scholarly journals Optimization and Evaluation of Al18F Labeling Using a NOTA—or RESCA1-Conjugated AE105 Peptide Antagonist of uPAR

2021 ◽  
Vol 1 ◽  
Author(s):  
Troels E. Jeppesen ◽  
Marina Simón ◽  
Josephine Torp ◽  
Line B. S. Knudsen ◽  
Julie Maja Leth ◽  
...  

Fluorine-18 displays almost ideal decay properties for positron emission tomography (PET) and allows for large scale production. As such, simplified methods to radiolabel peptides with fluorine-18 are highly warranted. Chelation of aluminium fluoride-18 toward specific peptides represents one method to achieve this. With the current methods, chelation of aluminium fluoride-18 can be achieved using NOTA-conjugated peptides. However, the heating to 90–100◦C that is required for this chelation approach may be deleterious to the targeting moiety of the probe. Recently, a new chelator, RESCA1, was developed allowing Al18F chelation at room temperature. Here, we optimize the labeling procedure enabling high chelation efficacy of fluoride-18 at 22◦C, even at full batch labeling. The optimized procedure was tested by Al18F-labeling of RESCA1-AE105—a uPAR targeting peptide. NOTA-AE105 was also labeled with Al18F, and the two peptides were compared head-to-head. [18F]AlF-NOTA-AE105 and [18F]AlF-RESCA1-AE105 could be produced in equal radiochemical yields (RCY), radiochemical purities (RCP) and molar activities. Additionally, the two peptides showed comparable binding affinity to uPAR and uptake in cells expressing the uPAR, when evaluated in vitro. Overall, we found that the performances of [18F]AlF-NOTA-AE105 and [18F]AlF-RESCA1-AE105 were grossly comparable, but importantly RESCA1 can be labeled with aluminium fluoride-18 at 22◦C. Consequently, this study showed that RESCA1 is superior to NOTA with respect to Al18F chelation of temperature sensitive molecules, such as thermolabile peptides and proteins as well as that full batch chelation of RESCA1 with fluoride-18 is possible.

2014 ◽  
Vol 69 ◽  
pp. 21-27 ◽  
Author(s):  
Valeria Cavallaro ◽  
Cristina Patanè ◽  
Salvatore L. Cosentino ◽  
Isabella Di Silvestro ◽  
Venera Copani

1985 ◽  
Vol 5 (7) ◽  
pp. 1795-1799
Author(s):  
D R Kaplan ◽  
B Bockus ◽  
T M Roberts ◽  
J Bolen ◽  
M Israel ◽  
...  

A recombinant plasmid containing a metallothionein promoter-polyoma middle T cDNA fusion was constructed and used to transfect NIH 3T3 cells. Transformed cells expressing middle T were injected into nude mice. Within 3 weeks, each mouse produced tumors containing middle T equivalent to that in 250 to 1,000 100-mm dishes of polyomavirus-infected cells. This middle T, partially purified by immunoaffinity chromatography, retained activity as measured by its ability to be phosphorylated in vitro. The combined approach of fusing strong promoters to genes of interest and utilizing nude mice to grow large quantities of cells expressing the gene provides a quick, inexpensive alternative to other expression systems.


2017 ◽  
Vol 9 (3) ◽  
pp. 371-377
Author(s):  
Charles Oluwaseun ADETUNJI ◽  
Julius Kola OLOKE ◽  
Gandham PRASAD ◽  
Moses ABALAKA ◽  
Emenike Onyebum IROKANULO

Formulation of effective and environmental friendly bioherbicides depends on the type of fermentation medium used for the production of phytotoxic metabolites. The effect of biomass, colony forming unit and the phytotoxic metabolite produced from the biphasic fermentation was carried out, while the phytotoxic metabolite was  tested in vivo and in-vitro on Echinochola crus-galli and dicotyledonous Chromolaena odorata. The mutant strain of Lasiodiplodia pseudotheobromae C1136 (Lp90) produced the highest amount of conidia and the largest necrotic area on the two tested weeds when compared to its wild strain in the different biphasic media combinations. The study revealed that the biphasic system containing PDB + rice produced the highest bioherbicidal activities. Therefore, the phytotoxic metabolites from strain C1136 are suggested for large scale production of bioherbicides for the management of weeds in conventional farming to improve yield and enhance food security.


1985 ◽  
Vol 5 (7) ◽  
pp. 1795-1799 ◽  
Author(s):  
D R Kaplan ◽  
B Bockus ◽  
T M Roberts ◽  
J Bolen ◽  
M Israel ◽  
...  

A recombinant plasmid containing a metallothionein promoter-polyoma middle T cDNA fusion was constructed and used to transfect NIH 3T3 cells. Transformed cells expressing middle T were injected into nude mice. Within 3 weeks, each mouse produced tumors containing middle T equivalent to that in 250 to 1,000 100-mm dishes of polyomavirus-infected cells. This middle T, partially purified by immunoaffinity chromatography, retained activity as measured by its ability to be phosphorylated in vitro. The combined approach of fusing strong promoters to genes of interest and utilizing nude mice to grow large quantities of cells expressing the gene provides a quick, inexpensive alternative to other expression systems.


2021 ◽  
Author(s):  
Teresa P. Silva ◽  
Rui Sousa-Luís ◽  
Tiago G. Fernandes ◽  
Evguenia P. Bekman ◽  
Carlos A. V. Rodrigues ◽  
...  

AbstractHuman induced pluripotent stem cells (iPSCs) have great potential for disease modeling. However, generating iPSC-derived models to study brain diseases remains a challenge. In particular, the ability to recapitulate cerebellar development in vitro is still limited. We presented a reproducible and scalable production of cerebellar organoids by using the novel Vertical-Wheel single-use bioreactors, in which functional cerebellar neurons were obtained. Here, we evaluate the global gene expression profiles by RNA sequencing (RNA-seq) across cerebellar differentiation, demonstrating a faster cerebellar commitment in this novel dynamic differentiation protocol. Furthermore, transcriptomic profiles suggest a significant enrichment of extracellular matrix (ECM) in dynamic-derived cerebellar organoids, which can better mimic the neural microenvironment and support a consistent neuronal network. Thus, an efficient generation of organoids with cerebellar identity was achieved for the first time in a continuous process using a dynamic system without the need of organoids encapsulation in ECM-based hydrogels, allowing the possibility of large-scale production and application in high-throughput processes. The presence of factors that favors angiogenesis onset was also detected in dynamic condition, which can enhance functional maturation of cerebellar organoids. We anticipate that large-scale production of cerebellar organoids may help developing models for drug screening, toxicological tests and studying pathological pathways involved in cerebellar degeneration.


Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2078
Author(s):  
Tristan K. Adams ◽  
Nqobile A. Masondo ◽  
Pholoso Malatsi ◽  
Nokwanda P. Makunga

The development of a protocol for the large-scale production of Cannabis and its variants with little to no somaclonal variation or disease for pharmaceutical and for other industrial use has been an emerging area of research. A limited number of protocols have been developed around the world, obtained through a detailed literature search using web-based database searches, e.g., Scopus, Web of Science (WoS) and Google Scholar. This article reviews the advances made in relation to Cannabis tissue culture and micropropagation, such as explant choice and decontamination of explants, direct and indirect organogenesis, rooting, acclimatisation and a few aspects of genetic engineering. Since Cannabis micropropagation systems are fairly new fields, combinations of plant growth regulator experiments are needed to gain insight into the development of direct and indirect organogenesis protocols that are able to undergo the acclimation stage and maintain healthy plants desirable to the Cannabis industry. A post-culture analysis of Cannabis phytochemistry after the acclimatisation stage is lacking in a majority of the reviewed studies, and for in vitro propagation protocols to be accepted by the pharmaceutical industries, phytochemical and possibly pharmacological research need to be undertaken in order to ascertain the integrity of the generated plant material. It is rather difficult to obtain industrially acceptable micropropagation regimes as recalcitrance to the regeneration of in vitro cultured plants remains a major concern and this impedes progress in the application of genetic modification technologies and gene editing tools to be used routinely for the improvement of Cannabis genotypes that are used in various industries globally. In the future, with more reliable plant tissue culture-based propagation that generates true-to-type plants that have known genetic and metabolomic integrity, the use of genetic engineering systems including “omics” technologies such as next-generation sequencing and fast-evolving gene editing tools could be implemented to speed up the identification of novel genes and mechanisms involved in the biosynthesis of Cannabis phytochemicals for large-scale production.


2021 ◽  
Author(s):  
Jingyue Wang ◽  
Xinan Xu ◽  
Fangkun Zhao ◽  
Nan Yin ◽  
Zhijiang Zhou ◽  
...  

Abstract Purpose: The yield of levan extracted from microbial fermentation broth is low, so in vitro catalytic synthesis of levan by levansucrase is expected to be one of the industrial production approaches of levan. Methods: A recombinant plasmid pET-28a-AcmA-Z constructed in the previous study was used to produce levansucrase. The effects of temperature, pH, and metal ions on the levan formation activity of the levansucrase were investigated. The polymer was analyzed by means of HPIC, FTIR, NMR techniques.Results: The recombinant levansucrase could be easily purified in one step and the purified enzyme had a single band clearly visible in SDS-PAGE. The conditions for enzymatic reactions was optimal at pH 5.2 and 40 ℃, and the activity of enzymes was stimulated by K+ and Ca2+. The yield of levan biosynthesis from 10% (w/v) sucrose with 6.45 U/g sucrose of levansucrase was 30.6 g/L. The molecular weight of the levan was about 1.56×106 Da, as measured by GPC. HPIC analysis showed that the monosaccharide composition of the levan was fructose and glucose. The results of FTIR and NMR analysis indicated that the polymer produced by the recombinant levansucrase was β-(2, 6) levan.Conclusions: The results of this study provide a basis for large-scale production of levan by enzymatic method.


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