Mineralized collagen scaffold bone graft accelerate the osteogenic process of HASCs in proper concentration

Analysis of the Effect of Human Type I Collagen-Derived Peptide on Bone Regenerative Capacity and Comparison with Various Collagen Materials In Vivo

Background and Objectives: Autologous bone grafting is the first choice for reconstructive surgery in bone defects due to trauma or malignant tumors. However, there is an increasing demand for minimally invasive alternatives involving bone regeneration using artificial materials. Biomimetic materials that replicate the body's microscopic structure, such as Cellnest®, are gaining attention. Cellnest is a xeno-free recombinant peptide based on human type I collagen, containing a rich Arg-Gly-Asp (RGD) motif related to cell adhesion. The aim of this study was to compare the effects of Cellnest with existing collagen materials (Pelnac®, Integra®, Terudermis®) on bone regeneration and elucidate the underlying mechanisms. Materials and Methods: In vivo experiments involved a rat model of calvarial bone defects, in which Cellnest and other collagen materials were implanted into the defect area. Bone formation was assessed after 4 weeks using micro-computed tomography (micro-CT) and histological analysis. In vitro experiments included the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), adhesion, and migration assays, and a real-time polymerase chain reaction using rapidly expanding cells (RECs) to explore the mechanisms of Cellnest's bone regenerative capacity. Results: The micro-CT analysis showed that the regenerated bone area was significantly greater in the Cellnest group (72.3%) than in the Pelnac® (25.5%), Integra® (31.6%), and Terudermis® (38.3%) groups. The histological analysis confirmed similar trends, with Cellnest showing 42.2% bone regeneration, outperforming the other materials. The in vitro assays revealed that Cellnest promoted cell proliferation, adhesion, and migration. Gene expression analysis demonstrated that Cellnest significantly increased the levels of the bone formation markers ALP and COL1. Conclusions: Cellnest, a human type I collagen-like peptide rich in RGD motifs, enhances bone regeneration by promoting MSC adhesion and migration, and bone formation-related gene expression. The findings suggest its potential as an effective material for bone defect reconstruction.

Functionalization of biomimetic mineralized collagen for bone tissue engineering

Mineralized collagen (MC) is the basic unit of bone structure and function and is the main component of the extracellular matrix (ECM) in bone tissue. In the biomimetic method, MC with different nanostructures of neo-bone have been constructed. Among these, extra-fibrous MC has been approved by regulatory agencies and applied in clinical practice to play an active role in bone defect repair. However, in the complex microenvironment of bone defects, such as in blood supply disorders and infections, MC is unable to effectively perform its pro-osteogenic activities and needs to be functionalized to include osteogenesis and the enhancement of angiogenesis, anti-infection, and immunomodulation. This article aimed to discuss the preparation and biological performance of MC with different nanostructures in detail, and summarize its functionalization strategy. Then we describe the recent advances in the osteo-inductive properties and multifunctional coordination of MC. Finally, the latest research progress of functionalized biomimetic MC, along with the development challenges and future trends, are discussed. This paper provides a theoretical basis and advanced design philosophy for bone tissue engineering in different bone microenvironments.

A Review on Three-Dimensional Printed Silicate-Based Bioactive Glass/Biodegradable Medical Synthetic Polymer Composite Scaffolds

In recent years, tissue engineering scaffolds have turned into the preferred option for the clinical treatment of pathological and traumatic bone defects. In this field, silicate-based bioactive glasses (SBGs) and biodegradable medical synthetic polymers (BMSPs) have attracted a great deal of attention owing to their shared exceptional advantages, like excellent biocompatibility, good biodegradability, and outstanding osteogenesis. Three-dimensional (3D) printed SBG/BMSP scaffolds can not only replicate the mechanical properties and microstructure of natural bone but also degrade in situ after service and end up being replaced by regenerated bone tissue in vivo. This review first consolidates the research efforts in 3D printed SBG/BMSP scaffolds, and then focuses on their composite mechanism. This review may help to provide a fresh perspective for SBG/BMSP composite system in bone regeneration.

Characterization of Tissue Scaffolds Using Synchrotron Radiation Microcomputed Tomography Imaging

Distinguishing from other traditional imaging, synchrotron radiation microcomputed tomography (SR-μCT) imaging allows for the visualization of three-dimensional objects of interest in a nondestructive and/or in situ way with better spatial resolution, deep penetration, relatively fast speed, and/or high contrast. SR-μCT has been illustrated promising for visualizing and characterizing tissue scaffolds for repairing or replacing damaged tissue or organs in tissue engineering (TE), which is of particular advance for longitudinal monitoring and tracking the success of scaffolds once implanted in animal models and/or human patients. This article presents a comprehensive review on recent studies of characterization of scaffolds based on SR-μCT and takes scaffold architectural properties, mechanical properties, degradation, swelling and wettability, and biological properties as five separate sections to introduce SR-μCT wide applications. We also discuss and highlight the unique opportunities of SR-μCT in various TE applications; conclude this article with the suggested future research directions, including the prospective applications of SR-μCT, along with its challenges and methods for improvement in the field of TE.