Histopathology of Cryopreserved Bone Allo- and Isografts: Pretreatment with Dimethyl Sulfoxide

Abstract

Partial graft cell survival and enhanced graft revascularization have suggested fast freezing using the cryoprotective substance dimethyl sulfoxide (DMSO) as a promising means to improve the biologic function and immune tolerance of allograft bone. This study determines the presence of osteoblasts (cola(1)(I) mRNA), osteoclasts (TRAP), and cytotoxic T cells (CTLs; GrA mRNA) within pretreated bone grafts 12 days after transplantation. The grafts were transplanted either as isografts, allografts, or allografts in presensitized recipients. In fresh isografts, serving as control, well-formed blood vessels and the highest numbers of viable osteoblasts and osteoclasts were found. In fresh allografts, blood vessels were observed within the marrow cavity and the bone was partially covered by osteoblasts and osteoclasts accompanied by CTLs. In DMSO-pretreated frozen allografts, blood vessels together with osteoblasts were observed in three of five, but in none of five grafts frozen without DMSO. However, infiltration with CTLs was higher in DMSO-pretreated frozen allografts when compared to grafts frozen without DMSO. In presensitized allograft recipients, independent of the pretreatment, in none of the grafts were either blood vessels or osteoblasts found. Thus, fast cryopreservation of bone using DMSO improves vascularization and expression of cola(1)(I) mRNA (osteoblasts) after allografting when compared to cryopreservation alone, potentially improving graft incorporation. As these grafts were still invaded by CTLs, the long-term effect of DMSO pretreatment needs to be defined.

Clinical, Histologic, and Histomorphometric Analyses of Regenerated Bone in Maxillary Sinus Augmentation Using Fresh Frozen Human Bone Allografts

“…Despite the high standards of screening tests and procurement procedures for donors, there have been several reports 23–27 on the development of infectious diseases due to the transplantation of contaminated musculoskeletal allografts. However, allograft transplantation has been demonstrated to be safe because recent protocols have reduced graft antigenicity while preserving cell viability 19,28,29 . Fast freezing using the cryoprotective substance dimethyl sulfoxide (DMSO) has proven to be a promising means to improve immune tolerance of allograft bone and to enhance the biologic function by maintaining viable cells capable of giving rise to cell growth 28–30 …”

“…However, allograft transplantation has been demonstrated to be safe because recent protocols have reduced graft antigenicity while preserving cell viability 19,28,29 . Fast freezing using the cryoprotective substance dimethyl sulfoxide (DMSO) has proven to be a promising means to improve immune tolerance of allograft bone and to enhance the biologic function by maintaining viable cells capable of giving rise to cell growth 28–30 …”

“…The successful use of FFB in orthopedic surgery 19,28‐31 has paved the way to introduce this procedure in oral‐surgery and dental‐regenerative techniques to augment maxillary sites in case of insufficient bone volume before dental implant placement.…”

Effectiveness of fresh frozen and cryopreserved homologue iliac crest grafts used in sinus lifting: a comparative study

“…According to recent literature, we decided to use the CFFB because it showed an improved angiogenesis induction and enhanced immune tolerance compared with unprotected frozen grafts (Wingenfeld et al 2002); furthermore CFFB, thanks to dimethyl sulfoxide (DMSO) treatment; preserves some residual osteoblast cell viability (Egli et al 2003;Reuther et al 2005) which may be of importance in the early revascularization improving graft incorporation (Egli et al 2006).…”

Temporomandibular joint, skull base and mandibular ramus functional reconstruction with homologous bank tissue and free flap: A case report with 30 months follow‐up

“…After processing the bone graft was cryopreserved at 21608C in vapor of liquid nitrogen using the dimethylsulfoxide as a cryoprotectant to improve the biological function and immune tolerance of bone graft. 10 Once ascertained that all the serological and microbiological tests carried out and donor and tissue were negative, the bone graft was evaluated as suitable for transplant.…”