Mineralising and antibacterial effects of modified calcium phosphate treatment on human root cementum.

BACKGROUND: Aging population will lead to the increase of incidence of root caries globally. The clinical management of root caries is challenging due to the difficulty in moisture isolation. The root caries is caused by the release of organic acids from cariogenic bacteria which results in the dissolution of cementum and dentin of the root. The purpose of this study is to study the efficacy of modified saturated calcium phosphate solution (CaP) supplement with zinc (Zn(2+)) and/or fluoride (F(-)) in providing root cementum surfaces less susceptible to acid dissolution and bacterial colonization. METHODS: Human root cementum sections from extracted premolars were treated with three modified calcium phosphate solutions (M/A-CaPs) respectively: (A) CaP-F/Zn, supplemented with F(-) and Zn(2+); (B) CaP-F, supplemented with F(-) only; (C) CaP-Zn, supplemented with Zn(2+) only. The surface characteristics of treated cementum sections were investigated using scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FT-IR). Following the acid attack and Streptococcus mutans challenge, M/A-CaPs treated cementum surfaces were analysed using inductive coupled plasma (ICP) and SEM respectively. RESULTS: Compared with the control group, M/A-CaPs treated cementum presented significant improvements in resistance to acid dissolution and bacterial colonization. Among M/A-CaPs, the CaP-F/Zn treated cementum surfaces released the lowest amount of Ca(2+) ions (2.11 ± 0.51 ppm) upon acid challenge (n = 3, p < 0.01) and also presented the most significant inhibiting effect against the colonization of S. mutans (n = 180, p < 0.05). CONCLUSIONS: Saturated calcium phosphate solution CaP supplemented with both F(-) and Zn(2+) could be applied as an effective coating material providing acid resistance and antibacterial property on cementum surfaces. The modified calcium phosphate-based solution could be a new treatment strategy to prevent the development of root caries and arrest the further progression of root caries.

Preparation of pH-stimuli-responsive PEG-TGA/TGH-capped CdTe QDs and their application in cell labeling.

A pH-sensitive and double functional nanoprobe was designed and synthesized in a water-soluble system using thioglycolic acid (TGA) and mercapto-acetohydrazide (TGH) as the stabilizers. TGA is biocompatible because the carboxyl group is easily linked to biological macromolecules. At the same time, the hydrazide on TGH reacts with the aldehyde on poly(ethylene glycol) (PEG) and forms a hydrazone bond. The hydrazone bond ruptured at specific pH values and exhibited pH-stimuli-responsive characteristics. As an optical imaging probe, the PEG-TGA/TGH-capped CdTe quantum dots (QDs) had high quality, with a fluorescence efficiency of 25-30%, and remained stable for at least five months. This pH-responsive factor can be used for the effective release of CdTe QDs under the acidic interstitial extracellular environment of tumor cells. This allows the prepared pH-stimuli-responsive nanoprobes to show fluorescence signals for use in cancer cell imaging.

Phase 1 study of the liposomal formulation of eribulin (E7389-LF): Results from the breast cancer expansion cohort.

BACKGROUND: A liposomal formulation of eribulin, E7389-LF, may provide improved pharmacokinetics and allow increased access to tumour tissues. This expansion of a phase 1 study assessed the safety and efficacy of E7389-LF in patients with human epidermal growth factor receptor type 2-negative metastatic breast cancer. METHODS: Patients received E7389-LF 2.0 mg/m2 every three weeks. Tumour assessments were conducted every six weeks by the investigator by Response Evaluation Criteria in Solid Tumours v1.1. All adverse events were monitored and recorded. Serum biomarker assessments were conducted. RESULTS: Of 28 patients included, 75.0% had hormone receptor-positive breast cancer (HR+ BC) and 25.0% had triple-negative breast cancer (TNBC). The most common grade ≥3 treatment-related treatment-emergent adverse events included neutropenia (67.9%), leukopenia (42.9%), thrombocytopenia (32.1%), and febrile neutropenia (25.0%). Rates of neutropenia and febrile neutropenia were lower among patients who received prophylactic pegfilgrastim. Objective response rate was 35.7% (95% confidence interval [CI]: 18.6-55.9) for all patients and 42.9% (95% CI: 21.8-66.0) for patients with HR+ BC. Median progression-free survival was 5.7 months (95% CI: 3.9-8.3). The median overall survival was 18.3 months (95% CI: 13.2-not estimable). Among the 54 biomarkers assessed, 27, including 5 of 7 vascular markers, were significantly altered by E7389-LF treatment from baseline to any time point. CONCLUSION: E7389-LF was tolerable and favourable antitumour activity was observed, particularly in patients with HR+ BC. Prophylactic pegfilgrastim can be considered in patients at high risk for neutropenia and febrile neutropenia. GOV NUMBER: NCT03207672.

Dose Escalation Data from the Phase 1 Study of the Liposomal Formulation of Eribulin (E7389-LF) in Japanese Patients with Advanced Solid Tumors.

PURPOSE: We report the dose-escalation part of a phase I study of liposomal eribulin (E7389-LF) in Japanese patients with advanced solid tumors and no alternative standard therapy. PATIENTS AND METHODS: Patients ≥20 years old were enrolled. E7389-LF doses of 1.0 to 1.5 mg/m2 once every two weeks (Q2W) or 1.0 to 2.5 mg/m2 once every three weeks (Q3W) were planned. The primary objective was to determine the MTD by evaluating dose-limiting toxicities (DLT). Secondary objectives included safety/tolerability assessments, objective response rate (ORR), and progression-free survival; serum biomarker assessment was an exploratory objective. RESULTS: Twenty-one patients were enrolled and treated; 12 in the Q3W group (1.0 mg/m2, n = 3; 1.5 mg/m2, n = 3; 2.0 mg/m2, n = 6) and 9 in the Q2W group (1.0 mg/m2, n=3; 1.5 mg/m2, n = 6). The Q3W and Q2W MTDs were 2.0 mg/m2 and 1.5 mg/m2, respectively. One patient receiving 2.0 mg/m2 Q3W had a DLT of grade 3 febrile neutropenia. The most common grade 3 treatment-emergent adverse events were neutropenia (66.7% in Q3W and Q2W) and leukopenia (Q3W, 58.3%; Q2W, 33.3%). One patient in the Q3W group (2.0 mg/m2) and 3 in the Q2W group (1.0 mg/m2, n = 1; 1.5 mg/m2, n = 2) achieved a partial response [overall ORR, 19.0%; 95% confidence interval (CI), 5.4-41.9]. Endothelial [TEK receptor tyrosine kinase (TEK), intercellular adhesion molecule 1 (ICAM1), vascular endothelial growth factor receptor 3 (VEGFR3), platelet/endothelial cell adhesion molecule 1 (PECAM1)], vasculature (collagen IV), and immune-related [interferon gamma (IFNγ), C-X-C motif chemokine ligand 11 (CXCL11), C-X-C motif chemokine ligand 10 (CXCL10)] biomarker levels were increased. CONCLUSIONS: E7389-LF was well tolerated at 2.0 mg/m2 Q3W and 1.5 mg/m2 Q2W. Considering the toxicity profile of both regimens, the recommended dose was 2.0 mg/m2 Q3W. Expansion cohorts are ongoing.

A multiple environment-sensitive prodrug nanomicelle strategy based on chitosan graftomer for enhanced tumor therapy of gambogic acid.

A novel multiple environment-sensitive polymeric prodrug of gambogic acid (GA) based on chitosan graftomer was fabricated for cancer treatment. Folic acid-chitosan conjugates was complexed with thermosensitive amine terminated poly-N-isopropylacrylamide (NH2-PNIPAM) to develop FA-CSPN. Gambogic acid was conjugated with the graftomer via esterification to achieve high drug-loading capacity and controlled drug release. The resulting amphiphilic prodrug, O-(gambogic acid)-N-(folic acid)-N'-(NH2-PNIPAM) chitosan graftomer (GFCP), could self-assemble into micelles. As expected, the micelles were stable and biocompatible, featuring pH-, esterase- and temperature-dependent manner of drug release. Moreover, the anticancer effect studies of GFCP micelles were performed using a tumor-bearing mouse model and cellular assays (tumor cell uptake assay, cytotoxicity and tumor-sphere penetration). Collectively, GFCP micelles show both potential in vivo and in vitro in improving the anticancer effectiveness of GA owing to high loading capacity, targeted tumor accumulation, and multiple tumor microenvironmental responsiveness.

Novel ß-1,3-d-glucan porous microcapsule enveloped folate-functionalized liposomes as a Trojan horse for facilitated oral tumor-targeted co-delivery of chemotherapeutic drugs and quantum dots.

In this study, a new type of ß-1,3-d-glucan porous microcapsule (GPM)-enveloped and folate conjugated chitosan-functional liposome (FCL), FCL@GPM, was developed for the potential oral co-delivery of chemotherapeutic drugs and quantum dots (QDs) with facilitated drug absorption and antitumor efficacy. In this dual-particulate system, multiple FCLs serve as the cores for effective loading, folate-mediated tumor-targeting, facilitated intracellular accumulation, and pH-responsive controlled release of chemotherapeutic agents, while a GPM acts as the shell for affording macrophage-mediated tumor selectivity. Gefitinib (GEF) was selected as a chemotherapeutic agent, while acid degradable ZnO QDs were selected due to their dual role as an anticancer agent for synergistic chemotherapy and as a fluorescent probe for potential cancer cellular imaging. The GEF and ZnO QD co-loaded FCL@GPMs (GEF/ZnO-FCL@GPMs) exhibited a prolonged release manner with limited release before uptake by intestinal cells. Furthermore, Peyer's patch uptake, macrophage uptake, cytotoxicity, and biodistribution of FCL@GPMs were tested. In addition, GEF and ZnO QD co-loaded FCLs (GEF/ZnO-FCLs) not only have a tumor acidity responsive release property, but also induce a superior cytotoxicity on cancer cells as compared to GEF. Moreover, a 1.75-fold increase in the bioavailability of GEF delivered from GEF/ZnO-FCL@GPMs as compared to its trademarked drug (Iressa®). As a result, GEF/ZnO-FCL@GPMs exerted a superior antitumor efficacy (1.47-fold) as compared to the trademarked drug in mice. Considered together, the developed FCL@GPMs, combining the unique physicochemical and biological benefits of FCLs and GPMs, possess great potential as an efficient delivery system for the co-delivery of chemotherapeutic agents and quantum dots.

Preparation of carbon dots from waste cellulose diacetate as a sensor for tetracycline detection and fluorescence ink.

As one type of the solid wastes, the increasing contamination of waste cellulose diacetate (CDA) from discarded cigarette filters is a growing problem worldwide. Finding a facile and suitable approach to convert the CDA into value-added materials is of significance. Herein, we reported a green, simple and effective method to reuse CDA as precursor for preparing fluorescence N-doped carbon dots (N-CDs) via one-pot hydrothermal carbonization in aqueous solution with low-cost ammonium hydroxide as the passivation agent. The N-CDs showed a quantum yield up to 22.4% with a maximum emission at 415 nm and excitation at 320 nm. Interestingly, the N-CDs exhibited high selectivity toward tetracycline (TC) as their fluorescence was obviously quenched by TC as a result of inner-filter effect. A linear relationship was fabricated over concentration range of 0-80 µM with a detection limit of 0.06 µM. Moreover, the N-CDs could also be applied as fluorescent ink for anti-forgery.

Preparation, characterization, and oral delivery of insulin loaded carboxylated chitosan grafted poly(methyl methacrylate) nanoparticles.

To improve the efficiency of insulin via oral administration, pH-sensitive carboxylated chitosan grafted poly(methyl methacrylate) nanoparticles (CCGN) were prepared. CCGN were characterized by (1)H NMR, dynamic light scattering, zeta potential, and transmission electron microscopy, and the hypoglycemic effect of insulin loaded CCGN via the oral route was evaluated in normal and diabetic rats. CCGN exhibited a homogeneous morphology and a spherical shape with core-shell structure. They were aggregated in simulated gastric fluid while separated in simulated intestinal fluid. Insulin was mainly located in the shell of the CCGN via hydrogen bonding, electrostatic interaction, and Van der Waals force. Insulin release from the CCGN exhibited a pH-sensitive property in that it had a slow release rate at pH 2.0 and a fast release rate at pH 6.8 and 7.4. The pharmacological bioavailability after oral administration of insulin loaded CCGN at a dose of 25 IU/kg was found to be 9.7%. Besides, CCGN showed desirable tissue and blood compatibility. Therefore, the CCGN would be a promising delivery carrier for protein drugs via the oral route.

Biodegradable nanoparticles based on linoleic acid and poly(beta-malic acid) double grafted chitosan derivatives as carriers of anticancer drugs.

Novel chitosan derivatives carrying linoleic acid (LA) as hydrophobic moieties and poly(beta-malic acid) (PMLA) as hydrophilic moieties (LA/PMLA double grafted chitosan, LMC) were synthesized. It self-assembled into nanoparticles of 190-350 nm in water, which carried negative surface charges in physiological pH. The critical aggregation concentration of the LMC deceased with an increase in the LA content. Paclitaxel (PTX) was loaded into the LMC nanoparticles with a high loading efficiency and the maximum loading capacity of 9.9 +/- 0.4%. PTX-LMC nanoparticles exhibited a sustained release within 24 h in pH 7.4 phosphate-buffered saline (PBS), and the release rate was affected by the LA content and PMLA length. Hemolysis and acute toxicity assessment indicated that the LMC nanoparticles were safe drug carriers for i.v. administration. Additionally, PTX-LMC showed significantly potent tumor inhibition efficacy relative to that of TAXOL in S-180 bearing mice. Therefore, the LMC nanoparticles could be an effective and safe vehicle for systemic administration of hydrophobic drugs, especially PTX.

Low density lipoprotein mimic nanoparticles composed of amphipathic hybrid peptides and lipids for tumor-targeted delivery of paclitaxel.

BACKGROUND: Low density lipoprotein (LDL) has been regarded as a promising antitumor drug vehicle. However some problems, such as rare source, difficulty of large-scale production, and potential safety concerns, hinder its clinical application. PURPOSE: The objective of this study is to develop a biomimetic LDL nanocarrier by replacing the native apolipoprotein B-100 (apoB-100) with an artificial amphipathic peptide and demonstrate its antitumor efficacy. METHODS: The amphipathic hybrid peptide (termed as FPL) consisting of a lipid binding motif of apoB-100 (LBMapoB)-polyethylene glycol (PEG)-folic acid (FA) was synthesized and characterized by 1H NMR and circular dichroism. FPL decorated lipoprotein-mimic nanoparticles (termed as FPLM NPs) were prepared by a modified solvent emulsification method. Paclitaxel (PTX) was incorporated into NPs and its content was quantified by HPLC analysis. The morphology of NPs was observed by transmission electron microscopy (TEM), and the particle size and zeta potential of NPs were determined by dynamic light scattering (DLS). The colloidal stability of FPLM NPs was evaluated in PBS containing bovine serum albumin (BSA). In vitro release of PTX loaded FPLM NPs was evaluated using the dialysis method. Cellular uptake and cytotoxity assayswere evaluated on human cervical cancer cells (HeLa) and lung cancer cells (A549). Tumor inhibition in vivo was investigated in M109 tumor-bearing mice via tail vein injection of Taxol formulation and PTX loaded NPs. RESULTS: The composition of FPLM NPs, including cholesteryl oleate, glyceryl trioleate, cholesterol, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and FPL peptides, was optimized to be 5:1:1:3:10 (w/w). FPLM NPs had a spherical shape with a mean diameter of 83 nm and a negative charge (-12 mV). FPLM NPs with optimum formulation had good colloidal stability in BSA solution.The release of PTX from FPLM NPs was slow and sustained. The uptake of FPLM NPs was higher in folate receptor (FR) overexpressing tumor cells (HeLa cells) than in FR deficient tumor cells (A549 cells). The intracellular distribution indicated that FPLM NPs had the lysosome escape capacity. The internalization mechanism of FPLM NPs was involved with clathrin- and caveolae-mediated endocytosis and FR played a positive role in the internalization of FPLM NPs. The CCK-8 assay demonstrated that FPLM NPs exhibited notably better anti-tumor effect than Taxol formulation in vitro. Moreover, PTX loaded FPLM NPs produced very marked anti-tumor efficiency in M109 tumor-bearing mice in vivo. CONCLUSION: FPLM NPs is a promising nanocarrier which can improve the therapeutic effect and reduce the side effects of antitumor drugs.

Brain-targeted delivery of trans-activating transcriptor-conjugated magnetic PLGA/lipid nanoparticles.

Magnetic poly (D,L-lactide-co-glycolide) (PLGA)/lipid nanoparticles (MPLs) were fabricated from PLGA, L-α-phosphatidylethanolamine (DOPE), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-amino (polyethylene glycol) (DSPE-PEG-NH2), and magnetic nanoparticles (NPs), and then conjugated to trans-activating transcriptor (TAT) peptide. The TAT-MPLs were designed to target the brain by magnetic guidance and TAT conjugation. The drugs hesperidin (HES), naringin (NAR), and glutathione (GSH) were encapsulated in MPLs with drug loading capacity (>10%) and drug encapsulation efficiency (>90%). The therapeutic efficacy of the drug-loaded TAT-MPLs in bEnd.3 cells was compared with that of drug-loaded MPLs. The cells accumulated higher levels of TAT-MPLs than MPLs. In addition, the accumulation of QD-loaded fluorescein isothiocyanate (FITC)-labeled TAT-MPLs in bEnd.3 cells was dose and time dependent. Our results show that TAT-conjugated MPLs may function as an effective drug delivery system that crosses the blood brain barrier to the brain.

Experimental antibacterial and mineralizing calcium phosphate-based treatment for dentin surfaces.

OBJECTIVES: This study aimed to determine the efficacy of experimental calcium phosphate-based solutions (sCaP) containing fluoride (F), with and without zinc (Zn) ions on reducing susceptibility to acid dissolution and Streptococcus mutans (S. mutans) colonization of dentin surfaces. METHODS: Dentin sections were treated with double distilled water (control) and with sCaP solutions differing in pH and in F(-) and/or Zn(2+) ion concentrations. Solutions A (pH 7); B, C, and D (pH 5.5); solution C, twice Zn(2+) and F(-) ion concentration compared to B; solution D is similar to C but without Zn(2+). The dentin surfaces were characterized using scanning electron microscopy (SEM), x-ray diffraction, and Fourier Transform Infrared spectroscopy. Dissolution was determined in acidic buffer. Bacterial (S. mutans) attachment and growth were evaluated using SEM and Bioquant. Statistical analyses applied analysis of variance (ANOVA) and Duncan's multiple Range test. RESULTS: Compared to control, dentin surfaces treated with sCaP solutions showed: (a) occluded dentin tubules; (b)reduced susceptibility to acid dissolution; and (c) Zn(2+) ions were more effective than F(-) ions in inhibiting bacterial colonization. SIGNIFICANCE: Acidic sCaP containing both F and Zn ions have mineralizing, acid resistance, and antibacterial effects and may be potentially useful as a strategy against dentin caries formation and progression.

Effect of ZnCl2 on plaque growth and biofilm vitality.

OBJECTIVE: The aim of this study was to evaluate the effects of ZnCl(2) on plaque-growth and vitality pattern of dental biofilm and to determine the optimum zinc concentration for the inhibition of plaque formation. DESIGN: Data were collected from nine volunteers for whom a special-designed acrylic appliance was prescribed after a careful dental check up. The volunteers rinsed twice daily for 2min with ZnCl(2) of 2.5, 5, 10, 20mM as treatment and double distilled water (DDW) as control in respective assigned test weeks. The plaque index (PI) was assessed after 48h of appliance wearing. The glass discs with the adhered biofilm were removed from the splints and stained with two fluorescent dyes. The biofilm thickness (BT) and bacterial vitality of the whole biofilm as well as the mean bacterial vitality (BV) of the inner, middle and outer layers of biofilm were evaluated under confocal laser scanning microscope (CLSM). RESULTS: PI, BT and BV of biofilms treated by various concentrations of ZnCl(2) were reduced significantly when compared with the DDW group (p<0.05). PI, BT and BV of the 2.5mM ZnCl(2) group was significantly higher than groups of 5, 10, 20mM ZnCl(2) (p<0.05). The mean BV of the 3 layers (inner, middle and outer layers) showed that 2.5mM ZnCl(2) was the lowest concentration to inhibit BV in the outer layer, 5mM was the lowest concentration to extend this inhibition of BV to the middle layer, and none of the concentrations investigated in this study has shown any effect on bacteria inhibition in the inner layer. CONCLUSION: Zinc ions exhibited possible inhibitory effects on plaque formation, and have a promising potential to be used as an antibacterial agent in future dentifrices and mouthrinses.

Hyaluronic acid coated poly(butyl cyanoacrylate) nanoparticles as anticancer drug carriers.

The hyaluronic acid (HA) coated poly(butyl cyanoacrylate) (PBCA) nanoparticles were synthesized through radical polymerization of butyl cyanoarylate (BCA) initiated by cerium ions in the presence of HA. The chemical coupling between HA and PBCA was demonstrated by FTIR, (1)H NMR and X-ray diffraction. The sizes of the nanoparticles with different HA/BCA ratios were 291-325 nm at cerium concentration of 0.8 mmol/L and HA molecular weight of 18,000 Da. Paclitaxel (PTX), a model anticancer drug, was encapsulated in negatively charged nanoparticles with a maximal encapsulation efficiency of 90%. In vitro release demonstrated that HA modification could effectively reduce the initial burst release in the first 10h and provide a sustained release in the subsequent 188 h. As evidenced by the hemolysis assay and MTT assay, HA coating could significantly reduce the cytotoxicity. Cellular uptake indicated that uptake of HA-PBCA nanoparticles by Sarcoma-180 (S-180) cells was 9.5-fold higher than that of PBCA nanoparticles. PTX-loaded HA-PBCA nanoparticles were more potent in tumor growth suppression than PTX-loaded PBCA nanoparticles or PTX injection following intravenous administration to S-180 tumor bearing mice. Therefore, the HA-PBCA nanoparticles could be an effective and safe vehicle for systemic administration of hydrophobic anticancer drugs.