scholarly journals Photoinduced Porcine Gelatin Cross-Linking by Homobi- and Homotrifunctional Tetrazoles

Gels ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 124
Author(s):  
Luca Vaghi ◽  
Mauro Monti ◽  
Marcello Marelli ◽  
Elisa Motto ◽  
Antonio Papagni ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Amino Acid ◽  
Cross Linking ◽  
Natural Origin ◽  
Physiological Conditions ◽  
Biomaterial Scaffold ◽  
Amino Acid Side Chains ◽  
Improved Stability ◽  
First Time

Gelatin is a costless polypeptide material of natural origin, able to form hydrogels that are potentially useful in biomaterial scaffold design for drug delivery, cell cultures, and tissue engineering. However, gelatin hydrogels are unstable at physiological conditions, losing their features only after a few minutes at 37 °C. Accordingly, treatments to address this issue are of great interest. In the present work, we propose for the first time the use of bi- and trifunctional tetrazoles, most of them unknown to date, for photoinduced gelatin cross-linking towards the production of physiologically stable hydrogels. Indeed, after UV-B irradiation, aryl tetrazoles generate a nitrilimine intermediate that is reactive towards different functionalities, some of them constitutively present in the amino acid side chains of gelatin. The efficacy of the treatment strictly depends on the structure of the cross-linking agent used, and substantial improved stability was observed by switching from bifunctional to trifunctional cross-linkers.

Polycaprolactone(PCL)/Gelati(Ge)-Based Electrospun Nanofibers for Tissue Engineering and Drug Delivery Application

2014 ◽  
Vol 554 ◽  
pp. 57-61 ◽  
Author(s):  
Lor Huai Chong ◽  
Mim Mim Lim ◽  
Naznin Sultana
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Electrospun Nanofibers ◽  
Processing Parameters ◽  
Natural Polymer ◽  
Electrospinning Technique ◽  
Minimum Concentration ◽  
Promising Alternative ◽  
Injured Tissue ◽  
Biomaterial Scaffold

Recent development of tissue engineering has been emphasized on tissue regeneration and repairing in order to solve the limitation of organ and tissue transplantation issues. Biomaterial scaffold, which plays an important role in this development, not only provides a promising alternative in order to improve the efficiency of cell transplantation in tissue engineering but also to deliver cells with growth factors and drugs into injured tissue to increase the survival of cell via drug delivery system. In this study, nanofibers were fabricated through blending of a synthetic polymer polycaprolactone (PCL) and a natural polymer Gelatin (Ge) using electrospinning technique. Processing parameters were optimized to determine the most suitable properties of PCL/Ge nanofibers. The surface morphology of PCL/Ge nanofibers were then characterized using Scanning Electron Microscopy (SEM). Six samples of nanofibers from different amount of gelatin mixed with 10% PCL (w/v) were successfully fabricated. Experimental results showed that 18kV of high voltage provided more homogenous and less beaded nanofibers. Meanwhile, the 0.8g of Ge in 10% PCL (w/v) was set as the maximum concentration while 0.2g of Ge in 10% PCL (w/v) was set as the minimum concentration to reduce the bead formation.

A study of the reactivity of S(VI)–F containing warheads with nucleophilic amino-acid side chains under physiological conditions

2017 ◽  
Vol 15 (45) ◽  
pp. 9685-9695 ◽  
Author(s):  
H. Mukherjee ◽  
J. Debreczeni ◽  
J. Breed ◽  
S. Tentarelli ◽  
B. Aquila ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Side Chains ◽  
Physiological Conditions ◽  
Amino Acid Side Chains

Profiling the reactivity and stability of SVI–F warheads towards nucleophilic amino acids for the development of biochemical probe compounds.

scholarly journals Template-assisted extrusion of biopolymer nanofibers under physiological conditions

2016 ◽  
Vol 8 (10) ◽  
pp. 1059-1066 ◽  
Author(s):  
Mohammad Raoufi ◽  
Neda Aslankoohi ◽  
Christine Mollenhauer ◽  
Heike Boehm ◽  
Joachim P. Spatz ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Biomedical Applications ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Physiological Conditions

Biomedical applications ranging from tissue engineering to drug delivery systems require versatile biomaterials based on the scalable and tunable production of biopolymer nanofibers under physiological conditions.

Freeze dried cross linking free biodegradable composites with microstructures for tissue engineering and drug delivery application

2013 ◽  
Vol 33 (1) ◽  
pp. 466-474 ◽  
Author(s):  
M.I. Ahymah Joshy ◽  
K. Elayaraja ◽  
N. Sakthivel ◽  
V. Sarath Chandra ◽  
G.M. Shanthini ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Cross Linking ◽  
Drug Delivery Application ◽  
Biodegradable Composites ◽  
Freeze Dried

scholarly journals Fully amino acid-based hydrogel as potential scaffold for cell culturing and drug delivery

2019 ◽  
Vol 10 ◽  
pp. 2579-2593 ◽  
Author(s):  
Dávid Juriga ◽  
Evelin Sipos ◽  
Orsolya Hegedűs ◽  
Gábor Varga ◽  
Miklós Zrínyi ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Amino Acid ◽  
Drug Release ◽  
Disulfide Bonds ◽  
Release Kinetics ◽  
Building Blocks ◽  
Periodontal Ligament Cells ◽  
Polymer Backbone ◽  
Model Drug

Polymer hydrogels are ideal scaffolds for both tissue engineering and drug delivery. A great advantage of poly(amino acid)-based hydrogels is their high similarity to natural proteins. However, their expensive and complicated synthesis often limits their application. The use of poly(aspartic acid) (PASP) seems an appropriate solution for this problem due to the relatively cheap and simple synthesis of PASP. Using amino acids not only as building blocks in the polymer backbone but also as cross-linkers can improve the biocompatibility and the biodegradability of the hydrogel. In this paper, PASP cross-linked with cystamine (CYS) and lysine-methylester (LYS) was introduced as fully amino acid-based polymer hydrogel. Gels were synthesized employing six different ratios of CYS and LYS. The pH dependent swelling degree and the concentration of the elastically active chain were determined. After reduction of the disulfide bonds of CYS, the presence of thiol side groups was also detected. To determine the concentration of the reactive cross-linkers in the hydrogels, a new method based on the examination of the swelling behavior was established. Using metoprolol as a model drug, cell proliferation and drug release kinetics were studied at different LYS contents and in the presence of thiol groups. The optimal ratio of cross-linkers for the proliferation of periodontal ligament cells was found to be 60−80% LYS and 20−40% CYS. The reductive conditions resulted in an increased drug release due to the cleavage of disulfide bridges in the hydrogels. Consequently, these hydrogels provide new possibilities in the fields of both tissue engineering and controlled drug delivery.

Diversity of Primary Structures of the Carboxy-terminal Regions of Mammalian Fibrinogen Aα-Chains

1993 ◽  
Vol 69 (04) ◽  
pp. 351-360 ◽  
Author(s):  
Masahiro Murakawa ◽  
Takashi Okamura ◽  
Takumi Kamura ◽  
Tsunefumi Shibuya ◽  
Mine Harada ◽  
...  
Keyword(s):  
Amino Acid ◽  
Rhesus Monkey ◽  
Syrian Hamster ◽  
Tandem Repeats ◽  
Mammalian Species ◽  
Amino Acid Sequences ◽  
Point Of View ◽  
Cross Linking ◽  
Amino Terminal ◽  
Rgd Sequence

SummaryThe partial amino acid sequences of fibrinogen Aα-chains from five mammalian species have been inferred by means of the polymerase chain reaction (PCR). From the genomic DNA of the rhesus monkey, pig, dog, mouse and Syrian hamster, the DNA fragments coding for α-C domains in the Aα-chains were amplified and sequenced. In all species examined, four cysteine residues were always conserved at the homologous positions. The carboxy- and amino-terminal portions of the α-C domains showed a considerable homology among the species. However, the sizes of the middle portions, which corresponded to the internal repeat structures, showed an apparent variability because of several insertions and/or deletions. In the rhesus monkey, pig, mouse and Syrian hamster, 13 amino acid tandem repeats fundamentally similar to those in humans and the rat were identified. In the dog, however, tandem repeats were found to consist of 18 amino acids, suggesting an independent multiplication of the canine repeats. The sites of the α-chain cross-linking acceptor and α2-plasmin inhibitor cross-linking donor were not always evolutionally conserved. The arginyl-glycyl-aspartic acid (RGD) sequence was not found in the amplified region of either the rhesus monkey or the pig. In the canine α-C domain, two RGD sequences were identified at the homologous positions to both rat and human RGD S. In the Syrian hamster, a single RGD sequence was found at the same position to that of the rat. Triplication of the RGD sequences was seen in the murine fibrinogen α-C domain around the homologous site to the rat RGDS sequence. These findings are of some interest from the point of view of structure-function and evolutionary relationships in the mammalian fibrinogen Aα-chains.

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