Editorial comment on: Vitrification of neat semen alters sperm parameters and DNA integrity.

Vol. 11 | No. 02 | MarchApril 2014 | UROLOGY JOURNAL Vitrification‎has‎brought‎about‎important‎changes‎in‎cryopreservation‎and‎human‎fertility‎preservation.‎Easiness‎and‎speed‎and‎no‎need‎for‎costly‎freezing‎technologies‎ are‎reasons‎for‎its‎rapid‎development.‎Vitrification‎is‎the‎solidification‎of‎a‎liquid‎ without‎crystallization.‎As‎cooling‎continues,‎however,‎the‎molecular‎waves‎in‎the‎liquid‎permeating‎the‎tissue‎decline.‎Finally,‎an‎"arrested‎liquid"‎state‎known‎as‎a‎glass‎is‎attained.‎Vitrification‎has‎been‎demonstrated‎to‎afford‎higher‎preservation‎for‎a‎number‎of‎cells,‎including‎ monocytes,‎ova‎and‎early‎embryos‎and‎pancreatic‎islets.(1) There‎are‎ a‎number‎of‎major‎ contests‎ for‎performing‎of‎vitrification‎ for‎ tissue‎engineered‎ medical‎products.‎Without‎adhering‎to‎these‎standards,‎certainly‎the‎process‎of‎vitrification‎ will‎fail.‎The‎first‎one‎is‎vitreous‎state.‎There‎is‎no‎explanation‎about‎vitreous‎state‎in‎this‎ study.‎Stability‎of‎the‎vitreous‎state‎is‎critical‎for‎the‎maintenance‎of‎vitrified‎tissue‎integrity‎ and‎viability.‎In‎present‎study‎the‎method‎of‎vitrification‎has‎not‎been‎explained‎in‎details‎and‎ it‎seems‎most‎of‎standards‎for‎vitrification‎have‎not‎been‎considered.‎Vitrification‎methods‎to‎ preservation‎have‎some‎of‎the‎limitations‎associated‎with‎conventional‎freezing‎methods.(2) First,‎both‎methods‎entail‎low‎temperature‎storage‎and‎transportation‎conditions.‎Neither‎can‎ be‎stored‎above‎their‎glass‎transition‎temperature‎for‎long‎without‎significant‎risk‎of‎product‎ damage‎due‎to‎inherent‎instabilities‎resulting‎to‎ice‎formation‎and‎growth.‎Both‎methods‎use‎ cryoprotectants‎with‎their‎associated‎problems‎and‎necessitate‎experienced‎technical‎support‎ during‎rewarming‎and‎cryoprotectant‎elution‎phases.‎The‎very‎high‎concentrations‎of‎cryoprotectants‎needed‎to‎facilitate‎vitrification‎are‎potentially‎toxic‎since‎the‎cells‎may‎be‎exposed‎to‎ these‎high‎concentrations‎at‎higher‎temperatures‎than‎in‎freezing‎methods‎of‎cryopreservation.‎ Cryoprotectants‎can‎kill‎cells‎by‎direct‎chemical‎toxicity,‎or‎indirectly‎by‎osmotically-induced‎ stresses‎during‎suboptimal‎addition‎or‎removal.(3)‎Upon‎complete‎achievement‎of‎warming,‎ the‎cells‎should‎not‎be‎exposed‎to‎temperatures‎above‎0oC‎for‎more‎than‎a‎few‎minutes‎before‎ the‎glass-forming‎cryoprotectants‎are‎removed.‎It‎is‎possible‎to‎employ‎vitrified‎products‎in‎ highly‎controlled‎environments,‎such‎as‎a‎commercial‎manufacturing‎facility‎or‎an‎operating‎ theater,‎but‎not‎in‎an‎outpatient‎office.‎There‎isn’t‎any‎data‎about‎above‎mentioned‎points‎in‎ this study.(4)‎Another‎issue‎is‎heat‎transfer.‎Heat‎transfer‎issues‎are‎the‎primary‎problem‎for‎ scaling‎up‎the‎successes‎in‎somewhat‎small‎tissue‎specimens‎to‎larger‎tissues‎and‎organs.‎The‎ limits‎of‎heat‎and‎mass‎transfer‎in‎bulky‎systems‎result‎in‎non-uniform‎cooling‎and‎leads‎to‎ stresses‎that‎might‎begin‎cracking.‎In‎fact,‎the‎higher‎cooling‎rates‎that‎facilitate‎vitrification‎ will‎typically‎lead‎to‎higher‎mechanical‎stresses.(5)‎In‎present‎study‎there‎is‎no‎information‎on‎ the‎used‎material‎properties‎of‎vitreous‎aqueous‎solutions.‎Material‎properties‎such‎as‎thermal‎ conductivity‎and‎fracture‎strength‎of‎vitreous‎aqueous‎solutions‎have‎many‎connections‎with‎ their‎inorganic‎analogues‎that‎happen‎at‎normal‎temperatures.‎Any‎material‎that‎is‎unrestricted‎ will‎undergo‎a‎change‎ in‎ size‎ (thermal‎ strain)‎when‎subjected‎ to‎a‎change‎ in‎ temperature.‎ Additional‎important‎issue‎that‎has‎not‎been‎addressed,‎is‎the‎stresses‎that‎arise‎to‎billet‎the‎ differential‎shrinkage.‎Thermal‎stress‎can‎definitely‎reach‎the‎produced‎strength‎of‎the‎frozen‎ tissue‎resulting‎in‎plastic‎deformations‎or‎fractures.(6)‎One‎more‎major‎obstacle‎for‎performing‎ Editorial comment on: Vitrification of Neat Semen Alters Sperm Parameters and DNA Integrity