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Pujari, Shiuli
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Publications (10 of 18) Show all publications
Janson, O., Gururaj, S., Pujari-Palmer, S., Karlsson Ott, M., Strømme, M., Engqvist, H. & Welch, K. (2019). Titanium surface modification to enhance antibacterial and bioactive properties while retaining biocompatibility. Materials science & engineering. C, biomimetic materials, sensors and systems, 96, 272-279
Open this publication in new window or tab >>Titanium surface modification to enhance antibacterial and bioactive properties while retaining biocompatibility
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2019 (English)In: Materials science & engineering. C, biomimetic materials, sensors and systems, ISSN 0928-4931, E-ISSN 1873-0191, Vol. 96, p. 272-279Article in journal (Refereed) Published
Abstract [en]

Bacterial infections associated with metal implants are severe problems affecting a considerable amount of people with dental or orthopedic implants. This study aims to examine the antibacterial effect of a Titanium-peroxy gel layer on the modified surface of commercially pure titanium grade 2. Variations in a multi-step surface modification procedure were tested to determine the best combination that provided an antibacterial effect while enhancing bioactivity without compromising biocompatibility. Soaking the surfaces in 30 wt% hydrogen peroxide held at 80 °C provided antibacterial activity while subsequent surface treatments in concentrated sodium and calcium hydroxide solutions were preformed to enhance bioactivity. Staphylococcus epidermidis was used to determine the antibacterial effect through both direct contact and biofilm inhibition tests while human dermal fibroblast cells and MC3T3 pre osteoblast cells were utilized to test biocompatibility. The greatest antibacterial effect was observed with only hydrogen peroxide treatment, but the resulting surface was neither bioactive nor biocompatible. It was found that subsequent surface treatments with sodium hydroxide followed by calcium hydroxide provided a bioactive surface that was also biocompatible. Additionally, a final treatment with autoclaving showed positive effects with regards to enhanced bioactivity. This multi-step surface modification procedure offers a promising, non-antibiotic, solution for combatting infections associated with biomedical implants.

Keywords
Titanium, Antibacterial, Bioactivity, Cell viability, Sodium titanate, Calcium titanate
National Category
Materials Engineering
Identifiers
urn:nbn:se:uu:diva-358023 (URN)10.1016/j.msec.2018.11.021 (DOI)000456760700027 ()30606532 (PubMedID)
Funder
Vinnova
Available from: 2018-08-23 Created: 2018-08-23 Last updated: 2019-03-15Bibliographically approved
Pujari-Palmer, S., Lu, X., Singh, V. P., Engman, L., Pujari-Palmer, M. & Karlsson Ott, M. (2017). Incorporation and delivery of an organoselenium antioxidant from a brushite cement. Materials letters (General ed.), 197, 115-119
Open this publication in new window or tab >>Incorporation and delivery of an organoselenium antioxidant from a brushite cement
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2017 (English)In: Materials letters (General ed.), ISSN 0167-577X, E-ISSN 1873-4979, Vol. 197, p. 115-119Article in journal (Refereed) Published
Abstract [en]

An inflammatory reaction occurs following biomaterial implantation in the body, which produce toxic byproducts such as reactive oxygen species (ROS). Although ROS is required to clear the wound, excessive ROS can damage the tissue around the implant site, eventually leading to implant failure. One approach to control the inflammatory response is to incorporate an antioxidant into the biomaterial in order to scavenge ROS produced by activated phagocytes. In the present study, an organoselenium antioxidative compound was incorporated into a brushite cement, with the goal of scavenging ROS generated from activated primary human mononuclear leukocytes (MNCs), in vitro. The effect of the antioxidant on the physical properties of brushite cement, and its release from the cement were investigated via compressive strength, setting time, phase composition, and UV spectroscopy analysis. The physical properties of brushite remained unchanged following incorporation of the antioxidant. The antioxidant was slowly released from the cement, following a non-Fickian transport mechanism, with approximately 60% of the loaded antioxidant released over five days. The released antioxidant was then tested for its ability to scavenge ROS released by MNCs using the luminol amplified chemiluminescence assay. The results show that antioxidative released at both early stages (24 h) and late stages (120 h) retained its scavenging capacity and effectively reduced ROS production. These results indicate that brushite cements loaded with organoselenium compounds can modulate ROS production after implantation and potentially modulate the inflammatory response to improve device integration.

Keywords
Antioxidants, Reactive oxygen species, Calcium phosphate cements, Inflammation, Biomaterial, Drug delivery
National Category
Materials Engineering
Identifiers
urn:nbn:se:uu:diva-322444 (URN)10.1016/j.matlet.2017.03.139 (DOI)000399500300031 ()
Funder
Carl Tryggers foundation , CTS 13:346Magnus Bergvall Foundation, 2015-01111Stiftelsen Längmanska kulturfonden, 16-2-41
Available from: 2017-05-23 Created: 2017-05-23 Last updated: 2017-05-23Bibliographically approved
Pujari-Palmer, S., Chen, S., Rubino, S., Weng, H., Xia, W., Engqvist, H., . . . Ott, M. K. (2016). In vivo and in vitro evaluation of hydroxyapatite nanoparticle morphology on the acute inflammatory response. Biomaterials, 90, 1-11
Open this publication in new window or tab >>In vivo and in vitro evaluation of hydroxyapatite nanoparticle morphology on the acute inflammatory response
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2016 (English)In: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 90, p. 1-11Article in journal (Refereed) Published
Abstract [en]

Biomedical implants have been widely used in bone repair applications. However, nanosized degradation products from these implants could elicit an inflammatory reaction, which may lead to implant failure. It is well known that the size, chemistry, and charge of these nanoparticles can modulate this response, but little is known regarding the role that the particle's morphology plays in inducing inflammation. The present study aims to investigate the effect of hydroxyapatite nanoparticle (HANPs) morphology on inflammation, in-vitro and in-vivo. Four distinct HANP morphologies were fabricated and characterized: long rods, dots, sheets, and fibers. Primary human polymorphonuclear cells (PMNCs), mononuclear cells (MNCs), and human dermal fibroblasts (hDFs) were exposed to HANPs and alterations in cell viability, morphology, apoptotic activity, and reactive oxygen species (ROS) production were evaluated, in vitro. PMNCs and hDFs experienced a 2-fold decrease in viability following exposure to fibers, while MNC viability decreased 5-fold after treatment with the dots. Additionally, the fibers stimulated an elevated ROS response in both PMNCs and MNCs, and the largest apoptotic behavior for all cell types. Furthermore, exposure to fibers and dots resulted in greater capsule thickness when implanted subcutaneously in mice. Collectively, these results suggest that nanoparticle morphology can significantly impact the inflammatory response.

Keywords
Hydroxyapatite nanoparticles; Morphology; Mononuclear cells; Polymorphonuclear cells; Reactive oxygen species; In vivo
National Category
Immunology Biomaterials Science Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-283555 (URN)10.1016/j.biomaterials.2016.02.039 (DOI)000374618100001 ()26974703 (PubMedID)
Funder
VINNOVA, 2010-01907
Available from: 2016-04-13 Created: 2016-04-13 Last updated: 2018-02-08Bibliographically approved
Pujari-Palmer, S. (2016). Nanofeatures of Biomaterials and their Impact on the Inflammatory Response. (Doctoral dissertation). Uppsala: Acta Universitatis Upsaliensis
Open this publication in new window or tab >>Nanofeatures of Biomaterials and their Impact on the Inflammatory Response
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Nanomaterials offer an advantage over traditional biomaterials since cells naturally communicate via nanoscale interactions. The extracellular matrix, for example, modulates adhesion and cellular functions via nanoscale features. Thus incorporating nanofeatures into biomaterials may promote tissue regeneration, however in certain forms and doses nanomaterials can also cause harm. A thorough understanding of cell-nanomaterial interactions is therefore necessary to better design functional biomaterials. This thesis focuses on evaluating the effect of nanofeatures on inflammation using two different models: nanoporous alumina and hydroxyapatite nanoparticles (HANPs).

The inflammatory response caused by in vitro exposure of macrophages to nanoporous alumina, with pore diameters of 20nm and 200nm, was investigated. In addition in vivo studies were performed by implantation of nanoporous membranes in mice. In both cases the 200nm pore diameter elicited a stronger inflammatory response.

Nanoporous alumina with 20, 100 and 200nm pores were loaded with Trolox, a vitamin E analogue, in order to scavenge ROS produced by primary human polymorphonuclear (PMNC) and mononuclear (MNCs) leukocytes. Unloaded alumina membranes stimulated greater ROS production from PMNCs cultured on 20nm versus 100nm pores. This trend reversed when PMNCs were cultured on Trolox loaded membranes since Trolox eluted slower from 20nm than 100nm and 200nm pores. ROS produced from PMNCs was reduced between 8-30% when cultured on Trolox loaded membranes. For MNCs, ROS production was not affected by pore size. However when the alumina was loaded with Trolox ROS production was quenched by 95%.

HANPs with distinct morphologies (long rods, sheets, dots, and fibers) were synthesized via hydrothermal and precipitation methods. The HANPs were then exposed to PMNCs, MNCs, and the human dermal fibroblast (hDF) cell line. Changes in cell viability, ROS, morphology, and apoptotic behavior were evaluated. PMNC and hDF viability decreased following exposure to fibers, while the dot particles reduced MNC viability. Fibers stimulated greater ROS production from PMNCs and MNCs, and caused apoptotic behavior in all cell types. Furthermore, they also stimulated greater capsule thickness in vivo, suggesting that nanoparticle morphology can significantly influence acute inflammation.

The outcome of this thesis, confirms the importance of understanding how nanofeatures influence inflammation.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2016. p. 70
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1374
Keywords
Nanofeatures, alumina, hydroxyapatite, inflammation
National Category
Nano Technology Biological Sciences Materials Engineering
Research subject
Engineering Science with specialization in Materials Science
Identifiers
urn:nbn:se:uu:diva-284402 (URN)978-91-554-9576-3 (ISBN)
Public defence
2016-06-09, Å2001, Lägerhyddsvägen 1, Uppsala, 09:30 (English)
Opponent
Supervisors
Available from: 2016-05-19 Created: 2016-04-18 Last updated: 2016-06-01
Pujari-Palmer, S., Pujari-Palmer, M. & Karlsson Ott, M. (2016). Reduced oxidative stress in primary human cells by antioxidant released from nanoporous alumina. Journal of Biomedical Materials Research. Part B - Applied biomaterials, 104(3), 568-575
Open this publication in new window or tab >>Reduced oxidative stress in primary human cells by antioxidant released from nanoporous alumina
2016 (English)In: Journal of Biomedical Materials Research. Part B - Applied biomaterials, ISSN 1552-4973, E-ISSN 1552-4981, Vol. 104, no 3, p. 568-575Article in journal (Refereed) Published
Abstract [en]

Nanoporous alumina elicits different inflammatory responses dependent on pore size, such as increased complement activation and reactive oxygen species (ROS) production, on 200 versus 20 nm pores. In this study, we attempt to further modulate inflammatory cell response by loading nanoporous alumina membranes (20, 100, and 200 nm pores), with an antioxidant, Trolox, for controlled drug release. For mononuclear cells (MNC) no difference in cell response, due to pore size, was seen when cultured on nonloaded membranes. However, when exposed to membranes loaded with Trolox, 100 uM was enough to quench ROS by more than 95% for all pore sizes. Polymorphonuclear cells (PMNC) produced significantly more ROS when exposed to 20 versus 100 nm pores. For Trolox loaded membranes, this trend reversed, due to slower release of antioxidant from the 20 nm pores. Furthermore, Trolox exhibited a unique effect on PMNCs that has not previously been reported: It delayed the production of ROS in a manner distinct from antioxidant activity. The present study confirms that nanoporous alumina is a suitable vehicle for drug delivery, and that Trolox can successfully modulate the inflammatory response of both MNC and PMNCs.

Keywords
nanoporous alumina; Trolox; mononuclear cells; polymorphonuclear cells; reactive oxygen species
National Category
Immunology Biomaterials Science Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-283488 (URN)10.1002/jbm.b.33427 (DOI)000372297100016 ()25952986 (PubMedID)
Funder
The Swedish Foundation for International Cooperation in Research and Higher Education (STINT)
Available from: 2016-04-13 Created: 2016-04-13 Last updated: 2017-11-30Bibliographically approved
Cai, Y., Pujari-Palmer, S., Gururaj, S., Fu, L., Chen, S., Engqvist, H., . . . Xia, W. (2016). Utilization of Translucent Hydroxyapatite Nano-Ceramics as a Bio-Window Material. Nano Advances, 1, 45-49
Open this publication in new window or tab >>Utilization of Translucent Hydroxyapatite Nano-Ceramics as a Bio-Window Material
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2016 (English)In: Nano Advances, Vol. 1, p. 45-49Article in journal (Refereed) Published
Abstract [en]

Bioceramic materials are importantlyused in the field ofhard tissue engineering. The direct detection of cell response is almost impossible for mostof bioceramics due to theiropaqueness. Thus,the live tracking of cell behavior cannot be performedon these ceramics. In this study, we proposea strategy thatdirect observation of cell growth through hydroxyapatite (HA)ceramics can be realized by employing a translucent hydroxyapatite (tHA) nano-ceramic. We obtained MC3T3 preosteoblast cells and cultured them in the presence of tHA for up to 7 days. The results show that MC3T3cells were able to be seen through the tHA. In addition, live fluorescent staining confirmed that the MC3T3 cells were viable throughout the culture time period. The findings reveal the as-fabricated tHA nano-ceramics can bepotentialas a bio-window material for cell adhesion and proliferation.

National Category
Nano Technology
Identifiers
urn:nbn:se:uu:diva-277119 (URN)
Available from: 2016-02-17 Created: 2016-02-17 Last updated: 2018-02-08Bibliographically approved
Chen, S., Pujari-Palmer, S., Rubino, S., Westlund, V., Ott, M., Engqvist, H. & Xia, W. (2015). Highly repeatable synthesis of nHA with high aspect ratio. Materials letters (General ed.), 159, 163-167
Open this publication in new window or tab >>Highly repeatable synthesis of nHA with high aspect ratio
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2015 (English)In: Materials letters (General ed.), ISSN 0167-577X, E-ISSN 1873-4979, Vol. 159, p. 163-167Article in journal (Refereed) Published
National Category
Biomaterials Science Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-265712 (URN)10.1016/j.matlet.2015.06.086 (DOI)000362603000043 ()
Funder
Swedish Research Council, 2013-5419VINNOVA, 2010-01907EU, FP7, Seventh Framework Programme, INFRA-2010-262163
Available from: 2015-11-02 Created: 2015-11-02 Last updated: 2018-02-08
Pujari-Palmer, S., Chen, S., Xia, W., Rubino, S., Weng, H., Tang, L. & Ott, M. (2015). Influence of hydroxyapatite nanoparticle morphology on inflammatory response. European Cells and Materials, 29(S1), 43
Open this publication in new window or tab >>Influence of hydroxyapatite nanoparticle morphology on inflammatory response
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2015 (English)In: European Cells and Materials, ISSN 1473-2262, E-ISSN 1473-2262, Vol. 29, no S1, p. 43-Article in journal, Meeting abstract (Refereed) Published
National Category
Medical Materials
Identifiers
urn:nbn:se:uu:diva-284216 (URN)
Available from: 2016-04-15 Created: 2016-04-15 Last updated: 2017-11-30
Pujari-Palmer, S., Chen, S., Xia, W., Rubino, S., Weng, H., Tang, L. & Karlsson Ott, M. (2015). Influence of hydroxyapatite nanoparticle morphology on inflammatory response. European Cells and Materials, 29
Open this publication in new window or tab >>Influence of hydroxyapatite nanoparticle morphology on inflammatory response
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2015 (English)In: European Cells and Materials, ISSN 1473-2262, E-ISSN 1473-2262, Vol. 29Article in journal (Refereed) Published
National Category
Biomaterials Science Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-266009 (URN)
Available from: 2015-11-04 Created: 2015-11-04 Last updated: 2017-12-01
Pujari-Palmer, S., Chen, S., Xia, W., Robino, S., Weng, H., Xia, W., . . . Ott, M. (2015). Influence of hydroxyapatite nanoparticle morphology on inflammatory response. In: : . Paper presented at 8th meeting of the Scandinavian Society for Biomaterials.
Open this publication in new window or tab >>Influence of hydroxyapatite nanoparticle morphology on inflammatory response
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2015 (English)Conference paper, Poster (with or without abstract) (Refereed)
National Category
Medical Materials
Identifiers
urn:nbn:se:uu:diva-284192 (URN)
Conference
8th meeting of the Scandinavian Society for Biomaterials
Available from: 2016-04-15 Created: 2016-04-15 Last updated: 2018-02-08
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