someswar datta - Academia.edu (original) (raw)

Papers by someswar datta

Research paper thumbnail of CSIR-CGCRI: Current nano activities in the area of glass and ceramics materials

Research paper thumbnail of Novel Ceramics and Glass-Ceramics by Microwave and Conventional Processing: A Review

Current Trends on Glass and Ceramic Materials, 2013

Research paper thumbnail of Colloidal bismuth as nucleation catalyst for preparing magnetic glass-ceramics

Journal of Materials Science Letters, 1984

Research paper thumbnail of Synthesis and characterisation of free standing, one­dimensional, Al–SiC based functionally gradient material

Materials Science and Technology

Freestanding polycrystalline diamond (PCD) coatings are of immense technological importance. PCD ... more Freestanding polycrystalline diamond (PCD) coatings are of immense technological importance. PCD has been grown over silicon substrates by microwave plasma assisted chemical vapor deposition (MWPACVD) process. The coatings are grown by suitable optimisation of the growth parameters of a 915 MHz microwave reactor. Thereafter, 1:1:1 solution of hydrofluoric acid (HF), nitric acid (HNO 3) and acetic acid (CH 3 COOH) is used to etch out the silicon wafer from the backside of the coating. Hereby, freshly generated nucleation surface, could be characterised by scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy and stylus profilometer and could be compared with the growth side. It is found that both the nucleation side and growth side are of very high quality (full width at half maxima, i.e., FWHM < 8 cm-1). The growth side is (111) textured, whereas, the nucleation side is very smooth with embedded detonation-nano-diamond (DND) agglomerates. These freestanding coatings are successfully laser cut into different geometrical shapes. They are found to be optically translucent having high refractive index. Cross-sectional microscopy of the laser cut edge reveals novel melting features of the CVD grown diamond columns.

Research paper thumbnail of Oxidation protection of gamma-titanium aluminide using glass–ceramic coatings

Surface and Coatings Technology

Research paper thumbnail of Microwave Sintering of Titania

Transactions of the Indian Ceramic Society

Research paper thumbnail of A novel, multi-barrier, drug eluting calcium sulfate/biphasic calcium phosphate biodegradable composite bone cement for treatment of experimental MRSA osteomyelitis in rabbit model

Journal of controlled release : official journal of the Controlled Release Society, Jan 10, 2016

This article discloses the development of an effective and versatile technology to prepare a nove... more This article discloses the development of an effective and versatile technology to prepare a novel antibiotics-loaded biodegradable composite bone cement to treat methicillin-resistant Staphylococcal (MRSA) osteomyelitis and reports its detail in vitro characterization, drug loading efficiency, physico-mechanical properties, drug elution in simulated body fluid (SBF) and human plasma, merits and demerits over poly-methyl methacrylate (PMMA) cement. Chronic osteomyelitis in rabbit tibia (42) was induced by MRSA and composite cement was implanted to evaluate its safety and efficacy over PMMA cement and parenteral treated animals with histopathology, radiographs, bone/plasma drugs concentration, and SEM for 90days. The composite cement showed higher setting time, degradability, pH rise, injectability, in vitro drug elution but lesser mechanical strength than PMMA cement. Antibiotics release from cement beads was faster in SBF than plasma. Further, in vivo antibiotics elution from compo...

Research paper thumbnail of Influence of single and binary doping of strontium and lithium on in vivo biological properties of bioactive glass scaffolds

Scientific Reports, 2016

Effects of strontium and lithium ion doping on the biological properties of bioactive glass (BAG)... more Effects of strontium and lithium ion doping on the biological properties of bioactive glass (BAG) porous scaffolds have been checked in vitro and in vivo. BAG scaffolds were prepared by conventional glass melting route and subsequently, scaffolds were produced by evaporation of fugitive pore formers. After thorough physico-chemical and in vitro cell characterization, scaffolds were used for pre-clinical study. Soft and hard tissue formation in a rabbit femoral defect model after 2 and 4 months, were assessed using different tools. Histological observations showed excellent osseous tissue formation in Sr and Li + Sr scaffolds and moderate bone regeneration in Li scaffolds. Fluorochrome labeling studies showed wide regions of new bone formation in Sr and Li + Sr doped samples as compared to Li doped samples. SEM revealed abundant collagenous network and minimal or no interfacial gap between bone and implant in Sr and Li + Sr doped samples compared to Li doped samples. Micro CT of Li + Sr samples showed highest degree of peripheral cancellous tissue formation on periphery and cortical tissues inside implanted samples and vascularity among four compositions. Our findings suggest that addition of Sr and/or Li alters physico-chemical properties of BAG and promotes early stage in vivo osseointegration and bone remodeling that may offer new insight in bone tissue engineering. The management of bone defects still remains a challenge for orthopedic surgeons. It has been reported that occurrence of impaired fracture healing of bone defects is nearly 5-10% 1. In United States alone, 1.3 million people undergo bone graft surgeries each year for skeletal defects resulting from either accidents or disease 2. Bone grafting, either from autografts or allografts is a well-known surgical procedure although has associated drawbacks of additional surgery, limited availability, potential risks of disease transmission, immunogenic response and long-term complications 3. To overcome these limitations, the development as well as the availability of new orthobiologic materials to aid in the management of bony defects is rising. On the other hand, tissue engineering mainly with engineered grafts is now-a-days a major thrust area toward repair and replacement of these diseased and damaged bone tissues. To achieve this goal, bioactive glasses and calcium phosphate have been investigated as bone repair scaffolds but having some limitations 4,5. Mechanical and osteoinductive properties of scaffold materials can be improved via metallic ions substitution 6. Among various ion substitutions, strontium (Sr 2+), zinc (Zn 2+), magnesium (Mg 2+) and silicon (Si 4+) have been widely studied 7-13. Sr was the only one that was correlated with an increase in bone compression strength 14. Stimulatory effect of Sr on osteoblasts and inhibitory effect on osteoclasts have been established 15-18. Further, strontium ranelate has been proven to reduce the incidence of fractures in osteoporotic elderly patients 19. Similarly, lithium (Li +) plays

Research paper thumbnail of Studies on a novel bioactive glass and composite coating with hydroxyapatite on titanium based alloys: Effect of gamma-sterilization on coating

A novel silicate based bioactive glass coating composition containing B2O3 and TiO2 having matchi... more A novel silicate based bioactive glass coating composition containing B2O3 and TiO2 having matching thermal properties with that of Ti6Al4V implants was developed and characterized. A conventional vitreous enamelling technique was used for coating small ...

Research paper thumbnail of Effect of Processing Parameters on Thermal Cycling Behavior of Al2O3-Al2O3 Brazed Joints

Metallurgical and Materials Transactions B, 2016

Research paper thumbnail of Characterization of microwave processed aluminium powder

Ceramics International, Apr 1, 2011

Commercial Al powder was exposed to microwave radiation for 45 min. The as received and microwave... more Commercial Al powder was exposed to microwave radiation for 45 min. The as received and microwave heated Al powders were characterized by X-ray diffraction analysis (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive Xray (EDX) analysis and transmission electron microscopy (TEM). XRD of the microwave treated Al powder confirmed the formation of Al-Al 2 O 3 composite. FTIR studies and EDX analysis indicated the transformation of Al powder into Al-Al 2 O 3 core-shell composite powder after microwave processing. SEM showed that the morphology of the microwave processed Al powder was quite different from that of the as-received Al powder. TEM image of the microwave treated Al powder supported the FTIR and EDX data.

Research paper thumbnail of Systematic approach to treat chronic osteomyelitis through ceftriaxone-sulbactam impregnated porous beta-tri calcium phosphate localized delivery system

ABSTRACT Present investigation deals with in vitro and in vivo experimentation to treat chronic o... more ABSTRACT Present investigation deals with in vitro and in vivo experimentation to treat chronic osteomyelitis, using pure β-tri calcium phosphate porous scaffolds. A novel approach was given to treat such infections using the scaffolds and drug combinations consisting of ideal antibiotics. In vitro studies include variation of porosity with interconnectivity, pore-drug interfacial studies by SEM-EDAX and drug elution studies both in contact with PBS and SBF at ca. 37°C. In vivo trials were based on experimental osteomyelitis in rabbit model in tibia by Staphylococcus aureus. Characterizations included histopathology, radiology and estimation of drug in both bone and serum for 42 days by HPLC and subsequent bone–biomaterial interface by SEM. Samples having 60–65% porosity with average pore size ca. 55μm and higher interconnectivity (22–113μm), high adsorption efficiency (ca. 79%) of drug showed prolonged, sustained release of the drugs considered being sufficient to treat chronic osteomyelitis with desirable bone formation.

Research paper thumbnail of Drug-eluting implants for osteomyelitis

Critical Reviews in Therapeutic Drug Carrier Systems, Feb 1, 2007

Osteomyelitis, an inflammatory process accompanied by bone destruction, is caused by infective mi... more Osteomyelitis, an inflammatory process accompanied by bone destruction, is caused by infective microorganisms. The high success rates of antimicrobial therapy by conventional routes of administration in controlling most infectious diseases have not yet been achieved with osteomyelitis for several reasons. Local and sustained availability of drugs have proven to be more effective in achieving prophylactic and therapeutic outcomes. This review introduces osteomyelitis--its prevalence and pathogenesis, the present options for drug delivery and their limitations, and the wide range of carrier materials and effective drug choices, with major focus on the pharmaceutical concepts involved in drug delivery system design and development. With increasing numbers of orthopedic surgeries and the advent of combination devices that provide support and deliver drugs, local drug delivery for osteomyelitis is a topic of importance for both social and commercial interests.

Research paper thumbnail of Safety and efficacy of additive and subtractive surface modification of Ti6Al4V endosseous implant in goat bone

Journal of the Mechanical Behavior of Biomedical Materials, 2016

Growing interest of endosseous implant research is focused on surface modification to achieve ear... more Growing interest of endosseous implant research is focused on surface modification to achieve early and strong osseointegration. The present study compared the behaviour of hydroxyapatite coated, zinc doped hydroxyapatite coated and hydrothermally treated titanium (Ti6Al4V) with machined Ti6Al4V implants (control) on osseointegration. The surface characterization and bacterial affinity test for implants were performed. Forty eight (48) cylinders (4 types in each animal) were placed in the humerus bone of 12 black Bengal goats. Bone-implant interface was examined with histological, radiological parameters and scanning electron microscopy on 42nd, 90th, and 180th day post-implantation. Surface roughness alterations of bone-detached implants with time were analyzed by non-contact profilometer. Push-out test (90th day) was performed to assess the strength of bony integration of implants. The coated implants revealed direct and early bone-implant contact but high bacterial affinity and coating resorption/cracks. Low bacterial affinity and strongest osseointegration was observed with hydrothermally treated implants. Poor bacterial affinity and delayed but strong fixation were evident with control implant. Based on the results of laboratory and animal experiments, we conclude that the hydrothermal modification of titanium implant is the more suitable way to achieve safe and effective osseointegration than the other three implant types for endosseous application.

Research paper thumbnail of High T sub c superconductor coating on metal substrates by an electrophoretic technique

Research paper thumbnail of Profilometric analysis of root surfaces after using various polishing agents

Journal of Indian Society of Periodontology, 2015

Polishing is an important step in oral prophylaxis procedure which retards further accumulation o... more Polishing is an important step in oral prophylaxis procedure which retards further accumulation of plaque on the root surfaces. Though polishing was done with various abrasive particles with different sizes over a long period of time, it was never been highlighted to evaluate the ideal polishing material and the particle size that would produce the ideal surface smoothness (Ra &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.2 μm). The present study was carried out on 70 periodontally involved, caries-free extracted human teeth from 42 patients. All the teeth were collected from the region of incisors, canines, and premolars. In vitro scaling and root planing were performed by piezoelectric scaler and Gracey&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s area specific curettes, respectively. All the teeth were grouped at random into control and experimental. The collections of abrasive materials were done directly from the market, and the different particle sizes were prepared in the laboratory. The polishing was done at a constant speed of 200 rpm with cylindrical nylon bristle brush followed by rubber prophy cup. Each group belonging to control and experimental was subjected to profilometric study for evaluation of surface roughness. Regular polishing abrasives are not able to produce the surface smoothness of our desire level (i.e., Ra &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.2 μm), which can be achieved only by submicron-sized particles. Regular size polishing particles available in the market (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;5 μm) are not able to produce the surface smoothness &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.2 μm. Only, submicron sized particles are able to produce the desired smoothness.

Research paper thumbnail of Influence of growth conditions on microstructure and defects in diamond coatings grown by microwave plasma enhanced CVD

Bulletin of Materials Science, 2015

Diamond coatings were grown on SiO 2 /Si substrate under various process conditions by microwave ... more Diamond coatings were grown on SiO 2 /Si substrate under various process conditions by microwave plasma chemical vapour deposition (MPCVD) using CH 4 /H 2 gas mixture. In this paper, we present a microstructural study to elucidate on the growth mechanism and evolution of defects, viz., strain, dislocations, stacking faults, twins and non-diamond impurities in diamond coatings grown under different process conditions. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy were used to characterize the diamond coatings. It has been shown that our new approach of prolonged substrate pre-treatment under hydrogen plasma yielded a new growth sequence that the SiO 2 layer on the Si substrate was first reduced to yield Si layer of ∼150 nm thickness before diamond was allowed to grow under CH 4-H 2 plasma, created subsequently. It has also been shown that Si and O as impurity from the substrate hinders the initial diamond growth to yield non-diamond phases. It is being suggested that the crystal defects like twins, stacking faults, dislocations in the diamond grains and dislocations in the intermediate Si layer are generated due to the development of non-uniform stresses during diamond growth at high temperature.

Research paper thumbnail of Microscopic properties of MPCVD diamond coatings studied by micro-Raman and micro-photoluminescence spectroscopy

Bulletin of Materials Science, 2015

Diamond coatings were deposited on silicon (100) substrate using the microwave plasma chemical va... more Diamond coatings were deposited on silicon (100) substrate using the microwave plasma chemical vapour deposition (MPCVD) technique at different process conditions. Process parameters such as CH 4-H 2 gas mixture concentration, microwave power, chamber pressure and substrate temperature were varied. The diamond coatings were characterized by micro-Raman and micro-photoluminescence (PL) spectroscopy techniques. In this paper we report a comparison of the overall quality of MPCVD polycrystalline diamond coatings grown under different processing conditions in terms of stress distribution, thickness uniformity and surface roughness. Micro-Raman spectroscopy studies over various points on the deposited coating showed that the Raman line widths of diamond peak varied from 3.2 to 18.3 cm −1 with the variation of CH 4 and H 2 gas concentration. The micro-PL spectra suggested the presence of impurity concentration and defects within the diamond coating synthesized at different processing conditions. Transmission electron microscopy (TEM) images provide the direct evidence of the presence of crystal defects which corroborates the Raman and PL results. The coherence scanning interferometry (CSI) showed that surface roughness of diamond coating varied from 0.43 to 11 µm with thickness at different positions of the three coating samples. It has been concluded that Raman line-width broadening and Raman-shift are due to the presence of crystal defects as well as non-uniform distribution of stresses present in the diamond crystals of the coating, due to the incorporation of Si as impurity element and non-uniform temperature distribution during growth. Defect density gets reduced at higher processing temperatures. It is also being proposed that better thickness uniformity and lower surface roughness can be achieved for coatings deposited at low methane concentration under optimized process conditions.

Research paper thumbnail of Articulating Biomaterials

Processing Techniques and Tribological Behavior of Composite Materials, 2015

Research paper thumbnail of Development and Applications of Varieties of Bioactive Glass Compositions in Dental Surgery, Third Generation Tissue Engineering, Orthopaedic Surgery and as Drug Delivery System

Biomaterials Applications for Nanomedicine, 2011

Biomaterials Applications for Nanomedicine 70 neck (e.g., mandible replacement); however, such im... more Biomaterials Applications for Nanomedicine 70 neck (e.g., mandible replacement); however, such implants cannot be easily contoured in the operating room, and screws cannot be easily placed into bioactive glass blocks because they defy drilling and have a tendency to fragment during creation of screw holes. 2. Bioactive glass materials Legendary Prof. L. L. Hench of University of Florida, USA discovered in 1969 that some compositions of glasses can bond chemically with bone when implanted to living tissues. Many researchers later on discovered some other ceramics, glass-ceramics and composites also have the same property (

Research paper thumbnail of CSIR-CGCRI: Current nano activities in the area of glass and ceramics materials

Research paper thumbnail of Novel Ceramics and Glass-Ceramics by Microwave and Conventional Processing: A Review

Current Trends on Glass and Ceramic Materials, 2013

Research paper thumbnail of Colloidal bismuth as nucleation catalyst for preparing magnetic glass-ceramics

Journal of Materials Science Letters, 1984

Research paper thumbnail of Synthesis and characterisation of free standing, one­dimensional, Al–SiC based functionally gradient material

Materials Science and Technology

Freestanding polycrystalline diamond (PCD) coatings are of immense technological importance. PCD ... more Freestanding polycrystalline diamond (PCD) coatings are of immense technological importance. PCD has been grown over silicon substrates by microwave plasma assisted chemical vapor deposition (MWPACVD) process. The coatings are grown by suitable optimisation of the growth parameters of a 915 MHz microwave reactor. Thereafter, 1:1:1 solution of hydrofluoric acid (HF), nitric acid (HNO 3) and acetic acid (CH 3 COOH) is used to etch out the silicon wafer from the backside of the coating. Hereby, freshly generated nucleation surface, could be characterised by scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy and stylus profilometer and could be compared with the growth side. It is found that both the nucleation side and growth side are of very high quality (full width at half maxima, i.e., FWHM < 8 cm-1). The growth side is (111) textured, whereas, the nucleation side is very smooth with embedded detonation-nano-diamond (DND) agglomerates. These freestanding coatings are successfully laser cut into different geometrical shapes. They are found to be optically translucent having high refractive index. Cross-sectional microscopy of the laser cut edge reveals novel melting features of the CVD grown diamond columns.

Research paper thumbnail of Oxidation protection of gamma-titanium aluminide using glass–ceramic coatings

Surface and Coatings Technology

Research paper thumbnail of Microwave Sintering of Titania

Transactions of the Indian Ceramic Society

Research paper thumbnail of A novel, multi-barrier, drug eluting calcium sulfate/biphasic calcium phosphate biodegradable composite bone cement for treatment of experimental MRSA osteomyelitis in rabbit model

Journal of controlled release : official journal of the Controlled Release Society, Jan 10, 2016

This article discloses the development of an effective and versatile technology to prepare a nove... more This article discloses the development of an effective and versatile technology to prepare a novel antibiotics-loaded biodegradable composite bone cement to treat methicillin-resistant Staphylococcal (MRSA) osteomyelitis and reports its detail in vitro characterization, drug loading efficiency, physico-mechanical properties, drug elution in simulated body fluid (SBF) and human plasma, merits and demerits over poly-methyl methacrylate (PMMA) cement. Chronic osteomyelitis in rabbit tibia (42) was induced by MRSA and composite cement was implanted to evaluate its safety and efficacy over PMMA cement and parenteral treated animals with histopathology, radiographs, bone/plasma drugs concentration, and SEM for 90days. The composite cement showed higher setting time, degradability, pH rise, injectability, in vitro drug elution but lesser mechanical strength than PMMA cement. Antibiotics release from cement beads was faster in SBF than plasma. Further, in vivo antibiotics elution from compo...

Research paper thumbnail of Influence of single and binary doping of strontium and lithium on in vivo biological properties of bioactive glass scaffolds

Scientific Reports, 2016

Effects of strontium and lithium ion doping on the biological properties of bioactive glass (BAG)... more Effects of strontium and lithium ion doping on the biological properties of bioactive glass (BAG) porous scaffolds have been checked in vitro and in vivo. BAG scaffolds were prepared by conventional glass melting route and subsequently, scaffolds were produced by evaporation of fugitive pore formers. After thorough physico-chemical and in vitro cell characterization, scaffolds were used for pre-clinical study. Soft and hard tissue formation in a rabbit femoral defect model after 2 and 4 months, were assessed using different tools. Histological observations showed excellent osseous tissue formation in Sr and Li + Sr scaffolds and moderate bone regeneration in Li scaffolds. Fluorochrome labeling studies showed wide regions of new bone formation in Sr and Li + Sr doped samples as compared to Li doped samples. SEM revealed abundant collagenous network and minimal or no interfacial gap between bone and implant in Sr and Li + Sr doped samples compared to Li doped samples. Micro CT of Li + Sr samples showed highest degree of peripheral cancellous tissue formation on periphery and cortical tissues inside implanted samples and vascularity among four compositions. Our findings suggest that addition of Sr and/or Li alters physico-chemical properties of BAG and promotes early stage in vivo osseointegration and bone remodeling that may offer new insight in bone tissue engineering. The management of bone defects still remains a challenge for orthopedic surgeons. It has been reported that occurrence of impaired fracture healing of bone defects is nearly 5-10% 1. In United States alone, 1.3 million people undergo bone graft surgeries each year for skeletal defects resulting from either accidents or disease 2. Bone grafting, either from autografts or allografts is a well-known surgical procedure although has associated drawbacks of additional surgery, limited availability, potential risks of disease transmission, immunogenic response and long-term complications 3. To overcome these limitations, the development as well as the availability of new orthobiologic materials to aid in the management of bony defects is rising. On the other hand, tissue engineering mainly with engineered grafts is now-a-days a major thrust area toward repair and replacement of these diseased and damaged bone tissues. To achieve this goal, bioactive glasses and calcium phosphate have been investigated as bone repair scaffolds but having some limitations 4,5. Mechanical and osteoinductive properties of scaffold materials can be improved via metallic ions substitution 6. Among various ion substitutions, strontium (Sr 2+), zinc (Zn 2+), magnesium (Mg 2+) and silicon (Si 4+) have been widely studied 7-13. Sr was the only one that was correlated with an increase in bone compression strength 14. Stimulatory effect of Sr on osteoblasts and inhibitory effect on osteoclasts have been established 15-18. Further, strontium ranelate has been proven to reduce the incidence of fractures in osteoporotic elderly patients 19. Similarly, lithium (Li +) plays

Research paper thumbnail of Studies on a novel bioactive glass and composite coating with hydroxyapatite on titanium based alloys: Effect of gamma-sterilization on coating

A novel silicate based bioactive glass coating composition containing B2O3 and TiO2 having matchi... more A novel silicate based bioactive glass coating composition containing B2O3 and TiO2 having matching thermal properties with that of Ti6Al4V implants was developed and characterized. A conventional vitreous enamelling technique was used for coating small ...

Research paper thumbnail of Effect of Processing Parameters on Thermal Cycling Behavior of Al2O3-Al2O3 Brazed Joints

Metallurgical and Materials Transactions B, 2016

Research paper thumbnail of Characterization of microwave processed aluminium powder

Ceramics International, Apr 1, 2011

Commercial Al powder was exposed to microwave radiation for 45 min. The as received and microwave... more Commercial Al powder was exposed to microwave radiation for 45 min. The as received and microwave heated Al powders were characterized by X-ray diffraction analysis (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive Xray (EDX) analysis and transmission electron microscopy (TEM). XRD of the microwave treated Al powder confirmed the formation of Al-Al 2 O 3 composite. FTIR studies and EDX analysis indicated the transformation of Al powder into Al-Al 2 O 3 core-shell composite powder after microwave processing. SEM showed that the morphology of the microwave processed Al powder was quite different from that of the as-received Al powder. TEM image of the microwave treated Al powder supported the FTIR and EDX data.

Research paper thumbnail of Systematic approach to treat chronic osteomyelitis through ceftriaxone-sulbactam impregnated porous beta-tri calcium phosphate localized delivery system

ABSTRACT Present investigation deals with in vitro and in vivo experimentation to treat chronic o... more ABSTRACT Present investigation deals with in vitro and in vivo experimentation to treat chronic osteomyelitis, using pure β-tri calcium phosphate porous scaffolds. A novel approach was given to treat such infections using the scaffolds and drug combinations consisting of ideal antibiotics. In vitro studies include variation of porosity with interconnectivity, pore-drug interfacial studies by SEM-EDAX and drug elution studies both in contact with PBS and SBF at ca. 37°C. In vivo trials were based on experimental osteomyelitis in rabbit model in tibia by Staphylococcus aureus. Characterizations included histopathology, radiology and estimation of drug in both bone and serum for 42 days by HPLC and subsequent bone–biomaterial interface by SEM. Samples having 60–65% porosity with average pore size ca. 55μm and higher interconnectivity (22–113μm), high adsorption efficiency (ca. 79%) of drug showed prolonged, sustained release of the drugs considered being sufficient to treat chronic osteomyelitis with desirable bone formation.

Research paper thumbnail of Drug-eluting implants for osteomyelitis

Critical Reviews in Therapeutic Drug Carrier Systems, Feb 1, 2007

Osteomyelitis, an inflammatory process accompanied by bone destruction, is caused by infective mi... more Osteomyelitis, an inflammatory process accompanied by bone destruction, is caused by infective microorganisms. The high success rates of antimicrobial therapy by conventional routes of administration in controlling most infectious diseases have not yet been achieved with osteomyelitis for several reasons. Local and sustained availability of drugs have proven to be more effective in achieving prophylactic and therapeutic outcomes. This review introduces osteomyelitis--its prevalence and pathogenesis, the present options for drug delivery and their limitations, and the wide range of carrier materials and effective drug choices, with major focus on the pharmaceutical concepts involved in drug delivery system design and development. With increasing numbers of orthopedic surgeries and the advent of combination devices that provide support and deliver drugs, local drug delivery for osteomyelitis is a topic of importance for both social and commercial interests.

Research paper thumbnail of Safety and efficacy of additive and subtractive surface modification of Ti6Al4V endosseous implant in goat bone

Journal of the Mechanical Behavior of Biomedical Materials, 2016

Growing interest of endosseous implant research is focused on surface modification to achieve ear... more Growing interest of endosseous implant research is focused on surface modification to achieve early and strong osseointegration. The present study compared the behaviour of hydroxyapatite coated, zinc doped hydroxyapatite coated and hydrothermally treated titanium (Ti6Al4V) with machined Ti6Al4V implants (control) on osseointegration. The surface characterization and bacterial affinity test for implants were performed. Forty eight (48) cylinders (4 types in each animal) were placed in the humerus bone of 12 black Bengal goats. Bone-implant interface was examined with histological, radiological parameters and scanning electron microscopy on 42nd, 90th, and 180th day post-implantation. Surface roughness alterations of bone-detached implants with time were analyzed by non-contact profilometer. Push-out test (90th day) was performed to assess the strength of bony integration of implants. The coated implants revealed direct and early bone-implant contact but high bacterial affinity and coating resorption/cracks. Low bacterial affinity and strongest osseointegration was observed with hydrothermally treated implants. Poor bacterial affinity and delayed but strong fixation were evident with control implant. Based on the results of laboratory and animal experiments, we conclude that the hydrothermal modification of titanium implant is the more suitable way to achieve safe and effective osseointegration than the other three implant types for endosseous application.

Research paper thumbnail of High T sub c superconductor coating on metal substrates by an electrophoretic technique

Research paper thumbnail of Profilometric analysis of root surfaces after using various polishing agents

Journal of Indian Society of Periodontology, 2015

Polishing is an important step in oral prophylaxis procedure which retards further accumulation o... more Polishing is an important step in oral prophylaxis procedure which retards further accumulation of plaque on the root surfaces. Though polishing was done with various abrasive particles with different sizes over a long period of time, it was never been highlighted to evaluate the ideal polishing material and the particle size that would produce the ideal surface smoothness (Ra &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.2 μm). The present study was carried out on 70 periodontally involved, caries-free extracted human teeth from 42 patients. All the teeth were collected from the region of incisors, canines, and premolars. In vitro scaling and root planing were performed by piezoelectric scaler and Gracey&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s area specific curettes, respectively. All the teeth were grouped at random into control and experimental. The collections of abrasive materials were done directly from the market, and the different particle sizes were prepared in the laboratory. The polishing was done at a constant speed of 200 rpm with cylindrical nylon bristle brush followed by rubber prophy cup. Each group belonging to control and experimental was subjected to profilometric study for evaluation of surface roughness. Regular polishing abrasives are not able to produce the surface smoothness of our desire level (i.e., Ra &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.2 μm), which can be achieved only by submicron-sized particles. Regular size polishing particles available in the market (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;5 μm) are not able to produce the surface smoothness &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.2 μm. Only, submicron sized particles are able to produce the desired smoothness.

Research paper thumbnail of Influence of growth conditions on microstructure and defects in diamond coatings grown by microwave plasma enhanced CVD

Bulletin of Materials Science, 2015

Diamond coatings were grown on SiO 2 /Si substrate under various process conditions by microwave ... more Diamond coatings were grown on SiO 2 /Si substrate under various process conditions by microwave plasma chemical vapour deposition (MPCVD) using CH 4 /H 2 gas mixture. In this paper, we present a microstructural study to elucidate on the growth mechanism and evolution of defects, viz., strain, dislocations, stacking faults, twins and non-diamond impurities in diamond coatings grown under different process conditions. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy were used to characterize the diamond coatings. It has been shown that our new approach of prolonged substrate pre-treatment under hydrogen plasma yielded a new growth sequence that the SiO 2 layer on the Si substrate was first reduced to yield Si layer of ∼150 nm thickness before diamond was allowed to grow under CH 4-H 2 plasma, created subsequently. It has also been shown that Si and O as impurity from the substrate hinders the initial diamond growth to yield non-diamond phases. It is being suggested that the crystal defects like twins, stacking faults, dislocations in the diamond grains and dislocations in the intermediate Si layer are generated due to the development of non-uniform stresses during diamond growth at high temperature.

Research paper thumbnail of Microscopic properties of MPCVD diamond coatings studied by micro-Raman and micro-photoluminescence spectroscopy

Bulletin of Materials Science, 2015

Diamond coatings were deposited on silicon (100) substrate using the microwave plasma chemical va... more Diamond coatings were deposited on silicon (100) substrate using the microwave plasma chemical vapour deposition (MPCVD) technique at different process conditions. Process parameters such as CH 4-H 2 gas mixture concentration, microwave power, chamber pressure and substrate temperature were varied. The diamond coatings were characterized by micro-Raman and micro-photoluminescence (PL) spectroscopy techniques. In this paper we report a comparison of the overall quality of MPCVD polycrystalline diamond coatings grown under different processing conditions in terms of stress distribution, thickness uniformity and surface roughness. Micro-Raman spectroscopy studies over various points on the deposited coating showed that the Raman line widths of diamond peak varied from 3.2 to 18.3 cm −1 with the variation of CH 4 and H 2 gas concentration. The micro-PL spectra suggested the presence of impurity concentration and defects within the diamond coating synthesized at different processing conditions. Transmission electron microscopy (TEM) images provide the direct evidence of the presence of crystal defects which corroborates the Raman and PL results. The coherence scanning interferometry (CSI) showed that surface roughness of diamond coating varied from 0.43 to 11 µm with thickness at different positions of the three coating samples. It has been concluded that Raman line-width broadening and Raman-shift are due to the presence of crystal defects as well as non-uniform distribution of stresses present in the diamond crystals of the coating, due to the incorporation of Si as impurity element and non-uniform temperature distribution during growth. Defect density gets reduced at higher processing temperatures. It is also being proposed that better thickness uniformity and lower surface roughness can be achieved for coatings deposited at low methane concentration under optimized process conditions.

Research paper thumbnail of Articulating Biomaterials

Processing Techniques and Tribological Behavior of Composite Materials, 2015

Research paper thumbnail of Development and Applications of Varieties of Bioactive Glass Compositions in Dental Surgery, Third Generation Tissue Engineering, Orthopaedic Surgery and as Drug Delivery System

Biomaterials Applications for Nanomedicine, 2011

Biomaterials Applications for Nanomedicine 70 neck (e.g., mandible replacement); however, such im... more Biomaterials Applications for Nanomedicine 70 neck (e.g., mandible replacement); however, such implants cannot be easily contoured in the operating room, and screws cannot be easily placed into bioactive glass blocks because they defy drilling and have a tendency to fragment during creation of screw holes. 2. Bioactive glass materials Legendary Prof. L. L. Hench of University of Florida, USA discovered in 1969 that some compositions of glasses can bond chemically with bone when implanted to living tissues. Many researchers later on discovered some other ceramics, glass-ceramics and composites also have the same property (