Preparation And Characterization Of NVCL Temperature And Glucose Sensitive Microgel

Stimuli responsive polymer as its name implies is a kind of polymer that can respond to the external stimulating factors by swelling or shrinking of volume, these factors include temperature, pH, light, electricity, magnetism and others. Because of this performance they have great application potential in tissue engineering, biosensors, cell culture, drug delivery and many other biomedical fields. These intelligent materials have been widely concerned and researched.Temperature-sensitive polymer is a class of smart polymer that can change with the change of the external environmental temperature, Among them, with a lower critical solution temperature (LCST) polymers have already became the focus under study.These polymers usually contain amide bonds, ether bond, hydroxyl and other funcational groups, the most typical temperature-sensitive polymers are N-Vinylcaprolactam based polymer (PVCL) and N-isopropylacrylamide based polymer (PNIPAM) because their LCST have been kept in the range of physiological temperature (30-40℃).Glucose-sensitive polymer plays a key role in the design of self-regulated insulin release systems, phenylboronic acid as a glucose-sensitive monomer has been attracting the attention of quite a few reaserchers because of its low toxicity, high stability. The classification, characteristics and the current situation of these sensitive polymer were reviewed herein.PVCL microgel was synthesized by soap-free emulsion polymerization, with N-Vinylcaprolactam (NVCL) used as the thermosensitive monomer,2,2’-Azodiisobutyramidine Dihydrochloride(AIBA) as the initiator N,N’-Methylenebisacrylamide (MBA) as the cross-links, water as the medium. A series of microgels were synthesized by changing the dosage of initiator and cross-links. The microgels were characterized via Fourier transfer infrared spectroscopy(FTIR), Energy Dispersive X-Ray Spectroscopy (EDX), transmission electron microscopy (TEM) and dynamic laser light scattering (DLS). The results of FTIR and EDX indicate that the successful synthesis of the target product, TEM and SEM show the spherical monodisperse morphology, and different dosage of initiator and cross-links on the microgels cannot impact on the LCST of the microgels but on the size and swelling force of the particles, moreover, we found that when the dosage of cross-links is5%, the dosage of inititor is1.5%, the microgel has good comprehensive performance.PVCL-PBA microgel was synthesized by soap-free emulsion polymerization, with N-Vinylcaprolactam (NVCL) used as the thermosensitive monomer,4-vinylphenylboronic acid (PBA) as the glucose-sensitive monomer,2,2’-Azodiisobutyramidine Dihydrochloride (AIBA) as the initiator, N,N’-Methylenebisacrylamide (MBA) as the cross-links, water as the medium, with the optimal selecred dosage of cross-links and inititor in last part, a series of PVCL-PBA microgels were synthesized by changing the molar ratio of NVCL to PBA. The microgels were characterized via Fourier transfer infrared spectroscopy (FTIR), Energy Dispersive X-Ray Spectroscopy (EDX), Transmission electron microscopy (TEM), Dynamic laser light scattering (DLS), UV visible spectrophotometer (UV-VIS), enzyme-labeled instrument. The results of FTIR and EDX indicate that the successful synthesis of the target product, the result of SEM and TEM shows when the molar ratio of PBA representing monomer12.5%, the particles is monodisperse preferably, choose it as the best sample, which can be used to do subsequent test, the result of UV spectrophotometer show microgel have good drug sustained-release ability, microgel have low toxicity, good biocompatibility measured by MTT assay.All of this demonstrated that the copolymer have a wide foreground in the future.