In vitro and in vivo evaluation of the marine sponge skeleton as a bone mimicking biomaterial

• Published in: Integrative biology (Cambridge) Vol. 7; no. 2; pp. 25 - 262
• Main Authors: Nandi, Samit K, Kundu, Biswanath, Mahato, Arnab, Thakur, Narsinh L, Joardar, Siddhartha N, Mandal, Biman B
• Format: Journal Article
• Language: English
• Published: England 01-02-2015
• Subjects: 3T3 Cells; Animals; Bone Morphogenetic Protein 2 - administration & dosage; Bone Remodeling; Bone Substitutes - chemistry; Female; Humans; In Vitro Techniques; Insulin-Like Growth Factor I - administration & dosage; Male; Materials Testing; Mice; Microscopy, Electron, Scanning; Osteogenesis; Porifera - chemistry; Porifera - ultrastructure; Rabbits; Recombinant Proteins - administration & dosage; Spectroscopy, Fourier Transform Infrared; Tissue Engineering - methods; Tissue Scaffolds - chemistry
• ISSN: 1757-9694; 1757-9708
• DOI: 10.1039/c4ib00289j

This investigation was carried out to identify and characterize marine sponges as potential bioscaffolds in bone tissue engineering. The marine sponge (
Biemna fortis
) samples were collected from the rocky intertidal region of Anjuna, Goa, India, freeze-dried and converted to pure cristobalite at low temperature. After thorough evaluation of sponge samples by DTA-TGA thermography, XRD, FTIR, SEM and cell cytotoxicity by MTT assay, bare sponge scaffolds were fabricated by firing at 1190 °C. These scaffolds were loaded with growth factors (IGF-1 and BMP-2), checked for quasi-dynamic
in vitro
release kinetics and finally implanted into femoral bone defects in rabbits for up to 90 days, by keeping an empty defect as a control. The
in vivo
bone healing process was evaluated and compared using chronological radiology, histology, SEM and fluorochrome labeling studies. SEM revealed that the sponge skeleton possesses a collagenous fibrous network consisting of highly internetworked porosity in the size range of 10-220 μm. XRD and FTIR analysis showed a cristobalite phase with acicular crystals of high aspect ratio, and crystallinity was found to increase from 725 to 1190 °C. MTT assay demonstrated the non-cytotoxicity of the samples. A combination of burst and sustained release profile was noticed for both the growth factors and about 74.3% and 83% total release at day 28. In the radiological, histological, scanning electron microscopy and fluorochrome labeling analysis, the IGF-1 impregnated converted sponge scaffold promoted excellent osseous tissue formation followed by the BMP-2 loaded and bare one. These observations suggest that the marine sponge alone and in combination with growth factors is a promising biomaterial for bone repair and bone augmentation.
This investigation was carried out to identify and characterize marine sponges as potential bioscaffolds in bone tissue engineering.