Nanoceramics in biomedical applications

An improved understanding of the interactions at the anoscale level between the bioceramics in medical implants and the hard or soft tissues in the human body could contribute significantly to the design of new-generation prostheses and postoperative patient management strategies. Overall the benefits of advanced ceramic materials in biomedical applications have been universally accepted, specifically in terms of their strength, biocompatibility, hydrophilicity and wear resistance in articulating joints. The continuous development of new-generation impalnts untilising nanocoatings with novel nanosensors and devices is leaf=ding to better compatibility with human tissue and improved well-being and longevity for patients. This article gives a short oevrview odf bioceramics and reexamines key issues of concern for processing and applying nanosensors as biomaterials

Innovative bioceramics

Overall, the benefits of advanced ceramic materials in biomedical applications have been universally appreciated, specifically, in terms of their strength, biocompatibility and wear resistance. However, the amount of supporting data is not large and the continuous development of new methods is pertinent for better understanding of the microstructure-properties relationship and, in general, for obtaining new directives for their further improvement. This paper gives an overview of some of the more innovative applications of bioceramics in medicine. © Institute of Materials Engineering Australasia Ltd - Materials Forum Volume 27 - Published 2004

Marine skeletons: Towards hard tissue repair and regeneration

© 2018 by the authors. Musculoskeletal disorders in the elderly have significantly increased due to the increase in an ageing population. The treatment of these diseases necessitates surgical procedures, including total joint replacements such as hip and knee joints. Over the years a number of treatment options have been specifically established which are either permanent or use temporary natural materials such as marine skeletons that possess unique architectural structure and chemical composition for the repair and regeneration of bone tissue. This review paper will give an overview of presently used materials and marine structures for hard tissue repair and regeneration, drugs of marine origin and other marine products which show potential for musculoskeletal treatment

The effect of titanium (Ti) and titanium 500 (ti 500) implantation on the activation of rat macrophage subgroups

© 2019, Editorial Ciencias Medicas. All rights reserved. Introduction: Nowadays it is necessary to make new researches in order to solve the problems related to the prolongation of life and related health problems, especially fractures and spinal degeneration. The biocompatibility, mechanical compatibility, morphological compatibility and osseointegration properties of the implant material are very important. In order to prevent unwanted side effects in the use of biomaterials, new strategies need to be developed. Implants, where they will be implanted and their functions will vary according to the characteristics of the material used. The most commonly used metallic materials are 316L stainless steel, Co-Cr alloys and Ti alloys. Objective: To demostrate the effect of Titanium and Titanium 500 on activation of macropages Material and Methods: Our research was performed in the Laboratory of Cytokines and Receptors in the Department of Physiology of Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa. Our research has been approved by the Animal Experiments Local Ethics Committee of Bezmialem Vakif University (Approval Number:2017/218). In order to control the rejection of the patient with specific inflammation caused by titanium implantation, we analyzed the first triggered cells of the innate immun system, especially macrophages and sub-groups (M1, M2a, M2b, M2c), by implanting Titanium and Titanium 500 into the spinal region in Wistar albino male rats. According to the Power Analysis statistic program, 3 different groups of Wistar albino species male rats with a weight of 250 - 300 grams and 10-12 weeks of age were formed. Group I (n: 8, Sham group (Control)), Group II (n: 8, Titanium alloy), Group III (n: 8, Titanium 500). No implant was used in Group I (sham group). Only surgical stress was applied to the rats and they were closed again. In Group II and Group III, the rods were placed on the lamina. Peripheral blood samples were collected on the 1st, 3rd, 5th and 7th days following the implantation phase. M1 macrophages (CCL3, CCL4, CXCL9, IL-23), M2a macrophages (CD163, CD206), M2b macrophages (CCL1), M2c macrophage (SLAM) markers were examined by ELISA (Enzyme-Linked ImmunoSorbent Assay) method. Groups were compared with one-way analysis of variance (ANOVA). For the paired comparison of significant variables, a statistically significant difference (HSD) test was used for Tukey's homogeneous variance variables. Statistical significance was set at p < 0.05. Results and Conclusions: We believe that our analysis results will be helpful in the control, prevention, immunological and therapeutic methods of the reactions (inflammation, rejection, etc.) that may occur in patients who are implanted with Titanium (Ti) and Titanium 500 (Ti 500) implants (spinal, orthopedic, dental etc.)

Fracture Toughness Of Nanoscale Zirconia Coatings On Titanium Substrates

In the biomedical field, the surface modification of titanium aims to inhibit wear, reduce corrosion and ion release, and promote biocompatibility. Sol-gel-derived ceramic nanoscale coatings show promise due to their relative ease of production, ability to form a physically and chemically uniform coating over complex geometric shapes, and their potential to deliver exceptional mechanical properties due to their nanocrystalline structure. In this study zirconia coatings on titanium were investigated for their fracture toughness

A novel metallurgical bonding process and microstructural analysis of ferrous alloy composites

A group of ferrous alloy composites have been produced using a novel vacuum casting process. The bonding and the interfacial analysis of these composites has been studied using various techniques including: optical microscopy, energy dispersive spectroscopy (EDS) microanalysis, X-ray mapping (XRM) and electron back scattered diffraction (EBSD). A number of phase changes and unique microstructural features have been observed. Some of these microstructural features are the result of the solidification process, whilst other changes have resulted from diffusion of elements across the composite interface. This study demonstrates the uniqueness of the vacuum casting process as an efficient bonding process and the importance of comparing data from a variety of analytical techniques to enable a thorough model of the solidification and diffusion processes to be properly developed. © Institute of Materials Engineering Australasia Ltd

Conversion of ostrich eggshells (Struthio camelus) to calcium phosphates

© Copyright 2015, The Australian Ceramic Society. The exceptional progress made in orthopaedic and dental applications have increased the demand of calcium phosphate bioceramics due to their chemical similarities to the inorganic component of hard tissues. Low cost production of calcium phosphate bioceramics could be achieved by using pure natural biogenic materials by relatively simple methods. In this study calcium phosphate powders were produced from ostrich (Struthio camelus) eggshell powder at a moderate temperature of 80°C by relatively simple process of low temperature heating by hot plate (HP) and hot platting while agitation with ultrasonication (HPUS) hence introducing mechanical activation. The product structure and compositions were studied with FTIR, SEM, DTA/TCA, XRD and ICP techniques. The results showed that calcium deficient hydroxyapatite and dicalcium phosphate were obtained from HP and HPUS methods. Poorly crystalline calcium deficient hydroxyapatite was converted into whilockite after calcining at 800°C. The results suggest that this low cost and relatively simple method is efficient to easily produce calcium phosphate powders from adequately feed controlled farms to obtain pure uncontaminated eggshells for a range of biomedical applications

Specifiable biomimetic microsponges for timed release of crystal entrapped biomolecules useful in bone repair.

Most marine materials, by nature, contain crystals of inorganic matter with specific structures that allow the loading, release, and delivery of biomolecules that can be utilized in clinical applications. These structures can be biomimetically synthesized. Aggregates of inorganic particles generated by biomimetic microsponges may provide surfaces and structures for cell attachment, organization, and promotion of matrix synthesis. Biomimetic microsponges have been developed with tunable release profiles differing by the rate (speed over distance), velocity (rate of change in direction), and the quantity discharged over time, according to biomolecular species. Specifically, the types of proteins involved guide and regulate cells in physical contact with the microsponges, for instance, reprogramming somatic cells, the switching phenotypes, or specifying stem cell differentiation. Applications for these microsponges include gene transfection of localized cells and promotion of bone matrix synthesis by the externalized display of RGD cell adhesive peptides and the release of crystal entrapped, occluded, adsorbed and infused rhBMP-2 and plasmid. A requirement for de novo bone formation is a solid structure to enable osteocytes to lay new bone tissue. In this study, biomimetic microsponges highlight tremendous potential as osteoconductive packing material in bone repair with parallel influence on regeneration. Majorly, microsponges offer pronounced osteoinductivity, unlike many other bone particulates, by solid-state integration of active regenerative biological molecules through the prism of the biomineral crystalline structure

Marine structure derived calcium phosphate-polymer biocomposites for local antibiotic delivery

© 2015 by the authors. Hydrothermally converted coralline hydroxyapatite (HAp) particles loaded with medically active substances were used to develop polylactic acid (PLA) thin film composites for slow drug delivery systems. The effects of HAp particles within PLA matrix on the gentamicin (GM) release and release kinetics were studied. The gentamicin release kinetics seemed to follow Power law Korsmeyer Peppas model with mainly diffusional process with a number of different drug transport mechanisms. Statistical analysis shows very significant difference on the release of gentamicin between GM containing PLA (PLAGM) and GM containing HAp microspheres within PLA matrix (PLAHApGM) devices, which PLAHApGM displays lower release rates. The use of HAp particles improved drug stabilization and higher drug encapsulation efficiency of the carrier. HAp is also the source of Ca2+ for the regeneration and repair of diseased bone tissue. The release profiles, exhibited a steady state release rate with significant antimicrobial activity against Staphylococcus aureus (S. aureus) (SH1000) even at high concentration of bacteria. The devices also indicated significant ability to control the growth of bacterial even after four weeks of drug release. Clinical release profiles can be easily tuned from drug-HAp physicochemical interactions and degradation kinetics of polymer matrix. The developed systems could be applied to prevent microbial adhesion to medical implant surfaces and to treat infections mainly caused by S. aureus in surgery

Bone regeneration of calvarial defect using marine calcareous-derived beta-tricalcium phosphate macrospheres

© 2014, © The Author(s) 2014. The aim of this study was to examine the bone regeneration properties of beta-tricalcium phosphate hydrothermally converted from foraminifera carbonate exoskeleton in the repair of rat calvarial defect. These natural materials possess unique interconnected porous network with uniform pore size distribution, which can be potentially advantageous. In total, 20 adult male Wistar rats received full-thickness calvarial defect with a diameter of 5 mm. The rate of newly formed bone was measured radiologically by X-ray and micro-computed tomography and by histologic examination. After 2 weeks, the beta-tricalcium phosphate group exhibited full closure of the defect site, while control group remained unrestored at the end of the 6-week experimentation. It was observed that the newly regenerated bone thickened over the course of the experiment in the beta-tricalcium phosphate group. No soft tissue reaction was observed around the beta-tricalcium phosphate implant and the rats remained healthy. These results showed that repair of the calvarial defect can be achieved by biomimetic beta-tricalcium phosphate macrospheres, which hold potential for application as bone grafts for bone augmentation surgeries