Investigation of photoinduced polymerization of doxycycline-imprinted hydrogels: effect of template on initiator reactivity, conversion, and reaction rate

Abstract

Photopolymerization kinetics of doxycycline hyclate (DOX)-imprinted hydrogels were monitored by real-time Fourier transform infrared spectroscopy and differential photocalorimetry. 2-Hydroxyethyl methacrylate-based hydrogels were synthesized by using ethylene glycol dimethacrylate as a cross-linker, acrylic acid (AA) as a functional monomer, and 2,2-dimethyl-2-hydroxy acetophenone as a photoinitiator. For imprinting DOX in hydrogels, the molar ratio of template to functional monomer (DOX:AA) was chosen as 1:8 and 1:16. The polymerization was achieved at two different initiator concentrations. The conversion and reaction rate were calculated as a function of the molar ratio of template, and the results were compared to those of nonimprinted ones. In order to reveal the effect of DOX on the photoinduced radical polymerization, thermal polymerization was also performed for imprinted and nonimprinted hydrogels by using 2,2 ′ -azobis(2,4-dimethyl-pentanenitrile) as a thermal initiator. All results showed that there is a significant effect of DOX concentration on the conversion and reaction rate of the photopolymerization reaction. The conversion and reaction rate decreased during photopolymerization when the template concentration increased in the monomer mixture.

Preparation and Determination of In Vivo and In Vitro Performance of Doxycycline Imprinted Contact Lenses for Corneal Neovascularization Treatment

“…Molecular imprinted contact lenses were synthesized via free radical polymerization (14). Doxycycline (0.205% mole) was dissolved in HEMA (92% mole) during 30 min in ultrasonic bath below 40 °C.…”

“…We chose thermal polymerization, since doxycycline molecule is sensitive to UV light (14). Teflon mold built for rat's eyes was used in contact lens synthesis, and the contact lenses were prepared in two different diameters ( Figure 2).…”

“…Recently, a series of doxycycline imprinted hydrogels have been prepared from acrylic acid as a functional monomer and ethylene glycol dimethylacrylate as a cross-linker (14). We investigated the reaction kinetics for photo-and thermal polymerization via real-time FTIR spectroscopy and differential photocalorimetry.…”

“…In this study, hydrogel contact lenses were synthesized using molecular imprinting method as in our previous study (14). The active ingredient of the drug chosen for the treatment is doxycycline.…”

Elucidating doxycycline loading and release performance of imprinted hydrogels with different cross-linker concentrations: a computational and experimental study

“…At this point, molecularly imprinted contact lenses appear as an ideal solution to treat the disease with the correct dosage. For this purpose, hydrogels with imprinted DOX were developed by our group for the first time [54], and we tested these as therapeutic contact lenses in vivo [55]. First, the effects of initiator reactivity, conversion, and reaction rate on photopolymerization kinetics of DOX imprinted on AA-based hydrogels were elaborated by our group [54].…”