scholarly journals Effect of photoinitiator on chain degradation of hyaluronic acid

2019 ◽  
Vol 23 (1) ◽  
Author(s):  
Bo Min Hong ◽  
Su A Park ◽  
Won Ho Park
Keyword(s):  
Hyaluronic Acid ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Proton Nuclear Magnetic Resonance ◽  
Attenuated Total Reflectance ◽  
Oxygen Species ◽  
Photochemical Process ◽  
Phenol Group ◽  
H Nmr

Abstract Objectives Photocrosslinking systems of polymers have been widely studied using UV or visible light irradiation. However, the photodegradation behavior derived from light irradiation was rarely reported, comparing with the photocrosslinking. In this study, the tyramine-modified hyaluronic acid (HA/Tyr) hydrogel was prepared using riboflavin (RF) as a photoinitiator, and the degradation behavior of HA by the reactive oxygen species (ROS) generated in photochemical process was investigated. Materials and methods The HA/Tyr conjugate was synthesized by EDC/NHS chemistry to introduce phenol group. Degree of substitution (DS, %) of phenol group to HA molecule was about 25%. The structural change of HA/Tyr was measured by proton nuclear magnetic resonance (1H-NMR) and attenuated total reflectance infrared spectroscopy (ATR-FTIR), and the rheological properties of photocrosslinked HA/Tyr hydrogel were investigated by rheometer. Results The HA/Tyr solution with 25% substitution formed a stable hydrogel via visible light irradiation in the presence of RF photoinitiator. Rheological data of HA/Tyr solution showed that the storage modulus (G’) was increased with increasing HA concentration. Additionally, it was found that RF initiated by visible light irradiation induced the degradation of HA molecular chain, and consequently reduced the viscosity of HA/Tyr solutions. Conclusion The results indicate that RF-based photoinitiator system caused the degradation of HA molecule by ROS generated in photochemical process as well as the crosslinking of HA/Tyr.

scholarly journals β-Cyclodextrin/Triclosan Complex-Grafted Methacrylated Glycol Chitosan Hydorgel by Photocrosslinking via Visible Light Irradiation for a Tissue Bio-Adhesive

2021 ◽  
Vol 22 (2) ◽  
pp. 700
Author(s):  
Young Jae Moon ◽  
Sun-Jung Yoon ◽  
Jeung-Hyun Koo ◽  
Yihyun Yoon ◽  
Hye Jun Byun ◽  
...  
Keyword(s):  
Wound Healing ◽  
Bacterial Infection ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Tissue Adhesive ◽  
Proton Nuclear Magnetic Resonance ◽  
Scanning Calorimetry ◽  
Glycol Chitosan

Accelerating wound healing with minimized bacterial infection has become a topic of interest in the development of the new generation of tissue bio-adhesives. In this study, we fabricated a hydrogel system (MGC-g-CD-ic-TCS) consisting of triclosan (TCS)-complexed beta-cyclodextrin (β-CD)-conjugated methacrylated glycol chitosan (MGC) as an antibacterial tissue adhesive. Proton nuclear magnetic resonance (1H NMR) and differential scanning calorimetry (DSC) results showed the inclusion complex formation between MGC-g-CD and TCS. The increase of storage modulus (G’) of MGC-g-CD-ic-TCS after visible light irradiation for 200 s indicated its hydrogelation. The swollen hydrogel in aqueous solution resulted in two release behaviors of an initial burst and sustained release. Importantly, in vitro and in vivo results indicated that MGC-g-CD-ic-TCS inhibited bacterial infection and improved wound healing, suggesting its high potential application as an antibacterial tissue bio-adhesive.

Fabrication of magnetic BaFe12O19/Ag3PO4 composites with an in situ photo-Fenton-like reaction for enhancing reactive oxygen species under visible light irradiation

2019 ◽  
Vol 9 (10) ◽  
pp. 2563-2570 ◽  
Author(s):  
Yuanguo Xu ◽  
Feiyue Ge ◽  
Meng Xie ◽  
Shuquan Huang ◽  
Junchao Qian ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Reactive Oxygen ◽  
Light Irradiation ◽  
Oh Radicals ◽  
Oxygen Species

An in situ photo-Fenton-like and magnetic recycle system, BaFe12O19/Ag3PO4 has been constructed. BaFe12O19 can catalyze the conversion of H2O2 to generate ROSs (˙O2− and ˙OH radicals) on the surface of Ag3PO4.

scholarly journals Degradation of Penicillin G by Visible Light Irradiation-Assisted Biotransformation by Whole Cell paracoccus sp .

2020 ◽  
Author(s):  
Peng Wang ◽  
Chen Shen ◽  
Qinqin Cong ◽  
Jialin Lu ◽  
Xiaochun Wang
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Genomic Analysis ◽  
Light Irradiation ◽  
Penicillin G ◽  
Key Factors ◽  
Whole Cell ◽  
H Nmr ◽  
Kinetics Of ◽  
Catalytic Effects

Abstract Background: The Paracoccus sp. strain (KDSPL-02) isolated from sludge was identified and evaluated for catalytic activity in the degradation of penicillin G. Results: High degradation efficiency and synergistic catalytic effects of the whole cell and visible light without additional catalysts were observed. The key factors influencing the degradation and kinetics of penicillin G were investigated. The results showed the phenylacetic acid, which was produced during penicillin G biodegradation, exhibited stronger inhibiting effects on KDSPL-02. However, this effect was reduced by visible light irradiation without any additional photocatalyst; furthermore, the rate of penicillin G biodegradation was accelerated, reaching a 100% rate in 12 h at a penicillin G concentration of 1.2 g/L. Four key intermediates produced during penicillin G degradation were isolated and identified by LC–MS, 1H NMR, and 13C NMR. Enzymes involved in the PAA pathway were proposed from a genomic analysis of paracoccus sp. KDSPL-02. Conclusions:These results provide a new method for bio-degrading of penicillin or other antibiotic pollutants using photoaccelerating biocatalysts with greater efficiency and more environmentally friendly conditions.

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