Study On Preparation And Properties Of The Hydrogels Based On Arginine And Its Application In Dressing

Zwitterionic hydrogels possessed the function of anti-fouling and anti-protein adsorption due to its strong hydrophilic.The zwitterionic modified ariginine（M-Arg）monomer was prepared with ariginine in this paper,and then the PNIPAAm,P（M-Arg/NIPAAm）and P（M-Arg）hydrogels were carried out by free radical copolymerization of M-Arg and N-isopropyl acrylamide（NIPAAm）monomers using N,N-methylene bisacrylamide（BIS）as cross-linker,and APS/TEMED as the redox initiator.To improve the antibacterial property of the hydrogels,the spectrum antimicrobial agents of chlorhexidine（CHX）and the prepared oligoguanidine（PHMG）were introduced into hydrogels by means of preloading and grafting,respectively.The structure and morphology of M-Arg,PHMG and hydrogels was chacracterized by 1H NMR,FT-IR and SEM;the swelling properties,mechanical and antibacterial properties of hydrogels were investigated by swelling ratio assessment,compression modulus experiment,cumulative release of drug and antibacterial assessment;the protein adsorption and cells experiment were used to discuss the anti-fouling and anti-protein adsorption of hydrogels;the biocompatibility of hydrogels was assessed by cell cytotoxicity and animal test in vivo.1.Equilibrium swelling ratio suggested that the lower critical solution temperature of PNIPAAm was about 32 oC and P（M-Arg/NIPAAm）₁ hydrogels was certain sensitive to temperature but P（M-Arg）hydrogel was not sensitive to temperature after the swelling ratio test of PNIPAAm,P（M-Arg/NIPAAm）and P（M-Arg）hydrogels from 20 oC to 60 oC.And the equilibrium swelling ratio of hydrogels decreased with an increasing in the crosslinking bonds per unit volume.2.Mechanical test sugguested that PNIPAAm hydrogel displayed the highest mechanical strength,and the P（M-Arg/NIPAAm）hydrogels showed a higher mechanical strength with an increasing of NIPAAm monomer,while P（M-Arg）hydrogel showed the lowest mechanical strength.3.Cumulative release of CHX preloaded hydrogels in vitro and antibacterial assessment showed that cumulative release rates of drug from PNIPAAm hydrogel was the fastest and then was P（M-Arg/NIPAAm）₁ hydrogel due to their sensitive to temperature at 37 oC,while the rate of P（M-Arg）hydrogel was the slowest which was owing to the most crosslinking bonds per unit volum and couldn’t be sensitive to temperature.The results of antibacterial test was in accordance with the cumulative release of drug.4.Antibacterial assessment of P（M-Arg/NIPAAm）hydrogels grafted PHMG which were preloaded CHX showed the zone of inhibition of the hydrogels against towards E.coli and S.aureus remained constant at 1-6 days during the antibacterial test,which revealed that the antibacterial property of hydrogels after grafting PHMG was prolonged and sustained.5.Protein adsorption experiment showed the BSA-FITC adsorption of PNIPAAm hydrogel was most: 104μg/cm² compared with control sample,P（M-Arg）with the least BSA-FITC adsorption of 25μg/cm²,the anti-protein adsorption of P（M-Arg/NIPAAm）hydrogels decreased with an increasing M-Arg,which indicated the introducing of M-Arg made the hydrogels possessing the property of anti-protein.6.Cell test showed that the surface of P（M-Arg/NIPAAm）₁ hydrogel had no cells,while the control sample（hydrogel D）had many cells after L929 fibroblast cells seeded on the surface of hydrogels and incubated in CO2 incubator for 72 h.And the results were line with protein adsorption test,which further demonstrated that zwitterionic M-Arg endowed hydrogels with properties of anti-fouling and anti-protein adsorpton.7.Cell toxicity test showed that the cell viability of the P（M-Arg/NIPAAm）and P（M-Arg）hydrogels was higher than PNIPAAm hydrogel,and the cell viability of P（M-Arg）hydrogel was the highest,which indicated that cell viability was improved with the amount of biocompatibility M-Arg increasing.8.Animal experiments showed that compared with the control group D hydrogel,the treatment group（P（M-Arg/NIPAAm）₁ hydrogel with CHX）was better to heal the wound,which showed that P（M-Arg/NIPAAm）₁ hydrogel had a significant effects on wound healing when applied in the field of dressing.