In the present study composites based on polylactide and hydroxyapatite with the content of components 50:50 and 75:25 were investigated. Components were mixed at 40°C, which was followed by the sonication procedures and its precipitation in ethanol. The analysis of the following composite materials revealed that their chemicalcrystallographic characteristics of individual components remained intact after varying its dispersion and material crystallinity degree. Composite material of the ratio 75:25 were characterized by the lowest degree of crystallinity - 20.5% and the average crystallite size up to 28.8 nm showed an increased roughness and dispersive component of surface energy. In comparison to polylactide, the composite has a high capacity for osseointegration. In the paper, special attention is given to the immunomodulatory properties of composite materials. Assessment of the immune system cells showed that the macrophages are most viable in the presence of pure polylactide and composite 75/25. Intensive secretion of proinflammatory cytokines in macrophage cultures in vitro was not found at that.
This work aims to synthesize chitosan from locally available cowry and crab shells for Pharmaceutical application in drug delivery. Chitosan was synthesized from both shells using standard deacetylation technique. The synthesized chitosan, piroxicam and lactose were employed in preparing the drug loaded tablets by direct compression technique and subjected to characterization with the aid of Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Spectroscopy (SEM) and optical microscopy. Finally, the drug release rate was investigated with in vitro drug dissolution test. The results of FTIR spectra confirmed that the biopolymer extract was chitosan and it also shows that there was no interaction between chitosan and the piroxicam. The morphological properties of the samples were found to be suitable for drug delivery. The applied load and composition of tablets influenced the drug release rates.
Binder-jet 3D printing responses of sea-shell powder based ceramic composites have been evaluated considering the material consolidation mechanisms and mechanical characterisations. Initial experimental printing trials are done manually, varying the composition of the composite powders from 5% to 50% of the seashell powder and the rest plaster. Overall, the seashell and plaster combinations worked well in terms of achieving the necessary green strengths within the binder-jet process conditions. Scanning electron microscopy and 3-point bending results indicated no significant loss of properties at lower levels of the seashell component, but the strength decreased beyond the 25% mark. The optimum levels of seashell powder are found to be within 15-20% by weight in terms of the best compression strengths. Neat sea-shell powder however goes too sticky immediately after the interaction with the binder liquid and does not show evidence of any binding mechanism that can be accelerated.
The treatment of complicated crown-root fractures of tooth is often compromised by a fracture apical to the gingival margin and/or bone. This makes isolation difficult and compromises the adhesive union which is critical for a successful treatment. In the present case, the fracture line extended from cervical third of labial surface to cervical third of palatal surface sub gingivally which made the case a complicated crown root fracture. The reattachment of fragments would bring the vulnerable joint in the primary stress bearing area and in the subgingival region. Hence the tooth was removed traumatically with the help of periotome and intentional replantation was done which facilitated the attachment of fragments extra orally. Fragments reattachment was reinforced with the intraradicular fiber post and glass ionomer cement. Then the tooth was rotated 1800 to bring the subgingival fracture line to the labial surface where the occlusal load is less. As the amount of extra oral time is a critical factor in the success of reimplantation, the procedure was completed in 20 minutes. The teeth were stabilized with semi rigid splint for 6 weeks. Later full veneer crown was cemented on the tooth. The patient was followed up with clinical examination for mobility test, gingival sulcus depth and radiographic analysis to analyze the integrity of root, the alveolar cortex and the periodontal space for 12 months. The treatment is successful so far and has rendered satisfaction to both the clinician and patient.
Hip fracture in frail people is an increasing problem with a major socio-economic impact. Besides, a first hip fracture is often followed by a second fracture of the opposite hip in the following years. The authors report on four cases with extra-capsular hip fractures treated not, only for the fracture but also to avoid future contralateral fracture by implanting an innovative device as a preventive measurement.
Successful application of 1:1 layered phyllosilicates as excipients of drugs and agrochemicals depends on the efficiency and effectiveness of activation reactions carried out prior to their usage. Reluctance of kaolinite to direct reactions involving interlayer spaces created a challenge which requires a sustainable search for optimum activation agents. This study investigated the features of cyclone based wet beneficiated kaolinite with kaolinite sheets activated using solid dispersion of NaCl. Starting materials and the resulting activated counterparts were characterized for their chemistry, functionalities (as per mineral phases present), and variation of crystal sizes upon each treatment cycle along with lattice contraction and expansion in the interlayer spaces and orientation of layers (as per their morphological changes) as well as molecular vibration. It was observed that, upon successful activation with NaCl, there was a significant change in the orientation of kaolinite sheets from euhedral pseudohexagonal platelets into vermiform whose pattern offer a maximum orientation for reactions involving interlayer spaces. The formation of vermiform which may be due to packing of nano-layers was noted to be associated with the contraction of interlayer spaces of about 0.018 nm from 2θ = 12.543o to 12.552o as revealed in the x-ray diffraction trials. Therefore, the ability of NaCl activation reactions to orient kaolinite layers into well-ordered vermiform pattern makes NaCl a suitable activation agent for use when kaolinite is to be used for design of excipients for drugs and agrochemicals.
As a third-generation biomaterial, the bioactive glass (BG) has gained the attention of various research groups who have started to employ it for enhancing tissue regeneration. Most of these applications focus on bone tissue engineering based on either BG alone or BG-based composites, where the properties of the other components can improve those of the BG. Moreover, recently, the BG has become one of the important materials with ability to improve the regeneration of soft tissues. This review highlights the up-to-date advances in the different BG-based composites which have been studied in the treatment of various soft tissue injuries. These include the neuronal, muscle, lung and cardiac tissue regeneration, as well as cornea treatment. In addition, the enhancement in tissue repair due to the composite structure is discussed with comparing to the individual component structures.
Nanotechnology implies to the manipulation, reduction and fabrication of materials at nano scale. Nanoparticles, exhibiting distinct morphological characteristics which is quite different from their bulk form. In recent years nanoparticles have been produced by industries for commercial application having many benefits. Biosynthesis of nanoparticles attracts many researchers and industries to explore microorganisms such as Bacteria, Fungi, Algae etc as the perfect biological system for the assembly of different nanoparticles. Fungi being the most suitable as mycosynthesis is not only ecofriendly but also makes the downstream processing for product recovery much easier.
It’s been over 25 years since Professor Larry Hench published his seminal article entitled “Bioceramics: From Concept to Clinic”[1] and more than 40 years since he first reported the peculiar bioactive properties of glass compositions within the Na2O-CaO-P2O5-SiO2 quaternary system [2]. Curiously, the investigative ideas which led him to develop Bioglass® did not have their origin in the laboratory. They were born from the clinical need to heal the horrible wounds incurred by servicemen returning from the Vietnam War. Indeed, after a conversation with a ranking army officer, his work began under a simple hypothesis:
Bone tissue engineering, using a synthetic porous scaffold material provides some distinct advantages over autografting and allografting, and it is a rapidly growing alternative approach to heal damaged bone tissue. The current study focuses on fabrication and characterization of nano β-TCP incorporated gelatin- chitosan based composite scaffold for bone regeneration at the sites of musculoskeletal defects and disorders. Gelatin-chitosan scaffold reinforced with beta-tricalcium phosphate (β-TCP) nanopowder was fabricated through freeze drying of material’s suspension. From powder X-ray diffraction and Fourier transform infrared spectrometer analysis the presence of phase pure β-TCP powders in gelatin-chitosan matrix was confirmed. Gelatin-Chitosan-β- TCP (GCT) scaffold exhibited a homogenouos porous structure with an average pore size of 118 ± 11 μm. Micro-CT image confirmed interconnected porous network with homogeneous distribution of β-TCP nanoparticles in Gelatin- Chitosan (GC) matrix. GCT scaffold showed higher compressive strength of 2.45 ± 0.15 MPa as compared to 1 MPa exhibited by neat GC scaffold. Protein adsorption capacity was increased to 22 mg/cc in GCT scaffold from 13 mg/ cc in GC scaffold. Weight loss of GCT scaffold was lower of 26% as compared to 47% in GC scaffold after 8 weeks of incubation in phosphate buffer solution of pH 7.4. Mesenchymal stem cells cultured onto GCT scaffold exhibited higher degree of lamellipodia and filopodia extensions and greater spreading onto GCT scaffold as compared to that in GC scaffold after 7 and 14 days of culture. MTT assay suggested higher degree of proliferation of MSCs cultured onto GCT scaffold as compared to that onto pure GC scaffolds. This study demonstrates that β-TCP incorporation into gelatin- chitosan matrix improved osteogenic potential of the scaffold suitable for bone tissue engineering
In today’s world, where faster development of a new drug is crucial, not just for the patients but also for the pharmaceutical companies that are always in a competition for delivering a “new chemical entity (NCE)” to the market and the public. Bioinformatics, through various databases, web services, software and tools, has made a huge impact on the drug development process.
Some phosphate glasses containing different amounts of by-pass cement dust (BCD) were prepared by the melt quenching method. The selected molecular composition was [(100-x)% - P2O5 (x)% BCD (where 30≤ x≥60)]. The obtained experimental density and molar volume values were inspected and were then compared with those obtained empirically for the close packed structure of the corresponding compounds. The comparison between experimental and emperical values evidenced the short range order of the studied samples. The electric and dielectric properties were thoroughly investigated. The appearance of maxima and minima in the total conductivity BCD concentration dependence can be attributed to the mixed alkali – alkaline earth effect (MAAE) and to the presence of considerable amount of CaO. The suitability of such glasses to act as gamma-ray shielding materials was thoroughly investigated, and correlation between the chemical composition (the BCD concentration) and gamma-ray attenuation behavior was established.
The antimicrobial effect of staphylococcus aureus, Streptococcus mutans, E. coli and Candida albicans are dependent on surface properties and restorative dental materials types. The aim of this study was to evaluate the effect of antibiotics on the residual natural saliva (after Filtek, glass-ionomer, porcelain and zirconia takeout from it). Also, the effect of brushing on fungi and bacteria growth in these surface materials was characterized. The results show that, bacterial growth around Filtek, glass ionomer, porcelain, and zirconia materials after takeout from saliva that is meant these materials have no resistance for E. coli, staphylococcus aureus, Streptococcus mutans and Candida albicans. The color of residual saliva changed. All antibiotics caused inhabitation zone except Ampicillin. Ciprofloxacin shows significant inhibition zone for all used materials. Also, brushing removed most if not all fungi and bacteria formed on surface dental materials.
As a relatively new biomaterial, silicon nitride (Si3N4) is currently used as an arthrodesis device in the cervical and thoracolumbar spine, and it is under consideration as a bearing material in total joint arthroplasty. In this paper, the development and validation of the manufacturing processes used in the production of Si3N4 biomedical implants are presented and discussed. Manufacturing was conducted in a facility specifically dedicated for this purpose using processes designed to yield net shape intervertebral spinal spacers by conventional dry-pressing, CNC machining of components in the green state, sintering, and hot isostatic pressing. These manufacturing methods were industrialized using Taguchi fractional factorial experimental designs, followed by implementation of statistical process controls. The roles of various processing parameters including raw materials, pressing, and firing conditions (i.e., time, temperature, and pressure) are elucidated. For these devices, it was demonstrated that acceptable physical, mechanical, and dimensional properties were consistently obtained from carefully designed and statistically controlled processes.
