Synthesis, characterization, and enzymatic degradation of chitosan/PEG hydrogel films

2011 ◽  
Vol 122 (3) ◽  
pp. 1556-1563 ◽  
Author(s):  
Aylin Altinisik ◽  
Kadir Yurdakoc
Keyword(s):  
Enzymatic Degradation ◽  
Hydrogel Films

Characterization and enzymatic degradation of PEG-cross-linked chitosan hydrogel films

2009 ◽  
Vol 114 (3) ◽  
pp. 1902-1907 ◽  
Author(s):  
Hiroaki Tanuma ◽  
Hiroki Kiuchi ◽  
Weihua Kai ◽  
Koji Yazawa ◽  
Yoshio Inoue
Keyword(s):  
Enzymatic Degradation ◽  
Chitosan Hydrogel ◽  
Hydrogel Films

Preparation and characterization of PEG-cross-linked chitosan hydrogel films with controllable swelling and enzymatic degradation behavior

2010 ◽  
Vol 80 (1) ◽  
pp. 260-265 ◽  
Author(s):  
Hiroaki Tanuma ◽  
Takashi Saito ◽  
Kenichi Nishikawa ◽  
Tungalag Dong ◽  
Koji Yazawa ◽  
...  
Keyword(s):  
Enzymatic Degradation ◽  
Degradation Behavior ◽  
Chitosan Hydrogel ◽  
Hydrogel Films

Role of the exosporial membrane in attachment and germination of C. sporogenes

1993 ◽  
Vol 51 ◽  
pp. 38-39
Author(s):  
B.J. Panessa-Warren ◽  
G.T. Tortora ◽  
J.B. Warren
Keyword(s):  
Enzymatic Degradation ◽  
Light Transmission ◽  
Extended Period ◽  
Growth Conditions ◽  
Clostridium Sporogenes ◽  
Radiation Chemical ◽  
Physical Trauma ◽  
Extended Contact ◽  
Cold Pressure

Some bacteria are capable of forming highly resistant spores when environmental conditions are not adequate for growth. Depending on the genus and species of the bacterium, these endospores are resistant in varying degrees to heat, cold, pressure, enzymatic degradation, ionizing radiation, chemical sterilants,physical trauma and organic solvents. The genus Clostridium, responsible for botulism poisoning, tetanus, gas gangrene and diarrhea in man, produces endospores which are highly resistant. Although some sporocides can kill Clostridial spores, the spores require extended contact with a sporocidal agent to achieve spore death. In most clinical situations, this extended period of treatment is not possible nor practical. This investigation examines Clostridium sporogenes endospores by light, transmission and scanning electron microscopy under various dormant and growth conditions, cataloging each stage in the germination and outgrowth process, and analyzing the role played by the exosporial membrane in the attachment and germination of the spore.

Increased cysteine-protease activity in fecal supernatants from constipated IBS-C patients leads to occludin enzymatic degradation in colonic mucosa

2011 ◽  
Vol 49 (05) ◽  
Author(s):  
R Róka ◽  
A Annaházi ◽  
V Bezirard ◽  
H Eutamene ◽  
L Ferrier ◽  
...  
Keyword(s):  
Cysteine Protease ◽  
Protease Activity ◽  
Enzymatic Degradation ◽  
Colonic Mucosa ◽  
Cysteine Protease Activity

Efficiency of Tranexamic Acid in Management of Surgical Orthopedic Bleeding in Patients with Haemophilia

2017 ◽  
Vol 68 (3) ◽  
pp. 627-630 ◽  
Author(s):  
Oana Viola Badulescu ◽  
Razvan Tudor ◽  
Wilhelm Friedl ◽  
Mihaela Blaj ◽  
Paul Dan Sirbu
Keyword(s):  
Tranexamic Acid ◽  
Orthopaedic Surgery ◽  
Enzymatic Degradation ◽  
Point Of View ◽  
Factor Ix ◽  
Haemophilia A ◽  
Chromosome X ◽  
Risk Of Bleeding ◽  
Subchondral Bone Tissue ◽  
Knee Endoprosthesis

Haemophilia is an inherited bleeding disorder (gonosomala recessive, related to chromosome X, with transmission from carrying women to male descendents) characterised from the clinic point of view by important bleeding, secondary to some minimum and biologic traumas by deficiency of trombo-plastino-formation, consecutive to either a deficit of factor VIII (haemophilia A), or the factor IX (haemophilia B). The most characteristic manifestation of hemophilia is intra-articular � hemarthrosis. Its repetitive character leads to irreversible lesions of the articular structures, inducing lesions of the synovium with degenerative effects over the articular cartilage and destructive effects for the subchondral bone tissue. In time, these lesions require orthopaedic surgery to improve the locomotor activity. Managing an efficient hemostasis is vital during surgery, due to high risk of bleeding triggered by coagulopathy and surgery. Numerous studies carried out underlined the efficiency of the tranexamic acid (TXA) in reducing bleeding, in different surgery branches, by inhibiting the enzymatic degradation of fibrin. In orthopaedic surgery, the tranexamic acid is frequently used in case of hip and knee arthroplasties, reducing the bleeding and blood transfusion necessary to the treatment of posthaemorrhagic anemia. This paper wants to assess the efficiency of the tranexamic acid in realization of hemostasis to another category of patients, haemophiliac patients with indication of total hip and knee endoprosthesis.

Design and Delivery of Therapeutic siRNAs: Application to MERS-Coronavirus

2018 ◽  
Vol 24 (1) ◽  
pp. 62-77 ◽  
Author(s):  
Sayed Sartaj Sohrab ◽  
Sherif Aly El-Kafrawy ◽  
Zeenat Mirza ◽  
Mohammad Amjad Kamal ◽  
Esam Ibraheem Azhar
Keyword(s):  
Enzymatic Degradation ◽  
Polymeric Nanoparticles ◽  
Genetic Disorders ◽  
Inorganic Nanoparticles ◽  
Innovative Technology ◽  
Viral Diseases ◽  
Viral Gene ◽  
Efficient Delivery ◽  
Disease Therapy ◽  
Target Sites

Background: The MERS-CoV is a novel human coronavirus causing respiratory syndrome since April 2012. The replication of MERS-CoV is mediated by ORF 1ab and viral gene activity can be modulated by RNAi approach. The inhibition of virus replication has been documented in cell culture against multiple viruses by RNAi approach. Currently, very few siRNA against MERS-CoV have been computationally designed and published. Methods: In this review, we have discussed the computational designing and delivery of potential siRNAs. Potential siRNA can be designed to silence a desired gene by considering many factors like target site, specificity, length and nucleotide content of siRNA, removal of potential off-target sites, toxicity and immunogenic responses. The efficient delivery of siRNAs into targeted cells faces many challenges like enzymatic degradation and quick clearance through renal system. The siRNA can be delivered using transfection, electroporation and viral gene transfer. Currently, siRNAs delivery has been improved by using advanced nanotechnology like lipid nanoparticles, inorganic nanoparticles and polymeric nanoparticles. Conclusion: The efficacy of siRNA-based therapeutics has been used not only against many viral diseases but also against non-viral diseases, cancer, dominant genetic disorders, and autoimmune disease. This innovative technology has attracted researchers, academia and pharmaceuticals industries towards designing and development of highly effective and targeted disease therapy. By using this technology, effective and potential siRNAs can be designed, delivered and their efficacy with toxic effects and immunogenic responses can be tested against MERS-CoV.

Phase-separation enhanced enzymatic degradation of atactic poly(R,S-3-hydroxybutyrate) in the blends with poly(methyl methacrylate)

2003 ◽  
Vol 79 (3) ◽  
pp. 535-545 ◽  
Author(s):  
Yang-Ho Na ◽  
Yong He ◽  
Tetsuo Nishiwaki ◽  
Yasuhide Inagawa ◽  
Yasushi Osanai ◽  
...  
Keyword(s):  
Phase Separation ◽  
Methyl Methacrylate ◽  
Enzymatic Degradation ◽  
Poly Methyl Methacrylate

scholarly journals On the Effectiveness of Oxygen Plasma and Alkali Surface Treatments to Modify the Properties of Polylactic Acid Scaffolds

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1643
Author(s):  
Ricardo Donate ◽  
María Elena Alemán-Domínguez ◽  
Mario Monzón
Keyword(s):  
Surface Properties ◽  
Enzymatic Degradation ◽  
Oxygen Plasma ◽  
Physicochemical Characterization ◽  
Surface Treatments ◽  
Carboxyl Groups ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Angle Measurements ◽  
3D Printed

Surface modification of 3D-printed PLA structures is a major issue in terms of increasing the biofunctionality and expanding the tissue engineering applications of these parts. In this paper, different exposure times were used for low-pressure oxygen plasma applied to PLA 3D-printed scaffolds. Alkali surface treatments were also evaluated, aiming to compare the modifications introduced on the surface properties by each strategy. Surface-treated samples were characterized through the quantification of carboxyl groups, energy-dispersive X-ray spectroscopy, water contact angle measurements, and differential scanning calorimetry analysis. The change in the surface properties was studied over a two-week period. In addition, an enzymatic degradation analysis was carried out to evaluate the effect of the surface treatments on the degradation profile of the 3D structures. The physicochemical characterization results suggest different mechanism pathways for each type of treatment. Alkali-treated scaffolds showed a higher concentration of carboxyl groups on their surface, which enhanced the enzymatic degradation rate, but were also proven to be more aggressive towards 3D-printed structures. In contrast, the application of the plasma treatments led to an increased hydrophilicity of the PLA surface without affecting the bulk properties. However, the changes on the properties were less steady over time.

scholarly journals The Influence of Bloom Index, Endotoxin Levels and Polyethylene Glycol Succinimidyl Glutarate Crosslinking on the Physicochemical and Biological Properties of Gelatin Biomaterials

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1003
Author(s):  
Zhuning Wu ◽  
Stefanie H. Korntner ◽  
Jos Olijve ◽  
Anne Maria Mullen ◽  
Dimitios I. Zeugolis
Keyword(s):  
Elastic Modulus ◽  
Polyethylene Glycol ◽  
Enzymatic Degradation ◽  
Structural Integrity ◽  
Biological Response ◽  
Biological Properties ◽  
Compression Stress ◽  
Free Amine ◽  
Amine Content ◽  
Physicochemical And Biological Properties

In the medical device sector, bloom index and residual endotoxins should be controlled, as they are crucial regulators of the device’s physicochemical and biological properties. It is also imperative to identify a suitable crosslinking method to increase mechanical integrity, without jeopardising cellular functions of gelatin-based devices. Herein, gelatin preparations with variable bloom index and endotoxin levels were used to fabricate non-crosslinked and polyethylene glycol succinimidyl glutarate crosslinked gelatin scaffolds, the physicochemical and biological properties of which were subsequently assessed. Gelatin preparations with low bloom index resulted in hydrogels with significantly (p < 0.05) lower compression stress, elastic modulus and resistance to enzymatic degradation, and significantly higher (p < 0.05) free amine content than gelatin preparations with high bloom index. Gelatin preparations with high endotoxin levels resulted in films that induced significantly (p < 0.05) higher macrophage clusters than gelatin preparations with low endotoxin level. Our data suggest that the bloom index modulates the physicochemical properties, and the endotoxin content regulates the biological response of gelatin biomaterials. Although polyethylene glycol succinimidyl glutarate crosslinking significantly (p < 0.05) increased compression stress, elastic modulus and resistance to enzymatic degradation, and significantly (p < 0.05) decreased free amine content, at the concentration used, it did not provide sufficient structural integrity to support cell culture. Therefore, the quest for the optimal gelatin crosslinker continues.

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