Study Of Improved Rapid Cryopreservation Of Small Numbers Of Human Spermatozoa

BACKGROUND:Cryopreservation of human spermatozoa in small number is one of the important technical guarantees for the treatment of male infertility.Patients with obstructive azoospermia or oligospermia need a certain amount of sperm to ensure the completion of intracytoplasmic sperm injection(ICSI).This type of male infertility,whose sperm is hard to harvest,requires repeated attempts of sperm cryopreservation or surgical procedure.Pain,inflammation,blood testis barrier damage caused by multiple testicular puncture operations,anti-sperm antibody production,scar formation,sexual dysfunction and other adverse complications will be avoided,and the risk of sperm availability be reduced on the day of egg retrieval,if the sperm can be cryopreservated at the time of diagnosis.In addition,since microdissection testicular sperm extraction(Micro-TESE)for non-obstructive azoospermia has emerged in recent years,technological improvement for cryopreservation of human spermatozoa in small number is more urgent.At present,the cryopreservation of small number human spermatozoa is,however,difficult and its effect is not satisfactory enough,and there has been no well accepted method so far.OBJECTIVE:Exploring a new and improved repid method for small numbers of sperm cryopreservation,provide assistance for the ICSI technique in patients with severe oligoospermia infertility,reduces adverse outcomes due to insufficient available sperm count in assisted reproductive technology(ART).METHODS:In the first part of this study,according to the theory of sperm cryopreservation,the use of safe embryos or sperm cryopreservation materials to design relatively safe and efficient improved repid cryopreservation carrier.Through sperm cryopreservation Cryobiology verification,optimization of cryopreservation resuscitation program parameters,and repeated repeated experiment evaluation,a safe and efficient new method of rare sperm freezing is established,Preliminary judgment of its feasibility,And compared with the traditional repid sperm cryopreservation method used good-quality sperm recovery.In the second part of the study,in order to prove the clinical application value of the improved rapid cryopreservation method to small numbers of sperm,the effectiveness and safety of mixed sperm diluted to a concentration of(1?2)×10~6/ml were used.The research is divided into two stages:the experimental analysis of oligoospermia and small numbers of sperm with normal quality.Principal by comparing with the traditional rapid cryopreservation scheme,evaluate the changes in sperm motility,survival rate,DNA fragmentation,acrosomal enzyme activity and normal morphology rate after cryotherapy.RESULTS:The first part of the establishment of a rapid sperm improvement and rapid cryopreservation program:A new type of carrier made of polypropylene straw and embryo special polypropylene sheet.Compared with traditional methods,the thickness of the dielectric material is thinner,and the temperature conduction rate is faster.2?l droplet size,3 cm away from the liquid nitrogen plane,fumigation for 2 min,cryopreservation scheme is the best freezing parameter condition;The high recovery rate of sperm freezing recovery,recovery rate is high of good sperm,up to 75%,higher than traditional methods.The second part of the comparative study of the improved rapid cryopreservation method of human rare sperm and traditional methods found that the recovery of mobile sperm freezing is higher.The damage to normal sperm morphology,membrane structure,sperm nucleus structure,and sperm acrosome function is less than traditional rapid freezing methodsCONCLUSION:Improved carrier for rapid cryopreservation has certain advantages for small numbers of sperm cryopreservation,which is worthy of further study.