Background: Surface topography is a key parameter in bone cells-biomaterials interactions. This study analyzed the behavior of human osteoclast precursor cells cultured over three hydroxyapatite (HA) surfaces ranging from a micro- to nanoscale topography.
Methods: HA surfaces were prepared with microsized HA particles, at 1300°C (HA1), and with nanosized HA particles at 1000°C (HA2) and 830°C (HA3). Human osteoclast precursors were cultured in the absence or presence of M-SCF and RANKL.
Results: HA surfaces had similar chemical composition, however, HA1 and HA3 presented typical micro- and nanostructured topographies, respectively, and HA2 profile was between those of HA1 and HA3. The decrease on the average grain diameter to the nanoscale range (HA3) was accompanied by an increase in surface area, porosity and hydrophilicity and a decrease in roughness. Compared to HA1 surface, HA3 allowed a lower osteoclastic adhesion, differentiation and function. Differences in the cell response appeared to be associated with the modulation of relevant intracellular signaling pathways.
Conclusions: The decrease in HA grain size to a biomimetic nanoscale range, appears less attractive to osteoclastic differentiation and function, compared to the HA microsized topography.
General Significance: This observation emphasizes the role of surface topography in designing advanced biomaterials for tailored bone cells response in regenerative strategies.
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http://dx.doi.org/10.1016/j.bbagen.2016.01.014 | DOI Listing |
J Immunother Cancer
January 2025
Department of Oncology, Taipei Veterans General Hospital, Taipei, Taiwan
Background: Cholangiocarcinoma is a challenging malignancy with limited responses to conventional therapies, particularly immune checkpoint inhibitor therapy. Tumor-infiltrating lymphocytes (TILs) and tertiary lymphoid structures (TLSs) are key components of the tumor microenvironment (TME) and have been implicated in the immune response to cancer. However, the role and difference of TLSs and TILs in patients with cholangiocarcinoma remains unclear.
View Article and Find Full Text PDFAm J Physiol Cell Physiol
January 2025
Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro.
O-GlcNAcylation is a post-translational modification characterized by the covalent attachment of a single moiety of GlcNAc on serine/threonine residues in proteins. Tyrosine hydroxylase (TH), the rate-limiting step enzyme in the catecholamine synthesis pathway and responsible for production of the dopamine precursor, L-DOPA, has its activity regulated by phosphorylation. Here, we show an inverse feedback mechanism between O-GlcNAcylation and phosphorylation of TH at serine 40 (TH pSer40).
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2025
Department of Marine Microbiology and Biogeochemistry, Royal Netherlands Institute for Sea Research (NIOZ), Den Burg 1790 AB, The Netherlands.
Heterocytes, specialized cells for nitrogen fixation in cyanobacteria, are surrounded by heterocyte glycolipids (HGs), which contribute to protection of the nitrogenase enzyme from oxygen. Diverse HGs preserve in the sediment and have been widely used as evidence of past nitrogen fixation, and structural variation has been suggested to preserve taxonomic information and reflect paleoenvironmental conditions. Here, by comprehensive HG identification and screening of HG biosynthetic gene clusters throughout cyanobacteria, we reconstruct the convergent evolutionary history of HG structure, in which different clades produce the same HGs.
View Article and Find Full Text PDFPathol Int
January 2025
Department of Cancer Pathology, Graduate School of Medicine, Hokkaido University, Hokkaido, Japan.
Recent studies suggest that lung adenocarcinoma cells are closely associated with the tumorigenesis of large-cell neuroendocrine carcinoma via cellular transformation. However, morphological evidence, along with genetic abnormalities before, during, and after transformation, is quite limited. We present here a case of combined large-cell neuroendocrine carcinoma and adenocarcinoma exhibiting acinar and solid patterns.
View Article and Find Full Text PDFJ Med Virol
February 2025
Department of Chemistry, Assam University, Silchar, India.
The biological applications of noncationic porphyrin-fullerene (P-F) dyads as anti-HIV agents have been limited despite the established use of several cationic P-F dyads as anti-cancer photodynamic therapy (PDT) agents. This article explores the potential of amphiphilic non-cationic porphyrin-fullerene dyads as HIV-1 inhibitors under both PDT (light-treated) and non-PDT (dark) conditions. The amphiphilic P-F dyads, PBC and PBC, demonstrated enhanced efficacy in inhibiting the entry and production of HIV-1 (subtypes B and C).
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