Protein growth factors loaded highly porous chitosan scaffold: A comparison of bone healing properties

• Published in: Materials Science & Engineering C Vol. 33; no. 3; pp. 1267 - 1275
• Main Authors: Nandi, Samit K., Kundu, Biswanath, Basu, Debabrata
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.04.2013
• Subjects: Animal model; Animals; Bone Morphogenetic Protein 2 - pharmacology; Bone remodeling; Chitosan - pharmacology; Female; Fluorescent Dyes - metabolism; Growth factor; Humans; Insulin-Like Growth Factor I - pharmacology; Male; Materials Testing; Microscopy, Electron, Scanning; Osteoblasts; Porosity; Porous chitosan; Rabbits; Radiography; Spectroscopy, Fourier Transform Infrared; Tibia - diagnostic imaging; Tibia - drug effects; Tibia - pathology; Tibia - ultrastructure; Tissue Scaffolds - chemistry; Wound Healing - drug effects; Animal model; Porous chitosan; Bone remodeling; Osteoblasts; Growth factor
• ISSN: 0928-4931; 1873-0191; 1873-0191
• DOI: 10.1016/j.msec.2012.12.025

Present study aimed to investigate and compare effectiveness of porous chitosan alone and in combination with insulin like growth factor-1 (IGF-1) and bone morphogenetic protein-2 (BMP-2) in bone healing. Highly porous (85±2%) with wide distribution of macroporous (70–900μm) chitosan scaffolds were fabricated as bone substitutes by employing a simple liquid hardening method using 2% (w/v) chitosan suspension. IGF-1 and BMP-2 were infiltrated using vacuum infiltration with freeze drying method. Adsorption efficiency was found to be 87±2 and 90±2% for BMP-2 and IGF-1 respectively. After thorough material characterization (pore details, FTIR and SEM), samples were used for subsequent in vivo animal trial. Eighteen rabbit models were used to evaluate and compare control (chitosan) (group A), chitosan with IGF-1 (group B) and chitosan with BMP-2 (group C) in the repair of critical size bone defect in tibia. Radiologically, there was evidence of radiodensity in defect area from 60th day (initiated on 30th day) in groups B and C as compared to group A and attaining nearly bony density in most of the part at day 90. Histological results depicted well developed osteoblastic proliferation around haversian canal along with proliferating fibroblast, vascularization and reticular network which was more pronounced in group B followed by groups C and A. Fluorochrome labeling and SEM studies in all groups showed similar outcome. Hence, porous chitosan alone and in combination with growth factors (GFs) can be successfully used for bone defect healing with slight advantage of IGF-1 in chitosan samples. ► Fabrication and characterization of porous chitosan with or without IGF-1 and BMP-2 ► Highly porous growth factor loaded chitosan studied in animal subjects for 3months ► Parameters studied: histopathology, radiology and fluorochrome labeling ► IGF-1 loaded porous chitosan found to be very effective for bone defect healing