In vitro antibacterial evaluation of sol-gel-derived Zn-, Ag-, and (Zn + Ag)-doped hydroxyapatite coatings against methicillin-resistant Staphylococcus aureus.
ABSTRACT Hydroxyapatite (HAp) coatings were applied using sol-gel method. Phosphor pentoxide and calcium nitrate were used as phosphorous and calcium precursors, respectively. Zinc nitrate and silver nitrate were used as substitute of calcium in HAp structure. As a base concentration, 1.5 wt %Ag and 2.5 wt %Zn were used. The weight percent of Ag was increased at 0.3 wt% and Zn content was scaled down at 0.5 wt%. Phase analysis and chemical bonds of synthesized materials were studied by XRD and FTIR. Antibacterial activity of Ag- and Zn-doped samples against methicilin-resistant Staphylococcus aureus (MRSA) were assessed by the plate-counting method. The XRD and FTIR results proved formation of HAp compound. Colony counting showed that silver and zinc ions prevent proliferation and growth of MRSA. Interestingly, co-presence of metal ions improves the antibacterial effectiveness of the coatings and the combined effect was greater than sum of the individual effects when each was administered alone. Overall, synergism between antibacterial activities of Zn(2+) and Ag(+) ions against MRSA can be suggested. Thus, cell toxicity decreases and biocompatibility increases without any decrement in antibacterial activity. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
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ABSTRACT: The purpose of this review is to present the most recent findings in bone tissue engineering. Special attention is given to multifunctional materials based on collagen and collagen-hydroxyapatite composites used for skin and bone cancer treatments. The multi-functionality of these materials was obtained by adding to the base regenerative grafts proper components, such as ferrites (magnetite being the most important representative), cytostatics (cisplatin, carboplatin, vincristine, methotrexate, paclitaxel, doxorubicin), silver nanoparticles, antibiotics (anthracyclines, geldanamycin), and/or analgesics (ibuprofen, fentanyl). The suitability of complex systems for the intended applications was systematically analyzed. The developmental possibilities of multifunctional materials with regenerative and curative roles (antitumoral as well as pain management) in the field of skin and bone cancer treatment are discussed. It is worth mentioning that better materials are likely to be developed by combining conventional and unconventional experimental strategies.International Journal of Nanomedicine 01/2014; 9:2713-2725. · 4.20 Impact Factor
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ABSTRACT: Hydroxyapatite nanoparticles (HAP NPs) are one of the widely used biocompatible materials. However, information about the reaction between HAP NPs and microorganisms is insufficient. This paper aims to understand the antibacterial property of a new nanocomposite consisting of gold-coated HAP and alginate polymer (namely, Au-HAP@Alg NPs). To the best of our knowledge, we reported the first information regarding to MIC (25mg/mL), DIZ (no visible zone), and IC50 (0.5mg/mL) of Au-HAP@Alg NPs toward the microorganism Escherichia coli TOP10. The real-time gene expression levels of polA, polB, cyd, mdoG, GAPDH, and 16S rRNA were maintained at stable levels up until conditions of 2.5mg/mL Au-HAP@Alg NPs. The results showed that 16S rRNA can be a good reference under these conditions. The expressions of GAPDH, cyd, and mdoG were inhibited obviously under condition of 10mg/mL of Au-HAP@Alg NPs. Our results indicated that the possible antibacterial mechanism of Au-HAP@Alg was through the interaction with these carbohydrate and cell wall-related genes. This novel biocompatible and antibacterial material can potentially be applied in medical and environmental fields.Journal of hazardous materials 11/2013; · 4.33 Impact Factor
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ABSTRACT: Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also presenting low toxicity to the human cells. Such factors are usually implemented along with the implant itself and may be an integral part of it. Many recent studies have focused on inorganic factors, such as metal nanoparticles, salts, and metal oxides. The advantages of inorganic factors include the ease with which they can be combined with ceramic and polymeric biomaterials. The following review focuses on hydroxyapatites substituted with ions with antibacterial properties. It considers materials that have already been applied in regenerative medicine (e.g., hydroxyapatites with silver ions) and those that are only at the preliminary stage of research and which could potentially be used in implantology or dentistry. We present methods for the synthesis of modified apatites and the antibacterial mechanisms of various ions as well as their antibacterial efficiency.BioMed Research International 01/2014; 2014:178123. · 2.71 Impact Factor