ADHESION OF STALLION SPERMATOZOA ON POLY(ACRYLAMIDE) BASED HYDROGELS SURFACES: EFFECT OF HYDROGELIONIC CHARGE

EBEL BARRERA F; A C. LIAUDAT; BLOIS D; RODRIGUEZ N; RIVAROLA C; BOSCH P

Congreso; IV Reunión conjunta de sociedades de biología de la República Argentina; 2020

ADHESION OF STALLION SPERMATOZOA ON POLY(ACRYLAMIDE) BASED HYDROGELS SURFACES: EFFECT OF HYDROGELIONIC CHARGEEbel F1, Liaudat AC1, Blois D1, Rodríguez N1, Rivarola C2, Bosch P11INBIAS and 2IITEMA, FCEFQyN, UNRC - CONICET.e-mail: francisca.ebelb@gmail.comPolymeric hydrogels are soft materials used in many biotechnological applications. We demonstrated that poly(acrylamide) (PAAm) based hydrogels are devices for equine sperm selection; however, the molecular mechanisms responsible for this interaction are largely unknown. We hypothesized that the net ionic charge of the hydrogel surface may be involved in the sperm attachment. Therefore, we copolymerized acrylamide with 10% in moles of (3-acrylamidopropyl)trimethylammonium chloride (10%APTA, cationic monomer), N-[tris(hydroxymethyl)methyl] acrylamide (10%HMA, neutral monomer) and acrylic acid (10%AA, anionic monomer at pH>4) to achieve different ionic charges on the hydrogel surface. Then, we performed the sperm binding experiments in presence or absence of bovine serum albumin (BSA), a protein that is negatively charged at pH 7.4. For this purpose, each hydrogel was incubated in a culture dish containing sperm-TALP medium (pH 7.4) with and without BSA (6 mg/mL) at 37°C in 5% CO2 for 30 min. Finally, an aliquot of raw stallion sperm suspension was added (1x106 sperm/dish) and incubated at the same conditions mentioned before. Sperm incubated in culture dish without hydrogels served as controls. The percentage of sperm attached to the surfaces was determined as the difference between the number of sperm initially added into the culture dish and the recovered non-bound cells after incubation. Data (mean±SD) were analyzed by two way ANOVA/Bonferroni post-test; a P 10%HMA: 22.6±2.3% > control: 7.1±1.1%; P 10%APTA: 8.1±1.7% and control: 15.0±3.1%; P0.05). Additionally, in all experiments independent of BSA supplementation, spermatozoa attached to 10%AA and 10%HMA surfaces remained motile; whereas spermatozoa bound to 10%APTA surfaces were immotile. In conclusion, the ability of bonding between copolymeric hydrogels based on PAAm and spermatozoa is influenced by the hydrogel net ionic charge. The supplementation with BSA modifies the hydrogel superficial property and the ability of equine spermatozoa to bind on hydrogels, but without affecting the motility of bounded spermatozoa. This information might contribute to assisted reproduction in stallions with low reproductive efficiency.