scholarly journals Conjugates of Chitosan and Calcium Alginate with Oligoproline and Oligohydroxyproline Derivatives for Potential Use in Regenerative Medicine

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3079
Author(s):  
Joanna Wasko ◽  
Justyna Fraczyk ◽  
Angelika Becht ◽  
Zbigniew J. Kaminski ◽  
Sandra Flinčec Grgac ◽  
...  

New materials that are as similar as possible in terms of structure and biology to the extracellular matrix (external environment) of cells are of great interest for regenerative medicine. Oligoproline and oligohydroxyproline derivatives (peptides 2–5) are potential mimetics of collagen fragments. Peptides 2–5 have been shown to be similar to the model collagen fragment (H-Gly-Hyp-Pro-Ala-Hyp-Pro-OH, 1) in terms of both their spatial structure and biological activity. In this study, peptides 2–5 were covalently bound to nonwovens based on chitosan and calcium alginate. Incorporation of the peptides was confirmed by Fourier transform -infrared (FT-IR) and zeta potential measurements. Biological studies (cell metabolic activity by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test and Live/Dead assay) proved that the obtained peptide-polysaccharide conjugates were not toxic to the endothelial cell line EA.hy 926. In many cases, the conjugates had a highly affirmative influence on cell proliferation. The results of this study show that conjugates of chitosan and calcium alginate with oligoproline and oligohydroxyproline derivatives have potential for use in regenerative medicine.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1604
Author(s):  
Yiqun Dai ◽  
Xiaolong Sun ◽  
Bohan Li ◽  
Hui Ma ◽  
Pingping Wu ◽  
...  

Nasopharyngeal carcinoma (NPC) is a common malignant head and neck tumor. Drug resistance and distant metastasis are the predominant cause of treatment failure in NPC patients. Hispidulin is a flavonoid extracted from the bioassay-guided separation of the EtOH extract of Salvia plebeia with strong anti-proliferative activity in nasopharyngeal carcinoma cells (CNE-2Z). In this study, the effects of hispidulin on proliferation, invasion, migration, and apoptosis were investigated in CNE-2Z cells. The [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay and the colony formation assay revealed that hispidulin could inhibit CNE-2Z cell proliferation. Hispidulin (25, 50, 100 μM) also induced apoptosis in a dose-dependent manner in CNE-2Z cells. The expression of Akt was reduced, and the expression of the ratio of Bax/Bcl-2 was increased. In addition, scratch wound and transwell assays proved that hispidulin (6.25, 12.5, 25 μM) could inhibited the migration and invasion in CNE-2Z cells. The expressions of HIF-1α, MMP-9, and MMP-2 were decreased, while the MMPs inhibitor TIMP1 was enhanced by hispidulin. Moreover, hispidulin exhibited potent suppression tumor growth and low toxicity in CNE-2Z cancer-bearing mice at a dosage of 20 mg/kg/day. Thus, hispidulin appears to be a potentially effective agent for NPC treatment.



2021 ◽  
Vol 22 (8) ◽  
pp. 4018
Author(s):  
Anna Masek ◽  
Angelika Plota

In the field of polymer technology, a variety of mainly synthetic additives are used to stabilize the materials during processing. However, natural compounds of plant origin can be a green alternative to chemicals such as synthetic polyphenols. An analysis of the effect of hesperidin on the aging behavior of ethylene-norbornene copolymer was performed. The evaluation of changes in the tested samples was possible by applying the following tests: determination of the surface energy and OIT values, mechanical properties analysis, colour change measurements, FT-IR and TGA analyses. The obtained results proved that hesperidin can be effectively used as natural stabilizer for polymers. Furthermore, as a result of this compound addition to Topas-silica composites, their surface and physico-mechanical properties have been improved and the resistance to aging significantly increased. Additionally, hesperidin can act as a dye or colour indicator and only few scientific reports describe a possibility of using flavonoids to detect changes in products during their service life, e.g., in food packaging. In the available literature, there is no information about the potential use of hesperidin as a stabilizer for cycloolefin copolymers. Therefore, this approach may contribute not only to the current state of knowledge, but also presents an eco-friendly solution that can be a good alternative to synthetic stabilizers.



2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Sospeter N. Njeru ◽  
Jackson M. Muema

Abstract Objectives We and others have shown that Aspilia pluriseta is associated with various biological activities. However, there is a lack of information on its cytotoxicity. This has created an information gap about the safety of A. pluriseta extracts. As an extension to our recent publication on the antimicrobial activity and the phytochemical characterization of A. pluriseta root extracts, here we report on cytotoxicity of tested solvent fractions. We evaluated the potential cytotoxicity of these root extract fractions on Vero cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results We show that all solvent extract fractions (except methanolic solvent fractions) had cytotoxic concentration values that killed 50% of the Vero cells (CC50) greater than 20 µg/mL and selectivity index (SI) greater than 1.0. Taken together, we demonstrate that, A. pluriseta extract fractions’ earlier reported bioactivities are within the acceptable cytotoxicity and selective index limits. This finding scientifically validates the potential use of A. pluriseta in the discovery of safe therapeutics agents.



2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Simone Cristina Picchi ◽  
Mariana de Souza e Silva ◽  
Luiz Leonardo Saldanha ◽  
Henrique Ferreira ◽  
Marco Aurélio Takita ◽  
...  

AbstractN-Acetylcysteine (NAC) is an antioxidant, anti-adhesive, and antimicrobial compound. Even though there is much information regarding the role of NAC as an antioxidant and anti-adhesive agent, little is known about its antimicrobial activity. In order to assess its mode of action in bacterial cells, we investigated the metabolic responses triggered by NAC at neutral pH. As a model organism, we chose the Gram-negative plant pathogen Xanthomonas citri subsp. citri (X. citri), the causal agent of citrus canker disease, due to the potential use of NAC as a sustainable molecule against phytopathogens dissemination in citrus cultivated areas. In presence of NAC, cell proliferation was affected after 4 h, but damages to the cell membrane were observed only after 24 h. Targeted metabolite profiling analysis using GC–MS/TOF unravelled that NAC seems to be metabolized by the cells affecting cysteine metabolism. Intriguingly, glutamine, a marker for nitrogen status, was not detected among the cells treated with NAC. The absence of glutamine was followed by a decrease in the levels of the majority of the proteinogenic amino acids, suggesting that the reduced availability of amino acids affect protein synthesis and consequently cell proliferation.



2004 ◽  
Vol 836 ◽  
Author(s):  
S. Holger Eichhorn ◽  
Nicholas Fox ◽  
Bryan Bornais

AbstractPotentially n-type and p-type semi-conducting discotic liquid crystal dyes are linked together to star-shaped heptamers, which might self-organize into super-columns of separated p-type and n-type columnar stacks. Their synthesis, mesomorphism, and electronic properties will be discussed along with their potential use in photovoltaic devices.



2021 ◽  
Author(s):  
ABDELAZIZ IMGHARN ◽  
Nouh Aarab ◽  
Abdelghani Hsini ◽  
Yassine Naciri ◽  
Mohammed Elhoudi ◽  
...  

Abstract The aim of this work is to investigate the adsorption performance of orange G (OG) dye from aqueous solutions employing PANI@sawdust biocomposite enrobed by calcium-alginate biobeads (Alg-PANI@SD). The as-prepared adsorbent was characterized by scanning-electron-microscopy (SEM), X-ray energy dispersive spectroscopy (EDS) and Fourier transforms infrared (FT-IR) spectroscopy, and used to remove Orange G dye from water. batch tests were performed as a function of adsorbent dosage, pH, contact time, interfering ions and initial OG dye concentration. Experimental results show that the kinetic model of pseudo-first-order (PFO) and Freundlich isotherm provided a good fitting of the whole experimental data. The results revealed that the as-prepared tricomposite Alg-PANI@SD, has the potential to be applied as a low-cost adsorbent for the adsorption of OG dye from aqueous media.



2018 ◽  
Vol 205 (4) ◽  
pp. 189-196 ◽  
Author(s):  
Yu Feng ◽  
Xiang-Yang Tian ◽  
Peng Sun ◽  
Ze-Peng Cheng ◽  
Reng-Fei Shi

Mechanical stretch may cause myoblasts to either proliferate or undergo apoptosis. Identifying the molecular events that switch the fate of a stretched cell from proliferation to apoptosis is practically important in the field of regenerative medicine. A recent study on vascular smooth muscle cells illustrated that identification of these events may be achieved by addressing the stretch-induced opposite cellular outcomes simultaneously within a single investigation. To define conditions or a model in which both proliferation and apoptosis can be studied at the same time, we exposed in vitro cultured C2C12 myoblasts to a cyclic mechanical stretch regimen of 15% elongation at a stretching frequency of 1 Hz for 0, 2, 4, 6, or 8 h every day, consecutively, for 3 days. Both proliferation and apoptosis were observed. Moreover, as the duration of the stretch was prolonged, cell proliferation increased until it peaked at the optimal stretching duration. Afterwards, apoptosis gradually prevailed. Therefore, we established a model in which stretch-induced cell proliferation and apoptosis can be studied simultaneously.



Author(s):  
Shamo Zokhrab Tapdiqov

Doxycycline was loaded with synthesized micelles composed of methyl Poly (ethylene glycol-block-poly (L-alanine–co–L-aspartate), or mPEG–Ala–Asp, and then characterized as a drug delivery carrier. The synthesis of the temperature-sensitive mPEG–Ala–Asp block copolymer was carried out by two-step ring-opening polymerization: firstly, the mPEG reacts with L-alanine N-carboxylic anhydride, and secondly the resulting mPEG–Ala reacts with benzyl aspartate N-carboxylic anhydride. The molecular structure of the copolymers obtained was determined by FT-IR and NMR spectroscopy methods and the micelles were characterized by SEM, TEM and DLS, respectively. The controlled release of Dox from hydrogel in the presence of PBS (8 to 9% by weight) lasts 6 to 7 days exhibiting stable release rates. The drug release mechanisms were studied: Higuchi and zero order models. The results and correlation coefficients applied to the Higuchi and zero-order models. The findings show the potential use of mPEG–Ala–Asp as an effective depot matrix to deliver anthracycline class drugs.



2019 ◽  
Vol 42 (1) ◽  
pp. 94-101
Author(s):  
Nur Adibah Mohd Amin ◽  
Rusnah Syahila Duali Hussen ◽  
See Mun Lee ◽  
Kae Shin Sim ◽  
Suerialoasan Navanesan

Abstract Two new diorganotin(IV) complexes with the general formula (RC7H6)2Sn(L) (where RC7H6 = p-ClBn, C1; and p-FBn, C2) were prepared based on the reaction of 2,3-bis(4-hydroxysalicylidene-amino)-maleic nitrile (L) with substituted dibenzyltin(IV) dichloride. The structures were confirmed by elemental analysis, Fourier transform infrared (FT-IR), proton and carbon nuclear magnetic resonance (1H and 13C NMR). They were tested against several cancer cell lines by using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. C1, which was most effective against MCF-7 breast cancer cell line, was further investigated in formulation and encapsulation studies, including drug encapsulation efficiency, particle size, morphology and in vitro drug release. An encapsulation of about 90% was achieved with particles of 128 nm average diameter. Field emission scanning electron microscopy (FESEM) confirmed a spherical shape for the encapsulated C1. The cumulative drug release over a period of 60 days in phosphate buffered saline (PBS) at pH 7.4 was 75%. Based on these results, the formulated drug has the potential of a slow release drug for cancer chemotherapy.



2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Wei Xiong ◽  
Yue-kun Shen ◽  
Peng Dong ◽  
Ying Xiao ◽  
Xiong-qing Huang ◽  
...  

Sustained release of anesthesia has shown great promise in the treatment of chronic pain in patients. In this research, we used neutralized ropivacaine as an anesthesia and poly(ε-caprolactone) (PCL) with different architectures to systematically study how these architectures affect the release of ropivacaine. After optimizing the parameters of the preparation of microspheres, ropivacaine-loaded 1-PCL microspheres and 4-PCL microspheres were obtained. Fourier Transform infrared spectra (FT-IR) and X-ray diffraction spectra (XRD) confirmed that ropivacaine was encapsulated within the microsphere rather than inserted on the surface of the microsphere. Ropivacaine was found to be buried deeper in the 1-PCL microsphere than in the 4-PCL microsphere. In vitro release assay revealed that small crystalline grains interfered with ropivacaine release in 4-PCL microspheres during the initial release period, but then two kinds of microspheres showed a similar ropivacaine release rate. We basically proved that the architecture of PCL has a negligible effect on ropivacaine release. Cell proliferation test revealed that the release of products from the microspheres resulted in insignificant toxicity towards mammalian cells.



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