Preparation And Properties Of Functional Alginate Fiber

In recent years,polymer biomaterials have been further studied,clinical medical dressings products are updated constantly,whose types,properties and functions are developing diversifiedly.Alginic acid and its derivatives performs excellent characteristics,which can be applied in medical dressings matrix suitably.However,the antibacterial activity of pure calcium alginate fiber is weak in inhibiting the growth of wound infection bacteria,so it is significant to study and improve the antibacterial activity of alginate dressings greatly.Functional alginate fiber has become a hotspot to research as a precursor of functional medical dressings.To improve the antibacterial activity of alginate dressings and adapt to the complex wound environment,this study takes medical alginate as matrix material and wet blending technology to manufacte functional alginate fiber loaded with chlorhexidine gluconate?CHG?,which is expected to be widely used in the field of medical biological dressings.Meanwhile,HPLC combined with liquid-liquid extraction for the determination the actual content of CHG loaded in alginate fiber was established successfully.The effects of content of CHG-loaded on the morphology,hygroscopicity,drug release,antibacterial activity and biocompatibility of calcium alginate fiber were investigated.Ulteriorly,Discovery studio was applied to simulate the optimal conformation of fibrous matrix block loading CHG,as well as the relative Dynamics of Standard Dynamics Cascade Analyze Trajectory and Solvation were discussed.The results were showed as follows:?1?Preparation and determination of CHG-calcium alginate fiber: calcium alginate fiber with three kinds of drug-loading were prepared.HPLC combined with liquid-liquid extraction to determine the content of CHG loaded in alginate fiber was established successfully.The effects of mobile phase composition and p H values of mobile phase on peak emergence of chlorhexidine gluconate and chlorhexidine acetate were investigated.C18 chromatographic column was used for gradient elution.Methanol-formic acid solution?p H=3.5?was used as mobile phase.The results demonstrated that the target shows a good linear relationship with correlation coefficients greater than 0.999.The average recovery rate was 94.95 % and the RSD was 2.5 %.The actual content of CHG loaded in alginate fiber were 0 mg/g,22.97 mg/g and 79 mg/g,which named 2^#fiber,3^#fiber and 4^#fiber respectively.?2?Morphology characterization and antibacterial activity of CHG-calcium alginatefiber: SEM,FTIR and DSC were used to corroborate the drug coating.Compared with pure calcium alginate fiber,the shallow grooves and wide folds appear on the surface of drugloaded calcium alginate fiber.N-H of CHG molecule forms hydrogen bond with free hydrogen in alginate molecule,and its characteristic vibration is 1573 cm^-1.The antibacterial rate of 3^# and 4^# fiber to S.aureus and P.aeruginosa reached 84.07%,97.04%and 67.80%,90.75%,respectively,was higher than that of 2^# fiber significantly.With the increase of CHG loading,the lethal effect of loaded calcium alginate fiber was obvious gradually.?3?Cytotoxicity and others properties of CHG-calcium alginate fiber: CHG-loaded alginate fiber were bloated and decomposed into numbers of small fibrous fragments in PBS,and released drugs through gelation in A solution,However,alginate fiber with higher CHG content remained fibrous state in solution A.The drug release rates of 3^# fiber and 4^#fiber were 28.5% and 53% in PBS,92% and 47.6% in A solution,respectively.The CHG-calcium alginate fiber promote the growth of L-929 cells effectively,and the hygroscopicity increases slightly,which is related to the binding conformation of alginate matrix-CHG.?4?Simulation by Discovery Studio of CHG-calcium alginate matrix blocks: Through the simulation by DS,the lowest energy conformation of three blocks were optimized out with stronger stability.The results indicated that the bond energy of the target structure decreases with the increase of the torsion energy.The RMSD value of target decreases with the simulation process,indicating that the repeatability of the conformation was increased.The RMSF value of multi-M block has the largest mean fluctuation interval due to the structural differences of G perssa and M perssad.The transition energy of the target block was greatly reduced by solvent effect.