RESUMO
The effects of a few synthetic polymers on the motility of human spermatozoa in vitro have been studied. An alternate copolymer of styrene and maleic anhydride, poly(S-MA), poly (styrene-maleic acid), poly(S-MC), poly(hydroxy-ethyl methacrylate-methacrylic acid) copolymer, poly(HEMA-MAC), poly(HEMA) homopolymer and poly(MAC) homopolymer were chosen for this purpose. It was found that all the carboxylic acid containing polymers are strong inhibitors of the motility of spermatozoa. Poly(HEMA) did not have any inhibitory effect on the motility of spermatozoa.
PIP: This paper describes the effects of selected synthetic polymers on the motility of human spermatozoa in vitro. The authors have developed a new mehtod of male fertility control that involves the use of an anionic hydrophilic polymer which when infected into the vas deferens, is precipitated and lowers the pH in the vicinity, thus killing the spermatozoa passing through the vas deferens. The results of this experiment indicate that carboxylic acid-containing polymers are strong inhibitors of sperm motility. Almost all sperm became immotile within 15 minutes after treatment with polymer (styrene-maleic acid) (S-MC) and polymer methacrylic acid (MAC). Polymer (HEMA-MAC), a copolymer containing roughly equal ratios of hydroxyethyl methacrylate and methacrylic acid, showed inhibitory action, but it took 30 minutes for 100% immotility to be achieved. The stronger inhibition of motility observed with poly (S-MC) compared with poly (HEMA-MAC) is attributed to the presence in the former of 2 carboxylic groups on adjacent carbon atoms. It is possible that low pH environment created by ionization of carboxyl groups fixed in the polymer matrix is responsible for killing the spermatozoa. Hydrogen ion concentration is considered to be a key factor in influencing the motility, viability, and metabolism of spermatozoa. Poly (HEMA), containing only hydroxyl groups, did not have any inhibitory effect.
