Scientists combined natural and artificial polymers to create materials with high biocompatibility

RUDN University researchers combined the advantages of artificial and natural polymers when creating nonwoven materials for use in medicine. The results are published in Polymers.

Using electrospinning technology, biodegradable polymers can be used to produce non-woven matrices consisting of fibers with a diameter of only a few microns. They can be used in the systems for targeted drug delivery, materials for closing wound surfaces and other biomedical products are created. At the same time, natural polymers are usually not strong enough, and artificial ones have reduced biocompatibility. To solve this problem, scientists combine natural and artificial polymers, but the optimal system has not yet been found.

“The low stability of natural polymers and the lack of biocompatibility of artificial polymers hinder the achievement of an optimal set of characteristics. These shortcomings can be corrected by combining natural and synthetic polymers. The synergy of the advantages of synthetic and natural polymers can be achieved through the effective combination of components and precise control over their ratio,” Timur Fatkhudinov, Director of the Research Institute of Molecular and Cellular Medicine, RUDN University.

The authors used two types of polymers: artificial biodegradable polycaprolactone and natural gelatin, which can significantly increase the hydrophilicity of the resulting material, and hence its biocompatibility . Previously, these polymers were combined at the final stage of creating fibrous matrices by chemically crosslinking gelatin and polycaprolactone skeleton, which led to a deterioration in the physical and mechanical properties of the materials or a very rapid washing out of gelatin in physiological solutions. Now the authors have proposed a new technology that makes it possible to combine polycaprolactone with gelatin even before the fiber electrospinning stage.

To covalently link the macromolecules of two polymers, chemists created NHS – functionalized polycaprolactone , capable of reacting with the amino groups of gelatin. After optimizing the conditions for electrospinning in the presence of a weak acid, a composite material was obtained, in which the gelatin content can be controlled quite accurately. The thus obtained fibrous material proved to be stable, resistant to hydrolysis, and its adhesive and physical-mechanical properties were significantly improved.

“Fibers based on a composite of polycaprolactone and gelatin are more stable and retain the integrity of the structure longer. But, more importantly, the mechanical characteristics of scaffolds made of such fibers are significantly different from those obtained by conventional “crosslinking” of gelatin and polycaprolactone scaffolds. Our results suggest that the modification of polymer molecules seems to be a realistic method that is too good to be ignored when developing protocols for electrospinning,” Professor Timur Fatkhudinov, Director of the Research Institute of Molecular and Cellular Medicine, RUDN University.