Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
1.
Neurobiol Dis ; 187: 106307, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37739136

RESUMO

Air pollution poses a significant threat to human health, though a clear understanding of its mechanism remains elusive. In this study, we sought to better understand the effects of various sized particulate matter from polluted air on Alzheimer's disease (AD) development using an AD mouse model. We exposed transgenic Alzheimer's mice in their prodromic stage to different sized particulate matter (PM), with filtered clean air as control. After 3 or 6 months of exposure, mouse brains were harvested and analyzed. RNA-seq analysis showed that various PM have differential effects on the brain transcriptome, and these effects seemed to correlate with PM size. Many genes and pathways were affected after PM exposure. Among them, we found a strong activation in mRNA Nonsense Mediated Decay pathway, an inhibition in pathways related to transcription, neurogenesis and survival signaling as well as angiogenesis, and a dramatic downregulation of collagens. Although we did not detect any extracellular Aß plaques, immunostaining revealed that both intracellular Aß1-42 and phospho-Tau levels were increased in various PM exposure conditions compared to the clean air control. NanoString GeoMx analysis demonstrated a remarkable activation of immune responses in the PM exposed mouse brain. Surprisingly, our data also indicated a strong activation of various tumor suppressors including RB1, CDKN1A/p21 and CDKN2A/p16. Collectively, our data demonstrated that exposure to airborne PM caused a profound transcriptional dysregulation and accelerated Alzheimer's-related pathology.

2.
ACS Nano ; 16(8): 11815-11832, 2022 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-35961653

RESUMO

The ability to cross the blood-brain barrier (BBB) is critical for targeted therapy of the central nerve system (CNS). Six peptide vectors were covalently attached to a 50 kDa poly(ß-l-malic acid)-trileucine polymer forming P/LLL(40%)/vector conjugates. The vectors were Angiopep-2 (AP2), B6, Miniap-4 (M4), and d-configurated peptides D1, D3, and ACI-89, with specificity for transcytosis receptors low-density lipoprotein receptor-related protein-1 (LRP-1), transferrin receptor (TfR), bee venom-derived ion channel, and Aß/LRP-1 related transcytosis complex, respectively. The BBB-permeation efficacies were substantially increased ("boosted") in vector conjugates of P/LLL(40%). We have found that the copolymer group binds at the endothelial membrane and, by an allosterically membrane rearrangement, exposes the sites for vector-receptor complex formation. The specificity of vectors is indicated by competition experiments with nonconjugated vectors. P/LLL(40%) does not function as an inhibitor, suggesting that the copolymer binding site is eliminated after binding of the vector-nanoconjugate. The two-step mechanism, binding to endothelial membrane and allosteric exposure of transcytosis receptors, is supposed to be an integral feature of nanoconjugate-transcytosis pathways. In vivo brain delivery signatures of the nanoconjugates were recapitulated in mouse brains of normal, tumor (glioblastoma), and Alzheimer's disease (AD) models. BBB permeation of the tumor was most efficient, followed by normal and then AD-like brain. In tumor-bearing and normal brains, AP2 was the top performing vector; however, in AD models, D3 and D1 peptides were superior ones. The TfR vector B6 was equally efficient in normal and AD-model brains. Cross-permeation efficacies are manifested through modulated vector coligation and dosage escalation such as supra-linear dose dependence and crossover transcytosis activities.


Assuntos
Doença de Alzheimer , Barreira Hematoencefálica , Animais , Camundongos , Barreira Hematoencefálica/metabolismo , Doença de Alzheimer/patologia , Nanoconjugados , Transcitose , Peptídeos/química , Polímeros/farmacologia , Peptídeos beta-Amiloides/metabolismo
3.
Nanomaterials (Basel) ; 11(11)2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34835657

RESUMO

Glioblastoma (GBM) is the most prevalent primary brain cancer in the pediatric and adult population. It is known as an untreatable tumor in urgent need of new therapeutic approaches. The objective of this work was to develop multifunctional nanomedicines to treat GBM in clinical practice using combination therapy for several targets. We developed multifunctional nanopolymers (MNPs) based on a naturally derived biopolymer, poly(ß-L-malic) acid, which are suitable for central nervous system (CNS) treatment. These MNPs contain several anticancer functional moieties with the capacity of crossing the blood-brain barrier (BBB), targeting GBM cells and suppressing two important molecular markers, tyrosine kinase transmembrane receptors EGFR/EGFRvIII and c-Myc nuclear transcription factor. The reproducible syntheses of MNPs where monoclonal antibodies are replaced with AP-2 peptide for effective BBB delivery were presented. The active anticancer inhibitors of mRNA/protein syntheses were Morpholino antisense oligonucleotides (AONs). Two ways of covalent AON-polymer attachments with and without disulfide bonds were explored. These MNPs bearing AONs to EGFR/EGFRvIII and c-Myc, as well as in a combination with the polymer-attached checkpoint inhibitor anti-PD-1 antibody, orchestrated a multi-pronged attack on intracranial mouse GBM to successfully block tumor growth and significantly increase survival of brain tumor-bearing animals.

4.
Nanomaterials (Basel) ; 11(11)2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34835760

RESUMO

Research has increasingly focused on the delivery of high, often excessive amounts of drugs, neglecting negative aspects of the carrier's physical preconditions and biocompatibility. Among them, little attention has been paid to "small but beautiful" design of vehicle and multiple cargo to achieve effortless targeted delivery into deep tissue. The design of small biopolymers for deep tissue targeted delivery of multiple imaging agents and therapeutics (mini-nano carriers) emphasizes linear flexible polymer platforms with a hydrodynamic diameter of 4 nm to 10 nm, geometrically favoring dynamic juxtaposition of ligands to host receptors, and economic drug content. Platforms of biodegradable, non-toxic poly(ß-l-malic acid) of this size carrying multiple chemically bound, optionally nature-derived or synthetic affinity peptides and drugs for a variety of purposes are described in this review with specific examples. The size, shape, and multiple attachments to membrane sites accelerate vascular escape and fast blood clearance, as well as the increase in medical treatment and contrasts for tissue imaging. High affinity antibodies routinely considered for targeting, such as the brain through the blood-brain barrier (BBB), are replaced by moderate affinity binding peptides (vectors), which penetrate at high influxes not achievable by antibodies.

5.
Nanomedicine ; 32: 102332, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33181273

RESUMO

Human diabetic corneas develop delayed wound healing, epithelial stem cell dysfunction, recurrent erosions, and keratitis. Adenoviral gene therapy modulating c-Met, cathepsin F and MMP-10 normalized wound healing and epithelial stem cells in organ-cultured diabetic corneas but showed toxicity in stem cell-enriched cultured limbal epithelial cells (LECs). For a safer treatment, we engineered a novel nanobiopolymer (NBC) that carried antisense oligonucleotide (AON) RNA therapeutics suppressing cathepsin F or MMP-10, and miR-409-3p that inhibits c-Met. NBC was internalized by LECs through transferrin receptor (TfR)-mediated endocytosis, inhibited cathepsin F or MMP-10 and upregulated c-Met. Non-toxic NBC modulating c-Met and cathepsin F accelerated wound healing in diabetic LECs and organ-cultured corneas vs. control NBC. NBC treatment normalized levels of stem cell markers (keratins 15 and 17, ABCG2, and ΔNp63), and signaling mediators (p-EGFR, p-Akt and p-p38). Non-toxic nano RNA therapeutics thus present a safe alternative to viral gene therapy for normalizing diabetic corneal cells.


Assuntos
Córnea/patologia , Diabetes Mellitus/patologia , Células Epiteliais/patologia , Nanopartículas/química , Polímeros/química , RNA/uso terapêutico , Células-Tronco/patologia , Cicatrização , Adenoviridae/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/metabolismo , Sobrevivência Celular , Células Cultivadas , Córnea/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/virologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nanopartículas/ultraestrutura , Oligonucleotídeos Antissenso/farmacologia , RNA/farmacologia , Receptores de Superfície Celular/metabolismo , Transdução de Sinais/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Cicatrização/efeitos dos fármacos
7.
Int J Nanomedicine ; 15: 3057-3070, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32431501

RESUMO

BACKGROUND: Position of gadolinium atom(s) plays a key role in contrast enhancement of gadolinium-based contrast agents. To gain a better understanding of effects of distance of gadolinium in relation to the nanoconjugate platform, we designed and synthesized single- and multi-arm ("star") gadolinium conjugates equipped with antibody and peptides for targeting. The contrast agents were studied for their tumor imaging performance in a glioma mouse model. MATERIALS AND METHODS: Antibody- and peptide-targeted nano contrast agents (NCAs) were synthesized using polymalic acid platforms of different sizes. Gadolinium-DOTA and intermediates were attached as amides and targeting agents such as antibodies and peptides as thioethers. For in vivo experiments, we used human U87MG xenografts as glioma models. Magnetic resonance imaging (MRI) was performed on a Bruker BioSpec 94/20USR 9.4 T small-animal scanner. Delivery of contrast agents across the blood-brain barrier was studied by fluorescent microscopy. RESULTS: All contrast agents accumulated into tumor and showed composition-dependent imaging performance. Peptide-targeted mini-NCAs had hydrodynamic diameters in the range 5.2-9.4 nm and antibody-targeted NCAs had diameters in the range 15.8-20.5 nm. Zeta potentials were in the range of -5.4--8.2 mV and -4.6--8.8 mV, respectively. NCAs showed superior relaxivities compared to MultiHance at 9.4 T. The signal enhancement indicated maximum accumulation in tumor 30-60 minutes after intravenous injection of the mouse tail vein. Only targeted NCAs were retained in tumor for up to 3 hours and displayed contrast enhancement. CONCLUSION: The novel targeted NCAs with star-PEG features displayed improved relaxivity and greater contrast compared with commercial MultiHance contrast agent. The enhancement by mini-NCAs showed clearance of tumor contrast after 3 hours providing a suitable time window for tumor diagnosis in clinics. The technology provides a great tool with the promise of differential MRI diagnosis of brain tumors.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Meios de Contraste/administração & dosagem , Glioblastoma/diagnóstico por imagem , Compostos Heterocíclicos/administração & dosagem , Imageamento por Ressonância Magnética/métodos , Compostos Organometálicos/administração & dosagem , Animais , Linhagem Celular Tumoral , Meios de Contraste/química , Meios de Contraste/farmacocinética , Modelos Animais de Doenças , Feminino , Humanos , Meglumina/administração & dosagem , Meglumina/análogos & derivados , Meglumina/farmacocinética , Camundongos Nus , Nanoestruturas/administração & dosagem , Nanoestruturas/química , Compostos Organometálicos/farmacocinética , Ensaios Antitumorais Modelo de Xenoenxerto
9.
J Control Release ; 320: 45-62, 2020 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-31923537

RESUMO

Magnetic nanoparticles in general, and iron oxide nanoparticles in particular, have been studied extensively during the past 20 years for numerous biomedical applications. The main applications of these nanoparticles are in magnetic resonance imaging (MRI), magnetic targeting, gene and drug delivery, magnetic hyperthermia for tumor treatment, and manipulation of the immune system by macrophage polarization for cancer treatment. Recently, considerable attention has been paid to magnetic particle imaging (MPI) because of its better sensitivity compared to MRI. In recent years, MRI and MPI have been combined as a dual or multimodal imaging method to enhance the signal in the brain for the early detection and treatment of brain pathologies. Because magnetic and iron oxide nanoparticles are so diverse and can be used in multiple applications such as imaging or therapy, they have attractive features for brain delivery. However, the greatest limitations for the use of MRI/MPI for imaging and treatment are in brain delivery, with one of these limitations being the brain-blood barrier (BBB). This review addresses the current status, chemical compositions, advantages and disadvantages, toxicity and most importantly the future directions for the delivery of iron oxide based substances across the blood-brain barrier for targeting, imaging and therapy of primary and metastatic tumors of the brain.


Assuntos
Neoplasias Encefálicas , Hipertermia Induzida , Nanopartículas de Magnetita , Nanopartículas , Barreira Hematoencefálica , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/terapia , Compostos Férricos , Humanos , Nanopartículas Magnéticas de Óxido de Ferro , Imageamento por Ressonância Magnética
10.
Nat Commun ; 10(1): 3850, 2019 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-31462642

RESUMO

Brain glioma treatment with checkpoint inhibitor antibodies to cytotoxic T-lymphocyte-associated antigen 4 (a-CTLA-4) and programmed cell death-1 (a-PD-1) was largely unsuccessful due to their inability to cross blood-brain barrier (BBB). Here we describe targeted nanoscale immunoconjugates (NICs) on natural biopolymer scaffold, poly(ß-L-malic acid), with covalently attached a-CTLA-4 or a-PD-1 for systemic delivery across the BBB and activation of local brain anti-tumor immune response. NIC treatment of mice bearing intracranial GL261 glioblastoma (GBM) results in an increase of CD8+ T cells, NK cells and macrophages with a decrease of regulatory T cells (Tregs) in the brain tumor area. Survival of GBM-bearing mice treated with NIC combination is significantly longer compared to animals treated with single checkpoint inhibitor-bearing NICs or free a-CTLA-4 and a-PD-1. Our study demonstrates trans-BBB delivery of tumor-targeted polymer-conjugated checkpoint inhibitors as an effective GBM treatment via activation of both systemic and local privileged brain tumor immune response.


Assuntos
Antineoplásicos Imunológicos/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Glioma/tratamento farmacológico , Imunoconjugados/administração & dosagem , Nanoconjugados/química , Animais , Antineoplásicos Imunológicos/farmacocinética , Biopolímeros/química , Barreira Hematoencefálica/metabolismo , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Antígeno CTLA-4/antagonistas & inibidores , Antígeno CTLA-4/imunologia , Linhagem Celular Tumoral/transplante , Modelos Animais de Doenças , Feminino , Glioma/imunologia , Glioma/patologia , Humanos , Imunoconjugados/química , Imunoconjugados/farmacocinética , Malatos/química , Camundongos , Permeabilidade , Physarum polycephalum/química , Polímeros/química , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Resultado do Tratamento
11.
Biomaterials ; 206: 146-159, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30933776

RESUMO

Maximal surgical resection of glioma remains the single most effective treatment. Tools to guide the resection while avoiding removal of normal brain tissues can aid surgeons in achieving optimal results. One strategy to achieve this goal is to rely upon interoperative fluorescence staining of tumor cells in vivo, that can be visualized by the surgeon during resection. Towards this goal we have designed a biodegradable fluorescent mini nano imaging agent (NIA) with high specificity for U87MG glioma cells and previously unmet high light emission. The NIA is the conjugate of polymalic acid (PMLA) with chlorotoxin for tumor targeting, indocyanine green (ICG) for NIR fluorescence and the tri-leucin peptide as fluorescence enhancer. PMLA as a multivalent platform carries several molecules of ICG and the other ligands. The NIA recognizes multiple sites on glioma cell surface, demonstrated by the effects of single and combined competitors. Systemic IV injection into xenogeneic mouse model carrying human U87MG glioblastoma indicated vivid tumor cell binding and internalization of NIA resulting in intensive and long-lasting tumor fluorescence. The NIA is shown to greatly improve tumor removal supporting its utility in clinical applications.


Assuntos
Glioblastoma/cirurgia , Malatos/química , Nanoconjugados/química , Polímeros/química , Venenos de Escorpião/química , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Verde de Indocianina/química , Camundongos , Espectroscopia de Luz Próxima ao Infravermelho , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Cancer Res ; 79(6): 1239-1251, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30659021

RESUMO

There is an unmet need for the treatment of glioblastoma multiforme (GBM). The extracellular matrix, including laminins, in the tumor microenvironment is important for tumor invasion and progression. In a panel of 226 patient brain glioma samples, we found a clinical correlation between the expression of tumor vascular laminin-411 (α4ß1γ1) with higher tumor grade and with expression of cancer stem cell (CSC) markers, including Notch pathway members, CD133, Nestin, and c-Myc. Laminin-411 overexpression also correlated with higher recurrence rate and shorter survival of GBM patients. We also showed that depletion of laminin-411 α4 and ß1 chains with CRISPR/Cas9 in human GBM cells led to reduced growth of resultant intracranial tumors in mice and significantly increased survival of host animals compared with mice with untreated cells. Inhibition of laminin-411 suppressed Notch pathway in normal and malignant human brain cell types. A nanobioconjugate potentially suitable for clinical use and capable of crossing blood-brain barrier was designed to block laminin-411 expression. Nanobioconjugate treatment of mice carrying intracranial GBM significantly increased animal survival and inhibited multiple CSC markers, including the Notch axis. This study describes an efficient strategy for GBM treatment via targeting a critical component of the tumor microenvironment largely independent of heterogeneous genetic mutations in glioblastoma.Significance: Laminin-411 expression in the glioma microenvironment correlates with Notch and other cancer stem cell markers and can be targeted by a novel, clinically translatable nanobioconjugate to inhibit glioma growth.


Assuntos
Sistemas CRISPR-Cas , Glioblastoma/patologia , Laminina/metabolismo , Nanopartículas/química , Células-Tronco Neoplásicas/patologia , Receptores Notch/metabolismo , Microambiente Tumoral , Animais , Apoptose , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Glioblastoma/metabolismo , Humanos , Laminina/antagonistas & inibidores , Laminina/genética , Camundongos , Camundongos Nus , Células-Tronco Neoplásicas/metabolismo , Prognóstico , Receptores Notch/genética , Transdução de Sinais , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
13.
ACS Nano ; 13(2): 1253-1271, 2019 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-30633492

RESUMO

One of the major problems facing the treatment of neurological disorders is the poor delivery of therapeutic agents into the brain. Our goal is to develop a multifunctional and biodegradable nanodrug delivery system that crosses the blood-brain barrier (BBB) to access brain tissues affected by neurological disease. In this study, we synthesized a biodegradable nontoxic ß-poly(l-malic acid) (PMLA or P) as a scaffold to chemically bind the BBB crossing peptides Angiopep-2 (AP2), MiniAp-4 (M4), and the transferrin receptor ligands cTfRL and B6. In addition, a trileucine endosome escape unit (LLL) and a fluorescent marker (rhodamine or rh) were attached to the PMLA backbone. The pharmacokinetics, BBB penetration, and biodistribution of nanoconjugates were studied in different brain regions and at multiple time points via optical imaging. The optimal nanoconjugate, P/LLL/AP2/rh, produced significant fluorescence in the parenchyma of cortical layers II/III, the midbrain colliculi, and the hippocampal CA1-3 cellular layers 30 min after a single intravenous injection; clearance was observed after 4 h. The nanoconjugate variant P/LLL/rh lacking AP2, or the variant P/AP2/rh lacking LLL, showed significantly less BBB penetration. The LLL moiety appeared to stabilize the nanoconjugate, while AP2 enhanced BBB penetration. Finally, nanoconjugates containing the peptides M4, cTfRL, and B6 displayed comparably little and/or inconsistent infiltration of brain parenchyma, likely due to reduced trans-BBB movement. P/LLL/AP2/rh can now be functionalized with intra-brain targeting and drug treatment moieties that are aimed at molecular pathways implicated in neurological disorders.


Assuntos
Barreira Hematoencefálica/química , Leucina/farmacocinética , Malatos/farmacocinética , Nanoconjugados/química , Peptídeos/farmacocinética , Polímeros/farmacocinética , Rodaminas/farmacocinética , Animais , Barreira Hematoencefálica/metabolismo , Sistemas de Liberação de Medicamentos , Injeções Intravenosas , Leucina/administração & dosagem , Leucina/química , Malatos/administração & dosagem , Malatos/química , Camundongos , Nanoconjugados/administração & dosagem , Peptídeos/administração & dosagem , Peptídeos/química , Polieletrólitos , Polímeros/administração & dosagem , Polímeros/química , Rodaminas/administração & dosagem , Rodaminas/química , Distribuição Tecidual
14.
Sci Rep ; 8(1): 5708, 2018 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-29632393

RESUMO

Air pollution is linked to brain inflammation, which accelerates tumorigenesis and neurodegeneration. The molecular mechanisms that connect air pollution with brain pathology are largely unknown but seem to depend on the chemical composition of airborne particulate matter (PM). We sourced ambient PM from Riverside, California, and selectively exposed rats to coarse (PM2.5-10: 2.5-10 µm), fine (PM<2.5: <2.5 µm), or ultrafine particles (UFPM: <0.15 µm). We characterized each PM type via atomic emission spectroscopy and detected nickel, cobalt and zinc within them. We then exposed rats separately to each PM type for short (2 weeks), intermediate (1-3 months) and long durations (1 year). All three metals accumulated in rat brains during intermediate-length PM exposures. Via RNAseq analysis we then determined that intermediate-length PM2.5-10 exposures triggered the expression of the early growth response gene 2 (EGR2), genes encoding inflammatory cytokine pathways (IL13-Rα1 and IL-16) and the oncogene RAC1. Gene upregulation occurred only in brains of rats exposed to PM2.5-10 and correlated with cerebral nickel accumulation. We hypothesize that the expression of inflammation and oncogenesis-related genes is triggered by the combinatorial exposure to certain metals and toxins in Los Angeles Basin PM2.5-10.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/veterinária , Encefalite/veterinária , Perfilação da Expressão Gênica/veterinária , Material Particulado/efeitos adversos , Poluentes Atmosféricos/análise , Animais , Química Encefálica , Neoplasias Encefálicas/induzido quimicamente , Neoplasias Encefálicas/genética , Encefalite/induzido quimicamente , Encefalite/genética , Encefalite/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Los Angeles , Níquel/análise , Especificidade de Órgãos , Tamanho da Partícula , Material Particulado/análise , Ratos , Análise de Sequência de RNA , Espectrofotometria Atômica , Fatores de Tempo
15.
Adv Drug Deliv Rev ; 113: 177-200, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28606739

RESUMO

Nanomedicine is a rapidly evolving form of therapy that holds a great promise for superior drug delivery efficiency and therapeutic efficacy than conventional cancer treatment. In this review, we attempt to cover the benefits and the limitations of current nanomedicines with special attention to covalent nano conjugates for imaging and drug delivery in the brain. The improvement in brain tumor treatment remains dismal despite decades of efforts in drug development and patient care. One of the major obstacles in brain cancer treatment is the poor drug delivery efficiency owing to the unique blood-brain barrier (BBB) in the CNS. Although various anti-cancer agents are available to treat tumors outside of the CNS, the majority fails to cross the BBB. In this regard, nanomedicines have increasingly drawn attention due to their multi-functionality and versatility. Nano drugs can penetrate BBB and other biological barriers, and selectively accumulate in tumor cells, while concurrently decreasing systemic toxicity.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/terapia , Sistemas de Liberação de Medicamentos , Imagem Molecular , Nanoconjugados/uso terapêutico , Nanomedicina , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Neoplasias Encefálicas/metabolismo , Humanos , Nanoconjugados/administração & dosagem , Nanoconjugados/efeitos adversos
16.
Nanomedicine ; 13(2): 631-639, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27520726

RESUMO

HER2+ breast cancer is one of the most aggressive forms of breast cancer. The new polymalic acid-based mini nanodrug copolymers are synthesized and specifically characterized to inhibit growth of HER2+ breast cancer. These mini nanodrugs are highly effective and in the clinic may substitute for trastuzumab (the marketed therapeutic antibody) and antibody-targeted nanobioconjugates. Novel mini nanodrugs are designed to have slender shape and small size. HER2+ cells were recognized by the polymer-attached trastuzumab-mimetic 12-mer peptide. Synthesis of the nascent cell-transmembrane HER2/neu receptors by HER2+ cells was inhibited by antisense oligonucleotides that prevented cancer cell proliferation and significantly reduced tumor size by more than 15 times vs. untreated control or PBS-treated group. We emphasize that the shape and size of mini nanodrugs can enhance penetration of multiple bio-barriers to facilitate highly effective treatment. Replacement of trastuzumab by the mimetic peptide favors reduced production costs and technical efforts, and a negligible immune response.


Assuntos
Anticorpos Monoclonais Humanizados/farmacocinética , Neoplasias da Mama/tratamento farmacológico , Receptor ErbB-2 , Trastuzumab/farmacocinética , Anticorpos Monoclonais Humanizados/administração & dosagem , Linhagem Celular Tumoral , Humanos , Nanopartículas/química , Peptídeos/uso terapêutico , Trastuzumab/administração & dosagem
17.
J Control Release ; 244(Pt A): 14-23, 2016 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-27825958

RESUMO

Glioblastoma multiforme (GBM) remains the deadliest brain tumor in adults. GBM tumors are also notorious for drug and radiation resistance. To inhibit GBMs more effectively, polymalic acid-based blood-brain barrier crossing nanobioconjugates were synthesized that are delivered to the cytoplasm of cancer cells and specifically inhibit the master regulator serine/threonine protein kinase CK2 and the wild-type/mutated epidermal growth factor receptor (EGFR/EGFRvIII), which are overexpressed in gliomas according to The Cancer Genome Atlas (TCGA) GBM database. Two xenogeneic mouse models bearing intracranial human GBMs from cell lines LN229 and U87MG that expressed both CK2 and EGFR at different levels were used. Simultaneous knockdown of CK2α and EGFR/EGFRvIII suppressed their downstream prosurvival signaling. Treatment also markedly reduced the expression of programmed death-ligand 1 (PD-L1), a negative regulator of cytotoxic lymphocytes. Downregulation of CK2 and EGFR also caused deactivation of heat shock protein 90 (Hsp90) co-chaperone Cdc37, which may suppress the activity of key cellular kinases. Inhibition of either target was associated with downregulation of the other target as well, which may underlie the increased efficacy of the dual nanobioconjugate that is directed against both CK2 and EGFR. Importantly, the single nanodrugs, and especially the dual nanodrug, markedly suppressed the expression of the cancer stem cell markers c-Myc, CD133, and nestin, which could contribute to the efficacy of the treatments. In both tumor models, the nanobioconjugates significantly increased (up to 2-fold) animal survival compared with the PBS-treated control group. The versatile nanobioconjugates developed in this study, with the abilities of anti-cancer drug delivery across biobarriers and the inhibition of key tumor regulators, offer a promising nanotherapeutic approach to treat GBMs, and to potentially prevent drug resistance and retard the recurrence of brain tumors.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Caseína Quinase II/antagonistas & inibidores , Receptores ErbB/antagonistas & inibidores , Glioblastoma/tratamento farmacológico , Nanoconjugados/uso terapêutico , Adulto , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/química , Barreira Hematoencefálica/metabolismo , Neoplasias Encefálicas/metabolismo , Caseína Quinase II/genética , Linhagem Celular Tumoral , Receptores ErbB/genética , Feminino , Glioblastoma/metabolismo , Humanos , Malatos/química , Camundongos , Camundongos Nus , Nanoconjugados/química , Células-Tronco Neoplásicas , Oligonucleotídeos Antissenso/química , Oligonucleotídeos Antissenso/uso terapêutico , Polietilenoglicóis/química , Polímeros/química , Transdução de Sinais , Propriedades de Superfície
18.
ACS Nano ; 9(5): 5594-608, 2015 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-25906400

RESUMO

Differential diagnosis of brain magnetic resonance imaging (MRI) enhancement(s) remains a significant problem, which may be difficult to resolve without biopsy, which can be often dangerous or even impossible. Such MRI enhancement(s) can result from metastasis of primary tumors such as lung or breast, radiation necrosis, infections, or a new primary brain tumor (glioma, meningioma). Neurological symptoms are often the same on initial presentation. To develop a more precise noninvasive MRI diagnostic method, we have engineered a new class of poly(ß-l-malic acid) polymeric nanoimaging agents (NIAs). The NIAs carrying attached MRI tracer are able to pass through the blood-brain barrier (BBB) and specifically target cancer cells for efficient imaging. A qualitative/quantitative "MRI virtual biopsy" method is based on a nanoconjugate carrying MRI contrast agent gadolinium-DOTA and antibodies recognizing tumor-specific markers and extravasating through the BBB. In newly developed double tumor xenogeneic mouse models of brain metastasis this noninvasive method allowed differential diagnosis of HER2- and EGFR-expressing brain tumors. After MRI diagnosis, breast and lung cancer brain metastases were successfully treated with similar tumor-targeted nanoconjugates carrying molecular inhibitors of EGFR or HER2 instead of imaging contrast agent. The treatment resulted in a significant increase in animal survival and markedly reduced immunostaining for several cancer stem cell markers. Novel NIAs could be useful for brain diagnostic MRI in the clinic without currently performed brain biopsies. This technology shows promise for differential MRI diagnosis and treatment of brain metastases and other pathologies when biopsies are difficult to perform.


Assuntos
Biópsia/métodos , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/patologia , Encéfalo/patologia , Imageamento por Ressonância Magnética/métodos , Nanoconjugados , Nanomedicina/métodos , Animais , Sequência de Bases , Barreira Hematoencefálica/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Diagnóstico Diferencial , Receptores ErbB/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Nanoconjugados/química , Metástase Neoplásica , Oligonucleotídeos Antissenso/química , Oligonucleotídeos Antissenso/genética , Oligonucleotídeos Antissenso/metabolismo , Receptor ErbB-2/metabolismo , Análise de Sobrevida
19.
Int J Mol Sci ; 16(4): 8607-20, 2015 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-25894227

RESUMO

Multifunctional polymer nanoconjugates containing multiple components show great promise in cancer therapy, but in most cases complete analysis of each component is difficult. Polymalic acid (PMLA) based nanoconjugates have demonstrated successful brain and breast cancer treatment. They consist of multiple components including targeting antibodies, Morpholino antisense oligonucleotides (AONs), and endosome escape moieties. The component analysis of PMLA nanoconjugates is extremely difficult using conventional spectrometry and HPLC method. Taking advantage of the nature of polyester of PMLA, which can be cleaved by ammonium hydroxide, we describe a method to analyze the content of antibody and AON within nanoconjugates simultaneously using SEC-HPLC by selectively cleaving the PMLA backbone. The selected cleavage conditions only degrade PMLA without affecting the integrity and biological activity of the antibody. Although the amount of antibody could also be determined using the bicinchoninic acid (BCA) method, our selective cleavage method gives more reliable results and is more powerful. Our approach provides a new direction for the component analysis of polymer nanoconjugates and nanoparticles.


Assuntos
Malatos/química , Nanoconjugados/química , Polímeros/química , Antineoplásicos/química , Sistemas de Liberação de Medicamentos , Cinética , Trastuzumab/química
20.
Bangk Med J ; 10: 83-97, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29142857

RESUMO

Professor Black and colleagues have been working to improve the quality and sensitivity of imaging in the early detection of conditions from brain tumors to Alzheimer's disease to enhance treatment protocols and patient management. Professor Black et al introduced nanoparticles to improve MRI imaging. These nanoparticles consist of poly (b-L- malic acid (PMLA)) conjugates with monoclonal antibodies ((mAbs)) and Gd-DOTA. These are known as MRI nano-imaging agents (NIA). Most importantly, they can penetrate the endothelial blood-brain barrier (BBB) to reach brain tumors (primary or metastasis). This is effective in cases of brain tumors or breast cancer or other cancers such as lung cancer and gastric cancer having HER2 and/or EGFR positive crossing BBB. By the covalent conjugation of MR contrast (NIA), the MRI virtual biopsy can differentiate brain tumors from infections or other brain pathological conditions. The brain's intrinsic natural fluorescence such as NADH, FAD, lipopigments and porphyrin in the brain tissue can be identified by using time resolved fluorescence spectroscopy (TRFS) which is operated through the use of ultra-short laser. TRFS produces various color bands to differentiate the tumor from normal brain tissue in real time and registers the data on a 3D map. This is significant, as this will provide a greatly improved assessment methodology of tissue type. Consequently, this will potentially result in shorter operation times as well as more satisfactory tumor removal. In the detection of Alzheimer disease, amyloid plaque is deposited in retina tissue (including the RGC, RNFL and inner plexiform layer) which can produce a fluorescence effect by using curcumin as a contrast. This is then shown by human retina amyloid imaging device. Immunotherapies with glatiramer acetate (GA) have been shown to reduce amyloid deposits in brain and retinal AB deposits in mice. The study of advanced imaging technology and techniques including NIA, TRFS and the detection of amyloid plaque in Alzheimer disease are very important approaches to create a new era for diagnostic and therapeutic management of brain tumors and other cancers (HER2 and/or EGFR positive). This pioneering work by Professor Black, and colleagues, gives rise to a new hope for cancer patients for targeted therapy and for immunotherapies in Alzheimer's disease.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA