Improving Carbon and Energy Distribution by Coupling Growth and Medium Chain Length Polyhydroxyalkanoate Production from Fatty Acids by Pseudomonas putida KT2440

Nicolas Andin,Antoine Longieras,Thierry Veronese,Frédéric Marcato,Carole Molina-Jouve,Jean-Louis Uribelarrea 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.3

The production of medium chain length polyhydroxyalkanoates by Pseudomonas putida KT2440 from fatty acids leads to the loss of a large proportion of carbon. We studied the possibility of a shift of potentially available energy and carbon towards monitored residual growth during the production phase. A Fed-Batch culture achieving 125.6 g/L of total biomass containing 54.4% (g/g) of medium chain length polyhydroxyalkanoates was carried out leading to an overall experimental carbon yield of 0.7 Cmole/Cmole. The analysis of modeling fluxes deduced from experimental data indicated how carbon and reduced cofactors (NADH and FADH2) were managed to conclude that part of the carbon and reduced cofactors made available by polymer production were used in anabolic pathways. The strategy which consisted in coupled growth and medium chain length polyhydroxyalkanoate production enhanced the global yields compared to growth followed by a production phase. The understanding of carbon and energy fluxes distribution allowed deducing optimized culture strategy to perform the highest reported in the literature.

Efficacy of instillation of MB49 cells and thermoreversible polymeric gel in urothelial bladder carcinoma immunization

Jhonne Pedro Pedott Santana,Priscyla Daniely Marcato,Tais Nader Chrysostomo Massaro,Naiane Lima Godoy,Fernanda de Freitas Anibal,Borra Ricardo Carneiro 한국실험동물학회 2022 Laboratory Animal Research Vol.38 No.2

Background: Activating the immune system for therapeutic benefit has long been a goal in immunology, especially in cancer treatment, but the low immunogenicity of antitumor vaccines remains a limiting factor in the fight against malignant neoplasms. The increase in the immunogenicity of weak antigens using biodegradable polymers, such as chitosan, has been observed in the field of cancer immunotherapy. However, the effects of the vaccine using a combination of tumor cells and a thermoreversible delivery system based on chitosan in bladder cancer models, mainly using the intravesical route to stimulate the antitumor immune response, are unknown. We propose to evaluate the efficacy of a polymeric gel matrix (TPG) formed by poloxamer 407 and chitosan, associated with MB49 cells, as an intravesical antitumor vaccine using a C57BL/6 murine model of bladder urothelial carcinoma. The effectiveness of immunization was analyzed with the formation of three experimental groups: Control, TPG and TPG + MB49. In the vaccination phase, the TPG + MB49 group underwent a traumatic injury to the bladder wall with immediate intravesical instillation of the vaccine compound containing MB49 cells embedded in TPG. The TPG group was subjected to the same procedures using the compound containing the gel diluted in medium, and the control group using only the medium. After 21 days, the animals were challenged with tumor induction. Results: In vitro tests showed loss of viability and inability to proliferate after exposure to TPG. In vivo tests showed that animals previously immunized with TPG + MB49 had higher cumulative survival, as well as significantly lower bladder weight and size in contrast to the other two groups that did not show a statistically different tumor evolution. In addition, the splenocytes of these animals also showed a higher rate of antitumor cytotoxicity in relation to the TPG and control groups. Conclusions: We can conclude that MB49 cells embedded in a polymeric thermoreversible gel matrix with chitosan used in the form of an intravesical vaccine are able to stimulate the immune response and affect the development of the bladder tumor in an orthotopic and syngeneic C57BL/6 murine model.

Immunohistochemical expression of h-telomerase reversetranscriptase in canine and feline meningiomas

Luciana Mandrioli,Alessandro Cesari,Maria Teresa Mandara,Paolo Stefano Marcato,Giuliano Bettini,Serena Panarese 대한수의학회 2007 Journal of Veterinary Science Vol.8 No.2

Telomere length maintenance is regarded as a fundamental step in tumorigenesis, as most human brain tumors, including meningiomas, stabilize the ends of their chromosomes using telomerase. This investigation represents an introduction to telomerase expression in canine and feline meningiomas. Twenty-five archived cases (14 dogs and 11 cats) were immunohistochemically tested for human-telomerase reverse transcriptase (h- TERT), scored, and quantified; furthermore, mitoses were counted on sections stained with a modified toluidine blue. The h-TERT antibody immunolabelled the nucleus and nucleolus of meningeal neoplastic cells, with an intensity ranging from mild to strong and a speckled distribution; a significantly higher expression in cats was noted, while no significant association between h-TERT immunolabelling and sex or histotype was evident in dogs or cats. The telomerase enzyme represents a fundamental parameter of potential malignant transformation, which may occur independently of the signal to proliferate, thereby supplying the cells with unlimited growth capabilities. Telomerase expression could be a prognostic indicator independent of the kinetic parameters, although this should be evaluated using a larger dataset with available clinical information.

Microencapsulation of Antibiotic Rifampicin in Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

Duran, N.,Alvarenga, M.A.,Da Silva, E.C.,Melo, P.S.,Marcato, P.D. 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.11

The aim of this study was the preparation of microparticles containing rifampicin using a biodegradable polymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) for oral administration produced by a bacteria. The poly(3-hydroxybutyrate-co-3-hydroxyvalerate) microparticles with and without rifampicin were prepared by the emulsification and solvent evaporation method, in which chloroform and polyvinyl alcohol are used as the solvent and emulsifier, respectively. Microparticles were obtained within a size range of $20-60{\mu}m$ by changing the initial poly(3-hydroxybutyrate-co-3-hydroxyvalerate), polyvinyl alcohol and rifampicin concentrations. An encapsulation efficiency value of 14% was obtained. The optimized total yield of 60% of the poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/ rifampicin was obtained. A load of 0.035 mg/1mg of PHBV was reached. Almost 90% of the drug loaded in the micro-particles was released after 24 h. The size, encapsulation efficiency and ribampicin release of the micro-particles varied as a function of the initial poly(3-hydroxybutyrate-co-3-hydroxyvalerate), polyvinyl alcohol and rifampicin concentrations. It was demonstrated that the microencapsulated rifampicin, although was not totally available in the medium, exhibited a similar inhibition value as free rifampicin at 24 h of incubation with S. aureus. Cytotoxicity assays demonstrated a reduction of the toxicity when rifampicin was microencapsulated in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) while maintaining its antibacterial activity.

Microencapsulation of Antibiotic Rifampicin in Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

N.Duran,M.A. Alvarenga,E.C. Da Silva,P.S. Melo,P.D. Marcato 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.11

The aim of this study was the preparation of microparticles containing rifampicin using a biodegradable polymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) for oral administration produced by a bacteria. The poly(3-hydroxybutyrate-co-3-hydroxyvalerate) microparticles with and without rifampicin were prepared by the emulsification and solvent evaporation method, in which chloroform and polyvinyl alcohol are used as the solvent and emulsifier, respectively. Microparticles were obtained within a size range of 20-60 μm by changing the initial poly(3-hydroxybutyrate-co-3-hydroxyvalerate), polyvinyl alcohol and rifampicin concentrations. An encapsulation efficiency value of 14% was obtained. The optimized total yield of 60% of the poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/ rifampicin was obtained. A load of 0.035 mg/1 mg of PHBV was reached. Almost 90% of the drug loaded in the microparticles was released after 24 h. The size, encapsulation efficiency and ribampicin release of the microparticles varied as a function of the initial poly(3-hydroxybutyrate-co-3-hydroxyvalerate), polyvinyl alcohol and rifampicin concentrations. It was demonstrated that the microencapsulated rifampicin, although was not totally available in the medium, exhibited a similar inhibition value as free rifampicin at 24 h of incubation with S. aureus. Cytotoxicity assays demonstrated a reduction of the toxicity when rifampicin was microencapsulated in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) while maintaining its antibacterial activity.