Preparation And Application Of Hyaluronic Acid-based Electrospun Nanofibers

Hyaluronic acid (HA), a naturally occurring straight anionicpolysaccharide, widely exists in the extracellular matrix (ECM) ofconnective tissue. Fabricating HA nano-scale fibers has attracted muchattention for its remarkable applications in tissue engineering, woundhealing and release of drugs due to its biodegradability, biocompatibilityand wound healing ability. For the sake of extracting the application ofHA in Medicine, we have obtained pure HA nanofibers and HA basednanofiber membrane by electrospinning, which have been applied inwound healing and release of drugs. The main contents and conclusionsare described as follows:1. Pure HA nanofibers could be prepared at room temperature byelectrospinning HA solution. When HA powder was dissolved in thecombination solution of DW, FA and DMF, the hydrogen bonds and therigid alpha helix conformation of HA were partially disrupted.Rheological measurements indicated that FA could improve the HA chainentanglements by forming new hydrogen bonds with HA molecular afterthe hydrogen bonds and the rigid alpha helix conformation of HA weredisrupted. As a modified collector was incorporated into the process, theelectric field between the needle capillary and the collector was changedwhich facilitated the formation of pure HA nanofibers.2. Paclitaxel loaded porous nanofibers as mat potential application forchemotherapy against prostate cancer have been fabricated byelectrospinning. The result from SEM images showed that porousmorphology of the electrospinning nanofibers could be obtained byremove PEO via a selective dissolution technique with water. Theinteraction between the positively charged porous polymer (CS)nanofibers and negatively charged polymers (HA) encapsulated PTX inboth the surface of the porous fibers and the pores of the fibers.Fluorescence for electrospun nanofibers results demonstrated PTX wasdispersed inner of the nanofibers. The drug burst release behaviour wasmainly related with adsorption of the nanofibers. DU145prostate cancercells attached on the surfaces, but cell numbers decreased with increase of concentration of encapsulation PTX owing to the inhibition growth.3. The influence of solution properties on the electrospinnability ofPEC solutions was studied. The results showed that the increase ofconductivity and viscosity of the PECs solutions led to beads fibers, aswell as the poor electrospinnability. The fantastic influence of the PECssolution properties on the electrospinning and the morphology ofelectrospinning-fiber were considered as the result of the complicatedinteraction among two polyelectrolytes and solvent. DSC results showedthat molecular level complex was formed which endowed the PECs fiberswith properties applied for bioengineering and drug delivery.4. Polyelectrolyte based core-shell nanofibers could be prepared byelectrospinning a homogeneous solution of a polyelectrolyte (hyaluronicacid, sodium alginate and chitosan) and a synthetic polymer (PVA, PVPand PEO). In the process, polycation formed the shell layer, whilepolyanion formed the core. Electric field was the major effect of the phaseseparation. In the process, electric field enlarged the phase separationwindow (Cps~Cpf), which elongated the phase separation time fromseveral milliseconds to a few minutes, and core-shell structure nanofiberswere obtained. The polyelectrolyte based core-shell nanofibers membranewould show a potential application in biomedical field.