[Study on the prevention of postoperative intraperitoneal adhesion of rat with PLGA/PEG electrospun polymer membrane]

Objective: Adopting poly- L-lactic/glycolic acid (PLGA) and polyethylene glycol (PEG) as the material to fabricate PLGA/PEG electrospun polymer membrane by electrospinning technology. And to study its preventive effect on postoperative intraperitoneal adhesion of rat.

Methods: PLGA and PEG were mixed at the ratio of 19∶1( M/M), then dissolved in organic solvent. The PLGA/PEG electrospun polymer membrane was prepared by electrospinning technology, and then the gross observation and scanning electron microscope observation were taken. Fifty-four Sprague Dawley rats (weighing, 180-200 g), were randomly divided into 3 groups. The rats in control group ( n=6) were left intact. The rats in model group ( n=24) and PLGA/PEG group ( n=24) were treated with the method of mechanical injury of the cecal serosa in order to establish the intraperitoneal adhesion models; then the PLGA/PEG electrospun polymer membrane was used to cover the wound in PLGA/PEG group, but was not in the model group. The intraperitoneal adhesion in PLGA/PEG group and model group were observed at 3 days, 1 week, 2 weeks, and 8 weeks after operation, and the adhesion degree was assessed according to the self-generated standard. The degradation of PLGA/PEG electrospun polymer membrane was also observed in PLGA/PEG group. At each time point, the rats were harvested for histological observation. All the above indexes were compared with the control group.

Results: Using the electrospinning technology, PLGA/PEG electrospun polymer membrane was prepared successfully. PLGA/PEG electrospun polymer membrane was white and opaque, with soft texture. Scanning electron microscopy observation showed that PLGA/PEG electrospun polymer membrane was mainly composed of disorderly staggered fibers, with microporous structure. All rats survived to the end of the experiment. Gross observation showed that PLGA/PEG electrospun polymer membrane gradually degraded after implantation in vivo, and the adhesion degree in PLGA/PEG group was significantly lower than that in model group ( P<0.05), but it had not yet reached to the level of the control group ( P<0.05). Histological observation showed that the proliferation of cecal fibrous connective tissue was slower in PLGA/PEG group than in model group, and adhesion severity significantly decreased, only with a small amount of inflammatory cell infiltration. Nevertheless, it was not up to the level of the control group.

Conclusion: PLGA/PEG electrospun polymer membrane can effectively prevent postoperative intraperitoneal adhesion of rat, and has good biodegradability.