Browsing by Author "Shenoy, Sachin J."

Now showing 1 - 3 of 3
  • Item
    Reconstruction of goat femur segmental defects using triphasic ceramic-coated hydroxyapatite in combination with autologous cells and platelet-rich plasma
    (ACTA BIOMATERIALIA, 2009)
    Segmental bone defects resulting from trauma or pathology represent a common and significant clinical problem. In this study, a triphasic ceramic (calcium silicate, hydroxyapatite and tricalcium phosphate)-coated hydroxyapatite (HASi) having the benefits of both HA (osteointegration, osteoconduction) and silica (degradation) was used as a bone substitute for the repair of segmental defect (2 cm) created in a goat femur model. Three experimental goat femur implant groups - (a) bare HASi, (b) osteogenic-induced goat bone marrow-derived mesenchymal stem cells cultured HASi (HASi + C) and (c) osteogenic-induced goat bone marrow-derived mesenchymal stem cells cultured HASi + platelet-rich plasma (HASi + CP) - were designed and efficacy performance in the healing of the defect was evaluated. In all the groups, the material united with host bone without any inflammation and an osseous callus formed around the implant. This reflects the osteoconductivity of HASi where the cells have migrated from the cut ends of host bone. The most observable difference between the groups appeared in the mid region of the defect. In bare HASi groups, numerous osteoblast-like cells could be seen together with a portion of material. However, in HASi + C and HASi + CP, about 60-70% of that area was occupied by woven bone, in line with material degradation. The interconnected porous nature (50-500 mu m), together with the chemical composition of the HASi, facilitated the degradation of HASi, thereby opening up void spaces for cellular ingrowth and bone regeneration. The combination of HASi with cells and PRP was an added advantage that could promote the expression of many osteoinductive proteins, leading to faster bone regeneration and material degradation. Based on these results, we conclude that bare HASi can aid in bone regeneration but, with the combination of cells and PRP, the sequence of healing events are much faster in large segmental bone defects in weight-bearing areas in goats. (c) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
  • Item
    Tissue regeneration and repair of goat segmental femur defect with bioactive triphasic ceramic-coated hydroxyapatite scaffold
    (JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A, 2009)
    Bone tissue engineering which is a developing and challenging field of science, is expected to enhance the regeneration and repair of bone lost from injury or disease and ultimately to gain its aesthetic contour. The objective of this study was to fabricate a tissue-engineered construct in vitro using a triphasic ceramic-coated hydroxypatite (HASi) in combination with stem cells and to investigate its potential in healing segmental defect in goat model. To accomplish this attempt, mesenchymal stern cells isolated from goat bone marrow were seeded onto HASi scaffolds and induced to differentiate into the osteogenic lineage in vitro. Scanning electron microscopy and light microscopy revealed adhesion and spread-out cells, which eventually formed a cell-sheet like canopy over the scaffold. Cells migrated and distributed themselves within the internal voids of the porous ceramic. Concurrently, the neoosteogenesis of the tissue-engineered construct was validated in vivo in comparison with bare HASi (without cells) in goat femoral diaphyseal segmental defect (2 cm) at 4 months postimplantation through radiography, computed tomography, histology, histomorphometry, scanning electron microscopy and inductively coupled plasma spectrometry. Good osteointegration and osteoconduction was observed in bare and tissue-engineered HASi. The performance of tissue-engineered HASi was better and faster which was evident by the lamellar bone organization of newly formed bone throughout the defect together with the degradation of the material. On the contrary with bare HASi, immature woven bony bridges still intermingled with scattered small remnants of the material was observed in the mid region of the defect at 4 months. Encouraging results from this preclinical study has proved the capability of the tissue-engineered HASi as a promising candidate for the reconstruction of similar bony defects in humans. (C) 2008 Wiley Periodicals, Inc. J Biomed Mater Res 91A: 855-865, 2009
  • Item
    Treatment of Goat Femur Segmental Defects with Silica-Coated Hydroxyapatite-One-Year Follow-Up
    (TISSUE ENGINEERING PART A, 2010)
    Segmental bone defects caused by tumor resections, trauma, and skeletal abnormalities such as osteomyelitis remain a major problem in orthopedics because of the lack of predictability in attaining functional bone after the treatment. The objective of this study was to propose an indigenous porous biodegradable triphasic ceramic (calcium silicate, tricalcium phosphate, and hydroxyapatite [HA])-coated HA (core) (HASi) for the repair of such segmental defects. With respect to the synthesis of HASi, HA blocks were prepared by wet precipitation, dipped in silica sol (sol gel method), sintered at 1200 degrees C, polished in the form of hollow cylinder (2 cm long with an outer and inner diameter of 2 cm and 7 mm, respectively), and implanted into a 2-cm segmental defect created in the goat femur diaphysis. This study prolonged for 12 uneventful months and thereafter neo-osteogenesis in par with material degradation was analyzed through radiography, histology, histomorphometry, scanning electron microscope (SEM)-energy dispersive spectrum, micro-computed tomography, and inductively coupled plasma spectrometry. HASi proved to be osteoconductive, osteointegrative, and degradative in nature, without the intervention of fibrous tissue formation at the defect site. Histologically, the newly formed bone reorganized, mineralized, and attained the appearance and contour of the original femoral diaphysis in 1 year. The interconnected porous structure with silica composition aided progressive bone regeneration and repair in par with degradation of the material. Thus the study proposed the possibility of using HASi as a suitable material in clinical orthopedic reconstructive surgery, which remains a formidable challenge.