Publications by authors named "José Carlos Alcazar"

4 Publications

  • Page 1 of 1

Does Cryopreservation Affect the Biological Properties of Stem Cells from Dental Tissues? A Systematic Review.

Braz Dent J 2016 Oct-Dec;27(6):633-640

Post-Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, Brazil.

This systematic review evaluated if different cryopreservation protocols could affect biological properties (Cell survival rate (CSR), proliferation, differentiation, maintenance of stem cell markers) of stem cells obtained from dental tissues (DSC) post-thaw. An electronic search was carried out within PubMed and ISI Web Science by using specific keyword. Two independent reviewers read the titles and abstracts of all reports respecting predetermined inclusion/exclusion criteria. Data were extracted considering the biological properties of previously cryopreserved DSCs and previously cryopreserved dental tissues. DSCs cryopreserved as soon as possible after their isolation presents a CSR quite similar to the non-cryopreserved DSC. Dimethyl sulfoxide (DMSO) [10%] showed good results related to cell recovery post-thaw to cryopreserve cells and tissues for periods of up to 2 years. The cryopreservation of DSC in a mechanical freezer (-80°C) allows the recovery of stem cells post-thaw. The facilities producing magnetic field (MF), demand a lower concentration of cryoprotectant, but their use is not dispensable. It is possible to isolate and cryopreserve dental pulp stem cell (DPSC) from healthy and diseased vital teeth. Cryopreservation of dental tissues for late DSC isolation, combined with MF dispensability, could be valuable to reduce costs and improve the logistics to develop teeth banks.
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http://dx.doi.org/10.1590/0103-6440201600980DOI Listing
April 2017

Immunohistochemical Expression of TGF-β1 and Osteonectin in engineered and Ca(OH)2-repaired human pulp tissues.

Braz Oral Res 2016 Oct 10;30(1):e93. Epub 2016 Oct 10.

Universidade Federal de Pelotas, School of Dentistry,Post Graduation Program in Dentistry, Pelotas, Brazil.

The aim of the present study was to evaluate the expression of transforming growth factor-β1 (TGF-β1) and osteonectin (ON) in pulp-like tissues developed by tissue engineering and to compare it with the expression of these proteins in pulps treated with Ca(OH)2 therapy. Tooth slices were obtained from non-carious human third molars under sterile procedures. The residual periodontal and pulp soft tissues were removed. Empty pulp spaces of the tooth slice were filled with sodium chloride particles (250-425 µm). PLLA solubilized in 5% chloroform was applied over the salt particles. The tooth slice/scaffold (TS/S) set was stored overnight and then rinsed thoroughly to wash out the salt. Scaffolds were previously sterilized with ethanol (100-70°) and washed with phosphate-buffered saline (PBS). TS/S was treated with 10% EDTA and seeded with dental pulp stem cells (DPSC). Then, TS/S was implanted into the dorsum of immunodeficient mice for 28 days. Human third molars previously treated with Ca(OH)2 for 90 days were also evaluated. Samples were prepared and submitted to histological and immunohistochemical (with anti-TGF-β1, 1:100 and anti-ON, 1:350) analyses. After 28 days, TS/S showed morphological characteristics similar to those observed in dental pulp treated with Ca(OH)2. Ca(OH)2-treated pulps showed the usual repaired pulp characteristics. In TS/S, newly formed tissues and pre-dentin was colored, which elucidated the expression of TGF-β1 and ON. Immunohistochemistry staining of Ca(OH)2-treated pulps showed the same expression patterns. The extracellular matrix displayed a fibrillar pattern under both conditions. Regenerative events in the pulp seem to follow a similar pattern of TGF-β1 and ON expression as the repair processes.
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http://dx.doi.org/10.1590/1807-3107BOR-2016.vol30.0093DOI Listing
October 2016

Electrochemical Cathodic Polarization, a Simplified Method That Can Modified and Increase the Biological Activity of Titanium Surfaces: A Systematic Review.

PLoS One 2016 21;11(7):e0155231. Epub 2016 Jul 21.

Department of Restorative Dentistry, Post-Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.

Background: The cathodic polarization seems to be an electrochemical method capable of modifying and coat biomolecules on titanium surfaces, improving the surface activity and promoting better biological responses.

Objective: The aim of the systematic review is to assess the scientific literature to evaluate the cellular response produced by treatment of titanium surfaces by applying the cathodic polarization technique.

Data, Sources, And Selection: The literature search was performed in several databases including PubMed, Web of Science, Scopus, Science Direct, Scielo and EBSCO Host, until June 2016, with no limits used. Eligibility criteria were used and quality assessment was performed following slightly modified ARRIVE and SYRCLE guidelines for cellular studies and animal research.

Results: Thirteen studies accomplished the inclusion criteria and were considered in the review. The quality of reporting studies in animal models was low and for the in vitro studies it was high. The in vitro and in vivo results reported that the use of cathodic polarization promoted hydride surfaces, effective deposition, and adhesion of the coated biomolecules. In the experimental groups that used the electrochemical method, cellular viability, proliferation, adhesion, differentiation, or bone growth were better or comparable with the control groups.

Conclusions: The use of the cathodic polarization method to modify titanium surfaces seems to be an interesting method that could produce active layers and consequently enhance cellular response, in vitro and in vivo animal model studies.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0155231PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4956102PMC
July 2017

Influence of poly-L-lactic acid scaffold's pore size on the proliferation and differentiation of dental pulp stem cells.

Braz Dent J 2015 Mar-Apr;26(2):93-8. Epub 2015 Apr 1.

Post-Graduate Program in Dentistry, Dental School, UFPel - Federal University of Pelotas, Pelotas, RS, Brazil.

The aim of this study was to evaluate the influence of the poly-L-lactic acid (PLLA)-based scaffold's pore size on the proliferation and differentiation of dental pulp stem cells (DPSCs). The scaffolds were prepared in pulp chambers of 1-mm-thick tooth slices from third molars using salt crystals (150-250 µm or 251-450 µm) as porogen. DPSC (1x105 cells) were seeded in the scaffolds with different pore sizes, and cultured in 24-well plates. The cell proliferation was evaluated using the WST-1 assay after 3-21 days. Furthermore, RT-PCR was used to assess the differentiation of the DPSCs into odontoblasts, using markers of odontoblastic differentiation (DSPP, DSP-1 and MEPE). RNA from human odontoblasts was used as control. Cell proliferation rate was similar in both scaffolds except at the 14th day period, in which the cells seeded in the scaffolds with larger pores showed higher proliferation (p<0.05). After 21 days DPSCs seeded in both evaluated scaffolds were able of expressing odontoblastic markers DMP-1, DSPP and MEPE. In summary, both scaffolds tested in this study allowed the proliferation and differentiation of DPSCs into odontoblast-like cells.
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http://dx.doi.org/10.1590/0103-6440201300032DOI Listing
December 2016