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1.
J Control Release ; 318: 145-157, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31830540

RESUMO

Quantum dots offer superior optical features and hold a great potential as an imaging tool in comparison to 'conventional' fluorescent dyes. However, in vivo application in inflammatory-associated disorders is limited due to potential toxicity following systemic administration. Vascular inflammation contributes to cardiovascular diseases such as restenosis (re-narrowing of the artery following angioplasty), and poor prognosis is associated with the increased number of monocytes-derived macrophages (MDMs) in the arterial wall. Local administration of a suitable delivery system targeting MDMs could provide effective fluorescent imaging while minimizing systemic exposure and toxicity. We report here on the physicochemical characteristics and the structural stability of MDMs-targeted liposomal QDs (LipQDs), cellular uptake and cytotoxicity, the systemic biodistribution of LipQDs following local intra-luminal administration of LipQDs in carotid-injured rats vs. systemic administration, and imaging of QDs in the arterial tissue. The local treatment with LipQDs was found to be a suitable approach for targeting QDs to MDMs in the injured artery. In contrast to free QDs, the LipQDs formulation exhibited unique properties including structural and fluorescent stability, increased accumulation and retention for up to 24 h, and targeting properties enabling imaging of MDMs. MDMs imaging by targeted nanoparticles (NPs) could potentially serve for the detection of MDMs density in the injured artery for diagnostic purposes.

2.
Nano Lett ; 19(9): 5844-5852, 2019 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-31424944

RESUMO

The majority of developed and approved anticancer nanomedicines have been designed to exploit the dogma of the enhanced permeability and retention (EPR) effect, which is based on the leakiness of the tumor's blood vessels accompanied by impeded lymphatic drainage. However, the EPR effect has been under scrutiny recently because of its variable manifestation across tumor types and animal species and its poor translation to human cancer therapy. To facilitate the EPR effect, systemically injected NPs should overcome the obstacle of rapid recognition and elimination by the mononuclear phagocyte system (MPS). We hypothesized that circulating monocytes, major cells of the MPS that infiltrate the tumor, may serve as an alternative method for achieving increased tumor accumulation of NPs, independent of the EPR effect. We describe here the accumulation of liposomal quantum dots (LipQDs) designed for active delivery via monocytes, in comparison to LipQDs designed for passive delivery (via the EPR effect), following IV administration in a mammary carcinoma model. Hydrophilic QDs were synthesized and entrapped in functionalized liposomes, conferring passive ("stealth" NPs; PEGylated, neutral charge) and active (monocyte-mediated delivery; positively charged) properties by differing in their lipid composition, membrane PEGylation, and charge (positively, negatively, and neutrally charged). The various physicochemical parameters affecting the entrapment yield and optical stability were examined in vitro and in vivo. Biodistribution in the blood, various organs, and in the tumor was determined by the fluorescence intensity and Cd analyses. Following the treatment of animals (intact and mammary-carcinoma-bearing mice) with disparate formulations of LipQDs (differing by their lipid composition, neutrally and positively charged surfaces, and hydrophilic membrane), we demonstrate comparable tumor uptake of QDs delivered by the passive and the active routes (mainly by Ly-6Chi monocytes). Our findings suggest that entrapping QDs in nanosized liposomal formulations, prepared by a new facile method, imparts superior structural and optical stability and a suitable biodistribution profile leading to increased tumor uptake of fluorescently stable QDs.


Assuntos
Lipossomos/farmacologia , Neoplasias Mamárias Animais/tratamento farmacológico , Sistema Fagocitário Mononuclear/química , Pontos Quânticos/química , Animais , Vasos Sanguíneos/efeitos dos fármacos , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos , Feminino , Humanos , Interações Hidrofóbicas e Hidrofílicas/efeitos dos fármacos , Lipídeos/química , Lipídeos/farmacologia , Lipossomos/química , Neoplasias Mamárias Animais/patologia , Camundongos , Nanomedicina , Células Neoplásicas Circulantes , Permeabilidade/efeitos dos fármacos
3.
Cancers (Basel) ; 11(4)2019 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-30934857

RESUMO

Non-viral, polymeric-based, siRNA nanoparticles (NPs) have been proposed as promising gene delivery systems. Encapsulating siRNA in targeted NPs could confer improved biological stability, extended half-life, enhanced permeability, effective tumor accumulation, and therapy. In this work, a peptide derived from apolipoprotein B100 (ApoB-P), the protein moiety of low-density lipoprotein, was used to target siRNA-loaded PEGylated NPs to the extracellular matrix/proteoglycans (ECM/PGs) of a mammary carcinoma tumor. siRNA against osteopontin (siOPN), a protein involved in breast cancer development and progression, was encapsulated into PEGylated poly(d,l-lactic-co-glycolic acid) (PLGA) NPs using the double emulsion solvent diffusion technique. The NPs obtained possessed desired physicochemical properties including ~200 nm size, a neutral surface charge, and high siOPN loading of ~5 µg/mg. ApoB-P-targeted NPs exhibited both enhanced binding to isolated ECM and internalization by MDA-MB-231 human mammary carcinoma cells, in comparison to non-targeted NPs. Increased accumulation of the targeted NPs was achieved in the primary mammary tumor of mice xenografted with MDA-MB-231 mammary carcinoma cells as well as in the lungs, one of the main sites affected by metastases. siOPN NPs treatment resulted in significant inhibition of tumor growth (similar bioactivity of both formulations), accompanied with significant reduction of OPN mRNA levels (~40% knockdown of mRNA levels). We demonstrated that targeted NPs possessed enhanced tumor accumulation with increased therapeutic potential in mice models of mammary carcinoma.

5.
Drug Deliv Transl Res ; 8(4): 868-882, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29058205

RESUMO

Major advances have been achieved in understanding the mechanisms and risk factors leading to cardiovascular disorders and consequently developing new therapies. A strong inflammatory response occurs with a substantial recruitment of innate immunity cells in atherosclerosis, myocardial infarction, and restenosis. Monocytes and macrophages are key players in the healing process that ensues following injury. In the inflamed arterial wall, monocytes, and monocyte-derived macrophages have specific functions in the initiation and resolution of inflammation, principally through phagocytosis, and the release of inflammatory cytokines and reactive oxygen species. In this review, we will focus on delivery systems, mainly nanoparticles, for modulating circulating monocytes/monocyte-derived macrophages. We review the different strategies of depletion or modulation of circulating monocytes and monocyte subtypes, using polymeric nanoparticles and liposomes for the therapy of myocardial infarction and restenosis. We will further discuss the strategies of exploiting circulating monocytes for biological targeting of nanocarrier-based drug delivery systems for therapeutic and diagnostic applications.


Assuntos
Doenças Cardiovasculares/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Monócitos/imunologia , Animais , Doenças Cardiovasculares/imunologia , Humanos
6.
Drug Deliv Transl Res ; 8(4): 945-953, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28656488

RESUMO

The innate immunity system plays a critical role in vascular repair and restenosis development. Liposomes encapsulating bisphosphonates (LipBPs), but not free BPs, suppress neointima formation following vascular injury mediated in part by monocytes. The objective of this study was to elucidate the role of monocyte subpopulations on vascular healing following LipBP treatment. The potency- and dose-dependent treatment effect of clodronate (CLOD) and alendronate (ALN) liposomes on restenosis inhibition, total monocyte depletion, and monocytes subpopulation was studied. Rats subjected to carotid injury were treated by a single IV injection of LipBPs at the time of injury. Low- and high-dose LipALN treatment (3 and 10 mg/kg, respectively) resulted in a dose-dependent effect on restenosis development after 30 days. Both doses of LipALN resulted in a dose-dependent inhibition of restenosis, but only high dose of LipALN depleted monocytes (-60.1 ± 4.4%, 48 h post injury). Although LipCLOD treatment (at an equivalent potency to 3 mg/kg alendronate) significantly reduced monocyte levels (72.1 ± 6%), no restenosis inhibition was observed. The major finding of this study is the correlation found between monocyte subclasses and restenosis inhibition. Non-classical monocyte (NCM) levels were found higher in LipALN-treated rats, but lower in LipCLOD-treated rats, 24 h after injury and treatment. We suggest that the inhibition of circulating monocyte subpopulations is the predominant mechanism by which LipBPs prevent restenosis. The effect of LipBP treatment on the monocyte subpopulation correlates with the dose and potency of LipBPs.


Assuntos
Alendronato/administração & dosagem , Lesões das Artérias Carótidas/tratamento farmacológico , Ácido Clodrônico/administração & dosagem , Reestenose Coronária/prevenção & controle , Monócitos/imunologia , Lesões do Sistema Vascular/tratamento farmacológico , Animais , Lesões das Artérias Carótidas/imunologia , Lipossomos , Masculino , Ratos , Lesões do Sistema Vascular/imunologia
7.
Biomaterials ; 145: 154-167, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28863309

RESUMO

siRNA-loaded nanoparticles (NPs) administered systemically can overcome the poor stability and rapid elimination of free double-stranded RNA in circulation, resulting in increased tumor accumulation and efficacy. siRNA against osteopontin (siOPN), a protein involved in breast cancer development, was encapsulated in poly(D,L-lactic-co-glycolic acid) NPs by a double emulsion solvent diffusion (DESD) technique. We also compared the effect of polyethylenimine (PEI) molecular weight (800 Da and 25 kDa), used as the counter-ion for siRNA complexation, on the physicochemical properties of the NPs, cytotoxicity, and cellular uptake. NPs prepared by the DESD technique were obtained at the desired size (∼170 nm) using both types of PEIs, and were characterized with a neutral surface charge, high encapsulation yield (up to ∼60%), siOPN concentration of 5.6-8.4 µg/mg, stability in physiologic conditions in vitro and in vivo, and long-term shelf-life stability (> 3 years). The NPs prepared using both PEIs exhibited no cytotoxicity in primary smooth muscle culture, and no detrimental effect on mice liver enzymes following their IV administration. Following cellular uptake and biodistribution studies, the therapeutic potential of the NPs was demonstrated by a significant decrease of tumor progression and size in an ectopic xenograft model of mammary carcinoma in mice.


Assuntos
Emulsões/química , Ácido Láctico/química , Neoplasias Mamárias Experimentais/terapia , Nanopartículas/química , Ácido Poliglicólico/química , RNA Interferente Pequeno/metabolismo , RNA Interferente Pequeno/toxicidade , Solventes/química , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Difusão , Modelos Animais de Doenças , Endocitose/efeitos dos fármacos , Feminino , Técnicas de Silenciamento de Genes , Inativação Gênica/efeitos dos fármacos , Humanos , Camundongos Endogâmicos BALB C , Peso Molecular , Nanopartículas/ultraestrutura , Osteopontina/metabolismo , Tamanho da Partícula , Polietilenoimina/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Soro , Eletricidade Estática , Distribuição Tecidual/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
8.
J Control Release ; 261: 138-146, 2017 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-28666727

RESUMO

Even though some progress in diagnosis and treatment has been made over the years, there is still no definitive treatment available for Glioblastoma multiforme (GBM). Convection-enhanced delivery (CED), a continuous infusion-mediated pressure gradient via intracranial catheters, studied in clinical trials, enables in situ drug concentrations several orders of magnitude greater than those achieved by systemic administration. We hypothesized that the currently limited efficacy of CED could be enhanced by a liposomal formulation, thus achieving enhanced drug localization to the tumor site with minimal toxicity. We hereby describe a novel approach for treating GBM by CED of liposomes containing the known chemotherapeutic agent, temozolomide (TMZ). A new technique for encapsulating TMZ in hydrophilic (PEGylated) liposomes, characterized by nano-size (121nm), low polydispersity index (<0.13) and with near-neutral charge (-ʒ,0.2mV), has been developed. Co-infusion of PEGylated Gd-DTPA liposomes and TMZ-liposomes by CED in GBM bearing rats, resulted in enhanced tumor detection with longer residence time than free Gd-DTPA. Treatment of GBM-bearing rats with either TMZ solution or TMZ-liposomes resulted in greater tumor inhibition and significantly higher survival. However, the longer survival and smaller tumor volumes exhibited by TMZ liposomal treatment in comparison to TMZ in solution were insignificant (p<0.053); and only significantly lower edema volumes were observed. Thus, there are no clear-cut advantages to use a liposomal delivery system of TMZ via CED over a drug solution.


Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Dacarbazina/análogos & derivados , Sistemas de Liberação de Medicamentos , Glioblastoma/tratamento farmacológico , Animais , Antineoplásicos Alquilantes/administração & dosagem , Antineoplásicos Alquilantes/farmacocinética , Antineoplásicos Alquilantes/farmacologia , Convecção , Dacarbazina/administração & dosagem , Dacarbazina/farmacocinética , Dacarbazina/farmacologia , Gadolínio DTPA/administração & dosagem , Lipossomos , Masculino , Nanopartículas , Tamanho da Partícula , Polietilenoglicóis/química , Ratos , Ratos Endogâmicos Lew , Ratos Sprague-Dawley , Taxa de Sobrevida , Temozolomida , Carga Tumoral
9.
ACS Nano ; 11(3): 3038-3051, 2017 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-28196324

RESUMO

Quantum dots (QDs), semiconductor nanocrystals, are fluorescent nanoparticles of growing interest as an imaging tool of a diseased tissue. However, a major concern is their biocompatibility, cytotoxicity, and fluorescence instability in biological milieu, impeding their use in biomedical applications, in general, and for inflammation imaging, in particular. In addition, for an efficient fluorescent signal at the desired tissue, and avoiding systemic biodistribution and possible toxicity, targeting is desired. We hypothesized that phagocytic cells of the innate immunity system (mainly circulating monocytes) can be exploited as transporters of specially designed liposomes containing QDs to the inflamed tissue. We developed a liposomal delivery system of QDs (LipQDs) characterized with high encapsulation yield, enhanced optical properties including far-red emission wavelength and fluorescent stability, high quantum yield, and protracted fluorescent decay lifetime. Treatment with LipQDs, rather than free QDs, exhibited high accumulation and retention following intravenous administration in carotid-injured rats (an inflammatory model). QD-monocyte colocalization was detected in the inflamed arterial segment only following treatment with LipQDs. No cytotoxicity was observed following LipQD treatment in cell cultures, and changes in liver enzymes and gross histopathological changes were not detected in mice and rats, respectively. Our results suggest that the LipQD formulation could be a promising strategy for imaging inflammation.


Assuntos
Sistemas de Liberação de Medicamentos , Inflamação/diagnóstico por imagem , Monócitos/química , Monócitos/metabolismo , Imagem Óptica , Pontos Quânticos/química , Animais , Compostos de Cádmio/química , Células Cultivadas , Lipossomos/química , Lipossomos/farmacocinética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Células RAW 264.7 , Ratos , Ratos Endogâmicos , Compostos de Selênio/química , Sulfetos/química , Distribuição Tecidual , Compostos de Zinco/química
10.
J Control Release ; 229: 163-171, 2016 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-27012977

RESUMO

Cationic antimicrobial peptides (AMPs) are part of the innate immunity, and act against a wide variety of pathogenic microorganisms by perturbation of the microorganism's plasma membrane. Although attractive for clinical applications, these agents suffer from limited stability and activity in vivo, as well as non-specific interaction with host biological membranes, leading to cytotoxic adverse effects. We hypothesized that encapsulation of AMPs within liposomes could result in reduced cytotoxicity, and with enhanced stability as well as bioactivity against herpes simplex virus 1 (HSV-1). We formulated nano-sized liposomal formulations of LL-37 and indolicidin, and their physicochemical properties, cellular uptake, in vitro cytotoxicity and antiviral efficacy have been determined. Lower cytotoxicity of LL-37 liposomes was found in comparison to indolicidin liposomes attributed to the superior physicochemical properties, and to the different degree of interaction with the liposomal membrane. The disc-like shaped LL-37 liposomes (106.8±10.1nm, shelf-life stability of >1year) were taken up more rapidly and to a significantly higher extent than the free peptide by human keratinocyte cell line (HaCaT), remained intact within the cells, followed by release of the active peptide within the cytoplasm and migration of the vesicles' lipids to the plasma membrane. LL-37 liposomes were found significantly less toxic than both the free agent and liposomal indolicidin. In the new 3D epidermis model (immortalized primary keratinocytes) liposomal LL-37 treatment (>20µM), but not free LL-37, efficiently protected the epidermis, inhibiting HSV-1 infection. This positive antiviral effect was obtained with no cytotoxicity even at very high concentrations (400µM). Thus, the antiviral activity of encapsulated LL-37 was significantly improved, expanding its therapeutic window. Liposomal LL-37 appears to be a promising delivery system for HSV therapy.


Assuntos
Peptídeos Catiônicos Antimicrobianos/administração & dosagem , Antivirais/administração & dosagem , Herpesvirus Humano 1/efeitos dos fármacos , Técnicas de Cultura de Células , Linhagem Celular , Células Cultivadas , Epiderme/virologia , Prepúcio do Pênis/citologia , Humanos , Queratinócitos/virologia , Lipídeos/química , Lipossomos , Masculino
11.
J Leukoc Biol ; 96(3): 491-501, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24823811

RESUMO

Nonhuman primates are critical animal models for the study of human disorders and disease and offer a platform to assess the role of immune cells in pathogenesis via depletion of specific cellular subsets. However, this model is currently hindered by the lack of reagents that safely and specifically ablate myeloid cells of the monocyte/macrophage Lin. Given the central importance of macrophages in homeostasis and host immunity, development of a macrophage-depletion technique in nonhuman primates would open new avenues of research. Here, using LA at i.v. doses as low as 0.1 mg/kg, we show a >50% transient depletion of circulating monocytes and tissue-resident macrophages in RMs by an 11-color flow cytometric analysis. Diminution of monocytes was followed rapidly by emigration of monocytes from the bone marrow, leading to a rebound of monocytes to baseline levels. Importantly, LA was well-tolerated, as no adverse effects or changes in gross organ function were observed during depletion. These results advance the ex vivo study of myeloid cells by flow cytometry and pave the way for in vivo studies of monocyte/macrophage biology in nonhuman primate models of human disease.


Assuntos
Alendronato/farmacologia , Separação Celular/métodos , Modelos Animais de Doenças , Citometria de Fluxo/métodos , Macaca mulatta/imunologia , Macrófagos/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Alendronato/administração & dosagem , Alendronato/toxicidade , Animais , Medula Óssea/efeitos dos fármacos , Contagem de Células , Movimento Celular/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Injeções Intraperitoneais , Injeções Intravenosas , Lipossomos , Células Mieloides/citologia , Células Mieloides/efeitos dos fármacos
12.
Clin Exp Metastasis ; 29(5): 441-56, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22407340

RESUMO

Bone sialoprotein (BSP) and osteopontin (OPN) are important factors in the metastasis of breast cancer, which were examined as targets for antineoplastic therapy by siRNA. In addition, the effect of gene silencing on their transcription factor Runx2 and their interaction partners integrin ß(3) and matrix metalloproteinase 2 was studied. The effect of siRNAs directed against these genes was assessed by monitoring expression levels followed by functional assays in cell culture as well as skeletal metastases caused by human MDA-MB-231(luc) breast cancer cells in nude rats. Upon silencing of the targets, cell migration was profoundly impaired (p < 0.001 for BSP-siRNA), but the impact on proliferation was low. Systemic administration by osmotic mini-pumps of BSP-siRNA but not OPN-siRNA decreased osteolytic lesions (p = 0.067). Extraosseous tumour growth was not affected. As an alternative approach, non-viral, polymeric based formulations of siRNAs in nanoparticles (NP) were developed. Locoregional administration of the two siRNAs targeting OPN and BSP encapsulated in these biodegradable NP reduced skeletal lesions even more efficiently (p = 0.03). Compared to systemic administration, this treatment caused not only a more pronounced anti-osteolytic effect at a 25-fold lower total siRNA dose, but also had a slight reducing effect on tumour incidence (p = 0.095). In conclusion, the siRNA treatment had a small effect on cellular proliferation but a significant efficacy against migration of and osteolysis induced by MDA-MB-231 cells. Our data underline that siRNA mediated knockdown is a powerful tool for identifying targets for pharmacological intervention. In addition, encapsulation of siRNA into biodegradable NP is a strategy, which promises well for using siRNA.


Assuntos
Neoplasias Ósseas/prevenção & controle , Neoplasias da Mama/prevenção & controle , Movimento Celular , Sialoproteína de Ligação à Integrina/metabolismo , Osteólise/prevenção & controle , Osteopontina/metabolismo , Animais , Western Blotting , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proliferação de Células , Feminino , Humanos , Sialoproteína de Ligação à Integrina/antagonistas & inibidores , Sialoproteína de Ligação à Integrina/genética , Osteólise/metabolismo , Osteólise/patologia , Osteopontina/antagonistas & inibidores , Osteopontina/genética , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Ratos , Ratos Nus , Reação em Cadeia da Polimerase em Tempo Real , Células Tumorais Cultivadas
13.
J Control Release ; 161(2): 619-27, 2012 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-22178594

RESUMO

The current treatment for coronary restenosis following balloon angioplasty involves the use of a mechanical or drug eluting stent (DES). The advent of DES systems has effectively allayed much of the challenge of restenosis that has plagued the success of percutaneous coronary interventions (PCI). However, there are certain limitations to DES use, among which is late stent thrombosis. Innate immunity and inflammation are of major importance in the overreaction of the wound healing response to PCI-induced vascular injury, which leads to restenosis. Liposomes containing alendronate have been shown to deplete circulating monocytes and reduce experimental restenosis. This review presents a unique systemic approach for treating restenosis with alendronate liposomal nano-carriers and reports on its formulation development, formulation variables affecting monocyte/macrophage targeting, pharmacokinetics (PK) and biodistribution, in vitro and in vivo anti-inflammatory effect, and the recent results of the phase II clinical trial.


Assuntos
Alendronato/administração & dosagem , Conservadores da Densidade Óssea/administração & dosagem , Reestenose Coronária/tratamento farmacológico , Alendronato/farmacocinética , Animais , Conservadores da Densidade Óssea/farmacocinética , Reestenose Coronária/imunologia , Humanos , Lipossomos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Monócitos/efeitos dos fármacos , Monócitos/imunologia
14.
Adv Exp Med Biol ; 733: 165-79, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22101722

RESUMO

Circulating γδ T cells are cytotoxic lymphocytes that are unique to primates. Recent -studies have shown that amino-bisphosphonates (nBP) activate γδ T cells to kill tumor cells in an indirect mechanism, which requires antigen presenting cells (APC). We hypothesized that selective targeting of nBP to monocytes would result in a more potent γδ T cells activation in circulation, and in tissue associated macrophages (TAM) following monocytes-laden drug extravasation and liposomes accumulation at the tumor site. In addition, inhibition of TAM by alendronate liposomes (ALN-L) is expected. ALN was targeted exclusively to monocytes, but not to lymphocytes, by encapsulating it in negatively-charged liposomes. The proportion of human γd-T cells in the CD3(+) population following treatment with ALN-L or the free drug was increased, from 5.6 ± 0.4% to 50.9 ;± 12.2% and 49.5 ± 12.9%, respectively. ALN solution and liposomes treatments resulted in an increased, and in a dose dependent manner, TNFα secretion from h-PBMC. Preliminary results showed that ALN-L inhibited tumor growth in a nude mouse breast tumor model. It is suggested that enhanced activation of γδ T cells could be obtained due to interaction with circulating monocytes as well as by TAM endocytosing liposomal nBP leading to a potentiated anti-tumor effect of nBP. It should be noted that this could be validated only in primates/humans since γδ T cells are unique in these species.


Assuntos
Alendronato/farmacologia , Antineoplásicos/farmacologia , Lipossomos/farmacologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Alendronato/química , Alendronato/farmacocinética , Análise de Variância , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , Feminino , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Lipossomos/química , Lipossomos/farmacocinética , Ativação Linfocitária/efeitos dos fármacos , Neoplasias Mamárias Experimentais/tratamento farmacológico , Camundongos , Camundongos Nus , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Proc Natl Acad Sci U S A ; 108(48): 19347-52, 2011 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-22087004

RESUMO

Following recent successes with percutaneous coronary intervention (PCI) for treating coronary artery disease (CAD), many challenges remain. In particular, mechanical injury from the procedure results in extensive endothelial denudation, exposing the underlying collagen IV-rich basal lamina, which promotes both intravascular thrombosis and smooth muscle proliferation. Previously, we reported the engineering of collagen IV-targeting nanoparticles (NPs) and demonstrated their preferential localization to sites of arterial injury. Here, we develop a systemically administered, targeted NP system to deliver an antiproliferative agent to injured vasculature. Approximately 60-nm lipid-polymeric NPs were surface functionalized with collagen IV-targeting peptides and loaded with paclitaxel. In safety studies, the targeted NPs showed no signs of toxicity and a ≥3.5-fold improved maximum tolerated dose versus paclitaxel. In efficacy studies using a rat carotid injury model, paclitaxel (0.3 mg/kg or 1 mg/kg) was i.v. administered postprocedure on days 0 and 5. The targeted NP group resulted in lower neointima-to-media (N/M) scores at 2 wk versus control groups of saline, paclitaxel, or nontargeted NPs. Compared with sham-injury groups, an ∼50% reduction in arterial stenosis was observed with targeted NP treatment. The combination of improved tolerability, sustained release, and vascular targeting could potentially provide a safe and efficacious option in the management of CAD.


Assuntos
Reestenose Coronária/prevenção & controle , Nanopartículas/uso terapêutico , Neointima/prevenção & controle , Paclitaxel/uso terapêutico , Animais , Colágeno Tipo IV/metabolismo , Imuno-Histoquímica , Masculino , Camundongos , Paclitaxel/metabolismo , Peptídeos/metabolismo , Ratos , Ratos Sprague-Dawley
16.
Drug Deliv ; 17(6): 408-18, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20429847

RESUMO

Efficient and specific delivery of antisenses (ASs) and protection of the sequences from degradation are critical factors for effective therapy. Sustained release nanoparticles (NP) offer increased resistance to nuclease degradation, increased amounts of AS uptake, and the possibility of control in dosing and sustained duration of AS administration. The biodegradable and biocompatible poly(D,L-lactic-co-glycolic acid) copolymer (PLGA) was utilized to encapsulate AS directed against osteopontin (OPN), which is a promising therapeutic target in mammary carcinoma. Whole body biodistribution of OPN AS NP was evaluated in comparison to naked AS, in intact and mammary carcinoma metastasis model bearing rats. Naked and NP encapsulated AS exhibited different biodistribution profiles. AS NP, in contrast to naked AS, tended to accumulate mostly in the spleen, liver, and at the tumor inoculation site. Drug levels in intact organs were negligible. The elimination of naked AS was faster, due to rapid degradation of the unprotected sequence. It is concluded that AS NP protect the AS from degradation, provide efficient AS delivery to the tumor tissue, and minimize AS accumulation in intact organs due to the AS sustained release profile as well as the favorable NP physicochemical properties.


Assuntos
Antineoplásicos/farmacocinética , Elementos Antissenso (Genética)/farmacocinética , Neoplasias Ósseas , Carcinoma , Portadores de Fármacos/farmacocinética , Neoplasias Mamárias Experimentais , Nanopartículas/química , Animais , Antineoplásicos/análise , Antineoplásicos/sangue , Antineoplásicos/urina , Elementos Antissenso (Genética)/análise , Elementos Antissenso (Genética)/sangue , Elementos Antissenso (Genética)/urina , Neoplasias Ósseas/sangue , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/secundário , Neoplasias Ósseas/urina , Carcinoma/sangue , Carcinoma/tratamento farmacológico , Carcinoma/secundário , Carcinoma/urina , Linhagem Celular Tumoral , Preparações de Ação Retardada/análise , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/uso terapêutico , Portadores de Fármacos/análise , Sistemas de Liberação de Medicamentos , Feminino , Humanos , Ácido Láctico/análise , Ácido Láctico/química , Ácido Láctico/uso terapêutico , Masculino , Neoplasias Mamárias Experimentais/sangue , Neoplasias Mamárias Experimentais/tratamento farmacológico , Neoplasias Mamárias Experimentais/urina , Nanopartículas/análise , Nanopartículas/uso terapêutico , Osteopontina/genética , Tamanho da Partícula , Ácido Poliglicólico/análise , Ácido Poliglicólico/química , Ácido Poliglicólico/uso terapêutico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Ratos Nus , Distribuição Tecidual , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
17.
J Control Release ; 146(2): 182-95, 2010 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-20359513

RESUMO

Partial inactivation and transient depletion of monocytes/macrophages by liposomal bisphosphonates (LIP-BPs) is widely experimented in various inflammatory disorders including restenosis. Previous studies on activation of cytokines by LIP-BPs are limited to certain cell lines. Moreover, the correlation between in vitro and in vivo studies and complement (C) activation has not been reported. We report here a comprehensive study on the bioactivity of LIP-BPs on various cells' internalization and proliferation, mechanism of cell death, cytokines (in vitro and in vivo) and C activation (in the rat, rabbit and pig). The role of the following parameters has been determined i) drug type (clodronate/alendronate); ii) vesicles size (60-800nm); iii) charge (neutral/negative/ positive); and iv) cell culture type (various cell lines and primary cultures). It was found that monocyte/macrophage inhibition and cytokine activation depend on the cell type, with a limited correlation to the bioactivity obtained in the rat and rabbit models of restenosis. Negatively charged liposomes (85+/-20nm) effectively depleted rabbit's monocytes (67% depletion), with a minor activation of cytokines and no C activation. It is concluded that cell culture studies are insufficient for assessing cytokine activation, and that by controlling LIP-BP properties (size, charge and drug type) optimal bioactivity could be achieved.


Assuntos
Ativação do Complemento/efeitos dos fármacos , Reestenose Coronária/tratamento farmacológico , Citocinas/imunologia , Difosfonatos/administração & dosagem , Difosfonatos/uso terapêutico , Lipossomos/química , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular , Células Cultivadas , Reestenose Coronária/imunologia , Difosfonatos/imunologia , Difosfonatos/farmacologia , Humanos , Lipossomos/imunologia , Masculino , Camundongos , Monócitos/citologia , Monócitos/efeitos dos fármacos , Coelhos , Ratos
18.
AAPS J ; 12(2): 181-7, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20143196

RESUMO

Monocytes, macrophages, and inflammation play a key role in the process of neointimal proliferation and restenosis. The present study evaluated whether systemic and transient depletion of monocytes could be obtained by a single intravenous (IV) injection of simvastatin liposomes, for the inhibition of neointima formation. Balloon-injured carotid artery rats (n = 30) were randomly assigned to treatment groups of free simvastatin, simvastatin in liposomes (3 mg/kg), and saline (control). Stenosis and neointima to media ratio (N/M) were determined 14 days following single IV injection at the time of injury by morphometric analysis. Depletion of circulating monocytes was determined by flow cytometry analyzes of blood specimens. Inhibition of RAW264.7, J774, and THP-1 proliferation by simvastatin-loaded liposomes and free simvastatin was determined by the 3-(4, 5-dimethylthiazolyl-2)-2, 5- diphenyltetrazolium bromide assay. Simvastatin liposomes were successfully formulated and were found to be 1.5-2 times more potent than the free drug in suppressing the proliferation of monocytes/macrophages in cell cultures of RAW 264.7, J774, and THP-1. IV injection of liposomal simvastatin to carotid-injured rats (3 mg/kg, n = 4) resulted in a transient depletion of circulating monocytes, significantly more prolonged than that observed following treatment with free simvastatin. Administration to balloon-injured rats suppressed neointimal growth. N/M at 14 days was 1.56 +/- 0.16 and 0.90 +/- 0.12, control and simvastatin liposomes, respectively. One single systemic administration of liposomal simvastatin at the time of injury significantly suppresses neointimal formation in the rat model of restenosis, mediated via a partial and transient depletion of circulating monocytes.


Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hiperplasia/tratamento farmacológico , Sinvastatina/administração & dosagem , Sinvastatina/uso terapêutico , Animais , Lesões das Artérias Carótidas/tratamento farmacológico , Lesões das Artérias Carótidas/patologia , Cateterismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Química Farmacêutica , Sistemas de Liberação de Medicamentos , Oclusão de Enxerto Vascular/tratamento farmacológico , Oclusão de Enxerto Vascular/prevenção & controle , Lipossomos , Masculino , Monócitos/efeitos dos fármacos , Ratos
19.
Proc Natl Acad Sci U S A ; 107(5): 2213-8, 2010 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-20133865

RESUMO

There are a number of challenges associated with designing nanoparticles for medical applications. We define two challenges here: (i) conventional targeting against up-regulated cell surface antigens is limited by heterogeneity in expression, and (ii) previous studies suggest that the optimal size of nanoparticles designed for systemic delivery is approximately 50-150 nm, yet this size range confers a high surface area-to-volume ratio, which results in fast diffusive drug release. Here, we achieve spatial control by biopanning a phage library to discover materials that target abundant vascular antigens exposed in disease. Next, we achieve temporal control by designing 60-nm hybrid nanoparticles with a lipid shell interface surrounding a polymer core, which is loaded with slow-eluting conjugates of paclitaxel for controlled ester hydrolysis and drug release over approximately 12 days. The nanoparticles inhibited human aortic smooth muscle cell proliferation in vitro and showed greater in vivo vascular retention during percutaneous angioplasty over nontargeted controls. This nanoparticle technology may potentially be used toward the treatment of injured vasculature, a clinical problem of primary importance.


Assuntos
Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/lesões , Sistemas de Liberação de Medicamentos , Nanopartículas/administração & dosagem , Sequência de Aminoácidos , Animais , Antígenos/genética , Antígenos/metabolismo , Engenharia Biomédica , Células Cultivadas , Preparações de Ação Retardada/administração & dosagem , Humanos , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/lesões , Nanomedicina , Nanopartículas/química , Paclitaxel/administração & dosagem , Biblioteca de Peptídeos , Ratos , Ratos Sprague-Dawley
20.
Int J Cancer ; 126(7): 1749-60, 2010 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-19739076

RESUMO

Poor prognosis in mammary carcinoma is associated with a certain expression profile of a defined set of genes including osteopontin and bone sialoprotein. Efficient and specific delivery of antisenses (AS) and a protection of the sequences from degradation are the crucial conditions for AS therapeutic efficiency. We hypothesized that effective and safe AS delivery direceted against these genes could be achieved by polymeric nanoparticles (NP) fabricated from a biocompatible polymer. Due to their nano-size range and small negative charge, AS-NP can overcome the absorption barrier offering increased resistance to nuclease degradation, sustained duration of AS administration, and consequently, prolonged antisense action. The ASs designed against OPN and BSP-II were successfully encapsulated in NP composed of the biodegradable and biocompatible polylactide-co-glycolide polymer (PLGA), exhibiting sustained release and stability of the ASs. The therapeutic efficacy of the AS-NP delivery system was examined in vitro, and in a breast cancer bone metastasis animal model of MDA-MB-231 human breast cancer cells in nude rats. Treatment with OPN-AS or BSP-AS loaded NP in comparison with osmotic mini-pumps (locoregional injection and SC implants, respectively) resulted in a significant decrease in both, tumor bone metastasis incidence and in the size of the lesions in rats with metastases. Despite its smaller dose, AS-NP exhibited a better therapeutic efficacy than osmotic mini-pumps in terms of lesion ratio at later time periods (8-12 weeks). It may be concluded that AS delivery by NP is a promising therapeutic modality providing stability of the encapsulated AS and a sustained release.


Assuntos
Neoplasias Ósseas/terapia , Neoplasias da Mama/terapia , Sistemas de Liberação de Medicamentos , Ácido Láctico , Nanopartículas , Osteopontina/genética , Ácido Poliglicólico , Sialoglicoproteínas/genética , Animais , Neoplasias Ósseas/genética , Neoplasias Ósseas/secundário , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Feminino , Humanos , Sialoproteína de Ligação à Integrina , Oligonucleotídeos Antissenso/farmacologia , Osteopontina/metabolismo , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Ratos Nus , Sialoglicoproteínas/metabolismo , Células Tumorais Cultivadas
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