scholarly journals Ultrastructural and Physicochemical Characterization of a Non-Crosslinked Type 1 Bovine Derived Collagen Membrane

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4135
Author(s):  
Igor da Silva Brum ◽  
Carlos Nelson Elias ◽  
Ana Lucia Rosa Nascimento ◽  
Cherley Borba Vieira de Andrade ◽  
Ronaldo Sergio de Biasi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Contact Angle ◽  
Physicochemical Characterization ◽  
Tensile Tests ◽  
Collagen Membrane ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Collagen Membranes

In this work, in vitro testing was used to study the properties of non-crosslinked type 1 bovine derived collagen membranes used in bone regeneration surgery. Collagen membranes were prepared, their surface roughness was quantified by interferometry, their morphology was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), their wettability was measured by the contact angle technique, their mechanical properties were investigated by tensile testing, their phase transformation temperatures were measured by Differential Scanning Calorimetry (DSC), and their biocompatibility was evaluated by immunological testing. The calorimetry tests showed that the membrane is formed only by type 1 collagen. The SEM observations showed that the morphology consists of layers of highly organized collagen fibers and patterns of striated fibrils typical of type 1 collagen. The small contact angle showed that the membrane is hydrophilic, with the possibility of rapid absorption of body fluids. The tensile tests showed that the membrane has enough elasticity, ductility, and mechanical strength for use in tissue regeneration. With the immunostaining technique, it was possible to confirm the membrane biocompatibility.

scholarly journals Preparation and characterization of baicalein loaded phytosomes: Assessment of in vitro parameters

2020 ◽  
Vol 12 (4) ◽  
pp. 22-29
Author(s):  
KanchanV Zade ◽  
Alok Pal Jain
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Herbal Extracts ◽  
Scanning Calorimetry ◽  
Reverse Phase ◽  
Tem Analysis ◽  
Transmission Electron

Phytosome is a complex between natural active ingredient and a phospholipid. Further, phytosomes been applied to many popular herbal extracts or active molecules for augmenting oral dissolution. Therefore, in present investigation, orally administered Baicalein, atype of flavanoids, is poorly absorbed, and shows suboptimal dissolution. The phytosomes encapsulating baicalein (1:1 Mm) were prepared by reverse phase evaporation method followed by lyophilization. Transmission electron microscopy (TEM) analysis revealed that phytosomes were almost spherical in shape with particle size below 100 nm. The Powder ex-ray diffraction (PXRD) and differential scanning calorimetry (DSC) demonstrated that Baicalein loaded phytosomes were amorphous in nature. Amorphization of therapeutic moiety leads to improvement in dissolution. In conclusion, epigallocatechin loaded phytosomes exhibited promising results and warrant further in vitro andin vivo investigations under a set of stringent parameters for transforming in to a clinically viable products.

Design, technological development and evaluation of stimuli-responsive chimeric nanocarriers for cancer therapy

2019 ◽  
Author(s):  
Νικόλαος Ναζίρης
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Technological Development ◽  
Stimuli Responsive ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Micro Dsc

Η επιστήμη έχει σημαντικά επιτεύγματα μέσω της Νανοτεχνολογίας, με εφαρμογές οι οποίες ξεπερνούν κατά πολύ τις δυνατότητες των συμβατικών μέσων σε πολλά επιστημονικά πεδία, συμπεριλαμβανομένης της Ιατρικής και της Φαρμακευτικής. Η Νανοϊατρική ευδοκιμεί μετά την ανάπτυξη των πρώτων νανοτεχνολογικών φαρμάκων στα τέλη του 20ου αιώνα και αναπτύχθηκε ώστε να αποτελεί μία από τις πιο υποσχόμενες προσπάθειες στον αγώνα κατά των ανθρωπίνων ασθενειών. Σε αυτό το πλαίσιο, τα λιποσώματα από καιρού αξιοποιούνται ως νανοτεχνολογικοί φορείς φαρμακομορίων και θεωρούνται ως μία από τις πιο καλώς μελετημένες πλατφόρμες για αυτόν τον σκοπό. Αυτοί οι νανοφορείς ομοιάζουν με τα κύτταρα και χαρακτηρίζονται από δομή και ιδιότητες στη μεσοκλίμακα τα οποία είναι δυναμικά, κυριαρχούμενα από το μηχανισμό και τους νόμους που διέπουν την αυτο-συναρμολόγηση. Η διαδικασία αυτή φέρει κρίσιμη σημασία για την ανάπτυξη νέων και καινοτόμων φαρμακευτικών προϊόντων, όπως και για τη νομοθετική ρύθμιση των ακολούθων “νανο-ομοειδών” φαρμάκων.Η παρούσα διδακτορική διατριβή πραγματεύεται το σύγχρονο θέμα των αποκρινόμενων σε ερεθίσματα χιμαιρικών/μικτών νανοφορέων για τη θεραπεία του καρκίνου, οι οποίοι ανήκουν στην τάξη των καινοτόμων νανοσυστημάτων μεταφοράς φαρμακομορίων για πολύπλοκες ασθένειες. Σκοπός της έρευνας ήταν ο ορθολογικός σχεδιασμός και η ανάπτυξη χιμαιρικών νανοσυστημάτων, οι οποίοι θα αποκρίνονται σε συγκεκριμένες φυσικές και φυσιολογικές συνθήκες, όπως αλλαγές στη θερμοκρασία και μεταβολές του pH, αλλά και η αξιολόγηση της συμπεριφοράς τους κατά την αυτο-συναρμολόγηση, των τελικών ιδιοτήτων τους και της in vitro και in vivo δράσης τους. Αυτά τα νανοσυστήματα αποτελούνται από δύο διαφορετικές τάξεις βιοϋλικών, ήτοι φωσφολιπίδια και αμφίφιλα δισυσταδικά συμπολυμερή και είναι υποσχόμενοι φαρμακοφορείς για τη θεραπεία διαφόρων τύπων καρκίνου, μεταφέροντας και απελευθερώνοντας θεραπευτικούς παράγοντες επιλεκτικά στο σημείο της νόσου.Τα αναλυτικά εργαλεία τα οποία χρησιμοποιήθηκαν για την αξιολόγηση των αλληλεπιδράσεων μεταξύ των βιοϋλικών και της αυτο-συναρμολογήσεώς τους συνεισφέρουν στην ανάπτυξη ποιοτικών νανοτεχνολογικών σκευασμάτων, προσφέροντας γνώση επί των ιδιοτήτων στη νανοκλίμακα αυτών των συστημάτων και της σχέσεις τους με τον τελικό νανοφορέα. Τα εργαλεία αυτά σχετίζονται με τη θερμοδυναμική, τις φυσικοχημικές ιδιότητες, τη σταθερότητα, τη μορφολογία, τη βιοφυσική και τη λειτουργικότητα και τελικώς, με τη βιολογική τοξικότητα και αποτελεσματικότητα των χιμαιρικών νανοσυστημάτων. Συγκεκριμένα, αυτά περιλαμβάνουν τη θερμική ανάλυση, όπως είναι η διαφορική θερμιδομετρία σαρώσεως (differential scanning calorimetry, DSC) ή η micro-DSC, τη σκέδαση φωτός, τεχνικές απεικονίσεως, όπως είναι η ηλεκτρονική μικροσκοπία διαπερατότητας (transmission electron microscopy, TEM) και η κρυογονική ηλεκτρονική μικροσκοπία μεταδόσεως διαπερατότητας (cryogenic TEM, cryo-TEM) και τέλος, βιολογικές δοκιμασίες, μέσω in vitro και in vivo μοντέλων. Ο πλήρης χαρακτηρισμός ενός νανοσυστήματος, όπως τα λιποσώματα, βάσει των εργαλείων αυτών, όχι μόνο συνδράμει στην ανάπτυξη καινοτόμων νανοσυστημάτων μεταφοράς φαρμακομορίων, αλλά και στην κατανόηση του ρόλου του κάθε μοριακού συστατικού του συστήματος και της διαδικασίας της αυτo-οργανώσεως στο τελικό φαρμακευτικό προϊόν.Τελικώς, η παρούσα διδακτορική έρευνα οδήγησε στην ανάπτυξη βιοσυμβατών και λειτουργικών χιμαιρικών νανοσυστημάτων, τα οποία είναι υποσχόμενα ως πλατφόρμες μεταφοράς φαρμακομορίων για καρκίνο, μέσω της αποκρινόμενης σε ερεθίσματα συμπεριφοράς τους. Η αξία της εγκαθιδρύσεως μιας λογικής για την αξιολόγηση των νανοσυστημάτων τέτοιου τύπου μέσω του συνδυασμού συγκεκριμένων και σημαντικών εργαλείων είναι επίσης εμφανής και θα προσφέρει γνώση για την περαιτέρω ανάπτυξη καινοτόμων φαρμάκων. Επιπλέον, θα συνδράμει και στη μελέτη και έγκριση των ακολούθων προϊόντων αυτών, τα οποία είναι γνωστά ως “νανο-ομοειδοί”. Τα εργαλεία αυτά αφορούν την αξιολόγηση του μηχανισμού της αυτο-συναρμολογήσεως και της σχέσης της με τις ιδιότητες, την τοξικότητα και τη λειτουργικότητα των καινοτόμων νανοσυστημάτων μεταφοράς φαρμακομορίων, με τελικό στόχο την ανάπτυξη ποιοτικών, ασφαλών και αποτελεσματικών καινοτόμων φαρμάκων για τη θεραπεία του καρκίνου.

Membranes of Chitosan and Collagen-Type 1 for Biomineralization/Ostheogenesis

2013 ◽  
Vol 587 ◽  
pp. 222-226
Author(s):  
Ricardo B. Pacheco ◽  
Marina Salvarani Tonoli ◽  
Marisa Masumi Beppu
Keyword(s):  
Collagen Type ◽  
Collagen Type I ◽  
Calcium Deposition ◽  
Collagen Membrane ◽  
Type I ◽  
Chitosan Membranes ◽  
Collagen Membranes ◽  
Collagen Type 1

The main objective of this work was to produce membranes of chitosan and collagen type I and check their ability to undergo “in vitro” calcification. The membranes of chitosan-collagen blends were characterized by TGA, infra-red spectroscopy and DSC. Samples of dense and porous membranes were immersed in solution SBF (Simulated Body Fluid) in order to verify their “in vitro” calcification. The membranes were observed by SEM. The production of chitosan-collagen membranes is possible, in dense and porous versions. We can conclude that the blend is less resistant to high temperatures, in comparison to pristine chitosan membranes shown in literature. Through the initial assays of calcification, we observe that it is possible to induce the calcium deposition on a chitosan-collagen membrane, as seen by SEM. Microscopy of fracture surfaces showed fibril structures, probably formed by collagen.

scholarly journals Indocyanine Green Loaded Polymeric Nanoparticles: Physicochemical Characterization and Interaction Studies with Caco-2 Cell Line by Light and Transmission Electron Microscopy

Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 133 ◽  
Author(s):  
Antonella Obinu ◽  
Elisabetta Gavini ◽  
Giovanna Rassu ◽  
Federica Riva ◽  
Alberto Calligaro ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Indocyanine Green ◽  
Antitumor Agents ◽  
Polymeric Nanoparticles ◽  
Physicochemical Characterization ◽  
Tem Analysis ◽  
Transmission Electron

Biomedical applications of nanoparticles (NPs) have reached an increasing development in recent years. Recently, we demonstrated that newly synthesized poly (ethyl 2-cyanoacrylate) nanoparticles (PECA-NPs) are possible antitumor agents due to their cytotoxicity for cancer cells. Indocyanine green (ICG), an amphiphilic tricarbocyanine fluorescent dye, is widely used for the detection of tumoral extension in different organs during clinical surgery. Moreover, this fluorescent agent is unstable and it has a rapid clearance in physiological conditions in vivo. In this study, ICG was charged in PECA-NPs to improve its aqueous stability and make easier its use for the identification of tumor cells. Microscopic and ultrastructural aspects concerning the related in vitro interactions between ICG-loaded NPs and tumor cell culture were investigated. Obtained results showed an effective stabilization of ICG; furthermore, color inclusions inside the cells treated with ICG-loaded NPs demonstrated the internalization of NPs with associated ICG. Transmission electron microscopy (TEM) analysis demonstrated the cytoplasmic presence of coated vesicles (Ø ≤ 100 nm), hypothesizing their involvement in the mechanism of endocytosis. Therefore, ICG-loaded NPs could be proposed as agents for tumor diagnosis, hypothesizing also in the future a specific therapeutic treatment.

scholarly journals FEATURES OF STRUCTURE FORMATION AND CHANGES IN THE MECHANICAL PROPERTIES OF CAST Al-Mg-Si-Mn ALLOY WITH THE ADDITION OF (Ti+Zr)

2015 ◽  
Vol 55 (4) ◽  
pp. 282 ◽  
Author(s):  
Oleksandr Trudonoshyn ◽  
Maxim Puchnin ◽  
Kostiantyn Mykhalenkov
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Ageing Time ◽  
Tensile Tests ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Scanning Electron

<p>The as-cast and heat-treated structure of permanent mould castings of AlMg<sub>5</sub>Si<sub>2</sub>Mn alloys with different contents of Ti has been investigated by differential scanning calorimetry, hardness and microhardness measurements, tensile tests and fractography analyses, scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray analysis. We have established that α-Al dendrites can be nucleated on an Al-Ti substrate, and also that primary Mg<sub>2</sub>Si crystals can be nucleated on oxides, including oxides of Al and Ti compounds. The dependence of the change in mechanical properties on ageing time, and on the amount of Ti in the alloys, is shown.</p>

Maytansine-Induced Mitotic Arrest in Human Lymphoblasts

1977 ◽  
Vol 35 ◽  
pp. 460-461
Author(s):  
Tai-Te Chao ◽  
John Sullivan ◽  
Awtar Krishan
Keyword(s):  
Electron Microscopy ◽  
Cell Cycle ◽  
Transmission Electron Microscopy ◽  
Tubulin Polymerization ◽  
Vinca Alkaloids ◽  
Antimitotic Activity ◽  
Transmission Electron ◽  
Flow Microfluorometry ◽  
Brain Tubulin

Maytansine, a novel ansa macrolide (1), has potent anti-tumor and antimitotic activity (2, 3). It blocks cell cycle traverse in mitosis with resultant accumulation of metaphase cells (4). Inhibition of brain tubulin polymerization in vitro by maytansine has also been reported (3). The C-mitotic effect of this drug is similar to that of the well known Vinca- alkaloids, vinblastine and vincristine. This study was carried out to examine the effects of maytansine on the cell cycle traverse and the fine struc- I ture of human lymphoblasts.Log-phase cultures of CCRF-CEM human lymphoblasts were exposed to maytansine concentrations from 10-6 M to 10-10 M for 18 hrs. Aliquots of cells were removed for cell cycle analysis by flow microfluorometry (FMF) (5) and also processed for transmission electron microscopy (TEM). FMF analysis of cells treated with 10-8 M maytansine showed a reduction in the number of G1 cells and a corresponding build-up of cells with G2/M DNA content.

Correlation Between Cellular Functions and Morphological Changes of Human Trophoblast in Vitro

1975 ◽  
Vol 33 ◽  
pp. 600-601
Author(s):  
John C. Garancis ◽  
Robert O. Hussa ◽  
Michael T. Story ◽  
Donald Yorde ◽  
Roland A. Pattillo
Keyword(s):  
Electron Microscopy ◽  
Cellular Proliferation ◽  
Morphological Changes ◽  
Culture Fluid ◽  
Cellular Functions ◽  
Human Trophoblast ◽  
Transmission Electron ◽  
Marked Activity ◽  
Malignant Trophoblast

Human malignant trophoblast cells in continuous culture were incubated for 3 days in medium containing 1 mM N6-O2'-dibutyryl cyclic adenosine 3':5'-monophosphate (dibutyryl cyclic AMP) and 1 mM theophylline. The culture fluid was replenished daily. Stimulated cultures secreted many times more chorionic gonadotropin and estrogens than did control cultures in the absence of increased cellular proliferation. Scanning electron microscopy revealed remarkable surface changes of stimulated cells. Control cells (not stimulated) were smooth or provided with varying numbers of microvilli (Fig. 1). The latter, usually, were short and thin. The surface features of stimulated cells were considerably different. There was marked increase of microvilli which appeared elongated and thick. Many cells were covered with confluent polypoid projections (Fig. 2). Transmission electron microscopy demonstrated marked activity of cytoplasmic organelles. Mitochondria were increased in number and size; some giant forms with numerous cristae were observed.

scholarly journals Ethosomes and Transethosomes for Mangiferin Transdermal Delivery

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 768
Author(s):  
Maddalena Sguizzato ◽  
Francesca Ferrara ◽  
Supandeep Singh Hallan ◽  
Anna Baldisserotto ◽  
Markus Drechsler ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Radical Scavenging ◽  
Human Keratinocytes ◽  
Antioxidant Response ◽  
Correlation Spectroscopy ◽  
Inflammatory Status ◽  
Transmission Electron ◽  
Anti Inflammatory

Mangiferin is a natural glucosyl xanthone with antioxidant and anti-inflammatory activity, making it suitable for protection against cutaneous diseases. In this study ethosomes and transethosomes were designed as topical delivery systems for mangiferin. A preformulation study was conducted using different surfactants in association with phosphatidylcholine. Vesicle dimensional distribution was monitored by photon correlation spectroscopy, while antioxidant capacity and cytotoxicity were respectively assessed by free radical scavenging analysis and MTT on HaCaT keratinocytes. Selected nanosystems were further investigated by cryogenic transmission electron microscopy, while mangiferin entrapment capacity was evaluated by ultracentrifugation and HPLC. The diffusion kinetics of mangiferin from ethosomes and transethosomes evaluated by Franz cell was faster in the case of transethosomes. The suitability of mangiferin-containing nanovesicles in the treatment of skin disorders related to pollutants was investigated, evaluating, in vitro, the antioxidant and anti-inflammatory effect of ethosomes and transethosomes on human keratinocytes exposed to cigarette smoke as an oxidative and inflammatory challenger. The ability to induce an antioxidant response (HO-1) and anti-inflammatory status (IL-6 and NF-kB) was determined by RT-PCR and immunofluorescence. The data demonstrated the effectiveness of mangiferin loaded in nanosystems to protect cells from damage. Finally, to gain insight into the keratinocytes’ uptake of ethosome and transethosome, transmission electron microscopy analyses were conducted, showing that both nanosystems were able to pass intact within the cells.

scholarly journals Study on Structure, Thermal Behavior, and Viscoelastic Properties of Nanodiamond-Reinforced Poly (vinyl alcohol) Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1426
Author(s):  
Tomáš Remiš ◽  
Petr Bělský ◽  
Tomáš Kovářík ◽  
Jaroslav Kadlec ◽  
Mina Ghafouri Azar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Analysis ◽  
Single Step ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Primary Particles ◽  
Solution Casting Method ◽  
Average Size

In this work, advanced polymer nanocomposites comprising of polyvinyl alcohol (PVA) and nanodiamonds (NDs) were developed using a single-step solution-casting method. The properties of the prepared PVA/NDs nanocomposites were investigated using Raman spectroscopy, small- and wide-angle X-ray scattering (SAXS/WAXS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). It was revealed that the tensile strength improved dramatically with increasing ND content in the PVA matrix, suggesting a strong interaction between the NDs and the PVA. SEM, TEM, and SAXS showed that NDs were present in the form of agglomerates with an average size of ~60 nm with primary particles of diameter ~5 nm. These results showed that NDs could act as a good nanofiller for PVA in terms of improving its stability and mechanical properties.

scholarly journals Facile synthesis of Au/ZnO/Ag nanoparticles using Glechoma hederacea L. extract, and their activity against leukemia

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Renata Dobrucka ◽  
Aleksandra Romaniuk-Drapała ◽  
Mariusz Kaczmarek
Keyword(s):  
Electron Microscopy ◽  
Ag Nanoparticles ◽  
Mononuclear Cells ◽  
Leukemia Cell ◽  
Leukemia Cell Line ◽  
Mtt Test ◽  
Transmission Electron ◽  
Almost All ◽  
Glechoma Hederacea

AbstractMetal combinations have been attracting the attention of scientists for some time. They usually exhibit new characteristics that are different from the ones possessed by their components. In this work, Au/ZnO/Ag nanoparticles were synthesized biologically using Glechoma hederacea L. extract. The synthesized Au/ZnO/Ag nanoparticles were characterized by UV-Vis, Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and Atomic Force Microscopy (AFM). The microscopic methods confirmed the presence of spherical nanoparticles of 50–70 nm. The influence of biologically synthesized Au/ZnO/Ag nanoparticles on the vitality of human cells was evaluated in vitro with the use of established human Acute T Cell Leukemia cell line, Jurkat (ATCC® TIB-152™), as well as mononuclear cells isolated from peripheral blood (PBMC) of voluntary donors. Cell survival and the half-maximal inhibitory concentration index (IC50) were analyzed by the MTT test. The studies showed that the total loss of cell viability occurred at the Au/ZnO/Ag nanoparticle concentration range of 10 µmol–50 µmol. The use of Au/ZnO/Ag nanoparticles at the concentration of 100 µmol eliminated almost all living cells from the culture in 24h. The above observation confirms the result obtained during the MTT test.

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