RESUMO
Challenges for glioma treatment with nanomedicines include physio-anatomical barriers (the blood-brain barrier and blood-brain tumor barrier), low drug loading capacity, and limited circulation time. Here, a red blood cell membrane-coated docetaxel drug nanocrystal (pV-RBCm-NC(DTX)), modified with pHA-VAP (pV) for all-stage targeting of glioma, was designed. The NC(DTX) core exhibited a high drug loading capacity but low in vivo stability, and the RBCm coating significantly enhanced the stability and prolonged in vivo circulation. Moreover, the Y-shaped targeting ligand pV was modified by a mild avidin-biotin interaction, which endowed RBCm-NC(DTX) with superior barrier-crossing ability and therapeutic efficacy. The integration of nanocrystal technology, cell membrane coating, and the avidin-biotin insertion method into this active targeting biomimetic formulation represents a promising drug delivery strategy for glioma.
Assuntos
Antineoplásicos , Neoplasias Encefálicas , Docetaxel , Membrana Eritrocítica , Glioma , Nanopartículas , Docetaxel/administração & dosagem , Docetaxel/farmacocinética , Docetaxel/química , Glioma/tratamento farmacológico , Animais , Nanopartículas/química , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Membrana Eritrocítica/efeitos dos fármacos , Membrana Eritrocítica/química , Linhagem Celular Tumoral , Neoplasias Encefálicas/tratamento farmacológico , Masculino , Sistemas de Liberação de Medicamentos , Avidina/administração & dosagem , Avidina/química , Humanos , Biotina/química , Biotina/administração & dosagem , Ratos Sprague-Dawley , Barreira Hematoencefálica/metabolismo , Camundongos Endogâmicos BALB C , Camundongos NusRESUMO
Low back pain is often the direct result of degeneration of the intervertebral disc. A wide range of therapeutics including anti-catabolic, pro-anabolic factors and chemo-attractants that can stimulate resident cells and recruit endogenous progenitors are under consideration. The avascular nature and the dense matrix of this tissue make it challenging for systemically administered drugs to reach their target cells inside the nucleus pulposus (NP), the central gelatinous region of the intervertebral disc (IVD). Therefore, local intra-discal injection of therapeutic drugs directly into the NP is a clinically relevant delivery approach, however, suffers from rapid and wide diffusion outside the injection site resulting in short lived benefits while causing systemic toxicity. NP has a high negative fixed charge density due to the presence of negatively charged aggrecan glycosaminoglycans that provide swelling pressures, compressive stiffness and hydration to the tissue. This negative fixed charge density can also be used for enhancing intra-NP residence time of therapeutic drugs. Here we design positively charged Avidin grafted branched Dextran nanostructures that utilize long-range binding effects of electrostatic interactions to bind with the intra-NP negatively charged groups. The binding is strong enough to enable a month-long retention of cationic nanostructures within the NP following intra-discal administration, yet weak and reversible to allow movement to reach cells dispersed throughout the tissue. The branched carrier has multiple sites for drug conjugation and can reduce the need for multiple injections of high drug doses and minimize associated side-effects, paving the way for effective clinical translation of potential therapeutics for treatment of low back pain and disc degeneration.
Assuntos
Avidina/administração & dosagem , Dextranos/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Disco Intervertebral/efeitos dos fármacos , Nanoestruturas/administração & dosagem , Animais , Avidina/farmacologia , Bovinos , Dextranos/farmacologia , Glicosaminoglicanos , Meia-Vida , Injeções , Degeneração do Disco Intervertebral/tratamento farmacológico , Dor Lombar/tratamento farmacológico , Núcleo Pulposo/efeitos dos fármacos , Núcleo Pulposo/metabolismo , Eletricidade EstáticaRESUMO
The lymphatics are a target for a range of therapeutic purposes, including cancer therapy and vaccination, and both vesicle size and charge have been considered as factors controlling lymphatic targeting. Within this work, a range of liposomal formulations were investigated to develop a liposomal lymphatic targeting system. Initial screening of formulations considered the effect of charge, with neutral, cationic and anionic liposomes being investigated. Biodistribution studies demonstrated that after intramuscular injection, anionic liposomes offered the most rapid clearance to the draining lymphatics with cationic liposomes forming a depot at the injection site. Anionic liposomes containing phosphatidylserine showed higher clearance to the lymphatics and this may result form preferential uptake by macrophages. In terms of vesicle size, smaller unilamellar vesicles gave high lymphatic targeting and a 10-fold increase in concentration was achieved in dose escalation studies. Given that effective trafficking to the lymphatics was achieved, the next step was to enhance retention of the liposomes within the lymphatics, therefore the liposome formulation was combined with an avidin/biotin complex mechanism. The affinity of avidin for biotin allows biotinylated liposomes to complex in the presence of avidin. By pre-dosing with avidin, the biotin-avidin complex can be exploited to promote longer retention of the liposomes at the draining lymphatics. To load these small, biotinylated liposomes with protein, microfluidics manufacturing was used. Using microfluidics, protein could easily be incorporated in these small (~90nm) biotinylated liposomes. Both liposome and protein retention at the local draining lymph nodes was demonstrated with the liposome-biotin-avidin system. These results demonstrate that microfluidics can be used to prepare protein-loaded liposomes that offer enhanced lymphatic targeting and retention of both the liposomes and entrapped antigen.
Assuntos
Lipossomos , Vasos Linfáticos/metabolismo , Microfluídica/métodos , Animais , Avidina/administração & dosagem , Biotina/administração & dosagem , Biotinilação , Feminino , Humanos , Lipossomos/administração & dosagem , Lipossomos/química , Lipossomos/farmacocinética , Macrófagos/fisiologia , Camundongos Endogâmicos C57BL , Fagocitose , Fosfatidilserinas/administração & dosagem , Células THP-1 , Distribuição Tecidual , Vacinas/administração & dosagemRESUMO
The overexpression of vascular endothelial growth factor (VEGF) in varying types of solid tumor renders radioimmunotherapy (RIT) with the anti-VEGF antibody bevacizumab (BV) a promising treatment. However, the slow blood clearance of BV, which may increase the occurrence risk of hematotoxicity, hinders the application of BV-RIT. Using the avidin chase is a long-known blood clearance enhancement strategy for biotinylated-mAb. To enhance RIT efficacy by increasing the radioactivity dose, we evaluated the ability of avidin to accelerate the blood clearance of yttrium-90 (90Y)-labeled biotinylated BV (90Y-Bt-BV) in a xenograft mouse model of triple-negative breast cancer (TNBC). The biodistribution study in the TNBC xenograft mice confirmed the high and specific tumor accumulation of the indium-111 (111In)-BV. The blood clearance enhancement effect of the avidin chase was demonstrated in the normal mouse studies with 111In-Bt-BV. In the subsequent biodistribution studies with the tumor-bearing mice, an optimized dose of avidin injection subsequent to 111In-Bt-BV with an appropriate biotin valency successfully accelerated the blood clearance of 111In-Bt-BV without impairing its tumor accumulation level. The avidin chase enabled an increase in the maximum tolerated dose of 90Y-Bt-BV to twice as much as that of 90Y-BV in tumor-bearing mice and thereby significantly improved the therapeutic effect of 90Y-Bt-BV compared to 90Y-BV ( p < 0.05). These results underscored the potential usefulness of 90Y-bevacizumab-RIT with the avidin chase for the treatment of VEGF-positive tumors.
Assuntos
Avidina/administração & dosagem , Bevacizumab/farmacologia , Imunoconjugados/farmacologia , Radioimunoterapia/efeitos adversos , Neoplasias de Mama Triplo Negativas/sangue , Radioisótopos de Ítrio/farmacologia , Animais , Bevacizumab/química , Biotina/química , Linhagem Celular Tumoral , Feminino , Humanos , Imunoconjugados/química , Taxa de Depuração Metabólica/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Camundongos Nus , Radioimunoterapia/métodos , Distribuição Tecidual , Neoplasias de Mama Triplo Negativas/patologia , Neoplasias de Mama Triplo Negativas/radioterapia , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Radioisótopos de Ítrio/químicaRESUMO
Magnetically responsive microbubbles (MagMBs), consisting of an oxygen gas core and a phospholipid coating functionalised with Rose Bengal (RB) and/or 5-fluorouracil (5-FU), were assessed as a delivery vehicle for the targeted treatment of pancreatic cancer using combined antimetabolite and sonodynamic therapy (SDT). MagMBs delivering the combined 5-FU/SDT treatment produced a reduction in cell viability of over 50% when tested against a panel of four pancreatic cancer cell lines in vitro. Intravenous administration of the MagMBs to mice bearing orthotopic human xenograft BxPC-3 tumours yielded a 48.3% reduction in tumour volume relative to an untreated control group (p<0.05) when the tumour was exposed to both external magnetic and ultrasound fields during administration of the MagMBs. In contrast, application of an external ultrasound field alone resulted in a 27% reduction in tumour volume. In addition, activated caspase and BAX protein levels were both observed to be significantly elevated in tumours harvested from animals treated with the MagMBs in the presence of magnetic and ultrasonic fields when compared to expression of those proteins in tumours from either the control or ultrasound field only groups (p<0.05). These results suggest MagMBs have considerable potential as a platform to enable the targeted delivery of combined sonodynamic/antimetabolite therapy in pancreatic cancer.
Assuntos
Antimetabólitos Antineoplásicos/administração & dosagem , Fluoruracila/administração & dosagem , Nanopartículas Metálicas/administração & dosagem , Microbolhas , Sonicação , Animais , Antimetabólitos Antineoplásicos/química , Avidina/administração & dosagem , Avidina/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Compostos Férricos/administração & dosagem , Compostos Férricos/química , Fluoruracila/química , Humanos , Fenômenos Magnéticos , Nanopartículas Metálicas/química , Camundongos SCID , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Rosa Bengala/administração & dosagem , Rosa Bengala/química , Carga Tumoral/efeitos dos fármacosRESUMO
Avidin-biotin interaction is one of the strongest non-covalent interactions in the nature. Avidin and its analogues have therefore been extensively utilized as probes and affinity matrices for a wide variety of applications in biochemical assays, diagnosis, affinity purification, and drug delivery. Recently, there has been a growing interest in exploring this non-covalent interaction in nanoscale drug delivery systems for pharmaceutical agents, including small molecules, proteins, vaccines, monoclonal antibodies, and nucleic acids. Particularly, the ease of fabrication without losing the chemical and biological properties of the coupled moieties makes the avidin-biotin system a versatile platform for nanotechnology. In addition, avidin-based nanoparticles have been investigated as diagnostic systems for various tumors and surface antigens. In this review, we will highlight the various fabrication principles and biomedical applications of avidin-based nanoparticles in drug delivery and diagnosis. The structures and biochemical properties of avidin, biotin and their respective analogues will also be discussed.
Assuntos
Avidina/administração & dosagem , Sistemas de Liberação de Medicamentos , Nanopartículas/administração & dosagem , Animais , Avidina/uso terapêutico , Biotina/administração & dosagem , Humanos , Nanopartículas/uso terapêutico , NanotecnologiaRESUMO
For locally advanced and metastatic head and neck squamous cell carcinoma (HNSCC), the current clinical use of Cetuximab in chemo/radiotherapy protocols is often associated to severe systemic toxicity. Here we report in vitro data in human FaDu pharynx SCC cells, showing that inactive concentrations of biotinylated Cetuximab (bCet) become active upon anchorage to AvidinOX on the surface of tumor cells. AvidinOX-anchored bCet induces apoptosis and DNA damage as well as specific inhibition of signaling, degradation and abrogation of nuclear translocation of EGFR. In the mouse model of FaDu cancer, we show that intra-tumor injection of AvidinOX allows anti-tumor activity of an otherwise inactive, intraperitoneally delivered, low dose bCet. Consistently with in vitro data, in vivo tumor inhibition is associated to induction of apoptosis, DNA damage and reduced angiogenesis. AvidinOX is under clinical investigation for delivering radioactive biotin to inoperable tumors (ClinicalTrials.gov NCT02053324) and present data support its use for the local treatment of HNSCC in combination with systemic administration of low dose bCet.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Carcinoma de Células Escamosas/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Avidina/administração & dosagem , Biotinilação , Carcinoma de Células Escamosas/irrigação sanguínea , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Cetuximab/administração & dosagem , Relação Dose-Resposta a Droga , Receptores ErbB/metabolismo , Feminino , Neoplasias de Cabeça e Pescoço/irrigação sanguínea , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Immunoblotting , Imuno-Histoquímica , Camundongos Nus , Neovascularização Patológica/prevenção & controle , Resultado do Tratamento , Carga Tumoral/efeitos dos fármacosRESUMO
Local treatment of unresectable tumors is challenging, particularly with radioactivity. Current practice relies on external beam irradiation or on a variety of medical devices for brachytherapy. Both approaches proved useful in controlling tumor growth, but are characterized by poor compliance of the patient, significant side-effects, high costs, and technological complexity, which hamper widespread use. The authors recently described a novel form of radionuclide therapy based on the oxidized form of avidin that, chemically reacting with tissue proteins, can secure radioactive biotin within the injected tissue, either when precomplexed or when taken from the blood stream after intravenous administration. AvidinOX-pretargeted (177)Lu-biotinDOTA ((177)Lu-ST2210) is currently under clinical investigation for the treatment of liver oligometastases from colorectal cancer (clinicaltrials.gov/NCT02053324). In the present work, the authors show that injected AvidinOX can link tissues of various natures such as prostate, kidney, breast, or brain and can react by contact with scraped tissues such as skin or urinary bladder. AvidinOX injected into human OSC19 tongue cancer masses orthotopically transplanted in nude mice takes up intravenously administered (90)Y-ST2210, which exerts significant antitumor activity, while preserving the integrity and functionality of the tongue. Present data confirm that AvidinOX-based radionuclide therapy is an innovative and promising approach for the local treatment of inoperable tumors.
Assuntos
Avidina/administração & dosagem , Biotina/análogos & derivados , Compostos Organometálicos/administração & dosagem , Neoplasias da Língua/radioterapia , Radioisótopos de Ítrio/administração & dosagem , Animais , Biotina/administração & dosagem , Cães , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Coelhos , Radioimunoterapia , Suínos , Neoplasias da Língua/patologiaRESUMO
The in vivo utility of technologies employing cell penetrating peptides and bioportides may be compromised by the general capacity of polycationic peptides to activate mast cell secretion. Moreover, the same technologies could be exploited in a clinical setting either to directly modulate intrinsic exocytotic mechanisms or to load mast cells with bioactive cargoes. Comparative investigations identified two cell penetrating vectors, Tat and C105Y, which readily translocate into mast cells without inducing receptor-independent exocytosis. Efficient Tat transduction also enabled the intracellular delivery and accumulation of cargoes within discrete intracellular compartments. A tetramethylrhodamine-Tat conjugate is effectively translocated into the secretory lysosomes of RBL-2H3 cells. In contract, the intracellular delivery of avidin, as a non-covalent complex with a biotinylated Tat vector, is also efficient but the protein is predominantly accumulated outside of secretory lysosomes. Significantly, both cargoes can be subsequently released following mast cell stimulation either by mastoparan, a wasp venom secretagogue, or by the physiological mechanism of antigen-induced aggregation of high affinity IgE receptors. These studies indicate that mast cells could be exploited to direct the delivery of bioactive agents to disease sites as an innovative cell-mediated therapy.
Assuntos
Peptídeos Penetradores de Células/administração & dosagem , Mastócitos/metabolismo , Avidina/administração & dosagem , Degranulação Celular , Linhagem Celular , Exocitose , Humanos , Lisossomos/metabolismo , Rodaminas/administração & dosagemRESUMO
For evaluation of new approaches to drug delivery into cartilage, the choice of an animal model is critically important. Since cartilage thickness varies with animal size, different levels of drug uptake, transport and retention should be expected. Simple intra-articular injection can require very high drug doses to achieve a concentration gradient high enough for drug diffusion into cartilage. New approaches involve nanoparticle delivery of functionalized drugs directly into cartilage; however, diffusion-binding kinetics proceeds as the square of cartilage thickness. In this study, we demonstrate the necessity of using larger animals for sustained intra-cartilage delivery and retention, exemplified by intra-articular injection of Avidin (drug-carrier) into rabbits and compared to rats in vivo. Penetration and retention of Avidin within cartilage is greatly enhanced by electrostatic interactions. Medial tibial cartilage was the thickest of rabbit cartilages, which generated the longest intra-cartilage half-life of Avidin (τ1/2 = 154 h). In contrast, Avidin half-life in thinner rat cartilage was 5-6 times shorter (τ1/2 â¼ 29 h). While a weak correlation (R(2) = 0.43) was found between Avidin half-lives and rabbit tissue GAG concentrations, this correlation improved dramatically (R(2) = 0.96) when normalized to the square of cartilage thickness, consistent with the importance of cartilage thickness to evaluation of drug delivery and retention.
Assuntos
Avidina/farmacocinética , Cartilagem Articular/metabolismo , Sistemas de Liberação de Medicamentos , Animais , Avidina/administração & dosagem , Cartilagem Articular/anatomia & histologia , Feminino , Glicosaminoglicanos/metabolismo , Injeções Intra-Articulares , Modelos Animais , Coelhos , XantenosRESUMO
Intra-articular (i.a.) drug delivery for local treatment of osteoarthritis remains inadequate due to rapid clearance by the vasculature or lymphatics. Local therapy targeting articular cartilage is further complicated by its dense meshwork of collagen and negatively charged proteoglycans, which can prevent even nano-sized solutes from entering. In a previous in vitro study, we showed that Avidin, due to its size (7 nm diameter) and high positive charge (pI 10.5), penetrated the full thickness of bovine cartilage and was retained for 15 days. With the goal of using Avidin as a nano-carrier for cartilage drug delivery, we investigated its transport properties within rat knee joints. Avidin penetrated the full thickness of articular cartilage within 6 h, with a half-life of 29 h, and stayed inside the joint for 7 days after i.a. injection. The highest concentration of Avidin was found in cartilage, the least in patellar tendon and none in the femoral bone; in contrast, negligible Neutravidin (neutral counterpart of Avidin) was present in cartilage after 24 h. A positive correlation between tissue sGAG content and Avidin uptake (R(2) = 0.83) confirmed the effects of electrostatic interactions. Avidin doses up to at least 1 µM did not affect bovine cartilage explant cell viability, matrix catabolism or biosynthesis.
Assuntos
Avidina/administração & dosagem , Cartilagem Articular/metabolismo , Portadores de Fármacos/administração & dosagem , Articulação do Joelho/metabolismo , Animais , Avidina/farmacocinética , Avidina/farmacologia , Cartilagem Articular/efeitos dos fármacos , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Condrócitos/efeitos dos fármacos , Glicosaminoglicanos/metabolismo , Meia-Vida , Injeções Intra-Articulares , Ligamentos/metabolismo , Ratos , Ratos Endogâmicos F344 , Eletricidade Estática , Tendões/metabolismoRESUMO
This study describes the formulation optimization and body-cell distribution and clearance in mice of a dually fluorescent biodegradable poly avidin nanoassembly based on the novel Avidin-Nucleic-Acid-Nano-ASsembly (ANANAS) platform as a potential advancement of classic avidin/biotin-based targeted delivery. The nanoformulation circulates freely in the bloodstream; it is slowly captured by filter organs; it is efficiently cleared within 24-48 h, and it is poorly immunogenic. The system displays more favorable properties than its parent monomeric avidin and it is a promising tool for diagnostic purposes for future translational aims, for which free circulation in the bloodstream, safety, multifunctionality and high composition definition are all necessary requirements. In addition, the assembly shows a time-dependent cell penetration capability, suggesting it may also function as a NP-dependent drug delivery tool. The ease of preparation together with the possibility to fine-tune the surface composition makes it also an ideal candidate to understand if and how nanoparticle composition affects its localization.
Assuntos
Avidina/administração & dosagem , Nanopartículas , Ácidos Nucleicos/química , Animais , CamundongosRESUMO
Local drug delivery into cartilage remains a challenge due to its dense extracellular matrix of negatively charged proteoglycans enmeshed within a collagen fibril network. The high negative fixed charge density of cartilage offers the unique opportunity to utilize electrostatic interactions to augment transport, binding and retention of drug carriers. With the goal of developing particle-based drug delivery mechanisms for treating post-traumatic osteoarthritis, our objectives were, first, to determine the size range of a variety of solutes that could penetrate and diffuse through normal cartilage and enzymatically treated cartilage to mimic early stages of OA, and second, to investigate the effects of electrostatic interactions on particle partitioning, uptake and binding within cartilage using the highly positively charged protein, Avidin, as a model. Results showed that solutes having a hydrodynamic diameter ≤10 nm can penetrate into the full thickness of cartilage explants while larger sized solutes were trapped in the tissue's superficial zone. Avidin had a 400-fold higher uptake than its neutral same-sized counterpart, NeutrAvidin, and >90% of the absorbed Avidin remained within cartilage explants for at least 15 days. We report reversible, weak binding (K(D) ~ 150 µM) of Avidin to intratissue sites in cartilage. The large effective binding site density (N(T) ~ 2920 µM) within cartilage matrix facilitates Avidin's retention, making its structure suitable for particle based drug delivery into cartilage.
Assuntos
Avidina/administração & dosagem , Cartilagem Articular/metabolismo , Sistemas de Liberação de Medicamentos , Modelos Biológicos , Osteoartrite/tratamento farmacológico , Ferimentos e Lesões/complicações , Animais , Avidina/farmacocinética , Bovinos , Glicosaminoglicanos/metabolismo , Microscopia Confocal , Estrutura Molecular , Osteoartrite/etiologia , Propriedades de SuperfícieRESUMO
Gene therapy offers a bright future for the treatment of cancers. One of the research highlights focuses on smart gene delivery vectors with good biocompatibility and tumor-targeting ability. Here, a novel gene vector self-assembled through avidin-biotin interaction with optimized targeting functionality, biotinylated tumor-targeting peptide/avidin/biotinylated cell-penetrating peptide (TAC), was designed and prepared to mediate the in vitro and in vivo delivery of p53 gene. TAC exhibited efficient DNA-binding ability and low cytotoxicity. In in vitro transfection assay, TAC/p53 complexes showed higher transfection efficiency and expression amount of p53 protein in MCF-7 cells as compared with 293T and HeLa cells, primarily due to the specific recognition between tumor-targeting peptides and receptors on MCF-7 cells. Additionally, by in situ administration of TAC/p53 complexes into tumor-bearing mice, the expression of p53 gene was obviously upregulated in tumor cells, and the tumor growth was significantly suppressed. This study provides an alternative and unique strategy to assemble functionalized peptides, and the novel self-assembled vector TAC developed is a promising gene vector for cancer therapy.
Assuntos
Avidina/genética , Avidina/metabolismo , Biotina/genética , Biotina/metabolismo , Terapia Genética/métodos , Vetores Genéticos/genética , Animais , Avidina/administração & dosagem , Biotina/administração & dosagem , Biotinilação , Linhagem Celular Tumoral , Peptídeos Penetradores de Células/genética , Peptídeos Penetradores de Células/metabolismo , DNA/genética , Técnicas de Transferência de Genes , Genes p53 , Vetores Genéticos/administração & dosagem , Vetores Genéticos/metabolismo , Células HEK293 , Células HeLa , Humanos , Células MCF-7 , Masculino , Camundongos , Neoplasias/genética , Neoplasias/terapia , Peptídeos/genética , Peptídeos/metabolismo , Transfecção/métodosRESUMO
In this study, avidin-biotin technology was combined with a multifunctional drug carrier modality i.e. liposomes to achieve an active and versatile targeting approach. The anti-cancer drug doxorubicin (DOX) was modified with direct biotinylation (B-DOX) (Allart et al., 2003), or encapsulated in biotinylated sterically stabilized pH-sensitive liposomes (BL-DOX), and targeted to the lentiviral vector transduced cells expressing an avidin fusion protein on the cell membrane (Lehtolainen et al., 2003; Lesch et al., 2009). The direct biotinylation of doxorubicin improved cell internalization in rat glioma (BT4C) cells expressing avidin fusion protein receptor but cell toxicity was reduced by 78-fold due to impaired nuclear localization. In contrast, liposomal formulations restored the biological activity of the DOX in several cell lines. However, mainly due to uptake via non-specific pathways the active targeting of BL-DOX was negligible in both in vitro and in vivo studies. Active targeting with multifunctional drug carrier systems is challenging and further studies will be needed to optimize the properties of targeted drug carrier and receptor expression systems.
Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Avidina/administração & dosagem , Biotina/administração & dosagem , Doxorrubicina/administração & dosagem , Animais , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacocinética , Avidina/genética , Biotina/genética , Biotinilação , Linhagem Celular Tumoral , Doxorrubicina/química , Doxorrubicina/farmacocinética , Humanos , Cinética , Lipossomos , Camundongos , Camundongos Nus , Ratos , Proteínas Recombinantes de Fusão/administração & dosagem , Distribuição TecidualRESUMO
PURPOSE: Intraoperative Avidination for Radionuclide Therapy (IART) is a novel targeted radionuclide therapy recently used in patients with early breast cancer. It is a radionuclide approach with (90)Y-biotin combined with external beam radiotherapy (EBRT) to release a boost of radiation in the tumour bed. Two previous clinical trials using dosimetry based on the calculation of mean absorbed dose values with the hypothesis of uniform activity distribution (MIRD 16 method) assessed the feasibility and safety of IART. In the present retrospective study, a voxel dosimetry analysis was performed to investigate heterogeneity in distribution of the absorbed dose. The aim of this work was to compare dosimetric and radiobiological evaluations derived from average absorbed dose vs. voxel absorbed dose approaches. METHODS: We evaluated 14 patients who were injected with avidin into the tumour bed after conservative surgery and 1 day later received an intravenous injection of 3.7 GBq of (90)Y-biotin (together with 185 MBq (111)In-biotin for imaging). Sequential images were used to estimate the absorbed dose in the target region according to the standard dosimetry method (SDM) and the voxel dosimetry method (VDM). The biologically effective dose (BED) distribution was also evaluated. Dose/volume and BED volume histograms were generated to derive equivalent uniform BED (EUBED) and equivalent uniform dose (EUD) values. RESULTS: No "cold spots" were highlighted by voxel dosimetry. The median absorbed-dose in the target region was 20 Gy (range 15-27 Gy) by SDM, and the median EUD was 20.4 Gy (range 16.5-29.4 Gy) by the VDM; SDM and VDM estimates differed by about 6 %. The EUD/mean voxel absorbed dose ratio was >0.9 in all patients, indicative of acceptable uniformity in the target. The median BED and EUBED values were 21.8 Gy (range 15.9-29.3 Gy) and 22.8 Gy (range 17.3-31.8 Gy), respectively. CONCLUSION: VDM highlighted the absence of significant heterogeneity in absorbed dose in the target. The EUD/mean absorbed dose ratio indicated a biological efficacy comparable to that of uniform distribution of absorbed dose. The VDM is recommended for improving accuracy, taking into account actual activity distribution in the target region. The radiobiological model applied allowed us to compare the effects of IART® with those of EBRT and to match the two irradiation modalities.
Assuntos
Biotina/análogos & derivados , Neoplasias da Mama/radioterapia , Compostos Organometálicos/farmacocinética , Radiometria/métodos , Compostos Radiofarmacêuticos/farmacocinética , Avidina/administração & dosagem , Biotina/farmacocinética , Biotina/uso terapêutico , Feminino , Humanos , Imagem Multimodal , Compostos Organometálicos/uso terapêutico , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos/uso terapêutico , Tomografia Computadorizada por Raios X , Radioisótopos de Ítrio/farmacocinética , Radioisótopos de Ítrio/uso terapêuticoRESUMO
The objective of this 49-d experiment was to test effects of cecal oxytetracycline (OTC) infusion, and dietary avidin and biotin supplementation on the biotin status of nongravid gilts. Twenty-eight crossbred gilts with an initial age of 160 d and BW of 120 kg were surgically fitted with a T-cannula in the terminal ileum, a cecal fistula, and an indwelling catheter in the anterior vena cava, and allotted to 7 dietary treatments. Treatments with the basal semipurified (SP) diet fed at 1.86 kg/d were: SP-1, negative control; SP-2, positive control with 270 µg of biotin/kg; SP-3, with spray-dried egg albumen (EA, 100 g/d) and OTC (2.56 g/d by cecal infusion); and SP-4, with EA, OTC, and 700 µg of biotin/kg. Treatments with the basal corn-soybean meal (CS) diet fed at 1.80 kg/d were: CS-1, negative control; CS-2, with EA and OTC; and CS-3, with EA, OTC, and 700 µg of biotin/kg. Response criteria were: fecal bacteria counts; plasma concentrations of biotin, glucose, and urea N (PUN); liver pyruvate carboxylase (PC) activity; kidney and epithelial tissue histology; ileal and fecal biotin concentrations; ileal and total tract N and energy utilization; daily gilt observation; and BW gain. Blood samples were collected every 7 d with serial samples collected on d 49. Total urine collections and fecal grab samples were made twice daily from d 44 to 49. Gilts were killed on d 50 and liver, kidney, and skin samples were collected. No gilts had symptoms of biotin deficiency. There were no treatment differences in BW gain, plasma glucose concentrations, liver PC activity, kidney and epithelial tissue histology, or fecal bacteria counts. Ileal and total tract N and energy digestibilities (%) did not differ among treatments within the same protein source, with greater (P ≤ 0.05) values for gilts on the SP treatments than the CS treatments. However, N retained/N absorbed and N retained/N intake (%) were less (P ≤ 0.05) and PUN concentrations were greater (P ≤ 0.05) for SP treatments with cecal OTC infusion. The overall fecal biotin concentration mean was 2.6-fold greater than the overall ileal biotin concentration mean. In conclusion, no gilts in the current experiment became biotin deficient because the biotin requirements were met primarily by microbial synthesis and absorption of biotin from the distal small intestine and large intestine, with corn and soybean meal contributing endogenous biotin. Therefore, supplementation of diets for gilts entering the breeding herd with 100% of the current NRC biotin requirement for sows is adequate.
Assuntos
Avidina/farmacologia , Biotina/farmacologia , Oxitetraciclina/farmacologia , Suínos/metabolismo , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Avidina/administração & dosagem , Bactérias/classificação , Bactérias/isolamento & purificação , Biotina/administração & dosagem , Ceco/efeitos dos fármacos , Ceco/microbiologia , Dieta/veterinária , Suplementos Nutricionais , Fezes/microbiologia , Feminino , Oxitetraciclina/administração & dosagem , Suínos/sangueRESUMO
Biotinylated Pluronic F127/poly(lactic acid) block copolymers (B-F127-PLA) were successfully synthesized previously by our group. In the present study, the release behaviors of paclitaxel-loaded B-F127-PLA nanoparticles and their targeting properties to human ovarian carcinoma cells were investigated. Paclitaxel (pac) loaded in B-F127-PLA nanoparticles shows an initial burst release in the first 6h and followed by a slow release. The in vitro targeting behaviors of B-F127-PLA nanoparticles against human ovarian cancer cells (OVCAR-3, SKOV-3) were investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) tests and fluorescence microscopy (FM) technique. Targeting was based on a three-step biotin-avidin targeting approach using biotinylated anti-CA125 antibody specific for the CA-125 antigen that is highly expressed on OVCAR-3 cells but not expressed on SKOV-3 cells. MTT results show that the anticancer effect of paclitaxel in B-F127-PLA nanoparticles over OVCAR-3 cells was stronger than that over SKOV-3 cells, indicating that B-F127-PLA nanoparticles were delivered more effectively to OVCAR-3 cells than to SKOV-3 cells. The targeting behaviors of B-F127-PLA nanoparticles were further confirmed by FM technique. The intracellular distribution of B-F127-PLA nanoparticles was also studied using a triple-labeling method. It was observed that B-F127-PLA nanoparticles are mainly localized within the cytoplasm of OVCAR-3 cells. The in vivo antitumor efficacy of pac-loaded B-F127-PLA nanoparticles by three-step method as measured by change in tumor volume of OVCAR-3 implanted in Balb/C nude mice was greater than that by one-step method.
Assuntos
Anticorpos Monoclonais/metabolismo , Antineoplásicos Fitogênicos/metabolismo , Avidina/metabolismo , Antígeno Ca-125/imunologia , Portadores de Fármacos , Nanopartículas , Neoplasias Ovarianas/metabolismo , Paclitaxel/metabolismo , Poloxâmero/química , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/química , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Avidina/administração & dosagem , Biotinilação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Química Farmacêutica , Feminino , Humanos , Injeções Intraperitoneais , Cinética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Microscopia de Fluorescência , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/patologia , Paclitaxel/administração & dosagem , Paclitaxel/química , Paclitaxel/farmacologia , Solubilidade , Tecnologia Farmacêutica/métodos , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
AvidinOX™, a product containing aldehyde groups, generated by ligand-assisted sugar oxidation of avidin by sodium periodate, maintains the capacity to bind biotin with very high affinity and exhibits the property to chemically link cellular and tissue proteins through Schiff's base formation thus residing in tissues for weeks. In recent studies, we have shown that AvidinOX exhibits much higher persistency in the skeletal muscle than native avidin. The aim of the present study is to evaluate whether AvidinOX-biotin interaction might be exploited to target biotinylated cells to an AvidinOX pre-treated muscle. To accomplish this we performed the following experiments: 1) The proliferation and differentiation properties of biotinylated C2C12 myoblasts were tested in vitro upon linkage to AvidinOX; 2) Bone marrow-derived cells (BMDC) were isolated from GFP positive transgenic mice [strain C57 BL/6-tg (UBC-GFP)] and after biotinylation (bBMDC) were intravenously administered to naive and MAVA+ (Mouse anti Avidin Antibody) C57/B6 mice previously injected with AvidinOX in a tibial muscle (TM). Localization efficiency of GFP+ bBMDC was evaluated on serial sections of the AvidinOX- and vehicle-treated (contra lateral limb) TM, 5 days after transplantation. Results show that biotinylated C2C12 cells, once linked to AvidinOX, maintain their proliferation and differentiation capacity, in vitro. Intravenous injection of biotinylated GFP+ bone marrow-derived cells leads to their specific and efficient localization in the AvidinOX-pre-treated, but not contra lateral muscle of both naive and MAVA+ mice. The present data suggest a potential use of AvidinOX to improve tissue targeted delivery of biotinylated cells.
Assuntos
Avidina/metabolismo , Biotinilação , Transplante de Células-Tronco , Animais , Avidina/administração & dosagem , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Sistemas de Liberação de Medicamentos , Feminino , Imunofluorescência , Camundongos , Camundongos Endogâmicos C57BLRESUMO
As an alternative to directly targeting of necrotic tissue using hypericin, we synthesized a conjugate of hypericin to biotin for use in a pretargeting approach. With this conjugate, we explored the possibility of a two-step pretargeting strategy using (123)I-labeled avidin as effector molecule directed against necrotic RIF-1 tumors. Hypericin was conjugated to biotin-ethylenediamine in a straightforward coupling method using n-hydroxysuccinimide and dicyclohexylcarbodiimide. The necrosis avidity of the conjugate was first confirmed in necrotic liver tissue by means of fluorescence microscopy. Using autoradiography imaging and whole body-biodistribution, the accumulation of (123)I-avidin in necrotic tumor tissue was evaluated 24 h after administration and 48 h after pretargeting with hypericin-biotin. Analysis of autoradiography images show a higher accumulation of (123)I-avidin in pretargeted compared to nontargeted tissue. However, absolute accumulation of (123)I-avidin in necrotic tumors was low as shown by biodistribution experiments. Direct injection of hypericin-biotin or biotin-fluorescein did not substantially improve (123)I-avidin accumulation after pretargeting, pointing towards a poor penetration of avidin in necrotic tissue. Our results show the feasibility of a pretargeting technique using a small molecule as targeting agent. However, for a more efficient accumulation of the effector molecule in necrotic tissue, other pretargeting strategies need to be investigated.