Preparation and Characterization of Doxorubicin-Loaded Sterically Stabilized Immunoliposomes

Purpose. To compare the performance of sterically stabilized, doxorubicin-loaded liposomes with and without surface attached specific antibodies (D-SSIL and D-SSL, respectively). Methods. Small ( 120 nm) unilamellar liposomes were prepared composed of hydrogenated soy phosphatidylcholine, hydrogenated phosphatidylethanolamine (HPE), cholesterol, and ²⁰⁰⁰Da polyethylene glycol (²⁰⁰⁰PEG) attached to the primary amino group of distearoyl phosphatidylethanolamine. Doxorubicin was remote-loaded into these liposomes by an ammonium sulfate gradient to form the D-SSL. Monoclonal IgG₃ NI32/2 antibodies directed against a polyoma virus tumor-associated antigen expressed on A9 etc 102 murine fibrosarcoma cells were attached to the D-SSL HPE via a thioether bond to form the D-SSIL-32/2. A control of nonspecific D-SSIL was prepared by attaching nonspecific IgG₃-enriched immunoglobulins to D-SSL. All liposomes were physically and chemically characterized and then tested in vitro for tumor cell binding, specificity, and uptake by macrophages; and in vivo for the drug plasma pharmacokinetics after intravenous administration in mice. Results. (i) The attachment of antibodies to D-SSL did not impair their chemical or physical stability and had a minimal effect on their size and level of loaded drug, (ii) The combination of specific antibodies and ²⁰⁰⁰PEG grafted in the liposomes improved the specific binding to relevant target cells by reducing the level of unspecific binding to nonrelevant cells. (iii) D-SSIL retained the prolonged circulation and slow clearance typical of SSL lacking the antibodies. Conclusions. Sterically stabilized immunoliposomes exhibited stability, ability to recognize target cells, and prolonged circulation time. This study also shows that it is feasible to prepare them in pharmaceutically acceptable dosage form. Thus, further investigation for tumor targeting and efficacy is warranted.     

Convection-enhanced delivery of nanodiamond drug delivery platforms for intracranial tumor treatment

This study examined a novel drug delivery system for treatment of malignant brain gliomas: DOX complexed with nanodiamonds (ND-Dox), and administered via convection-enhanced delivery (CED). Drug retention and toxicity were examined in glioma cell lines, and distribution, retention and toxicity were examined in normal rat parenchyma. Efficacy was assessed in a bioluminescence rodent tumor model. NDs markedly enhanced DOX uptake and retention in glioma cells. ND-Dox delivered via CED extended DOX retention and localized DOX toxicity in normal rodent parenchyma, and was significantly more efficient at killing tumor cells than uncomplexed DOX. Outcomes from this work suggest that CED of ND-Dox is a promising approach for brain tumor treatment.From the Clinical EditorIn this paper, nanodiamonds were utilized to enhance delivery of DOX in a preclinical glioma model using a convection-enhanced delivery method, demonstrating remarkably enhanced efficacy.     

冰片和叶酸共修饰的阿霉素聚酰胺-胺复合物在动物体内的研究

目的 研究用冰片（borneol,BO）和叶酸（folic acid,FA）共修饰阿霉素（doxorubicin,DOX）聚酰胺-胺型树状[poly（amido amine）,PAMAM]大分子（FA-BO-PAMAM/DOX）,增加药物在脑胶质瘤部位递送。方法 第5代PAMAM树状大分子分别与BO和FA通过共价结合得FA-BO-PAMAM。以FA-BO-PAMAM为纳米载体,制备了FA-BO-PAMAM/DOX,通过尾静脉注射该复合物,考察荷瘤大鼠体内的药动学行为及组织分布情况。结果 BO-PAMAM/DOX和FA-BO-PAMAM/DOX组的大鼠血浆半衰期（plasma half-life,t_1/2）和平均滞留时间（mean retention time,MRT）均较原药组显著延长（P<0.01）;血药浓度-时间曲线下面积（area under the plasma concentration-time curve,AUC）较原药组显著增大（P<0.01）。与DOX相比,BO-PAMAM/DOX和FA-BO-PAMAM/DOX在肿瘤组织中的药物含量明显增加,而在心脏中的药物含量明显降低。结论 采用合成的药物载体FA-BO-PAMAM包载DOX后,可显著改变DOX的部分药动学参数,使药物在血浆中能维持较长时间。另外FA-BO-PAMAM/DOX具有较好的肿瘤靶向治疗效果和较小的心脏不良反应,对提高DOX的治疗指数具有较好的临床价值。     

Development,characterization and cancer targeting potential of surface engineered carbon nanotubes

Abstract

The aim of the present study was to assess the in vitro and in vivo potential of doxorubicin-loaded, folic acid appended engineered multi-walled carbon nanotubes (DOX/FA-PEG-MWCNTs) for efficient tumor targeting. The loading efficiency was determined to be 92.0?±?0.92 (DOX/FA-PEG-MWCNTs) in phosphate buffer solution (pH 7.4) ascribed to π–π stacking interaction. The developed nanoconjugates were evaluated for in vitro DOX release, erythrocytes toxicity, ex vivo cytotoxicity and cell uptake studies on MCF-7 (breast cancer cell line). The DOX/FA-PEG-MWCNTs nanoconjugate affords higher efficacy in tumor growth suppression due to its stealth nature and most preferentially taken up by the cultured MCF-7 through caveolae-mediated endocytosis as compared to free DOX. The in vivo studies were performed to determine the pharmacokinetics, biodistribution and antitumor efficacy on tumor bearing female Sprague Dawley rats and improved pharmacokinetics confirm the function of FA-PEG conjugated CNTs. The median survival time for tumor bearing rats treated with DOX/FA-PEG-MWCNTs (30?d) was extended very significantly as compared to free DOX (p?<?0.001). The results concluded that developed water-soluble nano-conjugates might emerge as “safe and effective” nano-medicine in cancer treatment by minimizing the side effects with and Generally Regarded as Safe prominence.     

Antitumor Activity of Folate Receptor-Targeted Liposomal Doxorubicin in a KB Oral Carcinoma Murine Xenograft Model

Purpose. The expression of folate receptor (FR) is amplified in many types of human cancers. Previously, FR-targeted liposomal doxorubicin (f-L-DOX) has been shown to exhibit superior and selective cytotoxicity against FR(+) tumor cells in vitro compared to nontargeted liposomal doxorubicin (L-DOX). This study further investigates f-L-DOX for its antitumor efficacy in vivo using a murine tumor xenograft model. Methods. F-L-DOX composed of DSPC/cholesterol/PEG-DSPE/folate-PEG-DSPE (65:31:3.5:0.5, mole/mole) was prepared by polycarbonate membrane extrusion followed by remote loading of DOX. Athymic mice on a folate-free diet were engrafted with FR(+) KB cells. Two weeks later, these mice were treated with f-L-DOX, L-DOX, or free DOX in a series of six injections (given intraperitoneally on every fourth day at 10 mg/kg DOX) and monitored for tumor growth and animal survival. The plasma clearance profiles of the DOX formulations and the effect of dietary folate on plasma folate concentration were also analyzed. Results. Plasma folate level remained in the physiologic range relative to that in humans. F-L-DOX exhibited an extended systemic circulation time similar to that of L-DOX. Mice that received f-L-DOX showed greater tumor growth inhibition and a 31% higher (p < 0.01) increase in lifespan compared to those that received L-DOX. Meanwhile, free DOX given at the same dose resulted in significant toxicity and was less effective in prolonging animal survival. Conclusions. FR-targeted liposomes are a highly efficacious vehicle for in vivo delivery of anticancer agents and have potential application in the treatment of FR(+) solid tumors.     

Enhanced Intracellular Uptake of Sterically Stabilized Liposomal Doxorubicin <Emphasis Type="Italic">in Vitro</Emphasis> Resulting in Improved Antitumor Activity <Emphasis Type="Italic">in Vivo</Emphasis>

Purpose To investigate the correlation between the in vitro intracellular uptake and the in vivo antitumor activity of anticancer drugs delivered by sterically stabilized liposomes (SSL).Methods Arginine-glycine-aspartic acid (RGD) peptide or RGD mimetic (RGDm) was coupled onto the surface of SSL to obtain the cell-binding carrier to facilitate the intracellular delivery of the encapsulated drugs. DOX-loaded SSL (SSL-DOX), DOX-loaded RGD-modified SSL (RGD-SSL-DOX) and DOX-loaded RGDm-modified SSL (RGDm-SSL-DOX) were prepared by lipid film dispersion followed by remote loading of DOX. The intracellular uptake of DOX from the various liposomal formulations was evaluated in vitro with melanoma B16 cells, and the pharmacokinetics, biodistribution, and antitumor activity were compared in C57BL/6 mice carrying melanoma B16 tumors.Results In vitro intracellular uptake of DOX by B16 cells and in vivo antitumor activity in terms of tumor growth inhibition and mice survival time prolongation for various liposomal DOX were in the following order: RGD-SSL-DOX > RGDm-SSL-DOX > SSL-DOX. The mean survival time of the mice treated with RGD-SSL-DOX, RGDm-SSL-DOX, and SSL-DOX was 55, 49, and 44 days, respectively. The three liposomal DOX formulations produced very close DOX accumulation in tumor, which is significantly higher than that of free DOX. RGD- or RGDm-SSL-DOX demonstrated prolonged circulation time similar to that of SSL-DOX, whereas they showed significantly lower DOX level in blood and remarkably higher uptake by spleen than SSL-DOX.Conclusions Enhanced intracellular uptake of DOX encapsulated in SSL could produce an improved therapeutic effect for the melanoma B16 tumors. Enhancing intracellular delivery of the anticancer drugs encapsulated in SSL may be a promising strategy to improve their therapeutic efficacy for solid tumors.     

Human MCAF Gene Transfer Enhances the Metastatic Capacity of a Mouse Cachectic Adenocarcinoma Cell Line in Vivo

Purpose. To evaluate the effect of monocyte chemotactic and activating factor (MCAF/MCP-1/JE) on tumor progression and metastasis. Methods. Cachexia-inducing adenocarcinoma cells (cell line colon 26, clone 20) were transfected with either a control plasmid or MCAF expression vector. Spontaneous lung metastases were determined in mouse. Results. The production of MCAF reached 0.4 ng/ml in vitro when transfectant cells were cultured at a cell density of 5 × 10⁴ cells/ml for 3 days. Transfection of MCAF expression vector did not affect the growth rate in vitro. Also, after MCAF-transfection, the size of tumors after intra-footpad inoculation was similar to that of the parental cells. When the primary tumors were resected on the 10th day after inoculation, the incidence of spontaneous lung metastasis was less than 20% in both cells. The number of endothelial cells in the primary tumor rapidly increased from the 10th to the 14th day after inoculation, as revealed by immunohistochemical staining. In accordance with enhanced angiogenesis, the incidence rates of spontaneous metastasis increased when the primary tumors were resected on the 14th day after inoculation. Moreover, the spontaneous lung metastases were augmented in the animals injected with MCAF-transfectants compared to those injected with parental cells with a concomitant increase of angiogenesis. Conclusions. These results suggest that MCAF may augment the metastatic potential by modulating tumor associated angiogenesis.     

Development of biodegradable polymeric implants of RGD-modified PEG-PAMAM-DOX conjugates for long-term intratumoral release

Abstract

Context: The sustained release implants can be directly implanted in tumor site by surgery and are promising for cancer treatment.

Objective: RGD-modified PEGylated polyamidoamine (PAMAM) dendrimer with doxorubicin (DOX) conjugated by acid-sensitive linkage (RGD-PPCD) was a potential conjugate for tumor-targeted therapy. In order to enhance tumor retention ability and long-term effect of drug, we developed the DOX and its conjugate implants using poly(dl-lactic-co-glycolic acid) (PLGA), poly(dl-lactic acid) (PLA) and polyethylene glycol (PEG) as carrier materials.

Methods: The implants were prepared by a simple solvent evaporation method. Different formulations with varying ratios of three polymers were designed, prepared and evaluated on the basis of viscosity, in vitro release and drying time. Furthermore, in vivo biodistribution and antitumor activity of the implants were studied in mice with subcutaneous C6 xenografts.

Results: The optimized formulation was obtained with the 3:1 ratio of PLGA/PLA (w/w) and 1% PEG (wt.%). The drug release behavior of DOX, PPCD and RGD-PPCD implants prepared by the optimized formulation was similar according to the assessment of similarity factor f₂, and the release curves were fell into three phases, including a lag-period, then the second phase which was consistent with zero-order model followed by a plateau. Data of total DOX remained in implants indicated the release were faster in vivo than in vitro. Moreover, intratumoral drug amount of RGD-PPCD implants was the highest 45 days after implantation. Correspondingly, the RGD-PPCD implants exhibited the strongest antitumor activity compared with PPCD and free DOX implants.

Discussion and conclusion: This paper presents an exploratory research on macromolecule-drug conjugates, including RGD-PPCD and PPCD, which have the potential to be developed into long-term effect implants for tumor therapy with high efficiency and low systematic toxicity.     

Intratracheal <Emphasis Type="BoldItalic">Versus</Emphasis> Intravenous Liposomal Delivery of siRNA,Antisense Oligonucleotides and Anticancer Drug

Purpose  To compare systemic intravenous and local intratracheal delivery of doxorubicin (DOX), antisense oligonucleotides (ASO) and small interfering RNA (siRNA). Methods  “Neutral” and cationic liposomes were used to deliver DOX, ASO, and siRNA. Liposomes were characterized by dynamic light scattering, zeta-potential, and atomic force microscopy. Cellular internalization of DOX, ASO and siRNA was studied by confocal microscopy on human lung carcinoma cells. In vivo experiments were carried out on nude mice with an orthotopic model of human lung cancer. Results  Liposomes provided for an efficient intracellular delivery of DOX, ASO, and siRNA in vitro. Intratracheal delivery of both types of liposomes in vivo led to higher peak concentrations and much longer retention of liposomes, DOX, ASO and siRNA in the lungs when compared with systemic administration. It was found that local intratracheal treatment of lung cancer with liposomal DOX was more efficient when compared with free and liposomal DOX delivered intravenously. Conclusions  The present study outlined the clear advantages of local intratracheal delivery of liposomal drugs for the treatment of lung cancer when compared with systemic administration of the same drug.     

The Influence of Cytotoxicity of Macromolecules and of VEGF Gene Modulated Vascular Permeability on the Enhanced Permeability and Retention Effect in Resistant Solid Tumors

Purpose. To study the influence of cytotoxicity of macromolecules,VEGF gene expression, and vascular permeability on the enhancedpermeability and retention (EPR) effect. Methods. Mice bearing xenografts of A2780 multidrug resistant humanovarian carcinoma were treated by free doxorubicin (DOX) andN-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-bound DOX(P(GFLG)-DOX), Texas Red (P-TR), and FITC (P-FITC). Antitumoractivity, drug distribution in tumor, vascular permeability, VEGF geneexpression, and DNA fragmentation were studied. Results. The accumulation of free DOX led to the VEGF geneoverexpression and increased the vascular permeability, which in turnenhanced the drug accumulation in the same location. This positivefeedback loop led to a highly inhomogeneous distribution of the drugwithin the tumor. In contrast, P(GFLG)-DOX down-regulated theVEGF gene and decreased vascular permeability. This negativefeedback seemed to prevent additional drug accumulation in dead necrotictissue, resulting in a more uniform drug distribution and enhanced theantitumor activity P(GFLG)-DOX. Conclusions. The EPR effect significantly differed for macromoleculescontaining DOX when compared to macromolecules without drug. Thecytotoxicity of P(GFLG)-DOX amplified the EPR effect, led to amore homogenous distribution of the drug, increased the average drugconcentration in tumor and augmented its efficacy.     

Anti-cancer activity of anti-GLUT1 antibody-targeted polymeric micelles co-loaded with curcumin and doxorubicin

Abstract

Background: Treatment of late stage cancers has proven to be a very difficult task. Targeted therapy and combinatory drug administration may be the solution.

Purpose: The study was performed to evaluate the therapeutic efficacy of PEG-PE micelles, co-loaded with curcumin (CUR) and doxorubicin (DOX), and targeted with anti-GLUT1 antibody (GLUT1) against HCT-116 human colorectal adenocarcinoma cells both in vitro and in vivo.

Methods: HCT-116 cells were treated with non-targeted and GLUT1-targeted CUR and DOX micelles as a single agent or in combination. Cells were inoculated in female nude mice. Established tumors were treated with the micellar formulations at a dose of 4?mg/kg CUR and 0.4?mg/kg DOX every 2?d for a total of 7 injections.

Results: CUR?+?DOX-loaded micelles decorated with GLUT1 had a robust killing effect even at low doses of DOX in vitro. At the doses chosen, non-targeted CUR and CUR?+?DOX micelles did not exhibit any significant tumor inhibition versus control. However, GLUT1-CUR and GLUT1-CUR?+?DOX micelles showed a significant tumor inhibition effect with an improvement in survival.

Conclusion: We showed a dramatic improvement in efficacy between the non-targeted and GLUT1-targeted formulations both in vitro and in vivo. Hence, we confirmed that GLUT1-CUR?+?DOX micelles are effective and deserve further investigation.     

Polymeric Drug-Carriers Containing Doxorubicin and Melanocyte-Stimulating Hormone: In Vitro and In Vivo Evaluation Against Murine Melanoma

Abstract

N-(2-Hydroxypropyl)methacrylamide (HPMA) copolymers containing doxorubicin (DOX, approximately 8% by weight) bound via the lysosomally degradable spacer Gly-Phe-Leu-Gly and, in certain cases, also melanocyre-stimulating hormone (MSH, 5-10% by weight) were synthesized with the aim of developing a drug conjugate for site-specific delivery to malignant melanoma. Polymer-bound MSH, like free MSH, was able to stimulate tyrosinase activity in B16F10 cells in vitro, confirming the ability of conjugated hormone to interact with the MSH receptor. Similarly, a ¹²⁵I-labelled conjugate containing MSH was captured by B16F10 cells in vitro more rapidly than a similar polymer without the targeting moiety. HPMA copolymers containing DOX bound via the lysosomally degradable Gly-Phe-Leu-Gly linkage were cytotoxic to a mouse melanoma cell line (M3 S91) in vitro, the MSH-containing conjugate being more active than that without (although the difference in the ID₅₀ was not significant). When administered intraperitoneally or intravenously to C57BL/6J mice bearing intraperitoneal B16F10 tumours, HPMA copolymers containing DOX linked via this biodegradable spacer (with or without MSH) significantly increased animal survival, the maximum ratio of the mean survival of the test group (T) to that of the untreated control (C) T/C observed (approximately 200) over the dose range 5-20 mg DOX/kg being similar to that seen for free DOX. In contrast, neither polymer conjugates containing DOX bound via a non-degradable linkage (Gly-Gly) nor free MSH showed antitumour activity. In mice bearing established subcutaneous B16F10 tumours, biodegradable polymer-bound DOX conjugates given intraperitoneally were more effective than free DOX (which was virtually inactive in this system); conjugates containing MSH were significantly more effective than those without, the maximum T/C being approximately 148 and 324 respectively. Preliminary pharmacokinetic experiments showed evidence of selective MSH targeting of polymer conjugates to subcutaneous B16F10.     

Folate-decorated poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) nanoparticles for targeting delivery: optimization and in vivo antitumor activity

Abstract

Context: Doxorubicin (DOX)-loaded folate-targeted poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) [P(HB-HO)] nanoparticles [DOX/FA-PEG-P(HB-HO) NPs] have potential application in clinical treatments for cervical cancer due to specific affinity of folate and folate receptor in HeLa cells.

Objective: The aim of this study was to develop an optimized formulation for DOX/FA-PEG-P(HB-HO) NPs, and investigate the targeting and efficacies of the nanoparticles.

Materials and methods: DOX/FA-PEG-P(HB-HO) NPs were prepared by W₁/O/W₂ solvent extraction/evaporation method, and an orthogonal experimental design [L₉ (3⁴)] was applied to establish the optimum conditions. The physico–chemical characteristics, microscopic observation and in vivo antitumor study of the nanoparticles were evaluated.

Results: The optimum formulation was obtained with DOX 10% (w/v), FA-PEG-P(HB-HO) 6.5% (w/v), PVA 3%(w/v) and oil phase/internal water phase volume ratio of 3/1. The size distribution, drug loading and encapsulation efficiency of the optimized nanoparticles were 150–350?nm, 29.6?±?2.9% and 83.5?±?5.7%, respectively. In vitro release study demonstrated that 80% of the drug could release from the nanoparticles within 11 days. Furthermore, in vitro microscopic observation and in vivo antitumor study showed that DOX/FA-PEG-P(HB-HO) NPs could inhibit HeLa cells effectively, and the tumor inhibition rate (TIR) in vivo was 76.91%.

Discussion and conclusions: DOX/FA-PEG-P(HB-HO) NPs have been successfully developed and optimized. In vitro drug release study suggested a sustained release profile. Moreover, DOX/FA-PEG-P(HB-HO) NPs could effectively inhibit HeLa cells with satisfying targeting, and reduce side effects and toxicity to normal tissues. DOX/FA-PEG-P(HB-HO) NPs were superior in terms of inhibiting HeLa tumor over non-targeted formulations therapy.     

Glucosamine-anchored doxorubicin-loaded targeted nano-niosomes: pharmacokinetic,toxicity and pharmacodynamic evaluation

Background: Efficacy of anticancer drug is limited due to non-selectivity and toxicities allied with the drug; therefore the heart of the present work is to formulate drug delivery systems targeted selectively towards cancer cells with minimal toxicity to normal cells.

Purpose: Targeted drug delivery system of doxorubicin (DOX)-loaded niosomes using synthesized N-lauryl glucosamine (NLG) as a targeting ligand.

Methods: NLG-anchored DOX niosomes were developed using ethanol injection method.

Results: Developed niosomes had particle size <150?nm and high entrapment efficiency ～90%. In vivo pharmacokinetics exhibited long circulating nature of targeted niosomes with improved bioavailability, which significantly reduced CL and Vd than DOX solution and non-targeted niosomes (35 fold and 2.5 fold, respectively). Tissue-distribution study and enzymatic assays revealed higher concentration of DOX solution in heart while no toxicity to major organs with developed targeted niosomes was observed. Solid skin melanoma tumor model in mice manifested the commendable targeting potential of targeted niosomes with significant reduction in tumor volume and high % survival rate without drop in body weight in comparison with DOX solution and non-targeted niosomes of DOX.

Conclusion: The glucosamine-anchored DOX-loaded targeted niosomes showed its potential in cancer targeted drug therapy with reduced toxicity. Abbreviations ALT alanine transaminase

CL clearance

CPK creatinine phosphokinase

DOX doxorubicin

EDC.HCL ethyl carbidimide hydrochloride

GLUT glucose transporter

GSH glutathione S-transferase

LDH lactate dehydrogenase

LHRH luteinizing hormone-releasing hormone

MDA malonaldehyde

NHS N-hydroxy succinimide

NLG N-lauryl glucosamine

NTAR DoxNio non-targeted doxorubicin niosomes

PBS phosphate buffer saline

RGD argynyl glycyl aspartic acid

SGOT serum glutamate oxaloacetate transaminase

SGPT serum glutamate pyruvate transaminase

SOD superoxide dismutase

TAR DoxNio targeted doxorubicin niosomes

Vd volume of distribution

     

Which one performs better for targeted lung cancer combination therapy: pre- or post-bombesin-decorated nanostructured lipid carriers?

Abstract

Purpose: The co-delivery of gene and drugs has the potential to treat cancer. The aim of this study was to compare post-bombesin decorated nanostructured lipid carriers (NLC) carrying both doxorubicin (DOX) and DNA with pre-bombesin decorated NLC for lung cancer therapy.

Methods: Post-bombesin decorated NLC were prepared by two steps. First, DOX and DNA-loaded NLC (DOX-DNA-NLC) was prepared. Second, Bombesin-NH₂ (BN-NH₂) was added into DOX-DNA-NLC to react with stearic acid-polyethylene glycol-COOH (SA-PEG-COOH) loaded in NLC. Pre-bombesin decorated NLC were prepared by two steps. First, Bombesin (BN)-conjugated ligands were synthesized. Second, DOX and DNA were loaded into BN decorated NLC. Their average size, zeta potential, drug and gene loading were evaluated. NCl-H460 human non-small lung cancer cells (NCl-H460 cells) were used for the testing of in vitro transfection efficiency and in vitro cytotoxicity. In vivo transfection efficiency and anti-tumor effect of NLC were evaluated on mice bearing NCl-H460 cells model.

Results: Post-bombesin decorated NLC has a particle size of 128?nm, DOX encapsulation efficiency (EE) of 85% and DNA EE of 91%. Pre-bombesin decorated NLC has a particle size of 101?nm, DOX EE of 86% and DNA EE of 92%. Post-bombesin decorated NLC displayed more stable and remarkably higher transfection efficiency and better anti-tumor ability than pre-bombesin decorated NLC both in vitro and in vivo.

Conclusion: Post-bombesin decorated NLC could function as better carriers to improve the cell targeting and nuclear targeting ability. The resulting nanomedicine could be a promising active targeting drug/gene therapeutic system for lung cancer therapy.     

负载阿霉素的黄芩苷纳米粒的制备及其体外性能评价

目的 制备负载阿霉素的黄芩苷纳米粒（DOX/SA-SS-BAI NPs）,并评价其体外性能。方法 构建以胱胺为连接臂的海藻酸钠–黄芩苷聚合物,并负载阿霉素,得到DOX/SA-SS-BAI NPs。对DOX/SA-SS-BAI NPs的理化性质进行表征;采用HepG2细胞进行MTT实验验证其细胞毒性。结果 DOX/SA-SS-BAI NPs粒径为（158.2±2.8）nm,PDI为（0.241±0.008）,Zeta电位为（−24.1±0.3）mV,包封率为（64.34±0.25）%,载药量为（16.22±0.06）%。体外释放显示载药纳米粒具有良好的还原响应性;MTT实验证明DOX/SA-SS-BAI NPs对HepG2细胞具有良好的抑制作用;细胞摄取实验表明DOX/SA-SS-BAI NPs在HepG2细胞内较快地释放阿霉素。结论 制备的DOX/SA-SS-BAI NPs具有较好的理化性质和体外抗癌作用。     

Comparative in vitro activity of 4′-deoxy-4′-iododoxorubicin and other anthracyclines in the human tumor clonogenic assay

A new halogenated anthracycline analog 4-deoxy-4-iododoxorubicin (IODO) was compared with doxorubicin (DOX) and deoxydoxorubicin (DEOX) in the human tumor clonogenic assay (HTCA) using human tumor cell lines. For all cell lines tested, IODO had lower ID₅₀ value and thus greater in vitro potency and cytotoxicity than DOX. DEOX had lower average ID₅₀ values than either IODO or DOX in all cell lines except HEC1A, where DEOX was equal to IODO. Analysis of variance likewise confirmed significantly greater activity for IODO versus DOX in most cell lines tested. Previous in vivo studies demonstrate oral activity in a variety of tumors as well as less cardiotoxicity. Thus, the results of in vitro and in vivo studies suggest that IODO is an active compound of potential clinical interest.     

Chitooligosaccharides Modified Reduction-Sensitive Liposomes: Enhanced Cytoplasmic Drug Delivery and Osteosarcomas-Tumor Inhibition in Animal Models

Purpose

To investigate the potential of a reduction-sensitive and fusogenic liposomes, enabled by surface-coating with chotooligosaccharides (COS) via a disulfide linker, for tumor-targeted cytoplasmic drug delivery.

Methods

COS (MW2000-5000) were chemically tethered onto the liposomes through a disulfide linker (-SS-) to cholesterol (Chol). Doxorubicin (DOX) was actively loaded in the liposomes. Their reduction-sensitivities, cellular uptake, cytotoxicity, pharmacokinetics and antitumor efficacy were investigated.

Results

The Chol-SS-COS/DOX liposomes (100 nm) had zeta potential of 33.9 mV and high drug loading (13% w/w). The liposomes were stable with minimal drug leakage under physiological conditions but destabilized in the presence of reducing agents, dithiothreitol (DTT) or glutathione (GSH) at 10 mM, the cytosolic level. MTT assay revealed that the cationic Chol-SS-COS/DOX liposomes had higher cytotoxicity to MG63-osteosarcoma cells than non-reduction sensitive liposome (Chol-COS/DOX). Flow cytometry and confocal microscopy revealed that Chol-SS-COS/DOX internalized more efficiently than Chol-COS/DOX with more content to cytoplasm whereas Chol-COS/DOX located around the cell membrane. Chol-SS-COS/DOX preferentially internalized into MG63 cancer cell over LO2 normal liver cells. In rats both liposomes produced a prolonged half-life of DOX by 4 - 5.5 fold (p < 0.001) compared with the DOX solution. Chol-SS-COS/DOX exhibited strong inhibitory effect on tumor growth in MG63 cell-bearing nude mice (n = 6), and extended animal survival rate.

Conclusions

Reduction-responsive Chol-SS-COS liposomes may be an excellent platform for cytoplasmic delivery of anticancer drugs. Conjugation of liposomes with COS enhanced tumor cell uptake, antitumor effect and survival rate in animal models.

     

Liquid Dose Pulmonary Instillation of Gentamicin PulmoSpheres® Formulations: Tissue Distribution and Pharmacokinetics in Rabbits

Purpose. To assess the pharmacokinetics and biodistribution of gentamicin, delivered as PulmoSpheres® formulations in rabbit serum and lung tissue following intratracheal instillation in a perflubron vehicle. Methods. Rabbits were anesthetized, intubated, and mechanically ventilated with O₂(FiO₂ = 0.50). Animals were then given 5 mg/kg gentamicin either intravenously, intramuscularly (IM), or intratracheally (IT) gentamicin PulmoSpheres® formulation, instilled in 1.8 ml/kg of liquid perflubron vehicle. Serum and lung lobe sections were collected at multiple time points and assayed for gentamicin content. Results. Serum gentamicin levels peaked at 64.7 g/ml, 11.2 g/ml, and 5.0 g/ml following intravenous, IM, and IT administration, respectively. Absolute bioavailability at 8 h for IM administration was 76.8% and 57.0% when delivered IT. Although peak lung levels of drug were reached within 1 h, total lung gentamicin concentration after IT administration was more than two orders of magnitude greater than that achieved following IM administration (680,540 vs. 4,985 g min, respectively) with significant levels of the antibiotic remaining in the lung even after 1 week. Conclusions. High levels of gentamicin in lung tissue can be achieved by instillation of a gentamicin PulmoSpheres® formulation in a perflubron vehicle, termed liquid dose installation, without reaching toxic systemic levels allowing for increased local delivery of agents such as gentamicin at the site of the infection.     

Single-walled carbon nanotube-loaded doxorubicin and Gd-DTPA for targeted drug delivery and magnetic resonance imaging

An aspargine-glycine-arginine (NGR) peptide modified single-walled carbon nanotubes (SWCNTs) system, developed by a simple non-covalent approach, could be loaded with the anticancer drug doxorubicin (DOX) and magnetic resonance imaging (MRI) contrast agent gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). This DOX- and Gd-DTPA-loaded NGR functionalized SWCNTs (DOX/NGR-SWCNTs/Gd-DPTA) retained both cytotoxicity of DOX and MRI contrast effect of Gd-DPTA. This drug delivery system showed excellent stability in physiological solutions. This DOX/NGR-SWCNTs/Gd-DPTA system could accumulate in tumors and enter into tumor cells, which facilitated combination chemotherapy with diagnosis of tumor in one system. An excellent in vitro anti-tumor effect was shown in MCF-7 cells treated by DOX/NGR-SWCNTs/Gd-DPTA, compared with DOX solution, DOX/SWCNTs and DOX/SWCNTs/Gd-DPTA. In vivo data of DOX/NGR-SWCNTs/Gd-DPTA group in tumor-bearing mice further confirmed that this system performed much higher tumor targeting capacity and anti-tumor efficacy than other control groups.