Biophysical methods for quality evaluation of decellularized and recellularized tissue-engineered constructs of organs and tissues

Tissue engineering is rapidly growing now and can become a promising alternative to transplantation of organs and tissues,as it is devoid of major shortcomings of transplantology, such as acute shortage, complexity of selection, delivery andstorage of donor material, lifelong immunosuppressive therapy. One of the most widely known methods of obtainingbiological scaffolds for the subsequent creation of tissue-engineered constructs of organs and tissues is decellularization.The evaluation of the quality of the obtained scaffolds, based on the study of the viability of cell structures in decellularizedand recellularized matrices, is one of the priorities of modern regenerative medicine worldwide. In this investigation, thebiophysical criteria of decellularization and recellularization of tissue-engineered constructs based on the evaluation of thegeneration of free radicals in native, decellularized and recellularized tissues by EPR spectroscopy and chemoluminescencein a complex assessment of the quality of biological matrixes obtained are considered using intrathoracic organs and tissuesof rats. It has been established that the intensity indices of free radical generation in native and recellularized tissues ofanimal organs, as well as in decellularized matrices, can serve as one of the express criteria for quantitative assessment ofcell structures viability

Platelet membrane-based and tumor-associated platelettargeted drug delivery systems for cancer therapy / 医学前沿

Platelets have long been known to play critical roles in hemostasis by clumping and clotting blood vessel injuries. Recent experimental evidence strongly indicates that platelets can also interact with tumor cells by direct binding or secreting cytokines. For example, platelets have been shown to protect circulating cancer cells in blood circulation and to promote tumor metastasis. In-depth understanding of the role of platelets in cancer progression and metastasis provides promising approaches for platelet biomimetic drug delivery systems and functional platelet-targeting strategies for effective cancer treatment. This review highlights recent progresses in platelet membrane-based drug delivery and unique strategies that target tumor-associated platelets for cancer therapy. The paper also discusses future development opportunities and challenges encountered for clinical translation.

Arrestins: structural disorder creates rich functionality

Arrestins are soluble relatively small 44-46 kDa proteins that specifically bind hundreds of active phosphorylated GPCRs and dozens of non-receptor partners. There are binding partners that demonstrate preference for each of the known arrestin conformations: free, receptor-bound, and microtubule-bound. Recent evidence suggests that conformational flexibility in every functional state is the defining characteristic of arrestins. Flexibility, or plasticity, of proteins is often described as structural disorder, in contrast to the fixed conformational order observed in high-resolution crystal structures. However, protein-protein interactions often involve highly flexible elements that can assume many distinct conformations upon binding to different partners. Existing evidence suggests that arrestins are no exception to this rule: their flexibility is necessary for functional versatility. The data on arrestins and many other multi-functional proteins indicate that in many cases, "order" might be artificially imposed by highly non-physiological crystallization conditions and/or crystal packing forces. In contrast, conformational flexibility (and its extreme case, intrinsic disorder) is a more natural state of proteins, representing true biological order that underlies their physiologically relevant functions.

Radiolytic studies of cefozopran hydrochloride in the solid state

Background: The radiation sterilization is one of the best methods for sterilizing vulnerable degradation drugs like cefozopran hydrochloride. Results: Chemical stability of radiosterylized cefozopran hydrochloride, was confirmed by spectrophotometric and chromatographic methods. EPR studies showed that radiation has created some radical defects whose concentration was no more than several dozen ppm. The antibacterial activity of cefozopran hydrochloride irradiated with a dose of 25 kGy was unaltered for Gram-positive bacteria but changed for two Gram-negative strains. The radiation sterilized cefozopran hydrochloride was not in vitro cytotoxic against human CCD39Lu normal lung fibroblast cell line. Conclusions: Cefozopran hydrochloride in solid state is not resistant to radiation sterilization and this method cannot be used for sterilization of this compound.

Synthesis, spectroscopic characterization and biological applications of Cu(II) and Ni(II) complexes with 2-butyl-4-chloro-5-formylimidazole thiosemicarbazone.

Cu(II) and Ni(II) complexes of 2-butyl-4-chloro-5-formylimidazole thiosemicarbazone (L) are synthesized and characterized by using spectroscopic techniques like elemental analysis, FT-IR, mass spectrometry, electronic and EPR spectra. The complexes are found to have characteristic electronic spectra and the geometry of the complexes are identified as octahedron. Both the complexes are found to exhibit similar anti-microbial activity against the gram –ve and gram +ve bacteria. Anti-cancer activity against the cancer cell lines (MDA-MB 231 cell lines) among the compounds studied for % of viability, the inhibition concentration 50 values were shown by Cu(II)-L complex at 80 mg/ml and by Ni(II)-L complex at 100 mg/ml.

Synthesis, spectral aspects and biological activities of 5-hydroxy-2-nitrobenzaldehydethiosemicarbazone and their Mn(II), Co(II) and Ni(II) complexes.

The ligation behavior of 5-hydroxy-2-nitrobenzaldehydethiosemicarbazone (L) and its Mn(II), Co(II) and Ni(II) complexes has been synthesized and characterized by Elemental analysis, Electronic, FT-IR, Raman, EPR spectral techniques and Cyclic voltammetric study. The ligand (L) belongs to triclinic system with P1 space group. The IR spectral data of ligand indicate the taking part of sulphur and azomethine nitrogen in coordination to the central metal ion. The electronic, FT-IR and EPR spectral studies reveals all the complexes are distorted octahedral geometry. The synthesized ligand and its metal(II) complexes were tested for their antioxidant activity by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method and antibacterial activity against E.coli, Staphylococcus aureus, Bacillus subtilis, Salmonella typhi and Klebsiella pneumonia. The antibacterial and antioxidant activities of the ligand and its metal complexes had shown moderate to good activity, among all the compounds Ni(II) complex had shown more activity.

Characterization and biological activities of extracellular melanin produced by Schizophyllum commune (Fries).

Melanins are enigmatic pigments produced by a wide variety of microorganisms including bacteria and fungi. Here, we have isolated and characterized extracellular melanin from mushroom fungus, Schizophyllum commune. The extracellular dark pigment produced by the broth culture of S. commune, after 21 days of incubation was recovered by hot acid-alkali treatment. The melanin nature of the pigment was characterized by biochemical tests and further, confirmed by UV, IR, EPR, NMR and MALDI-TOF Mass Spectra. Extracellular melanin, at 100 µg/ml, showed significant antibacterial activity against Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae and Pseudomonas fluorescens and antifungal activity against Trichophyton simii and T. rubrum. At a concentration of 50 µg/ml, melanin showed high free radical scavenging activity of DPPH (2,2-diphenyl-1-picrylhydrazyl) indicating its antioxidant potential. It showed concentration dependent inhibition of cell proliferation of Human Epidermoid Larynx Carcinoma Cell Line (HEP-2). This study has demonstrated characterization of melanin from basidiomycetes mushroom fungus, Schizophyllum commune and its applications.

Synthesis, spectroscopic characterization and antimicrobial activity studies of 2-Butyl-4-chloro-5-formylimidazole thiosemicarbazone and its manganese (II) complex.

A novel chelating tridentate organic ligand, 2-Butyl-4-chloro-5-formylimidazole thiosemicarbazone(L) is synthesized and characterized by using spectroscopic techniques like elemental analysis, FT-IR, 1H and 13C NMR, UV-vis and Mass spectrometry. The free ligand is then used for the synthesis of Mn(II) complex thoroughly characterized by FT-IR, EPR and electronic spectral analysis. The complex is found to have characteristic d5 electronic spectrum and the geometry of the complex is identified as octahedron based on the g value obtained from the EPR spectrum. Both the ligand and Mn(II)L2 compounds are found to exhibit similar antimicrobial activity against the gram –ve and gram +ve bacteria.

Spo0A positively regulates epr expression by negating the repressive effect of co-repressors, SinR and ScoC, in Bacillus subtilis.

Bacillus subtilis under nutritional deprivation exhibits several physiological responses such as synthesis of degradative enzymes, motility, competence, sporulation, etc. At the onset of post-exponential phase the global response regulator, Spo0A, directly or indirectly activates the expression of genes involved in the above processes. These genes are repressed during the exponential phase by a group of proteins called transition state regulators, e.g. AbrB, ScoC and SinR. One such post-exponentially expressed gene is epr, which encodes a minor extracellular serine protease and is involved in the swarming motility of B. subtilis. Deletion studies of the upstream region of epr promoter revealed that epr is co-repressed by transition state regulators, SinR and ScoC. Our study shows that Spo0A positively regulates epr expression by nullifying the repressive effect of co-repressors, SinR and ScoC. We demonstrate via in vitro mobility shift assays that Spo0A binds to the upstream region of epr promoter and in turn occludes the binding site of one of the co-repressor, SinR. This explains the mechanism behind the positive regulatory effect of Spo0A on epr expression.

Application Prospect of EPR System in Total Cost Accounting of Hospitals / 中国卫生经济

The cost accounting plays central role in enhancing financial management in the hospital. With the increasing hospital competition, conventional model of cost accounting is changing, and gradually replaced with a novel model of cost accounting-total cost accounting. With the wide spread of total cost accounting in all hospitals, it is found that the general operation of hospitals is limited by the original HIS information system. EPR system feathered with the advanced data administration and potent function of financial analysis holding promise in adoption and acceptance by hospitals, serving as information collector and analyzer following HIS system.

Anti-thrombus activity of a novel anti-thrombus protein EPR-hirudin / 中国药学杂志

OBJECTIVE: To evaluate the anti-thrombus activitity of EPR-hirudin (EH), a derivative of hirudin obtained by adding three amino acids at the nitrogen terminus. METHODS: The anti-thrombus activitity of EH was investigated by chromophore substrate method in vitro as well as by rat models of carotid arterial thrombosis and inferior vena cava thrombosis in vivo. RESULTS: The result of anti-thrombin experiment in vitro showed that EH did not produced anti-thrombin activity unless it was cleaved by blood coagulation factors. Then the anti-thrombus feature of EH was confirmed in vivo separately in the rat models of carotid arterial thrombosis and inferior vena cava thrombosis. The formation of arterial clot was inhibited and the weight of venous clot was decreased after administration of EH in a dose-independent manner. However, the blooding time, activated partial thromboplastin time (APTT) and thrombin time (TT) did not significantly increase in EH groups compared with HV and low molecular heparin. CONCLUSION: EPR-hirudin can inhibit the formation of arterial and venous clot and has low risk of blooding.

Elaboración de dosímetros de alanina y sus posibles aplicaciones en riesgos profesionales / Elaboração de dosímetros de alanina e suas possíveis aplicações em riscos profissionais / Elaboration of alanine dosimeters and their possible applications in professional risks

Desarrollar dosímetros de alanina y alanina/parafina con miras a atender la creciente utilización de la radiación ionizante a nivel tecnológico. Materiales y métodos. Los radicales libres producidos por la radiación ionizante en la alanina se detectan por resonancia magnética electrónica (ESR); la parafina se utiliza como aglutinante. La metodología de preparación incluye: elaboración, irradiación, lectura y análisis de datos para los dos tipos de dosímetros. Los espectros ESR estudiados corresponden a dosímetros de alanina con masas entre 60 y 120 mg e irradiados con dosis de 10 y 20 Gy, y dosímetros de alanina/parafina de 160 mg e irradiados con diferentes dosis en un haz de fotones de 4 MV. Resultados. La intensidad de los espectros (las cinco líneas características) depende de las dosis recibidas por los dosímetros y su relación es lineal. Con alanina pura y una dosis de 10 Gy la mínima cantidad requerida fue 120 mg; la compactación del cilindro lograda no fue suficiente para evitar la fragmentación parcial del dosímetro. La parafina no tiene señal paramagnética; en los dosímetros de alanina/parafina (cilindros de longitud 13 mm y diámetro 3.5 mm, en la relación 80:20, y buena dureza) se estudió la respuesta señal ESR-dosis en un rango entre 20 y 120 Gy. Conclusiones. Los cilindros de alanina/parafina fabricados tienen una dureza apropiada para ser manipulados como dosímetros de radiación ionizante; su reproducibilidad y la efectividad en la acumulación de dosis es buena...

Elaboration of alanine dosimeters and their possible applications in professional risks. Objective. To develop dosimeters of alanine and alanine/paraffin in order to meet the growing use of ionizing radiation at the technological level. Materials and methods. Free radicals produced by ionizing radiation in alanine are detected by electron spin resonance (ESR); paraffin is used as binder. The methodology ofpreparation includes: elaboration, irradiation, data collection and data analysis for the two types of dosimeters. The ESR spectra studied correspond to alanine dosimeters with masses between 60 and 120 mg and irradiated with doses of 10 and 20 Gy, and alanine/paraffin dosimeters with 160 mg and irradiated with different doses in a beam of photons 4 MV. Results. The intensity of the spectra (thecharacteristic five lines) depends on the doses received by the dosimeters and their relationship is linear. With pure alanine and a dose of 10 Gy, the minimum amount required was 120 mg; the achieved cylinder compaction was not sufficient to avoid the partial fragmentation of the dosimeter. Paraffin has no paramagnetic signal; in the alanine/paraffin dosimeters (cylinders of 13 mm in length and 3.5 mm of diameter, with a ratio 80:20, and good hardness) the response signal ESR-dose was studied in a range between 20 and 120 Gy. Conclusions. The cylinders of alanine/paraffin manufactured have an appropriate hardness to be handled as dosimeters of ionizing radiation; their reproducibility and effectiveness in the accumulation of dose is good...

Elaboração de dosímetros de alanina e suas possíveis aplicações em riscos profissionais. Objetivo. Desenvolver dosímetros de alanina e alanina/parafina com a finalidade de satisfazer a crescente utilização de radiações ionizantes ao nível tecnológico. Materiais e métodos. Os radicais livres produzidos pela radiação ionizante na alanina são detectados por ressonância magnética eletrônica (EPR); a parafina é utilizada como aglutinante. O método de preparação inclui: elaboração, irradiação, leitura e analise dos dados para os dois tiposde dosímetros. Os espectros ESR estudados correspondem a dosímetros de alanina com massas entre 60 e 120 mg e irradiados com doses de 10 e 20 Gy, e dosímetros de alanina/parafina de 160 mg e irradiados com diferentes doses de um feixe de fótons de 4 MV. Resultados.A intensidade dos espectros (as cinco linhas características) depende das doses recebidas pelos dosímetros e sua relação é linear. Com lanina pura e uma dose de 10 Gy a mínima quantidade requerida foi de 120 mg; a compactação do cilindro alcançada não foi suficiente para evitar a fragmentação parcial do dosímetro. A parafina não tem sinal paramagnético; nos dosímetros de alanina/parafina (cilindros de 13 mmde comprimento e 3,5 mm de diâmetro, na proporção 80:20 e boa dureza) foi estudada a resposta a sinal ESR-dose em um intervalo entre 20 e 120 Gy. Conclusões. Os cilindros de alanina/parafina fabricados têm uma dureza adequada para ser tratados como dosímetros de radiação ionizante; sua reprodutibilidade e eficiência no acúmulo de dose é bom...

Antioxidant Effects of Munziq and Mushil of Abnormal Savda by Electron Paramagnetic Resonance / 中药新药与临床药理

To explore the antioxidant mechanism of munziq and mushil of Abnormal Savda. Scavenging effects of munziq and mushil of Abnormal Savda on superoxide anion radical(O -? 2) and hydroxyl radical (OH ?) were measured by electron paramagnetic resonance(EPR). Munziq and mushil possessed obvious scavenging effects on O -? 2 and OH ? and the effect of mushil was superior to that of the munziq.[Conclusion] The EPR is a reliable, effective, accurate, sensitive method for measuring the antioxidant properties of herbal medicines. Munziq and mushil are two kinds of effective antioxidants, and the antioxidant effect may be one of the therapeutic mechanisms of munziq and mushil.