Criteria, Challenges, and Opportunities for Acellularized Allogeneic/Xenogeneic Bone Grafts in Bone Repairing

Abstract

As bone grafts become more commonly needed by patients and as donors become scarcer, acellularized bone grafts (ABGs) are becoming more popular for restorative purposes. While autogeneic grafts are reliable as a gold standard, allogeneic and xenogeneic ABGs have been shown to be of particular interest due to the limited availability of autogeneic resources and reduced patient well-being in long-term surgeries. Because of the complete similarity of their structures with native bone, excellent mechanical properties, high biocompatibility, and similarities of biological behaviors (osteoinductive and osteoconductive) with local bones, successful outcomes of allogeneic and xenogeneic ABGs in both in vitro and in vivo research have raised hopes of repairing patients' bone injuries in clinical applications. However, clinical trials have been delayed due to a lack of standardized protocols pertaining to acellularization, cell seeding, maintenance, and diversity of ABG evaluation criteria. This study sought to uncover these factors by exploring the bone structures, ossification properties of ABGs, sources, benefits, and challenges of acellularization approaches (physical, chemical, and enzymatic), cell loading, and type of cells used and effects of each of the above items on the regenerative technologies. To gain a perspective on the repair and commercialization of products before implementing new research activities, this study describes the differences between ABGs created by various techniques and methods applied to them. With a comprehensive understanding of ABG behavior, future research focused on treating bone defects could provide a better way to combine the treatment approaches needed to treat bone defects.

A Randomized Controlled Trial: Short-Segment Posterior Fixation and Transpedicular Bone Grafting combined with rhBMP-2 for the Treatment of Thoracolumbar Burst Fracture

“…The mechanism by which allogeneic bone mixed with rhBMP-2 promotes fracture healing may be that allogeneic bone provides a scaffolding structure in the injured vertebrae, which promotes migration and proliferation of osteoblasts in addition to helping to maintain the stability of the fracture site [25] . In contrast, rhBMP-2 mainly promotes the differentiation of stem cells, stimulates the proliferation of cartilage and osteoblasts, accelerates the rate of new bone tissue generation, improves bone matrix protein synthesis, promotes angiogenesis, and provides the nutrients and oxygen needed in the fracture healing process, thus facilitating the process of fracture healing (Fig.…”

Applications of Degradable Hydrogels in Novel Approaches to Disease Treatment and New Modes of Drug Delivery

“…Nevertheless, it has not been widely used in clinical practice because of the possibility of latent infection at the donor site and chronic pain [59]. The clinical application of allogeneic bone transplantation has also been severely hindered by limited donor sources, immune rejection, and potential disease transmission [60]. Bone tissue engineering is a multidisciplinary technology that combines osteoblasts, osteoblast-related factors, and scaffold materials, and it provides a new strategy for the regeneration and repair of bone defects [61].…”

Advances and Trends of Photoresponsive Hydrogels for Bone Tissue Engineering

“…6 Noninvasive therapeutic approaches include biophysical stimulation and pulsed electromagnetic field (PEMF) therapy. Surgical intervention is considered one of the most effective solutions for treating bone defects, including the use of bone grafts, 7 the Masquelet technique, 8 the Ilizarov technique, 9 etc. Bone grafts can be classified as natural or synthetic, with autografts, allografts, or xenografts falling into the former category.…”