Tackling the Problem of Tendon Adhesions: Physical Barriers Prepared from α-Amino Acid-Based Poly(ester amide)s

In this work, electrospun membranes of α-amino acid based poly(ester amide)s (AAA-PEAs) from L-alanine (PEA_ala) or L-phenylalanine (PEA_phe) were successfully prepared to be used as physical barriers in the orthopedic field. Also, blends of these two polymers were used in different weight ratios (25:75, 50:50 and 75:25) to obtain physical barriers with different properties. All membranes had a suitable pore size to prevent fibroblast infiltration, and their porosity and permeability values were in a range that allowed the passage of nutrients. The membrane made from a blend of 25%wt of PEA_ala and 75% wt of PEA_phe showed the highest value of swelling capacity, suggesting a higher lubricant feature. The same membrane suffered a more pronounced degradation, as evidenced by the in vitro enzymatic degradation tests. All membranes showed suitable toughness values, a crucial property with regard to application. In vitro cytotoxicity tests performed with a NIH3T3 fibroblast cell line revealed decreased cell viability after 7 days, suggesting that these membranes are not ideal substrates to promote fibroblast adhesion and proliferation. These membranes as physical barriers represent a significant advance in the field given the limited literature on electrospun AAA-PEAs and their use to prevent tendon adhesion.