Mussel-inspired in situ forming adhesive hydrogels with anti-microbial and hemostatic capacities for wound healing

2018 ◽  
Vol 33 (7) ◽  
pp. 915-923 ◽  
Author(s):  
Xiaoman Han ◽  
Guihua Meng ◽  
Qian Wang ◽  
Lin Cui ◽  
Hao Wang ◽  
...  
Keyword(s):  
Glutamic Acid ◽  
Phosphate Buffer Solution ◽  
Wound Dressings ◽  
Buffer Solution ◽  
Adhesion Properties ◽  
H Nmr ◽  
Chemical Structures ◽  
In Situ Forming ◽  
Ft Ir

All kinds of commercially available wound dressings are clinically used as fleshly obstacles and therapeutic materials in opposition to microbial incursion. Few researches focused on effective-bleeding and anti-bacteria at the same time. In order to better solve this problem, two hydrogels were synthetized in this study. One is phosphate buffer solution-activated dopamine-modified-γ-poly glutamic acid (PBS-PD) hydrogel, the other one is cirsium setosum extracts-activated dopamine-modified-γ-poly glutamic acid (CSE-PD) hydrogel. The two hydrogels are prepared by applying an enzyme-catalyzed crosslinking means in the presence of horseradish peroxidase (HRP) and hydrogen peroxide (H2O2). The chemical structures were characterized through 1H-NMR and FT-IR. In conclusion, both PBS-PD and CSE-PD hydrogels exhibit superior tissue adhesion properties, and remarkable anti-infection quality. In addition, these two hydrogels manifest prominent hemostatic efficiency. The bio adhesion performance can achieve 30 kPa, meanwhile the CSE-PD hydrogels show good germicidal properties, and the antibacterial rate can reach 98%. The hydrogels could reduce blood loss without any obvious side effect, and present a new prospect in the field of hemostasis rapidly.

Synthesis, characterization, and drug delivery property of 2-N-carboxymethyl-6-O-diethylaminoethyl-chitosan

e-Polymers ◽  
2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Aidi Zhang ◽  
Derun Ding ◽  
Jicun Ren ◽  
Xiangli Zhu ◽  
Youhong Yao
Keyword(s):  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Controlled Delivery ◽  
Protective Agent ◽  
Buffer Solution ◽  
Solution Ph ◽  
H Nmr ◽  
Structure Morphology ◽  
Ft Ir ◽  
Model Drug

Abstract A novel route is demonstrated for the synthesis of 2-N-carboxymethyl-6- O-diethylaminoethyl-chitosan (DEAE-CMC) by incorporation of carboxymethyl groups as hydrophilic moieties to the C2-NH2, and diethylaminoethyl groups as hydrophobic moieties to the C6-CH2OH of the structural unit of chitosan, via a protection-graft-deprotection procedure with benzaldehyde as protective agent. The structure, morphology, and thermal properties of the chitosan graft copolymers were characterized by means of FT-IR, 1H NMR, SEM, TGA and DSC. Chitosan and its derivatives were used as carrier of model drug-Vitamin B12 (VB12), and their controlled delivery behaviour in phosphate buffer solution (pH 7.4) were studied. The results show that the release rate of VB12 from the carrier of DEAE-CMC copolymer becomes much slower than that of chitosan in phosphate buffer solution.

scholarly journals Crosslinking Efficacy and Cytotoxicity of Genipin and Its Activated Form Prepared by Warming It in a Phosphate Buffer: A Comparative Study

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6600
Author(s):  
Takeya Kawamura ◽  
Shunji Yunoki ◽  
Yoshimi Ohyabu ◽  
Toshio Uraoka ◽  
Kazuaki Muramatsu
Keyword(s):  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Mechanical Tests ◽  
Buffer Solution ◽  
Sodium Phosphate Buffer ◽  
In Situ Forming ◽  
Custom Made ◽  
Acute Cytotoxicity ◽  
Sodium Phosphate Buffer Solution

The aim of the present study was to compare the acute and cumulative cytotoxicity of intact (n-GE) and warmed genipin (w-GE), while investigating the differences in crosslinking capabilities of these two genipins by rheological and mechanical tests. The n-GE solution was prepared by dissolving genipin powder in a sodium phosphate buffer solution. The w-GE solution was prepared by warming the n-GE solution at 37 °C for 24 h. The mechanical tests for chitosan (CH)/genipin gels showed the crosslinking rate of w-GE was much greater than that of n-GE up until 6 h after preparation, whereas the degree of crosslinking of CH/n-GE gels became higher at 12 h. The ISO 10993-5 standard method, which is established specifically for evaluating cumulative cytotoxicity, determined equivalent IC50 for w-GE (0.173 mM) and n-GE (0.166 mM). On the other hand, custom-made cytotoxicity tests using a WST-8 assay after 1 h of cultivation showed that the acute cytotoxicity of w-GE was significantly higher than that of n-GE at concentrations between 0.1–5 mM. The acute cytotoxicity of w-GE should be taken into consideration in its practical uses, despite the fact that the much faster crosslinking of w-GE is useful as an effective cross linker for in-situ forming gels.

scholarly journals Synthesis, Characterization, and Antimicrobial Activity of Methyl-2-aminopyridine-4-carboxylate Derivatives

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
S. Nagashree ◽  
P. Mallu ◽  
L. Mallesha ◽  
S. Bindya
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Studies ◽  
H Nmr ◽  
Chemical Structures ◽  
Elemental Analyses ◽  
Ft Ir

A series of methyl-2-aminopyridine-4-carboxylate derivatives,3a–f,were synthesized in order to determine theirin vitroantimicrobial activity. The chemical structures of the synthesized compounds were confirmed by elemental analyses, FT-IR, and1H NMR spectral studies. Among the synthesized compounds,3cand3dshowed good antimicrobial activity compared to other compounds in the series.

scholarly journals Synthesis of a water-soluble 2,2′-biphen[4]arene and its efficient complexation and sensitive fluorescence enhancement towards palmatine and berberine

2018 ◽  
Vol 14 ◽  
pp. 2236-2241 ◽  
Author(s):  
Xiayang Huang ◽  
Xinghua Zhang ◽  
Tianxin Qian ◽  
Junwei Ma ◽  
Lei Cui ◽  
...  
Keyword(s):  
Association Constant ◽  
Fluorescence Enhancement ◽  
Phosphate Buffer Solution ◽  
Water Soluble ◽  
Binding Affinities ◽  
Buffer Solution ◽  
Solution Ph ◽  
H Nmr ◽  
Naked Eye ◽  
Nmr Signals

A water-soluble 2,2′-biphen[4]arene (2,2’-CBP4) containing eight carboxylato moieties was synthesized and characterized. Its complexation behavior towards two alkaloids, palmatine (P) and berberine (B), was investigated by means of fluorescence and 1H NMR spectroscopy in aqueous phosphate buffer solution (pH 7.4). In the presence of 2,2’-CBP4, 1H NMR signals of P and B displayed very large upfield shifts, indicating the formation of inclusion complexes with strong binding affinities. Fluorescence titration experiments showed that P and B exhibited dramatic fluorescence enhancement of more than 600 times upon complexation with 2,2’-CBP4. Particularly, the fluorescence intensity is strong enough to be readily distinguished by the naked eye. Although the two guests have similar structures, the association constant of B with 2,2’-CBP4 (K a = (2.29 ± 0.27) × 106 M−1) is 3.9 times larger than that of P (K a = (5.87 ± 0.24) × 105 M−1).

scholarly journals Synthesis of New Imidazolidine and Tetrahydropyrimidine Derivatives

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Hamid Beyzaei ◽  
Reza Aryan ◽  
Zahra Keshtegar
Keyword(s):  
Ring Opening ◽  
Reaction Times ◽  
Reaction Conditions ◽  
Ir Spectrometry ◽  
H Nmr ◽  
Chemical Structures ◽  
Thioamide Group ◽  
Solvent Free Conditions ◽  
Ft Ir ◽  
C Nmr

Synthesis of new imidazolidine and tetrahydropyrimidine derivatives 3a, b and 4a–c as cyclic 1,3-diamines under two reaction conditions (A and B) is described. Under reaction conditions-A, a suspension of (E)-2-cyano-2-(oxazolidin-2-ylidene)ethanethioamide 1 (1 eq.) and diaminoalkanes 2a–e (2 eq.) in absolute ethanol is heated under reflux for 16–22 h to afford 3a, b and 4a–c. Alternatively, under reaction conditions-B, a solution of thioamide 1 (1 eq.) in diaminoalkanes 2a–e (3 eq.) is stirred under solvent-free conditions at room temperature for 3 days to give desired products. Reaction conditions-A for having higher yields, shorter reaction times, and required less diamines is more effective than reaction conditions-B. Oxazolidine ring opening is observed by reacting compound 1 with all of the diamines 2a–e, but the thioamide group only reacts with nonbulky diamines 2a, b. The chemical structures of novel compounds were confirmed by 1H NMR, 13C NMR, elemental analysis, and FT-IR spectrometry.

Synthesis of Bis(2, 4-Dihydro-2H-3-(4-N-Maleimido) Phenyl -1, 3-Benzoxazine)Isopropane

2011 ◽  
Vol 287-290 ◽  
pp. 688-693
Author(s):  
Guo Tao ◽  
You Hui Xu ◽  
Gang Yang
Keyword(s):  
Maleic Anhydride ◽  
Target Object ◽  
The Novel ◽  
H Nmr ◽  
Chemical Structures ◽  
Ft Ir

The novel bis(2, 4-dihydro-2H-3-(4-N-maleimido) phenyl-1, 3-benzoxazine)isopropane (BMIPBI) was synthesized from maleic anhydride, p-nitroaniline, formaldehyde and 2,2-bis(4-hydr -oxyphenyl)propane by a few steps reactions via the N-(4-nitrophenyl)maleimide(NPMI), N-(4-amin -ophenyl)maleimide(APMI),1,3,5-three(4-(maleimido)phenyl)-1,3,5-triazine(TMIPT)intermediate production. The chemical structures of BMIPBI were confirmed by 1H-NMR, FT-IR and EA. The results show that the production was the target object BMIPBI. The synthesized condition had been studied too. The BMIPBI was a loosened yellow solid and the yield of product was 58.8%.

scholarly journals Chemical modification of TiO2 by H2PO4−/HPO42− anions using the sol-gel route with controlled precipitation and hydrolysis: enhancing thermal stability

2014 ◽  
Vol 32 (4) ◽  
pp. 617-625 ◽  
Author(s):  
Kais Elghniji ◽  
Mohamed Saad ◽  
Manel Araissi ◽  
Elimame Elaloui ◽  
Younes Moussaoui
Keyword(s):  
31P Nmr ◽  
Sol Gel ◽  
Phosphate Buffer Solution ◽  
Rutile Phase ◽  
Titanium Phosphate ◽  
Buffer Solution ◽  
Raman Analysis ◽  
Phosphate Species ◽  
Ft Ir ◽  
Controlled Precipitation

AbstractTwo titanium phosphate materials (TpP and ThP) have been successfully synthesized by sol-gel route with controlled precipitation and hydrolysis. The TpP material was obtained from the reaction between precipitated titania and phosphate buffer solution H2PO4− /HPO42− (pH = 7.3). The TpP material was prepared through hydrolysis of titanium in the presence of H2PO4−/HPO42. The probable state of the phosphate anions in titania framework and their effect on the anatase-to-rutile transformation were characterized by ICP-AES, DTA-TG, 31P NMR, FT-IR, and Raman analysis HRTEM/SEM. FT-IR and 31P NMR analyses of titanium phosphate TpP calcined at low temperature showed that the phosphate species existed not only as Ti-O-P in the bulk TiO2 but also as amorphous titanium phosphates, including bidentate Ti(HPO4)2 and monodentate Ti(H2PO4)4. Increased calcination temperature only gave an enrichment of bidentate structure on the titania surface. For the TpP material, H2PO4−/HPO42− anions were introduced into the initial solution, before precipitation, what promoted their lattice localization. At high temperatures, all the phosphorus inside the bulk of TiO2 migrated to the surface. The Raman analysis of both samples showed that the bidentate phosphates increased the temperature of the anatase-to-rutile phase transformation to more than 1000 °C with the formation of well crystalline TiP2O7 phase. This phenomenon was more evident for TpP sample.

scholarly journals Erratum: Investigation of drug release and 1 H-NMR analysis of the in situ forming systems based on poly(lactide-co-glycolide)

2009 ◽  
Vol 20 (5) ◽  
pp. 507-507
Author(s):  
Z. Mohamadnia ◽  
E. Ahmadi ◽  
M. Rafienia ◽  
H. Mirzadeh ◽  
H. Mobedi
Keyword(s):  
Drug Release ◽  
Nmr Analysis ◽  
H Nmr ◽  
In Situ Forming

scholarly journals Vancomycin-releasing cross-linked collagen sponges as wound dressings

2019 ◽  
Author(s):  
Jan Miroslav Hartinger ◽  
Peter Lukáč ◽  
Petr Mitáš ◽  
Mikuláš Mlček ◽  
Michaela Popková ◽  
...  
Keyword(s):  
Phosphate Buffer Solution ◽  
Collagen Type I ◽  
Wound Dressings ◽  
Homogeneous Distribution ◽  
Infrared Spectrometry ◽  
Type I ◽  
Micro Computed Tomography ◽  
Buffer Solution ◽  
Microbiological Testing

The study presents a novel vancomycin-releasing collagen wound dressing derived from Cyprinus carpio collagen type I cross-linked with carbodiimide which retarded the degradation rate and increased the stability of the sponge. Following lyophilization, the dressings were subjected to gamma sterilization. The structure was evaluated via scanning electron microscopy images, micro-computed tomography, and infrared spectrometry. The structural stability and vancomycin release properties were evaluated in a phosphate buffer solution. Microbiological testing and a rat model of a wound infected with methicillin-resistant Staphylococcus aureus (MRSA) were then employed to test the efficacy of the treatment of the infected wound. Following an initial mass loss due to the release of vancomycin, the sponges remained stable. After 7 days of exposure in phosphate buffered saline (37°C), 60% of the material remained with a preserved collagen secondary structure together with a high degree of open porosity (over 80%). The analysis of the release of the vancomycin revealed the homogeneous distribution of the antibiotic both across and between the sponges. The release of vancomycin was retarded as proved by in vitro testing and further confirmed by the animal model from which measurable concentrations were observed in blood samples 24 hours after the subcutaneous implantation of the sponge, which was more than observed following i. p. administration. The sponge was also highly effective in terms of reducing the number of colony-forming units in biopsies extracted from the infected wounds 4 days following the inoculation of the wounds with the MRSA solution.

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