Serum albumin‐coated bone allograft (BoneAlbumin) results in faster bone formation and mechanically stronger bone in aging rats

Abstract

Serum albumin‐coated bone allografts (BoneAlbumin) have successfully supported bone regeneration in various experimental models by activating endogenous progenitors. However, the effect of tissue aging, linked to declining stem cell function, has yet to be explicitly examined within the context of BoneAlbumin's regenerative capacity. Stem cell function was tested with an in vitro attachment assay, which showed that albumin coating increases stem cell attachment on demineralized bone surfaces in an aging cell population. Bone regeneration was investigated in vivo by creating critical size bone defects on the parietal bones of aging female rats. Demineralized bone matrices with and without serum albumin coating were used to fill the defects. Bone regeneration was determined by measuring the density and the size of the remaining bone defect with computed tomography (CT). Microcomputed tomography (MicroCT) and mechanical testing were performed on the parietal bone explants. In vivo CT and ex vivo microCT measurements showed better regeneration with albumin‐coated grafts. Additionally, the albumin‐coated group showed a twofold increase in peak fracture force compared with uncoated allografts. In the present study, serum albumin‐coated demineralized bone matrices successfully supported faster and functionally superior bone regeneration in aging rats. Because stem cell function, a key contributor of bone remodelling, decreases with age and serum albumin is an effective activator of endogenous progenitor cells, this method could be an effective and safe adjuvant in bone regeneration of aging adult and osteo‐compromised populations.

Enhancement and mechanisms of MC3T3‐E1 osteoblast‐like cell adhesion to albumin through calcium exposure

“…It was hypothesized that calcium impacts albumin to increase its overall bioactivity at bone injury sites eliciting the beneficial advantage seen with albumin on bone tissue healing 3,12,13,15,16 . Collectively in this study, MC3T3‐E1 cell adhesion is aided by calcium‐modified albumin and blocked by heat denatured albumin.…”

“…When albumin is delivered to injury sites in vivo , it demonstrates a beneficial impact on the bone‐healing process and it supports tissue regeneration 12–16 . For instance, coating freeze‐dried albumin onto mineralized bone allographs increased the adherence and proliferation of mesenchymal stem cells compared to albumin‐free controls, which was thought to be driven by the presence of albumin 16 .…”

“…For instance, coating freeze‐dried albumin onto mineralized bone allographs increased the adherence and proliferation of mesenchymal stem cells compared to albumin‐free controls, which was thought to be driven by the presence of albumin 16 . When albumin‐coated demineralized bone matrices were implanted in rats, they increased cell adhesion and led to the formation of mechanically stronger bone tissue over a shorter regeneration time compared to demineralized bone alone 12,15 . Together, albumin coating of both mineralized and demineralized bone grafts appeared to enhance bone repair.…”

Bioprinting and In Vitro Characterization of an Eggwhite-Based Cell-Laden Patch for Endothelialized Tissue Engineering Applications

“…Thus, the chances of integrating the implanted tissue patch with the surrounding healthy tissues improve. Albumin-based materials have been used in medicine and tissue engineering research in various areas such as skin [13], bone [21], lung [14], and heart [22]. For example, albumin-derived surgical sealant as a hemostatic adjunct for cardiac and vascular surgeries has shown excellent expansion and minimal inflammation within three months in pigs [23,24].…”

Antibacterial Albumin-Tannic Acid Coatings for Scaffold-Guided Breast Reconstruction

“…Human serum albumin (HSA) is a biodegradable and non-immunogenic protein that has long been studied as a coating component for the surface modification of biomaterials to minimize non-specific protein adsorption, improve cell adhesion and inhibit bacteria attachment to the surface of implants ( Tao et al, 2019 ). For instance, Horváthy et al (2019) showed that albumin is able to induce endogenous progenitor recruitment, promoting host cell attachment and proliferation for the support of bone remodeling, when coated onto bone grafts. In addition, several studies have demonstrated the ability of albumin coatings to inhibit gram-positive and gram-negative bacteria adhesion onto different material surfaces such as polymers and metals ( Kinnari et al, 2005 ; Ruiz et al, 2011 ).…”