in vivo fate, which is closely related to their therapeutic efficacy. Herein, we developed bicyclo[6.1.0]­nonyne (BCN)-conjugated glycol chitosan nanoparticles (BCN-NPs) as a delivery system of dual-modal stem cell imaging probes. Near-infrared fluorescent (NIRF) dye Cy5.5 was chemically conjugated to the BCN-NPs, and then oleic acid-coated superparamagnetic iron oxide nanoparticles (OA-Fe3O4 NPs) were encapsulated into BCN-NPs, resulting in Cy5.5-labeled and OA-Fe3O4 NP-encapsulated BCN-NPs (BCN-dual-NPs). For bioorthogonal labeling of human adipose-derived mesenchymal stem cells (hMSCs), first, hMSCs were treated with tetra-acetylated N-azidoacetyl-d-mannosamine (Ac4ManNAz) for generating azide (−N3) groups onto their surface via metabolic glycoengineering. Second, azide groups on the cell surface were successfully chemically labeled with BCN-dual-NPs via bioorthogonal click chemistry in vitro. This bioorthogonal labeling of hMSCs could greatly increase the cell labeling efficiency, safety, and imaging sensitivity, compared to only nanoparticle-derived labeling technology. The dual-modal imaging-guided precise tracking of bioorthogonally labeled hMSCs was tested in the photothrombotic stroke mouse model via intraparenchymal injection. Finally, BCN-dual-NPs-labeled hMSCs could be effectively tracked by their migration from the implanted site to the brain stroke lesion using NIRF/T2-weighted magnetic resonance (MR) dual-modal imaging for 14 days. Our observation would provide a potential application of bioorthogonally labeled stem cell imaging in regenerative medicine by providing safety and high labeling efficiency in vitro and in vivo