دانلود رایگان مقاله camphorquinone کربوکسیله به عنوان آغازگر نوری نور مرئی برای استفاده پزشکی

Abstract

Camphorquinone (CQ) is by far the most widely used visible-light photoinitiator in biomedical applications. Despite the fact that CQ is well established and has a good clinical acceptance, photoinitiating systems based on CQ have some drawbacks in particular poor water solubility and low photoreactivity. Here the synthesis and testing of a new camphorquinone derivative are described. Carboxylated-camphorquinone (CQCOOH) was synthesized using ketopinic acid as the starting material. The chemical structure of CQCOOH was verified by 1 H-NMR, 1 H–13C-COSY-NMR, FT-IR, mass spectroscopy, and UV–visible spectrophotometry. CQCOOH was used with an amine coinitiator and diphenyliodonium chloride (DPIC) accelerator as a visible light induced photoinitiating system for the preparation of hydrogels. CQCOOH exhibits a significantly higher photoreactivity compared to CQ with the same amine-DPIC system. Already after 5 s exposure time, the polymer crosslinked with the CQCOOH-amine-DPIC system to form a hydrogel. Furthermore, higher crosslink density and better mechanical properties are observed compared to those hydrogels prepared with the CQ-amine-DPIC system. Experiments measuring the activity or integrity of cells (MTT and LDH assay, respectively) were performed to investigate the compatibility of the photoinitiating system components with human gingival fibroblast (HGF). According to hese experiments neither CQCOOH, L-arginine nor N-phenylglycine as amine coinitiators have toxic effects even in high concentrations. In contrast, HGF cell viability is considerably decreased at DPIC-concentrations higher than 0.25%.

5. Conclusion

In summary, we have described the synthesis and characterization of carboxylated camphorquinone (CQCOOH) as a watersoluble photoinitiating system to be used with visible light. It was shown that CQCOOH with an amine coinitiator and an accelerator gives a very reactive photoinitiator system, which in aqueous solution is more effective than a system based on the commercial and conventional camphorquinone (CQ). The high photoreactivity of carboxylated camphorquinone has been proven by a quick formation of crosslinked polymer, higher crosslink density, higher degree of double bond conversion (DC%), and better mechanical properties (high storage modulus) compared to hydrogels crosslinked with the camphorquinone system. The high photoreactivity of CQCOOH-amine-DPIC system can be ascribed to the presence of the additional camphor group like the COOH-group which improved the solubility and with that the homogeneity and light sensitivity of the system. Carboxylated camphorquinone is highly biocompatible, no toxic effects were found by MTT and LDH assays with HGF cells. While, NPG and L-arginine as amine coinitiators are also non-toxic, the accelerator DPIC reduced cell viability apparently. Carboxylated camphorquinone as a visible-light photoinitiator has great potential to replace the conventional used camphorquinone in aqueous systems for various biomedical applications.