Blood Plasma Medium Research Articles

Isolation and Culture of Non-adherent Cells for Cell Reprogramming.

Coronary heart disease (CHD) is a leading cause of death globally, while its current management is limited to reducing the myocardial infarction area without actually replacing dead cardiomyocytes. Direct cell reprogramming is a method of cellular cardiomyoplasty which aims for myocardial tissue regeneration, and CD34+ cells are one of the potential sources due to their shared embryonic origin with cardiomyocytes. However, the isolation and culture of non-adherent CD34+ cells is crucial to obtain adequate cells for high-efficiency genetic modification. This study aimed to investigate the optimal method for isolation and culture of CD34+ peripheral blood cells using certain culture media. A peripheral blood sample was obtained from a healthy subject and underwent pre-enrichment, isolation, and expansion. The culture was subsequently observed for their viability, adherence, and confluence. Day 0 observation of the culture showed a healthy CD34+ cell with a round cell shape, without any adherent cells present yet. Day 4 of observation showed that CD34+ cells within the blood plasma medium became adherent, indicated by their transformations into spindle or oval morphologies. Meanwhile, CD34+ cells in vitronectin and fibronectin media showed no adherent cells and many of them died. Day 7 observation revealed more adherent CD34+ cells in blood plasma medium, and which had 75% of confluence. In conclusion, the CD34+ cells that were isolated using a combination of density and magnetic methods may be viable and adequately adhere in culture using blood plasma medium, but not in cultures using fibronectin and vitronectin.

Biological and microbiological performance of new polymer-based chitosan and synthesized amino-cyclodextrin finished polypropylene abdominal wall prosthesis biomaterial

This study deals with the development of a polypropylene (PP) artificial abdominal wall prosthesis textile with improved biological and antibiotic delivery properties. This added functionality was obtained by finishing of PP prosthesis textile with chitosan (CS), synthesized per-amino-cyclodextrin (CD-NH2) and polyacrylic acid (PAA). The finishing process involved polymerization between the three last mentioned reactants, which generated a cross-linked polymer that coated the PP surface meshes. Then different characterizations were performed on our wash-resistant functionalization to evaluate its efficiency. Firstly, wettability performance, for various grafting rates of the PP biomaterials, was assessed via the drop contact angle technique. Then, a mechanical characterization through an evaluation of the tensile strength revealed no influence of our grafting procedure on these properties. Scanning electron microscopy analysis was performed to evaluate the grafting mode and its effectiveness. Inclusion complex formation between the ciprofloxacin and both CD-NH2 and its polymer were studied via isothermal titration calorimetry measurements. Antibiotic sorption capacities of treated and untreated textile samples were then studied by batch assessments coupled with spectrophotometric analysis. The biological and microbiological properties of the PP mesh functionalized with the CS-CD-NH2 polymer and charged by selected antibiotic were assessed by cell culture analysis. After 3 and 6 days of cell contact, the results revealed an improved proliferation and adhesion of NIH3T3 fibroblastic cells and no obvious cytotoxicity on the chemical functionalized substrate. Finally, in vitro antimicrobial activity of the CS-CD-NH2-grafted PP biomaterial previously loaded with antibiotic was evaluated against the different bacteria strains, Staphylococcus aureus, Enterococcus faecalis and Escherichia coli. Results revealed a greatly superior activity with the functionalized PP meshes compared to that of the untreated PP within a 24 h batch experiment in human blood plasma medium. In summary, the different results from the present study provide an insight into the efficient performance of CS/CD-NH2 polymer as drug delivery system for various applications in the field of medical biomaterials.

A theoretical study on magnetic properties of bis-TEMPO diradicals with possible application

Three different pairs of isomeric trans and corresponding cis forms of fluoroprotein chromophore (FPC) fragments coupled bis-2,2′,6,6′-tetramethylpiperidinyloxy (TEMPO) based diradicals have been designed, and subsequently the magnetic properties of these diradicals have been investigated. We have used blue shifted variants of green fluorescent protein (cyan fluorescent protein or CFP), orange variant of Discosoma coral (DsRed) and yellow mutant of Zoanthus sp. (zFP) chromophore fragments as spin couplers. Along with the gas phase magnetic exchange coupling constant (J), the zero field splitting parameters (ZFSs) of all the diradicals in water and also in blood plasma medium have been calculated. We have found the all molecules to be ferromagnetic in nature with trans diradicals having lower spin–spin ZFS parameter (|D|) and the higher magnetic exchange coupling constants values than their respective fluorescent cis isomers. This has also been noted that due to the presence of the fluoroprotein chromophores, the resulting diradicals can switch back and forth between the isomeric trans and cis forms upon irradiation of the proper wavelength of light. The time dependent density functional (TDDFT) technique is used to measure the actual wavelength of this conversion for these diradicals. A comparison between the evaluated ZFS values with other nitroxide based synthesized molecular systems which are in use as magnetic resonance imaging (MRI) contrast agents (MRICAs) indicates that if these diradicals are synthesized, they can be useful as MRICAs. A relation between the distance and the spin–spin ZFS parameter is also made. To support this fact, we have computed the solvent accessible surface area, molecular volume, the surface to volume ratio, and molecular diameter of each diradical species to address their potentiality to act as contrast agents in MRI. Finally the ability of these diradicals to act as MRICAs is further justified with the help of molecular electrostatic potential surfaces.

A theoretical study on photomagnetic fluorescent protein chromophore coupled diradicals and their possible applications

We have designed and theoretically studied three different pairs of green fluorescent protein chromophores and their different homologue-based diradicals coupled with imino nitroxides. To begin with, the geometries of all these diradicals have been optimized at high spin (HS) state in the gas phase, in a water medium and in a blood plasma medium. The process of calculations is straightforward and well-established in the case of the gas phase. However, for calculations in water, we have adopted our own N-layer integrated molecular orbital and molecular mechanics (ONIOM) method. Similarly for the blood phase calculations, the polarized continuum model (PCM) method has been adopted. With these optimized geometries the magnetic exchange coupling constant (J) values are estimated for these diradicals in different media using the broken symmetry (BS) approach in an unrestricted DFT framework. In order to obtain the BS solutions in the ONIOM method, we have carried out ONIOM-BS, where the BS calculations are done for the inner high-level layer (diradical system) keeping the outer water layer at low level. In a similar fashion, a PCM-BS technique has also been adopted for the BS calculations in the PCM method. We have found that these diradicals have an ability to change their magnetic nature from antiferromagnetic in the trans form to ferromagnetic in the cis form upon irradiation of light with the appropriate wavelength. Using a time-dependent DFT (TDDFT) technique, the required wavelengths of light by which non-fluorescent dark trans diradicals turn into their corresponding bright fluorescent cis isomers are determined for each pair of diradicals for the gas and water media. This color change is indeed a signature of the change in magnetic state of the diradicals concerned. Here, we have also calculated the zero field splitting (ZFS) parameter (D), rhombic ZFS parameter (E) and ZFS magnitude (a2). From our calculations we ambitiously expect that if these diradicals are synthesized then they might be used as a successful, non-hazardous magnetic resonance imaging contrast agent (MRICA) in place of other metal-based contrast agents.

Absorption performance of iodixanol-imprinted polymers in aqueous and blood plasma media

This paper presents the preparation and absorption performance of iodixanol-imprinted polymers in aqueous and blood plasma media in vitro for biomedical applications. The imprinted polymers were prepared by non-covalent imprinting of iodixanol in a matrix of poly(4-vinylpyridine) crosslinked by ethylene glycol dimethacrylate. The binding capacities (BCs) were investigated as a function of template-to-monomer, as well as monomer-to-crosslinker, ratios in the polymerization, and the solvent type. The highest BC of iodixanols achieved from the optimized imprinted polymer in the aqueous solution is 284 mg g −1 dry polymer with an imprinting effect (IE) 8.8 times higher than that of the non-imprinted polymer. In blood plasma, the BC of this polymer is slightly reduced to 232 mg g −1 with a smaller IE 4.3 times higher than that of the control polymer. The BCs of molecularly imprinted polymers as a function of the initial assay solution concentration as well as the examination time are also addressed. Surface analyses were additionally performed to characterize the surface morphologies and porosities of synthetic polymers. This work has demonstrated the feasibility of molecular imprinting of iodixanol, and the observed absorption performance of the imprinted polymers is encouraging for biomedical applications.

Fluorescent coumarinyldithiane as a selective chemodosimeter for mercury(II) ion in aqueous solution

A coumarin-based dithiane ( 1) was synthesized for the selective detection of Hg 2+ with respect to dual chromo- and fluorogenic changing events in an aqueous solution by the mercury-promoted transformation of a dithiane group into an aldehyde functional unit. The Hg 2+-selective response of the chemodosimeter was clearly observed in aqueous buffer as well as in human blood plasma medium.

Chemical, biological and microbiological evaluation of cyclodextrin finished polyamide inguinal meshes

This study describes the use of cyclodextrins (CDs) as a finishing agent of polyamide (PA) fibers used in order to obtain inguinal meshes with improved antibiotic delivery properties. The finishing process involved polymerization between citric acid and CDs, which yielded a cross-linked polymer that physically adhered to the surface of PA fibers. This permanent functionalization was characterized by evaluating the damping property with a polar liquid (glycerol) via the drop contact angle method for various rates of modification of the fabrics. The biological and microbiological effects of the PA, which were functionalized with hydroxypropylated derivate of γ-CD (HP-γ-CDs) and charged with ciprofloxacin (CFX), were evaluated by cell culture assays. We observed a good adhesion and proliferation of fibroblastic cells (NIH3T3) after 3 and 6 days and no detectable toxicity of the modified substrate. The in vitro antibacterial activity of the HP-γ-CD grafted PA fabrics charged with CFX against the bacteria Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli was greatly superior to that of the virgin sample within a 24 h batch experiment in human blood plasma medium. In conclusion, these results from our study offer an insight into the efficient performance of CDs as drug delivery systems for multiple applications in the fields of biomaterials and medical textiles.

Surface modification and characterization of some commonly used catheter materials. II. Friction characterization.

The effects of the modification of polystyrene (PS), polyethylene (PE), poly(vinyl chloride) (PVC), silicone rubber (SR), and fluorinated ethylene propylene (FEP) copolymer by radio frequency glow discharge in a helium environment were presented in part I. The hydrated polymer surfaces were characterized by XPS, SEM, visual microscopy, and by contact angle measurements. In general, exposure of the polymers to RFGD produced an oxidized hydrophilic surface, yet the roughness of the surface was unaltered by the relatively mild plasma conditions used. In this article, the frictional behavior of oxidized and unoxidized SR, PE, and FEP in distilled water, isotonic saline, and blood plasma environments is examined experimentally. The results are discussed in relation to the properties generally believed to affect frictional phenomena and to the surface properties as determined in part I. Results indicate that RFGD-treated SR generates less friction than untreated SR when dragged across all untreated and treated polymer surfaces, whether the medium is distilled water or an isotonic saline solution. Friction is consistently lower in a blood plasma medium between all surfaces investigated, most probably because of the presence of adsorbed proteins at the polymer interfaces.