Browsing by Author "Basu, B"

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    An X-ray micro-fluorescence study to investigate the distribution of Al, Si, P and Ca ions in the surrounding soft tissue after implantation of a calcium phosphate-mullite ceramic composite in a rabbit animal model
    (JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE, 2011) Martin, RA; Jaffer, Z; Tripathi, G; Nath, S; Mohanty, M; FitzGerald, V; Lagarde, P; Flank, AM; Stamboulis, A; Basu, B
    Synthetic calcium phosphates, despite their bioactivity, are brittle. Calcium phosphate-mullite composites have been suggested as potential dental and bone replacement materials which exhibit increased toughness. Aluminium, present in mullite, has however been linked to bone demineralisation and neurotoxicity: it is therefore important to characterise the materials fully in order to understand their in vivo behaviour. The present work reports the compositional mapping of the interfacial region of a calcium phosphate-20 wt% mullite biocomposite/soft tissue interface, obtained from the samples implanted into the long bones of healthy rabbits according to standard protocols (ISO-10993) for up to 12 weeks. X-ray micro-fluorescence was used to map simultaneously the distribution of Al, P, Si and Ca across the ceramic-soft tissue interface. A well defined and sharp interface region was present between the ceramic and the surrounding soft tissue for each time period examined. The concentration of Al in the surrounding tissue was found to fall by two orders of magnitude, to the background level, within similar to 35 mu m of the implanted ceramic.
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    Biocompatibility property of 100% strontium-substituted SiO2-Al2O3-P2O5- CaO-CaF2 glass ceramics over 26 weeks implantation in rabbit model: Histology and micro-Computed Tomography analysis.
    (Journal of Biomedical Materials Research Part B: Applied Biomaterials., 2014-08) Basu, B; Sabareeswaran, A; Shenoy, SJ
    One of the desired properties for any new biomaterial composition is its long-term stability in a suitable animal model and such property cannot be appropriately assessed by performing short-term implantation studies. While hydroxyapatite (HA) or bioglass coated metallic biomaterials are being investigated for in vivo biocompatibility properties, such study is not extensively being pursued for bulk glass ceramics. In view of their inherent brittle nature, the implant stability as well as impact of long-term release of metallic ions on bone regeneration have been a major concern. In this perspective, the present article reports the results of the in vivo implantation experiments carried out using 100% strontium (Sr)-substituted glass ceramics with the nominal composition of 4.5 SiO2–3Al2O3–1.5P2O5–3SrO–2SrF2 for 26 weeks in cylindrical bone defects in rabbit model. The combination of histological and micro-computed tomography analysis provided a qualitative and quantitative understanding of the bone regeneration around the glass ceramic implants in comparison to the highly bioactive HA bioglass implants (control). The sequential polychrome labeling of bone during in vivo osseointegration using three fluorochromes followed by fluorescence microscopy observation confirmed homogeneous bone formation around the test implants. The results of the present study unequivocally confirm the long-term implant stability as well as osteoconductive property of 100% Sr-substituted glass ceramics, which is comparable to that of a known bioactive implant, that is, HA-based bioglass.
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    Biocompatibility property of 100% strontium-substituted SiO2-Al2O3-P2O5-CaO-CaF2 glass ceramics over 26 weeks implantation in rabbit model: Histology and micro-Computed Tomography analysis
    (JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS, 2015) Basu, B; Sabareeswaran, A; Shenoy, SJ
    One of the desired properties for any new biomaterial composition is its long-term stability in a suitable animal model and such property cannot be appropriately assessed by performing short-term implantation studies. While hydroxyapatite (HA) or bioglass coated metallic biomaterials are being investigated for in vivo biocompatibility properties, such study is not extensively being pursued for bulk glass ceramics. In view of their inherent brittle nature, the implant stability as well as impact of long-term release of metallic ions on bone regeneration have been a major concern. In this perspective, the present article reports the results of the in vivo implantation experiments carried out using 100% strontium (Sr)-substituted glass ceramics with the nominal composition of 4.5 SiO2-3Al(2)O(3)-1.5P(2)O(5)-3SrO-2SrF(2) for 26 weeks in cylindrical bone defects in rabbit model. The combination of histological and micro-computed tomography analysis provided a qualitative and quantitative understanding of the bone regeneration around the glass ceramic implants in comparison to the highly bioactive HA bioglass implants (control). The sequential polychrome labeling of bone during in vivo osseointegration using three fluorochromes followed by fluorescence microscopy observation confirmed homogeneous bone formation around the test implants. The results of the present study unequivocally confirm the long-term implant stability as well as osteoconductive property of 100% Sr-substituted glass ceramics, which is comparable to that of a known bioactive implant, that is, HA-based bioglass. (c) 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1168-1179, 2015.
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    Contact Guidance Mediated by Hybrid Thread Topography Enhances Osseointegration of As-machined Ti6Al4V Dental Implant.
    (Regenerative Engineering and Translational Medicine, 2023-03) Mishra, D; Neethu, RS; Shetty, V; Shenoy, SJ; Komath, M; Varma, HK; Sabareeswaran, A; Basu, B
    Purpose The main objective of this study is to investigate the key role of as-machined implant design features on the osseointegration. The bone regeneration ability of the newly developed Ti6Al4V hybrid threaded tapered implant without any surface modification has been validated and benchmarked against Straumann® implant (control) in the rabbit model for 12 weeks. Material and Methods The test and control implants were implanted in the femur medial condyle of twelve adult New Zealand white rabbits on the contralateral limbs; each femoral medial condyle received a test or control implant randomly. The bone formation and osseointegration around the implants were assessed qualitatively and quantitatively using histology, micro-computed tomography (Micro-CT), molecular gene studies, and histomorphometric analysis after 12 weeks of implantation. Results The overall assessment suggests homogenous and continuous neobone formation and osseointegration around the hybrid threads of the test implants. Superior bone-to-implant contact percentage (BIC) was observed in the case of hybrid threaded test implants with an average value of 80.8%, compared to 67.1% for the control implant. Upregulated expression of osteogenic (COL1A1, RUNX2, SPARC, and SPP1) and angiogenic (VEGF) genes in the case of test implant indicates better coupled osseointegrationa and angiogenesis. Conclusion It can be concluded that the extent of neobone formation and expression of the osteogenic/angiogenic genes is positively correlated with optimal design features of the implant, which leads to the contact guidance of the osteoblasts on the implant surface. The study also advocates that the novel tapered multithreaded implant design concept alone, without any surface modification, can facilitate osseointegration in a manner better than clinically used surface-modified implants. Lay Summary Dental implants are artificial tooth roots and are used to treat complete or partial toothlessness. The new implant design concept reported here is expected to support both soft tissue and hard tissue attachment and to improve primary stability. This study unraveled the effect of the novel external hybrid thread design on the implant integration with the surrounding bone. This aspect was validated in the rabbit model and benchmarked against the commercially available Straumann® implant. This study has unambiguously demonstrated the ability of as-machined Ti implants to facilitate better new bone and new blood vessels formation than the commercial implant.
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    In Vivo Response of Novel Calcium Phosphate-Mullite Composites: Results Up to 12 Weeks of Implantation
    (JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS, 2009) Nath, S; Basu, B; Mohanty, M; Mohanan, PV
    In this paper, the in vivo response, in particular, the histocompatibility of newly developed CaP-mullite composites is reported. In the present experiments, the bioceramic implants were inserted in the long bones of healthy rabbits according to standard protocols (ISO-10993) and the tissue response was studied at different time intervals of up to 12 weeks. Ultra high-molecular weight polyethylene (UHMWPE) was used as control samples. The postimplant bone-material interfaces were analyzed by staining of histological sections, following bone tissue histopathology protocols. The interface zones were critically observed by fluorescent optical microscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). Importantly, no inflammation, necrosis was observed during this tenure. New bone formation was observed at all the implantation time intervals (1-12 weeks). However, the bone integrity with the material was increased after 12 weeks of implantation. Although macrophages and fibrous tissue were present during the first week of implantation, they were not observed on histology sections after 12 weeks postimplantation. More importantly, foci of chondrocytes could be observed after 12 weeks of implantation. Remodeling of Haversian canal was observed at the interfacial area of natural bone and implant material. All the observations were assessed critically to analyze the in vivo biocompatibility of this novel composite material. (C) 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 90B: 547-557, 2009