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1.
Antimicrob Agents Chemother ; 67(6): e0170922, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37154745

RESUMO

Atovaquone-proguanil (AP) is used as treatment for uncomplicated malaria, and as a chemoprophylactic agent against Plasmodium falciparum. Imported malaria remains one of the top causes of fever in Canadian returning travelers. Twelve sequential whole-blood samples before and after AP treatment failure were obtained from a patient diagnosed with P. falciparum malaria upon their return from Uganda and Sudan. Ultradeep sequencing was performed on the cytb, dhfr, and dhps markers of treatment resistance before and during the episode of recrudescence. Haplotyping profiles were generated using three different approaches: msp2-3D7 agarose and capillary electrophoresis, and cpmp using amplicon deep sequencing (ADS). A complexity of infection (COI) analysis was conducted. De novo cytb Y268C mutants strains were observed during an episode of recrudescence 17 days and 16 h after the initial malaria diagnosis and AP treatment initiation. No Y268C mutant reads were observed in any of the samples prior to the recrudescence. SNPs in the dhfr and dhps genes were observed upon initial presentation. The haplotyping profiles suggest multiple clones mutating under AP selection pressure (COI > 3). Significant differences in COI were observed by capillary electrophoresis and ADS compared to the agarose gel results. ADS using cpmp revealed the lowest haplotype variation across the longitudinal analysis. Our findings highlight the value of ultra-deep sequencing methods in the understanding of P. falciparum haplotype infection dynamics. Longitudinal samples should be analyzed in genotyping studies to increase the analytical sensitivity.


Assuntos
Antimaláricos , Malária Falciparum , Humanos , Plasmodium falciparum/genética , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Sefarose/uso terapêutico , Canadá , Proguanil/farmacologia , Proguanil/uso terapêutico , Atovaquona/farmacologia , Atovaquona/uso terapêutico , Malária Falciparum/prevenção & controle , Combinação de Medicamentos , Falha de Tratamento , Tetra-Hidrofolato Desidrogenase , Sequenciamento de Nucleotídeos em Larga Escala , Recidiva
2.
BMC Med ; 20(1): 257, 2022 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-35999600

RESUMO

BACKGROUND: Gastrointestinal stromal tumor (GIST) is a rare type of cancer that occurs in the gastrointestinal tract. The majority of GIST cases carry oncogenic forms of KIT, the receptor for stem cell factor (SCF). Small molecule kinase inhibitor imatinib is effective in prolonging the survival of GIST patients by targeting KIT. However, drug resistance often develops during the therapeutic treatment. Here, we produced a SCF-emtansine drug conjugate (SCF-DM1) with favorable drug efficacy towards GIST cells. METHODS: Recombinant human SCF (rhSCF) was expressed in E. coli cells and further purified with Ni-NTA Sepharose and Phenyl Sepharose. It was then conjugated with DM1, and the conjugated product SCF-DM1 was evaluated using in vitro cell-based assays and in vivo xenograft mouse model. RESULTS: SCF-DM1 was effective in inhibiting imatinib-sensitive and -resistant GIST cell lines and primary tumor cells, with IC50 values of < 30 nM. It induced apoptosis and cell cycle arrest in GIST cells. In xenograft mouse model, SCF-DM1 showed favorable efficacy and safety profiles. CONCLUSIONS: rhSCF is a convenient and effective vector for drug delivery to KIT positive GIST cells. SCF-DM1 is an effective drug candidate to treat imatinib-sensitive and -resistant GIST.


Assuntos
Antineoplásicos , Tumores do Estroma Gastrointestinal , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos , Escherichia coli , Tumores do Estroma Gastrointestinal/tratamento farmacológico , Humanos , Mesilato de Imatinib/farmacologia , Mesilato de Imatinib/uso terapêutico , Camundongos , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Proto-Oncogênicas c-kit/metabolismo , Sefarose/farmacologia , Sefarose/uso terapêutico
3.
Int J Biol Macromol ; 208: 20-28, 2022 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-35259437

RESUMO

In this article we report a novel Ag NPs fabricated chitosan-agarose composite functionalized core-shell type Fe3O4 nanoparticle (Ag/CS-Agar@Fe3O4). The biogenic material was analyzed over a number of physicochemical methods like, FT-IR, FE-SEM, TEM, EDX, XRD, VSM and ICP-OES. In catalytic exploration we aimed the synthesis of diverse 2H-indazolo0-b]phthalazine-trione derivatives via one-pot three component coupling of phathalalhydrazide, dimedone and different aldehydes. It afforded good to excellent yields under solvent-less conditions. Robustness of the catalyst was justified by catalyst recyclability for consecutive 10 times, hot filtration and leaching tests. Again, biological activity of the material was evaluated by studying the antioxidant and cytotoxicity properties over lung and liver cancer cell lines. Antioxidant potential of Ag/CS-Agar@Fe3O4 was assessed by DPPH radical scavenging studies and the corresponding IC50 was found to be 96.57 µg/mL. Liver and lung cancer studies over Ag/CS-Agar@Fe3O4 was carried out by MTT assay against HepG2 and A549 cell lines. The corresponding IC50 values were found as 192.35 and 365.28 µg/mL respectively. % Cell viability of the nanomaterial decreased dose dependently over both the cell lines without any cytotoxicity on normal cell line. The results demonstrates Ag/CS-Agar@Fe3O4 nanocomposite to be an efficient chemotherapeutic drug against the lung and hepatocellular carcinoma cells.


Assuntos
Quitosana , Neoplasias Pulmonares , Nanopartículas de Magnetita , Nanocompostos , Ágar , Antioxidantes/uso terapêutico , Catálise , Quitosana/química , Humanos , Fígado , Pulmão , Neoplasias Pulmonares/tratamento farmacológico , Nanopartículas de Magnetita/química , Nanocompostos/química , Ftalazinas/farmacologia , Sefarose/uso terapêutico , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Molecules ; 24(23)2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31775255

RESUMO

Seaweeds are some of the largest producers of biomass in the marine environment and are rich in bioactive compounds that are often used for human and animal health. Porphyran and carrageenan are natural compounds derived from red seaweeds. The former is a characteristic polysaccharide of Porphyra, while the latter is well known from Chondrus, Gigartina, and various Eucheuma species, all in Rhodophyceae. The two polysaccharides have been found to have anti-cancer activity by improving immunity and targeting key apoptotic molecules and therefore deemed as potential chemotherapeutic or chemopreventive agents. This review attempts to review the current study of anti-cancer activity and the possible mechanisms of porphyran and carrageenan derived from red seaweeds to various cancers, and their cooperative actions with other anti-cancer chemotherapeutic agents is also discussed.


Assuntos
Carragenina/uso terapêutico , Neoplasias/tratamento farmacológico , Alga Marinha/química , Sefarose/análogos & derivados , Carragenina/química , Humanos , Imunidade/efeitos dos fármacos , Neoplasias/imunologia , Polissacarídeos/química , Sefarose/química , Sefarose/uso terapêutico
5.
Mar Drugs ; 16(3)2018 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-29509717

RESUMO

Parkinson's disease (PD) is a neurodegenerative movement disorder that is caused by a selective loss of dopaminergic neurons. Current PD treatments provide symptomatic relief but do not prevent or decelerate disease progression. Previous studies have suggested that acetylated and phosphorylated porphyran, derived from Porphyra, produces a neuroprotective effect against 6-OHDA-induced damage. Due to its antioxidant and neuroprotective potential, this study evaluates whether oligo-porphyran (OP) could be beneficial in an experimental model of PD in mice. The drug 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was intraperitoneally injected (20 mg/kg body weight) for seven days to simulate PD, followed by OP administration. We found that the behavioral deficits in spontaneous motor activity, latency to descend in a pole test, and suspension in a traction test were ameliorated, and excessive dopamine (DA) metabolism was suppressed after OP treatment. Additionally, we found that OP protected dopaminergic neurons by preventing MPTP-induced decreases in dopaminergic transporter and tyrosine hydroxylase protein levels. We speculated whether OP regulates a signaling pathway that affects the behavioral changes seen in PD mice. In this study, the PI3K/Akt/Bcl-2 pathway was detected. Our results demonstrate that OP increased the phosphorylation of PI3K/Akt/GSK-3ß and inhibited the activation of caspase-3 and poly (ADP-ribose) polymerase, with changes in the Bax/Bcl-2 ratio. These results showed that OP might promote DA neuron survival in vivo by regulating the PI3K/Akt/Bcl-2 pathway, thereby ameliorating the neurobehavioral deficits in a PD mouse model and suggesting OP as a neuroprotective treatment for PD.


Assuntos
Intoxicação por MPTP/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Porphyra/química , Sefarose/análogos & derivados , Transdução de Sinais/efeitos dos fármacos , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Encéfalo/citologia , Encéfalo/patologia , Modelos Animais de Doenças , Dopamina/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Humanos , Intoxicação por MPTP/induzido quimicamente , Intoxicação por MPTP/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fármacos Neuroprotetores/uso terapêutico , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Sefarose/farmacologia , Sefarose/uso terapêutico
6.
Phytother Res ; 32(3): 452-458, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29226489

RESUMO

Safe and efficient therapeutic agents for bone diseases are required in natural sources. We previously found that edible seaweed-derived polysaccharide porphyran exhibited anti-inflammatory effects through the down regulation of nuclear factor-κB. The aim of this study was to investigate the availability of porphyran as a therapeutic agent for bone diseases. The effects of porphyran on receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclastogenesis in RAW264.7 cells were examined. Porphyran suppressed RANKL-induced osteoclast formation in a concentration-dependent manner (6.25-50 µg/ml) without any cytotoxic effects. Furthermore, real-time polymerase chain reaction analyses indicated that porphyran at 50 µg/ml significantly attenuated the RANKL-induced increase in the mRNA levels of osteoclastogenesis-related marker genes such as nuclear factor of activated T cells, tartrate-resistant acid phosphatase, cathepsin K, and matrix metalloproteinase-9 in RAW264.7 cells. To our knowledge, this is the first report showing that edible-seaweed-derived polysaccharide porphyran can suppress RANKL-induced osteoclastogenesis. Our results suggest that porphyran can be used as a safe therapeutic agent to improve osteoclast-related pathological conditions.


Assuntos
Osteoclastos/metabolismo , Ligante RANK/uso terapêutico , Células RAW 264.7/metabolismo , Sefarose/análogos & derivados , Animais , Diferenciação Celular , Camundongos , Ligante RANK/farmacologia , Sefarose/farmacologia , Sefarose/uso terapêutico
7.
Int J Biol Macromol ; 93(Pt A): 1273-1278, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27693746

RESUMO

Porphyran, a sulfated polysaccharide, isolated from discolored nori (Porphyra yezoensis) (dc-porphyran) and one fraction (F1) purified from dc-porphyran by DEAE-chromatography showed the protective effects on LPS-induced endotoxin shock in mice. Intraperitoneal (i.p.) treatment with dc-porphyran or F1 (100mg/kg) 60min prior to i.p. injection of LPS (30mg/kg) completely protected mice from LPS lethality. At 10mg/kg concentration, F1 demonstrated more protection than dc-porphyran. Intravenous (i.v.) challenge of LPS, even at 20mg/kg, was more lethal than i.p. administration; i.v. injection of F1 (100mg/kg) with LPS significantly improved the survival rate. However, i.v. dc-porphyran (100mg/kg) produced an even lower survival rate than that of LPS alone. We examined pro-inflammatory mediators such as NO and TNF-α in serum. F1 significantly reduced the levels of these markers. Additionally, F1 significantly decreased the malondialdehyde level in the liver, a marker of oxidative stress, while dc-porphyran had almost no effect. Furthermore, F1 significantly decreased the production of TNF-α and NO in peritoneal exudate cells harvested from LPS-challenged mice, while dc-porphyran treatment showed a lesser decrease. Our results suggest that porphyran isolated from discolored nori, especially F1, is capable of suppressing LPS-induced endotoxin shock in vivo.


Assuntos
Lipopolissacarídeos/toxicidade , Porphyra/química , Sefarose/análogos & derivados , Choque Séptico/induzido quimicamente , Choque Séptico/tratamento farmacológico , Animais , Cor , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Óxido Nítrico/biossíntese , Estresse Oxidativo/efeitos dos fármacos , Sefarose/isolamento & purificação , Sefarose/farmacologia , Sefarose/uso terapêutico , Choque Séptico/metabolismo , Fator de Necrose Tumoral alfa/biossíntese
8.
Biomed Mater ; 11(1): 015015, 2016 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-26894556

RESUMO

The use of mucoperiostial flaps during cleft palate surgery is associated with altered palatal bone growth and development. We analyzed the potential usefulness of a bioengineered oral mucosa in an in vivo model of cleft palate. First, a 4 mm palate defect was created in one side of the palate oral mucosa of 3 week-old New Zealand rabbits, and a complete autologous bioengineered oral mucosa (BOM) or acellular fibrin-agarose scaffold (AS) was implanted. No material was implanted in the negative controls (NC), and positive controls were not subjected to palatal defect (PC). Animals were allowed to grow for 6 months and the results were analyzed morphologically (palate mucosa and bone size) and histologically. Results show that palatal mucosa and bone growth and development were significantly altered in NC and AS animals, whereas BOM animals had similar results to PC and the bioengineered oral mucosa was properly integrated in the host palate. The amount and compaction of collagen fibers was similar between BOM and PC, and both groups of animals had comparable contents of proteoglycans and glycoproteins at the palate bone. No differences were found for decorin, osteocalcin and BMP2. The use of bioengineered oral mucosa substitutes is able to improve palate growth and maturation by preventing the alterations found in animals with denuded palate bone. These results support the potential clinical usefulness of BOM substitutes for the treatment of patients with cleft palate and other conditions in which palate mucosa grafts are necessary with consequent bone denudation.


Assuntos
Materiais Biomiméticos/uso terapêutico , Fissura Palatina/terapia , Fibrina/uso terapêutico , Mucosa Bucal/química , Sefarose/uso terapêutico , Alicerces Teciduais , Animais , Órgãos Bioartificiais , Fissura Palatina/patologia , Teste de Materiais , Mucosa Bucal/transplante , Palato Duro/patologia , Coelhos , Resultado do Tratamento
9.
ACS Appl Mater Interfaces ; 8(5): 3182-92, 2016 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-26760672

RESUMO

We synthesized agarose-polycaprolactone (Agr-PCL) bicomponent and Agr-polyethylene glycol-PCL (Agr-PEG-PCL) tricomponent amphiphilic co-network (APCN) gels by the sequential nucleophilic substitution reaction between amine-functionalized Agr and activated halide terminated PCL or PCL-b-PEG-b-PCL copolymer for the sustained and localized delivery of hydrophilic and hydrophobic drugs. The biodegradability of the APCNs was confirmed using lipase and by hydrolytic degradation. These APCN gels displayed good cytocompatibility and blood compatibility. Importantly, these APCN gels exhibited remarkably high drug loading capacity coupled with sustained and triggered release of both hydrophilic and hydrophobic drugs. PEG in the APCNs lowered the degree of phase separation and enhanced the mechanical property of the APCN gels. The drug loading capacity and the release kinetics were also strongly influenced by the presence of PEG, the nature of release medium, and the nature of the drug. Particularly, PEG in the APCN gels significantly enhanced the 5-fluorouracil loading capacity and lowered its release rate and burst release. Release kinetics of highly water-soluble gemcitabine hydrochloride and hydrophobic prednisolone acetate depended on the extent of water swelling of the APCN gels. Cytocompatibility/blood compatibility and pH and enzyme-triggered degradation together with sustained release of drugs show great promise for the use of these APCN gels in localized drug delivery and tissue engineering applications.


Assuntos
Sistemas de Liberação de Medicamentos , Etilenoglicóis/química , Fluoruracila/química , Neoplasias/tratamento farmacológico , Poliésteres/química , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Etilenoglicóis/uso terapêutico , Fluoruracila/uso terapêutico , Humanos , Hidrogéis/química , Hidrogéis/uso terapêutico , Interações Hidrofóbicas e Hidrofílicas , Poliésteres/uso terapêutico , Polietilenoglicóis/química , Sefarose/química , Sefarose/uso terapêutico
10.
ScientificWorldJournal ; 2014: 564573, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25478596

RESUMO

Development of oral amphotericin B (AmB) loaded nanoparticles (NPs) demands a novel technique which reduces its toxicity and other associated problems. Packing of AmB in between two oppositely charged ions by polyelectrolyte complexation technique proved to be a successful strategy. We have developed a novel carrier system in form of polyelectrolyte complex of AmB by using chitosan (CS) and porphyran (POR) as two oppositely charged polymers with TPP as a crosslinking agent. Initially POR was isolated from Porphyra vietnamensis followed by the fact that its alkali induced safe reduction in molecular weight was achieved. Formulation was optimized using three-factor three-level (3(3)) central composite design. High concentration of POR in NPs was confirmed by sulfated polysaccharide (SP) assay. Degradation and dissolution studies suggested the stability of NPs over wide pH range. Hemolytic toxicity data suggested the safety of prepared formulation. In vivo and in vitro antifungal activity demonstrated the high antifungal potential of optimized formulation when compared with standard drug and marketed formulations. Throughout the study TPP addition did not cause any significant changes. Therefore, these experimental oral NPs may represent an interesting carrier system for the delivery of AmB.


Assuntos
Anfotericina B/química , Anfotericina B/farmacocinética , Portadores de Fármacos/química , Nanopartículas/química , Administração Oral , Anfotericina B/efeitos adversos , Anfotericina B/uso terapêutico , Antifúngicos/química , Antifúngicos/uso terapêutico , Quitosana/química , Quitosana/uso terapêutico , Portadores de Fármacos/uso terapêutico , Humanos , Concentração de Íons de Hidrogênio , Nanopartículas/uso terapêutico , Polímeros/química , Polímeros/uso terapêutico , Sefarose/análogos & derivados , Sefarose/química , Sefarose/uso terapêutico
11.
Carbohydr Polym ; 111: 366-73, 2014 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-25037363

RESUMO

Healing enhancement and pain control are critical issues on wound management. So far, different wound dressings have been developed. Among them, hydrogels are the most applied. Herein, a thermoresponsive hydrogel was produced using chitosan (deacetylation degree 95%) and agarose. Hydrogel bactericidal activity, biocompatibility, morphology, porosity and wettability were characterized by confocal microscopy, MTS assay and SEM. The performance of the hydrogel in the wound healing process was evaluated through in vivo assays, during 21 days. The attained results revealed that hydrogel has a pore size (90-400 µm) compatible with cellular internalization and proliferation. A bactericidal activity was observed for hydrogels containing more than 188 µg/mL of chitosan. The improved healing and the lack of a reactive or a granulomatous inflammatory reaction in skin lesions treated with hydrogel demonstrate its suitability to be used in a near future as a wound dressing.


Assuntos
Bandagens , Quitosana/uso terapêutico , Hidrogel de Polietilenoglicol-Dimetacrilato/uso terapêutico , Sefarose/uso terapêutico , Pele/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/uso terapêutico , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Quitosana/química , Humanos , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Ratos Wistar , Sefarose/química , Pele/citologia , Pele/patologia
12.
Res Vet Sci ; 96(1): 30-2, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24287025

RESUMO

The aim of study was to determine the influence of zinc chelate, valnemulin and it's combination on Brachyspira hyodysenteriae shedding and morphological changes of colonic mucosa in an experimental model of swine dysentery (SD). The study was performed on pigs coming from a dysentery-free herd. Animals were inoculated by B. hyodysenteriae strain B204. When the clinical signs of SD and B. hyodysenteriae shedding developed, the pigs were divided into four treatment groups. The first group was treated with zinc chelate (250 ml/1000 L in water), second group was given valnemulin in feed at 75 ppm; the third group was given a combination of both and the fourth group was control. The results demonstrated therapeutic effect of valnemulin in pigs with serious SD and did not show therapeutic effect of chelated zinc.


Assuntos
Brachyspira hyodysenteriae/crescimento & desenvolvimento , Disenteria/veterinária , Infecções por Bactérias Gram-Negativas/veterinária , Sefarose/análogos & derivados , Doenças dos Suínos/microbiologia , Animais , Colo/patologia , Diterpenos/uso terapêutico , Quimioterapia Combinada/veterinária , Disenteria/microbiologia , Disenteria/patologia , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/patologia , Imuno-Histoquímica/veterinária , Mucosa Intestinal/patologia , Sefarose/uso terapêutico , Suínos , Doenças dos Suínos/tratamento farmacológico , Doenças dos Suínos/patologia
13.
BMC Neurosci ; 13: 100, 2012 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-22889258

RESUMO

BACKGROUND: Axonal regeneration depends on many factors, such as the type of injury and repair, age, distance from the cell body and distance of the denervated muscle, loss of surrounding tissue and the type of injured nerve. Experimental models use tubulisation with a silicone tube to research regenerative factors and substances to induce regeneration. Agarose, collagen and DMEM (Dulbecco's modified Eagle's medium) can be used as vehicles. In this study, we compared the ability of these vehicles to induce rat sciatic nerve regeneration with the intent of finding the least active or inert substance. The experiment used 47 female Wistar rats, which were divided into four experimental groups (agarose 4%, agarose 0.4%, collagen, DMEM) and one normal control group. The right sciatic nerve was exposed, and an incision was made that created a 10 mm gap between the distal and proximal stumps. A silicone tube was grafted onto each stump, and the tubes were filled with the respective media. After 70 days, the sciatic nerve was removed. We evaluated the formation of a regeneration cable, nerve fibre growth, and the functional viability of the regenerated fibres. RESULTS: Comparison among the three vehicles showed that 0.4% agarose gels had almost no effect on provoking the regeneration of peripheral nerves and that 4% agarose gels completely prevented fibre growth. The others substances were associated with profuse nerve fibre growth. CONCLUSIONS: In the appropriate concentration, agarose gel may be an important vehicle for testing factors that induce regeneration without interfering with nerve growth.


Assuntos
Colágeno/uso terapêutico , Regeneração Nervosa/efeitos dos fármacos , Próteses e Implantes , Neuropatia Ciática/cirurgia , Sefarose/uso terapêutico , Animais , Axônios/efeitos dos fármacos , Axônios/patologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Fibras Nervosas Mielinizadas/efeitos dos fármacos , Regeneração Nervosa/fisiologia , Ratos , Ratos Wistar , Nervo Isquiático/efeitos dos fármacos , Nervo Isquiático/patologia , Neuropatia Ciática/tratamento farmacológico , Neuropatia Ciática/patologia , Silicones/uso terapêutico , Fatores de Tempo
14.
Neurosci Lett ; 519(2): 103-14, 2012 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-22366403

RESUMO

Natural biomaterials are well positioned to play a significant role in the development of the next generation of biomaterials for nervous system repair. These materials are derived from naturally occurring substances and are highly diverse and versatile. They are generally biocompatible and are well tolerated in vivo, and therefore have a high potential to be successful as part of clinical repair strategies in the nervous system. Here we review recent reports on acellular tissue grafts, collagen, hyaluronan, fibrin, and agarose in their use to repair the nervous system. In addition, newly developed advanced fabrication techniques to further develop the next generation natural biomaterials-based therapeutic devices are discussed.


Assuntos
Materiais Biocompatíveis/química , Materiais Biocompatíveis/uso terapêutico , Doenças do Sistema Nervoso/terapia , Engenharia Tecidual/métodos , Animais , Colágeno/química , Colágeno/uso terapêutico , Fibrina/química , Fibrina/uso terapêutico , Humanos , Ácido Hialurônico/química , Ácido Hialurônico/uso terapêutico , Sefarose/química , Sefarose/uso terapêutico , Alicerces Teciduais , Transplantes
15.
Artigo em Chinês | MEDLINE | ID: mdl-21485192

RESUMO

In this paper, a kind of skin dressing, agarose- grafting- hyaluronic acid (Ag-g-HA) sponge was applied to test the modified agarose based scaffold for skin regeneration. The bFGF loading agarose-grafting hyaluronan scaffold had homogenous porosities, and the loaded bFGF was bioactive in 2 weeks. The Ag-g-HA sponge was applied into skin of mice, and it was found that the dressing promoted skin regeneration and no infection and leakage in lesion site took place. H&E staining results showed that the repaired skin was similar to autologous skin. These demonstrate that Ag-g-HA sponge has a promise in skin regeneration.


Assuntos
Bandagens , Ácido Hialurônico/uso terapêutico , Sefarose/uso terapêutico , Tampões de Gaze Cirúrgicos , Ferimentos e Lesões/terapia , Animais , Feminino , Fator 2 de Crescimento de Fibroblastos/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Polissacarídeos/isolamento & purificação , Polissacarídeos/uso terapêutico , Distribuição Aleatória , Alga Marinha/química , Sefarose/isolamento & purificação , Cicatrização/efeitos dos fármacos
16.
Spine (Phila Pa 1976) ; 35(8): 867-73, 2010 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-20354467

RESUMO

STUDY DESIGN: To develop a construction algorithm in which electrospun nanofibrous scaffolds are coupled with a biocompatible hydrogel to engineer a mesenchymal stem cell (MSC)-based disc replacement. OBJECTIVE: To engineer a disc-like angle-ply structure (DAPS) that replicates the multiscale architecture of the intervertebral disc. SUMMARY OF BACKGROUND DATA: Successful engineering of a replacement for the intervertebral disc requires replication of its mechanical function and anatomic form. Despite many attempts to engineer a replacement for ailing and degenerated discs, no prior study has replicated the multiscale hierarchical architecture of the native disc, and very few have assessed the mechanical function of formed neo-tissues. METHODS: A new algorithm for the construction of a disc analogue was developed, using agarose to form a central nucleus pulposus (NP) and oriented electrospun nanofibrous scaffolds to form the anulus fibrosus region (AF). Bovine MSCs were seeded into both regions and biochemical, histologic, and mechanical maturation were evaluated with in vitro culture. RESULTS: We show that mechanical testing in compression and torsion, loading methods commonly used to assess disc mechanics, reveal equilibrium and time-dependent behaviors that are qualitatively similar to native tissue, although lesser in magnitude. Further, we demonstrate that cells seeded into both AF and NP regions adopt distinct morphologies that mirror those seen in native tissue, and that, in the AF region, this ordered community of cells deposit matrix that is organized in an angle-ply configuration. Finally, constructs demonstrate functional development with long-term in vitro culture. CONCLUSION: These findings provide a new approach for disc tissue engineering that replicates multi-scale form and function of the intervertebral disc, providing a foundation from which to build a multi-scale, biologic, anatomically and hierarchically relevant composite disc analogue for eventual disc replacement.


Assuntos
Deslocamento do Disco Intervertebral/cirurgia , Teste de Materiais/métodos , Transplante de Células-Tronco Mesenquimais/métodos , Desenho de Prótese/métodos , Engenharia Tecidual/métodos , Alicerces Teciduais/tendências , Algoritmos , Animais , Fenômenos Biomecânicos/fisiologia , Bovinos , Células Cultivadas , Força Compressiva/fisiologia , Matriz Extracelular/fisiologia , Fibrocartilagem/citologia , Fibrocartilagem/fisiologia , Humanos , Hidrogéis/uso terapêutico , Disco Intervertebral/citologia , Disco Intervertebral/fisiologia , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/fisiologia , Nanofibras/uso terapêutico , Sefarose/uso terapêutico , Alicerces Teciduais/normas , Suporte de Carga/fisiologia
17.
Artigo em Inglês | MEDLINE | ID: mdl-19615639

RESUMO

BACKGROUND: Many fillers have been used to augment lips. Agarose gel is a new and absorbable filler indicated for the correction of soft tissues and lip. OBJECTIVE: This article reviews the results of 68 cases that have undergone lip augmentation with this new filler in the last 3 years. STUDY DESIGN: A total of 68 patients received agarose gel for treatment for lip augmentation in a 3-year period from 2005 to 2008. Each of the patients signed an informed consent form. The patients were between 35 and 70 years of age. Three patients were male, and 65 were female. A volume of 0.5-1.0 mL of agarose gel was sufficient for each lip. A bigger volume may result in a dense mass and pain. All patients were successfully treated with injections of agarose gel. RESULTS: Clinical improvement was noted immediately, and only mild bruising was recorded. All of the the patients returned to the clinic 10 days after treatment for follow-up, and all felt that an excellent cosmetic result was obtained. The patients were told to return after an additional month for follow-up and possible reinjection. The results lasted approximately 5 months with a gradual decline to baseline. The agarose gel was very well tolerated with only a few mild adverse reactions that resolved spontaneously. CONCLUSION: During 3 years of clinical use, agarose gel proved to be a reliable and predictable treatment for lip augmentation.


Assuntos
Materiais Biocompatíveis/uso terapêutico , Técnicas Cosméticas , Lábio/cirurgia , Sefarose/uso terapêutico , Adulto , Idoso , Feminino , Seguimentos , Géis , Humanos , Injeções Subcutâneas , Masculino , Pessoa de Meia-Idade , Próteses e Implantes , Resultado do Tratamento
18.
Cell Transplant ; 18(8): 933-9, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19500478

RESUMO

Cell transplantation after enclosing in microcapsules has been studied as an alternative approach for treatment of wide variety of diseases. In the present study, we examined the feasibility of using agarose microcapsules, having a cell-enclosing hollow core of 100-150 microm in diameter and agarose gel membrane of about 20 microm in thickness, as a device for the methodology. We enclosed cells that had been genetically engineered to express cytochrome P450 2B1, an enzyme that activates the anticancer prodrug ifosfamide. The enclosed cells were shown to express the enzymatic function in the microcapsules in that they suppressed the growth of tumor cells in medium containing ifosfamide. In addition, a more significant regression of preformed tumors was observed in the nude mice implanted with the cell-enclosing microcapsules compared with those implanted with empty capsules after administration of ifosfamide. Preformed tumors shrank by less than 40% in volume in 6 of the 10 recipients implanted with cell-enclosing microcapsules. In contrast, only 1 in 10 of the preformed tumors in the recipient implanted with empty microcapsules shrank by this amount. These results suggest that agarose microcapsules containing cytochrome P450 2B1 enzyme-expressing cells are feasible devices for improving the chemotherapy of tumors. Thus, agarose microcapsule having hollow cores are generally a good candidate as vehicles for cell-encapsulation approaches to cell therapy.


Assuntos
Cápsulas/uso terapêutico , Transplante de Células/métodos , Terapia Baseada em Transplante de Células e Tecidos/métodos , Ifosfamida/administração & dosagem , Sefarose/uso terapêutico , Neoplasias Cutâneas/terapia , Animais , Antineoplásicos Alquilantes/administração & dosagem , Cápsulas/química , Células Cultivadas , Terapia Combinada , Citocromo P-450 CYP2B1/genética , Citocromo P-450 CYP2B1/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Sefarose/química , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Artif Organs ; 31(3): 208-14, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17343696

RESUMO

The use of monoclonal antibodies (MAbs) in cytotoxic conjugates (radionuclides, toxins, or drugs) for targeting tumor cells is restricted due to toxicity in vital organs. Through improved tumor targeting, it is possible to administer larger amounts of such labeled MAbs, thus improving the ability to eradicate tumor cells without increased normal organ toxicity. Extracorporeal affinity adsorption treatment (ECAT) has therefore been developed using an avidin-agarose (AA) adsorbent with high binding affinity for the biotinylated radiolabeled MAb, rituximab. During ECAT, excess radioimmunoconjugates, not bound to the tumor cells, can be removed improving tumor targeting. The present study was performed to estimate the biocompatibility of the AA adsorber. Seven patients with B-cell lymphoma not responding to conventional treatment were studied. During the ECAT procedure, blood (B) components, plasma (P) complement fragments C3a, C5a, and P-bradykinin were analyzed, and other laboratory tests were carried out. Slight decreases in B-hemoglobin (8.3%), B-thrombocytes (11.4%), and P-albumin (14.3%) were observed, and could be explained by the dilution of the blood with normal saline and acid citrate dextrose. The AA adsorbent had no effect on the blood cells, immunological status or P-bradykinin level. The AA adsorber demonstrated good hemocompatibility and biocompatibility, without any side effects in the patients.


Assuntos
Avidina/uso terapêutico , Circulação Extracorpórea/instrumentação , Hemoperfusão/métodos , Linfoma de Células B/radioterapia , Radioimunoterapia/métodos , Sefarose/uso terapêutico , Adsorção , Adulto , Idoso , Anticorpos Monoclonais/uso terapêutico , Avidina/sangue , Avidina/química , Feminino , Hemoperfusão/instrumentação , Humanos , Masculino , Teste de Materiais , Pessoa de Meia-Idade , Radioisótopos/química , Radioisótopos/uso terapêutico , Terapia de Salvação/métodos , Sefarose/sangue , Sefarose/química
20.
Artif Organs ; 30(8): 606-14, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16911314

RESUMO

This work investigated the potential use of an alternative adsorbent to anti-immunoglobulin E (IgE)-agarose for IgE selective adsorption therapy. A screening of several commercially available adsorbents (Concanavalin A, Lens culinaris[Lc], d-tryptophan, poly-l-lysine, and aminohexyl immobilized on agarose) was done through batch system assays, considering some criteria, such as adsorption capacity, selectivity, and biocompatibility. In the Lc-agarose adsorbent, total IgE, and specific IgE--for the airborne allergens Dermatophagoides pteronyssinus and Blomia tropicalis--were significantly better removed (63, 58, and 59%, respectively) than immunoglobulin G (19%), immunoglobulin A (33%), immunoglobulin M (9%), and albumin (18%). This adsorbent was packed into a column and the effect of superficial velocity, ratio of plasma volume to bed volume, number of perfusions, and temperature on IgE adsorption were evaluated. In vitro simulation of therapeutic adsorption (single perfusion) indicated that about 50% of total IgE could be eliminated.


Assuntos
Remoção de Componentes Sanguíneos/métodos , Imunoglobulina E/metabolismo , Imunoadsorventes/farmacocinética , Adsorção , Cromatografia em Agarose/métodos , Convertases de Complemento C3-C5/metabolismo , Circulação Extracorpórea/métodos , Humanos , Hipersensibilidade/terapia , Técnicas de Imunoadsorção , Imunoadsorventes/uso terapêutico , Ligantes , Lectinas de Plantas/farmacocinética , Lectinas de Plantas/uso terapêutico , Polilisina/análogos & derivados , Polilisina/farmacocinética , Polilisina/uso terapêutico , Sefarose/análogos & derivados , Sefarose/farmacocinética , Sefarose/uso terapêutico , Triptofano/farmacocinética , Triptofano/uso terapêutico
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