Preparation And In Vitro Degradation Properties On SA/CS Postoperative Anti-adhesion Film

In this study, polyelectrolyte sodium alginate (SA) and chitosan (CS) were used to prepared SA/CS bilayered film by means of electrostatic self-assembled in order to obtain the basic data of the film with expectation to be as postoperative anti-adhesion material. The method was different from methods such as blending or copolymerization. The advantage of bilayered film is that the two sides show different hydrophilicity, the hydrophilic side of the film can closely adhere to the wound while the hydrophobic side which is far away from the wound can well separate the wound and tissues around it.Scanning electron microscope (SEM) was used to obtain the section morphology of SA/CS bilayered films which were prepared by tape casting method and spin coating method respectively, tape casting method was chosen to perform the latter experiments.The contact angle, Fourier transform infrared spectroscopy (FTIR), dielectric properties, mechanical properties of the bilayered film and its monolayer film were tested and compared. A series of test results showed that the two side of the SA/CS bilayered film was different, the SA side was hydrophilic while the CS side was hydrophobic; The data of FTIR and dielectric spectroscopy properties convinced that SA/CS bilayered film was assembled by the electrostatic interaction between SA and CS; mechanical test result of SA/CS bilayered film showed that the tensile strength and elongation of it were43.03MPa and28.78%respectively which were a little lower than pure CS.The mass loss rate of the bilayered film was characterized which was gradually increased with the extension of the degradation time. When the degradation was performed in PBS for23days, the mass loss rate of SA/CS bilayered film was44.34%. Scanning electron microscopy (SEM) was used to obtain the morphology of the bilayered film, the change of the morphology was recorded almost dynamically. The degradation of the bilayered film in pH=7.4phosphate buffered saline (PBS) solution was studied dominatedly and the degradation mechanism was attempted to be given. The wet tensile strength of the SA/CS bilayered film was tested. It was showed that the tensile strength and elongation at break of the wet film were3.81MPa and79.33%respectively, while the degradation time was29days the wet tensile strength was1.21MPa which was lowered1.6MPa compared to the primary film. It was showed that SA/CS bilayered film can meet the requirements when played as physical barrier material.