Treatment of Critical-Size Femoral Bone Defects with Chitosan Scaffolds Produced by a Novel Process from Textile Engineering

Abstract

The purpose of this study was to investigate, in vitro and in vivo, the suitability of chitosan (CHS) scaffolds produced by the net-shape-nonwoven (NSN) technology, for use as bone graft substitutes in a critical-size femoral bone defect in rats. For in vitro investigations, scaffolds made of CHS, mineralized collagen (MCM), or human cancellous bone allograft (CBA) were seeded with human telomerase-immortalized mesenchymal stromal cells (hTERT-MSC), incubated for 14 days, and thereafter evaluated for proliferation and osteogenic differentiation. In vivo, CHS, MCM and CBA scaffolds were implanted into 5 mm critical-size femoral bone defects in rats. After 12 weeks, the volume of newly formed bone was determined by microcomputed tomography (µCT), while the degree of defect healing, as well as vascularization and the number of osteoblasts and osteoclasts, was evaluated histologically. In vitro, CHS scaffolds showed significantly higher osteogenic properties, whereas treatment with CHS, in vivo, led to a lower grade of bone-healing compared to CBA and MCM. While chitosan offers a completely new field of scaffold production by fibers, these scaffolds will have to be improved in the future, regarding mechanical stability and osteoconductivity.

Experimental Early Stimulation of Bone Tissue Neo-Formation for Critical Size Elimination Defects in the Maxillofacial Region

“…Numerous publications on bone regeneration after the formation of a critical-size bone cavity show that self-implantation of a multilayer microfiber of chitosan with a molecular weight of 200-300 kDa and a degree of deacetylation of 90% into a 5 mm femoral defect using mesenchymal stem cells differentiated in osteoblasts within 12 weeks does not lead to the final filling of the defect. Compared with the use of a bone allograft, the results of the regeneration volume were 1.5 times lower (p < 0.01) [49]. A blinded assessment revealed a mean score of 4.4 ± 1.3 for the implants made of chitosan and 5.9 ± 0.8 for bone allograft.…”

Mesenchymal Stromal/Stem Cell (MSC)-Based Vector Biomaterials for Clinical Tissue Engineering and Inflammation Research: A Narrative Mini Review

“…For example, an increase in porosity is associated with a concomitant decrease in mechanical stability. 73 Additionally, chitosan hydrogel-loaded MSC-derived extracellular vesicles obtaining by extracellular vesicles mixed with an equal volume of a 2% CS solution showed good performance in skin injury repair models. 74 They increase the proliferation, migration, and expression of anti-aging-related genes in naturally senescent fibroblasts and promote extracellular matrix regeneration of senescent fibroblasts by decreasing MMPS levels and increasing TIMPs levels.…”

Functionalization of biomimetic mineralized collagen for bone tissue engineering

“…Biomimetic materials, such as MC, are engineered to mimic the first two levels of this hierarchy - the chemical composition and structural elements [ 27 ]. They possess excellent biocompatibility, biodegradability, low antigenicity, and compositional and structural flexibility, which promote adhesion, proliferation, and differentiation of pre-osteoblasts or stem cells in vitro , as well as cell migration ratios [ 21 , [28] , [29] , [30] , [31] ]; enhances osteogenesis and angiogenesis in vivo ; and promotes the repair of bone defects and the osseointegration of implants [ [31] , [32] , [33] , [34] , [35] , [36] ]. Compared with pure collagen, HA, and tricalcium phosphate (TCP) bone scaffold materials, MC can better promote osteogenic differentiation, induce ECM secretion and mineralization, stimulate angiogenesis, and ultimately promote osteogenesis [ 24 , 28 , [37] , [38] , [39] , [40] , [41] ].…”